Commit ff29d0a9 authored by Niels Möller's avatar Niels Möller

Separate rounds and key arguments to _aes_encrypt and _aes_decrypt.

parent 982961a5
2013-05-17 Niels Möller <nisse@lysator.liu.se>
* aes-encrypt-internal.c (_nettle_aes_encrypt): Take rounds and
subkeys as separate arguments, not a struct aes_ctx *. Updated
callers.
* aes-decrypt-internal.c (_nettle_aes_decrypt): Likewise.
* aes-internal.h: Updated prototypes.
* macros.h (ROTL32, ROTL64): Avoid undefined behaviour for zero
rotation count. Unfortunately makes CAST128 a bit slower with
gcc-4.6.3.
......
......@@ -5,7 +5,7 @@
/* nettle, low-level cryptographics library
*
* Copyright (C) 2002 Niels Möller
* Copyright (C) 2002, 2013 Niels Möller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
......@@ -33,7 +33,7 @@
#include "macros.h"
void
_nettle_aes_decrypt(const struct aes_ctx *ctx,
_nettle_aes_decrypt(unsigned rounds, const uint32_t *keys,
const struct aes_table *T,
size_t length, uint8_t *dst,
const uint8_t *src)
......@@ -42,22 +42,22 @@ _nettle_aes_decrypt(const struct aes_ctx *ctx,
{
uint32_t w0, w1, w2, w3; /* working ciphertext */
uint32_t t0, t1, t2, t3;
unsigned round;
unsigned i;
/* Get clear text, using little-endian byte order.
* Also XOR with the first subkey. */
w0 = LE_READ_UINT32(src) ^ ctx->keys[0];
w1 = LE_READ_UINT32(src + 4) ^ ctx->keys[1];
w2 = LE_READ_UINT32(src + 8) ^ ctx->keys[2];
w3 = LE_READ_UINT32(src + 12) ^ ctx->keys[3];
w0 = LE_READ_UINT32(src) ^ keys[0];
w1 = LE_READ_UINT32(src + 4) ^ keys[1];
w2 = LE_READ_UINT32(src + 8) ^ keys[2];
w3 = LE_READ_UINT32(src + 12) ^ keys[3];
for (round = 1; round < ctx->nrounds; round++)
for (i = 1; i < rounds; i++)
{
t0 = AES_ROUND(T, w0, w3, w2, w1, ctx->keys[4*round]);
t1 = AES_ROUND(T, w1, w0, w3, w2, ctx->keys[4*round + 1]);
t2 = AES_ROUND(T, w2, w1, w0, w3, ctx->keys[4*round + 2]);
t3 = AES_ROUND(T, w3, w2, w1, w0, ctx->keys[4*round + 3]);
t0 = AES_ROUND(T, w0, w3, w2, w1, keys[4*i]);
t1 = AES_ROUND(T, w1, w0, w3, w2, keys[4*i + 1]);
t2 = AES_ROUND(T, w2, w1, w0, w3, keys[4*i + 2]);
t3 = AES_ROUND(T, w3, w2, w1, w0, keys[4*i + 3]);
/* We could unroll the loop twice, to avoid these
assignments. If all eight variables fit in registers,
......@@ -70,14 +70,14 @@ _nettle_aes_decrypt(const struct aes_ctx *ctx,
/* Final round */
t0 = AES_FINAL_ROUND(T, w0, w3, w2, w1, ctx->keys[4*round]);
t1 = AES_FINAL_ROUND(T, w1, w0, w3, w2, ctx->keys[4*round + 1]);
t2 = AES_FINAL_ROUND(T, w2, w1, w0, w3, ctx->keys[4*round + 2]);
t3 = AES_FINAL_ROUND(T, w3, w2, w1, w0, ctx->keys[4*round + 3]);
t0 = AES_FINAL_ROUND(T, w0, w3, w2, w1, keys[4*i]);
t1 = AES_FINAL_ROUND(T, w1, w0, w3, w2, keys[4*i + 1]);
t2 = AES_FINAL_ROUND(T, w2, w1, w0, w3, keys[4*i + 2]);
t3 = AES_FINAL_ROUND(T, w3, w2, w1, w0, keys[4*i + 3]);
LE_WRITE_UINT32(dst, t0);
LE_WRITE_UINT32(dst + 8, t2);
LE_WRITE_UINT32(dst + 4, t1);
LE_WRITE_UINT32(dst + 8, t2);
LE_WRITE_UINT32(dst + 12, t3);
