diff options
Diffstat (limited to 'fs/ubifs')
| -rw-r--r-- | fs/ubifs/Kconfig | 1 | ||||
| -rw-r--r-- | fs/ubifs/Makefile | 1 | ||||
| -rw-r--r-- | fs/ubifs/auth.c | 502 | ||||
| -rw-r--r-- | fs/ubifs/ubifs.h | 218 |
4 files changed, 722 insertions, 0 deletions
diff --git a/fs/ubifs/Kconfig b/fs/ubifs/Kconfig index bbc78549be4c..853c77579b4e 100644 --- a/fs/ubifs/Kconfig +++ b/fs/ubifs/Kconfig @@ -7,6 +7,7 @@ config UBIFS_FS select CRYPTO if UBIFS_FS_ZLIB select CRYPTO_LZO if UBIFS_FS_LZO select CRYPTO_DEFLATE if UBIFS_FS_ZLIB + select CRYPTO_HASH_INFO depends on MTD_UBI help UBIFS is a file system for flash devices which works on top of UBI. diff --git a/fs/ubifs/Makefile b/fs/ubifs/Makefile index 6197d7e539e4..5f838319c8d5 100644 --- a/fs/ubifs/Makefile +++ b/fs/ubifs/Makefile @@ -8,3 +8,4 @@ ubifs-y += recovery.o ioctl.o lpt_commit.o tnc_misc.o debug.o ubifs-y += misc.o ubifs-$(CONFIG_UBIFS_FS_ENCRYPTION) += crypto.o ubifs-$(CONFIG_UBIFS_FS_XATTR) += xattr.o +ubifs-$(CONFIG_UBIFS_FS_AUTHENTICATION) += auth.o diff --git a/fs/ubifs/auth.c b/fs/ubifs/auth.c new file mode 100644 index 000000000000..124e965a28b3 --- /dev/null +++ b/fs/ubifs/auth.c @@ -0,0 +1,502 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This file is part of UBIFS. + * + * Copyright (C) 2018 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de> + */ + +/* + * This file implements various helper functions for UBIFS authentication support + */ + +#include <linux/crypto.h> +#include <crypto/hash.h> +#include <crypto/sha.h> +#include <crypto/algapi.h> +#include <keys/user-type.h> + +#include "ubifs.h" + +/** + * ubifs_node_calc_hash - calculate the hash of a UBIFS node + * @c: UBIFS file-system description object + * @node: the node to calculate a hash for + * @hash: the returned hash + * + * Returns 0 for success or a negative error code otherwise. + */ +int __ubifs_node_calc_hash(const struct ubifs_info *c, const void *node, + u8 *hash) +{ + const struct ubifs_ch *ch = node; + SHASH_DESC_ON_STACK(shash, c->hash_tfm); + int err; + + shash->tfm = c->hash_tfm; + shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + err = crypto_shash_digest(shash, node, le32_to_cpu(ch->len), hash); + if (err < 0) + return err; + return 0; +} + +/** + * ubifs_hash_calc_hmac - calculate a HMAC from a hash + * @c: UBIFS file-system description object + * @hash: the node to calculate a HMAC for + * @hmac: the returned HMAC + * + * Returns 0 for success or a negative error code otherwise. + */ +static int ubifs_hash_calc_hmac(const struct ubifs_info *c, const u8 *hash, + u8 *hmac) +{ + SHASH_DESC_ON_STACK(shash, c->hmac_tfm); + int err; + + shash->tfm = c->hmac_tfm; + shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + err = crypto_shash_digest(shash, hash, c->hash_len, hmac); + if (err < 0) + return err; + return 0; +} + +/** + * ubifs_prepare_auth_node - Prepare an authentication node + * @c: UBIFS file-system description object + * @node: the node to calculate a hash for + * @hash: input hash of previous nodes + * + * This function prepares an authentication node for writing onto flash. + * It creates a HMAC from the given input hash and writes it to the node. + * + * Returns 0 for success or a negative error code otherwise. + */ +int ubifs_prepare_auth_node(struct ubifs_info *c, void *node, + struct shash_desc *inhash) +{ + SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm); + struct ubifs_auth_node *auth = node; + u8 *hash; + int err; + + hash = kmalloc(crypto_shash_descsize(c->hash_tfm), GFP_NOFS); + if (!hash) + return -ENOMEM; + + hash_desc->tfm = c->hash_tfm; + hash_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + ubifs_shash_copy_state(c, inhash, hash_desc); + + err = crypto_shash_final(hash_desc, hash); + if (err) + goto