Resguardo inicial

linux-7.2.3/security/keys/Kconfig

@@ -0,0 +1,131 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Key management configuration
+#
+
+menuconfig KEYS
+	bool "Enable access key retention support"
+	select ASSOCIATIVE_ARRAY
+	help
+	  This option provides support for retaining authentication tokens and
+	  access keys in the kernel.
+
+	  It also includes provision of methods by which such keys might be
+	  associated with a process so that network filesystems, encryption
+	  support and the like can find them.
+
+	  Furthermore, a special type of key is available that acts as keyring:
+	  a searchable sequence of keys. Each process is equipped with access
+	  to five standard keyrings: UID-specific, GID-specific, session,
+	  process and thread.
+
+	  If you are unsure as to whether this is required, answer N.
+
+if KEYS
+
+config KEYS_REQUEST_CACHE
+	bool "Enable temporary caching of the last request_key() result"
+	help
+	  This option causes the result of the last successful request_key()
+	  call that didn't upcall to the kernel to be cached temporarily in the
+	  task_struct.  The cache is cleared by exit and just prior to the
+	  resumption of userspace.
+
+	  This allows the key used for multiple step processes where each step
+	  wants to request a key that is likely the same as the one requested
+	  by the last step to save on the searching.
+
+	  An example of such a process is a pathwalk through a network
+	  filesystem in which each method needs to request an authentication
+	  key.  Pathwalk will call multiple methods for each dentry traversed
+	  (permission, d_revalidate, lookup, getxattr, getacl, ...).
+
+config PERSISTENT_KEYRINGS
+	bool "Enable register of persistent per-UID keyrings"
+	help
+	  This option provides a register of persistent per-UID keyrings,
+	  primarily aimed at Kerberos key storage.  The keyrings are persistent
+	  in the sense that they stay around after all processes of that UID
+	  have exited, not that they survive the machine being rebooted.
+
+	  A particular keyring may be accessed by either the user whose keyring
+	  it is or by a process with administrative privileges.  The active
+	  LSMs gets to rule on which admin-level processes get to access the
+	  cache.
+
+	  Keyrings are created and added into the register upon demand and get
+	  removed if they expire (a default timeout is set upon creation).
+
+config BIG_KEYS
+	bool "Large payload keys"
+	depends on TMPFS
+	select CRYPTO_LIB_CHACHA20POLY1305
+	help
+	  This option provides support for holding large keys within the kernel
+	  (for example Kerberos ticket caches).  The data may be stored out to
+	  swapspace by tmpfs.
+
+	  If you are unsure as to whether this is required, answer N.
+
+config TRUSTED_KEYS
+	tristate "TRUSTED KEYS"
+	help
+	  This option provides support for creating, sealing, and unsealing
+	  keys in the kernel. Trusted keys are random number symmetric keys,
+	  generated and sealed by a trust source selected at kernel boot-time.
+	  Userspace will only ever see encrypted blobs.
+
+	  If you are unsure as to whether this is required, answer N.
+
+if TRUSTED_KEYS
+source "security/keys/trusted-keys/Kconfig"
+endif
+
+config ENCRYPTED_KEYS
+	tristate "ENCRYPTED KEYS"
+	select CRYPTO
+	select CRYPTO_AES
+	select CRYPTO_CBC
+	select CRYPTO_LIB_SHA256
+	help
+	  This option provides support for create/encrypting/decrypting keys
+	  in the kernel.  Encrypted keys are instantiated using kernel
+	  generated random numbers or provided decrypted data, and are
+	  encrypted/decrypted with a 'master' symmetric key. The 'master'
+	  key can be either a trusted-key or user-key type. Only encrypted
+	  blobs are ever output to Userspace.
+
+	  If you are unsure as to whether this is required, answer N.
+
+config USER_DECRYPTED_DATA
+	bool "Allow encrypted keys with user decrypted data"
+	depends on ENCRYPTED_KEYS
+	help
+	  This option provides support for instantiating encrypted keys using
+	  user-provided decrypted data.  The decrypted data must be hex-ascii
+	  encoded.
+
+	  If you are unsure as to whether this is required, answer N.
+
+config KEY_DH_OPERATIONS
+       bool "Diffie-Hellman operations on retained keys"
+       select CRYPTO
+       select CRYPTO_KDF800108_CTR
+       select CRYPTO_DH
+       help
+	 This option provides support for calculating Diffie-Hellman
+	 public keys and shared secrets using values stored as keys
+	 in the kernel.
+
+	 If you are unsure as to whether this is required, answer N.
+
+config KEY_NOTIFICATIONS
+	bool "Provide key/keyring change notifications"
+	depends on WATCH_QUEUE
+	help
+	  This option provides support for getting change notifications
+	  on keys and keyrings on which the caller has View permission.
+	  This makes use of pipes to handle the notification buffer and
+	  provides KEYCTL_WATCH_KEY to enable/disable watches.
+
+endif # KEYS

linux-7.2.3/security/keys/Makefile

@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for key management
+#
+
+#
+# Core
+#
+obj-y := \
+	gc.o \
+	key.o \
+	keyring.o \
+	keyctl.o \
+	permission.o \
+	process_keys.o \
+	request_key.o \
+	request_key_auth.o \
+	user_defined.o
+compat-obj-$(CONFIG_KEY_DH_OPERATIONS) += compat_dh.o
+obj-$(CONFIG_COMPAT) += compat.o $(compat-obj-y)
+obj-$(CONFIG_PROC_FS) += proc.o
+obj-$(CONFIG_SYSCTL) += sysctl.o
+obj-$(CONFIG_PERSISTENT_KEYRINGS) += persistent.o
+obj-$(CONFIG_KEY_DH_OPERATIONS) += dh.o
+obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += keyctl_pkey.o
+
+#
+# Key types
+#
+obj-$(CONFIG_BIG_KEYS) += big_key.o
+obj-$(CONFIG_TRUSTED_KEYS) += trusted-keys/
+obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/

linux-7.2.3/security/keys/big_key.c

@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Large capacity key type
+ *
+ * Copyright (C) 2017-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) "big_key: "fmt
+#include <linux/init.h>
+#include <linux/seq_file.h>
+#include <linux/file.h>
+#include <linux/shmem_fs.h>
+#include <linux/err.h>
+#include <linux/random.h>
+#include <keys/user-type.h>
+#include <keys/big_key-type.h>
+#include <crypto/chacha20poly1305.h>
+
+/*
+ * Layout of key payload words.
+ */
+struct big_key_payload {
+	u8 *data;
+	struct path path;
+	size_t length;
+};
+#define to_big_key_payload(payload)			\
+	(struct big_key_payload *)((payload).data)
+
+/*
+ * If the data is under this limit, there's no point creating a shm file to
+ * hold it as the permanently resident metadata for the shmem fs will be at
+ * least as large as the data.
+ */
+#define BIG_KEY_FILE_THRESHOLD (sizeof(struct inode) + sizeof(struct dentry))
+
+/*
+ * big_key defined keys take an arbitrary string as the description and an
+ * arbitrary blob of data as the payload
+ */
+struct key_type key_type_big_key = {
+	.name			= "big_key",
+	.preparse		= big_key_preparse,
+	.free_preparse		= big_key_free_preparse,
+	.instantiate		= generic_key_instantiate,
+	.revoke			= big_key_revoke,
+	.destroy		= big_key_destroy,
+	.describe		= big_key_describe,
+	.read			= big_key_read,
+	.update			= big_key_update,
+};
+
+/*
+ * Preparse a big key
+ */
+int big_key_preparse(struct key_preparsed_payload *prep)
+{
+	struct big_key_payload *payload = to_big_key_payload(prep->payload);
+	struct file *file;
+	u8 *buf, *enckey;
+	ssize_t written;
+	size_t datalen = prep->datalen;
+	size_t enclen = datalen + CHACHA20POLY1305_AUTHTAG_SIZE;
+	int ret;
+
+	BUILD_BUG_ON(sizeof(*payload) != sizeof(prep->payload.data));
+
+	if (datalen == 0 || datalen > 1024 * 1024 || !prep->data)
+		return -EINVAL;
+
+	/* Set an arbitrary quota */
+	prep->quotalen = 16;
+
+	payload->length = datalen;
+
+	if (datalen > BIG_KEY_FILE_THRESHOLD) {
+		/* Create a shmem file to store the data in.  This will permit the data
+		 * to be swapped out if needed.
+		 *
+		 * File content is stored encrypted with randomly generated key.
+		 * Since the key is random for each file, we can set the nonce
+		 * to zero, provided we never define a ->update() call.
+		 */
+		loff_t pos = 0;
+
+		buf = kvmalloc(enclen, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+
+		/* generate random key */
+		enckey = kmalloc(CHACHA20POLY1305_KEY_SIZE, GFP_KERNEL);
+		if (!enckey) {
+			ret = -ENOMEM;
+			goto error;
+		}
+		ret = get_random_bytes_wait(enckey, CHACHA20POLY1305_KEY_SIZE);
+		if (unlikely(ret))
+			goto err_enckey;
+
+		/* encrypt data */
+		chacha20poly1305_encrypt(buf, prep->data, datalen, NULL, 0,
+					 0, enckey);
+
+		/* save aligned data to file */
+		file = shmem_kernel_file_setup("", enclen, EMPTY_VMA_FLAGS);
+		if (IS_ERR(file)) {
+			ret = PTR_ERR(file);
+			goto err_enckey;
+		}
+
+		written = kernel_write(file, buf, enclen, &pos);
+		if (written != enclen) {
+			ret = written;
+			if (written >= 0)
+				ret = -EIO;
+			goto err_fput;
+		}
+
+		/* Pin the mount and dentry to the key so that we can open it again
+		 * later
+		 */
+		payload->data = enckey;
+		payload->path = file->f_path;
+		path_get(&payload->path);
+		fput(file);
+		kvfree_sensitive(buf, enclen);
+	} else {
+		/* Just store the data in a buffer */
+		void *data = kmalloc(datalen, GFP_KERNEL);
+
+		if (!data)
+			return -ENOMEM;
+
+		payload->data = data;
+		memcpy(data, prep->data, prep->datalen);
+	}
+	return 0;
+
+err_fput:
+	fput(file);
+err_enckey:
+	kfree_sensitive(enckey);
+error:
+	kvfree_sensitive(buf, enclen);
+	return ret;
+}
+
+/*
+ * Clear preparsement.
+ */
+void big_key_free_preparse(struct key_preparsed_payload *prep)
+{
+	struct big_key_payload *payload = to_big_key_payload(prep->payload);
+
+	if (prep->datalen > BIG_KEY_FILE_THRESHOLD)
+		path_put(&payload->path);
+	kfree_sensitive(payload->data);
+}
+
+/*
+ * dispose of the links from a revoked keyring
+ * - called with the key sem write-locked
+ */
+void big_key_revoke(struct key *key)
+{
+	struct big_key_payload *payload = to_big_key_payload(key->payload);
+
+	/* clear the quota */
+	key_payload_reserve(key, 0);
+	if (key_is_positive(key) && payload->length > BIG_KEY_FILE_THRESHOLD)
+		vfs_truncate(&payload->path, 0);
+}
+
+/*
+ * dispose of the data dangling from the corpse of a big_key key
+ */
+void big_key_destroy(struct key *key)
+{
+	struct big_key_payload *payload = to_big_key_payload(key->payload);
+
+	if (payload->length > BIG_KEY_FILE_THRESHOLD) {
+		path_put(&payload->path);
+		payload->path.mnt = NULL;
+		payload->path.dentry = NULL;
+	}
+	kfree_sensitive(payload->data);
+	payload->data = NULL;
+}
+
+/*
+ * Update a big key
+ */
+int big_key_update(struct key *key, struct key_preparsed_payload *prep)
+{
+	int ret;
+
+	ret = key_payload_reserve(key, prep->datalen);
+	if (ret < 0)
+		return ret;
+
+	if (key_is_positive(key))
+		big_key_destroy(key);
+
+	return generic_key_instantiate(key, prep);
+}
+
+/*
+ * describe the big_key key
+ */
+void big_key_describe(const struct key *key, struct seq_file *m)
+{
+	struct big_key_payload *payload = to_big_key_payload(key->payload);
+
+	seq_puts(m, key->description);
+
+	if (key_is_positive(key))
+		seq_printf(m, ": %zu [%s]",
+			   payload->length,
+			   payload->length > BIG_KEY_FILE_THRESHOLD ? "file" : "buff");
+}
+
+/*
+ * read the key data
+ * - the key's semaphore is read-locked
+ */
+long big_key_read(const struct key *key, char *buffer, size_t buflen)
+{
+	struct big_key_payload *payload = to_big_key_payload(key->payload);
+	size_t datalen = payload->length;
+	long ret;
+
+	if (!buffer || buflen < datalen)
+		return datalen;
+
+	if (datalen > BIG_KEY_FILE_THRESHOLD) {
+		struct file *file;
+		u8 *buf, *enckey = payload->data;
+		size_t enclen = datalen + CHACHA20POLY1305_AUTHTAG_SIZE;
+		loff_t pos = 0;
+
+		buf = kvmalloc(enclen, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+
+		file = dentry_open(&payload->path, O_RDONLY, current_cred());
+		if (IS_ERR(file)) {
+			ret = PTR_ERR(file);
+			goto error;
+		}
+
+		/* read file to kernel and decrypt */
+		ret = kernel_read(file, buf, enclen, &pos);
+		if (ret != enclen) {
+			if (ret >= 0)
+				ret = -EIO;
+			goto err_fput;
+		}
+
+		ret = chacha20poly1305_decrypt(buf, buf, enclen, NULL, 0, 0,
+					       enckey) ? 0 : -EBADMSG;
+		if (unlikely(ret))
+			goto err_fput;
+
+		ret = datalen;
+
+		/* copy out decrypted data */
+		memcpy(buffer, buf, datalen);
+
+err_fput:
+		fput(file);
+error:
+		kvfree_sensitive(buf, enclen);
+	} else {
+		ret = datalen;
+		memcpy(buffer, payload->data, datalen);
+	}
+
+	return ret;
+}
+
+/*
+ * Register key type
+ */
+static int __init big_key_init(void)
+{
+	return register_key_type(&key_type_big_key);
+}
+
+late_initcall(big_key_init);

linux-7.2.3/security/keys/compat.c

@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* 32-bit compatibility syscall for 64-bit systems
+ *
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/syscalls.h>
+#include <linux/keyctl.h>
+#include <linux/compat.h>
+#include <linux/slab.h>
+#include "internal.h"
+
+/*
+ * The key control system call, 32-bit compatibility version for 64-bit archs
+ */
+COMPAT_SYSCALL_DEFINE5(keyctl, u32, option,
+		       u32, arg2, u32, arg3, u32, arg4, u32, arg5)
+{
+	switch (option) {
+	case KEYCTL_GET_KEYRING_ID:
+		return keyctl_get_keyring_ID(arg2, arg3);
+
+	case KEYCTL_JOIN_SESSION_KEYRING:
+		return keyctl_join_session_keyring(compat_ptr(arg2));
+
+	case KEYCTL_UPDATE:
+		return keyctl_update_key(arg2, compat_ptr(arg3), arg4);
+
+	case KEYCTL_REVOKE:
+		return keyctl_revoke_key(arg2);
+
+	case KEYCTL_DESCRIBE:
+		return keyctl_describe_key(arg2, compat_ptr(arg3), arg4);
+
+	case KEYCTL_CLEAR:
+		return keyctl_keyring_clear(arg2);
+
+	case KEYCTL_LINK:
+		return keyctl_keyring_link(arg2, arg3);
+
+	case KEYCTL_UNLINK:
+		return keyctl_keyring_unlink(arg2, arg3);
+
+	case KEYCTL_SEARCH:
+		return keyctl_keyring_search(arg2, compat_ptr(arg3),
+					     compat_ptr(arg4), arg5);
+
+	case KEYCTL_READ:
+		return keyctl_read_key(arg2, compat_ptr(arg3), arg4);
+
+	case KEYCTL_CHOWN:
+		return keyctl_chown_key(arg2, arg3, arg4);
+
+	case KEYCTL_SETPERM:
+		return keyctl_setperm_key(arg2, arg3);
+
+	case KEYCTL_INSTANTIATE:
+		return keyctl_instantiate_key(arg2, compat_ptr(arg3), arg4,
+					      arg5);
+
+	case KEYCTL_NEGATE:
+		return keyctl_negate_key(arg2, arg3, arg4);
+
+	case KEYCTL_SET_REQKEY_KEYRING:
+		return keyctl_set_reqkey_keyring(arg2);
+
+	case KEYCTL_SET_TIMEOUT:
+		return keyctl_set_timeout(arg2, arg3);
+
+	case KEYCTL_ASSUME_AUTHORITY:
+		return keyctl_assume_authority(arg2);
+
+	case KEYCTL_GET_SECURITY:
+		return keyctl_get_security(arg2, compat_ptr(arg3), arg4);
+
+	case KEYCTL_SESSION_TO_PARENT:
+		return keyctl_session_to_parent();
+
+	case KEYCTL_REJECT:
+		return keyctl_reject_key(arg2, arg3, arg4, arg5);
+
+	case KEYCTL_INSTANTIATE_IOV:
+		return keyctl_instantiate_key_iov(arg2, compat_ptr(arg3), arg4,
+						  arg5);
+
+	case KEYCTL_INVALIDATE:
+		return keyctl_invalidate_key(arg2);
+
+	case KEYCTL_GET_PERSISTENT:
+		return keyctl_get_persistent(arg2, arg3);
+
+	case KEYCTL_DH_COMPUTE:
+		return compat_keyctl_dh_compute(compat_ptr(arg2),
+						compat_ptr(arg3),
+						arg4, compat_ptr(arg5));
+
+	case KEYCTL_RESTRICT_KEYRING:
+		return keyctl_restrict_keyring(arg2, compat_ptr(arg3),
+					       compat_ptr(arg4));
+
+	case KEYCTL_PKEY_QUERY:
+		if (arg3 != 0)
+			return -EINVAL;
+		return keyctl_pkey_query(arg2,
+					 compat_ptr(arg4),
+					 compat_ptr(arg5));
+
+	case KEYCTL_PKEY_ENCRYPT:
+	case KEYCTL_PKEY_DECRYPT:
+	case KEYCTL_PKEY_SIGN:
+		return keyctl_pkey_e_d_s(option,
+					 compat_ptr(arg2), compat_ptr(arg3),
+					 compat_ptr(arg4), compat_ptr(arg5));
+
+	case KEYCTL_PKEY_VERIFY:
+		return keyctl_pkey_verify(compat_ptr(arg2), compat_ptr(arg3),
+					  compat_ptr(arg4), compat_ptr(arg5));
+
+	case KEYCTL_MOVE:
+		return keyctl_keyring_move(arg2, arg3, arg4, arg5);
+
+	case KEYCTL_CAPABILITIES:
+		return keyctl_capabilities(compat_ptr(arg2), arg3);
+
+	case KEYCTL_WATCH_KEY:
+		return keyctl_watch_key(arg2, arg3, arg4);
+
+	default:
+		return -EOPNOTSUPP;
+	}
+}

linux-7.2.3/security/keys/compat_dh.c

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* 32-bit compatibility syscall for 64-bit systems for DH operations
+ *
+ * Copyright (C) 2016 Stephan Mueller <smueller@chronox.de>
+ */
+
+#include <linux/uaccess.h>
+
+#include "internal.h"
+
+/*
+ * Perform the DH computation or DH based key derivation.
+ *
+ * If successful, 0 will be returned.
+ */
+long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
+			      char __user *buffer, size_t buflen,
+			      struct compat_keyctl_kdf_params __user *kdf)
+{
+	struct keyctl_kdf_params kdfcopy;
+	struct compat_keyctl_kdf_params compat_kdfcopy;
+
+	if (!kdf)
+		return __keyctl_dh_compute(params, buffer, buflen, NULL);
+
+	if (copy_from_user(&compat_kdfcopy, kdf, sizeof(compat_kdfcopy)) != 0)
+		return -EFAULT;
+
+	kdfcopy.hashname = compat_ptr(compat_kdfcopy.hashname);
+	kdfcopy.otherinfo = compat_ptr(compat_kdfcopy.otherinfo);
+	kdfcopy.otherinfolen = compat_kdfcopy.otherinfolen;
+	memcpy(kdfcopy.__spare, compat_kdfcopy.__spare,
+	       sizeof(kdfcopy.__spare));
+
+	return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy);
+}

linux-7.2.3/security/keys/dh.c

@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Crypto operations using stored keys
+ *
+ * Copyright (c) 2016, Intel Corporation
+ */
+
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/scatterlist.h>
+#include <linux/crypto.h>
+#include <crypto/hash.h>
+#include <crypto/kpp.h>
+#include <crypto/dh.h>
+#include <crypto/kdf_sp800108.h>
+#include <keys/user-type.h>
+#include "internal.h"
+
+static ssize_t dh_data_from_key(key_serial_t keyid, const void **data)
+{
+	struct key *key;
+	key_ref_t key_ref;
+	long status;
+	ssize_t ret;
+
+	key_ref = lookup_user_key(keyid, 0, KEY_NEED_READ);
+	if (IS_ERR(key_ref)) {
+		ret = -ENOKEY;
+		goto error;
+	}
+
+	key = key_ref_to_ptr(key_ref);
+
+	ret = -EOPNOTSUPP;
+	if (key->type == &key_type_user) {
+		down_read(&key->sem);
+		status = key_validate(key);
+		if (status == 0) {
+			const struct user_key_payload *payload;
+			uint8_t *duplicate;
+
+			payload = user_key_payload_locked(key);
+
+			duplicate = kmemdup(payload->data, payload->datalen,
+					    GFP_KERNEL);
+			if (duplicate) {
+				*data = duplicate;
+				ret = payload->datalen;
+			} else {
+				ret = -ENOMEM;
+			}
+		}
+		up_read(&key->sem);
+	}
+
+	key_put(key);
+error:
+	return ret;
+}
+
+static void dh_free_data(struct dh *dh)
+{
+	kfree_sensitive(dh->key);
+	kfree_sensitive(dh->p);
+	kfree_sensitive(dh->g);
+}
+
+static int kdf_alloc(struct crypto_shash **hash, char *hashname)
+{
+	struct crypto_shash *tfm;
+
+	/* allocate synchronous hash */
+	tfm = crypto_alloc_shash(hashname, 0, 0);
+	if (IS_ERR(tfm)) {
+		pr_info("could not allocate digest TFM handle %s\n", hashname);
+		return PTR_ERR(tfm);
+	}
+
+	if (crypto_shash_digestsize(tfm) == 0) {
+		crypto_free_shash(tfm);
+		return -EINVAL;
+	}
+
+	*hash = tfm;
+
+	return 0;
+}
+
+static void kdf_dealloc(struct crypto_shash *hash)
+{
+	if (hash)
+		crypto_free_shash(hash);
+}
+
+static int keyctl_dh_compute_kdf(struct crypto_shash *hash,
+				 char __user *buffer, size_t buflen,
+				 uint8_t *kbuf, size_t kbuflen)
+{
+	struct kvec kbuf_iov = { .iov_base = kbuf, .iov_len = kbuflen };
+	uint8_t *outbuf = NULL;
+	int ret;
+	size_t outbuf_len = roundup(buflen, crypto_shash_digestsize(hash));
+
+	outbuf = kmalloc(outbuf_len, GFP_KERNEL);
+	if (!outbuf) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	ret = crypto_kdf108_ctr_generate(hash, &kbuf_iov, 1, outbuf, outbuf_len);
+	if (ret)
+		goto err;
+
+	ret = buflen;
+	if (copy_to_user(buffer, outbuf, buflen) != 0)
+		ret = -EFAULT;
+
+err:
+	kfree_sensitive(outbuf);
+	return ret;
+}
+
+long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
+			 char __user *buffer, size_t buflen,
+			 struct keyctl_kdf_params *kdfcopy)
+{
+	long ret;
+	ssize_t dlen;
+	int secretlen;
+	int outlen;
+	struct keyctl_dh_params pcopy;
+	struct dh dh_inputs;
+	struct scatterlist outsg;
+	DECLARE_CRYPTO_WAIT(compl);
+	struct crypto_kpp *tfm;
+	struct kpp_request *req;
+	uint8_t *secret;
+	uint8_t *outbuf;
+	struct crypto_shash *hash = NULL;
+
+	if (!params || (!buffer && buflen)) {
+		ret = -EINVAL;
+		goto out1;
+	}
+	if (copy_from_user(&pcopy, params, sizeof(pcopy)) != 0) {
+		ret = -EFAULT;
+		goto out1;
+	}
+
+	if (kdfcopy) {
+		char *hashname;
+
+		if (memchr_inv(kdfcopy->__spare, 0, sizeof(kdfcopy->__spare))) {
+			ret = -EINVAL;
+			goto out1;
+		}
+
+		if (buflen > KEYCTL_KDF_MAX_OUTPUT_LEN ||
+		    kdfcopy->otherinfolen > KEYCTL_KDF_MAX_OI_LEN) {
+			ret = -EMSGSIZE;
+			goto out1;
+		}
+
+		/* get KDF name string */
+		hashname = strndup_user(kdfcopy->hashname, CRYPTO_MAX_ALG_NAME);
+		if (IS_ERR(hashname)) {
+			ret = PTR_ERR(hashname);
+			goto out1;
+		}
+
+		/* allocate KDF from the kernel crypto API */
+		ret = kdf_alloc(&hash, hashname);
+		kfree(hashname);
+		if (ret)
+			goto out1;
+	}
+
+	memset(&dh_inputs, 0, sizeof(dh_inputs));
+
+	dlen = dh_data_from_key(pcopy.prime, &dh_inputs.p);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out1;
+	}
+	dh_inputs.p_size = dlen;
+
+	dlen = dh_data_from_key(pcopy.base, &dh_inputs.g);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out2;
+	}
+	dh_inputs.g_size = dlen;
+
+	dlen = dh_data_from_key(pcopy.private, &dh_inputs.key);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out2;
+	}
+	dh_inputs.key_size = dlen;
+
+	secretlen = crypto_dh_key_len(&dh_inputs);
+	secret = kmalloc(secretlen, GFP_KERNEL);
+	if (!secret) {
+		ret = -ENOMEM;
+		goto out2;
+	}
+	ret = crypto_dh_encode_key(secret, secretlen, &dh_inputs);
+	if (ret)
+		goto out3;
+
+	tfm = crypto_alloc_kpp("dh", 0, 0);
+	if (IS_ERR(tfm)) {
+		ret = PTR_ERR(tfm);
+		goto out3;
+	}
+
+	ret = crypto_kpp_set_secret(tfm, secret, secretlen);
+	if (ret)
+		goto out4;
+
+	outlen = crypto_kpp_maxsize(tfm);
+
+	if (!kdfcopy) {
+		/*
+		 * When not using a KDF, buflen 0 is used to read the
+		 * required buffer length
+		 */
+		if (buflen == 0) {
+			ret = outlen;
+			goto out4;
+		} else if (outlen > buflen) {
+			ret = -EOVERFLOW;
+			goto out4;
+		}
+	}
+
+	outbuf = kzalloc(kdfcopy ? (outlen + kdfcopy->otherinfolen) : outlen,
+			 GFP_KERNEL);
+	if (!outbuf) {
+		ret = -ENOMEM;
+		goto out4;
+	}
+
+	sg_init_one(&outsg, outbuf, outlen);
+
+	req = kpp_request_alloc(tfm, GFP_KERNEL);
+	if (!req) {
+		ret = -ENOMEM;
+		goto out5;
+	}
+
+	kpp_request_set_input(req, NULL, 0);
+	kpp_request_set_output(req, &outsg, outlen);
+	kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+				 CRYPTO_TFM_REQ_MAY_SLEEP,
+				 crypto_req_done, &compl);
+
+	/*
+	 * For DH, generate_public_key and generate_shared_secret are
+	 * the same calculation
+	 */
+	ret = crypto_kpp_generate_public_key(req);
+	ret = crypto_wait_req(ret, &compl);
+	if (ret)
+		goto out6;
+
+	if (kdfcopy) {
+		/*
+		 * Concatenate SP800-56A otherinfo past DH shared secret -- the
+		 * input to the KDF is (DH shared secret || otherinfo)
+		 */
+		if (copy_from_user(outbuf + req->dst_len, kdfcopy->otherinfo,
+				   kdfcopy->otherinfolen) != 0) {
+			ret = -EFAULT;
+			goto out6;
+		}
+
+		ret = keyctl_dh_compute_kdf(hash, buffer, buflen, outbuf,
+					    req->dst_len + kdfcopy->otherinfolen);
+	} else if (copy_to_user(buffer, outbuf, req->dst_len) == 0) {
+		ret = req->dst_len;
+	} else {
+		ret = -EFAULT;
+	}
+
+out6:
+	kpp_request_free(req);
+out5:
+	kfree_sensitive(outbuf);
+out4:
+	crypto_free_kpp(tfm);
+out3:
+	kfree_sensitive(secret);
+out2:
+	dh_free_data(&dh_inputs);
+out1:
+	kdf_dealloc(hash);
+	return ret;
+}
+
+long keyctl_dh_compute(struct keyctl_dh_params __user *params,
+		       char __user *buffer, size_t buflen,
+		       struct keyctl_kdf_params __user *kdf)
+{
+	struct keyctl_kdf_params kdfcopy;
+
+	if (!kdf)
+		return __keyctl_dh_compute(params, buffer, buflen, NULL);
+
+	if (copy_from_user(&kdfcopy, kdf, sizeof(kdfcopy)) != 0)
+		return -EFAULT;
+
+	return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy);
+}

