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

This commit is contained in:
bg 2012-12-27 01:21:32 +01:00
parent ddc66bc054
commit 306468ce9c
2 changed files with 21 additions and 24 deletions
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2
keccak/keccak-asm.S
View File

@ -409,7 +409,7 @@ keccak_f1600:
; ret
/*
rho & pi
-- rho & pi --
for(i = 0; i < 5; ++i){
for(j = 0; j < 5; ++j){
b[(2 * i + 3 * j) % 5][j] =

43
keccak/keccak-stub.c
View File

@ -88,53 +88,50 @@ void keccak_nextBlock(keccak_ctx_t* ctx, const void* block){
}
void keccak_lastBlock(keccak_ctx_t* ctx, const void* block, uint16_t length_b){
while(length_b>=ctx->r){
while(length_b >= ctx->r){
keccak_nextBlock(ctx, block);
block = (uint8_t*)block + ctx->bs;
length_b -= ctx->r;
}
uint8_t tmp[ctx->bs];
// uint8_t tmp[ctx->bs];
uint8_t pad[3];
memset(tmp, 0x00, ctx->bs);
memcpy(tmp, block, (length_b+7)/8);
// memset(tmp, 0x00, ctx->bs);
memxor(ctx->a, block, (length_b)/8);
/* appand 1 */
if(length_b & 7){
/* we have some single bits */
uint8_t t;
t = tmp[length_b / 8] >> (8 - (length_b & 7));
t = ((uint8_t*)block)[length_b / 8] >> (8 - (length_b & 7));
t |= 0x01 << (length_b & 7);
tmp[length_b / 8] = t;
((uint8_t*)ctx->a)[length_b / 8] ^= t;
}else{
tmp[length_b / 8] = 0x01;
((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){
memcpy(tmp + length_b / 8 + 1, pad, 3);
memxor((uint8_t*)ctx->a + length_b / 8 + 1, pad, 3);
}else{
if(length_b / 8 + 1 + 2 <= ctx->bs){
memcpy(tmp+length_b/8+1, pad, 2);
keccak_nextBlock(ctx, tmp);
memset(tmp, 0x00, ctx->bs);
tmp[0] = 0x01;
memxor((uint8_t*)ctx->a + length_b / 8 + 1, pad, 2);
keccak_f1600(ctx->a);
((uint8_t*)ctx->a)[0] ^= 0x01;
}else{
if(length_b/8+1+1 <= ctx->bs){
memcpy(tmp + length_b / 8 + 1, pad, 1);
keccak_nextBlock(ctx, tmp);
memset(tmp, 0x00, ctx->bs);
tmp[0] = ctx->bs;
tmp[1] = 0x01;
memxor((uint8_t*)ctx->a + length_b / 8 + 1, pad, 1);
keccak_f1600(ctx->a);
((uint8_t*)ctx->a)[0] ^= ctx->bs;
((uint8_t*)ctx->a)[1] ^= 0x01;
}else{
keccak_nextBlock(ctx, tmp);
memset(tmp, 0x00, ctx->bs);
tmp[0] = ctx->d;
tmp[1] = ctx->bs;
tmp[2] = 0x01;
keccak_f1600(ctx->a);
((uint8_t*)ctx->a)[0] ^= ctx->d;
((uint8_t*)ctx->a)[1] ^= ctx->bs;
((uint8_t*)ctx->a)[2] ^= 0x01;
}
}
}
keccak_nextBlock(ctx, tmp);
keccak_f1600(ctx->a);
}
void keccak_ctx2hash(void* dest, uint16_t length_b, keccak_ctx_t* ctx){