out; + + err = ubifs_hash_calc_hmac(c, hash, auth->hmac); + if (err) + goto out; + + auth->ch.node_type = UBIFS_AUTH_NODE; + ubifs_prepare_node(c, auth, ubifs_auth_node_sz(c), 0); + + err = 0; +out: + kfree(hash); + + return err; +} + +static struct shash_desc *ubifs_get_desc(const struct ubifs_info *c, + struct crypto_shash *tfm) +{ + struct shash_desc *desc; + int err; + + if (!ubifs_authenticated(c)) + return NULL; + + desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(tfm), GFP_KERNEL); + if (!desc) + return ERR_PTR(-ENOMEM); + + desc->tfm = tfm; + desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + err = crypto_shash_init(desc); + if (err) { + kfree(desc); + return ERR_PTR(err); + } + + return desc; +} + +/** + * __ubifs_hash_get_desc - get a descriptor suitable for hashing a node + * @c: UBIFS file-system description object + * + * This function returns a descriptor suitable for hashing a node. Free after use + * with kfree. + */ +struct shash_desc *__ubifs_hash_get_desc(const struct ubifs_info *c) +{ + return ubifs_get_desc(c, c->hash_tfm); +} + +/** + * __ubifs_shash_final - finalize shash + * @c: UBIFS file-system description object + * @desc: the descriptor + * @out: the output hash + * + * Simple wrapper around crypto_shash_final(), safe to be called with + * disabled authentication. + */ +int __ubifs_shash_final(const struct ubifs_info *c, struct shash_desc *desc, + u8 *out) +{ + if (ubifs_authenticated(c)) + return crypto_shash_final(desc, out); + + return 0; +} + +/** + * ubifs_bad_hash - Report hash mismatches + * @c: UBIFS file-system description object + * @node: the node + * @hash: the expected hash + * @lnum: the LEB @node was read from + * @offs: offset in LEB @node was read from + * + * This function reports a hash mismatch when a node has a different hash than + * expected. + */ +void ubifs_bad_hash(const struct ubifs_info *c, const void *node, const u8 *hash, + int lnum, int offs) +{ + int len = min(c->hash_len, 20); + int cropped = len != c->hash_len; + const char *cont = cropped ? "..." : ""; + + u8 calc[UBIFS_HASH_ARR_SZ]; + + __ubifs_node_calc_hash(c, node, calc); + + ubifs_err(c, "hash mismatch on node at LEB %d:%d", lnum, offs); + ubifs_err(c, "hash expected: %*ph%s", len, hash, cont); + ubifs_err(c, "hash calculated: %*ph%s", len, calc, cont); +} + +/** + * __ubifs_node_check_hash - check the hash of a node against given hash + * @c: UBIFS file-system description object + * @node: the node + * @expected: the expected hash + * + * This function calculates a hash over a node and compares it to the given hash. + * Returns 0 if both hashes are equal or authentication is disabled, otherwise a + * negative error code is returned. + */ +int __ubifs_node_check_hash(const struct ubifs_info *c, const void *node, + const u8 *expected) +{ + u8 calc[UBIFS_HASH_ARR_SZ]; + int err; + + err = __ubifs_node_calc_hash(c, node, calc); + if (err) + return err; + + if (ubifs_check_hash(c, expected, calc)) + return -EPERM; + + return 0; +} + +/** + * ubifs_init_authentication - initialize UBIFS authentication support + * @c: UBIFS file-system description object + * + * This function returns 0 for success or a negative error code otherwise. + */ +int ubifs_init_authentication(struct ubifs_info *c) +{ + struct key *keyring_key; + const struct user_key_payload *ukp; + int err; + char hmac_name[CRYPTO_MAX_ALG_NAME]; + + if (!c->auth_hash_name) { + ubifs_err(c, "authentication hash name needed with authentication"); + return -EINVAL; + } + + c->auth_hash_algo = match_string(hash_algo_name, HASH_ALGO__LAST, + c->auth_hash_name); + if ((int)c->auth_hash_algo < 0) { + ubifs_err(c, "Unknown hash algo %s specified", + c->auth_hash_name); + return -EINVAL; + } + + snprintf(hmac_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", + c->auth_hash_name); + + keyring_key = request_key(&key_type_logon, c->auth_key_name, NULL); + + if (IS_ERR(keyring_key)) { + ubifs_err(c, "Failed to request key: %ld", + PTR_ERR(keyring_key)); + return PTR_ERR(keyring_key); + } + + down_read(&keyring_key->sem); + + if (keyring_key->type != &key_type_logon) { + ubifs_err(c, "key type must be logon"); + err = -ENOKEY; + goto out; + } + + ukp = user_key_payload_locked(keyring_key); + if (!ukp) { + /* key was revoked before we acquired its semaphore */ + err = -EKEYREVOKED; + goto out; + } + + c->hash_tfm = crypto_alloc_shash(c->auth_hash_name, 0, + CRYPTO_ALG_ASYNC); + if (IS_ERR(c->hash_tfm)) { + err = PTR_ERR(c->hash_tfm); + ubifs_err(c, "Can not allocate %s: %d", + c->auth_hash_name, err); + goto out; + } + + c->hash_len = crypto_shash_digestsize(c->hash_tfm); + if (c->hash_len > UBIFS_HASH_ARR_SZ) { + ubifs_err(c, "hash %s is bigger than maximum allowed hash size (%d > %d)", + c->auth_hash_name, c->hash_len, UBIFS_HASH_ARR_SZ); + err = -EINVAL; + goto out_free_hash; + } + + c->hmac_tfm = crypto_alloc_shash(hmac_name, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(c->hmac_tfm)) { + err = PTR_ERR(c->hmac_tfm); + ubifs_err(c, "Can not allocate %s: %d", hmac_name, err); + goto out_free_hash; + } + + c->hmac_desc_len = crypto_shash_digestsize(c->hmac_tfm); + if (c->hmac_desc_len > UBIFS_HMAC_ARR_SZ) { + ubifs_err(c, "hmac %s is bigger than maximum allowed hmac size (%d > %d)", + hmac_name, c->hmac_desc_len, UBIFS_HMAC_ARR_SZ); + err = -EINVAL; + goto out_free_hash; + } + + err = crypto_shash_setkey(c->hmac_tfm, ukp->data, ukp->datalen); + if (err) + goto out_free_hmac; + + c->authenticated = true; + + c->log_hash = ubifs_hash_get_desc(c); + if (IS_ERR(c->log_hash)) + goto out_free_hmac; + + err = 0; + +out_free_hmac: + if (err) + crypto_free_shash(c->hmac_tfm); +out_free_hash: + if (err) + crypto_free_shash(c->hash_tfm); +out: + up_read(&keyring_key->sem); + key_put(keyring_key); + + return err; +} + +/** + * __ubifs_exit_authentication - release resource + * @c: UBIFS file-system description object + * + * This function releases the authentication related resources. + */ +void __ubifs_exit_authentication(struct ubifs_info *c) +{ + if (!ubifs_authenticated(c)) + return; + + crypto_free_shash(c->hmac_tfm); + crypto_free_shash(c->hash_tfm); + kfree(c->log_hash); +} + +/** + * ubifs_node_calc_hmac - calculate the HMAC of a UBIFS node + * @c: UBIFS file-system description object + * @node: the node to insert a HMAC into. + * @len: the length of the node + * @ofs_hmac: the offset in the node where the HMAC is inserted + * @hmac: returned HMAC + * + * This function calculates a HMAC of a UBIFS node. The HMAC is expected to be + * embedded into the node, so this area is not covered by the HMAC. Also not + * covered is the UBIFS_NODE_MAGIC and the CRC of the node. + */ +static int ubifs_node_calc_hmac(const struct ubifs_info *c, const void *node, + int len, int ofs_hmac, void *hmac) +{ + SHASH_DESC_ON_STACK(shash, c->hmac_tfm); + int hmac_len = c->hmac_desc_len; + int err; + + ubifs_assert(c, ofs_hmac > 8); + ubifs_assert(c, ofs_hmac + hmac_len < len); + + shash->tfm = c->hmac_tfm; + shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + err = crypto_shash_init(shash); + if (err) + return err; + + /* behind common node header CRC up to HMAC begin */ + err = crypto_shash_update(shash, node + 8, ofs_hmac - 8); + if (err < 0) + return err; + + /* behind HMAC, if any */ + if (len - ofs_hmac - hmac_len > 0) { + err = crypto_shash_update(shash, node + ofs_hmac + hmac_len, + len - ofs_hmac - hmac_len); + if (err < 0) + return err; + } + + return crypto_shash_final(shash, hmac); +} + +/** + * __ubifs_node_insert_hmac - insert a HMAC