linux-7.2.3/security/keys/encrypted-keys/Makefile

@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for encrypted keys
+#
+
+obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys.o
+
+encrypted-keys-y := encrypted.o ecryptfs_format.o
+masterkey-$(CONFIG_TRUSTED_KEYS) := masterkey_trusted.o
+masterkey-$(CONFIG_TRUSTED_KEYS)-$(CONFIG_ENCRYPTED_KEYS) := masterkey_trusted.o
+encrypted-keys-y += $(masterkey-y) $(masterkey-m-m)

linux-7.2.3/security/keys/encrypted-keys/ecryptfs_format.c

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ecryptfs_format.c: helper functions for the encrypted key type
+ *
+ * Copyright (C) 2006 International Business Machines Corp.
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ *                    TORSEC group -- https://security.polito.it
+ *
+ * Authors:
+ * Michael A. Halcrow <mahalcro@us.ibm.com>
+ * Tyler Hicks <tyhicks@ou.edu>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ */
+
+#include <linux/export.h>
+#include <linux/string.h>
+#include "ecryptfs_format.h"
+
+u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok)
+{
+	return auth_tok->token.password.session_key_encryption_key;
+}
+EXPORT_SYMBOL(ecryptfs_get_auth_tok_key);
+
+/*
+ * ecryptfs_get_versions()
+ *
+ * Source code taken from the software 'ecryptfs-utils' version 83.
+ *
+ */
+void ecryptfs_get_versions(int *major, int *minor, int *file_version)
+{
+	*major = ECRYPTFS_VERSION_MAJOR;
+	*minor = ECRYPTFS_VERSION_MINOR;
+	if (file_version)
+		*file_version = ECRYPTFS_SUPPORTED_FILE_VERSION;
+}
+EXPORT_SYMBOL(ecryptfs_get_versions);
+
+/*
+ * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure
+ *
+ * Fill the ecryptfs_auth_tok structure with required ecryptfs data.
+ * The source code is inspired to the original function generate_payload()
+ * shipped with the software 'ecryptfs-utils' version 83.
+ *
+ */
+int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok,
+			   const char *key_desc)
+{
+	int major, minor;
+
+	ecryptfs_get_versions(&major, &minor, NULL);
+	auth_tok->version = (((uint16_t)(major << 8) & 0xFF00)
+			     | ((uint16_t)minor & 0x00FF));
+	auth_tok->token_type = ECRYPTFS_PASSWORD;
+	strscpy_pad(auth_tok->token.password.signature, key_desc);
+	auth_tok->token.password.session_key_encryption_key_bytes =
+		ECRYPTFS_MAX_KEY_BYTES;
+	/*
+	 * Removed auth_tok->token.password.salt and
+	 * auth_tok->token.password.session_key_encryption_key
+	 * initialization from the original code
+	 */
+	/* TODO: Make the hash parameterizable via policy */
+	auth_tok->token.password.flags |=
+		ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET;
+	/* The kernel code will encrypt the session key. */
+	auth_tok->session_key.encrypted_key[0] = 0;
+	auth_tok->session_key.encrypted_key_size = 0;
+	/* Default; subject to change by kernel eCryptfs */
+	auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512;
+	auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD);
+	return 0;
+}
+EXPORT_SYMBOL(ecryptfs_fill_auth_tok);

linux-7.2.3/security/keys/encrypted-keys/ecryptfs_format.h

@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * ecryptfs_format.h: helper functions for the encrypted key type
+ *
+ * Copyright (C) 2006 International Business Machines Corp.
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ *                    TORSEC group -- https://security.polito.it
+ *
+ * Authors:
+ * Michael A. Halcrow <mahalcro@us.ibm.com>
+ * Tyler Hicks <tyhicks@ou.edu>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ */
+
+#ifndef __KEYS_ECRYPTFS_H
+#define __KEYS_ECRYPTFS_H
+
+#include <linux/ecryptfs.h>
+
+#define PGP_DIGEST_ALGO_SHA512   10
+
+u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok);
+void ecryptfs_get_versions(int *major, int *minor, int *file_version);
+int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok,
+			   const char *key_desc);
+
+#endif /* __KEYS_ECRYPTFS_H */

linux-7.2.3/security/keys/encrypted-keys/encrypted.h

@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ENCRYPTED_KEY_H
+#define __ENCRYPTED_KEY_H
+
+#define ENCRYPTED_DEBUG 0
+#if defined(CONFIG_TRUSTED_KEYS) || \
+  (defined(CONFIG_TRUSTED_KEYS_MODULE) && defined(CONFIG_ENCRYPTED_KEYS_MODULE))
+extern struct key *request_trusted_key(const char *trusted_desc,
+				       const u8 **master_key, size_t *master_keylen);
+#else
+static inline struct key *request_trusted_key(const char *trusted_desc,
+					      const u8 **master_key,
+					      size_t *master_keylen)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+#endif
+
+#if ENCRYPTED_DEBUG
+static inline void dump_master_key(const u8 *master_key, size_t master_keylen)
+{
+	print_hex_dump(KERN_ERR, "master key: ", DUMP_PREFIX_NONE, 32, 1,
+		       master_key, master_keylen, 0);
+}
+
+static inline void dump_decrypted_data(struct encrypted_key_payload *epayload)
+{
+	print_hex_dump(KERN_ERR, "decrypted data: ", DUMP_PREFIX_NONE, 32, 1,
+		       epayload->decrypted_data,
+		       epayload->decrypted_datalen, 0);
+}
+
+static inline void dump_encrypted_data(struct encrypted_key_payload *epayload,
+				       unsigned int encrypted_datalen)
+{
+	print_hex_dump(KERN_ERR, "encrypted data: ", DUMP_PREFIX_NONE, 32, 1,
+		       epayload->encrypted_data, encrypted_datalen, 0);
+}
+
+static inline void dump_hmac(const char *str, const u8 *digest,
+			     unsigned int hmac_size)
+{
+	if (str)
+		pr_info("encrypted_key: %s", str);
+	print_hex_dump(KERN_ERR, "hmac: ", DUMP_PREFIX_NONE, 32, 1, digest,
+		       hmac_size, 0);
+}
+#else
+static inline void dump_master_key(const u8 *master_key, size_t master_keylen)
+{
+}
+
+static inline void dump_decrypted_data(struct encrypted_key_payload *epayload)
+{
+}
+
+static inline void dump_encrypted_data(struct encrypted_key_payload *epayload,
+				       unsigned int encrypted_datalen)
+{
+}
+
+static inline void dump_hmac(const char *str, const u8 *digest,
+			     unsigned int hmac_size)
+{
+}
+#endif
+#endif

linux-7.2.3/security/keys/encrypted-keys/masterkey_trusted.c

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2010 IBM Corporation
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ *                    TORSEC group -- https://security.polito.it
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ *
+ * See Documentation/security/keys/trusted-encrypted.rst
+ */
+
+#include <linux/uaccess.h>
+#include <linux/err.h>
+#include <keys/trusted-type.h>
+#include <keys/encrypted-type.h>
+#include "encrypted.h"
+
+/*
+ * request_trusted_key - request the trusted key
+ *
+ * Trusted keys are sealed to PCRs and other metadata. Although userspace
+ * manages both trusted/encrypted key-types, like the encrypted key type
+ * data, trusted key type data is not visible decrypted from userspace.
+ */
+struct key *request_trusted_key(const char *trusted_desc,
+				const u8 **master_key, size_t *master_keylen)
+{
+	struct trusted_key_payload *tpayload;
+	struct key *tkey;
+
+	tkey = request_key(&key_type_trusted, trusted_desc, NULL);
+	if (IS_ERR(tkey))
+		goto error;
+
+	down_read(&tkey->sem);
+	tpayload = tkey->payload.data[0];
+	*master_key = tpayload->key;
+	*master_keylen = tpayload->key_len;
+error:
+	return tkey;
+}

linux-7.2.3/security/keys/gc.c

@@ -0,0 +1,374 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Key garbage collector
+ *
+ * Copyright (C) 2009-2011 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <keys/keyring-type.h>
+#include "internal.h"
+
+/*
+ * Delay between key revocation/expiry in seconds
+ */
+unsigned key_gc_delay = 5 * 60;
+
+/*
+ * Reaper for unused keys.
+ */
+static void key_garbage_collector(struct work_struct *work);
+DECLARE_WORK(key_gc_work, key_garbage_collector);
+
+/*
+ * Reaper for links from keyrings to dead keys.
+ */
+static void key_gc_timer_func(struct timer_list *);
+static DEFINE_TIMER(key_gc_timer, key_gc_timer_func);
+
+static time64_t key_gc_next_run = TIME64_MAX;
+static struct key_type *key_gc_dead_keytype;
+
+static unsigned long key_gc_flags;
+#define KEY_GC_KEY_EXPIRED	0	/* A key expired and needs unlinking */
+#define KEY_GC_REAP_KEYTYPE	1	/* A keytype is being unregistered */
+#define KEY_GC_REAPING_KEYTYPE	2	/* Cleared when keytype reaped */
+
+
+/*
+ * Any key whose type gets unregistered will be re-typed to this if it can't be
+ * immediately unlinked.
+ */
+struct key_type key_type_dead = {
+	.name = ".dead",
+};
+
+/*
+ * Schedule a garbage collection run.
+ * - time precision isn't particularly important
+ */
+void key_schedule_gc(time64_t gc_at)
+{
+	unsigned long expires;
+	time64_t now = ktime_get_real_seconds();
+
+	kenter("%lld", gc_at - now);
+
+	if (gc_at <= now || test_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags)) {
+		kdebug("IMMEDIATE");
+		schedule_work(&key_gc_work);
+	} else if (gc_at < key_gc_next_run) {
+		kdebug("DEFERRED");
+		key_gc_next_run = gc_at;
+		expires = jiffies + (gc_at - now) * HZ;
+		mod_timer(&key_gc_timer, expires);
+	}
+}
+
+/*
+ * Set the expiration time on a key.
+ */
+void key_set_expiry(struct key *key, time64_t expiry)
+{
+	key->expiry = expiry;
+	if (expiry != TIME64_MAX) {
+		if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
+			expiry += key_gc_delay;
+		key_schedule_gc(expiry);
+	}
+}
+
+/*
+ * Schedule a dead links collection run.
+ */
+void key_schedule_gc_links(void)
+{
+	set_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags);
+	schedule_work(&key_gc_work);
+}
+
+/*
+ * Some key's cleanup time was met after it expired, so we need to get the
+ * reaper to go through a cycle finding expired keys.
+ */
+static void key_gc_timer_func(struct timer_list *unused)
+{
+	kenter("");
+	key_gc_next_run = TIME64_MAX;
+	key_schedule_gc_links();
+}
+
+/*
+ * Reap keys of dead type.
+ *
+ * We use three flags to make sure we see three complete cycles of the garbage
+ * collector: the first to mark keys of that type as being dead, the second to
+ * collect dead links and the third to clean up the dead keys.  We have to be
+ * careful as there may already be a cycle in progress.
+ *
+ * The caller must be holding key_types_sem.
+ */
+void key_gc_keytype(struct key_type *ktype)
+{
+	kenter("%s", ktype->name);
+
+	key_gc_dead_keytype = ktype;
+	set_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags);
+	smp_mb();
+	set_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags);
+
+	kdebug("schedule");
+	schedule_work(&key_gc_work);
+
+	kdebug("sleep");
+	wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE,
+		    TASK_UNINTERRUPTIBLE);
+
+	key_gc_dead_keytype = NULL;
+	kleave("");
+}
+
+/*
+ * Garbage collect a list of unreferenced, detached keys
+ */
+static noinline void key_gc_unused_keys(struct list_head *keys)
+{
+	while (!list_empty(keys)) {
+		struct key *key =
+			list_entry(keys->next, struct key, graveyard_link);
+		short state = key->state;
+
+		list_del(&key->graveyard_link);
+
+		kdebug("- %u", key->serial);
+		key_check(key);
+
+#ifdef CONFIG_KEY_NOTIFICATIONS
+		remove_watch_list(key->watchers, key->serial);
+		key->watchers = NULL;
+#endif
+
+		/* Throw away the key data if the key is instantiated */
+		if (state == KEY_IS_POSITIVE && key->type->destroy)
+			key->type->destroy(key);
+
+		security_key_free(key);
+
+		atomic_dec(&key->user->nkeys);
+		if (state != KEY_IS_UNINSTANTIATED)
+			atomic_dec(&key->user->nikeys);
+
+		key_user_put(key->user);
+		key_put_tag(key->domain_tag);
+		kfree(key->description);
+
+		memzero_explicit(key, sizeof(*key));
+		kmem_cache_free(key_jar, key);
+	}
+}
+
+/*
+ * Garbage collector for unused keys.
+ *
+ * This is done in process context so that we don't have to disable interrupts
+ * all over the place.  key_put() schedules this rather than trying to do the
+ * cleanup itself, which means key_put() doesn't have to sleep.
+ */
+static void key_garbage_collector(struct work_struct *work)
+{
+	static LIST_HEAD(graveyard);
+	static u8 gc_state;		/* Internal persistent state */
+#define KEY_GC_REAP_AGAIN	0x01	/* - Need another cycle */
+#define KEY_GC_REAPING_LINKS	0x02	/* - We need to reap links */
+#define KEY_GC_REAPING_DEAD_1	0x10	/* - We need to mark dead keys */
+#define KEY_GC_REAPING_DEAD_2	0x20	/* - We need to reap dead key links */
+#define KEY_GC_REAPING_DEAD_3	0x40	/* - We need to reap dead keys */
+#define KEY_GC_FOUND_DEAD_KEY	0x80	/* - We found at least one dead key */
+
+	struct rb_node *cursor;
+	struct key *key;
+	time64_t new_timer, limit, expiry;
+
+	kenter("[%lx,%x]", key_gc_flags, gc_state);
+
+	limit = ktime_get_real_seconds();
+
+	/* Work out what we're going to be doing in this pass */
+	gc_state &= KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2;
+	gc_state <<= 1;
+	if (test_and_clear_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags))
+		gc_state |= KEY_GC_REAPING_LINKS;
+
+	if (test_and_clear_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags))
+		gc_state |= KEY_GC_REAPING_DEAD_1;
+	kdebug("new pass %x", gc_state);
+
+	new_timer = TIME64_MAX;
+
+	/* As only this function is permitted to remove things from the key
+	 * serial tree, if cursor is non-NULL then it will always point to a
+	 * valid node in the tree - even if lock got dropped.
+	 */
+	spin_lock(&key_serial_lock);
+	cursor = rb_first(&key_serial_tree);
+
+continue_scanning:
+	while (cursor) {
+		key = rb_entry(cursor, struct key, serial_node);
+		cursor = rb_next(cursor);
+
+		if (!test_bit_acquire(KEY_FLAG_USER_ALIVE, &key->flags)) {
+			/* Clobber key->user after final put seen. */
+			goto found_unreferenced_key;
+		}
+
+		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_1)) {
+			if (key->type == key_gc_dead_keytype) {
+				gc_state |= KEY_GC_FOUND_DEAD_KEY;
+				set_bit(KEY_FLAG_DEAD, &key->flags);
+				key->perm = 0;
+				goto skip_dead_key;
+			} else if (key->type == &key_type_keyring &&
+				   key->restrict_link) {
+				goto found_restricted_keyring;
+			}
+		}
+
+		expiry = key->expiry;
+		if (expiry != TIME64_MAX) {
+			if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
+				expiry += key_gc_delay;
+			if (expiry > limit && expiry < new_timer) {
+				kdebug("will expire %x in %lld",
+				       key_serial(key), key->expiry - limit);
+				new_timer = key->expiry;
+			}
+		}
+
+		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2))
+			if (key->type == key_gc_dead_keytype)
+				gc_state |= KEY_GC_FOUND_DEAD_KEY;
+
+		if ((gc_state & KEY_GC_REAPING_LINKS) ||
+		    unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) {
+			if (key->type == &key_type_keyring)
+				goto found_keyring;
+		}
+
+		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3))
+			if (key->type == key_gc_dead_keytype)
+				goto destroy_dead_key;
+
+	skip_dead_key:
+		if (spin_is_contended(&key_serial_lock) || need_resched())
+			goto contended;
+	}
+
+contended:
+	spin_unlock(&key_serial_lock);
+
+maybe_resched:
+	if (cursor) {
+		cond_resched();
+		spin_lock(&key_serial_lock);
+		goto continue_scanning;
+	}
+
+	/* We've completed the pass.  Set the timer if we need to and queue a
+	 * new cycle if necessary.  We keep executing cycles until we find one
+	 * where we didn't reap any keys.
+	 */
+	kdebug("pass complete");
+
+	if (new_timer != TIME64_MAX) {
+		new_timer += key_gc_delay;
+		key_schedule_gc(new_timer);
+	}
+
+	if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2) ||
+	    !list_empty(&graveyard)) {
+		/* Make sure that all pending keyring payload destructions are
+		 * fulfilled and that people aren't now looking at dead or
+		 * dying keys that they don't have a reference upon or a link
+		 * to.
+		 */
+		kdebug("gc sync");
+		synchronize_rcu();
+	}
+
+	if (!list_empty(&graveyard)) {
+		kdebug("gc keys");
+		key_gc_unused_keys(&graveyard);
+	}
+
+	if (unlikely(gc_state & (KEY_GC_REAPING_DEAD_1 |
+				 KEY_GC_REAPING_DEAD_2))) {
+		if (!(gc_state & KEY_GC_FOUND_DEAD_KEY)) {
+			/* No remaining dead keys: short circuit the remaining
+			 * keytype reap cycles.
+			 */
+			kdebug("dead short");
+			gc_state &= ~(KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2);
+			gc_state |= KEY_GC_REAPING_DEAD_3;
+		} else {
+			gc_state |= KEY_GC_REAP_AGAIN;
+		}
+	}
+
+	if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) {
+		kdebug("dead wake");
+		smp_mb();
+		clear_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags);
+		wake_up_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE);
+	}
+
+	if (gc_state & KEY_GC_REAP_AGAIN)
+		schedule_work(&key_gc_work);
+	kleave(" [end %x]", gc_state);
+	return;
+
+	/* We found an unreferenced key - once we've removed it from the tree,
+	 * we can safely drop the lock.
+	 */
+found_unreferenced_key:
+	kdebug("unrefd key %d", key->serial);
+	rb_erase(&key->serial_node, &key_serial_tree);
+	spin_unlock(&key_serial_lock);
+
+	list_add_tail(&key->graveyard_link, &graveyard);
+	gc_state |= KEY_GC_REAP_AGAIN;
+	goto maybe_resched;
+
+	/* We found a restricted keyring and need to update the restriction if
+	 * it is associated with the dead key type.
+	 */
+found_restricted_keyring:
+	spin_unlock(&key_serial_lock);
+	keyring_restriction_gc(key, key_gc_dead_keytype);
+	goto maybe_resched;
+
+	/* We found a keyring and we need to check the payload for links to
+	 * dead or expired keys.  We don't flag another reap immediately as we
+	 * have to wait for the old payload to be destroyed by RCU before we
+	 * can reap the keys to which it refers.
+	 */
+found_keyring:
+	spin_unlock(&key_serial_lock);
+	keyring_gc(key, limit);
+	goto maybe_resched;
+
+	/* We found a dead key that is still referenced.  Reset its type and
+	 * destroy its payload with its semaphore held.
+	 */
+destroy_dead_key:
+	spin_unlock(&key_serial_lock);
+	kdebug("destroy key %d", key->serial);
+	down_write(&key->sem);
+	key->type = &key_type_dead;
+	if (key_gc_dead_keytype->destroy)
+		key_gc_dead_keytype->destroy(key);
+	memset(&key->payload, KEY_DESTROY, sizeof(key->payload));
+	up_write(&key->sem);
+	goto maybe_resched;
+}

linux-7.2.3/security/keys/internal.h

@@ -0,0 +1,378 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Authentication token and access key management internal defs
+ *
+ * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#ifndef _INTERNAL_H
+#define _INTERNAL_H
+
+#include <linux/sched.h>
+#include <linux/wait_bit.h>
+#include <linux/cred.h>
+#include <linux/key-type.h>
+#include <linux/task_work.h>
+#include <linux/keyctl.h>
+#include <linux/refcount.h>
+#include <linux/watch_queue.h>
+#include <linux/compat.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+
+struct iovec;
+
+#ifdef __KDEBUG
+#define kenter(FMT, ...) \
+	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
+#else
+#define kenter(FMT, ...) \
+	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
+#endif
+
+extern struct key_type key_type_dead;
+extern struct key_type key_type_user;
+extern struct key_type key_type_logon;
+
+/*****************************************************************************/
+/*
+ * Keep track of keys for a user.
+ *
+ * This needs to be separate to user_struct to avoid a refcount-loop
+ * (user_struct pins some keyrings which pin this struct).
+ *
+ * We also keep track of keys under request from userspace for this UID here.
+ */
+struct key_user {
+	struct rb_node		node;
+	struct mutex		cons_lock;	/* construction initiation lock */
+	spinlock_t		lock;
+	refcount_t		usage;		/* for accessing qnkeys & qnbytes */
+	atomic_t		nkeys;		/* number of keys */
+	atomic_t		nikeys;		/* number of instantiated keys */
+	kuid_t			uid;
+	int			qnkeys;		/* number of keys allocated to this user */
+	int			qnbytes;	/* number of bytes allocated to this user */
+};
+
+extern struct rb_root	key_user_tree;
+extern spinlock_t	key_user_lock;
+extern struct key_user	root_key_user;
+
+extern struct key_user *key_user_lookup(kuid_t uid);
+extern void key_user_put(struct key_user *user);
+
+/*
+ * Key quota limits.
+ * - root has its own separate limits to everyone else
+ */
+extern unsigned key_quota_root_maxkeys;
+extern unsigned key_quota_root_maxbytes;
+extern unsigned key_quota_maxkeys;
+extern unsigned key_quota_maxbytes;
+
+#define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
+
+
+extern struct kmem_cache *key_jar;
+extern struct rb_root key_serial_tree;
+extern spinlock_t key_serial_lock;
+extern struct mutex key_construction_mutex;
+extern wait_queue_head_t request_key_conswq;
+
+extern void key_set_index_key(struct keyring_index_key *index_key);
+extern struct key_type *key_type_lookup(const char *type);
+extern void key_type_put(struct key_type *ktype);
+
+extern int __key_link_lock(struct key *keyring,
+			   const struct keyring_index_key *index_key);
+extern int __key_move_lock(struct key *l_keyring, struct key *u_keyring,
+			   const struct keyring_index_key *index_key);
+extern int __key_link_begin(struct key *keyring,
+			    const struct keyring_index_key *index_key,
+			    struct assoc_array_edit **_edit);
+extern int __key_link_check_live_key(struct key *keyring, struct key *key);
+extern void __key_link(struct key *keyring, struct key *key,
+		       struct assoc_array_edit **_edit);
+extern void __key_link_end(struct key *keyring,
+			   const struct keyring_index_key *index_key,
+			   struct assoc_array_edit *edit);
+
+extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
+				    const struct keyring_index_key *index_key);
+
+struct keyring_search_context {
+	struct keyring_index_key index_key;
+	const struct cred	*cred;
+	struct key_match_data	match_data;
+	unsigned		flags;
+#define KEYRING_SEARCH_NO_STATE_CHECK	0x0001	/* Skip state checks */
+#define KEYRING_SEARCH_DO_STATE_CHECK	0x0002	/* Override NO_STATE_CHECK */
+#define KEYRING_SEARCH_NO_UPDATE_TIME	0x0004	/* Don't update times */
+#define KEYRING_SEARCH_NO_CHECK_PERM	0x0008	/* Don't check permissions */
+#define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0010	/* Give an error on excessive depth */
+#define KEYRING_SEARCH_SKIP_EXPIRED	0x0020	/* Ignore expired keys (intention to replace) */
+#define KEYRING_SEARCH_RECURSE		0x0040	/* Search child keyrings also */
+
+	int (*iterator)(const void *object, void *iterator_data);
+
+	/* Internal stuff */
+	int			skipped_ret;
+	bool			possessed;
+	key_ref_t		result;
+	time64_t		now;
+};
+
+extern bool key_default_cmp(const struct key *key,
+			    const struct key_match_data *match_data);
+extern key_ref_t keyring_search_rcu(key_ref_t keyring_ref,
+				    struct keyring_search_context *ctx);
+
+extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx);
+extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx);
+
+extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
+
+extern int look_up_user_keyrings(struct key **, struct key **);
+extern struct key *get_user_session_keyring_rcu(const struct cred *);
+extern int install_thread_keyring_to_cred(struct cred *);
+extern int install_process_keyring_to_cred(struct cred *);
+extern int install_session_keyring_to_cred(struct cred *, struct key *);
+
+extern struct key *request_key_and_link(struct key_type *type,
+					const char *description,
+					struct key_tag *domain_tag,
+					const void *callout_info,
+					size_t callout_len,
+					void *aux,
+					struct key *dest_keyring,
+					unsigned long flags);
+
+extern bool lookup_user_key_possessed(const struct key *key,
+				      const struct key_match_data *match_data);
+
+extern long join_session_keyring(const char *name);
+extern void key_change_session_keyring(struct callback_head *twork);
+
+extern struct work_struct key_gc_work;
+extern unsigned key_gc_delay;
+extern void keyring_gc(struct key *keyring, time64_t limit);
+extern void keyring_restriction_gc(struct key *keyring,
+				   struct key_type *dead_type);
+void key_set_expiry(struct key *key, time64_t expiry);
+extern void key_schedule_gc(time64_t gc_at);
+extern void key_schedule_gc_links(void);
+extern void key_gc_keytype(struct key_type *ktype);
+
+extern int key_task_permission(const key_ref_t key_ref,
+			       const struct cred *cred,
+			       enum key_need_perm need_perm);
+
+static inline void notify_key(struct key *key,
+			      enum key_notification_subtype subtype, u32 aux)
+{
+#ifdef CONFIG_KEY_NOTIFICATIONS
+	struct key_notification n = {
+		.watch.type	= WATCH_TYPE_KEY_NOTIFY,
+		.watch.subtype	= subtype,
+		.watch.info	= watch_sizeof(n),
+		.key_id		= key_serial(key),
+		.aux		= aux,
+	};
+
+	post_watch_notification(key->watchers, &n.watch, current_cred(),
+				n.key_id);
+#endif
+}
+
+/*
+ * Check to see whether permission is granted to use a key in the desired way.
+ */
+static inline int key_permission(const key_ref_t key_ref,
+				 enum key_need_perm need_perm)
+{
+	return key_task_permission(key_ref, current_cred(), need_perm);
+}
+
+extern struct key_type key_type_request_key_auth;
+extern struct key *request_key_auth_new(struct key *target,
+					const char *op,
+					const void *callout_info,
+					size_t callout_len,
+					struct key *dest_keyring);
+struct request_key_auth *request_key_auth_get(struct key *authkey);
+void request_key_auth_put(struct request_key_auth *rka);
+
+extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
+
+/*
+ * Determine whether a key is dead.
+ */
+static inline bool key_is_dead(const struct key *key, time64_t limit)
+{
+	time64_t expiry = key->expiry;
+
+	if (expiry != TIME64_MAX) {
+		if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
+			expiry += key_gc_delay;
+		if (expiry <= limit)
+			return true;
+	}
+
+	return
+		key->flags & ((1 << KEY_FLAG_DEAD) |
+			      (1 << KEY_FLAG_INVALIDATED)) ||
+		key->domain_tag->removed;
+}
+
+/*
+ * keyctl() functions
+ */
+extern long keyctl_get_keyring_ID(key_serial_t, int);
+extern long keyctl_join_session_keyring(const char __user *);
+extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
+extern long keyctl_revoke_key(key_serial_t);
+extern long keyctl_keyring_clear(key_serial_t);
+extern long keyctl_keyring_link(key_serial_t, key_serial_t);
+extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
+extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
+extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
+extern long keyctl_keyring_search(key_serial_t, const char __user *,
+				  const char __user *, key_serial_t);
+extern long keyctl_read_key(key_serial_t, char __user *, size_t);
+extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
+extern long keyctl_setperm_key(key_serial_t, key_perm_t);
+extern long keyctl_instantiate_key(key_serial_t, const void __user *,
+				   size_t, key_serial_t);
+extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
+extern long keyctl_set_reqkey_keyring(int);
+extern long keyctl_set_timeout(key_serial_t, unsigned);
+extern long keyctl_assume_authority(key_serial_t);
+extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
+				size_t buflen);
+extern long keyctl_session_to_parent(void);
+extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
+extern long keyctl_instantiate_key_iov(key_serial_t,
+				       const struct iovec __user *,
+				       unsigned, key_serial_t);
+extern long keyctl_invalidate_key(key_serial_t);
+extern long keyctl_restrict_keyring(key_serial_t id,
+				    const char __user *_type,
+				    const char __user *_restriction);
+#ifdef CONFIG_PERSISTENT_KEYRINGS
+extern long keyctl_get_persistent(uid_t, key_serial_t);
+extern unsigned persistent_keyring_expiry;
+#else
+static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+#ifdef CONFIG_KEY_DH_OPERATIONS
+extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
+			      size_t, struct keyctl_kdf_params __user *);
+extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
+				size_t, struct keyctl_kdf_params *);
+#ifdef CONFIG_COMPAT
+extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
+				char __user *buffer, size_t buflen,
+				struct compat_keyctl_kdf_params __user *kdf);
+#endif
+#define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
+#define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
+#else
+static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
+				     char __user *buffer, size_t buflen,
+				     struct keyctl_kdf_params __user *kdf)
+{
+	return -EOPNOTSUPP;
+}
+
+#ifdef CONFIG_COMPAT
+static inline long compat_keyctl_dh_compute(
+				struct keyctl_dh_params __user *params,
+				char __user *buffer, size_t buflen,
+				struct keyctl_kdf_params __user *kdf)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+#endif
+
+#ifdef CONFIG_ASYMMETRIC_KEY_TYPE
+extern long keyctl_pkey_query(key_serial_t,
+			      const char __user *,
+			      struct keyctl_pkey_query __user *);
+
+extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
+			       const char __user *,
+			       const void __user *, const void __user *);
+
+extern long keyctl_pkey_e_d_s(int,
+			      const struct keyctl_pkey_params __user *,
+			      const char __user *,
+			      const void __user *, void __user *);
+#else
+static inline long keyctl_pkey_query(key_serial_t id,
+				     const char __user *_info,
+				     struct keyctl_pkey_query __user *_res)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
+				      const char __user *_info,
+				      const void __user *_in,
+				      const void __user *_in2)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline long keyctl_pkey_e_d_s(int op,
+				     const struct keyctl_pkey_params __user *params,
+				     const char __user *_info,
+				     const void __user *_in,
+				     void __user *_out)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
+
+#ifdef CONFIG_KEY_NOTIFICATIONS
+extern long keyctl_watch_key(key_serial_t, int, int);
+#else
+static inline long keyctl_watch_key(key_serial_t key_id, int watch_fd, int watch_id)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+/*
+ * Debugging key validation
+ */
+#ifdef KEY_DEBUGGING
+extern void __key_check(const struct key *);
+
+static inline void key_check(const struct key *key)
+{
+	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
+		__key_check(key);
+}
+
+#else
+
+#define key_check(key) do {} while(0)
+
+#endif
+#endif /* _INTERNAL_H */

