1 // SPDX-License-Identifier: GPL-2.0
5  * Copyright (C) 2018 Pengutronix, Sascha Hauer <[email protected]>
15 #include <keys/user-type.h>
16 #include <keys/asymmetric-type.h>
21  * __ubifs_node_calc_hash - calculate the hash of a UBIFS node
22  * @c: UBIFS file-system description object
23  * @node: the node to calculate a hash for
26  * Returns 0 for success or a negative error code otherwise.
28 int __ubifs_node_calc_hash(const struct ubifs_info *c, const void *node,  in __ubifs_node_calc_hash()  argument
33 	return crypto_shash_tfm_digest(c->hash_tfm, node, le32_to_cpu(ch->len),  in __ubifs_node_calc_hash()
38  * ubifs_hash_calc_hmac - calculate a HMAC from a hash
39  * @c: UBIFS file-system description object
40  * @hash: the node to calculate a HMAC for
43  * Returns 0 for success or a negative error code otherwise.
45 static int ubifs_hash_calc_hmac(const struct ubifs_info *c, const u8 *hash,  in ubifs_hash_calc_hmac()  argument
48 	return crypto_shash_tfm_digest(c->hmac_tfm, hash, c->hash_len, hmac);  in ubifs_hash_calc_hmac()
52  * ubifs_prepare_auth_node - Prepare an authentication node
53  * @c: UBIFS file-system description object
54  * @node: the node to calculate a hash for
58  * It creates a HMAC from the given input hash and writes it to the node.
60  * Returns 0 for success or a negative error code otherwise.
62 int ubifs_prepare_auth_node(struct ubifs_info *c, void *node,  in ubifs_prepare_auth_node()  argument
70 		SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm);  in ubifs_prepare_auth_node()
72 		hash_desc->tfm = c->hash_tfm;  in ubifs_prepare_auth_node()
73 		ubifs_shash_copy_state(c, inhash, hash_desc);  in ubifs_prepare_auth_node()
80 	err = ubifs_hash_calc_hmac(c, hash, auth->hmac);  in ubifs_prepare_auth_node()
84 	auth->ch.node_type = UBIFS_AUTH_NODE;  in ubifs_prepare_auth_node()
85 	ubifs_prepare_node(c, auth, ubifs_auth_node_sz(c), 0);  in ubifs_prepare_auth_node()
89 static struct shash_desc *ubifs_get_desc(const struct ubifs_info *c,  in ubifs_get_desc()  argument
95 	if (!ubifs_authenticated(c))  in ubifs_get_desc()
100 		return ERR_PTR(-ENOMEM);  in ubifs_get_desc()
102 	desc->tfm = tfm;  in ubifs_get_desc()
114  * __ubifs_hash_get_desc - get a descriptor suitable for hashing a node
115  * @c: UBIFS file-system description object
117  * This function returns a descriptor suitable for hashing a node. Free after use
120 struct shash_desc *__ubifs_hash_get_desc(const struct ubifs_info *c)  in __ubifs_hash_get_desc()  argument
122 	return ubifs_get_desc(c, c->hash_tfm);  in __ubifs_hash_get_desc()
126  * ubifs_bad_hash - Report hash mismatches
127  * @c: UBIFS file-system description object
133  * This function reports a hash mismatch when a node has a different hash than
136 void ubifs_bad_hash(const struct ubifs_info *c, const void *node, const u8 *hash,  in ubifs_bad_hash()  argument
139 	int len = min(c->hash_len, 20);  in ubifs_bad_hash()
140 	int cropped = len != c->hash_len;  in ubifs_bad_hash()
145 	__ubifs_node_calc_hash(c, node, calc);  in ubifs_bad_hash()
147 	ubifs_err(c, "hash mismatch on node at LEB %d:%d", lnum, offs);  in ubifs_bad_hash()
148 	ubifs_err(c, "hash expected:   %*ph%s", len, hash, cont);  in ubifs_bad_hash()
149 	ubifs_err(c, "hash calculated: %*ph%s", len, calc, cont);  in ubifs_bad_hash()
153  * __ubifs_node_check_hash - check the hash of a node against given hash
154  * @c: UBIFS file-system description object
158  * This function calculates a hash over a node and compares it to the given hash.
