From 1b9e2168d8bff80202dee08a5e0aae878f94814c Mon Sep 17 00:00:00 2001
From: Jakub Sztandera <kubuxu@protonmail.ch>
Date: Sun, 31 Jul 2016 19:31:19 +0100
Subject: [PATCH] create one info table from separate ones

fix mh_hash_default_length
---
 src/hashes.c                 | 73 ++++++++++++++----------------------
 tests/c/test_hashes_length.c |  2 +-
 2 files changed, 30 insertions(+), 45 deletions(-)

diff --git a/src/hashes.c b/src/hashes.c
index a0caf80..c931a67 100644
--- a/src/hashes.c
+++ b/src/hashes.c
@@ -1,65 +1,50 @@
 #include <stdlib.h>
+
 #include "mh/hashes.h"
 
 #include "mh/errors.h"
 #include "mh/assert.h"
 
 
-static const struct hash_name {
+static const struct hash_info {
 	int hash;
 	const char *name;
-} hash_names[] = {
-	{ MH_H_SHA1, "sha1" },
-	{ MH_H_SHA2_256, "sha2-256" },
-	{ MH_H_SHA2_512, "sha2-512" },
-	{ MH_H_SHA3_512, "sha3-512" },
-	{ MH_H_SHA3_384, "sha3-384" },
-	{ MH_H_SHA3_256, "sha3-256" },
-	{ MH_H_SHA3_224, "sha3-224" },
-	{ MH_H_SHAKE_128, "shake-128" },
-	{ MH_H_SHAKE_256, "shake-256" },
-	{ MH_H_BLAKE2B, "blake2b" },
-	{ MH_H_BLAKE2S, "blake2s" }
+	int length;
+} hash_infos[] = {
+	{ MH_H_SHA1, "sha1", 20},
+	{ MH_H_SHA2_256, "sha2-256", 32 },
+	{ MH_H_SHA2_512, "sha2-512", 64 },
+	{ MH_H_SHA3_512, "sha3-512", 64 },
+	{ MH_H_SHA3_384, "sha3-384", 45 },
+	{ MH_H_SHA3_256, "sha3-256", 32 },
+	{ MH_H_SHA3_224, "sha3-224", 28 },
+	{ MH_H_SHAKE_128, "shake-128", 16 },
+	{ MH_H_SHAKE_256, "shake-256", 32 },
+	{ MH_H_BLAKE2B, "blake2b", 64 },
+	{ MH_H_BLAKE2S, "blake2s", 32 }
 };
 
-mh_assert_static(sizeof(hash_names) / sizeof(hash_names[0]) == MH_H_COUNT);
+mh_assert_static(sizeof(hash_infos) / sizeof(hash_infos[0]) == MH_H_COUNT);
 
-const char *mh_hash_name(int hash) {
+// Searches for given hash in hash info table
+static const struct hash_info *find_hash(int hash) {
+	// naive search, could be replaced with binary
 	unsigned int i = 0;
-	for (; i < sizeof(mh_all_hashes) / sizeof(mh_all_hashes[0]); i++) {
-		if (hash_names[i].hash == hash)
-			return hash_names[i].name;
-
+	for (; i < MH_H_COUNT; i++) {
+		if (hash_infos[i].hash == hash)
+			return &hash_infos[i];
 	}
 
 	return NULL;
 }
 
-
-static const int hash_lengths[] = {
-	20, // sha1
-	32, // sha2-256
-	64, // sha2-512
-	64, // sha3-512
-	45, // sha3-364
-	32, // sha3-256
-	28, // sha3-224
-	16, // shake-128
-	32, // shake-256
-	64, // blake2b
-	32, // blake2s
-};
-
-mh_assert_static(sizeof(hash_lengths)/sizeof(hash_lengths[0]) == MH_H_COUNT);
-
-int mh_hash_default_length(int hash) {
-	if (hash < 0 || hash >= MH_H_COUNT)
-		return MH_E_UNKNOWN_CODE;
-
-	return hash_lengths[hash];
+const char *mh_hash_name(int hash) {
+	const struct hash_info *info = find_hash(hash);
+	return info ? info->name : NULL;
 }
 
-int mh_hash_length(const unsigned char multihash[], int len, int *hash_length);
 
-
-int mh_hash_function(const unsigned char multihash[], int len, int *hash);
+int mh_hash_default_length(int hash) {
+	const struct hash_info *info = find_hash(hash);
+	return info ? info->length : MH_E_UNKNOWN_CODE;
+}
diff --git a/tests/c/test_hashes_length.c b/tests/c/test_hashes_length.c
index 7dd8afb..dd02600 100644
--- a/tests/c/test_hashes_length.c
+++ b/tests/c/test_hashes_length.c
@@ -10,7 +10,7 @@ static char *test_all_hashes_have_lengths(void) {
 	int i = 0;
 	int length = 0;
 	for (; i < MH_H_COUNT; i++) {
-		length = mh_hash_default_length(i);
+		length = mh_hash_default_length(mh_all_hashes[i]);
 		sprintf(error_buf, "mh_hash_default_length: hash %d"
 				" returned invalid (%d) default length",
 				i, length);