linux-7.2.3/security/keys/keyctl_pkey.c

@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Public-key operation keyctls
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/key.h>
+#include <linux/keyctl.h>
+#include <linux/parser.h>
+#include <linux/uaccess.h>
+#include <keys/user-type.h>
+#include "internal.h"
+
+static void keyctl_pkey_params_free(struct kernel_pkey_params *params)
+{
+	kfree(params->info);
+	key_put(params->key);
+}
+
+enum {
+	Opt_err,
+	Opt_enc,		/* "enc=<encoding>" eg. "enc=oaep" */
+	Opt_hash,		/* "hash=<digest-name>" eg. "hash=sha1" */
+};
+
+static const match_table_t param_keys = {
+	{ Opt_enc,	"enc=%s" },
+	{ Opt_hash,	"hash=%s" },
+	{ Opt_err,	NULL }
+};
+
+/*
+ * Parse the information string which consists of key=val pairs.
+ */
+static int keyctl_pkey_params_parse(struct kernel_pkey_params *params)
+{
+	unsigned long token_mask = 0;
+	substring_t args[MAX_OPT_ARGS];
+	char *c = params->info, *p, *q;
+	int token;
+
+	while ((p = strsep(&c, " \t"))) {
+		if (*p == '\0' || *p == ' ' || *p == '\t')
+			continue;
+		token = match_token(p, param_keys, args);
+		if (token == Opt_err)
+			return -EINVAL;
+		if (__test_and_set_bit(token, &token_mask))
+			return -EINVAL;
+		q = args[0].from;
+		if (!q[0])
+			return -EINVAL;
+
+		switch (token) {
+		case Opt_enc:
+			params->encoding = q;
+			break;
+
+		case Opt_hash:
+			params->hash_algo = q;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Interpret parameters.  Callers must always call the free function
+ * on params, even if an error is returned.
+ */
+static int keyctl_pkey_params_get(key_serial_t id,
+				  const char __user *_info,
+				  struct kernel_pkey_params *params)
+{
+	key_ref_t key_ref;
+	void *p;
+	int ret;
+
+	memset(params, 0, sizeof(*params));
+	params->encoding = "raw";
+
+	p = strndup_user(_info, PAGE_SIZE);
+	if (IS_ERR(p))
+		return PTR_ERR(p);
+	params->info = p;
+
+	ret = keyctl_pkey_params_parse(params);
+	if (ret < 0)
+		return ret;
+
+	key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
+	if (IS_ERR(key_ref))
+		return PTR_ERR(key_ref);
+	params->key = key_ref_to_ptr(key_ref);
+
+	if (!params->key->type->asym_query)
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
+/*
+ * Get parameters from userspace.  Callers must always call the free function
+ * on params, even if an error is returned.
+ */
+static int keyctl_pkey_params_get_2(const struct keyctl_pkey_params __user *_params,
+				    const char __user *_info,
+				    int op,
+				    struct kernel_pkey_params *params)
+{
+	struct keyctl_pkey_params uparams;
+	struct kernel_pkey_query info;
+	int ret;
+
+	memset(params, 0, sizeof(*params));
+	params->encoding = "raw";
+
+	if (copy_from_user(&uparams, _params, sizeof(uparams)) != 0)
+		return -EFAULT;
+
+	ret = keyctl_pkey_params_get(uparams.key_id, _info, params);
+	if (ret < 0)
+		return ret;
+
+	ret = params->key->type->asym_query(params, &info);
+	if (ret < 0)
+		return ret;
+
+	switch (op) {
+	case KEYCTL_PKEY_ENCRYPT:
+		if (uparams.in_len  > info.max_dec_size ||
+		    uparams.out_len > info.max_enc_size)
+			return -EINVAL;
+
+		params->out_len = info.max_enc_size;
+		break;
+	case KEYCTL_PKEY_DECRYPT:
+		if (uparams.in_len  > info.max_enc_size ||
+		    uparams.out_len > info.max_dec_size)
+			return -EINVAL;
+
+		params->out_len = info.max_dec_size;
+		break;
+	case KEYCTL_PKEY_SIGN:
+		if (uparams.in_len  > info.max_data_size ||
+		    uparams.out_len > info.max_sig_size)
+			return -EINVAL;
+
+		params->out_len = info.max_sig_size;
+		break;
+	case KEYCTL_PKEY_VERIFY:
+		if (uparams.in_len  > info.max_data_size ||
+		    uparams.in2_len > info.max_sig_size)
+			return -EINVAL;
+
+		params->out_len = info.max_sig_size;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	params->in_len  = uparams.in_len;
+	return 0;
+}
+
+/*
+ * Query information about an asymmetric key.
+ */
+long keyctl_pkey_query(key_serial_t id,
+		       const char __user *_info,
+		       struct keyctl_pkey_query __user *_res)
+{
+	struct kernel_pkey_params params;
+	struct kernel_pkey_query res;
+	long ret;
+
+	ret = keyctl_pkey_params_get(id, _info, &params);
+	if (ret < 0)
+		goto error;
+
+	ret = params.key->type->asym_query(&params, &res);
+	if (ret < 0)
+		goto error;
+
+	ret = -EFAULT;
+	if (copy_to_user(_res, &res, sizeof(res)) == 0 &&
+	    clear_user(_res->__spare, sizeof(_res->__spare)) == 0)
+		ret = 0;
+
+error:
+	keyctl_pkey_params_free(&params);
+	return ret;
+}
+
+/*
+ * Encrypt/decrypt/sign
+ *
+ * Encrypt data, decrypt data or sign data using a public key.
+ *
+ * _info is a string of supplementary information in key=val format.  For
+ * instance, it might contain:
+ *
+ *	"enc=pkcs1 hash=sha256"
+ *
+ * where enc= specifies the encoding and hash= selects the OID to go in that
+ * particular encoding if required.  If enc= isn't supplied, it's assumed that
+ * the caller is supplying raw values.
+ *
+ * If successful, the amount of data written into the output buffer is
+ * returned.
+ */
+long keyctl_pkey_e_d_s(int op,
+		       const struct keyctl_pkey_params __user *_params,
+		       const char __user *_info,
+		       const void __user *_in,
+		       void __user *_out)
+{
+	struct kernel_pkey_params params;
+	void *in, *out;
+	long ret;
+
+	ret = keyctl_pkey_params_get_2(_params, _info, op, &params);
+	if (ret < 0)
+		goto error_params;
+
+	ret = -EOPNOTSUPP;
+	if (!params.key->type->asym_eds_op)
+		goto error_params;
+
+	switch (op) {
+	case KEYCTL_PKEY_ENCRYPT:
+		params.op = kernel_pkey_encrypt;
+		break;
+	case KEYCTL_PKEY_DECRYPT:
+		params.op = kernel_pkey_decrypt;
+		break;
+	case KEYCTL_PKEY_SIGN:
+		params.op = kernel_pkey_sign;
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		goto error_params;
+	}
+
+	in = memdup_user(_in, params.in_len);
+	if (IS_ERR(in)) {
+		ret = PTR_ERR(in);
+		goto error_params;
+	}
+
+	ret = -ENOMEM;
+	out = kmalloc(params.out_len, GFP_KERNEL);
+	if (!out)
+		goto error_in;
+
+	ret = params.key->type->asym_eds_op(&params, in, out);
+	if (ret < 0)
+		goto error_out;
+
+	if (copy_to_user(_out, out, ret) != 0)
+		ret = -EFAULT;
+
+error_out:
+	kfree(out);
+error_in:
+	kfree(in);
+error_params:
+	keyctl_pkey_params_free(&params);
+	return ret;
+}
+
+/*
+ * Verify a signature.
+ *
+ * Verify a public key signature using the given key, or if not given, search
+ * for a matching key.
+ *
+ * _info is a string of supplementary information in key=val format.  For
+ * instance, it might contain:
+ *
+ *	"enc=pkcs1 hash=sha256"
+ *
+ * where enc= specifies the signature blob encoding and hash= selects the OID
+ * to go in that particular encoding.  If enc= isn't supplied, it's assumed
+ * that the caller is supplying raw values.
+ *
+ * If successful, 0 is returned.
+ */
+long keyctl_pkey_verify(const struct keyctl_pkey_params __user *_params,
+			const char __user *_info,
+			const void __user *_in,
+			const void __user *_in2)
+{
+	struct kernel_pkey_params params;
+	void *in, *in2;
+	long ret;
+
+	ret = keyctl_pkey_params_get_2(_params, _info, KEYCTL_PKEY_VERIFY,
+				       &params);
+	if (ret < 0)
+		goto error_params;
+
+	ret = -EOPNOTSUPP;
+	if (!params.key->type->asym_verify_signature)
+		goto error_params;
+
+	in = memdup_user(_in, params.in_len);
+	if (IS_ERR(in)) {
+		ret = PTR_ERR(in);
+		goto error_params;
+	}
+
+	in2 = memdup_user(_in2, params.in2_len);
+	if (IS_ERR(in2)) {
+		ret = PTR_ERR(in2);
+		goto error_in;
+	}
+
+	params.op = kernel_pkey_verify;
+	ret = params.key->type->asym_verify_signature(&params, in, in2);
+
+	kfree(in2);
+error_in:
+	kfree(in);
+error_params:
+	keyctl_pkey_params_free(&params);
+	return ret;
+}

linux-7.2.3/security/keys/permission.c

@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Key permission checking
+ *
+ * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/export.h>
+#include <linux/security.h>
+#include "internal.h"
+
+/**
+ * key_task_permission - Check a key can be used
+ * @key_ref: The key to check.
+ * @cred: The credentials to use.
+ * @need_perm: The permission required.
+ *
+ * Check to see whether permission is granted to use a key in the desired way,
+ * but permit the security modules to override.
+ *
+ * The caller must hold either a ref on cred or must hold the RCU readlock.
+ *
+ * Returns 0 if successful, -EACCES if access is denied based on the
+ * permissions bits or the LSM check.
+ */
+int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
+			enum key_need_perm need_perm)
+{
+	struct key *key;
+	key_perm_t kperm, mask;
+	int ret;
+
+	switch (need_perm) {
+	default:
+		WARN_ON(1);
+		return -EACCES;
+	case KEY_NEED_UNLINK:
+	case KEY_SYSADMIN_OVERRIDE:
+	case KEY_AUTHTOKEN_OVERRIDE:
+	case KEY_DEFER_PERM_CHECK:
+		goto lsm;
+
+	case KEY_NEED_VIEW:	mask = KEY_OTH_VIEW;	break;
+	case KEY_NEED_READ:	mask = KEY_OTH_READ;	break;
+	case KEY_NEED_WRITE:	mask = KEY_OTH_WRITE;	break;
+	case KEY_NEED_SEARCH:	mask = KEY_OTH_SEARCH;	break;
+	case KEY_NEED_LINK:	mask = KEY_OTH_LINK;	break;
+	case KEY_NEED_SETATTR:	mask = KEY_OTH_SETATTR;	break;
+	}
+
+	key = key_ref_to_ptr(key_ref);
+
+	/* use the second 8-bits of permissions for keys the caller owns */
+	if (uid_eq(key->uid, cred->fsuid)) {
+		kperm = key->perm >> 16;
+		goto use_these_perms;
+	}
+
+	/* use the third 8-bits of permissions for keys the caller has a group
+	 * membership in common with */
+	if (gid_valid(key->gid) && key->perm & KEY_GRP_ALL) {
+		if (gid_eq(key->gid, cred->fsgid)) {
+			kperm = key->perm >> 8;
+			goto use_these_perms;
+		}
+
+		ret = groups_search(cred->group_info, key->gid);
+		if (ret) {
+			kperm = key->perm >> 8;
+			goto use_these_perms;
+		}
+	}
+
+	/* otherwise use the least-significant 8-bits */
+	kperm = key->perm;
+
+use_these_perms:
+
+	/* use the top 8-bits of permissions for keys the caller possesses
+	 * - possessor permissions are additive with other permissions
+	 */
+	if (is_key_possessed(key_ref))
+		kperm |= key->perm >> 24;
+
+	if ((kperm & mask) != mask)
+		return -EACCES;
+
+	/* let LSM be the final arbiter */
+lsm:
+	return security_key_permission(key_ref, cred, need_perm);
+}
+EXPORT_SYMBOL(key_task_permission);
+
+/**
+ * key_validate - Validate a key.
+ * @key: The key to be validated.
+ *
+ * Check that a key is valid, returning 0 if the key is okay, -ENOKEY if the
+ * key is invalidated, -EKEYREVOKED if the key's type has been removed or if
+ * the key has been revoked or -EKEYEXPIRED if the key has expired.
+ */
+int key_validate(const struct key *key)
+{
+	unsigned long flags = READ_ONCE(key->flags);
+	time64_t expiry = READ_ONCE(key->expiry);
+
+	if (flags & (1 << KEY_FLAG_INVALIDATED))
+		return -ENOKEY;
+
+	/* check it's still accessible */
+	if (flags & ((1 << KEY_FLAG_REVOKED) |
+		     (1 << KEY_FLAG_DEAD)))
+		return -EKEYREVOKED;
+
+	/* check it hasn't expired */
+	if (expiry) {
+		if (ktime_get_real_seconds() >= expiry)
+			return -EKEYEXPIRED;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(key_validate);

linux-7.2.3/security/keys/persistent.c

@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* General persistent per-UID keyrings register
+ *
+ * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/user_namespace.h>
+#include <linux/cred.h>
+
+#include "internal.h"
+
+unsigned persistent_keyring_expiry = 3 * 24 * 3600; /* Expire after 3 days of non-use */
+
+/*
+ * Create the persistent keyring register for the current user namespace.
+ *
+ * Called with the namespace's sem locked for writing.
+ */
+static int key_create_persistent_register(struct user_namespace *ns)
+{
+	struct key *reg = keyring_alloc(".persistent_register",
+					KUIDT_INIT(0), KGIDT_INIT(0),
+					current_cred(),
+					((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+					 KEY_USR_VIEW | KEY_USR_READ),
+					KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
+	if (IS_ERR(reg))
+		return PTR_ERR(reg);
+
+	ns->persistent_keyring_register = reg;
+	return 0;
+}
+
+/*
+ * Create the persistent keyring for the specified user.
+ *
+ * Called with the namespace's sem locked for writing.
+ */
+static key_ref_t key_create_persistent(struct user_namespace *ns, kuid_t uid,
+				       struct keyring_index_key *index_key)
+{
+	struct key *persistent;
+	key_ref_t reg_ref, persistent_ref;
+
+	if (!ns->persistent_keyring_register) {
+		long err = key_create_persistent_register(ns);
+		if (err < 0)
+			return ERR_PTR(err);
+	} else {
+		reg_ref = make_key_ref(ns->persistent_keyring_register, true);
+		persistent_ref = find_key_to_update(reg_ref, index_key);
+		if (persistent_ref)
+			return persistent_ref;
+	}
+
+	persistent = keyring_alloc(index_key->description,
+				   uid, INVALID_GID, current_cred(),
+				   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				    KEY_USR_VIEW | KEY_USR_READ),
+				   KEY_ALLOC_NOT_IN_QUOTA, NULL,
+				   ns->persistent_keyring_register);
+	if (IS_ERR(persistent))
+		return ERR_CAST(persistent);
+
+	return make_key_ref(persistent, true);
+}
+
+/*
+ * Get the persistent keyring for a specific UID and link it to the nominated
+ * keyring.
+ */
+static long key_get_persistent(struct user_namespace *ns, kuid_t uid,
+			       key_ref_t dest_ref)
+{
+	struct keyring_index_key index_key;
+	struct key *persistent;
+	key_ref_t reg_ref, persistent_ref;
+	char buf[32];
+	long ret;
+
+	/* Look in the register if it exists */
+	memset(&index_key, 0, sizeof(index_key));
+	index_key.type = &key_type_keyring;
+	index_key.description = buf;
+	index_key.desc_len = sprintf(buf, "_persistent.%u", from_kuid(ns, uid));
+	key_set_index_key(&index_key);
+
+	if (ns->persistent_keyring_register) {
+		reg_ref = make_key_ref(ns->persistent_keyring_register, true);
+		down_read(&ns->keyring_sem);
+		persistent_ref = find_key_to_update(reg_ref, &index_key);
+		up_read(&ns->keyring_sem);
+
+		if (persistent_ref)
+			goto found;
+	}
+
+	/* It wasn't in the register, so we'll need to create it.  We might
+	 * also need to create the register.
+	 */
+	down_write(&ns->keyring_sem);
+	persistent_ref = key_create_persistent(ns, uid, &index_key);
+	up_write(&ns->keyring_sem);
+	if (!IS_ERR(persistent_ref))
+		goto found;
+
+	return PTR_ERR(persistent_ref);
+
+found:
+	ret = key_task_permission(persistent_ref, current_cred(), KEY_NEED_LINK);
+	if (ret == 0) {
+		persistent = key_ref_to_ptr(persistent_ref);
+		ret = key_link(key_ref_to_ptr(dest_ref), persistent);
+		if (ret == 0) {
+			key_set_timeout(persistent, persistent_keyring_expiry);
+			ret = persistent->serial;
+		}
+	}
+
+	key_ref_put(persistent_ref);
+	return ret;
+}
+
+/*
+ * Get the persistent keyring for a specific UID and link it to the nominated
+ * keyring.
+ */
+long keyctl_get_persistent(uid_t _uid, key_serial_t destid)
+{
+	struct user_namespace *ns = current_user_ns();
+	key_ref_t dest_ref;
+	kuid_t uid;
+	long ret;
+
+	/* -1 indicates the current user */
+	if (_uid == (uid_t)-1) {
+		uid = current_uid();
+	} else {
+		uid = make_kuid(ns, _uid);
+		if (!uid_valid(uid))
+			return -EINVAL;
+
+		/* You can only see your own persistent cache if you're not
+		 * sufficiently privileged.
+		 */
+		if (!uid_eq(uid, current_uid()) &&
+		    !uid_eq(uid, current_euid()) &&
+		    !ns_capable(ns, CAP_SETUID))
+			return -EPERM;
+	}
+
+	/* There must be a destination keyring */
+	dest_ref = lookup_user_key(destid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
+	if (IS_ERR(dest_ref))
+		return PTR_ERR(dest_ref);
+	if (key_ref_to_ptr(dest_ref)->type != &key_type_keyring) {
+		ret = -ENOTDIR;
+		goto out_put_dest;
+	}
+
+	ret = key_get_persistent(ns, uid, dest_ref);
+
+out_put_dest:
+	key_ref_put(dest_ref);
+	return ret;
+}

linux-7.2.3/security/keys/proc.c

@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* procfs files for key database enumeration
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <asm/errno.h>
+#include "internal.h"
+
+static void *proc_keys_start(struct seq_file *p, loff_t *_pos);
+static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos);
+static void proc_keys_stop(struct seq_file *p, void *v);
+static int proc_keys_show(struct seq_file *m, void *v);
+
+static const struct seq_operations proc_keys_ops = {
+	.start	= proc_keys_start,
+	.next	= proc_keys_next,
+	.stop	= proc_keys_stop,
+	.show	= proc_keys_show,
+};
+
+static void *proc_key_users_start(struct seq_file *p, loff_t *_pos);
+static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos);
+static void proc_key_users_stop(struct seq_file *p, void *v);
+static int proc_key_users_show(struct seq_file *m, void *v);
+
+static const struct seq_operations proc_key_users_ops = {
+	.start	= proc_key_users_start,
+	.next	= proc_key_users_next,
+	.stop	= proc_key_users_stop,
+	.show	= proc_key_users_show,
+};
+
+/*
+ * Declare the /proc files.
+ */
+static int __init key_proc_init(void)
+{
+	struct proc_dir_entry *p;
+
+	p = proc_create_seq("keys", 0, NULL, &proc_keys_ops);
+	if (!p)
+		panic("Cannot create /proc/keys\n");
+
+	p = proc_create_seq("key-users", 0, NULL, &proc_key_users_ops);
+	if (!p)
+		panic("Cannot create /proc/key-users\n");
+
+	return 0;
+}
+
+__initcall(key_proc_init);
+
+/*
+ * Implement "/proc/keys" to provide a list of the keys on the system that
+ * grant View permission to the caller.
+ */
+static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n)
+{
+	struct user_namespace *user_ns = seq_user_ns(p);
+
+	n = rb_next(n);
+	while (n) {
+		struct key *key = rb_entry(n, struct key, serial_node);
+		if (kuid_has_mapping(user_ns, key->user->uid))
+			break;
+		n = rb_next(n);
+	}
+	return n;
+}
+
+static struct key *find_ge_key(struct seq_file *p, key_serial_t id)
+{
+	struct user_namespace *user_ns = seq_user_ns(p);
+	struct rb_node *n = key_serial_tree.rb_node;
+	struct key *minkey = NULL;
+
+	while (n) {
+		struct key *key = rb_entry(n, struct key, serial_node);
+		if (id < key->serial) {
+			if (!minkey || minkey->serial > key->serial)
+				minkey = key;
+			n = n->rb_left;
+		} else if (id > key->serial) {
+			n = n->rb_right;
+		} else {
+			minkey = key;
+			break;
+		}
+		key = NULL;
+	}
+
+	if (!minkey)
+		return NULL;
+
+	for (;;) {
+		if (kuid_has_mapping(user_ns, minkey->user->uid))
+			return minkey;
+		n = rb_next(&minkey->serial_node);
+		if (!n)
+			return NULL;
+		minkey = rb_entry(n, struct key, serial_node);
+	}
+}
+
+static void *proc_keys_start(struct seq_file *p, loff_t *_pos)
+	__acquires(key_serial_lock)
+{
+	key_serial_t pos = *_pos;
+	struct key *key;
+
+	spin_lock(&key_serial_lock);
+
+	if (*_pos > INT_MAX)
+		return NULL;
+	key = find_ge_key(p, pos);
+	if (!key)
+		return NULL;
+	*_pos = key->serial;
+	return &key->serial_node;
+}
+
+static inline key_serial_t key_node_serial(struct rb_node *n)
+{
+	struct key *key = rb_entry(n, struct key, serial_node);
+	return key->serial;
+}
+
+static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
+{
+	struct rb_node *n;
+
+	n = key_serial_next(p, v);
+	if (n)
+		*_pos = key_node_serial(n);
+	else
+		(*_pos)++;
+	return n;
+}
+
+static void proc_keys_stop(struct seq_file *p, void *v)
+	__releases(key_serial_lock)
+{
+	spin_unlock(&key_serial_lock);
+}
+
+static int proc_keys_show(struct seq_file *m, void *v)
+{
+	struct rb_node *_p = v;
+	struct key *key = rb_entry(_p, struct key, serial_node);
+	unsigned long flags;
+	key_ref_t key_ref, skey_ref;
+	time64_t now, expiry;
+	char xbuf[16];
+	short state;
+	u64 timo;
+	int rc;
+
+	struct keyring_search_context ctx = {
+		.index_key		= key->index_key,
+		.cred			= m->file->f_cred,
+		.match_data.cmp		= lookup_user_key_possessed,
+		.match_data.raw_data	= key,
+		.match_data.lookup_type	= KEYRING_SEARCH_LOOKUP_DIRECT,
+		.flags			= (KEYRING_SEARCH_NO_STATE_CHECK |
+					   KEYRING_SEARCH_RECURSE),
+	};
+
+	key_ref = make_key_ref(key, 0);
+
+	/* determine if the key is possessed by this process (a test we can
+	 * skip if the key does not indicate the possessor can view it
+	 */
+	if (key->perm & KEY_POS_VIEW) {
+		rcu_read_lock();
+		skey_ref = search_cred_keyrings_rcu(&ctx);
+		rcu_read_unlock();
+		if (!IS_ERR(skey_ref)) {
+			key_ref_put(skey_ref);
+			key_ref = make_key_ref(key, 1);
+		}
+	}
+
+	/* check whether the current task is allowed to view the key */
+	rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
+	if (rc < 0)
+		return 0;
+
+	now = ktime_get_real_seconds();
+
+	rcu_read_lock();
+
+	/* come up with a suitable timeout value */
+	expiry = READ_ONCE(key->expiry);
+	if (expiry == TIME64_MAX) {
+		memcpy(xbuf, "perm", 5);
+	} else if (now >= expiry) {
+		memcpy(xbuf, "expd", 5);
+	} else {
+		timo = expiry - now;
+
+		if (timo < 60)
+			sprintf(xbuf, "%llus", timo);
+		else if (timo < 60*60)
+			sprintf(xbuf, "%llum", div_u64(timo, 60));
+		else if (timo < 60*60*24)
+			sprintf(xbuf, "%lluh", div_u64(timo, 60 * 60));
+		else if (timo < 60*60*24*7)
+			sprintf(xbuf, "%llud", div_u64(timo, 60 * 60 * 24));
+		else
+			sprintf(xbuf, "%lluw", div_u64(timo, 60 * 60 * 24 * 7));
+	}
+
+	state = key_read_state(key);
+
+#define showflag(FLAGS, LETTER, FLAG) \
+	((FLAGS & (1 << FLAG)) ? LETTER : '-')
+
+	flags = READ_ONCE(key->flags);
+	seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
+		   key->serial,
+		   state != KEY_IS_UNINSTANTIATED ? 'I' : '-',
+		   showflag(flags, 'R', KEY_FLAG_REVOKED),
+		   showflag(flags, 'D', KEY_FLAG_DEAD),
+		   showflag(flags, 'Q', KEY_FLAG_IN_QUOTA),
+		   showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT),
+		   state < 0 ? 'N' : '-',
+		   showflag(flags, 'i', KEY_FLAG_INVALIDATED),
+		   refcount_read(&key->usage),
+		   xbuf,
+		   key->perm,
+		   from_kuid_munged(seq_user_ns(m), key->uid),
+		   from_kgid_munged(seq_user_ns(m), key->gid),
+		   key->type->name);
+
+#undef showflag
+
+	if (key->type->describe)
+		key->type->describe(key, m);
+	seq_putc(m, '\n');
+
+	rcu_read_unlock();
+	return 0;
+}
+
+static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n)
+{
+	while (n) {
+		struct key_user *user = rb_entry(n, struct key_user, node);
+		if (kuid_has_mapping(user_ns, user->uid))
+			break;
+		n = rb_next(n);
+	}
+	return n;
+}
+
+static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n)
+{
+	return __key_user_next(user_ns, rb_next(n));
+}
+
+static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r)
+{
+	struct rb_node *n = rb_first(r);
+	return __key_user_next(user_ns, n);
+}
+
+static void *proc_key_users_start(struct seq_file *p, loff_t *_pos)
+	__acquires(key_user_lock)
+{
+	struct rb_node *_p;
+	loff_t pos = *_pos;
+
+	spin_lock(&key_user_lock);
+
+	_p = key_user_first(seq_user_ns(p), &key_user_tree);
+	while (pos > 0 && _p) {
+		pos--;
+		_p = key_user_next(seq_user_ns(p), _p);
+	}
+
+	return _p;
+}
+
+static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos)
+{
+	(*_pos)++;
+	return key_user_next(seq_user_ns(p), (struct rb_node *)v);
+}
+
+static void proc_key_users_stop(struct seq_file *p, void *v)
+	__releases(key_user_lock)
+{
+	spin_unlock(&key_user_lock);
+}
+
+static int proc_key_users_show(struct seq_file *m, void *v)
+{
+	struct rb_node *_p = v;
+	struct key_user *user = rb_entry(_p, struct key_user, node);
+	unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
+		key_quota_root_maxkeys : key_quota_maxkeys;
+	unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
+		key_quota_root_maxbytes : key_quota_maxbytes;
+
+	seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
+		   from_kuid_munged(seq_user_ns(m), user->uid),
+		   refcount_read(&user->usage),
+		   atomic_read(&user->nkeys),
+		   atomic_read(&user->nikeys),
+		   user->qnkeys,
+		   maxkeys,
+		   user->qnbytes,
+		   maxbytes);
+
+	return 0;
+}

