@@ -30,12 +30,12 @@
 	OFMD5Hash *hash = [OFMD5Hash MD5Hash];
 	uint8_t *digest;
 	char ret[OF_MD5_DIGEST_SIZE * 2];
 	size_t i;
 
-	[hash updateWithBuffer: string
-			length: length];
+	[hash updateWithBuffer: [self cString]
+			length: [self cStringLength]];
 	digest = [hash digest];
 
 	for (i = 0; i < OF_MD5_DIGEST_SIZE; i++) {
 		uint8_t high, low;
 
@@ -58,12 +58,12 @@
 	OFMD5Hash *hash = [OFSHA1Hash SHA1Hash];
 	uint8_t *digest;
 	char ret[OF_SHA1_DIGEST_SIZE * 2];
 	size_t i;
 
-	[hash updateWithBuffer: string
-			length: length];
+	[hash updateWithBuffer: [self cString]
+			length: [self cStringLength]];
 	digest = [hash digest];
 
 	for (i = 0; i < OF_SHA1_DIGEST_SIZE; i++) {
 		uint8_t high, low;