159  * Returns 0 if both hashes are equal or authentication is disabled, otherwise a
162 int __ubifs_node_check_hash(const struct ubifs_info *c, const void *node,  in __ubifs_node_check_hash()  argument
168 	err = __ubifs_node_calc_hash(c, node, calc);  in __ubifs_node_check_hash()
172 	if (ubifs_check_hash(c, expected, calc))  in __ubifs_node_check_hash()
173 		return -EPERM;  in __ubifs_node_check_hash()
179  * ubifs_sb_verify_signature - verify the signature of a superblock
180  * @c: UBIFS file-system description object
183  * To support offline signed images the superblock can be signed with a
187  * Returns 0 when the signature can be successfully verified or a negative
190 int ubifs_sb_verify_signature(struct ubifs_info *c,  in ubifs_sb_verify_signature()  argument
198 	sleb = ubifs_scan(c, UBIFS_SB_LNUM, UBIFS_SB_NODE_SZ, c->sbuf, 0);  in ubifs_sb_verify_signature()
204 	if (sleb->nodes_cnt == 0) {  in ubifs_sb_verify_signature()
205 		ubifs_err(c, "Unable to find signature node");  in ubifs_sb_verify_signature()
206 		err = -EINVAL;  in ubifs_sb_verify_signature()
210 	snod = list_first_entry(&sleb->nodes, struct ubifs_scan_node, list);  in ubifs_sb_verify_signature()
212 	if (snod->type != UBIFS_SIG_NODE) {  in ubifs_sb_verify_signature()
213 		ubifs_err(c, "Signature node is of wrong type");  in ubifs_sb_verify_signature()
214 		err = -EINVAL;  in ubifs_sb_verify_signature()
218 	signode = snod->node;  in ubifs_sb_verify_signature()
220 	if (le32_to_cpu(signode->len) > snod->len + sizeof(struct ubifs_sig_node)) {  in ubifs_sb_verify_signature()
221 		ubifs_err(c, "invalid signature len %d", le32_to_cpu(signode->len));  in ubifs_sb_verify_signature()
222 		err = -EINVAL;  in ubifs_sb_verify_signature()
226 	if (le32_to_cpu(signode->type) != UBIFS_SIGNATURE_TYPE_PKCS7) {  in ubifs_sb_verify_signature()
227 		ubifs_err(c, "Signature type %d is not supported\n",  in ubifs_sb_verify_signature()
228 			  le32_to_cpu(signode->type));  in ubifs_sb_verify_signature()
229 		err = -EINVAL;  in ubifs_sb_verify_signature()
234 				     signode->sig, le32_to_cpu(signode->len),  in ubifs_sb_verify_signature()
239 		ubifs_err(c, "Failed to verify signature");  in ubifs_sb_verify_signature()
241 		ubifs_msg(c, "Successfully verified super block signature");  in ubifs_sb_verify_signature()
250  * ubifs_init_authentication - initialize UBIFS authentication support
251  * @c: UBIFS file-system description object
253  * This function returns 0 for success or a negative error code otherwise.
