Convert hash_hkdf() string inputs to zend_string

Author: narfbg

ext/hash/hash.c

@@ -610,26 +610,25 @@ PHP_FUNCTION(hash_algos)
 RFC5869 HMAC-based key derivation function */
 PHP_FUNCTION(hash_hkdf)
 {
-	zend_string *returnval;
-	char *prk, *ikm, *algo, *info = NULL, *salt = NULL;
-	unsigned char *digest, *K = NULL;
-	int i, rounds;
+	zend_string *returnval, *ikm, *algo, *info = NULL, *salt;
 	zend_long length = 0;
-	size_t ikm_len = 0, algo_len, info_len = 0, salt_len = 0;
+	char *prk, *computed_salt;
+	unsigned char *digest, *K;
+	int i, rounds;
 	const php_hash_ops *ops;
 	void *context;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "ss|lss", &algo, &algo_len, &ikm, &ikm_len, &length, &info, &info_len, &salt, &salt_len) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "SS|lSS", &algo, &ikm, &length, &info, &salt) == FAILURE) {
 		return;
 	}
 
-	ops = php_hash_fetch_ops(algo, algo_len);
+	ops = php_hash_fetch_ops(algo->val, algo->len);
 	if (!ops) {
-		php_error_docref(NULL, E_WARNING, "Unknown hashing algorithm: %s", algo);
+		php_error_docref(NULL, E_WARNING, "Unknown hashing algorithm: %s", algo->val, algo->len);
 		RETURN_FALSE;
 	}
 
-	if (ikm_len <= 0) {
+	if (ikm->len <= 0) {
 		php_error_docref(NULL, E_WARNING, "Input keying material cannot be empty");
 		RETURN_FALSE;
 	}
@@ -646,29 +645,31 @@ PHP_FUNCTION(hash_hkdf)
 		RETURN_FALSE;
 	}
 
-	if (salt_len == 0)
+	if (salt->len == 0)
 	{
-		salt = safe_emalloc(ops->digest_size, ops->digest_size, 0);
+		computed_salt = safe_emalloc(ops->digest_size, ops->digest_size, 0);
 		for (i = 0; i < ops->digest_size; i++)
 		{
-			salt[i] = 0x00;
+			computed_salt[i] = 0x00;
 		}
 	}
+	else {
+		computed_salt = safe_emalloc(salt->len, salt->len, 0);
+		memcpy(computed_salt, salt->val, salt->len);
+	}
 
 	context = emalloc(ops->context_size);
 
 	// Extract
 	ops->hash_init(context);
 	K = emalloc(ops->block_size);
-	php_hash_hmac_prep_key(K, ops, context, salt, salt_len ? salt_len : ops->digest_size);
+	php_hash_hmac_prep_key(K, ops, context, computed_salt, salt->len ? salt->len : ops->digest_size);
 	prk = safe_emalloc(ops->digest_size, ops->digest_size, 0);
-	php_hash_hmac_round(prk, ops, context, K, (unsigned char *) ikm, ikm_len);
+	php_hash_hmac_round(prk, ops, context, K, ikm->val, ikm->len);
 	php_hash_string_xor_char(K, K, 0x6A, ops->block_size);
 	php_hash_hmac_round(prk, ops, context, K, prk, ops->digest_size);
 	ZEND_SECURE_ZERO(K, ops->block_size);
-	if (salt_len == 0) {
-		efree(salt);
-	}
+	efree(computed_salt);
 
 	// Expand
 	returnval = zend_string_alloc(length, 0);
@@ -686,8 +687,8 @@ PHP_FUNCTION(hash_hkdf)
 			ops->hash_update(context, digest, ops->digest_size);
 		}
 
-		if (info_len) {
-			ops->hash_update(context, (unsigned char *) info, info_len);
+		if (info != NULL && info->len > 0) {
+			ops->hash_update(context, info->val, info->len);
 		}
 
 		ops->hash_update(context, c, 1);