linux-7.2.3/security/keys/process_keys.c

@@ -0,0 +1,965 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Manage a process's keyrings
+ *
+ * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/sched/user.h>
+#include <linux/keyctl.h>
+#include <linux/fs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/security.h>
+#include <linux/user_namespace.h>
+#include <linux/uaccess.h>
+#include <linux/init_task.h>
+#include <keys/request_key_auth-type.h>
+#include "internal.h"
+
+/* Session keyring create vs join semaphore */
+static DEFINE_MUTEX(key_session_mutex);
+
+/* The root user's tracking struct */
+struct key_user root_key_user = {
+	.usage		= REFCOUNT_INIT(3),
+	.cons_lock	= __MUTEX_INITIALIZER(root_key_user.cons_lock),
+	.lock		= __SPIN_LOCK_UNLOCKED(root_key_user.lock),
+	.nkeys		= ATOMIC_INIT(2),
+	.nikeys		= ATOMIC_INIT(2),
+	.uid		= GLOBAL_ROOT_UID,
+};
+
+/*
+ * Get or create a user register keyring.
+ */
+static struct key *get_user_register(struct user_namespace *user_ns)
+{
+	struct key *reg_keyring = READ_ONCE(user_ns->user_keyring_register);
+
+	if (reg_keyring)
+		return reg_keyring;
+
+	down_write(&user_ns->keyring_sem);
+
+	/* Make sure there's a register keyring.  It gets owned by the
+	 * user_namespace's owner.
+	 */
+	reg_keyring = user_ns->user_keyring_register;
+	if (!reg_keyring) {
+		reg_keyring = keyring_alloc(".user_reg",
+					    user_ns->owner, INVALID_GID,
+					    kernel_cred(),
+					    KEY_POS_WRITE | KEY_POS_SEARCH |
+					    KEY_USR_VIEW | KEY_USR_READ,
+					    0,
+					    NULL, NULL);
+		if (!IS_ERR(reg_keyring))
+			smp_store_release(&user_ns->user_keyring_register,
+					  reg_keyring);
+	}
+
+	up_write(&user_ns->keyring_sem);
+
+	/* We don't return a ref since the keyring is pinned by the user_ns */
+	return reg_keyring;
+}
+
+/*
+ * Look up the user and user session keyrings for the current process's UID,
+ * creating them if they don't exist.
+ */
+int look_up_user_keyrings(struct key **_user_keyring,
+			  struct key **_user_session_keyring)
+{
+	const struct cred *cred = current_cred();
+	struct user_namespace *user_ns = current_user_ns();
+	struct key *reg_keyring, *uid_keyring, *session_keyring;
+	key_perm_t user_keyring_perm;
+	key_ref_t uid_keyring_r, session_keyring_r;
+	uid_t uid = from_kuid(user_ns, cred->user->uid);
+	char buf[20];
+	int ret;
+
+	user_keyring_perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL;
+
+	kenter("%u", uid);
+
+	reg_keyring = get_user_register(user_ns);
+	if (IS_ERR(reg_keyring))
+		return PTR_ERR(reg_keyring);
+
+	down_write(&user_ns->keyring_sem);
+	ret = 0;
+
+	/* Get the user keyring.  Note that there may be one in existence
+	 * already as it may have been pinned by a session, but the user_struct
+	 * pointing to it may have been destroyed by setuid.
+	 */
+	snprintf(buf, sizeof(buf), "_uid.%u", uid);
+	uid_keyring_r = keyring_search(make_key_ref(reg_keyring, true),
+				       &key_type_keyring, buf, false);
+	kdebug("_uid %p", uid_keyring_r);
+	if (uid_keyring_r == ERR_PTR(-EAGAIN)) {
+		uid_keyring = keyring_alloc(buf, cred->user->uid, INVALID_GID,
+					    cred, user_keyring_perm,
+					    KEY_ALLOC_UID_KEYRING |
+					    KEY_ALLOC_IN_QUOTA,
+					    NULL, reg_keyring);
+		if (IS_ERR(uid_keyring)) {
+			ret = PTR_ERR(uid_keyring);
+			goto error;
+		}
+	} else if (IS_ERR(uid_keyring_r)) {
+		ret = PTR_ERR(uid_keyring_r);
+		goto error;
+	} else {
+		uid_keyring = key_ref_to_ptr(uid_keyring_r);
+	}
+
+	/* Get a default session keyring (which might also exist already) */
+	snprintf(buf, sizeof(buf), "_uid_ses.%u", uid);
+	session_keyring_r = keyring_search(make_key_ref(reg_keyring, true),
+					   &key_type_keyring, buf, false);
+	kdebug("_uid_ses %p", session_keyring_r);
+	if (session_keyring_r == ERR_PTR(-EAGAIN)) {
+		session_keyring = keyring_alloc(buf, cred->user->uid, INVALID_GID,
+						cred, user_keyring_perm,
+						KEY_ALLOC_UID_KEYRING |
+						KEY_ALLOC_IN_QUOTA,
+						NULL, NULL);
+		if (IS_ERR(session_keyring)) {
+			ret = PTR_ERR(session_keyring);
+			goto error_release;
+		}
+
+		/* We install a link from the user session keyring to
+		 * the user keyring.
+		 */
+		ret = key_link(session_keyring, uid_keyring);
+		if (ret < 0)
+			goto error_release_session;
+
+		/* And only then link the user-session keyring to the
+		 * register.
+		 */
+		ret = key_link(reg_keyring, session_keyring);
+		if (ret < 0)
+			goto error_release_session;
+	} else if (IS_ERR(session_keyring_r)) {
+		ret = PTR_ERR(session_keyring_r);
+		goto error_release;
+	} else {
+		session_keyring = key_ref_to_ptr(session_keyring_r);
+	}
+
+	up_write(&user_ns->keyring_sem);
+
+	if (_user_session_keyring)
+		*_user_session_keyring = session_keyring;
+	else
+		key_put(session_keyring);
+	if (_user_keyring)
+		*_user_keyring = uid_keyring;
+	else
+		key_put(uid_keyring);
+	kleave(" = 0");
+	return 0;
+
+error_release_session:
+	key_put(session_keyring);
+error_release:
+	key_put(uid_keyring);
+error:
+	up_write(&user_ns->keyring_sem);
+	kleave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Get the user session keyring if it exists, but don't create it if it
+ * doesn't.
+ */
+struct key *get_user_session_keyring_rcu(const struct cred *cred)
+{
+	struct key *reg_keyring = READ_ONCE(cred->user_ns->user_keyring_register);
+	key_ref_t session_keyring_r;
+	char buf[20];
+
+	struct keyring_search_context ctx = {
+		.index_key.type		= &key_type_keyring,
+		.index_key.description	= buf,
+		.cred			= cred,
+		.match_data.cmp		= key_default_cmp,
+		.match_data.raw_data	= buf,
+		.match_data.lookup_type	= KEYRING_SEARCH_LOOKUP_DIRECT,
+		.flags			= KEYRING_SEARCH_DO_STATE_CHECK,
+	};
+
+	if (!reg_keyring)
+		return NULL;
+
+	ctx.index_key.desc_len = snprintf(buf, sizeof(buf), "_uid_ses.%u",
+					  from_kuid(cred->user_ns,
+						    cred->user->uid));
+
+	session_keyring_r = keyring_search_rcu(make_key_ref(reg_keyring, true),
+					       &ctx);
+	if (IS_ERR(session_keyring_r))
+		return NULL;
+	return key_ref_to_ptr(session_keyring_r);
+}
+
+/*
+ * Install a thread keyring to the given credentials struct if it didn't have
+ * one already.  This is allowed to overrun the quota.
+ *
+ * Return: 0 if a thread keyring is now present; -errno on failure.
+ */
+int install_thread_keyring_to_cred(struct cred *new)
+{
+	struct key *keyring;
+
+	if (new->thread_keyring)
+		return 0;
+
+	keyring = keyring_alloc("_tid", new->uid, new->gid, new,
+				KEY_POS_ALL | KEY_USR_VIEW,
+				KEY_ALLOC_QUOTA_OVERRUN,
+				NULL, NULL);
+	if (IS_ERR(keyring))
+		return PTR_ERR(keyring);
+
+	new->thread_keyring = keyring;
+	return 0;
+}
+
+/*
+ * Install a thread keyring to the current task if it didn't have one already.
+ *
+ * Return: 0 if a thread keyring is now present; -errno on failure.
+ */
+static int install_thread_keyring(void)
+{
+	struct cred *new;
+	int ret;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+
+	ret = install_thread_keyring_to_cred(new);
+	if (ret < 0) {
+		abort_creds(new);
+		return ret;
+	}
+
+	return commit_creds(new);
+}
+
+/*
+ * Install a process keyring to the given credentials struct if it didn't have
+ * one already.  This is allowed to overrun the quota.
+ *
+ * Return: 0 if a process keyring is now present; -errno on failure.
+ */
+int install_process_keyring_to_cred(struct cred *new)
+{
+	struct key *keyring;
+
+	if (new->process_keyring)
+		return 0;
+
+	keyring = keyring_alloc("_pid", new->uid, new->gid, new,
+				KEY_POS_ALL | KEY_USR_VIEW,
+				KEY_ALLOC_QUOTA_OVERRUN,
+				NULL, NULL);
+	if (IS_ERR(keyring))
+		return PTR_ERR(keyring);
+
+	new->process_keyring = keyring;
+	return 0;
+}
+
+/*
+ * Install a process keyring to the current task if it didn't have one already.
+ *
+ * Return: 0 if a process keyring is now present; -errno on failure.
+ */
+static int install_process_keyring(void)
+{
+	struct cred *new;
+	int ret;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+
+	ret = install_process_keyring_to_cred(new);
+	if (ret < 0) {
+		abort_creds(new);
+		return ret;
+	}
+
+	return commit_creds(new);
+}
+
+/*
+ * Install the given keyring as the session keyring of the given credentials
+ * struct, replacing the existing one if any.  If the given keyring is NULL,
+ * then install a new anonymous session keyring.
+ * @cred can not be in use by any task yet.
+ *
+ * Return: 0 on success; -errno on failure.
+ */
+int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
+{
+	unsigned long flags;
+	struct key *old;
+
+	might_sleep();
+
+	/* create an empty session keyring */
+	if (!keyring) {
+		flags = KEY_ALLOC_QUOTA_OVERRUN;
+		if (cred->session_keyring)
+			flags = KEY_ALLOC_IN_QUOTA;
+
+		keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred,
+					KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
+					flags, NULL, NULL);
+		if (IS_ERR(keyring))
+			return PTR_ERR(keyring);
+	} else {
+		__key_get(keyring);
+	}
+
+	/* install the keyring */
+	old = cred->session_keyring;
+	cred->session_keyring = keyring;
+
+	if (old)
+		key_put(old);
+
+	return 0;
+}
+
+/*
+ * Install the given keyring as the session keyring of the current task,
+ * replacing the existing one if any.  If the given keyring is NULL, then
+ * install a new anonymous session keyring.
+ *
+ * Return: 0 on success; -errno on failure.
+ */
+static int install_session_keyring(struct key *keyring)
+{
+	struct cred *new;
+	int ret;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+
+	ret = install_session_keyring_to_cred(new, keyring);
+	if (ret < 0) {
+		abort_creds(new);
+		return ret;
+	}
+
+	return commit_creds(new);
+}
+
+/*
+ * Handle the fsuid changing.
+ */
+void key_fsuid_changed(struct cred *new_cred)
+{
+	/* update the ownership of the thread keyring */
+	if (new_cred->thread_keyring) {
+		down_write(&new_cred->thread_keyring->sem);
+		new_cred->thread_keyring->uid = new_cred->fsuid;
+		up_write(&new_cred->thread_keyring->sem);
+	}
+}
+
+/*
+ * Handle the fsgid changing.
+ */
+void key_fsgid_changed(struct cred *new_cred)
+{
+	/* update the ownership of the thread keyring */
+	if (new_cred->thread_keyring) {
+		down_write(&new_cred->thread_keyring->sem);
+		new_cred->thread_keyring->gid = new_cred->fsgid;
+		up_write(&new_cred->thread_keyring->sem);
+	}
+}
+
+/*
+ * Search the process keyrings attached to the supplied cred for the first
+ * matching key under RCU conditions (the caller must be holding the RCU read
+ * lock).
+ *
+ * The search criteria are the type and the match function.  The description is
+ * given to the match function as a parameter, but doesn't otherwise influence
+ * the search.  Typically the match function will compare the description
+ * parameter to the key's description.
+ *
+ * This can only search keyrings that grant Search permission to the supplied
+ * credentials.  Keyrings linked to searched keyrings will also be searched if
+ * they grant Search permission too.  Keys can only be found if they grant
+ * Search permission to the credentials.
+ *
+ * Returns a pointer to the key with the key usage count incremented if
+ * successful, -EAGAIN if we didn't find any matching key or -ENOKEY if we only
+ * matched negative keys.
+ *
+ * In the case of a successful return, the possession attribute is set on the
+ * returned key reference.
+ */
+key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx)
+{
+	struct key *user_session;
+	key_ref_t key_ref, ret, err;
+	const struct cred *cred = ctx->cred;
+
+	/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
+	 * searchable, but we failed to find a key or we found a negative key;
+	 * otherwise we want to return a sample error (probably -EACCES) if
+	 * none of the keyrings were searchable
+	 *
+	 * in terms of priority: success > -ENOKEY > -EAGAIN > other error
+	 */
+	key_ref = NULL;
+	ret = NULL;
+	err = ERR_PTR(-EAGAIN);
+
+	/* search the thread keyring first */
+	if (cred->thread_keyring) {
+		key_ref = keyring_search_rcu(
+			make_key_ref(cred->thread_keyring, 1), ctx);
+		if (!IS_ERR(key_ref))
+			goto found;
+
+		switch (PTR_ERR(key_ref)) {
+		case -EAGAIN: /* no key */
+		case -ENOKEY: /* negative key */
+			ret = key_ref;
+			break;
+		default:
+			err = key_ref;
+			break;
+		}
+	}
+
+	/* search the process keyring second */
+	if (cred->process_keyring) {
+		key_ref = keyring_search_rcu(
+			make_key_ref(cred->process_keyring, 1), ctx);
+		if (!IS_ERR(key_ref))
+			goto found;
+
+		switch (PTR_ERR(key_ref)) {
+		case -EAGAIN: /* no key */
+			if (ret)
+				break;
+			fallthrough;
+		case -ENOKEY: /* negative key */
+			ret = key_ref;
+			break;
+		default:
+			err = key_ref;
+			break;
+		}
+	}
+
+	/* search the session keyring */
+	if (cred->session_keyring) {
+		key_ref = keyring_search_rcu(
+			make_key_ref(cred->session_keyring, 1), ctx);
+
+		if (!IS_ERR(key_ref))
+			goto found;
+
+		switch (PTR_ERR(key_ref)) {
+		case -EAGAIN: /* no key */
+			if (ret)
+				break;
+			fallthrough;
+		case -ENOKEY: /* negative key */
+			ret = key_ref;
+			break;
+		default:
+			err = key_ref;
+			break;
+		}
+	}
+	/* or search the user-session keyring */
+	else if ((user_session = get_user_session_keyring_rcu(cred))) {
+		key_ref = keyring_search_rcu(make_key_ref(user_session, 1),
+					     ctx);
+		key_put(user_session);
+
+		if (!IS_ERR(key_ref))
+			goto found;
+
+		switch (PTR_ERR(key_ref)) {
+		case -EAGAIN: /* no key */
+			if (ret)
+				break;
+			fallthrough;
+		case -ENOKEY: /* negative key */
+			ret = key_ref;
+			break;
+		default:
+			err = key_ref;
+			break;
+		}
+	}
+
+	/* no key - decide on the error we're going to go for */
+	key_ref = ret ? ret : err;
+
+found:
+	return key_ref;
+}
+
+/*
+ * Search the process keyrings attached to the supplied cred for the first
+ * matching key in the manner of search_my_process_keyrings(), but also search
+ * the keys attached to the assumed authorisation key using its credentials if
+ * one is available.
+ *
+ * The caller must be holding the RCU read lock.
+ *
+ * Return same as search_cred_keyrings_rcu().
+ */
+key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx)
+{
+	struct request_key_auth *rka;
+	key_ref_t key_ref, ret = ERR_PTR(-EACCES), err;
+
+	key_ref = search_cred_keyrings_rcu(ctx);
+	if (!IS_ERR(key_ref))
+		goto found;
+	err = key_ref;
+
+	/* if this process has an instantiation authorisation key, then we also
+	 * search the keyrings of the process mentioned there
+	 * - we don't permit access to request_key auth keys via this method
+	 */
+	if (ctx->cred->request_key_auth &&
+	    ctx->cred == current_cred() &&
+	    ctx->index_key.type != &key_type_request_key_auth
+	    ) {
+		const struct cred *cred = ctx->cred;
+
+		if (key_validate(cred->request_key_auth) == 0) {
+			rka = ctx->cred->request_key_auth->payload.data[0];
+
+			//// was search_process_keyrings() [ie. recursive]
+			ctx->cred = rka->cred;
+			key_ref = search_cred_keyrings_rcu(ctx);
+			ctx->cred = cred;
+
+			if (!IS_ERR(key_ref))
+				goto found;
+			ret = key_ref;
+		}
+	}
+
+	/* no key - decide on the error we're going to go for */
+	if (err == ERR_PTR(-ENOKEY) || ret == ERR_PTR(-ENOKEY))
+		key_ref = ERR_PTR(-ENOKEY);
+	else if (err == ERR_PTR(-EACCES))
+		key_ref = ret;
+	else
+		key_ref = err;
+
+found:
+	return key_ref;
+}
+/*
+ * See if the key we're looking at is the target key.
+ */
+bool lookup_user_key_possessed(const struct key *key,
+			       const struct key_match_data *match_data)
+{
+	return key == match_data->raw_data;
+}
+
+/*
+ * Look up a key ID given us by userspace with a given permissions mask to get
+ * the key it refers to.
+ *
+ * Flags can be passed to request that special keyrings be created if referred
+ * to directly, to permit partially constructed keys to be found and to skip
+ * validity and permission checks on the found key.
+ *
+ * Returns a pointer to the key with an incremented usage count if successful;
+ * -EINVAL if the key ID is invalid; -ENOKEY if the key ID does not correspond
+ * to a key or the best found key was a negative key; -EKEYREVOKED or
+ * -EKEYEXPIRED if the best found key was revoked or expired; -EACCES if the
+ * found key doesn't grant the requested permit or the LSM denied access to it;
+ * or -ENOMEM if a special keyring couldn't be created.
+ *
+ * In the case of a successful return, the possession attribute is set on the
+ * returned key reference.
+ */
+key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
+			  enum key_need_perm need_perm)
+{
+	struct keyring_search_context ctx = {
+		.match_data.cmp		= lookup_user_key_possessed,
+		.match_data.lookup_type	= KEYRING_SEARCH_LOOKUP_DIRECT,
+		.flags			= (KEYRING_SEARCH_NO_STATE_CHECK |
+					   KEYRING_SEARCH_RECURSE),
+	};
+	struct request_key_auth *rka;
+	struct key *key, *user_session;
+	key_ref_t key_ref, skey_ref;
+	int ret;
+
+try_again:
+	ctx.cred = get_current_cred();
+	key_ref = ERR_PTR(-ENOKEY);
+
+	switch (id) {
+	case KEY_SPEC_THREAD_KEYRING:
+		if (!ctx.cred->thread_keyring) {
+			if (!(lflags & KEY_LOOKUP_CREATE))
+				goto error;
+
+			ret = install_thread_keyring();
+			if (ret < 0) {
+				key_ref = ERR_PTR(ret);
+				goto error;
+			}
+			goto reget_creds;
+		}
+
+		key = ctx.cred->thread_keyring;
+		__key_get(key);
+		key_ref = make_key_ref(key, 1);
+		break;
+
+	case KEY_SPEC_PROCESS_KEYRING:
+		if (!ctx.cred->process_keyring) {
+			if (!(lflags & KEY_LOOKUP_CREATE))
+				goto error;
+
+			ret = install_process_keyring();
+			if (ret < 0) {
+				key_ref = ERR_PTR(ret);
+				goto error;
+			}
+			goto reget_creds;
+		}
+
+		key = ctx.cred->process_keyring;
+		__key_get(key);
+		key_ref = make_key_ref(key, 1);
+		break;
+
+	case KEY_SPEC_SESSION_KEYRING:
+		if (!ctx.cred->session_keyring) {
+			/* always install a session keyring upon access if one
+			 * doesn't exist yet */
+			ret = look_up_user_keyrings(NULL, &user_session);
+			if (ret < 0)
+				goto error;
+			if (lflags & KEY_LOOKUP_CREATE)
+				ret = join_session_keyring(NULL);
+			else
+				ret = install_session_keyring(user_session);
+
+			key_put(user_session);
+			if (ret < 0)
+				goto error;
+			goto reget_creds;
+		} else if (test_bit(KEY_FLAG_UID_KEYRING,
+				    &ctx.cred->session_keyring->flags) &&
+			   lflags & KEY_LOOKUP_CREATE) {
+			ret = join_session_keyring(NULL);
+			if (ret < 0)
+				goto error;
+			goto reget_creds;
+		}
+
+		key = ctx.cred->session_keyring;
+		__key_get(key);
+		key_ref = make_key_ref(key, 1);
+		break;
+
+	case KEY_SPEC_USER_KEYRING:
+		ret = look_up_user_keyrings(&key, NULL);
+		if (ret < 0)
+			goto error;
+		key_ref = make_key_ref(key, 1);
+		break;
+
+	case KEY_SPEC_USER_SESSION_KEYRING:
+		ret = look_up_user_keyrings(NULL, &key);
+		if (ret < 0)
+			goto error;
+		key_ref = make_key_ref(key, 1);
+		break;
+
+	case KEY_SPEC_GROUP_KEYRING:
+		/* group keyrings are not yet supported */
+		key_ref = ERR_PTR(-EINVAL);
+		goto error;
+
+	case KEY_SPEC_REQKEY_AUTH_KEY:
+		key = ctx.cred->request_key_auth;
+		if (!key)
+			goto error;
+
+		__key_get(key);
+		key_ref = make_key_ref(key, 1);
+		break;
+
+	case KEY_SPEC_REQUESTOR_KEYRING:
+		if (!ctx.cred->request_key_auth)
+			goto error;
+
+		down_read(&ctx.cred->request_key_auth->sem);
+		if (test_bit(KEY_FLAG_REVOKED,
+			     &ctx.cred->request_key_auth->flags)) {
+			key_ref = ERR_PTR(-EKEYREVOKED);
+			key = NULL;
+		} else {
+			rka = ctx.cred->request_key_auth->payload.data[0];
+			key = rka->dest_keyring;
+			__key_get(key);
+		}
+		up_read(&ctx.cred->request_key_auth->sem);
+		if (!key)
+			goto error;
+		key_ref = make_key_ref(key, 1);
+		break;
+
+	default:
+		key_ref = ERR_PTR(-EINVAL);
+		if (id < 1)
+			goto error;
+
+		key = key_lookup(id);
+		if (IS_ERR(key)) {
+			key_ref = ERR_CAST(key);
+			goto error;
+		}
+
+		key_ref = make_key_ref(key, 0);
+
+		/* check to see if we possess the key */
+		ctx.index_key			= key->index_key;
+		ctx.match_data.raw_data		= key;
+		kdebug("check possessed");
+		rcu_read_lock();
+		skey_ref = search_process_keyrings_rcu(&ctx);
+		rcu_read_unlock();
+		kdebug("possessed=%p", skey_ref);
+
+		if (!IS_ERR(skey_ref)) {
+			key_put(key);
+			key_ref = skey_ref;
+		}
+
+		break;
+	}
+
+	/* unlink does not use the nominated key in any way, so can skip all
+	 * the permission checks as it is only concerned with the keyring */
+	if (need_perm != KEY_NEED_UNLINK) {
+		if (!(lflags & KEY_LOOKUP_PARTIAL)) {
+			ret = wait_for_key_construction(key, true);
+			switch (ret) {
+			case -ERESTARTSYS:
+				goto invalid_key;
+			default:
+				if (need_perm != KEY_AUTHTOKEN_OVERRIDE &&
+				    need_perm != KEY_DEFER_PERM_CHECK)
+					goto invalid_key;
+				break;
+			case 0:
+				break;
+			}
+		} else if (need_perm != KEY_DEFER_PERM_CHECK) {
+			ret = key_validate(key);
+			if (ret < 0)
+				goto invalid_key;
+		}
+
+		ret = -EIO;
+		if (!(lflags & KEY_LOOKUP_PARTIAL) &&
+		    key_read_state(key) == KEY_IS_UNINSTANTIATED)
+			goto invalid_key;
+	}
+
+	/* check the permissions */
+	ret = key_task_permission(key_ref, ctx.cred, need_perm);
+	if (ret < 0)
+		goto invalid_key;
+
+	key->last_used_at = ktime_get_real_seconds();
+
+error:
+	put_cred(ctx.cred);
+	return key_ref;
+
+invalid_key:
+	key_ref_put(key_ref);
+	key_ref = ERR_PTR(ret);
+	goto error;
+
+	/* if we attempted to install a keyring, then it may have caused new
+	 * creds to be installed */
+reget_creds:
+	put_cred(ctx.cred);
+	goto try_again;
+}
+EXPORT_SYMBOL(lookup_user_key);
+
+/*
+ * Join the named keyring as the session keyring if possible else attempt to
+ * create a new one of that name and join that.
+ *
+ * If the name is NULL, an empty anonymous keyring will be installed as the
+ * session keyring.
+ *
+ * Named session keyrings are joined with a semaphore held to prevent the
+ * keyrings from going away whilst the attempt is made to going them and also
+ * to prevent a race in creating compatible session keyrings.
+ */
+long join_session_keyring(const char *name)
+{
+	const struct cred *old;
+	struct cred *new;
+	struct key *keyring;
+	long ret, serial;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
+	/* if no name is provided, install an anonymous keyring */
+	if (!name) {
+		ret = install_session_keyring_to_cred(new, NULL);
+		if (ret < 0)
+			goto error;
+
+		serial = new->session_keyring->serial;
+		ret = commit_creds(new);
+		if (ret == 0)
+			ret = serial;
+		goto okay;
+	}
+
+	/* allow the user to join or create a named keyring */
+	mutex_lock(&key_session_mutex);
+
+	/* look for an existing keyring of this name */
+	keyring = find_keyring_by_name(name, false);
+	if (PTR_ERR(keyring) == -ENOKEY) {
+		/* not found - try and create a new one */
+		keyring = keyring_alloc(
+			name, old->uid, old->gid, old,
+			KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK,
+			KEY_ALLOC_IN_QUOTA, NULL, NULL);
+		if (IS_ERR(keyring)) {
+			ret = PTR_ERR(keyring);
+			goto error2;
+		}
+	} else if (IS_ERR(keyring)) {
+		ret = PTR_ERR(keyring);
+		goto error2;
+	} else if (keyring == new->session_keyring) {
+		ret = 0;
+		goto error3;
+	}
+
+	/* we've got a keyring - now to install it */
+	ret = install_session_keyring_to_cred(new, keyring);
+	if (ret < 0)
+		goto error3;
+
+	commit_creds(new);
+	mutex_unlock(&key_session_mutex);
+
+	ret = keyring->serial;
+	key_put(keyring);
+okay:
+	return ret;
+
+error3:
+	key_put(keyring);
+error2:
+	mutex_unlock(&key_session_mutex);
+error:
+	abort_creds(new);
+	return ret;
+}
+
+/*
+ * Replace a process's session keyring on behalf of one of its children when
+ * the target  process is about to resume userspace execution.
+ */
+void key_change_session_keyring(struct callback_head *twork)
+{
+	const struct cred *old = current_cred();
+	struct cred *new = container_of(twork, struct cred, rcu);
+
+	if (unlikely(current->flags & PF_EXITING)) {
+		put_cred(new);
+		return;
+	}
+
+	/* If get_ucounts fails more bits are needed in the refcount */
+	if (unlikely(!get_ucounts(old->ucounts))) {
+		WARN_ONCE(1, "In %s get_ucounts failed\n", __func__);
+		put_cred(new);
+		return;
+	}
+
+	new->  uid	= old->  uid;
+	new-> euid	= old-> euid;
+	new-> suid	= old-> suid;
+	new->fsuid	= old->fsuid;
+	new->  gid	= old->  gid;
+	new-> egid	= old-> egid;
+	new-> sgid	= old-> sgid;
+	new->fsgid	= old->fsgid;
+	new->user	= get_uid(old->user);
+	new->ucounts	= old->ucounts;
+	new->user_ns	= get_user_ns(old->user_ns);
+	new->group_info	= get_group_info(old->group_info);
+
+	new->securebits	= old->securebits;
+	new->cap_inheritable	= old->cap_inheritable;
+	new->cap_permitted	= old->cap_permitted;
+	new->cap_effective	= old->cap_effective;
+	new->cap_ambient	= old->cap_ambient;
+	new->cap_bset		= old->cap_bset;
+
+	new->jit_keyring	= old->jit_keyring;
+	new->thread_keyring	= key_get(old->thread_keyring);
+	new->process_keyring	= key_get(old->process_keyring);
+
+	security_transfer_creds(new, old);
+
+	commit_creds(new);
+}
+
+/*
+ * Make sure that root's user and user-session keyrings exist.
+ */
+static int __init init_root_keyring(void)
+{
+	return look_up_user_keyrings(NULL, NULL);
+}
+
+late_initcall(init_root_keyring);

