ima: pass full xattr with the signature

For possibility to use xattr type for new signature formats,
pass full xattr to the signature verification function.

Signed-off-by: Dmitry Kasatkin <[e-mail]>
Signed-off-by: Mimi Zohar <[e-mail]>

security/integrity/digsig.c

···
 		}
 	}
 
-	switch (sig[0]) {
+	switch (sig[1]) {
 	case 1:
-		return digsig_verify(keyring[id], sig, siglen,
+		/* v1 API expect signature without xattr type */
+		return digsig_verify(keyring[id], sig + 1, siglen - 1,
 				     digest, digestlen);
 	case 2:
 		return asymmetric_verify(keyring[id], sig, siglen,

security/integrity/evm/evm_main.c

···
 		goto out;
 	}
 
-	xattr_len = rc - 1;
+	xattr_len = rc;
 
 	/* check value type */
 	switch (xattr_data->type) {
···
 		if (rc)
 			break;
 		rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM,
-					xattr_data->digest, xattr_len,
+					(const char *)xattr_data, xattr_len,
 					calc.digest, sizeof(calc.digest));
 		if (!rc) {
 			/* we probably want to replace rsa with hmac here */

security/integrity/ima/ima_appraise.c

···
 	case EVM_IMA_XATTR_DIGSIG:
 		iint->flags |= IMA_DIGSIG;
 		rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
-					     xattr_value->digest, rc - 1,
+					     (const char *)xattr_value, rc,
 					     iint->ima_hash.digest,
 					     iint->ima_hash.length);
 		if (rc == -EOPNOTSUPP) {

security/integrity/integrity.h

···
  * signature format v2 - for using with asymmetric keys
  */
 struct signature_v2_hdr {
+	uint8_t type;		/* xattr type */
 	uint8_t version;	/* signature format version */
 	uint8_t	hash_algo;	/* Digest algorithm [enum pkey_hash_algo] */
 	uint32_t keyid;		/* IMA key identifier - not X509/PGP specific */