ima: provide dedicated hash algo allocation function
This patch provides dedicated hash algo allocation and
deallocation function which can be used by different clients.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 872c669..e5d3ebf 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -39,6 +39,28 @@
return 0;
}
+static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo)
+{
+ struct crypto_shash *tfm = ima_shash_tfm;
+ int rc;
+
+ if (algo != ima_hash_algo && algo < HASH_ALGO__LAST) {
+ tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0);
+ if (IS_ERR(tfm)) {
+ rc = PTR_ERR(tfm);
+ pr_err("Can not allocate %s (reason: %d)\n",
+ hash_algo_name[algo], rc);
+ }
+ }
+ return tfm;
+}
+
+static void ima_free_tfm(struct crypto_shash *tfm)
+{
+ if (tfm != ima_shash_tfm)
+ crypto_free_shash(tfm);
+}
+
/*
* Calculate the MD5/SHA1 file digest
*/
@@ -57,6 +79,8 @@
desc.shash.tfm = tfm;
desc.shash.flags = 0;
+ hash->length = crypto_shash_digestsize(tfm);
+
rc = crypto_shash_init(&desc.shash);
if (rc != 0)
return rc;
@@ -98,25 +122,16 @@
int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
{
- struct crypto_shash *tfm = ima_shash_tfm;
+ struct crypto_shash *tfm;
int rc;
- if (hash->algo != ima_hash_algo && hash->algo < HASH_ALGO__LAST) {
- tfm = crypto_alloc_shash(hash_algo_name[hash->algo], 0, 0);
- if (IS_ERR(tfm)) {
- rc = PTR_ERR(tfm);
- pr_err("Can not allocate %s (reason: %d)\n",
- hash_algo_name[hash->algo], rc);
- return rc;
- }
- }
-
- hash->length = crypto_shash_digestsize(tfm);
+ tfm = ima_alloc_tfm(hash->algo);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
rc = ima_calc_file_hash_tfm(file, hash, tfm);
- if (tfm != ima_shash_tfm)
- crypto_free_shash(tfm);
+ ima_free_tfm(tfm);
return rc;
}