/* serpent.c */
/*
- This file is part of the Crypto-avr-lib/microcrypt-lib.
+ 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
#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;
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);
#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(const void* key, uint16_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<256){
+ 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];
}
}
}
-
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, 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);
}
}
-