into a UBIFS node + * @c: UBIFS file-system description object + * @node: the node to insert a HMAC into. + * @len: the length of the node + * @ofs_hmac: the offset in the node where the HMAC is inserted + * + * This function inserts a HMAC at offset @ofs_hmac into the node given in + * @node. + * + * This function returns 0 for success or a negative error code otherwise. + */ +int __ubifs_node_insert_hmac(const struct ubifs_info *c, void *node, int len, + int ofs_hmac) +{ + return ubifs_node_calc_hmac(c, node, len, ofs_hmac, node + ofs_hmac); +} + +/** + * __ubifs_node_verify_hmac - verify the HMAC of UBIFS node + * @c: UBIFS file-system description object + * @node: the node to insert a HMAC into. + * @len: the length of the node + * @ofs_hmac: the offset in the node where the HMAC is inserted + * + * This function verifies the HMAC at offset @ofs_hmac of the node given in + * @node. Returns 0 if successful or a negative error code otherwise. + */ +int __ubifs_node_verify_hmac(const struct ubifs_info *c, const void *node, + int len, int ofs_hmac) +{ + int hmac_len = c->hmac_desc_len; + u8 *hmac; + int err; + + hmac = kmalloc(hmac_len, GFP_NOFS); + if (!hmac) + return -ENOMEM; + + err = ubifs_node_calc_hmac(c, node, len, ofs_hmac, hmac); + if (err) + return err; + + err = crypto_memneq(hmac, node + ofs_hmac, hmac_len); + + kfree(hmac); + + if (!err) + return 0; + + return -EPERM; +} + +int __ubifs_shash_copy_state(const struct ubifs_info *c, struct shash_desc *src, + struct shash_desc *target) +{ + u8 *state; + int err; + + state = kmalloc(crypto_shash_descsize(src->tfm), GFP_NOFS); + if (!state) + return -ENOMEM; + + err = crypto_shash_export(src, state); + if (err) + goto out; + + err = crypto_shash_import(target, state); + +out: + kfree(state); + + return err; +} + +/** + * ubifs_hmac_wkm - Create a HMAC of the well known message + * @c: UBIFS file-system description object + * @hmac: The HMAC of the well known message + * + * This function creates a HMAC of a well known message. This is used + * to check if the provided key is suitable to authenticate a UBIFS + * image. This is only a convenience to the user to provide a better + * error message when the wrong key is provided. + * + * This function returns 0 for success or a negative error code otherwise. + */ +int ubifs_hmac_wkm(struct ubifs_info *c, u8 *hmac) +{ + SHASH_DESC_ON_STACK(shash, c->hmac_tfm); + int err; + const char well_known_message[] = "UBIFS"; + + if (!ubifs_authenticated(c)) + return 0; + + shash->tfm = c->hmac_tfm; + shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + err = crypto_shash_init(shash); + if (err) + return err; + + err = crypto_shash_update(shash, well_known_message, + sizeof(well_known_message) - 1); + if (err < 0) + return err; + + err = crypto_shash_final(shash, hmac); + if (err) + return err; + return 0; +} diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 0422865661b1..3300f68c4097 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -39,6 +39,9 @@ #include <linux/security.h> #include <linux/xattr.h> #include <linux/random.h> +#include <crypto/hash_info.h> +#include <crypto/hash.h> +#include <crypto/algapi.h> #define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_UBIFS_FS_ENCRYPTION) #include <linux/fscrypt.h> @@ -157,6 +160,14 @@ /* Maximum number of data nodes to bulk-read */ #define UBIFS_MAX_BULK_READ 32 +#ifdef CONFIG_UBIFS_FS_AUTHENTICATION +#define UBIFS_HASH_ARR_SZ UBIFS_MAX_HASH_LEN +#define UBIFS_HMAC_ARR_SZ UBIFS_MAX_HMAC_LEN +#else +#define UBIFS_HASH_ARR_SZ 0 +#define UBIFS_HMAC_ARR_SZ 0 +#endif + /* * Lockdep classes for UBIFS inode @ui_mutex. */ @@ -1029,6 +1040,7 @@ struct ubifs_debug_info; * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc) * @rw_incompat: the media is not R/W