ima: differentiate between template hash and file data hash sizes

The TPM v1.2 limits the template hash size to 20 bytes.  This
patch differentiates between the template hash size, as defined
in the ima_template_entry, and the file data hash size, as
defined in the ima_template_data.  Subsequent patches add support
for different file data hash algorithms.

Change log:
- hash digest definition in ima_store_template() should be TPM_DIGEST_SIZE

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>

security/integrity/ima/ima_queue.c

@@ -50,7 +50,7 @@ static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value)
 	key = ima_hash_key(digest_value);
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {
-		rc = memcmp(qe->entry->digest, digest_value, IMA_DIGEST_SIZE);
+		rc = memcmp(qe->entry->digest, digest_value, TPM_DIGEST_SIZE);
 		if (rc == 0) {
 			ret = qe;
 			break;
@@ -106,7 +106,7 @@ static int ima_pcr_extend(const u8 *hash)
 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
 			   const char *op, struct inode *inode)
 {
-	u8 digest[IMA_DIGEST_SIZE];
+	u8 digest[TPM_DIGEST_SIZE];
 	const char *audit_cause = "hash_added";
 	char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX];
 	int audit_info = 1;