linux-7.2.3/security/keys/request_key.c

@@ -0,0 +1,821 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Request a key from userspace
+ *
+ * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * See Documentation/security/keys/request-key.rst
+ */
+
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/kmod.h>
+#include <linux/err.h>
+#include <linux/keyctl.h>
+#include <linux/slab.h>
+#include <net/net_namespace.h>
+#include "internal.h"
+#include <keys/request_key_auth-type.h>
+
+#define key_negative_timeout	60	/* default timeout on a negative key's existence */
+
+static struct key *check_cached_key(struct keyring_search_context *ctx)
+{
+#ifdef CONFIG_KEYS_REQUEST_CACHE
+	struct key *key = current->cached_requested_key;
+
+	if (key &&
+	    ctx->match_data.cmp(key, &ctx->match_data) &&
+	    !(key->flags & ((1 << KEY_FLAG_INVALIDATED) |
+			    (1 << KEY_FLAG_REVOKED))))
+		return key_get(key);
+#endif
+	return NULL;
+}
+
+static void cache_requested_key(struct key *key)
+{
+#ifdef CONFIG_KEYS_REQUEST_CACHE
+	struct task_struct *t = current;
+
+	/* Do not cache key if it is a kernel thread */
+	if (!(t->flags & PF_KTHREAD)) {
+		key_put(t->cached_requested_key);
+		t->cached_requested_key = key_get(key);
+		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+	}
+#endif
+}
+
+/**
+ * complete_request_key - Complete the construction of a key.
+ * @authkey: The authorisation key.
+ * @error: The success or failute of the construction.
+ *
+ * Complete the attempt to construct a key.  The key will be negated
+ * if an error is indicated.  The authorisation key will be revoked
+ * unconditionally.
+ */
+void complete_request_key(struct key *authkey, int error)
+{
+	struct request_key_auth *rka = get_request_key_auth(authkey);
+	struct key *key = rka->target_key;
+
+	kenter("%d{%d},%d", authkey->serial, key->serial, error);
+
+	if (error < 0)
+		key_negate_and_link(key, key_negative_timeout, NULL, authkey);
+	else
+		key_revoke(authkey);
+}
+EXPORT_SYMBOL(complete_request_key);
+
+/*
+ * Initialise a usermode helper that is going to have a specific session
+ * keyring.
+ *
+ * This is called in context of freshly forked kthread before kernel_execve(),
+ * so we can simply install the desired session_keyring at this point.
+ */
+static int umh_keys_init(struct subprocess_info *info, struct cred *cred)
+{
+	struct key *keyring = info->data;
+
+	return install_session_keyring_to_cred(cred, keyring);
+}
+
+/*
+ * Clean up a usermode helper with session keyring.
+ */
+static void umh_keys_cleanup(struct subprocess_info *info)
+{
+	struct key *keyring = info->data;
+	key_put(keyring);
+}
+
+/*
+ * Call a usermode helper with a specific session keyring.
+ */
+static int call_usermodehelper_keys(const char *path, char **argv, char **envp,
+					struct key *session_keyring, int wait)
+{
+	struct subprocess_info *info;
+
+	info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL,
+					  umh_keys_init, umh_keys_cleanup,
+					  session_keyring);
+	if (!info)
+		return -ENOMEM;
+
+	key_get(session_keyring);
+	return call_usermodehelper_exec(info, wait);
+}
+
+/*
+ * Request userspace finish the construction of a key
+ * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
+ */
+static int call_sbin_request_key(struct key *authkey, void *aux)
+{
+	static char const request_key[] = "/sbin/request-key";
+	struct request_key_auth *rka = get_request_key_auth(authkey);
+	const struct cred *cred = current_cred();
+	key_serial_t prkey, sskey;
+	struct key *key = rka->target_key, *keyring, *session, *user_session;
+	char *argv[9], *envp[3], uid_str[12], gid_str[12];
+	char key_str[12], keyring_str[3][12];
+	char desc[20];
+	int ret, i;
+
+	kenter("{%d},{%d},%s", key->serial, authkey->serial, rka->op);
+
+	ret = look_up_user_keyrings(NULL, &user_session);
+	if (ret < 0)
+		goto error_us;
+
+	/* allocate a new session keyring */
+	sprintf(desc, "_req.%u", key->serial);
+
+	cred = get_current_cred();
+	keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
+				KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
+				KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL);
+	put_cred(cred);
+	if (IS_ERR(keyring)) {
+		ret = PTR_ERR(keyring);
+		goto error_alloc;
+	}
+
+	/* attach the auth key to the session keyring */
+	ret = key_link(keyring, authkey);
+	if (ret < 0)
+		goto error_link;
+
+	/* record the UID and GID */
+	sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid));
+	sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid));
+
+	/* we say which key is under construction */
+	sprintf(key_str, "%d", key->serial);
+
+	/* we specify the process's default keyrings */
+	sprintf(keyring_str[0], "%d",
+		cred->thread_keyring ? cred->thread_keyring->serial : 0);
+
+	prkey = 0;
+	if (cred->process_keyring)
+		prkey = cred->process_keyring->serial;
+	sprintf(keyring_str[1], "%d", prkey);
+
+	session = cred->session_keyring;
+	if (!session)
+		session = user_session;
+	sskey = session->serial;
+
+	sprintf(keyring_str[2], "%d", sskey);
+
+	/* set up a minimal environment */
+	i = 0;
+	envp[i++] = "HOME=/";
+	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+	envp[i] = NULL;
+
+	/* set up the argument list */
+	i = 0;
+	argv[i++] = (char *)request_key;
+	argv[i++] = (char *)rka->op;
+	argv[i++] = key_str;
+	argv[i++] = uid_str;
+	argv[i++] = gid_str;
+	argv[i++] = keyring_str[0];
+	argv[i++] = keyring_str[1];
+	argv[i++] = keyring_str[2];
+	argv[i] = NULL;
+
+	/* do it */
+	ret = call_usermodehelper_keys(request_key, argv, envp, keyring,
+				       UMH_WAIT_PROC);
+	kdebug("usermode -> 0x%x", ret);
+	if (ret >= 0) {
+		/* ret is the exit/wait code */
+		if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) ||
+		    key_validate(key) < 0)
+			ret = -ENOKEY;
+		else
+			/* ignore any errors from userspace if the key was
+			 * instantiated */
+			ret = 0;
+	}
+
+error_link:
+	key_put(keyring);
+
+error_alloc:
+	key_put(user_session);
+error_us:
+	complete_request_key(authkey, ret);
+	kleave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Call out to userspace for key construction.
+ *
+ * Program failure is ignored in favour of key status.
+ */
+static int construct_key(struct key *key, const void *callout_info,
+			 size_t callout_len, void *aux,
+			 struct key *dest_keyring)
+{
+	request_key_actor_t actor;
+	struct key *authkey;
+	int ret;
+
+	kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
+
+	/* allocate an authorisation key */
+	authkey = request_key_auth_new(key, "create", callout_info, callout_len,
+				       dest_keyring);
+	if (IS_ERR(authkey))
+		return PTR_ERR(authkey);
+
+	/* Make the call */
+	actor = call_sbin_request_key;
+	if (key->type->request_key)
+		actor = key->type->request_key;
+
+	ret = actor(authkey, aux);
+
+	/* check that the actor called complete_request_key() prior to
+	 * returning an error */
+	WARN_ON(ret < 0 &&
+		!test_bit(KEY_FLAG_INVALIDATED, &authkey->flags));
+
+	key_put(authkey);
+	kleave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Get the appropriate destination keyring for the request.
+ *
+ * The keyring selected is returned with an extra reference upon it which the
+ * caller must release.
+ */
+static int construct_get_dest_keyring(struct key **_dest_keyring)
+{
+	struct request_key_auth *rka;
+	const struct cred *cred = current_cred();
+	struct key *dest_keyring = *_dest_keyring, *authkey;
+	int ret;
+
+	kenter("%p", dest_keyring);
+
+	/* find the appropriate keyring */
+	if (dest_keyring) {
+		/* the caller supplied one */
+		key_get(dest_keyring);
+	} else {
+		bool do_perm_check = true;
+
+		/* use a default keyring; falling through the cases until we
+		 * find one that we actually have */
+		switch (cred->jit_keyring) {
+		case KEY_REQKEY_DEFL_DEFAULT:
+		case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
+			if (cred->request_key_auth) {
+				authkey = cred->request_key_auth;
+				down_read(&authkey->sem);
+				rka = get_request_key_auth(authkey);
+				if (!test_bit(KEY_FLAG_REVOKED,
+					      &authkey->flags))
+					dest_keyring =
+						key_get(rka->dest_keyring);
+				up_read(&authkey->sem);
+				if (dest_keyring) {
+					do_perm_check = false;
+					break;
+				}
+			}
+
+			fallthrough;
+		case KEY_REQKEY_DEFL_THREAD_KEYRING:
+			dest_keyring = key_get(cred->thread_keyring);
+			if (dest_keyring)
+				break;
+
+			fallthrough;
+		case KEY_REQKEY_DEFL_PROCESS_KEYRING:
+			dest_keyring = key_get(cred->process_keyring);
+			if (dest_keyring)
+				break;
+
+			fallthrough;
+		case KEY_REQKEY_DEFL_SESSION_KEYRING:
+			dest_keyring = key_get(cred->session_keyring);
+
+			if (dest_keyring)
+				break;
+
+			fallthrough;
+		case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
+			ret = look_up_user_keyrings(NULL, &dest_keyring);
+			if (ret < 0)
+				return ret;
+			break;
+
+		case KEY_REQKEY_DEFL_USER_KEYRING:
+			ret = look_up_user_keyrings(&dest_keyring, NULL);
+			if (ret < 0)
+				return ret;
+			break;
+
+		case KEY_REQKEY_DEFL_GROUP_KEYRING:
+		default:
+			return -EINVAL;
+		}
+
+		/*
+		 * Require Write permission on the keyring.  This is essential
+		 * because the default keyring may be the session keyring, and
+		 * joining a keyring only requires Search permission.
+		 *
+		 * However, this check is skipped for the "requestor keyring" so
+		 * that /sbin/request-key can itself use request_key() to add
+		 * keys to the original requestor's destination keyring.
+		 */
+		if (dest_keyring && do_perm_check) {
+			ret = key_permission(make_key_ref(dest_keyring, 1),
+					     KEY_NEED_WRITE);
+			if (ret) {
+				key_put(dest_keyring);
+				return ret;
+			}
+		}
+	}
+
+	*_dest_keyring = dest_keyring;
+	kleave(" [dk %d]", key_serial(dest_keyring));
+	return 0;
+}
+
+/*
+ * Allocate a new key in under-construction state and attempt to link it in to
+ * the requested keyring.
+ *
+ * May return a key that's already under construction instead if there was a
+ * race between two thread calling request_key().
+ */
+static int construct_alloc_key(struct keyring_search_context *ctx,
+			       struct key *dest_keyring,
+			       unsigned long flags,
+			       struct key_user *user,
+			       struct key **_key)
+{
+	struct assoc_array_edit *edit = NULL;
+	struct key *key;
+	key_perm_t perm;
+	key_ref_t key_ref;
+	int ret;
+
+	kenter("%s,%s,,,",
+	       ctx->index_key.type->name, ctx->index_key.description);
+
+	*_key = NULL;
+	mutex_lock(&user->cons_lock);
+
+	perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
+	perm |= KEY_USR_VIEW;
+	if (ctx->index_key.type->read)
+		perm |= KEY_POS_READ;
+	if (ctx->index_key.type == &key_type_keyring ||
+	    ctx->index_key.type->update)
+		perm |= KEY_POS_WRITE;
+
+	key = key_alloc(ctx->index_key.type, ctx->index_key.description,
+			ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred,
+			perm, flags, NULL);
+	if (IS_ERR(key))
+		goto alloc_failed;
+
+	set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
+
+	if (dest_keyring) {
+		ret = __key_link_lock(dest_keyring, &key->index_key);
+		if (ret < 0)
+			goto link_lock_failed;
+	}
+
+	/*
+	 * Attach the key to the destination keyring under lock, but we do need
+	 * to do another check just in case someone beat us to it whilst we
+	 * waited for locks.
+	 *
+	 * The caller might specify a comparison function which looks for keys
+	 * that do not exactly match but are still equivalent from the caller's
+	 * perspective. The __key_link_begin() operation must be done only after
+	 * an actual key is determined.
+	 */
+	mutex_lock(&key_construction_mutex);
+
+	rcu_read_lock();
+	key_ref = search_process_keyrings_rcu(ctx);
+	rcu_read_unlock();
+	if (!IS_ERR(key_ref))
+		goto key_already_present;
+
+	if (dest_keyring) {
+		ret = __key_link_begin(dest_keyring, &key->index_key, &edit);
+		if (ret < 0)
+			goto link_alloc_failed;
+		__key_link(dest_keyring, key, &edit);
+	}
+
+	mutex_unlock(&key_construction_mutex);
+	if (dest_keyring)
+		__key_link_end(dest_keyring, &key->index_key, edit);
+	mutex_unlock(&user->cons_lock);
+	*_key = key;
+	kleave(" = 0 [%d]", key_serial(key));
+	return 0;
+
+	/* the key is now present - we tell the caller that we found it by
+	 * returning -EINPROGRESS  */
+key_already_present:
+	key_put(key);
+	mutex_unlock(&key_construction_mutex);
+	key = key_ref_to_ptr(key_ref);
+	if (dest_keyring) {
+		ret = __key_link_begin(dest_keyring, &key->index_key, &edit);
+		if (ret < 0)
+			goto link_alloc_failed_unlocked;
+		ret = __key_link_check_live_key(dest_keyring, key);
+		if (ret == 0)
+			__key_link(dest_keyring, key, &edit);
+		__key_link_end(dest_keyring, &key->index_key, edit);
+		if (ret < 0)
+			goto link_check_failed;
+	}
+	mutex_unlock(&user->cons_lock);
+	*_key = key;
+	kleave(" = -EINPROGRESS [%d]", key_serial(key));
+	return -EINPROGRESS;
+
+link_check_failed:
+	mutex_unlock(&user->cons_lock);
+	key_put(key);
+	kleave(" = %d [linkcheck]", ret);
+	return ret;
+
+link_alloc_failed:
+	mutex_unlock(&key_construction_mutex);
+link_alloc_failed_unlocked:
+	__key_link_end(dest_keyring, &key->index_key, edit);
+link_lock_failed:
+	mutex_unlock(&user->cons_lock);
+	key_put(key);
+	kleave(" = %d [prelink]", ret);
+	return ret;
+
+alloc_failed:
+	mutex_unlock(&user->cons_lock);
+	kleave(" = %ld", PTR_ERR(key));
+	return PTR_ERR(key);
+}
+
+/*
+ * Commence key construction.
+ */
+static struct key *construct_key_and_link(struct keyring_search_context *ctx,
+					  const char *callout_info,
+					  size_t callout_len,
+					  void *aux,
+					  struct key *dest_keyring,
+					  unsigned long flags)
+{
+	struct key_user *user;
+	struct key *key;
+	int ret;
+
+	kenter("");
+
+	if (ctx->index_key.type == &key_type_keyring)
+		return ERR_PTR(-EPERM);
+
+	ret = construct_get_dest_keyring(&dest_keyring);
+	if (ret)
+		goto error;
+
+	user = key_user_lookup(current_fsuid());
+	if (!user) {
+		ret = -ENOMEM;
+		goto error_put_dest_keyring;
+	}
+
+	ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key);
+	key_user_put(user);
+
+	if (ret == 0) {
+		ret = construct_key(key, callout_info, callout_len, aux,
+				    dest_keyring);
+		if (ret < 0) {
+			kdebug("cons failed");
+			goto construction_failed;
+		}
+	} else if (ret == -EINPROGRESS) {
+		ret = 0;
+	} else {
+		goto error_put_dest_keyring;
+	}
+
+	key_put(dest_keyring);
+	kleave(" = key %d", key_serial(key));
+	return key;
+
+construction_failed:
+	key_negate_and_link(key, key_negative_timeout, NULL, NULL);
+	key_put(key);
+error_put_dest_keyring:
+	key_put(dest_keyring);
+error:
+	kleave(" = %d", ret);
+	return ERR_PTR(ret);
+}
+
+/**
+ * request_key_and_link - Request a key and cache it in a keyring.
+ * @type: The type of key we want.
+ * @description: The searchable description of the key.
+ * @domain_tag: The domain in which the key operates.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ * @dest_keyring: Where to cache the key.
+ * @flags: Flags to key_alloc().
+ *
+ * A key matching the specified criteria (type, description, domain_tag) is
+ * searched for in the process's keyrings and returned with its usage count
+ * incremented if found.  Otherwise, if callout_info is not NULL, a key will be
+ * allocated and some service (probably in userspace) will be asked to
+ * instantiate it.
+ *
+ * If successfully found or created, the key will be linked to the destination
+ * keyring if one is provided.
+ *
+ * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED
+ * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was
+ * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT
+ * if insufficient key quota was available to create a new key; or -ENOMEM if
+ * insufficient memory was available.
+ *
+ * If the returned key was created, then it may still be under construction,
+ * and wait_for_key_construction() should be used to wait for that to complete.
+ */
+struct key *request_key_and_link(struct key_type *type,
+				 const char *description,
+				 struct key_tag *domain_tag,
+				 const void *callout_info,
+				 size_t callout_len,
+				 void *aux,
+				 struct key *dest_keyring,
+				 unsigned long flags)
+{
+	struct keyring_search_context ctx = {
+		.index_key.type		= type,
+		.index_key.domain_tag	= domain_tag,
+		.index_key.description	= description,
+		.index_key.desc_len	= strlen(description),
+		.cred			= current_cred(),
+		.match_data.cmp		= key_default_cmp,
+		.match_data.raw_data	= description,
+		.match_data.lookup_type	= KEYRING_SEARCH_LOOKUP_DIRECT,
+		.flags			= (KEYRING_SEARCH_DO_STATE_CHECK |
+					   KEYRING_SEARCH_SKIP_EXPIRED |
+					   KEYRING_SEARCH_RECURSE),
+	};
+	struct key *key;
+	key_ref_t key_ref;
+	int ret;
+
+	kenter("%s,%s,%p,%zu,%p,%p,%lx",
+	       ctx.index_key.type->name, ctx.index_key.description,
+	       callout_info, callout_len, aux, dest_keyring, flags);
+
+	if (type->match_preparse) {
+		ret = type->match_preparse(&ctx.match_data);
+		if (ret < 0) {
+			key = ERR_PTR(ret);
+			goto error;
+		}
+	}
+
+	key = check_cached_key(&ctx);
+	if (key)
+		goto error_free;
+
+	/* search all the process keyrings for a key */
+	rcu_read_lock();
+	key_ref = search_process_keyrings_rcu(&ctx);
+	rcu_read_unlock();
+
+	if (!IS_ERR(key_ref)) {
+		if (dest_keyring) {
+			ret = key_task_permission(key_ref, current_cred(),
+						  KEY_NEED_LINK);
+			if (ret < 0) {
+				key_ref_put(key_ref);
+				key = ERR_PTR(ret);
+				goto error_free;
+			}
+		}
+
+		key = key_ref_to_ptr(key_ref);
+		if (dest_keyring) {
+			ret = key_link(dest_keyring, key);
+			if (ret < 0) {
+				key_put(key);
+				key = ERR_PTR(ret);
+				goto error_free;
+			}
+		}
+
+		/* Only cache the key on immediate success */
+		cache_requested_key(key);
+	} else if (PTR_ERR(key_ref) != -EAGAIN) {
+		key = ERR_CAST(key_ref);
+	} else  {
+		/* the search failed, but the keyrings were searchable, so we
+		 * should consult userspace if we can */
+		key = ERR_PTR(-ENOKEY);
+		if (!callout_info)
+			goto error_free;
+
+		key = construct_key_and_link(&ctx, callout_info, callout_len,
+					     aux, dest_keyring, flags);
+	}
+
+error_free:
+	if (type->match_free)
+		type->match_free(&ctx.match_data);
+error:
+	kleave(" = %p", key);
+	return key;
+}
+
+/**
+ * wait_for_key_construction - Wait for construction of a key to complete
+ * @key: The key being waited for.
+ * @intr: Whether to wait interruptibly.
+ *
+ * Wait for a key to finish being constructed.
+ *
+ * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY
+ * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was
+ * revoked or expired.
+ */
+int wait_for_key_construction(struct key *key, bool intr)
+{
+	int ret;
+
+	ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT,
+			  intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
+	if (ret)
+		return -ERESTARTSYS;
+	ret = key_read_state(key);
+	if (ret < 0)
+		return ret;
+	return key_validate(key);
+}
+EXPORT_SYMBOL(wait_for_key_construction);
+
+/**
+ * request_key_tag - Request a key and wait for construction
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @domain_tag: The domain in which the key operates.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found, new keys are always allocated in the user's quota,
+ * the callout_info must be a NUL-terminated string and no auxiliary data can
+ * be passed.
+ *
+ * Furthermore, it then works as wait_for_key_construction() to wait for the
+ * completion of keys undergoing construction with a non-interruptible wait.
+ */
+struct key *request_key_tag(struct key_type *type,
+			    const char *description,
+			    struct key_tag *domain_tag,
+			    const char *callout_info)
+{
+	struct key *key;
+	size_t callout_len = 0;
+	int ret;
+
+	if (callout_info)
+		callout_len = strlen(callout_info);
+	key = request_key_and_link(type, description, domain_tag,
+				   callout_info, callout_len,
+				   NULL, NULL, KEY_ALLOC_IN_QUOTA);
+	if (!IS_ERR(key)) {
+		ret = wait_for_key_construction(key, false);
+		if (ret < 0) {
+			key_put(key);
+			return ERR_PTR(ret);
+		}
+	}
+	return key;
+}
+EXPORT_SYMBOL(request_key_tag);
+
+/**
+ * request_key_with_auxdata - Request a key with auxiliary data for the upcaller
+ * @type: The type of key we want.
+ * @description: The searchable description of the key.
+ * @domain_tag: The domain in which the key operates.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found and new keys are always allocated in the user's quota.
+ *
+ * Furthermore, it then works as wait_for_key_construction() to wait for the
+ * completion of keys undergoing construction with a non-interruptible wait.
+ */
+struct key *request_key_with_auxdata(struct key_type *type,
+				     const char *description,
+				     struct key_tag *domain_tag,
+				     const void *callout_info,
+				     size_t callout_len,
+				     void *aux)
+{
+	struct key *key;
+	int ret;
+
+	key = request_key_and_link(type, description, domain_tag,
+				   callout_info, callout_len,
+				   aux, NULL, KEY_ALLOC_IN_QUOTA);
+	if (!IS_ERR(key)) {
+		ret = wait_for_key_construction(key, false);
+		if (ret < 0) {
+			key_put(key);
+			return ERR_PTR(ret);
+		}
+	}
+	return key;
+}
+EXPORT_SYMBOL(request_key_with_auxdata);
+
+/**
+ * request_key_rcu - Request key from RCU-read-locked context
+ * @type: The type of key we want.
+ * @description: The name of the key we want.
+ * @domain_tag: The domain in which the key operates.
+ *
+ * Request a key from a context that we may not sleep in (such as RCU-mode
+ * pathwalk).  Keys under construction are ignored.
+ *
+ * Return a pointer to the found key if successful, -ENOKEY if we couldn't find
+ * a key or some other error if the key found was unsuitable or inaccessible.
+ */
+struct key *request_key_rcu(struct key_type *type,
+			    const char *description,
+			    struct key_tag *domain_tag)
+{
+	struct keyring_search_context ctx = {
+		.index_key.type		= type,
+		.index_key.domain_tag	= domain_tag,
+		.index_key.description	= description,
+		.index_key.desc_len	= strlen(description),
+		.cred			= current_cred(),
+		.match_data.cmp		= key_default_cmp,
+		.match_data.raw_data	= description,
+		.match_data.lookup_type	= KEYRING_SEARCH_LOOKUP_DIRECT,
+		.flags			= (KEYRING_SEARCH_DO_STATE_CHECK |
+					   KEYRING_SEARCH_SKIP_EXPIRED),
+	};
+	struct key *key;
+	key_ref_t key_ref;
+
+	kenter("%s,%s", type->name, description);
+
+	key = check_cached_key(&ctx);
+	if (key)
+		return key;
+
+	/* search all the process keyrings for a key */
+	key_ref = search_process_keyrings_rcu(&ctx);
+	if (IS_ERR(key_ref)) {
+		key = ERR_CAST(key_ref);
+		if (PTR_ERR(key_ref) == -EAGAIN)
+			key = ERR_PTR(-ENOKEY);
+	} else {
+		key = key_ref_to_ptr(key_ref);
+		cache_requested_key(key);
+	}
+
+	kleave(" = %p", key);
+	return key;
+}
+EXPORT_SYMBOL(request_key_rcu);

