ima: support arbitrary hash algorithms in ima_calc_buffer_hash
ima_calc_buffer_hash will be used with different hash algorithms.
This patch provides support for arbitrary hash algorithms in
ima_calc_buffer_hash.
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_api.c b/security/integrity/ima/ima_api.c
index 2cc5dcc..bc1d128 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -18,6 +18,7 @@
#include <linux/fs.h>
#include <linux/xattr.h>
#include <linux/evm.h>
+#include <crypto/hash_info.h>
#include "ima.h"
static const char *IMA_TEMPLATE_NAME = "ima";
@@ -54,6 +55,8 @@
entry->template_len = sizeof(entry->template);
if (!violation) {
+ /* this function uses default algo */
+ hash.hdr.algo = HASH_ALGO_SHA1;
result = ima_calc_buffer_hash(&entry->template,
entry->template_len, &hash.hdr);
if (result < 0) {
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index e5d3ebf..e2be252 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -139,23 +139,39 @@
/*
* Calculate the hash of a given buffer
*/
-int ima_calc_buffer_hash(const void *buf, int len, struct ima_digest_data *hash)
+static int ima_calc_buffer_hash_tfm(const void *buf, int len,
+ struct ima_digest_data *hash,
+ struct crypto_shash *tfm)
{
struct {
struct shash_desc shash;
- char ctx[crypto_shash_descsize(ima_shash_tfm)];
+ char ctx[crypto_shash_descsize(tfm)];
} desc;
- desc.shash.tfm = ima_shash_tfm;
+ desc.shash.tfm = tfm;
desc.shash.flags = 0;
- /* this function uses default algo */
- hash->algo = ima_hash_algo;
- hash->length = crypto_shash_digestsize(ima_shash_tfm);
+ hash->length = crypto_shash_digestsize(tfm);
return crypto_shash_digest(&desc.shash, buf, len, hash->digest);
}
+int ima_calc_buffer_hash(const void *buf, int len, struct ima_digest_data *hash)
+{
+ struct crypto_shash *tfm;
+ int rc;
+
+ tfm = ima_alloc_tfm(hash->algo);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ rc = ima_calc_buffer_hash_tfm(buf, len, hash, tfm);
+
+ ima_free_tfm(tfm);
+
+ return rc;
+}
+
static void __init ima_pcrread(int idx, u8 *pcr)
{
if (!ima_used_chip)