255 int ubifs_init_authentication(struct ubifs_info *c)  in ubifs_init_authentication()  argument
262 	if (!c->auth_hash_name) {  in ubifs_init_authentication()
263 		ubifs_err(c, "authentication hash name needed with authentication");  in ubifs_init_authentication()
264 		return -EINVAL;  in ubifs_init_authentication()
267 	c->auth_hash_algo = match_string(hash_algo_name, HASH_ALGO__LAST,  in ubifs_init_authentication()
268 					 c->auth_hash_name);  in ubifs_init_authentication()
269 	if ((int)c->auth_hash_algo < 0) {  in ubifs_init_authentication()
270 		ubifs_err(c, "Unknown hash algo %s specified",  in ubifs_init_authentication()
271 			  c->auth_hash_name);  in ubifs_init_authentication()
272 		return -EINVAL;  in ubifs_init_authentication()
276 		 c->auth_hash_name);  in ubifs_init_authentication()
278 	keyring_key = request_key(&key_type_logon, c->auth_key_name, NULL);  in ubifs_init_authentication()
281 		ubifs_err(c, "Failed to request key: %ld",  in ubifs_init_authentication()
286 	down_read(&keyring_key->sem);  in ubifs_init_authentication()
288 	if (keyring_key->type != &key_type_logon) {  in ubifs_init_authentication()
289 		ubifs_err(c, "key type must be logon");  in ubifs_init_authentication()
290 		err = -ENOKEY;  in ubifs_init_authentication()
297 		err = -EKEYREVOKED;  in ubifs_init_authentication()
301 	c->hash_tfm = crypto_alloc_shash(c->auth_hash_name, 0, 0);  in ubifs_init_authentication()
302 	if (IS_ERR(c->hash_tfm)) {  in ubifs_init_authentication()
303 		err = PTR_ERR(c->hash_tfm);  in ubifs_init_authentication()
304 		ubifs_err(c, "Can not allocate %s: %d",  in ubifs_init_authentication()
305 			  c->auth_hash_name, err);  in ubifs_init_authentication()
309 	c->hash_len = crypto_shash_digestsize(c->hash_tfm);  in ubifs_init_authentication()
310 	if (c->hash_len > UBIFS_HASH_ARR_SZ) {  in ubifs_init_authentication()
311 		ubifs_err(c, "hash %s is bigger than maximum allowed hash size (%d > %d)",  in ubifs_init_authentication()
312 			  c->auth_hash_name, c->hash_len, UBIFS_HASH_ARR_SZ);  in ubifs_init_authentication()
313 		err = -EINVAL;  in ubifs_init_authentication()
317 	c->hmac_tfm = crypto_alloc_shash(hmac_name, 0, 0);  in ubifs_init_authentication()
318 	if (IS_ERR(c->hmac_tfm)) {  in ubifs_init_authentication()
319 		err = PTR_ERR(c->hmac_tfm);  in ubifs_init_authentication()
320 		ubifs_err(c, "Can not allocate %s: %d", hmac_name, err);  in ubifs_init_authentication()
324 	c->hmac_desc_len = crypto_shash_digestsize(c->hmac_tfm);  in ubifs_init_authentication()
325 	if (c->hmac_desc_len > UBIFS_HMAC_ARR_SZ) {  in ubifs_init_authentication()
326 		ubifs_err(c, "hmac %s is bigger than maximum allowed hmac size (%d > %d)",  in ubifs_init_authentication()
327 			  hmac_name, c->hmac_desc_len, UBIFS_HMAC_ARR_SZ);  in ubifs_init_authentication()
328 		err = -EINVAL;  in ubifs_init_authentication()
332 	err = crypto_shash_setkey(c->hmac_tfm, ukp->data, ukp->datalen);  in ubifs_init_authentication()
336 	c->authenticated = true;  in ubifs_init_authentication()
338 	c->log_hash = ubifs_hash_get_desc(c);  in ubifs_init_authentication()
339 	if (IS_ERR(c->log_hash)) {  in ubifs_init_authentication()
340 		err = PTR_ERR(c->log_hash);  in ubifs_init_authentication()
348 		crypto_free_shash(c->hmac_tfm);  in ubifs_init_authentication()
351 		crypto_free_shash(c->hash_tfm);  in ubifs_init_authentication()
353 	up_read(&keyring_key->sem);  in ubifs_init_authentication()
360  * __ubifs_exit_authentication - release resource
361  * @c: UBIFS file-system description object
365 void __ubifs_exit_authentication(struct ubifs_info *c)  in __ubifs_exit_authentication()  argument
367 	if (!ubifs_authenticated(c))  in __ubifs_exit_authentication()
370 	crypto_free_shash(c->hmac_tfm);  in __ubifs_exit_authentication()
371 	crypto_free_shash(c->hash_tfm);  in __ubifs_exit_authentication()
372 	kfree(c->log_hash);  in __ubifs_exit_authentication()
376  * ubifs_node_calc_hmac - calculate the HMAC of a UBIFS node
377  * @c: UBIFS file-system description object
378  * @node: the node to insert a HMAC into.
