X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=serpent.c;h=6506b2ad2b70495db93c40054bbf997ecf1bf2d3;hb=17332291e15183d71d88ed868275e3cb53917180;hp=8c33bbe59c19d63a7f1568f49632a47930094c8b;hpb=94cad47618f03baf3d750d75c20860c89ac91dbe;p=avr-crypto-lib.git

diff --git a/serpent.c b/serpent.c
index 8c33bbe..6506b2a 100644
--- a/serpent.c
+++ b/serpent.c
@@ -1,6 +1,6 @@
 /* serpent.c */
 /*
-    This file is part of the Crypto-avr-lib/microcrypt-lib.
+    This file is part of the This file is part of the AVR-Crypto-Lib.
     Copyright (C) 2008  Daniel Otte (daniel.otte@rub.de)
 
     This program is free software: you can redistribute it and/or modify
@@ -26,21 +26,12 @@
 #include <stdint.h>
 #include <string.h> /* memset() */
 #include <avr/pgmspace.h>
+#include "memxor.h"
 #include "serpent.h"
 #include "serpent-sboxes.h"
 
 /******************************************************************************/
 
-void memxor(void * dest, void * src, uint8_t size){
-	while(size--){
-		*((uint8_t*)dest) ^= *((uint8_t*)src);
-		dest = (uint8_t*)dest +1;
-		src  = (uint8_t*)src  +1;
-	}
-}
-
-/******************************************************************************/
-
 uint32_t rotl32(uint32_t a, uint8_t n){
 	return ((a<<n) | (a>>(32-n)));
 }
@@ -56,7 +47,7 @@ uint32_t rotr32(uint32_t a, uint8_t n){
 #define X2 (((uint32_t*)b)[2])
 #define X3 (((uint32_t*)b)[3])
 
-static void lt(uint8_t *b){
+static void serpent_lt(uint8_t *b){
 	X0 = rotl32(X0, 13);
 	X2 = rotl32(X2,  3);
 	X1 ^= X0 ^ X2;
@@ -69,7 +60,7 @@ static void lt(uint8_t *b){
 	X2 = rotr32(X2, 10);
 }
 
-static void inv_lt(uint8_t *b){
+static void serpent_inv_lt(uint8_t *b){
 	X2 = rotl32(X2, 10);
 	X0 = rotr32(X0, 5);
 	X2 ^= X3 ^ (X1 << 7);
@@ -84,29 +75,28 @@ static void inv_lt(uint8_t *b){
 
 #define GOLDEN_RATIO 0x9e3779b9l
 
-static uint32_t gen_w(uint32_t * b, uint8_t i){
+static uint32_t serpent_gen_w(uint32_t * b, uint8_t i){
 	uint32_t ret;
 	ret = b[0] ^ b[3] ^ b[5] ^ b[7] ^ GOLDEN_RATIO ^ (uint32_t)i;
 	ret = rotl32(ret, 11);
 	return ret;
 } 
 
-/* key must be 256bit (32 byte) large! */
-void serpent_init(void * key, uint8_t keysize, serpent_ctx_t * ctx){
+void serpent_init(const void* key, uint16_t keysize_b, serpent_ctx_t* ctx){
 	uint32_t buffer[8];
 	uint8_t i,j;
-	if(keysize){
+	if(keysize_b<256){
 		/* keysize is less than 256 bit, padding needed */
 		memset(buffer, 0, 32);
-		memcpy(buffer, key, (keysize+7)/8);
-		((uint8_t*)buffer)[keysize/8] |= 1<<(keysize%8);
+		memcpy(buffer, key, (keysize_b+7)/8);
+		((uint8_t*)buffer)[keysize_b/8] |= 1<<(keysize_b%8);
 	} else {
 		/* keysize is 256 bit */
 		memcpy(buffer, key, 32); 
 	}
 	for(i=0; i<33; ++i){
 		for(j=0; j<4; ++j){
-			ctx->k[i][j] = gen_w(buffer, i*4+j);
+			ctx->k[i][j] = serpent_gen_w(buffer, i*4+j);
 			memmove(buffer, &(buffer[1]), 7*4); /* shift buffer one to the "left" */
 			buffer[7] = ctx->k[i][j];
 		}
@@ -116,32 +106,31 @@ void serpent_init(void * key, uint8_t keysize, serpent_ctx_t * ctx){
 	}
 }
 
-
-void serpent_enc(void* buffer, serpent_ctx_t * ctx){
+void serpent_enc(void* buffer, const serpent_ctx_t* ctx){
 	uint8_t i;
 	for(i=0; i<31; ++i){
-		memxor((uint8_t*)buffer, ctx->k[i], 16);
+		memxor(buffer, ctx->k[i], 16);
 		sbox128(buffer, i);
-		lt((uint8_t*)buffer);
+		serpent_lt((uint8_t*)buffer);
 	}
-	memxor((uint8_t*)buffer, ctx->k[i], 16);
+	memxor(buffer, ctx->k[i], 16);
 	sbox128(buffer, i);
 	++i;
-	memxor((uint8_t*)buffer, ctx->k[i], 16);
+	memxor(buffer, ctx->k[i], 16);
 }
 
-void serpent_dec(void* buffer, serpent_ctx_t * ctx){
+void serpent_dec(void* buffer, const serpent_ctx_t* ctx){
 	int8_t i=32;
 	
-	memxor((uint8_t*)buffer, ctx->k[i], 16);
+	memxor(buffer, ctx->k[i], 16);
 	--i;
 	inv_sbox128(buffer, i);
 	memxor((uint8_t*)buffer, ctx->k[i], 16);
 	--i;
 	for(; i>=0; --i){
-		inv_lt((uint8_t*)buffer);
+		serpent_inv_lt(buffer);
 		inv_sbox128(buffer, i);
-		memxor((uint8_t*)buffer, ctx->k[i], 16);
+		memxor(buffer, ctx->k[i], 16);
 	}
 }
 
@@ -149,4 +138,3 @@ void serpent_dec(void* buffer, serpent_ctx_t * ctx){
 
 
 
-