linux-7.2.3/security/keys/request_key_auth.c

@@ -0,0 +1,312 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Request key authorisation token key definition.
+ *
+ * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * See Documentation/security/keys/request-key.rst
+ */
+
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include "internal.h"
+#include <keys/request_key_auth-type.h>
+
+static int request_key_auth_preparse(struct key_preparsed_payload *);
+static void request_key_auth_free_preparse(struct key_preparsed_payload *);
+static int request_key_auth_instantiate(struct key *,
+					struct key_preparsed_payload *);
+static void request_key_auth_describe(const struct key *, struct seq_file *);
+static void request_key_auth_revoke(struct key *);
+static void request_key_auth_destroy(struct key *);
+static long request_key_auth_read(const struct key *, char *, size_t);
+static void request_key_auth_rcu_disposal(struct rcu_head *);
+
+/*
+ * The request-key authorisation key type definition.
+ */
+struct key_type key_type_request_key_auth = {
+	.name		= ".request_key_auth",
+	.def_datalen	= sizeof(struct request_key_auth),
+	.preparse	= request_key_auth_preparse,
+	.free_preparse	= request_key_auth_free_preparse,
+	.instantiate	= request_key_auth_instantiate,
+	.describe	= request_key_auth_describe,
+	.revoke		= request_key_auth_revoke,
+	.destroy	= request_key_auth_destroy,
+	.read		= request_key_auth_read,
+};
+
+static int request_key_auth_preparse(struct key_preparsed_payload *prep)
+{
+	return 0;
+}
+
+static void request_key_auth_free_preparse(struct key_preparsed_payload *prep)
+{
+}
+
+/*
+ * Instantiate a request-key authorisation key.
+ */
+static int request_key_auth_instantiate(struct key *key,
+					struct key_preparsed_payload *prep)
+{
+	rcu_assign_keypointer(key, (struct request_key_auth *)prep->data);
+	return 0;
+}
+
+/*
+ * Describe an authorisation token.
+ */
+static void request_key_auth_describe(const struct key *key,
+				      struct seq_file *m)
+{
+	struct request_key_auth *rka = dereference_key_rcu(key);
+
+	if (!rka)
+		return;
+
+	seq_puts(m, "key:");
+	seq_puts(m, key->description);
+	if (key_is_positive(key))
+		seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len);
+}
+
+/*
+ * Read the callout_info data (retrieves the callout information).
+ * - the key's semaphore is read-locked
+ */
+static long request_key_auth_read(const struct key *key,
+				  char *buffer, size_t buflen)
+{
+	struct request_key_auth *rka = dereference_key_locked(key);
+	size_t datalen;
+	long ret;
+
+	if (!rka)
+		return -EKEYREVOKED;
+
+	datalen = rka->callout_len;
+	ret = datalen;
+
+	/* we can return the data as is */
+	if (buffer && buflen > 0) {
+		if (buflen > datalen)
+			buflen = datalen;
+
+		memcpy(buffer, rka->callout_info, buflen);
+	}
+
+	return ret;
+}
+
+static void free_request_key_auth(struct request_key_auth *rka)
+{
+	if (!rka)
+		return;
+	key_put(rka->target_key);
+	key_put(rka->dest_keyring);
+	if (rka->cred)
+		put_cred(rka->cred);
+	kfree(rka->callout_info);
+	kfree(rka);
+}
+
+/*
+ * Take a reference to the request-key authorisation payload so callers can
+ * drop authkey->sem before doing operations that may sleep.
+ */
+struct request_key_auth *request_key_auth_get(struct key *authkey)
+{
+	struct request_key_auth *rka;
+
+	down_read(&authkey->sem);
+	rka = dereference_key_locked(authkey);
+	if (rka && !test_bit(KEY_FLAG_REVOKED, &authkey->flags))
+		refcount_inc(&rka->usage);
+	else
+		rka = NULL;
+	up_read(&authkey->sem);
+
+	return rka;
+}
+
+void request_key_auth_put(struct request_key_auth *rka)
+{
+	if (rka && refcount_dec_and_test(&rka->usage))
+		call_rcu(&rka->rcu, request_key_auth_rcu_disposal);
+}
+
+/*
+ * Dispose of the request_key_auth record under RCU conditions
+ */
+static void request_key_auth_rcu_disposal(struct rcu_head *rcu)
+{
+	struct request_key_auth *rka =
+		container_of(rcu, struct request_key_auth, rcu);
+
+	free_request_key_auth(rka);
+}
+
+/*
+ * Handle revocation of an authorisation token key.
+ *
+ * Called with the key sem write-locked.
+ */
+static void request_key_auth_revoke(struct key *key)
+{
+	struct request_key_auth *rka = dereference_key_locked(key);
+
+	kenter("{%d}", key->serial);
+	if (!rka)
+		return;
+	rcu_assign_keypointer(key, NULL);
+	request_key_auth_put(rka);
+}
+
+/*
+ * Destroy an instantiation authorisation token key.
+ */
+static void request_key_auth_destroy(struct key *key)
+{
+	struct request_key_auth *rka = rcu_access_pointer(key->payload.rcu_data0);
+
+	kenter("{%d}", key->serial);
+	if (rka) {
+		rcu_assign_keypointer(key, NULL);
+		request_key_auth_put(rka);
+	}
+}
+
+/*
+ * Create an authorisation token for /sbin/request-key or whoever to gain
+ * access to the caller's security data.
+ */
+struct key *request_key_auth_new(struct key *target, const char *op,
+				 const void *callout_info, size_t callout_len,
+				 struct key *dest_keyring)
+{
+	struct request_key_auth *rka, *irka;
+	const struct cred *cred = current_cred();
+	struct key *authkey = NULL;
+	char desc[20];
+	int ret = -ENOMEM;
+
+	kenter("%d,", target->serial);
+
+	/* allocate a auth record */
+	rka = kzalloc_obj(*rka);
+	if (!rka)
+		goto error;
+	refcount_set(&rka->usage, 1);
+	rka->callout_info = kmemdup(callout_info, callout_len, GFP_KERNEL);
+	if (!rka->callout_info)
+		goto error_free_rka;
+	rka->callout_len = callout_len;
+	strscpy(rka->op, op, sizeof(rka->op));
+
+	/* see if the calling process is already servicing the key request of
+	 * another process */
+	if (cred->request_key_auth) {
+		/* it is - use that instantiation context here too */
+		down_read(&cred->request_key_auth->sem);
+
+		/* if the auth key has been revoked, then the key we're
+		 * servicing is already instantiated */
+		if (test_bit(KEY_FLAG_REVOKED,
+			     &cred->request_key_auth->flags)) {
+			up_read(&cred->request_key_auth->sem);
+			ret = -EKEYREVOKED;
+			goto error_free_rka;
+		}
+
+		irka = cred->request_key_auth->payload.data[0];
+		rka->cred = get_cred(irka->cred);
+		rka->pid = irka->pid;
+
+		up_read(&cred->request_key_auth->sem);
+	}
+	else {
+		/* it isn't - use this process as the context */
+		rka->cred = get_cred(cred);
+		rka->pid = current->pid;
+	}
+
+	rka->target_key = key_get(target);
+	rka->dest_keyring = key_get(dest_keyring);
+
+	/* allocate the auth key */
+	sprintf(desc, "%x", target->serial);
+
+	authkey = key_alloc(&key_type_request_key_auth, desc,
+			    cred->fsuid, cred->fsgid, cred,
+			    KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH | KEY_POS_LINK |
+			    KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA, NULL);
+	if (IS_ERR(authkey)) {
+		ret = PTR_ERR(authkey);
+		goto error_free_rka;
+	}
+
+	/* construct the auth key */
+	ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL);
+	if (ret < 0)
+		goto error_put_authkey;
+
+	kleave(" = {%d,%d}", authkey->serial, refcount_read(&authkey->usage));
+	return authkey;
+
+error_put_authkey:
+	key_put(authkey);
+error_free_rka:
+	free_request_key_auth(rka);
+error:
+	kleave("= %d", ret);
+	return ERR_PTR(ret);
+}
+
+/*
+ * Search the current process's keyrings for the authorisation key for
+ * instantiation of a key.
+ */
+struct key *key_get_instantiation_authkey(key_serial_t target_id)
+{
+	char description[16];
+	struct keyring_search_context ctx = {
+		.index_key.type		= &key_type_request_key_auth,
+		.index_key.description	= description,
+		.cred			= current_cred(),
+		.match_data.cmp		= key_default_cmp,
+		.match_data.raw_data	= description,
+		.match_data.lookup_type	= KEYRING_SEARCH_LOOKUP_DIRECT,
+		.flags			= (KEYRING_SEARCH_DO_STATE_CHECK |
+					   KEYRING_SEARCH_RECURSE),
+	};
+	struct key *authkey;
+	key_ref_t authkey_ref;
+
+	ctx.index_key.desc_len = sprintf(description, "%x", target_id);
+
+	rcu_read_lock();
+	authkey_ref = search_process_keyrings_rcu(&ctx);
+	rcu_read_unlock();
+
+	if (IS_ERR(authkey_ref)) {
+		authkey = ERR_CAST(authkey_ref);
+		if (authkey == ERR_PTR(-EAGAIN))
+			authkey = ERR_PTR(-ENOKEY);
+		goto error;
+	}
+
+	authkey = key_ref_to_ptr(authkey_ref);
+	if (test_bit(KEY_FLAG_REVOKED, &authkey->flags)) {
+		key_put(authkey);
+		authkey = ERR_PTR(-EKEYREVOKED);
+	}
+
+error:
+	return authkey;
+}

linux-7.2.3/security/keys/sysctl.c

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Key management controls
+ *
+ * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/key.h>
+#include <linux/sysctl.h>
+#include "internal.h"
+
+static const struct ctl_table key_sysctls[] = {
+	{
+		.procname = "maxkeys",
+		.data = &key_quota_maxkeys,
+		.maxlen = sizeof(unsigned),
+		.mode = 0644,
+		.proc_handler = proc_dointvec_minmax,
+		.extra1 = (void *) SYSCTL_ONE,
+		.extra2 = (void *) SYSCTL_INT_MAX,
+	},
+	{
+		.procname = "maxbytes",
+		.data = &key_quota_maxbytes,
+		.maxlen = sizeof(unsigned),
+		.mode = 0644,
+		.proc_handler = proc_dointvec_minmax,
+		.extra1 = (void *) SYSCTL_ONE,
+		.extra2 = (void *) SYSCTL_INT_MAX,
+	},
+	{
+		.procname = "root_maxkeys",
+		.data = &key_quota_root_maxkeys,
+		.maxlen = sizeof(unsigned),
+		.mode = 0644,
+		.proc_handler = proc_dointvec_minmax,
+		.extra1 = (void *) SYSCTL_ONE,
+		.extra2 = (void *) SYSCTL_INT_MAX,
+	},
+	{
+		.procname = "root_maxbytes",
+		.data = &key_quota_root_maxbytes,
+		.maxlen = sizeof(unsigned),
+		.mode = 0644,
+		.proc_handler = proc_dointvec_minmax,
+		.extra1 = (void *) SYSCTL_ONE,
+		.extra2 = (void *) SYSCTL_INT_MAX,
+	},
+	{
+		.procname = "gc_delay",
+		.data = &key_gc_delay,
+		.maxlen = sizeof(unsigned),
+		.mode = 0644,
+		.proc_handler = proc_dointvec_minmax,
+		.extra1 = (void *) SYSCTL_ZERO,
+		.extra2 = (void *) SYSCTL_INT_MAX,
+	},
+#ifdef CONFIG_PERSISTENT_KEYRINGS
+	{
+		.procname = "persistent_keyring_expiry",
+		.data = &persistent_keyring_expiry,
+		.maxlen = sizeof(unsigned),
+		.mode = 0644,
+		.proc_handler = proc_dointvec_minmax,
+		.extra1 = (void *) SYSCTL_ZERO,
+		.extra2 = (void *) SYSCTL_INT_MAX,
+	},
+#endif
+};
+
+static int __init init_security_keys_sysctls(void)
+{
+	register_sysctl_init("kernel/keys", key_sysctls);
+	return 0;
+}
+early_initcall(init_security_keys_sysctls);

linux-7.2.3/security/keys/trusted-keys/Kconfig

@@ -0,0 +1,82 @@
+config HAVE_TRUSTED_KEYS
+	bool
+
+config HAVE_TRUSTED_KEYS_DEBUG
+	bool
+
+config TRUSTED_KEYS_DEBUG
+	bool "Debug trusted keys"
+	depends on HAVE_TRUSTED_KEYS_DEBUG
+	default n
+	help
+	  Trusted key backends and core code that support debug traces can
+	  opt-in that feature here. Traces must only use debug level output, as
+	  sensitive data may pass by. In the kernel-command line traces can be
+	  enabled via trusted.dyndbg='+p'.
+
+	  SAFETY: Debug dumps are inactive at runtime until trusted.debug is set
+	  to a true value on the kernel command-line. Use at your utmost
+	  consideration when enabling this feature on a production build. The
+	  general advice is not to do this.
+
+config TRUSTED_KEYS_TPM
+	bool "TPM-based trusted keys"
+	depends on TCG_TPM >= TRUSTED_KEYS
+	default y
+	select HAVE_TRUSTED_KEYS_DEBUG
+	select CRYPTO_HASH_INFO
+	select CRYPTO_LIB_SHA1
+	select CRYPTO_LIB_UTILS
+	select ASN1_ENCODER
+	select OID_REGISTRY
+	select ASN1
+	select HAVE_TRUSTED_KEYS
+	help
+	  Enable use of the Trusted Platform Module (TPM) as trusted key
+	  backend. Trusted keys are random number symmetric keys,
+	  which will be generated and RSA-sealed by the TPM.
+	  The TPM only unseals the keys, if the boot PCRs and other
+	  criteria match.
+
+config TRUSTED_KEYS_TEE
+	bool "TEE-based trusted keys"
+	depends on TEE >= TRUSTED_KEYS
+	default y
+	select HAVE_TRUSTED_KEYS_DEBUG
+	select HAVE_TRUSTED_KEYS
+	help
+	  Enable use of the Trusted Execution Environment (TEE) as trusted
+	  key backend.
+
+config TRUSTED_KEYS_CAAM
+	bool "CAAM-based trusted keys"
+	depends on CRYPTO_DEV_FSL_CAAM_JR >= TRUSTED_KEYS
+	select CRYPTO_DEV_FSL_CAAM_BLOB_GEN
+	default y
+	select HAVE_TRUSTED_KEYS_DEBUG
+	select HAVE_TRUSTED_KEYS
+	help
+	  Enable use of NXP's Cryptographic Accelerator and Assurance Module
+	  (CAAM) as trusted key backend.
+
+config TRUSTED_KEYS_DCP
+	bool "DCP-based trusted keys"
+	depends on CRYPTO_DEV_MXS_DCP >= TRUSTED_KEYS
+	default y
+	select HAVE_TRUSTED_KEYS_DEBUG
+	select HAVE_TRUSTED_KEYS
+	help
+	  Enable use of NXP's DCP (Data Co-Processor) as trusted key backend.
+
+config TRUSTED_KEYS_PKWM
+	bool "PKWM-based trusted keys"
+	depends on PSERIES_PLPKS >= TRUSTED_KEYS
+	default y
+	select HAVE_TRUSTED_KEYS_DEBUG
+	select HAVE_TRUSTED_KEYS
+	help
+	  Enable use of IBM PowerVM Key Wrapping Module (PKWM) as a trusted key backend.
+
+if !HAVE_TRUSTED_KEYS
+	comment "No trust source selected!"
+endif

linux-7.2.3/security/keys/trusted-keys/Makefile

@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for trusted keys
+#
+
+obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
+trusted-y += trusted_core.o
+trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o
+
+$(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h
+trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o
+trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o
+
+trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o
+
+trusted-$(CONFIG_TRUSTED_KEYS_CAAM) += trusted_caam.o
+
+trusted-$(CONFIG_TRUSTED_KEYS_DCP) += trusted_dcp.o
+
+trusted-$(CONFIG_TRUSTED_KEYS_PKWM) += trusted_pkwm.o

linux-7.2.3/security/keys/trusted-keys/tpm2key.asn1

@@ -0,0 +1,11 @@
+---
+--- ASN.1 for TPM 2.0 keys
+---
+
+TPMKey ::= SEQUENCE {
+	type		OBJECT IDENTIFIER ({tpm2_key_type}),
+	emptyAuth	[0] EXPLICIT BOOLEAN OPTIONAL,
+	parent		INTEGER ({tpm2_key_parent}),
+	pubkey		OCTET STRING ({tpm2_key_pub}),
+	privkey		OCTET STRING ({tpm2_key_priv})
+	}

linux-7.2.3/security/keys/trusted-keys/trusted_caam.c

@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
+ * Copyright 2025 NXP
+ */
+
+#include <keys/trusted_caam.h>
+#include <keys/trusted-type.h>
+#include <linux/build_bug.h>
+#include <linux/key-type.h>
+#include <linux/parser.h>
+#include <soc/fsl/caam-blob.h>
+
+static struct caam_blob_priv *blobifier;
+
+#define KEYMOD "SECURE_KEY"
+
+static_assert(MAX_KEY_SIZE + CAAM_BLOB_OVERHEAD <= CAAM_BLOB_MAX_LEN);
+static_assert(MAX_BLOB_SIZE <= CAAM_BLOB_MAX_LEN);
+
+enum {
+	opt_err,
+	opt_key_enc_algo,
+};
+
+static const match_table_t key_tokens = {
+	{opt_key_enc_algo, "key_enc_algo=%s"},
+	{opt_err, NULL}
+};
+
+#ifdef CONFIG_TRUSTED_KEYS_DEBUG
+static inline void dump_options(const struct caam_pkey_info *pkey_info)
+{
+	if (!trusted_debug)
+		return;
+
+	pr_debug("key encryption algo %d\n", pkey_info->key_enc_algo);
+}
+#else
+static inline void dump_options(const struct caam_pkey_info *pkey_info)
+{
+}
+#endif
+
+static int get_pkey_options(char *c,
+			    struct caam_pkey_info *pkey_info)
+{
+	substring_t args[MAX_OPT_ARGS];
+	unsigned long token_mask = 0;
+	u16 key_enc_algo;
+	char *p = c;
+	int token;
+	int res;
+
+	if (!c)
+		return 0;
+
+	while ((p = strsep(&c, " \t"))) {
+		if (*p == '\0' || *p == ' ' || *p == '\t')
+			continue;
+		token = match_token(p, key_tokens, args);
+		if (test_and_set_bit(token, &token_mask))
+			return -EINVAL;
+
+		switch (token) {
+		case opt_key_enc_algo:
+			res = kstrtou16(args[0].from, 16, &key_enc_algo);
+			if (res < 0)
+				return -EINVAL;
+			pkey_info->key_enc_algo = key_enc_algo;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static bool is_key_pkey(char **datablob)
+{
+	char *c = NULL;
+
+	do {
+		/* Second argument onwards,
+		 * determine if tied to HW
+		 */
+		c = strsep(datablob, " \t");
+		if (c && (strcmp(c, "pk") == 0))
+			return true;
+	} while (c);
+
+	return false;
+}
+
+static int trusted_caam_seal(struct trusted_key_payload *p, char *datablob)
+{
+	int ret;
+	struct caam_blob_info info = {
+		.input  = p->key,  .input_len   = p->key_len,
+		.output = p->blob, .output_len  = MAX_BLOB_SIZE,
+		.key_mod = KEYMOD, .key_mod_len = sizeof(KEYMOD) - 1,
+	};
+
+	/*
+	 * If it is to be treated as protected key,
+	 * read next arguments too.
+	 */
+	if (is_key_pkey(&datablob)) {
+		info.pkey_info.plain_key_sz = p->key_len;
+		info.pkey_info.is_pkey = 1;
+		ret = get_pkey_options(datablob, &info.pkey_info);
+		if (ret < 0)
+			return 0;
+		dump_options(&info.pkey_info);
+	}
+
+	ret = caam_encap_blob(blobifier, &info);
+	if (ret)
+		return ret;
+
+	p->blob_len = info.output_len;
+	if (info.pkey_info.is_pkey) {
+		p->key_len = p->blob_len + sizeof(struct caam_pkey_info);
+		memcpy(p->key, &info.pkey_info, sizeof(struct caam_pkey_info));
+		memcpy(p->key + sizeof(struct caam_pkey_info), p->blob, p->blob_len);
+	}
+
+	return 0;
+}
+
+static int trusted_caam_unseal(struct trusted_key_payload *p, char *datablob)
+{
+	int ret;
+	struct caam_blob_info info = {
+		.input   = p->blob,  .input_len  = p->blob_len,
+		.output  = p->key,   .output_len = MAX_KEY_SIZE,
+		.key_mod = KEYMOD,  .key_mod_len = sizeof(KEYMOD) - 1,
+	};
+
+	if (is_key_pkey(&datablob)) {
+		info.pkey_info.plain_key_sz = p->blob_len - CAAM_BLOB_OVERHEAD;
+		info.pkey_info.is_pkey = 1;
+		ret = get_pkey_options(datablob, &info.pkey_info);
+		if (ret < 0)
+			return 0;
+		dump_options(&info.pkey_info);
+
+		p->key_len = p->blob_len + sizeof(struct caam_pkey_info);
+		memcpy(p->key, &info.pkey_info, sizeof(struct caam_pkey_info));
+		memcpy(p->key + sizeof(struct caam_pkey_info), p->blob, p->blob_len);
+
+		return 0;
+	}
+
+	ret = caam_decap_blob(blobifier, &info);
+	if (ret)
+		return ret;
+
+	p->key_len = info.output_len;
+
+	return 0;
+}
+
+static int trusted_caam_init(void)
+{
+	int ret;
+
+	blobifier = caam_blob_gen_init();
+	if (IS_ERR(blobifier))
+		return PTR_ERR(blobifier);
+
+	ret = register_key_type(&key_type_trusted);
+	if (ret)
+		caam_blob_gen_exit(blobifier);
+
+	return ret;
+}
+
+static void trusted_caam_exit(void)
+{
+	unregister_key_type(&key_type_trusted);
+	caam_blob_gen_exit(blobifier);
+}
+
+struct trusted_key_ops trusted_key_caam_ops = {
+	.migratable = 0, /* non-migratable */
+	.init = trusted_caam_init,
+	.seal = trusted_caam_seal,
+	.unseal = trusted_caam_unseal,
+	.exit = trusted_caam_exit,
+};

