diff options
Diffstat (limited to 'security/integrity/evm/evm_crypto.c')
| -rw-r--r-- | security/integrity/evm/evm_crypto.c | 94 |
1 files changed, 52 insertions, 42 deletions
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index c9902bd..5dd5b140 100644 --- a/security/integrity/evm/evm_crypto.c +++ b/security/integrity/evm/evm_crypto.c @@ -16,8 +16,8 @@ #include <linux/module.h> #include <linux/crypto.h> #include <linux/xattr.h> -#include <linux/scatterlist.h> #include <keys/encrypted-type.h> +#include <crypto/hash.h> #include "evm.h" #define EVMKEY "evm-key" @@ -25,26 +25,42 @@ static unsigned char evmkey[MAX_KEY_SIZE]; static int evmkey_len = MAX_KEY_SIZE; -static int init_desc(struct hash_desc *desc) +struct crypto_shash *hmac_tfm; + +static struct shash_desc *init_desc(void) { int rc; - - desc->tfm = crypto_alloc_hash(evm_hmac, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(desc->tfm)) { - pr_info("Can not allocate %s (reason: %ld)\n", - evm_hmac, PTR_ERR(desc->tfm)); - rc = PTR_ERR(desc->tfm); - return rc; + struct shash_desc *desc; + + if (hmac_tfm == NULL) { + hmac_tfm = crypto_alloc_shash(evm_hmac, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(hmac_tfm)) { + pr_err("Can not allocate %s (reason: %ld)\n", + evm_hmac, PTR_ERR(hmac_tfm)); + rc = PTR_ERR(hmac_tfm); + hmac_tfm = NULL; + return ERR_PTR(rc); + } } - desc->flags = 0; - rc = crypto_hash_setkey(desc->tfm, evmkey, evmkey_len); + + desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac_tfm), + GFP_KERNEL); + if (!desc) + return ERR_PTR(-ENOMEM); + + desc->tfm = hmac_tfm; + desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + rc = crypto_shash_setkey(hmac_tfm, evmkey, evmkey_len); if (rc) goto out; - rc = crypto_hash_init(desc); + rc = crypto_shash_init(desc); out: - if (rc) - crypto_free_hash(desc->tfm); - return rc; + if (rc) { + kfree(desc); + return ERR_PTR(rc); + } + return desc; } /* Protect against 'cutting & pasting' security.evm xattr, include inode @@ -53,7 +69,7 @@ out: * (Additional directory/file metadata needs to be added for more complete * protection.) */ -static void hmac_add_misc(struct hash_desc *desc, struct inode *inode, +static void hmac_add_misc(struct shash_desc *desc, struct inode *inode, char *digest) { struct h_misc { @@ -63,7 +79,6 @@ static void hmac_add_misc(struct hash_desc *desc, struct inode *inode, gid_t gid; umode_t mode; } hmac_misc; - struct scatterlist sg[1]; memset(&hmac_misc, 0, sizeof hmac_misc); hmac_misc.ino = inode->i_ino; @@ -71,9 +86,8 @@ static void hmac_add_misc(struct hash_desc *desc, struct inode *inode, hmac_misc.uid = inode->i_uid; hmac_misc.gid = inode->i_gid; hmac_misc.mode = inode->i_mode; - sg_init_one(sg, &hmac_misc, sizeof hmac_misc); - crypto_hash_update(desc, sg, sizeof hmac_misc); - crypto_hash_final(desc, digest); + crypto_shash_update(desc, (const u8 *)&hmac_misc, sizeof hmac_misc); + crypto_shash_final(desc, digest); } /* @@ -88,8 +102,7 @@ int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name, char *digest) { struct inode *inode = dentry->d_inode; - struct hash_desc desc; - struct scatterlist sg[1]; + struct shash_desc *desc; char **xattrname; size_t xattr_size = 0; char *xattr_value = NULL; @@ -98,17 +111,17 @@ int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name, if (!inode->i_op || !inode->i_op->getxattr) return -EOPNOTSUPP; - error = init_desc(&desc); - if (error) - return error; + desc = init_desc(); + if (IS_ERR(desc)) + return PTR_ERR(desc); error = -ENODATA; for (xattrname = evm_config_xattrnames; *xattrname != NULL; xattrname++) { if ((req_xattr_name && req_xattr_value) && !strcmp(*xattrname, req_xattr_name)) { error = 0; - sg_init_one(sg, req_xattr_value, req_xattr_value_len); - crypto_hash_update(&desc, sg, req_xattr_value_len); + crypto_shash_update(desc, (const u8 *)req_xattr_value, + req_xattr_value_len); continue; } size = vfs_getxattr_alloc(dentry, *xattrname, @@ -122,13 +135,13 @@ int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name, error = 0; xattr_size = size; - sg_init_one(sg, xattr_value, xattr_size); - crypto_hash_update(&desc, sg, xattr_size); + crypto_shash_update(desc, (const u8 *)xattr_value, xattr_size); } - hmac_add_misc(&desc, inode, digest); - kfree(xattr_value); + hmac_add_misc(desc, inode, digest); + out: - crypto_free_hash(desc.tfm); + kfree(xattr_value); + kfree(desc); return error; } @@ -160,20 +173,17 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name, int evm_init_hmac(struct inode *inode, const struct xattr *lsm_xattr, char *hmac_val) { - struct hash_desc desc; - struct scatterlist sg[1]; - int error; + struct shash_desc *desc; - error = init_desc(&desc); - if (error != 0) { + desc = init_desc(); + if (IS_ERR(desc)) { printk(KERN_INFO "init_desc failed\n"); - return error; + return PTR_ERR(desc); } - sg_init_one(sg, lsm_xattr->value, lsm_xattr->value_len); - crypto_hash_update(&desc, sg, lsm_xattr->value_len); - hmac_add_misc(&desc, inode, hmac_val); - crypto_free_hash(desc.tfm); + crypto_shash_update(desc, lsm_xattr->value, lsm_xattr->value_len); + hmac_add_misc(desc, inode, hmac_val); + kfree(desc); return 0; } |
