diff --git a/security/integrity/evm/Kconfig b/security/integrity/evm/Kconfig index d593346d0bba..60221852b26a 100644 --- a/security/integrity/evm/Kconfig +++ b/security/integrity/evm/Kconfig @@ -4,6 +4,7 @@ config EVM select ENCRYPTED_KEYS select CRYPTO_HMAC select CRYPTO_SHA1 + select CRYPTO_HASH_INFO default n help EVM protects a file's security extended attributes against diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h index 1257c3c24723..c3f437f5db10 100644 --- a/security/integrity/evm/evm.h +++ b/security/integrity/evm/evm.h @@ -47,6 +47,11 @@ extern struct crypto_shash *hash_tfm; /* List of EVM protected security xattrs */ extern struct list_head evm_config_xattrnames; +struct evm_digest { + struct ima_digest_data hdr; + char digest[IMA_MAX_DIGEST_SIZE]; +} __packed; + int evm_init_key(void); int evm_update_evmxattr(struct dentry *dentry, const char *req_xattr_name, @@ -54,10 +59,11 @@ int evm_update_evmxattr(struct dentry *dentry, size_t req_xattr_value_len); int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name, const char *req_xattr_value, - size_t req_xattr_value_len, char *digest); + size_t req_xattr_value_len, struct evm_digest *data); int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name, const char *req_xattr_value, - size_t req_xattr_value_len, char type, char *digest); + size_t req_xattr_value_len, char type, + struct evm_digest *data); int evm_init_hmac(struct inode *inode, const struct xattr *xattr, char *hmac_val); int evm_init_secfs(void); diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index c20e3142b541..8a3905bb02c7 100644 --- a/security/integrity/evm/evm_crypto.c +++ b/security/integrity/evm/evm_crypto.c @@ -21,6 +21,7 @@ #include #include #include +#include #include "evm.h" #define EVMKEY "evm-key" @@ -29,7 +30,7 @@ static unsigned char evmkey[MAX_KEY_SIZE]; static int evmkey_len = MAX_KEY_SIZE; struct crypto_shash *hmac_tfm; -struct crypto_shash *hash_tfm; +static struct crypto_shash *evm_tfm[HASH_ALGO__LAST]; static DEFINE_MUTEX(mutex); @@ -38,7 +39,6 @@ static DEFINE_MUTEX(mutex); static unsigned long evm_set_key_flags; static char * const evm_hmac = "hmac(sha1)"; -static char * const evm_hash = "sha1"; /** * evm_set_key() - set EVM HMAC key from the kernel @@ -74,10 +74,10 @@ busy: } EXPORT_SYMBOL_GPL(evm_set_key); -static struct shash_desc *init_desc(char type) +static struct shash_desc *init_desc(char type, uint8_t hash_algo) { long rc; - char *algo; + const char *algo; struct crypto_shash **tfm; struct shash_desc *desc; @@ -89,8 +89,8 @@ static struct shash_desc *init_desc(char type) tfm = &hmac_tfm; algo = evm_hmac; } else { - tfm = &hash_tfm; - algo = evm_hash; + tfm = &evm_tfm[hash_algo]; + algo = hash_algo_name[hash_algo]; } if (*tfm == NULL) { @@ -187,10 +187,10 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode, * each xattr, but attempt to re-use the previously allocated memory. */ static int evm_calc_hmac_or_hash(struct dentry *dentry, - const char *req_xattr_name, - const char *req_xattr_value, - size_t req_xattr_value_len, - char type, char *digest) + const char *req_xattr_name, + const char *req_xattr_value, + size_t req_xattr_value_len, + uint8_t type, struct evm_digest *data) { struct inode *inode = d_backing_inode(dentry); struct xattr_list *xattr; @@ -205,10 +205,12 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry, inode->i_sb->s_user_ns != &init_user_ns) return -EOPNOTSUPP; - desc = init_desc(type); + desc = init_desc(type, data->hdr.algo); if (IS_ERR(desc)) return PTR_ERR(desc); + data->hdr.length = crypto_shash_digestsize(desc->tfm); + error = -ENODATA; list_for_each_entry_rcu(xattr, &evm_config_xattrnames, list) { bool is_ima = false; @@ -240,7 +242,7 