diff options
Diffstat (limited to 'security/integrity')
| -rw-r--r-- | security/integrity/ima/ima.h | 8 | ||||
| -rw-r--r-- | security/integrity/ima/ima_api.c | 5 | ||||
| -rw-r--r-- | security/integrity/ima/ima_appraise.c | 2 | ||||
| -rw-r--r-- | security/integrity/ima/ima_main.c | 2 | ||||
| -rw-r--r-- | security/integrity/ima/ima_modsig.c | 48 |
5 files changed, 60 insertions, 5 deletions
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index ed8e19d38805..0bc764c80327 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -207,7 +207,7 @@ int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid, int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func); int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file, void *buf, loff_t size, - enum hash_algo algo); + enum hash_algo algo, struct modsig *modsig); void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct evm_ima_xattr_data *xattr_value, @@ -311,6 +311,7 @@ static inline int ima_read_xattr(struct dentry *dentry, bool ima_hook_supports_modsig(enum ima_hooks func); int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, struct modsig **modsig); +void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size); void ima_free_modsig(struct modsig *modsig); #else static inline bool ima_hook_supports_modsig(enum ima_hooks func) @@ -324,6 +325,11 @@ static inline int ima_read_modsig(enum ima_hooks func, const void *buf, return -EOPNOTSUPP; } +static inline void ima_collect_modsig(struct modsig *modsig, const void *buf, + loff_t size) +{ +} + static inline void ima_free_modsig(struct modsig *modsig) { } diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index f614e22bf39f..ff8b7fb03ea0 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -205,7 +205,7 @@ int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid, */ int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file, void *buf, loff_t size, - enum hash_algo algo) + enum hash_algo algo, struct modsig *modsig) { const char *audit_cause = "failed"; struct inode *inode = file_inode(file); @@ -252,6 +252,9 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, memcpy(iint->ima_hash, &hash, length); iint->version = i_version; + if (modsig) + ima_collect_modsig(modsig, buf, size); + /* Possibly temporary failure due to type of read (eg. O_DIRECT) */ if (!result) iint->flags |= IMA_COLLECTED; diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index d21e40eaba42..136ae4e0ee92 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -435,7 +435,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) !(iint->flags & IMA_HASH)) return; - rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo); + rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo, NULL); if (rc < 0) return; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index d8672e850615..7c8d92cf2755 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -314,7 +314,7 @@ static int process_measurement(struct file *file, const struct cred *cred, hash_algo = ima_get_hash_algo(xattr_value, xattr_len); - rc = ima_collect_measurement(iint, file, buf, size, hash_algo); + rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig); if (rc != 0 && rc != -EBADF && rc != -EINVAL) goto out_locked; diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c index f41ebe370fa0..257387ce3b70 100644 --- a/security/integrity/ima/ima_modsig.c +++ b/security/integrity/ima/ima_modsig.c @@ -17,6 +17,19 @@ struct modsig { struct pkcs7_message *pkcs7_msg; + + enum hash_algo hash_algo; + + /* This digest will go in the 'd-modsig' field of the IMA template. */ + const u8 *digest; + u32 digest_size; + + /* + * This is what will go to the measurement list if the template requires + * storing the signature. + */ + int raw_pkcs7_len; + u8 raw_pkcs7[]; }; /** @@ -71,7 +84,8 @@ int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, sig_len = be32_to_cpu(sig->sig_len); buf_len -= sig_len + sizeof(*sig); - hdr = kmalloc(sizeof(*hdr), GFP_KERNEL); + /* Allocate sig_len additional bytes to hold the raw PKCS#7 data. */ + hdr = kzalloc(sizeof(*hdr) + sig_len, GFP_KERNEL); if (!hdr) return -ENOMEM; @@ -81,11 +95,43 @@ int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, return PTR_ERR(hdr->pkcs7_msg); } + memcpy(hdr->raw_pkcs7, buf + buf_len, sig_len); + hdr->raw_pkcs7_len = sig_len; + + /* We don't know the hash algorithm yet. */ + hdr->hash_algo = HASH_ALGO__LAST; + *modsig = hdr; return 0; } +/** + * ima_collect_modsig - Calculate the file hash without the appended signature. + * + * Since the modsig is part of the file contents, the hash used in its signature + * isn't the same one ordinarily calculated by IMA. Therefore PKCS7 code + * calculates a separate one for signature verification. + */ +void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size) +{ + int rc; + + /* + * Provide the file contents (minus the appended sig) so that the PKCS7 + * code can calculate the file hash. + */ + size -= modsig->raw_pkcs7_len + strlen(MODULE_SIG_STRING) + + sizeof(struct module_signature); + rc = pkcs7_supply_detached_data(modsig->pkcs7_msg, buf, size); + if (rc) + return; + + /* Ask the PKCS7 code to calculate the file hash. */ + rc = pkcs7_get_digest(modsig->pkcs7_msg, &modsig->digest, + &modsig->digest_size, &modsig->hash_algo); +} + int ima_modsig_verify(struct key *keyring, const struct modsig *modsig) { return verify_pkcs7_message_sig(NULL, 0, modsig->pkcs7_msg, keyring, |