compatible * @assert_action: action to take when a ubifs_assert() fails + * @authenticated: flag indigating the FS is mounted in authenticated mode * * @tnc_mutex: protects the Tree Node Cache (TNC), @zroot, @cnext, @enext, and * @calc_idx_sz @@ -1076,6 +1088,7 @@ struct ubifs_debug_info; * @key_hash: direntry key hash function * @key_fmt: key format * @key_len: key length + * @hash_len: The length of the index node hashes * @fanout: fanout of the index tree (number of links per indexing node) * * @min_io_size: minimal input/output unit size @@ -1211,6 +1224,13 @@ struct ubifs_debug_info; * @rp_uid: reserved pool user ID * @rp_gid: reserved pool group ID * + * @hash_tfm: the hash transformation used for hashing nodes + * @hmac_tfm: the HMAC transformation for this filesystem + * @hmac_desc_len: length of the HMAC used for authentication + * @auth_key_name: the authentication key name + * @auth_hash_name: the name of the hash algorithm used for authentication + * @auth_hash_algo: the authentication hash used for this fs + * * @empty: %1 if the UBI device is empty * @need_recovery: %1 if the file-system needs recovery * @replaying: %1 during journal replay @@ -1272,6 +1292,7 @@ struct ubifs_info { unsigned int default_compr:2; unsigned int rw_incompat:1; unsigned int assert_action:2; + unsigned int authenticated:1; struct mutex tnc_mutex; struct ubifs_zbranch zroot; @@ -1316,6 +1337,7 @@ struct ubifs_info { uint32_t (*key_hash)(const char *str, int len); int key_fmt; int key_len; + int hash_len; int fanout; int min_io_size; @@ -1443,6 +1465,13 @@ struct ubifs_info { kuid_t rp_uid; kgid_t rp_gid; + struct crypto_shash *hash_tfm; + struct crypto_shash *hmac_tfm; + int hmac_desc_len; + char *auth_key_name; + char *auth_hash_name; + enum hash_algo auth_hash_algo; + /* The below fields are used only during mounting and re-mounting */ unsigned int empty:1; unsigned int need_recovery:1; @@ -1473,6 +1502,195 @@ extern const struct inode_operations ubifs_dir_inode_operations; extern const struct inode_operations ubifs_symlink_inode_operations; extern struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT]; +/* auth.c */ +static inline int ubifs_authenticated(const struct ubifs_info *c) +{ + return (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) && c->authenticated; +} + +struct shash_desc *__ubifs_hash_get_desc(const struct ubifs_info *c); +static inline struct shash_desc *ubifs_hash_get_desc(const struct ubifs_info *c) +{ + return ubifs_authenticated(c) ? __ubifs_hash_get_desc(c) : NULL; +} + +static inline int ubifs_shash_init(const struct ubifs_info *c, + struct shash_desc *desc) +{ + if (ubifs_authenticated(c)) + return crypto_shash_init(desc); + else + return 0; +} + +static inline int ubifs_shash_update(const struct ubifs_info *c, + struct shash_desc *desc, const void *buf, + unsigned int len) +{ + int err = 0; + + if (ubifs_authenticated(c)) { + err = crypto_shash_update(desc, buf, len); + if (err < 0) + return err; + } + + return 0; +} + +static inline int ubifs_shash_final(const struct ubifs_info *c, + struct shash_desc *desc, u8 *out) +{ + return ubifs_authenticated(c) ? crypto_shash_final(desc, out) : 0; +} + +int __ubifs_node_calc_hash(const struct ubifs_info *c, const void *buf, + u8 *hash); +static inline int ubifs_node_calc_hash(const struct ubifs_info *c, + const void *buf, u8 *hash) +{ + if (ubifs_authenticated(c)) + return __ubifs_node_calc_hash(c, buf, hash); + else + return 0; +} + +int ubifs_prepare_auth_node(struct ubifs_info *c, void *node, + struct shash_desc *inhash); + +/** + * ubifs_check_hash - compare two hashes + * @c: UBIFS file-system description object + * @expected: first hash + * @got: second hash + * + * Compare two hashes @expected and @got. Returns 0 when they are