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry, if (is_ima) ima_present = true; } - hmac_add_misc(desc, inode, type, digest); + hmac_add_misc(desc, inode, type, data->digest); /* Portable EVM signatures must include an IMA hash */ if (type == EVM_XATTR_PORTABLE_DIGSIG && !ima_present) @@ -253,18 +255,18 @@ out: int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name, const char *req_xattr_value, size_t req_xattr_value_len, - char *digest) + struct evm_digest *data) { return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value, - req_xattr_value_len, EVM_XATTR_HMAC, digest); + req_xattr_value_len, EVM_XATTR_HMAC, data); } int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name, const char *req_xattr_value, size_t req_xattr_value_len, - char type, char *digest) + char type, struct evm_digest *data) { return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value, - req_xattr_value_len, type, digest); + req_xattr_value_len, type, data); } static int evm_is_immutable(struct dentry *dentry, struct inode *inode) @@ -304,7 +306,7 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name, const char *xattr_value, size_t xattr_value_len) { struct inode *inode = d_backing_inode(dentry); - struct evm_ima_xattr_data xattr_data; + struct evm_digest data; int rc = 0; /* @@ -317,13 +319,14 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name, if (rc) return -EPERM; + data.hdr.algo = HASH_ALGO_SHA1; rc = evm_calc_hmac(dentry, xattr_name, xattr_value, - xattr_value_len, xattr_data.digest); + xattr_value_len, &data); if (rc == 0) { - xattr_data.type = EVM_XATTR_HMAC; + data.hdr.xattr.sha1.type = EVM_XATTR_HMAC; rc = __vfs_setxattr_noperm(dentry, XATTR_NAME_EVM, - &xattr_data, - sizeof(xattr_data), 0); + &data.hdr.xattr.data[1], + SHA1_DIGEST_SIZE + 1, 0); } else if (rc == -ENODATA && (inode->i_opflags & IOP_XATTR)) { rc = __vfs_removexattr(dentry, XATTR_NAME_EVM); } @@ -335,7 +338,7 @@ int evm_init_hmac(struct inode *inode, const struct xattr *lsm_xattr, { struct shash_desc *desc; - desc = init_desc(EVM_XATTR_HMAC); + desc = init_desc(EVM_XATTR_HMAC, HASH_ALGO_SHA1); if (IS_ERR(desc)) { pr_info("init_desc failed\n"); return PTR_ERR(desc); diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index f9eff5041e4c..7f3f54d89a6e 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -25,6 +25,7 @@ #include #include +#include #include #include "evm.h" @@ -134,8 +135,9 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, struct integrity_iint_cache *iint) { struct evm_ima_xattr_data *xattr_data = NULL; - struct evm_ima_xattr_data calc; + struct signature_v2_hdr *hdr; enum integrity_status evm_status = INTEGRITY_PASS; + struct evm_digest digest; struct inode *inode; int rc, xattr_len; @@ -171,25 +173,28 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, evm_status = INTEGRITY_FAIL; goto out; } + + digest.hdr.algo = HASH_ALGO_SHA1; rc = evm_calc_hmac(dentry, xattr_name, xattr_value, - xattr_value_len, calc.digest); + xattr_value_len, &digest); if (rc) break; - rc = crypto_memneq(xattr_data->digest, calc.digest, - sizeof(calc.digest)); + rc = crypto_memneq(xattr_data->digest, digest.digest, + SHA1_DIGEST_SIZE); if (rc) rc = -EINVAL; break; case EVM_IMA_XATTR_DIGSIG: case EVM_XATTR_PORTABLE_DIGSIG: + hdr = (struct signature_v2_hdr *)xattr_data; + digest.hdr.algo = hdr->hash_algo; rc = evm_calc_hash(dentry, xattr_name, xattr_value, - xattr_value_len, xattr_data->type, - calc.digest); + xattr_value_len, xattr_data->type, &digest); if (rc) break; rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM, (const char *)xattr_data, xattr_len, - calc.digest, sizeof(calc.digest)); + digest.digest, digest.hdr.length); if (!rc) { inode = d_backing_inode(dentry);