linux-7.2.3/security/keys/trusted-keys/trusted_core.c

@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2010 IBM Corporation
+ * Copyright (c) 2019-2021, Linaro Limited
+ *
+ * See Documentation/security/keys/trusted-encrypted.rst
+ */
+
+#include <keys/user-type.h>
+#include <keys/trusted-type.h>
+#include <keys/trusted_tee.h>
+#include <keys/trusted_caam.h>
+#include <keys/trusted_dcp.h>
+#include <keys/trusted_tpm.h>
+#include <keys/trusted_pkwm.h>
+#include <linux/capability.h>
+#include <linux/err.h>
+#include <linux/hex.h>
+#include <linux/init.h>
+#include <linux/key-type.h>
+#include <linux/module.h>
+#include <linux/parser.h>
+#include <linux/random.h>
+#include <linux/rcupdate.h>
+#include <linux/slab.h>
+#include <linux/static_call.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+
+static char *trusted_rng = "default";
+module_param_named(rng, trusted_rng, charp, 0);
+MODULE_PARM_DESC(rng, "Select trusted key RNG");
+
+#ifdef CONFIG_TRUSTED_KEYS_DEBUG
+bool trusted_debug;
+module_param_named(debug, trusted_debug, bool, 0);
+MODULE_PARM_DESC(debug, "Enable trusted keys debug traces (default: 0)");
+#endif
+
+static char *trusted_key_source;
+module_param_named(source, trusted_key_source, charp, 0);
+MODULE_PARM_DESC(source, "Select trusted keys source (tpm, tee, caam, dcp or pkwm)");
+
+static const struct trusted_key_source trusted_key_sources[] = {
+#if defined(CONFIG_TRUSTED_KEYS_TPM)
+	{ "tpm", &trusted_key_tpm_ops },
+#endif
+#if defined(CONFIG_TRUSTED_KEYS_TEE)
+	{ "tee", &trusted_key_tee_ops },
+#endif
+#if defined(CONFIG_TRUSTED_KEYS_CAAM)
+	{ "caam", &trusted_key_caam_ops },
+#endif
+#if defined(CONFIG_TRUSTED_KEYS_DCP)
+	{ "dcp", &dcp_trusted_key_ops },
+#endif
+#if defined(CONFIG_TRUSTED_KEYS_PKWM)
+	{ "pkwm", &pkwm_trusted_key_ops },
+#endif
+};
+
+DEFINE_STATIC_CALL_NULL(trusted_key_seal, *trusted_key_sources[0].ops->seal);
+DEFINE_STATIC_CALL_NULL(trusted_key_unseal,
+			*trusted_key_sources[0].ops->unseal);
+DEFINE_STATIC_CALL_NULL(trusted_key_get_random,
+			*trusted_key_sources[0].ops->get_random);
+static void (*trusted_key_exit)(void);
+static unsigned char migratable __ro_after_init;
+
+enum {
+	Opt_err,
+	Opt_new, Opt_load, Opt_update,
+};
+
+static const match_table_t key_tokens = {
+	{Opt_new, "new"},
+	{Opt_load, "load"},
+	{Opt_update, "update"},
+	{Opt_err, NULL}
+};
+
+/*
+ * datablob_parse - parse the keyctl data and fill in the
+ *                  payload structure
+ *
+ * On success returns 0, otherwise -EINVAL.
+ */
+static int datablob_parse(char **datablob, struct trusted_key_payload *p)
+{
+	substring_t args[MAX_OPT_ARGS];
+	long keylen;
+	int ret = -EINVAL;
+	int key_cmd;
+	char *c;
+
+	/* main command */
+	c = strsep(datablob, " \t");
+	if (!c)
+		return -EINVAL;
+	key_cmd = match_token(c, key_tokens, args);
+	switch (key_cmd) {
+	case Opt_new:
+		/* first argument is key size */
+		c = strsep(datablob, " \t");
+		if (!c)
+			return -EINVAL;
+		ret = kstrtol(c, 10, &keylen);
+		if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
+			return -EINVAL;
+		p->key_len = keylen;
+		ret = Opt_new;
+		break;
+	case Opt_load:
+		/* first argument is sealed blob */
+		c = strsep(datablob, " \t");
+		if (!c)
+			return -EINVAL;
+		p->blob_len = strlen(c) / 2;
+		if (p->blob_len > MAX_BLOB_SIZE)
+			return -EINVAL;
+		ret = hex2bin(p->blob, c, p->blob_len);
+		if (ret < 0)
+			return -EINVAL;
+		ret = Opt_load;
+		break;
+	case Opt_update:
+		ret = Opt_update;
+		break;
+	case Opt_err:
+		return -EINVAL;
+	}
+	return ret;
+}
+
+static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
+{
+	struct trusted_key_payload *p = NULL;
+	int ret;
+
+	ret = key_payload_reserve(key, sizeof(*p));
+	if (ret < 0)
+		goto err;
+	p = kzalloc_obj(*p);
+	if (!p)
+		goto err;
+
+	p->migratable = migratable;
+err:
+	return p;
+}
+
+/*
+ * trusted_instantiate - create a new trusted key
+ *
+ * Unseal an existing trusted blob or, for a new key, get a
+ * random key, then seal and create a trusted key-type key,
+ * adding it to the specified keyring.
+ *
+ * On success, return 0. Otherwise return errno.
+ */
+static int trusted_instantiate(struct key *key,
+			       struct key_preparsed_payload *prep)
+{
+	struct trusted_key_payload *payload = NULL;
+	size_t datalen = prep->datalen;
+	char *datablob, *orig_datablob;
+	int ret = 0;
+	int key_cmd;
+	size_t key_len;
+
+	if (datalen == 0 || datalen > 32767 || !prep->data)
+		return -EINVAL;
+
+	orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL);
+	if (!datablob)
+		return -ENOMEM;
+	memcpy(datablob, prep->data, datalen);
+	datablob[datalen] = '\0';
+
+	payload = trusted_payload_alloc(key);
+	if (!payload) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	key_cmd = datablob_parse(&datablob, payload);
+	if (key_cmd < 0) {
+		ret = key_cmd;
+		goto out;
+	}
+
+	dump_payload(payload);
+
+	switch (key_cmd) {
+	case Opt_load:
+		ret = static_call(trusted_key_unseal)(payload, datablob);
+		dump_payload(payload);
+		if (ret < 0)
+			pr_info("key_unseal failed (%d)\n", ret);
+		break;
+	case Opt_new:
+		key_len = payload->key_len;
+		ret = static_call(trusted_key_get_random)(payload->key,
+							  key_len);
+		if (ret < 0)
+			goto out;
+
+		if (ret != key_len) {
+			pr_info("key_create failed (%d)\n", ret);
+			ret = -EIO;
+			goto out;
+		}
+
+		ret = static_call(trusted_key_seal)(payload, datablob);
+		if (ret < 0)
+			pr_info("key_seal failed (%d)\n", ret);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+out:
+	kfree_sensitive(orig_datablob);
+	if (!ret)
+		rcu_assign_keypointer(key, payload);
+	else
+		kfree_sensitive(payload);
+	return ret;
+}
+
+static void trusted_rcu_free(struct rcu_head *rcu)
+{
+	struct trusted_key_payload *p;
+
+	p = container_of(rcu, struct trusted_key_payload, rcu);
+	kfree_sensitive(p);
+}
+
+/*
+ * trusted_update - reseal an existing key with new PCR values
+ */
+static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
+{
+	struct trusted_key_payload *p;
+	struct trusted_key_payload *new_p;
+	size_t datalen = prep->datalen;
+	char *datablob, *orig_datablob;
+	int ret = 0;
+
+	if (key_is_negative(key))
+		return -ENOKEY;
+	p = key->payload.data[0];
+	if (!p->migratable)
+		return -EPERM;
+	if (datalen == 0 || datalen > 32767 || !prep->data)
+		return -EINVAL;
+
+	orig_datablob = datablob = kmalloc(datalen + 1, GFP_KERNEL);
+	if (!datablob)
+		return -ENOMEM;
+
+	new_p = trusted_payload_alloc(key);
+	if (!new_p) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	memcpy(datablob, prep->data, datalen);
+	datablob[datalen] = '\0';
+	ret = datablob_parse(&datablob, new_p);
+	if (ret != Opt_update) {
+		ret = -EINVAL;
+		kfree_sensitive(new_p);
+		goto out;
+	}
+
+	/* copy old key values, and reseal with new pcrs */
+	new_p->migratable = p->migratable;
+	new_p->key_len = p->key_len;
+	memcpy(new_p->key, p->key, p->key_len);
+	dump_payload(p);
+	dump_payload(new_p);
+
+	ret = static_call(trusted_key_seal)(new_p, datablob);
+	if (ret < 0) {
+		pr_info("key_seal failed (%d)\n", ret);
+		kfree_sensitive(new_p);
+		goto out;
+	}
+
+	rcu_assign_keypointer(key, new_p);
+	call_rcu(&p->rcu, trusted_rcu_free);
+out:
+	kfree_sensitive(orig_datablob);
+	return ret;
+}
+
+/*
+ * trusted_read - copy the sealed blob data to userspace in hex.
+ * On success, return to userspace the trusted key datablob size.
+ */
+static long trusted_read(const struct key *key, char *buffer,
+			 size_t buflen)
+{
+	const struct trusted_key_payload *p;
+	char *bufp;
+	int i;
+
+	p = dereference_key_locked(key);
+	if (!p)
+		return -EINVAL;
+
+	if (buffer && buflen >= 2 * p->blob_len) {
+		bufp = buffer;
+		for (i = 0; i < p->blob_len; i++)
+			bufp = hex_byte_pack(bufp, p->blob[i]);
+	}
+	return 2 * p->blob_len;
+}
+
+/*
+ * trusted_destroy - clear and free the key's payload
+ */
+static void trusted_destroy(struct key *key)
+{
+	kfree_sensitive(key->payload.data[0]);
+}
+
+struct key_type key_type_trusted = {
+	.name = "trusted",
+	.instantiate = trusted_instantiate,
+	.update = trusted_update,
+	.destroy = trusted_destroy,
+	.describe = user_describe,
+	.read = trusted_read,
+};
+EXPORT_SYMBOL_GPL(key_type_trusted);
+
+static int kernel_get_random(unsigned char *key, size_t key_len)
+{
+	return get_random_bytes_wait(key, key_len) ?: key_len;
+}
+
+static int __init init_trusted(void)
+{
+	int (*get_random)(unsigned char *key, size_t key_len);
+	int i, ret = 0;
+
+	for (i = 0; i < ARRAY_SIZE(trusted_key_sources); i++) {
+		if (trusted_key_source &&
+		    strncmp(trusted_key_source, trusted_key_sources[i].name,
+			    strlen(trusted_key_sources[i].name)))
+			continue;
+
+		/*
+		 * We always support trusted.rng="kernel" and "default" as
+		 * well as trusted.rng=$trusted.source if the trust source
+		 * defines its own get_random callback.
+		 */
+		get_random = trusted_key_sources[i].ops->get_random;
+		if (trusted_rng && strcmp(trusted_rng, "default")) {
+			if (!strcmp(trusted_rng, "kernel")) {
+				get_random = kernel_get_random;
+			} else if (strcmp(trusted_rng, trusted_key_sources[i].name) ||
+				   !get_random) {
+				pr_warn("Unsupported RNG. Supported: kernel");
+				if (get_random)
+					pr_cont(", %s", trusted_key_sources[i].name);
+				pr_cont(", default\n");
+				return -EINVAL;
+			}
+		}
+
+		if (!get_random)
+			get_random = kernel_get_random;
+
+		ret = trusted_key_sources[i].ops->init();
+		if (!ret) {
+			static_call_update(trusted_key_seal, trusted_key_sources[i].ops->seal);
+			static_call_update(trusted_key_unseal, trusted_key_sources[i].ops->unseal);
+			static_call_update(trusted_key_get_random, get_random);
+
+			trusted_key_exit = trusted_key_sources[i].ops->exit;
+			migratable = trusted_key_sources[i].ops->migratable;
+		}
+
+		if (!ret || ret != -ENODEV)
+			break;
+	}
+
+	/*
+	 * encrypted_keys.ko depends on successful load of this module even if
+	 * trusted key implementation is not found.
+	 */
+	if (ret == -ENODEV)
+		return 0;
+
+	return ret;
+}
+
+static void __exit cleanup_trusted(void)
+{
+	if (trusted_key_exit)
+		(*trusted_key_exit)();
+}
+
+late_initcall(init_trusted);
+module_exit(cleanup_trusted);
+
+MODULE_DESCRIPTION("Trusted Key type");
+MODULE_LICENSE("GPL");

linux-7.2.3/security/keys/trusted-keys/trusted_dcp.c

@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 sigma star gmbh
+ */
+
+#include <crypto/aead.h>
+#include <crypto/aes.h>
+#include <crypto/algapi.h>
+#include <crypto/gcm.h>
+#include <crypto/skcipher.h>
+#include <keys/trusted-type.h>
+#include <linux/key-type.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/random.h>
+#include <linux/scatterlist.h>
+#include <soc/fsl/dcp.h>
+
+#define DCP_BLOB_VERSION 1
+#define DCP_BLOB_AUTHLEN 16
+
+/**
+ * DOC: dcp blob format
+ *
+ * The Data Co-Processor (DCP) provides hardware-bound AES keys using its
+ * AES encryption engine only. It does not provide direct key sealing/unsealing.
+ * To make DCP hardware encryption keys usable as trust source, we define
+ * our own custom format that uses a hardware-bound key to secure the sealing
+ * key stored in the key blob.
+ *
+ * Whenever a new trusted key using DCP is generated, we generate a random 128-bit
+ * blob encryption key (BEK) and 128-bit nonce. The BEK and nonce are used to
+ * encrypt the trusted key payload using AES-128-GCM.
+ *
+ * The BEK itself is encrypted using the hardware-bound key using the DCP's AES
+ * encryption engine with AES-128-ECB. The encrypted BEK, generated nonce,
+ * BEK-encrypted payload and authentication tag make up the blob format together
+ * with a version number, payload length and authentication tag.
+ */
+
+/**
+ * struct dcp_blob_fmt - DCP BLOB format.
+ *
+ * @fmt_version: Format version, currently being %1.
+ * @blob_key: Random AES 128 key which is used to encrypt @payload,
+ *            @blob_key itself is encrypted with OTP or UNIQUE device key in
+ *            AES-128-ECB mode by DCP.
+ * @nonce: Random nonce used for @payload encryption.
+ * @payload_len: Length of the plain text @payload.
+ * @payload: The payload itself, encrypted using AES-128-GCM and @blob_key,
+ *           GCM auth tag of size DCP_BLOB_AUTHLEN is attached at the end of it.
+ *
+ * The total size of a DCP BLOB is sizeof(struct dcp_blob_fmt) + @payload_len +
+ * DCP_BLOB_AUTHLEN.
+ */
+struct dcp_blob_fmt {
+	__u8 fmt_version;
+	__u8 blob_key[AES_KEYSIZE_128];
+	__u8 nonce[AES_KEYSIZE_128];
+	__le32 payload_len;
+	__u8 payload[];
+} __packed;
+
+static bool use_otp_key;
+module_param_named(dcp_use_otp_key, use_otp_key, bool, 0);
+MODULE_PARM_DESC(dcp_use_otp_key, "Use OTP instead of UNIQUE key for sealing");
+
+static bool skip_zk_test;
+module_param_named(dcp_skip_zk_test, skip_zk_test, bool, 0);
+MODULE_PARM_DESC(dcp_skip_zk_test, "Don't test whether device keys are zero'ed");
+
+static size_t calc_blob_len(unsigned int payload_len)
+{
+	return sizeof(struct dcp_blob_fmt) + payload_len + DCP_BLOB_AUTHLEN;
+}
+
+static int do_dcp_crypto(u8 *in, u8 *out, bool do_encrypt)
+{
+	struct skcipher_request *req = NULL;
+	struct scatterlist src_sg, dst_sg;
+	struct crypto_skcipher *tfm;
+	u8 paes_key[DCP_PAES_KEYSIZE];
+	DECLARE_CRYPTO_WAIT(wait);
+	int res = 0;
+
+	if (use_otp_key)
+		paes_key[0] = DCP_PAES_KEY_OTP;
+	else
+		paes_key[0] = DCP_PAES_KEY_UNIQUE;
+
+	tfm = crypto_alloc_skcipher("ecb-paes-dcp", CRYPTO_ALG_INTERNAL,
+				    CRYPTO_ALG_INTERNAL);
+	if (IS_ERR(tfm)) {
+		res = PTR_ERR(tfm);
+		tfm = NULL;
+		goto out;
+	}
+
+	req = skcipher_request_alloc(tfm, GFP_NOFS);
+	if (!req) {
+		res = -ENOMEM;
+		goto out;
+	}
+
+	skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+				      CRYPTO_TFM_REQ_MAY_SLEEP,
+				      crypto_req_done, &wait);
+	res = crypto_skcipher_setkey(tfm, paes_key, sizeof(paes_key));
+	if (res < 0)
+		goto out;
+
+	sg_init_one(&src_sg, in, AES_KEYSIZE_128);
+	sg_init_one(&dst_sg, out, AES_KEYSIZE_128);
+	skcipher_request_set_crypt(req, &src_sg, &dst_sg, AES_KEYSIZE_128,
+				   NULL);
+
+	if (do_encrypt)
+		res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
+	else
+		res = crypto_wait_req(crypto_skcipher_decrypt(req), &wait);
+
+out:
+	skcipher_request_free(req);
+	crypto_free_skcipher(tfm);
+
+	return res;
+}
+
+static int do_aead_crypto(u8 *in, u8 *out, size_t len, u8 *key, u8 *nonce,
+			  bool do_encrypt)
+{
+	struct aead_request *aead_req = NULL;
+	struct scatterlist src_sg, dst_sg;
+	struct crypto_aead *aead;
+	int ret;
+	DECLARE_CRYPTO_WAIT(wait);
+
+	aead = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(aead)) {
+		ret = PTR_ERR(aead);
+		goto out;
+	}
+
+	ret = crypto_aead_setauthsize(aead, DCP_BLOB_AUTHLEN);
+	if (ret < 0) {
+		pr_err("Can't set crypto auth tag len: %d\n", ret);
+		goto free_aead;
+	}
+
+	aead_req = aead_request_alloc(aead, GFP_KERNEL);
+	if (!aead_req) {
+		ret = -ENOMEM;
+		goto free_aead;
+	}
+
+	sg_init_one(&src_sg, in, len);
+	if (do_encrypt) {
+		/*
+		 * If we encrypt our buffer has extra space for the auth tag.
+		 */
+		sg_init_one(&dst_sg, out, len + DCP_BLOB_AUTHLEN);
+	} else {
+		sg_init_one(&dst_sg, out, len);
+	}
+
+	aead_request_set_crypt(aead_req, &src_sg, &dst_sg, len, nonce);
+	aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_SLEEP,
+				  crypto_req_done, &wait);
+	aead_request_set_ad(aead_req, 0);
+
+	if (crypto_aead_setkey(aead, key, AES_KEYSIZE_128)) {
+		pr_err("Can't set crypto AEAD key\n");
+		ret = -EINVAL;
+		goto free_req;
+	}
+
+	if (do_encrypt)
+		ret = crypto_wait_req(crypto_aead_encrypt(aead_req), &wait);
+	else
+		ret = crypto_wait_req(crypto_aead_decrypt(aead_req), &wait);
+
+free_req:
+	aead_request_free(aead_req);
+free_aead:
+	crypto_free_aead(aead);
+out:
+	return ret;
+}
+
+static int decrypt_blob_key(u8 *encrypted_key, u8 *plain_key)
+{
+	return do_dcp_crypto(encrypted_key, plain_key, false);
+}
+
+static int encrypt_blob_key(u8 *plain_key, u8 *encrypted_key)
+{
+	return do_dcp_crypto(plain_key, encrypted_key, true);
+}
+
+static int trusted_dcp_seal(struct trusted_key_payload *p, char *datablob)
+{
+	struct dcp_blob_fmt *b = (struct dcp_blob_fmt *)p->blob;
+	size_t blen;
+	int ret;
+	u8 *plain_blob_key;
+
+	blen = calc_blob_len(p->key_len);
+	if (blen > MAX_BLOB_SIZE)
+		return -E2BIG;
+
+	plain_blob_key = kmalloc(AES_KEYSIZE_128, GFP_KERNEL);
+	if (!plain_blob_key)
+		return -ENOMEM;
+
+	b->fmt_version = DCP_BLOB_VERSION;
+	get_random_bytes(b->nonce, AES_KEYSIZE_128);
+	get_random_bytes(plain_blob_key, AES_KEYSIZE_128);
+
+	ret = do_aead_crypto(p->key, b->payload, p->key_len, plain_blob_key,
+			     b->nonce, true);
+	if (ret) {
+		pr_err("Unable to encrypt blob payload: %i\n", ret);
+		goto out;
+	}
+
+	ret = encrypt_blob_key(plain_blob_key, b->blob_key);
+	if (ret) {
+		pr_err("Unable to encrypt blob key: %i\n", ret);
+		goto out;
+	}
+
+	put_unaligned_le32(p->key_len, &b->payload_len);
+	p->blob_len = blen;
+	ret = 0;
+
+out:
+	memzero_explicit(plain_blob_key, AES_KEYSIZE_128);
+	kfree(plain_blob_key);
+
+	return ret;
+}
+
+static int trusted_dcp_unseal(struct trusted_key_payload *p, char *datablob)
+{
+	struct dcp_blob_fmt *b = (struct dcp_blob_fmt *)p->blob;
+	size_t blen;
+	int ret;
+	u8 *plain_blob_key = NULL;
+
+	if (b->fmt_version != DCP_BLOB_VERSION) {
+		pr_err("DCP blob has bad version: %i, expected %i\n",
+		       b->fmt_version, DCP_BLOB_VERSION);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	p->key_len = le32_to_cpu(b->payload_len);
+	if (p->key_len < MIN_KEY_SIZE || p->key_len > MAX_KEY_SIZE) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	blen = calc_blob_len(p->key_len);
+	if (blen != p->blob_len) {
+		pr_err("DCP blob has bad length: %zu != %u\n", blen,
+		       p->blob_len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	plain_blob_key = kmalloc(AES_KEYSIZE_128, GFP_KERNEL);
+	if (!plain_blob_key) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = decrypt_blob_key(b->blob_key, plain_blob_key);
+	if (ret) {
+		pr_err("Unable to decrypt blob key: %i\n", ret);
+		goto out;
+	}
+
+	ret = do_aead_crypto(b->payload, p->key, p->key_len + DCP_BLOB_AUTHLEN,
+			     plain_blob_key, b->nonce, false);
+	if (ret) {
+		pr_err("Unwrap of DCP payload failed: %i\n", ret);
+		goto out;
+	}
+
+	ret = 0;
+out:
+	if (plain_blob_key) {
+		memzero_explicit(plain_blob_key, AES_KEYSIZE_128);
+		kfree(plain_blob_key);
+	}
+
+	return ret;
+}
+
+static int test_for_zero_key(void)
+{
+	/*
+	 * Encrypting a plaintext of all 0x55 bytes will yield
+	 * this ciphertext in case the DCP test key is used.
+	 */
+	static const u8 bad[] = {0x9a, 0xda, 0xe0, 0x54, 0xf6, 0x3d, 0xfa, 0xff,
+				 0x5e, 0xa1, 0x8e, 0x45, 0xed, 0xf6, 0xea, 0x6f};
+	void *buf = NULL;
+	int ret = 0;
+
+	if (skip_zk_test)
+		goto out;
+
+	buf = kmalloc(AES_BLOCK_SIZE, GFP_KERNEL);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	memset(buf, 0x55, AES_BLOCK_SIZE);
+
+	ret = do_dcp_crypto(buf, buf, true);
+	if (ret)
+		goto out;
+
+	if (memcmp(buf, bad, AES_BLOCK_SIZE) == 0) {
+		pr_warn("Device neither in secure nor trusted mode!\n");
+		ret = -EINVAL;
+	}
+out:
+	kfree(buf);
+	return ret;
+}
+
+static int trusted_dcp_init(void)
+{
+	int ret;
+
+	if (use_otp_key)
+		pr_info("Using DCP OTP key\n");
+
+	ret = test_for_zero_key();
+	if (ret) {
+		pr_warn("Test for zero'ed keys failed: %i\n", ret);
+
+		return -EINVAL;
+	}
+
+	return register_key_type(&key_type_trusted);
+}
+
+static void trusted_dcp_exit(void)
+{
+	unregister_key_type(&key_type_trusted);
+}
+
+struct trusted_key_ops dcp_trusted_key_ops = {
+	.exit = trusted_dcp_exit,
+	.init = trusted_dcp_init,
+	.seal = trusted_dcp_seal,
+	.unseal = trusted_dcp_unseal,
+	.migratable = 0,
+};

linux-7.2.3/security/keys/trusted-keys/trusted_pkwm.c

@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 IBM Corporation, Srish Srinivasan <ssrish@linux.ibm.com>
+ */
+
+#include <keys/trusted_pkwm.h>
+#include <keys/trusted-type.h>
+#include <linux/build_bug.h>
+#include <linux/key-type.h>
+#include <linux/parser.h>
+#include <asm/plpks.h>
+
+enum {
+	Opt_err,
+	Opt_wrap_flags,
+};
+
+static const match_table_t key_tokens = {
+	{Opt_wrap_flags, "wrap_flags=%s"},
+	{Opt_err, NULL}
+};
+
+static int getoptions(char *datablob, struct trusted_key_options *opt)
+{
+	substring_t args[MAX_OPT_ARGS];
+	char *p = datablob;
+	int token;
+	int res;
+	u16 wrap_flags;
+	unsigned long token_mask = 0;
+	struct trusted_pkwm_options *pkwm;
+
+	if (!datablob)
+		return 0;
+
+	pkwm = opt->private;
+
+	while ((p = strsep(&datablob, " \t"))) {
+		if (*p == '\0' || *p == ' ' || *p == '\t')
+			continue;
+
+		token = match_token(p, key_tokens, args);
+		if (test_and_set_bit(token, &token_mask))
+			return -EINVAL;
+
+		switch (token) {
+		case Opt_wrap_flags:
+			res = kstrtou16(args[0].from, 16, &wrap_flags);
+			if (res < 0 || wrap_flags > 2)
+				return -EINVAL;
+			pkwm->wrap_flags = wrap_flags;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static struct trusted_key_options *trusted_options_alloc(void)
+{
+	struct trusted_key_options *options;
+	struct trusted_pkwm_options *pkwm;
+
+	options = kzalloc_obj(*options);
+
+	if (options) {
+		pkwm = kzalloc_obj(*pkwm);
+
+		if (!pkwm) {
+			kfree_sensitive(options);
+			options = NULL;
+		} else {
+			options->private = pkwm;
+		}
+	}
+
+	return options;
+}
+
+static int trusted_pkwm_seal(struct trusted_key_payload *p, char *datablob)
+{
+	struct trusted_key_options *options = NULL;
+	struct trusted_pkwm_options *pkwm = NULL;
+	u8 *input_buf, *output_buf;
+	u32 output_len, input_len;
+	int rc;
+
+	options = trusted_options_alloc();
+
+	if (!options)
+		return -ENOMEM;
+
+	rc = getoptions(datablob, options);
+	if (rc < 0)
+		goto out;
+	dump_options(options);
+
+	input_len = p->key_len;
+	input_buf = kmalloc(ALIGN(input_len, 4096), GFP_KERNEL);
+	if (!input_buf) {
+		pr_err("Input buffer allocation failed. Returning -ENOMEM.");
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	memcpy(input_buf, p->key, p->key_len);
+
+	pkwm = options->private;
+
+	rc = plpks_wrap_object(&input_buf, input_len, pkwm->wrap_flags,
+			       &output_buf, &output_len);
+	if (!rc) {
+		memcpy(p->blob, output_buf, output_len);
+		p->blob_len = output_len;
+		dump_payload(p);
+	} else {
+		pr_err("Wrapping of payload key failed: %d\n", rc);
+	}
+
+	kfree(input_buf);
+	kfree(output_buf);
+
+out:
+	kfree_sensitive(options->private);
+	kfree_sensitive(options);
+	return rc;
+}
+
+static int trusted_pkwm_unseal(struct trusted_key_payload *p, char *datablob)
+{
+	u8 *input_buf, *output_buf;
+	u32 input_len, output_len;
+	int rc;
+
+	input_len = p->blob_len;
+	input_buf = kmalloc(ALIGN(input_len, 4096), GFP_KERNEL);
+	if (!input_buf) {
+		pr_err("Input buffer allocation failed. Returning -ENOMEM.");
+		return -ENOMEM;
+	}
+
+	memcpy(input_buf, p->blob, p->blob_len);
+
+	rc = plpks_unwrap_object(&input_buf, input_len, &output_buf,
+				 &output_len);
+	if (!rc) {
+		memcpy(p->key, output_buf, output_len);
+		p->key_len = output_len;
+		dump_payload(p);
+	} else {
+		pr_err("Unwrapping of payload failed: %d\n", rc);
+	}
+
+	kfree(input_buf);
+	kfree(output_buf);
+
+	return rc;
+}
+
+static int trusted_pkwm_init(void)
+{
+	int ret;
+
+	if (!plpks_wrapping_is_supported()) {
+		pr_err("H_PKS_WRAP_OBJECT interface not supported\n");
+		return -ENODEV;
+	}
+
+	ret = plpks_gen_wrapping_key();
+	if (ret) {
+		pr_err("Failed to generate default wrapping key\n");
+		return -EINVAL;
+	}
+
+	return register_key_type(&key_type_trusted);
+}
+
+static void trusted_pkwm_exit(void)
+{
+	unregister_key_type(&key_type_trusted);
+}
+
+struct trusted_key_ops pkwm_trusted_key_ops = {
+	.migratable = 0, /* non-migratable */
+	.init = trusted_pkwm_init,
+	.seal = trusted_pkwm_seal,
+	.unseal = trusted_pkwm_unseal,
+	.exit = trusted_pkwm_exit,
+};

