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[keccak-asm] improving last block handling (reducing stack space)

This commit is contained in:
bg 2012-12-27 01:39:06 +01:00
parent 62232d4984
commit 7e757a92ed
1 changed files with 6 additions and 9 deletions
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15
keccak/keccak-stub.c
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@ -93,9 +93,6 @@ void keccak_lastBlock(keccak_ctx_t* ctx, const void* block, uint16_t length_b){
block = (uint8_t*)block + ctx->bs;
length_b -= ctx->r;
}
// uint8_t tmp[ctx->bs];
uint8_t pad[3];
// memset(tmp, 0x00, ctx->bs);
memxor(ctx->a, block, (length_b)/8);
/* appand 1 */
if(length_b & 7){
@ -107,19 +104,19 @@ void keccak_lastBlock(keccak_ctx_t* ctx, const void* block, uint16_t length_b){
}else{
((uint8_t*)ctx->a)[length_b / 8] ^= 0x01;
}
pad[0] = ctx->d;
pad[1] = ctx->bs;
pad[2] = 0x01;
if(length_b / 8 + 1 + 3 <= ctx->bs){
memxor((uint8_t*)ctx->a + length_b / 8 + 1, pad, 3);
*((uint8_t*)ctx->a + length_b / 8 + 1) ^= ctx->d;
*((uint8_t*)ctx->a + length_b / 8 + 2) ^= ctx->bs;
*((uint8_t*)ctx->a + length_b / 8 + 3) ^= 1;
}else{
if(length_b / 8 + 1 + 2 <= ctx->bs){
memxor((uint8_t*)ctx->a + length_b / 8 + 1, pad, 2);
*((uint8_t*)ctx->a + length_b / 8 + 1) ^= ctx->d;
*((uint8_t*)ctx->a + length_b / 8 + 2) ^= ctx->bs;
keccak_f1600(ctx->a);
((uint8_t*)ctx->a)[0] ^= 0x01;
}else{
if(length_b/8+1+1 <= ctx->bs){
memxor((uint8_t*)ctx->a + length_b / 8 + 1, pad, 1);
*((uint8_t*)ctx->a + length_b / 8 + 1) ^= ctx->d;
keccak_f1600(ctx->a);
((uint8_t*)ctx->a)[0] ^= ctx->bs;
((uint8_t*)ctx->a)[1] ^= 0x01;