diff options
Diffstat (limited to 'ubifs-utils')
| -rw-r--r-- | ubifs-utils/libubifs/auth.c | 534 |
1 files changed, 82 insertions, 452 deletions
diff --git a/ubifs-utils/libubifs/auth.c b/ubifs-utils/libubifs/auth.c index 0d561ec..fab1dba 100644 --- a/ubifs-utils/libubifs/auth.c +++ b/ubifs-utils/libubifs/auth.c @@ -9,13 +9,51 @@ * This file implements various helper functions for UBIFS authentication support */ -#include <linux/verification.h> -#include <crypto/hash.h> -#include <crypto/utils.h> -#include <keys/user-type.h> -#include <keys/asymmetric-type.h> - +#include "linux_err.h" #include "ubifs.h" +#include "sign.h" +#include "defs.h" + +int ubifs_shash_init(const struct ubifs_info *c, + __unused struct shash_desc *desc) +{ + if (ubifs_authenticated(c)) + return hash_digest_init(); + else + return 0; +} + +int ubifs_shash_update(const struct ubifs_info *c, + __unused struct shash_desc *desc, + const void *buf, unsigned int len) +{ + int err = 0; + + if (ubifs_authenticated(c)) { + err = hash_digest_update(buf, len); + if (err < 0) + return err; + } + + return 0; +} + +int ubifs_shash_final(const struct ubifs_info *c, + __unused struct shash_desc *desc, u8 *out) +{ + return ubifs_authenticated(c) ? hash_digest_final(out) : 0; +} + +struct shash_desc *ubifs_hash_get_desc(const struct ubifs_info *c) +{ + int err; + + err = ubifs_shash_init(c, NULL); + if (err) + return ERR_PTR(err); + + return NULL; +} /** * ubifs_node_calc_hash - calculate the hash of a UBIFS node @@ -25,101 +63,47 @@ * * 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) +int __ubifs_node_calc_hash(__unused const struct ubifs_info *c, + const void *node, u8 *hash) { const struct ubifs_ch *ch = node; - return crypto_shash_tfm_digest(c->hash_tfm, node, le32_to_cpu(ch->len), - hash); + return hash_digest(node, le32_to_cpu(ch->len), hash); } /** - * 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) -{ - return crypto_shash_tfm_digest(c->hmac_tfm, hash, c->hash_len, hmac); -} - -/** - * ubifs_prepare_auth_node - Prepare an authentication node - * @c: UBIFS file-system description object + * ubifs_master_node_calc_hash - calculate the hash of a UBIFS master node * @node: the node to calculate a hash for - * @inhash: 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. + * @hash: the returned hash */ -int ubifs_prepare_auth_node(struct ubifs_info *c, void *node, - struct shash_desc *inhash) +int ubifs_master_node_calc_hash(const struct ubifs_info *c, const void *node, + uint8_t *hash) { - struct ubifs_auth_node *auth = node; - u8 hash[UBIFS_HASH_ARR_SZ]; - int err; - - { - SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm); - - hash_desc->tfm = c->hash_tfm; - ubifs_shash_copy_state(c, inhash, hash_desc); - - err = crypto_shash_final(hash_desc, hash); - if (err) - return err; - } - - err = ubifs_hash_calc_hmac(c, hash, auth->hmac); - if (err) - return err; + if (!ubifs_authenticated(c)) + return 0; - auth->ch.node_type = UBIFS_AUTH_NODE; - ubifs_prepare_node(c, auth, ubifs_auth_node_sz(c), 0); - return 0; + return hash_digest(node + sizeof(struct ubifs_ch), + UBIFS_MST_NODE_SZ - sizeof(struct ubifs_ch), hash); } -static struct shash_desc *ubifs_get_desc(const struct ubifs_info *c, - struct crypto_shash *tfm) +int ubifs_sign_superblock_node(struct ubifs_info *c, void *node) { - struct shash_desc *desc; - int err; + int err, len; + struct ubifs_sig_node *sig = node + UBIFS_SB_NODE_SZ; 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; + return 0; - err = crypto_shash_init(desc); - if (err) { - kfree(desc); - return ERR_PTR(err); - } + err = hash_sign_node(c->auth_key_filename, c->auth_cert_filename, node, + &len, sig + 1); + if (err) + return err; - return desc; -} + sig->type = UBIFS_SIGNATURE_TYPE_PKCS7; + sig->len = cpu_to_le32(len); + sig->ch.node_type = UBIFS_SIG_NODE; -/** - * __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); + return 0; } /** @@ -150,103 +134,6 @@ void ubifs_bad_hash(const struct