linux-7.2.3/security/keys/trusted-keys/trusted_tee.c

@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019-2021 Linaro Ltd.
+ *
+ * Author:
+ * Sumit Garg <sumit.garg@linaro.org>
+ */
+
+#include <linux/err.h>
+#include <linux/key-type.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/tee_drv.h>
+#include <linux/uuid.h>
+
+#include <keys/trusted_tee.h>
+
+#define DRIVER_NAME "trusted-key-tee"
+
+/*
+ * Get random data for symmetric key
+ *
+ * [out]     memref[0]        Random data
+ */
+#define TA_CMD_GET_RANDOM	0x0
+
+/*
+ * Seal trusted key using hardware unique key
+ *
+ * [in]      memref[0]        Plain key
+ * [out]     memref[1]        Sealed key datablob
+ */
+#define TA_CMD_SEAL		0x1
+
+/*
+ * Unseal trusted key using hardware unique key
+ *
+ * [in]      memref[0]        Sealed key datablob
+ * [out]     memref[1]        Plain key
+ */
+#define TA_CMD_UNSEAL		0x2
+
+/**
+ * struct trusted_key_tee_private - TEE Trusted key private data
+ * @dev:		TEE based Trusted key device.
+ * @ctx:		TEE context handler.
+ * @session_id:		Trusted key TA session identifier.
+ * @shm_pool:		Memory pool shared with TEE device.
+ */
+struct trusted_key_tee_private {
+	struct device *dev;
+	struct tee_context *ctx;
+	u32 session_id;
+	struct tee_shm *shm_pool;
+};
+
+static struct trusted_key_tee_private pvt_data;
+
+/*
+ * Have the TEE seal(encrypt) the symmetric key
+ */
+static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
+{
+	int ret;
+	struct tee_ioctl_invoke_arg inv_arg;
+	struct tee_param param[4];
+	struct tee_shm *reg_shm = NULL;
+
+	memset(&inv_arg, 0, sizeof(inv_arg));
+	memset(&param, 0, sizeof(param));
+
+	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
+					      sizeof(p->key) + sizeof(p->blob));
+	if (IS_ERR(reg_shm)) {
+		dev_err(pvt_data.dev, "shm register failed\n");
+		return PTR_ERR(reg_shm);
+	}
+
+	inv_arg.func = TA_CMD_SEAL;
+	inv_arg.session = pvt_data.session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[0].u.memref.shm = reg_shm;
+	param[0].u.memref.size = p->key_len;
+	param[0].u.memref.shm_offs = 0;
+	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[1].u.memref.shm = reg_shm;
+	param[1].u.memref.size = sizeof(p->blob);
+	param[1].u.memref.shm_offs = sizeof(p->key);
+
+	ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
+	if ((ret < 0) || (inv_arg.ret != 0)) {
+		dev_err(pvt_data.dev, "TA_CMD_SEAL invoke err: %x\n",
+			inv_arg.ret);
+		ret = -EFAULT;
+	} else {
+		p->blob_len = param[1].u.memref.size;
+	}
+
+	tee_shm_free(reg_shm);
+
+	return ret;
+}
+
+/*
+ * Have the TEE unseal(decrypt) the symmetric key
+ */
+static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
+{
+	int ret;
+	struct tee_ioctl_invoke_arg inv_arg;
+	struct tee_param param[4];
+	struct tee_shm *reg_shm = NULL;
+
+	memset(&inv_arg, 0, sizeof(inv_arg));
+	memset(&param, 0, sizeof(param));
+
+	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, p->key,
+					      sizeof(p->key) + sizeof(p->blob));
+	if (IS_ERR(reg_shm)) {
+		dev_err(pvt_data.dev, "shm register failed\n");
+		return PTR_ERR(reg_shm);
+	}
+
+	inv_arg.func = TA_CMD_UNSEAL;
+	inv_arg.session = pvt_data.session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[0].u.memref.shm = reg_shm;
+	param[0].u.memref.size = p->blob_len;
+	param[0].u.memref.shm_offs = sizeof(p->key);
+	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[1].u.memref.shm = reg_shm;
+	param[1].u.memref.size = sizeof(p->key);
+	param[1].u.memref.shm_offs = 0;
+
+	ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
+	if ((ret < 0) || (inv_arg.ret != 0)) {
+		dev_err(pvt_data.dev, "TA_CMD_UNSEAL invoke err: %x\n",
+			inv_arg.ret);
+		ret = -EFAULT;
+	} else {
+		p->key_len = param[1].u.memref.size;
+	}
+
+	tee_shm_free(reg_shm);
+
+	return ret;
+}
+
+/*
+ * Have the TEE generate random symmetric key
+ */
+static int trusted_tee_get_random(unsigned char *key, size_t key_len)
+{
+	int ret;
+	struct tee_ioctl_invoke_arg inv_arg;
+	struct tee_param param[4];
+	struct tee_shm *reg_shm = NULL;
+
+	memset(&inv_arg, 0, sizeof(inv_arg));
+	memset(&param, 0, sizeof(param));
+
+	reg_shm = tee_shm_register_kernel_buf(pvt_data.ctx, key, key_len);
+	if (IS_ERR(reg_shm)) {
+		dev_err(pvt_data.dev, "key shm register failed\n");
+		return PTR_ERR(reg_shm);
+	}
+
+	inv_arg.func = TA_CMD_GET_RANDOM;
+	inv_arg.session = pvt_data.session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[0].u.memref.shm = reg_shm;
+	param[0].u.memref.size = key_len;
+	param[0].u.memref.shm_offs = 0;
+
+	ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
+	if ((ret < 0) || (inv_arg.ret != 0)) {
+		dev_err(pvt_data.dev, "TA_CMD_GET_RANDOM invoke err: %x\n",
+			inv_arg.ret);
+		ret = -EFAULT;
+	} else {
+		ret = param[0].u.memref.size;
+	}
+
+	tee_shm_free(reg_shm);
+
+	return ret;
+}
+
+static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
+{
+	if (ver->impl_id == TEE_IMPL_ID_OPTEE &&
+	    ver->gen_caps & TEE_GEN_CAP_REG_MEM)
+		return 1;
+	else
+		return 0;
+}
+
+static int trusted_key_probe(struct tee_client_device *rng_device)
+{
+	struct device *dev = &rng_device->dev;
+	int ret;
+	struct tee_ioctl_open_session_arg sess_arg;
+
+	memset(&sess_arg, 0, sizeof(sess_arg));
+
+	pvt_data.ctx = tee_client_open_context(NULL, optee_ctx_match, NULL,
+					       NULL);
+	if (IS_ERR(pvt_data.ctx))
+		return -ENODEV;
+
+	memcpy(sess_arg.uuid, rng_device->id.uuid.b, TEE_IOCTL_UUID_LEN);
+	sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
+	sess_arg.num_params = 0;
+
+	ret = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL);
+	if ((ret < 0) || (sess_arg.ret != 0)) {
+		dev_err(dev, "tee_client_open_session failed, err: %x\n",
+			sess_arg.ret);
+		ret = -EINVAL;
+		goto out_ctx;
+	}
+	pvt_data.session_id = sess_arg.session;
+
+	ret = register_key_type(&key_type_trusted);
+	if (ret < 0)
+		goto out_sess;
+
+	pvt_data.dev = dev;
+
+	return 0;
+
+out_sess:
+	tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
+out_ctx:
+	tee_client_close_context(pvt_data.ctx);
+
+	return ret;
+}
+
+static void trusted_key_remove(struct tee_client_device *dev)
+{
+	unregister_key_type(&key_type_trusted);
+	tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
+	tee_client_close_context(pvt_data.ctx);
+}
+
+static const struct tee_client_device_id trusted_key_id_table[] = {
+	{UUID_INIT(0xf04a0fe7, 0x1f5d, 0x4b9b,
+		   0xab, 0xf7, 0x61, 0x9b, 0x85, 0xb4, 0xce, 0x8c)},
+	{}
+};
+MODULE_DEVICE_TABLE(tee, trusted_key_id_table);
+
+static struct tee_client_driver trusted_key_driver = {
+	.probe		= trusted_key_probe,
+	.remove		= trusted_key_remove,
+	.id_table	= trusted_key_id_table,
+	.driver		= {
+		.name		= DRIVER_NAME,
+	},
+};
+
+static int trusted_tee_init(void)
+{
+	return tee_client_driver_register(&trusted_key_driver);
+}
+
+static void trusted_tee_exit(void)
+{
+	tee_client_driver_unregister(&trusted_key_driver);
+}
+
+struct trusted_key_ops trusted_key_tee_ops = {
+	.migratable = 0, /* non-migratable */
+	.init = trusted_tee_init,
+	.seal = trusted_tee_seal,
+	.unseal = trusted_tee_unseal,
+	.get_random = trusted_tee_get_random,
+	.exit = trusted_tee_exit,
+};

linux-7.2.3/security/keys/trusted-keys/trusted_tpm2.c

@@ -0,0 +1,605 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2004 IBM Corporation
+ * Copyright (C) 2014 Intel Corporation
+ */
+
+#include <linux/asn1_encoder.h>
+#include <linux/oid_registry.h>
+#include <linux/string.h>
+#include <linux/err.h>
+#include <linux/tpm.h>
+#include <linux/tpm_command.h>
+
+#include <keys/trusted-type.h>
+#include <keys/trusted_tpm.h>
+
+#include <linux/unaligned.h>
+
+#include "tpm2key.asn1.h"
+
+static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 };
+
+static int tpm2_key_encode(struct trusted_key_payload *payload,
+			   struct trusted_key_options *options,
+			   u8 *src, u32 len)
+{
+	const int SCRATCH_SIZE = PAGE_SIZE;
+	u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
+	u8 *work = scratch, *work1;
+	u8 *end_work = scratch + SCRATCH_SIZE;
+	u8 *priv, *pub;
+	u16 priv_len, pub_len;
+	int ret;
+
+	priv_len = get_unaligned_be16(src) + 2;
+	priv = src;
+
+	src += priv_len;
+
+	pub_len = get_unaligned_be16(src) + 2;
+	pub = src;
+
+	if (!scratch)
+		return -ENOMEM;
+
+	work = asn1_encode_oid(work, end_work, tpm2key_oid,
+			       asn1_oid_len(tpm2key_oid));
+
+	if (options->blobauth_len == 0) {
+		unsigned char bool[3], *w = bool;
+		/* tag 0 is emptyAuth */
+		w = asn1_encode_boolean(w, w + sizeof(bool), true);
+		if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
+			ret = PTR_ERR(w);
+			goto err;
+		}
+		work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
+	}
+
+	/*
+	 * Assume both octet strings will encode to a 2 byte definite length
+	 *
+	 * Note: For a well behaved TPM, this warning should never
+	 * trigger, so if it does there's something nefarious going on
+	 */
+	if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
+		 "BUG: scratch buffer is too small")) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	work = asn1_encode_integer(work, end_work, options->keyhandle);
+	work = asn1_encode_octet_string(work, end_work, pub, pub_len);
+	work = asn1_encode_octet_string(work, end_work, priv, priv_len);
+
+	work1 = payload->blob;
+	work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
+				     scratch, work - scratch);
+	if (IS_ERR(work1)) {
+		ret = PTR_ERR(work1);
+		pr_err("BUG: ASN.1 encoder failed with %d\n", ret);
+		goto err;
+	}
+
+	kfree(scratch);
+	return work1 - payload->blob;
+
+err:
+	kfree(scratch);
+	return ret;
+}
+
+struct tpm2_key_context {
+	u32 parent;
+	const u8 *pub;
+	u32 pub_len;
+	const u8 *priv;
+	u32 priv_len;
+};
+
+static int tpm2_key_decode(struct trusted_key_payload *payload,
+			   struct trusted_key_options *options,
+			   u8 **buf)
+{
+	int ret;
+	struct tpm2_key_context ctx;
+	u8 *blob;
+
+	memset(&ctx, 0, sizeof(ctx));
+
+	ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, payload->blob,
+			       payload->blob_len);
+	if (ret < 0)
+		return ret;
+
+	if (ctx.priv_len + ctx.pub_len > MAX_BLOB_SIZE)
+		return -EINVAL;
+
+	blob = kmalloc(ctx.priv_len + ctx.pub_len + 4, GFP_KERNEL);
+	if (!blob)
+		return -ENOMEM;
+
+	*buf = blob;
+	options->keyhandle = ctx.parent;
+
+	memcpy(blob, ctx.priv, ctx.priv_len);
+	blob += ctx.priv_len;
+
+	memcpy(blob, ctx.pub, ctx.pub_len);
+
+	return 0;
+}
+
+int tpm2_key_parent(void *context, size_t hdrlen,
+		  unsigned char tag,
+		  const void *value, size_t vlen)
+{
+	struct tpm2_key_context *ctx = context;
+	const u8 *v = value;
+	int i;
+
+	ctx->parent = 0;
+	for (i = 0; i < vlen; i++) {
+		ctx->parent <<= 8;
+		ctx->parent |= v[i];
+	}
+
+	return 0;
+}
+
+int tpm2_key_type(void *context, size_t hdrlen,
+		unsigned char tag,
+		const void *value, size_t vlen)
+{
+	enum OID oid = look_up_OID(value, vlen);
+
+	if (oid != OID_TPMSealedData) {
+		char buffer[50];
+
+		sprint_oid(value, vlen, buffer, sizeof(buffer));
+		pr_debug("OID is \"%s\" which is not TPMSealedData\n",
+			 buffer);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int tpm2_key_pub(void *context, size_t hdrlen,
+	       unsigned char tag,
+	       const void *value, size_t vlen)
+{
+	struct tpm2_key_context *ctx = context;
+
+	ctx->pub = value;
+	ctx->pub_len = vlen;
+
+	return 0;
+}
+
+int tpm2_key_priv(void *context, size_t hdrlen,
+		unsigned char tag,
+		const void *value, size_t vlen)
+{
+	struct tpm2_key_context *ctx = context;
+
+	ctx->priv = value;
+	ctx->priv_len = vlen;
+
+	return 0;
+}
+
+/**
+ * tpm2_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
+ *
+ * @buf: an allocated tpm_buf instance
+ * @session_handle: session handle
+ * @nonce: the session nonce, may be NULL if not used
+ * @nonce_len: the session nonce length, may be 0 if not used
+ * @attributes: the session attributes
+ * @hmac: the session HMAC or password, may be NULL if not used
+ * @hmac_len: the session HMAC or password length, maybe 0 if not used
+ */
+static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
+				 const u8 *nonce, u16 nonce_len,
+				 u8 attributes,
+				 const u8 *hmac, u16 hmac_len)
+{
+	tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
+	tpm_buf_append_u32(buf, session_handle);
+	tpm_buf_append_u16(buf, nonce_len);
+
+	if (nonce && nonce_len)
+		tpm_buf_append(buf, nonce, nonce_len);
+
+	tpm_buf_append_u8(buf, attributes);
+	tpm_buf_append_u16(buf, hmac_len);
+
+	if (hmac && hmac_len)
+		tpm_buf_append(buf, hmac, hmac_len);
+}
+
+/**
+ * tpm2_seal_trusted() - seal the payload of a trusted key
+ *
+ * @chip: TPM chip to use
+ * @payload: the key data in clear and encrypted form
+ * @options: authentication values and other options
+ *
+ * Return: < 0 on error and 0 on success.
+ */
+int tpm2_seal_trusted(struct tpm_chip *chip,
+		      struct trusted_key_payload *payload,
+		      struct trusted_key_options *options)
+{
+	off_t offset = TPM_HEADER_SIZE;
+	struct tpm_buf buf, sized;
+	int blob_len = 0;
+	int hash;
+	u32 flags;
+	int rc;
+
+	hash = tpm2_find_hash_alg(options->hash);
+	if (hash < 0)
+		return hash;
+
+	if (!options->keyhandle)
+		return -EINVAL;
+
+	rc = tpm_try_get_ops(chip);
+	if (rc)
+		return rc;
+
+	rc = tpm2_start_auth_session(chip);
+	if (rc)
+		goto out_put;
+
+	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
+	if (rc) {
+		tpm2_end_auth_session(chip);
+		goto out_put;
+	}
+
+	rc = tpm_buf_init_sized(&sized);
+	if (rc) {
+		tpm_buf_destroy(&buf);
+		tpm2_end_auth_session(chip);
+		goto out_put;
+	}
+
+	rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
+	if (rc)
+		goto out;
+
+	tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_DECRYPT,
+				    options->keyauth, TPM_DIGEST_SIZE);
+
+	/* sensitive */
+	tpm_buf_append_u16(&sized, options->blobauth_len);
+
+	if (options->blobauth_len)
+		tpm_buf_append(&sized, options->blobauth, options->blobauth_len);
+
+	tpm_buf_append_u16(&sized, payload->key_len);
+	tpm_buf_append(&sized, payload->key, payload->key_len);
+	tpm_buf_append(&buf, sized.data, sized.length);
+
+	/* public */
+	tpm_buf_reset_sized(&sized);
+	tpm_buf_append_u16(&sized, TPM_ALG_KEYEDHASH);
+	tpm_buf_append_u16(&sized, hash);
+
+	/* key properties */
+	flags = 0;
+	flags |= options->policydigest_len ? 0 : TPM2_OA_USER_WITH_AUTH;
+	flags |= payload->migratable ? 0 : (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT);
+	tpm_buf_append_u32(&sized, flags);
+
+	/* policy */
+	tpm_buf_append_u16(&sized, options->policydigest_len);
+	if (options->policydigest_len)
+		tpm_buf_append(&sized, options->policydigest, options->policydigest_len);
+
+	/* public parameters */
+	tpm_buf_append_u16(&sized, TPM_ALG_NULL);
+	tpm_buf_append_u16(&sized, 0);
+
+	tpm_buf_append(&buf, sized.data, sized.length);
+
+	/* outside info */
+	tpm_buf_append_u16(&buf, 0);
+
+	/* creation PCR */
+	tpm_buf_append_u32(&buf, 0);
+
+	if (buf.flags & TPM_BUF_OVERFLOW) {
+		rc = -E2BIG;
+		tpm2_end_auth_session(chip);
+		goto out;
+	}
+
+	rc = tpm_buf_fill_hmac_session(chip, &buf);
+	if (rc)
+		goto out;
+
+	rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data");
+	rc = tpm_buf_check_hmac_response(chip, &buf, rc);
+	if (rc)
+		goto out;
+
+	blob_len = tpm_buf_read_u32(&buf, &offset);
+	if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_BOUNDARY_ERROR) {
+		rc = -E2BIG;
+		goto out;
+	}
+	if (buf.length - offset < blob_len) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	blob_len = tpm2_key_encode(payload, options, &buf.data[offset], blob_len);
+	if (blob_len < 0)
+		rc = blob_len;
+
+out:
+	tpm_buf_destroy(&sized);
+	tpm_buf_destroy(&buf);
+
+	if (!rc)
+		payload->blob_len = blob_len;
+
+out_put:
+	tpm_put_ops(chip);
+	return tpm_ret_to_err(rc);
+}
+
+/**
+ * tpm2_load_cmd() - execute a TPM2_Load command
+ *
+ * @chip: TPM chip to use
+ * @payload: the key data in clear and encrypted form
+ * @options: authentication values and other options
+ * @blob_handle: returned blob handle
+ *
+ * Return: 0 on success.
+ *        -E2BIG on wrong payload size.
+ *        -EPERM on tpm error status.
+ *        < 0 error from tpm_send.
+ */
+static int tpm2_load_cmd(struct tpm_chip *chip,
+			 struct trusted_key_payload *payload,
+			 struct trusted_key_options *options,
+			 u32 *blob_handle)
+{
+	u8 *blob_ref __free(kfree) = NULL;
+	struct tpm_buf buf;
+	unsigned int private_len;
+	unsigned int public_len;
+	unsigned int blob_len;
+	u8 *blob, *pub;
+	int rc;
+	u32 attrs;
+
+	rc = tpm2_key_decode(payload, options, &blob);
+	if (rc) {
+		/* old form */
+		blob = payload->blob;
+		payload->old_format = 1;
+	} else {
+		/* Bind for cleanup: */
+		blob_ref = blob;
+	}
+
+	/* new format carries keyhandle but old format doesn't */
+	if (!options->keyhandle)
+		return -EINVAL;
+
+	/* must be big enough for at least the two be16 size counts */
+	if (payload->blob_len < 4)
+		return -EINVAL;
+
+	private_len = get_unaligned_be16(blob);
+
+	/* must be big enough for following public_len */
+	if (private_len + 2 + 2 > (payload->blob_len))
+		return -E2BIG;
+
+	public_len = get_unaligned_be16(blob + 2 + private_len);
+	if (private_len + 2 + public_len + 2 > payload->blob_len)
+		return -E2BIG;
+
+	pub = blob + 2 + private_len + 2;
+	/* key attributes are always at offset 4 */
+	attrs = get_unaligned_be32(pub + 4);
+
+	if ((attrs & (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT)) ==
+	    (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT))
+		payload->migratable = 0;
+	else
+		payload->migratable = 1;
+
+	blob_len = private_len + public_len + 4;
+	if (blob_len > payload->blob_len)
+		return -E2BIG;
+
+	rc = tpm2_start_auth_session(chip);
+	if (rc)
+		return rc;
+
+	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
+	if (rc) {
+		tpm2_end_auth_session(chip);
+		return rc;
+	}
+
+	rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
+	if (rc)
+		goto out;
+
+	tpm_buf_append_hmac_session(chip, &buf, 0, options->keyauth,
+				    TPM_DIGEST_SIZE);
+
+	tpm_buf_append(&buf, blob, blob_len);
+
+	if (buf.flags & TPM_BUF_OVERFLOW) {
+		rc = -E2BIG;
+		tpm2_end_auth_session(chip);
+		goto out;
+	}
+
+	rc = tpm_buf_fill_hmac_session(chip, &buf);
+	if (rc)
+		goto out;
+
+	rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
+	rc = tpm_buf_check_hmac_response(chip, &buf, rc);
+	if (!rc)
+		*blob_handle = be32_to_cpup(
+			(__be32 *) &buf.data[TPM_HEADER_SIZE]);
+
+out:
+	tpm_buf_destroy(&buf);
+
+	return tpm_ret_to_err(rc);
+}
+
+/**
+ * tpm2_unseal_cmd() - execute a TPM2_Unseal command
+ *
+ * @chip: TPM chip to use
+ * @payload: the key data in clear and encrypted form
+ * @options: authentication values and other options
+ * @blob_handle: blob handle
+ *
+ * Return: 0 on success
+ *         -EPERM on tpm error status
+ *         < 0 error from tpm_send
+ */
+static int tpm2_unseal_cmd(struct tpm_chip *chip,
+			   struct trusted_key_payload *payload,
+			   struct trusted_key_options *options,
+			   u32 blob_handle)
+{
+	struct tpm_header *head;
+	struct tpm_buf buf;
+	u16 data_len;
+	int offset;
+	u8 *data;
+	int rc;
+
+	rc = tpm2_start_auth_session(chip);
+	if (rc)
+		return rc;
+
+	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
+	if (rc) {
+		tpm2_end_auth_session(chip);
+		return rc;
+	}
+
+	rc = tpm_buf_append_name(chip, &buf, blob_handle, NULL);
+	if (rc)
+		goto out;
+
+	if (!options->policyhandle) {
+		tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT,
+					    options->blobauth,
+					    options->blobauth_len);
+	} else {
+		/*
+		 * FIXME: The policy session was generated outside the
+		 * kernel so we don't known the nonce and thus can't
+		 * calculate a HMAC on it.  Therefore, the user can
+		 * only really use TPM2_PolicyPassword and we must
+		 * send down the plain text password, which could be
+		 * intercepted.  We can still encrypt the returned
+		 * key, but that's small comfort since the interposer
+		 * could repeat our actions with the exfiltrated
+		 * password.
+		 */
+		tpm2_buf_append_auth(&buf, options->policyhandle,
+				     NULL /* nonce */, 0, 0,
+				     options->blobauth, options->blobauth_len);
+		if (tpm2_chip_auth(chip)) {
+			tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT, NULL, 0);
+		} else  {
+			offset = buf.handles * 4 + TPM_HEADER_SIZE;
+			head = (struct tpm_header *)buf.data;
+			if (tpm_buf_length(&buf) == offset)
+				head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
+		}
+	}
+
+	rc = tpm_buf_fill_hmac_session(chip, &buf);
+	if (rc)
+		goto out;
+
+	rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
+	rc = tpm_buf_check_hmac_response(chip, &buf, rc);
+
+	if (!rc) {
+		data_len = be16_to_cpup(
+			(__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
+		if (data_len < MIN_KEY_SIZE ||  data_len > MAX_KEY_SIZE) {
+			rc = -EFAULT;
+			goto out;
+		}
+
+		if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
+			rc = -EFAULT;
+			goto out;
+		}
+		data = &buf.data[TPM_HEADER_SIZE + 6];
+
+		if (payload->old_format) {
+			/* migratable flag is at the end of the key */
+			memcpy(payload->key, data, data_len - 1);
+			payload->key_len = data_len - 1;
+			payload->migratable = data[data_len - 1];
+		} else {
+			/*
+			 * migratable flag already collected from key
+			 * attributes
+			 */
+			memcpy(payload->key, data, data_len);
+			payload->key_len = data_len;
+		}
+	}
+
+out:
+	tpm_buf_destroy(&buf);
+	return tpm_ret_to_err(rc);
+}
+
+/**
+ * tpm2_unseal_trusted() - unseal the payload of a trusted key
+ *
+ * @chip: TPM chip to use
+ * @payload: the key data in clear and encrypted form
+ * @options: authentication values and other options
+ *
+ * Return: Same as with tpm_send.
+ */
+int tpm2_unseal_trusted(struct tpm_chip *chip,
+			struct trusted_key_payload *payload,
+			struct trusted_key_options *options)
+{
+	u32 blob_handle;
+	int rc;
+
+	rc = tpm_try_get_ops(chip);
+	if (rc)
+		return rc;
+
+	rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
+	if (rc)
+		goto out;
+
+	rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
+	tpm2_flush_context(chip, blob_handle);
+
+out:
+	tpm_put_ops(chip);
+	return tpm_ret_to_err(rc);
+}

linux-7.2.3/security/keys/user_defined.c

@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* user_defined.c: user defined key type
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <linux/err.h>
+#include <keys/user-type.h>
+#include <linux/uaccess.h>
+#include "internal.h"
+
+static int logon_vet_description(const char *desc);
+
+/*
+ * user defined keys take an arbitrary string as the description and an
+ * arbitrary blob of data as the payload
+ */
+struct key_type key_type_user = {
+	.name			= "user",
+	.preparse		= user_preparse,
+	.free_preparse		= user_free_preparse,
+	.instantiate		= generic_key_instantiate,
+	.update			= user_update,
+	.revoke			= user_revoke,
+	.destroy		= user_destroy,
+	.describe		= user_describe,
+	.read			= user_read,
+};
+
+EXPORT_SYMBOL_GPL(key_type_user);
+
+/*
+ * This key type is essentially the same as key_type_user, but it does
+ * not define a .read op. This is suitable for storing username and
+ * password pairs in the keyring that you do not want to be readable
+ * from userspace.
+ */
+struct key_type key_type_logon = {
+	.name			= "logon",
+	.preparse		= user_preparse,
+	.free_preparse		= user_free_preparse,
+	.instantiate		= generic_key_instantiate,
+	.update			= user_update,
+	.revoke			= user_revoke,
+	.destroy		= user_destroy,
+	.describe		= user_describe,
+	.vet_description	= logon_vet_description,
+};
+EXPORT_SYMBOL_GPL(key_type_logon);
+
+/*
+ * Preparse a user defined key payload
+ */
+int user_preparse(struct key_preparsed_payload *prep)
+{
+	struct user_key_payload *upayload;
+	size_t datalen = prep->datalen;
+
+	if (datalen == 0 || datalen > 32767 || !prep->data)
+		return -EINVAL;
+
+	upayload = kmalloc_flex(*upayload, data, datalen);
+	if (!upayload)
+		return -ENOMEM;
+
+	/* attach the data */
+	prep->quotalen = datalen;
+	prep->payload.data[0] = upayload;
+	upayload->datalen = datalen;
+	memcpy(upayload->data, prep->data, datalen);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(user_preparse);
+
+/*
+ * Free a preparse of a user defined key payload
+ */
+void user_free_preparse(struct key_preparsed_payload *prep)
+{
+	kfree_sensitive(prep->payload.data[0]);
+}
+EXPORT_SYMBOL_GPL(user_free_preparse);
+
+static void user_free_payload_rcu(struct rcu_head *head)
+{
+	struct user_key_payload *payload;
+
+	payload = container_of(head, struct user_key_payload, rcu);
+	kfree_sensitive(payload);
+}
+
+/*
+ * update a user defined key
+ * - the key's semaphore is write-locked
+ */
+int user_update(struct key *key, struct key_preparsed_payload *prep)
+{
+	struct user_key_payload *zap = NULL;
+	int ret;
+
+	/* check the quota and attach the new data */
+	ret = key_payload_reserve(key, prep->datalen);
+	if (ret < 0)
+		return ret;
+
+	/* attach the new data, displacing the old */
+	key->expiry = prep->expiry;
+	if (key_is_positive(key))
+		zap = dereference_key_locked(key);
+	rcu_assign_keypointer(key, prep->payload.data[0]);
+	prep->payload.data[0] = NULL;
+
+	if (zap)
+		call_rcu(&zap->rcu, user_free_payload_rcu);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(user_update);
+
+/*
+ * dispose of the links from a revoked keyring
+ * - called with the key sem write-locked
+ */
+void user_revoke(struct key *key)
+{
+	struct user_key_payload *upayload = user_key_payload_locked(key);
+
+	/* clear the quota */
+	key_payload_reserve(key, 0);
+
+	if (upayload) {
+		rcu_assign_keypointer(key, NULL);
+		call_rcu(&upayload->rcu, user_free_payload_rcu);
+	}
+}
+
+EXPORT_SYMBOL(user_revoke);
+
+/*
+ * dispose of the data dangling from the corpse of a user key
+ */
+void user_destroy(struct key *key)
+{
+	struct user_key_payload *upayload = key->payload.data[0];
+
+	kfree_sensitive(upayload);
+}
+
+EXPORT_SYMBOL_GPL(user_destroy);
+
+/*
+ * describe the user key
+ */
+void user_describe(const struct key *key, struct seq_file *m)
+{
+	seq_puts(m, key->description);
+	if (key_is_positive(key))
+		seq_printf(m, ": %u", key->datalen);
+}
+
+EXPORT_SYMBOL_GPL(user_describe);
+
+/*
+ * read the key data
+ * - the key's semaphore is read-locked
+ */
+long user_read(const struct key *key, char *buffer, size_t buflen)
+{
+	const struct user_key_payload *upayload;
+	long ret;
+
+	upayload = user_key_payload_locked(key);
+	ret = upayload->datalen;
+
+	/* we can return the data as is */
+	if (buffer && buflen > 0) {
+		if (buflen > upayload->datalen)
+			buflen = upayload->datalen;
+
+		memcpy(buffer, upayload->data, buflen);
+	}
+
+	return ret;
+}
+
+EXPORT_SYMBOL_GPL(user_read);
+
+/* Vet the description for a "logon" key */
+static int logon_vet_description(const char *desc)
+{
+	char *p;
+
+	/* require a "qualified" description string */
+	p = strchr(desc, ':');
+	if (!p)
+		return -EINVAL;
+
+	/* also reject description with ':' as first char */
+	if (p == desc)
+		return -EINVAL;
+
+	return 0;
+}