383  * This function calculates a HMAC of a UBIFS node. The HMAC is expected to be
387 static int ubifs_node_calc_hmac(const struct ubifs_info *c, const void *node,  in ubifs_node_calc_hmac()  argument
390 	SHASH_DESC_ON_STACK(shash, c->hmac_tfm);  in ubifs_node_calc_hmac()
391 	int hmac_len = c->hmac_desc_len;  in ubifs_node_calc_hmac()
394 	ubifs_assert(c, ofs_hmac > 8);  in ubifs_node_calc_hmac()
395 	ubifs_assert(c, ofs_hmac + hmac_len < len);  in ubifs_node_calc_hmac()
397 	shash->tfm = c->hmac_tfm;  in ubifs_node_calc_hmac()
404 	err = crypto_shash_update(shash, node + 8, ofs_hmac - 8);  in ubifs_node_calc_hmac()
409 	if (len - ofs_hmac - hmac_len > 0) {  in ubifs_node_calc_hmac()
411 			    len - ofs_hmac - hmac_len);  in ubifs_node_calc_hmac()
420  * __ubifs_node_insert_hmac - insert a HMAC into a UBIFS node
421  * @c: UBIFS file-system description object
422  * @node: the node to insert a HMAC into.
426  * This function inserts a HMAC at offset @ofs_hmac into the node given in
429  * This function returns 0 for success or a negative error code otherwise.
431 int __ubifs_node_insert_hmac(const struct ubifs_info *c, void *node, int len,  in __ubifs_node_insert_hmac()  argument
434 	return ubifs_node_calc_hmac(c, node, len, ofs_hmac, node + ofs_hmac);  in __ubifs_node_insert_hmac()
438  * __ubifs_node_verify_hmac - verify the HMAC of UBIFS node
439  * @c: UBIFS file-system description object
440  * @node: the node to insert a HMAC into.
445  * @node. Returns 0 if successful or a negative error code otherwise.
447 int __ubifs_node_verify_hmac(const struct ubifs_info *c, const void *node,  in __ubifs_node_verify_hmac()  argument
450 	int hmac_len = c->hmac_desc_len;  in __ubifs_node_verify_hmac()
456 		return -ENOMEM;  in __ubifs_node_verify_hmac()
458 	err = ubifs_node_calc_hmac(c, node, len, ofs_hmac, hmac);  in __ubifs_node_verify_hmac()
471 	return -EPERM;  in __ubifs_node_verify_hmac()
474 int __ubifs_shash_copy_state(const struct ubifs_info *c, struct shash_desc *src,  in __ubifs_shash_copy_state()  argument
480 	state = kmalloc(crypto_shash_descsize(src->tfm), GFP_NOFS);  in __ubifs_shash_copy_state()
482 		return -ENOMEM;  in __ubifs_shash_copy_state()
497  * ubifs_hmac_wkm - Create a HMAC of the well known message
498  * @c: UBIFS file-system description object
501  * This function creates a HMAC of a well known message. This is used
502  * to check if the provided key is suitable to authenticate a UBIFS
503  * image. This is only a convenience to the user to provide a better
506  * This function returns 0 for success or a negative error code otherwise.
508 int ubifs_hmac_wkm(struct ubifs_info *c, u8 *hmac)  in ubifs_hmac_wkm()  argument
512 	if (!ubifs_authenticated(c))  in ubifs_hmac_wkm()
515 	return crypto_shash_tfm_digest(c->hmac_tfm, well_known_message,  in ubifs_hmac_wkm()
516 				       sizeof(well_known_message) - 1, hmac);  in ubifs_hmac_wkm()
520  * ubifs_hmac_zero - test if a HMAC is zero
521  * @c: UBIFS file-system description object
524  * This function tests if a HMAC is zero and returns true if it is
527 bool ubifs_hmac_zero(struct ubifs_info *c, const u8 *hmac)  in ubifs_hmac_zero()  argument
529 	return !memchr_inv(hmac, 0, c->hmac_desc_len);  in ubifs_hmac_zero()