equal, a + * negative error code otherwise. + */ +static inline int ubifs_check_hash(const struct ubifs_info *c, + const u8 *expected, const u8 *got) +{ + return crypto_memneq(expected, got, c->hash_len); +} + +/** + * ubifs_check_hmac - compare two HMACs + * @c: UBIFS file-system description object + * @expected: first HMAC + * @got: second HMAC + * + * Compare two hashes @expected and @got. Returns 0 when they are equal, a + * negative error code otherwise. + */ +static inline int ubifs_check_hmac(const struct ubifs_info *c, + const u8 *expected, const u8 *got) +{ + return crypto_memneq(expected, got, c->hmac_desc_len); +} + +void ubifs_bad_hash(const struct ubifs_info *c, const void *node, + const u8 *hash, int lnum, int offs); + +int __ubifs_node_check_hash(const struct ubifs_info *c, const void *buf, + const u8 *expected); +static inline int ubifs_node_check_hash(const struct ubifs_info *c, + const void *buf, const u8 *expected) +{ + if (ubifs_authenticated(c)) + return __ubifs_node_check_hash(c, buf, expected); + else + return 0; +} + +int ubifs_init_authentication(struct ubifs_info *c); +void __ubifs_exit_authentication(struct ubifs_info *c); +static inline void ubifs_exit_authentication(struct ubifs_info *c) +{ + if (ubifs_authenticated(c)) + __ubifs_exit_authentication(c); +} + +/** + * ubifs_branch_hash - returns a pointer to the hash of a branch + * @c: UBIFS file-system description object + * @br: branch to get the hash from + * + * This returns a pointer to the hash of a branch. Since the key already is a + * dynamically sized object we cannot use a struct member here. + */ +static inline u8 *ubifs_branch_hash(struct ubifs_info *c, + struct ubifs_branch *br) +{ + return (void *)br + sizeof(*br) + c->key_len; +} + +/** + * ubifs_copy_hash - copy a hash + * @c: UBIFS file-system description object + * @from: source hash + * @to: destination hash + * + * With authentication this copies a hash, otherwise does nothing. + */ +static inline void ubifs_copy_hash(const struct ubifs_info *c, const u8 *from, + u8 *to) +{ + if (ubifs_authenticated(c)) + memcpy(to, from, c->hash_len); +} + +int __ubifs_node_insert_hmac(const struct ubifs_info *c, void *buf, + int len, int ofs_hmac); +static inline int ubifs_node_insert_hmac(const struct ubifs_info *c, void *buf, + int len, int ofs_hmac) +{ + if (ubifs_authenticated(c)) + return __ubifs_node_insert_hmac(c, buf, len, ofs_hmac); + else + return 0; +} + +int __ubifs_node_verify_hmac(const struct ubifs_info *c, const void *buf, + int len, int ofs_hmac); +static inline int ubifs_node_verify_hmac(const struct ubifs_info *c, + const void *buf, int len, int ofs_hmac) +{ + if (ubifs_authenticated(c)) + return __ubifs_node_verify_hmac(c, buf, len, ofs_hmac); + else + return 0; +} + +/** + * ubifs_auth_node_sz - returns the size of an authentication node + * @c: UBIFS file-system description object + * + * This function returns the size of an authentication node which can + * be 0 for unauthenticated filesystems or the real size of an auth node + * authentication is enabled. + */ +static inline int ubifs_auth_node_sz(const struct ubifs_info *c) +{ + if (ubifs_authenticated(c)) + return sizeof(struct ubifs_auth_node) + c->hmac_desc_len; + else + return 0; +} + +int ubifs_hmac_wkm(struct ubifs_info *c, u8 *hmac); + +int __ubifs_shash_copy_state(const struct ubifs_info *c, struct shash_desc *src, + struct shash_desc *target); +static inline int ubifs_shash_copy_state(const struct ubifs_info *c, + struct shash_desc *src, + struct shash_desc *target) +{ + if (ubifs_authenticated(c)) + return __ubifs_shash_copy_state(c, src, target); + else + return 0; +} + /* io.c */ void ubifs_ro_mode(struct ubifs_info *c, int err); int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs, |