1 files changed, 49 insertions, 17 deletions

diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index 5dd5b140242c..847a2d7dff17 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -26,34 +26,48 @@ 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 shash_desc *init_desc(void)
+static struct shash_desc *init_desc(const char type)
 {
         int rc;
+        char *algo;
+        struct crypto_shash **tfm;
         struct shash_desc *desc;
 
-        if (hmac_tfm == NULL) {
-                hmac_tfm = crypto_alloc_shash(evm_hmac, 0, CRYPTO_ALG_ASYNC);
-                if (IS_ERR(hmac_tfm)) {
+        if (type == EVM_XATTR_HMAC) {
+                tfm = &hmac_tfm;
+                algo = evm_hmac;
+        } else {
+                tfm = &hash_tfm;
+                algo = evm_hash;
+        }
+
+        if (*tfm == NULL) {
+                *tfm = crypto_alloc_shash(algo, 0, CRYPTO_ALG_ASYNC);
+                if (IS_ERR(*tfm)) {
                         pr_err("Can not allocate %s (reason: %ld)\n",
-                               evm_hmac, PTR_ERR(hmac_tfm));
-                        rc = PTR_ERR(hmac_tfm);
-                        hmac_tfm = NULL;
+                               algo, PTR_ERR(*tfm));
+                        rc = PTR_ERR(*tfm);
+                        *tfm = NULL;
                         return ERR_PTR(rc);
                 }
         }
 
-        desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac_tfm),
+        desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(*tfm),
                         GFP_KERNEL);
         if (!desc)
                 return ERR_PTR(-ENOMEM);
 
-        desc->tfm = hmac_tfm;
+        desc->tfm = *tfm;
         desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 
-        rc = crypto_shash_setkey(hmac_tfm, evmkey, evmkey_len);
-        if (rc)
-                goto out;
+        if (type == EVM_XATTR_HMAC) {
+                rc = crypto_shash_setkey(*tfm, evmkey, evmkey_len);
+                if (rc)
+                        goto out;
+        }
+
         rc = crypto_shash_init(desc);
 out:
         if (rc) {
@@ -97,9 +111,11 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
  * the hmac using the requested xattr value. Don't alloc/free memory for
  * each xattr, but attempt to re-use the previously allocated memory.
  */
-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)
+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)
 {
         struct inode *inode = dentry->d_inode;
         struct shash_desc *desc;
@@ -111,7 +127,7 @@ int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
 
         if (!inode->i_op || !inode->i_op->getxattr)
                 return -EOPNOTSUPP;
-        desc = init_desc();
+        desc = init_desc(type);
         if (IS_ERR(desc))
                 return PTR_ERR(desc);
 
@@ -145,6 +161,22 @@ out:
         return error;
 }
 
+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)
+{
+        return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
+                                req_xattr_value_len, EVM_XATTR_HMAC, digest);
+}
+
+int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
+                  const char *req_xattr_value, size_t req_xattr_value_len,
+                  char *digest)
+{
+        return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
+                                req_xattr_value_len, IMA_XATTR_DIGEST, digest);
+}
+
 /*
  * Calculate the hmac and update security.evm xattr
  *
@@ -175,7 +207,7 @@ int evm_init_hmac(struct inode *inode, const struct xattr *lsm_xattr,
 {
         struct shash_desc *desc;
 
-        desc = init_desc();
+        desc = init_desc(EVM_XATTR_HMAC);
         if (IS_ERR(desc)) {
                 printk(KERN_INFO "init_desc failed\n");
                 return PTR_ERR(desc);