ubifs_info *c, const void *node, const u8 *hash } /** - * __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_sb_verify_signature - verify the signature of a superblock - * @c: UBIFS file-system description object - * @sup: The superblock node - * - * To support offline signed images the superblock can be signed with a - * PKCS#7 signature. The signature is placed directly behind the superblock - * node in an ubifs_sig_node. - * - * Returns 0 when the signature can be successfully verified or a negative - * error code if not. - */ -int ubifs_sb_verify_signature(struct ubifs_info *c, - const struct ubifs_sb_node *sup) -{ - int err; - struct ubifs_scan_leb *sleb; - struct ubifs_scan_node *snod; - const struct ubifs_sig_node *signode; - - sleb = ubifs_scan(c, UBIFS_SB_LNUM, UBIFS_SB_NODE_SZ, c->sbuf, 0); - if (IS_ERR(sleb)) { - err = PTR_ERR(sleb); - return err; - } - - if (sleb->nodes_cnt == 0) { - ubifs_err(c, "Unable to find signature node"); - err = -EINVAL; - goto out_destroy; - } - - snod = list_first_entry(&sleb->nodes, struct ubifs_scan_node, list); - - if (snod->type != UBIFS_SIG_NODE) { - ubifs_err(c, "Signature node is of wrong type"); - err = -EINVAL; - goto out_destroy; - } - - signode = snod->node; - - if (le32_to_cpu(signode->len) > snod->len + sizeof(struct ubifs_sig_node)) { - ubifs_err(c, "invalid signature len %d", le32_to_cpu(signode->len)); - err = -EINVAL; - goto out_destroy; - } - - if (le32_to_cpu(signode->type) != UBIFS_SIGNATURE_TYPE_PKCS7) { - ubifs_err(c, "Signature type %d is not supported\n", - le32_to_cpu(signode->type)); - err = -EINVAL; - goto out_destroy; - } - - err = verify_pkcs7_signature(sup, sizeof(struct ubifs_sb_node), - signode->sig, le32_to_cpu(signode->len), - NULL, VERIFYING_UNSPECIFIED_SIGNATURE, - NULL, NULL); - - if (err) - ubifs_err(c, "Failed to verify signature"); - else - ubifs_msg(c, "Successfully verified super block signature"); - -out_destroy: - ubifs_scan_destroy(sleb); - - return err; -} - -/** * ubifs_init_authentication - initialize UBIFS authentication support * @c: UBIFS file-system description object * @@ -254,292 +141,35 @@ out_destroy: */ 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]; + int err, hash_len, hash_algo; - if (!c->auth_hash_name) { - ubifs_err(c, "authentication hash name needed with authentication"); - return -EINVAL; - } + if (!c->auth_key_filename && !c->auth_cert_filename && !c->hash_algo_name) + return 0; - 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); + if (!c->auth_key_filename) { + ubifs_err(c, "authentication key not given (--auth-key)"); 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, 0); - 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, 0); - 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_hmac; - } - - 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)) { - err = PTR_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; - - 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; + if (!c->hash_algo_name) { + ubifs_err(c, "Hash algorithm not given (--hash-algo)"); + return -EINVAL; } - 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); + err = init_authentication(c->hash_algo_name, &hash_len, &hash_algo); if (err) { - kfree(hmac); + ubifs_err(c, "Init authentication failed"); 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; - - 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; + c->hash_len = hash_len; + c->hash_algo = hash_algo; + c->authenticated = 1; - err = crypto_shash_final(shash, hmac); - if (err) - return err; return 0; } -/* - * ubifs_hmac_zero - test if a HMAC is zero - * @c: UBIFS file-system description object - * @hmac: the HMAC to test - * - * This function tests if a HMAC is zero and returns true if it is - * and false otherwise. - */ -bool ubifs_hmac_zero(struct ubifs_info *c, const u8 *hmac) +void __ubifs_exit_authentication(__unused struct ubifs_info *c) { - return !memchr_inv(hmac, 0, c->hmac_desc_len); + exit_authentication(); } |