X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=serpent.c;h=8056eb41d03e1b9623d026e30d2b48db8548e1a7;hb=2159c273c9d3361571a6ff1ab63d9bc76582fbab;hp=b2773fc220bb53cc172972d92592a7cb233f037a;hpb=64eeaf729bb29d0ca05fee5292652e8270335801;p=avr-crypto-lib.git
diff --git a/serpent.c b/serpent.c
index b2773fc..8056eb4 100644
--- a/serpent.c
+++ b/serpent.c
@@ -1,3 +1,21 @@
+/* serpent.c */
+/*
+ This file is part of the Crypto-avr-lib/microcrypt-lib.
+ Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de)
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see .
+*/
/* serpent.c
* a bitsliced implementation of the serpent cipher for avr microcontrollers
* author: Daniel Otte
@@ -8,114 +26,9 @@
#include
#include /* memset() */
#include
+#include "memxor.h"
#include "serpent.h"
-
-uint8_t sbox[] PROGMEM = {
- 0x38, 0xF1, 0xA6, 0x5B, 0xED, 0x42, 0x70, 0x9C,
- 0xFC, 0x27, 0x90, 0x5A, 0x1B, 0xE8, 0x6D, 0x34,
- 0x86, 0x79, 0x3C, 0xAF, 0xD1, 0xE4, 0x0B, 0x52,
- 0x0F, 0xB8, 0xC9, 0x63, 0xD1, 0x24, 0xA7, 0x5E,
- 0x1F, 0x83, 0xC0, 0xB6, 0x25, 0x4A, 0x9E, 0x7D,
- 0xF5, 0x2B, 0x4A, 0x9C, 0x03, 0xE8, 0xD6, 0x71,
- 0x72, 0xC5, 0x84, 0x6B, 0xE9, 0x1F, 0xD3, 0xA0,
- 0x1D, 0xF0, 0xE8, 0x2B, 0x74, 0xCA, 0x93, 0x56,
-/* now the inverted sboxes */
- 0xD3, 0xB0, 0xA6, 0x5C, 0x1E, 0x47, 0xF9, 0x82,
- 0x58, 0x2E, 0xF6, 0xC3, 0xB4, 0x79, 0x1D, 0xA0,
- 0xC9, 0xF4, 0xBE, 0x12, 0x03, 0x6D, 0x58, 0xA7,
- 0x09, 0xA7, 0xBE, 0x6D, 0x35, 0xC2, 0x48, 0xF1,
- 0x50, 0x83, 0xA9, 0x7E, 0x2C, 0xB6, 0x4F, 0xD1,
- 0x8F, 0x29, 0x41, 0xDE, 0xB6, 0x53, 0x7C, 0xA0,
- 0xFA, 0x1D, 0x53, 0x60, 0x49, 0xE7, 0x2C, 0x8B,
- 0x30, 0x6D, 0x9E, 0xF8, 0x5C, 0xB7, 0xA1, 0x42
-};
-
-
-#define SHR_O(a) c=(a)&1; ((a) = (a)>>1)
-#define SHR_I(a) ((a) = (c?0x80:0x00)| ((a)>>1))
-
-static void ip(uint8_t *o, uint32_t *i){
- uint8_t c; // carry
- uint8_t n,m;
- memset(o, 0, 16);
- for(n=0; n<16; ++n){
- for(m=0; m<2; ++m){
- SHR_O(i[0]);
- SHR_I(o[n]);
- SHR_O(i[1]);
- SHR_I(o[n]);
- SHR_O(i[2]);
- SHR_I(o[n]);
- SHR_O(i[3]);
- SHR_I(o[n]);
- }
- }
-}
-
-#undef SHR_I
-#define SHR_I(a) ((a) = (c?0x80000000L:0x00L)| ((a)>>1)) /* we use 32-bit words here */
-
-
-static void fp(uint32_t *o, uint32_t *i){
- uint8_t c; // carry
- uint8_t n,m;
- memset(o, 0, 16);
- for(n=0; n<4; ++n){
- for(m=0; m<8; ++m){
- SHR_O(i[n]);
- SHR_I(o[0]);
- SHR_O(i[n]);
- SHR_I(o[1]);
- SHR_O(i[n]);
- SHR_I(o[2]);
- SHR_O(i[n]);
- SHR_I(o[3]);
- }
- }
-}
-
-/******************************************************************************/
-
-static void sbox128x(uint8_t box, void* w){
- uint8_t sb[16];
- uint8_t i,t,x;
- box &= 0x0f;
- /* load sbox */
- for(i=0; i<8; ++i){
- t = pgm_read_byte(sbox + box*8 + i);
- sb[2*i+0]=t>>4;
- sb[2*i+1]=t&0xf;
- }
- uint8_t o[16];
- ip(o, w);
-
- for(i=0; i<16; ++i){
- t = ((uint8_t*)o)[i];
- x = sb[t>>4];
- x <<= 4;
- x |= sb[t&0xf];
- ((uint8_t*)o)[i] = x;
- }
- fp(w, (uint32_t*)o);
-}
-
-static void sbox128(void * w, uint8_t box){
- sbox128x(box&0x7, w);
-}
-
-static void inv_sbox128(void * w, uint8_t box){
- sbox128x(((box&0x7)|0x8), w);
-}
-
-/******************************************************************************/
-
-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;
- }
-}
+#include "serpent-sboxes.h"
/******************************************************************************/
@@ -170,10 +83,18 @@ static uint32_t gen_w(uint32_t * b, uint8_t i){
}
/* key must be 256bit (32 byte) large! */
-void serpent_genctx(void * key, serpent_ctx_t * ctx){
+void serpent_init(const void* key, uint16_t keysize, serpent_ctx_t* ctx){
uint32_t buffer[8];
uint8_t i,j;
- memcpy(buffer, key, 32);
+ if(keysize<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);
+ } 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);
@@ -187,7 +108,7 @@ void serpent_genctx(void * key, 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);
@@ -200,7 +121,7 @@ void serpent_enc(void* buffer, serpent_ctx_t * ctx){
memxor((uint8_t*)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);