From 306468ce9c4073b85c3d9431da13739a01e6d752 Mon Sep 17 00:00:00 2001 From: bg Date: Thu, 27 Dec 2012 01:21:32 +0100 Subject: [PATCH] [keccak-asm] improving last block handling (reducing stack space) --- keccak/keccak-asm.S | 2 +- keccak/keccak-stub.c | 43 ++++++++++++++++++++----------------------- 2 files changed, 21 insertions(+), 24 deletions(-) diff --git a/keccak/keccak-asm.S b/keccak/keccak-asm.S index 9d613f9..4a13e09 100644 --- a/keccak/keccak-asm.S +++ b/keccak/keccak-asm.S @@ -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] = diff --git a/keccak/keccak-stub.c b/keccak/keccak-stub.c index ff198e7..886e2d1 100644 --- a/keccak/keccak-stub.c +++ b/keccak/keccak-stub.c @@ -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){ -- 2.39.2