some cursory review

src/hashes.c

@@ -24,6 +24,10 @@ static const struct hash_info {
 	{ MH_H_BLAKE2S, "blake2s", 32 }
 };
 
+// REVIEW NOTE:
+// This could just be a table where the index into the array is the hash
+// function.  This would make the lookups much simpler.
+
 mh_assert_static(sizeof(hash_infos) / sizeof(hash_infos[0]) == MH_H_COUNT);
 
 // Searches for given hash in hash info table
@@ -40,7 +44,8 @@ static const struct hash_info *find_hash(int hash) {
 
 const char *mh_hash_name(int hash) {
 	const struct hash_info *info = find_hash(hash);
-	return info ? info->name : NULL;
+	return (info != NULL) ? info->name : NULL;
+	// I prefer explicit checks against null pointers
 }
 
 

src/multihash.c

@@ -10,66 +10,69 @@
 #define VARINT_MASK (1 << 7)
 
 static int check_len(size_t len) {
-	if (len < 1) {
+	if (len < 1)
 		return MH_E_TOO_SHORT;
-	} else if (len >= 128) {
+	else if (len >= 128)
 		return MH_E_TOO_LONG;
-	}
 
-	return MH_E_NO_ERROR;
+	return 0;
 }
 
 static int check_multihash(const unsigned char mh[], size_t len) {
-	int error;
+	int err;
 
 	if (len < 3)
 		return MH_E_TOO_SHORT;
 
 	if (mh[0] & VARINT_MASK) {
-		// In near future multihash format will be
-		// extended with varints, this is how we are protecting
-		// against it.
+		// This value is a varint, but there are currently no supported values
+		// that require more than a single byte to represent.
 		return MH_E_VARINT_NOT_SUPPORTED;
 	} else if (mh[1] & VARINT_MASK) {
 		return MH_E_VARINT_NOT_SUPPORTED;
 	}
 
-	error = check_len(mh[1]);
-	if (error)
-		return error;
+	err = check_len(mh[1]);
+	if (err)
+		return err;
 
 
-	return MH_E_NO_ERROR;
+	return 0;
 }
 
 
 // returns hash code or error (which is < 0)
 int mh_multihash_hash(const unsigned char *mh, size_t len) {
-	if (check_multihash(mh, len))
-		return check_multihash(mh, len);
+	int err;
+	err = check_multihash(mh, len);
+		return err;
+
 	return (int) mh[0];
 }
 
 
 // returns length of multihash or error (which is < 0)
 int mh_multihash_length(const unsigned char *mh, size_t len) {
-	if (check_multihash(mh, len))
-		return check_multihash(mh, len);
+	int err;
+	err = check_multihash(mh, len);
+	if (err)
+		return err;
+
 	return (int) mh[1];
 }
 
-// gives access to raw digset inside multihash buffer
+// gives access to raw digest inside multihash buffer
 // returns 0 or negative error
-int mh_multihash_digset(unsigned char *multihash, size_t len, unsigned char **digset,
-		size_t *digset_len) {
+int mh_multihash_digest(unsigned char *multihash, size_t len, unsigned char **digest,
+		size_t *digest_len) {
 	int error = check_multihash(multihash, len);
 	if (error)
 		return error;
 
-	(*digset_len) = (size_t) mh_multihash_length(multihash, len);
-	(*digset) = multihash + 2; // Always true without varint
+	(*digest_len) = (size_t) mh_multihash_length(multihash, len);
+	(*digest) = multihash + 2; // Always true without varint
 
-	return MH_E_NO_ERROR;
+	return 0;
 }
 
 int mh_new_length(int code, size_t hash_len) {
@@ -79,17 +82,17 @@ int mh_new_length(int code, size_t hash_len) {
 	return 2 + hash_len;
 }
 
-int mh_new(unsigned char *buffer, int code, const unsigned char *digset,
-	size_t digset_len) {
+int mh_new(unsigned char *buffer, int code, const unsigned char *digest,
+	size_t digest_len) {
 	if (code & VARINT_MASK)
 		return MH_E_VARINT_NOT_SUPPORTED;
-	if (digset_len > 127)
+	if (digest_len > 127)
 		return MH_E_DIGSET_TOO_LONG;
 
 	buffer[0] = (unsigned char) ((unsigned int) code) & 255;
-	buffer[1] = (unsigned char) digset_len;
-	memcpy(buffer + 2, digset, digset_len);
+	buffer[1] = (unsigned char) digest_len;
+	memcpy(buffer + 2, digest, digest_len);
 
-	return MH_E_NO_ERROR;
+	return 0;
 }