}
}
......@@ -5,7 +5,7 @@
/* nettle, low-level cryptographics library
*
* Copyright (C) 2002 Niels Möller
* Copyright (C) 2002, 2013 Niels Möller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
......@@ -342,6 +342,6 @@ aes_decrypt(const struct aes_ctx *ctx,
const uint8_t *src)
{
assert(!(length % AES_BLOCK_SIZE) );
_aes_decrypt(ctx, &_aes_decrypt_table,
_aes_decrypt(ctx->nrounds, ctx->keys, &_aes_decrypt_table,
length, dst, src);
}
......@@ -5,7 +5,7 @@
/* nettle, low-level cryptographics library
*
* Copyright (C) 2002 Niels Möller
* Copyright (C) 2002, 2013 Niels Möller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
......@@ -33,7 +33,7 @@
#include "macros.h"
void
_nettle_aes_encrypt(const struct aes_ctx *ctx,
_nettle_aes_encrypt(unsigned rounds, const uint32_t *keys,
const struct aes_table *T,
size_t length, uint8_t *dst,
const uint8_t *src)
......@@ -42,22 +42,22 @@ _nettle_aes_encrypt(const struct aes_ctx *ctx,
{
uint32_t w0, w1, w2, w3; /* working ciphertext */
uint32_t t0, t1, t2, t3;
unsigned round;
unsigned i;
/* Get clear text, using little-endian byte order.
* Also XOR with the first subkey. */
w0 = LE_READ_UINT32(src) ^ ctx->keys[0];
w1 = LE_READ_UINT32(src + 4) ^ ctx->keys[1];
w2 = LE_READ_UINT32(src + 8) ^ ctx->keys[2];
w3 = LE_READ_UINT32(src + 12) ^ ctx->keys[3];
w0 = LE_READ_UINT32(src) ^ keys[0];
w1 = LE_READ_UINT32(src + 4) ^ keys[1];
w2 = LE_READ_UINT32(src + 8) ^ keys[2];
w3 = LE_READ_UINT32(src + 12) ^ keys[3];
for (round = 1; round < ctx->nrounds; round++)
for (i = 1; i < rounds; i++)
{
t0 = AES_ROUND(T, w0, w1, w2, w3, ctx->keys[4*round]);
t1 = AES_ROUND(T, w1, w2, w3, w0, ctx->keys[4*round + 1]);
t2 = AES_ROUND(T, w2, w3, w0, w1, ctx->keys[4*round + 2]);
t3 = AES_ROUND(T, w3, w0, w1, w2, ctx->keys[4*round + 3]);
t0 = AES_ROUND(T, w0, w1, w2, w3, keys[4*i]);
t1 = AES_ROUND(T, w1, w2, w3, w0, keys[4*i + 1]);
t2 = AES_ROUND(T, w2, w3, w0, w1, keys[4*i + 2]);
t3 = AES_ROUND(T, w3, w0, w1, w2, keys[4*i + 3]);
/* We could unroll the loop twice, to avoid these
assignments. If all eight variables fit in registers,
......@@ -70,14 +70,14 @@ _nettle_aes_encrypt(const struct aes_ctx *ctx,
/* Final round */
t0 = AES_FINAL_ROUND(T, w0, w1, w2, w3, ctx->keys[4*round]);
t1 = AES_FINAL_ROUND(T, w1, w2, w3, w0, ctx->keys[4*round + 1]);
t2 = AES_FINAL_ROUND(T, w2, w3, w0, w1, ctx->keys[4*round + 2]);
t3 = AES_FINAL_ROUND(T, w3, w0, w1, w2, ctx->keys[4*round + 3]);
t0 = AES_FINAL_ROUND(T, w0, w1, w2, w3, keys[4*i]);
t1 = AES_FINAL_ROUND(T, w1, w2, w3, w0, keys[4*i + 1]);
t2 = AES_FINAL_ROUND(T, w2, w3, w0, w1, keys[4*i + 2]);
t3 = AES_FINAL_ROUND(T, w3, w0, w1, w2, keys[4*i + 3]);
LE_WRITE_UINT32(dst, t0);
LE_WRITE_UINT32(dst + 8, t2);
LE_WRITE_UINT32(dst + 4, t1);
LE_WRITE_UINT32(dst + 8, t2);
LE_WRITE_UINT32(dst + 12, t3);
}
}
......
......@@ -5,7 +5,7 @@
/* nettle, low-level cryptographics library
*
* Copyright (C) 2002 Niels Möller
* Copyright (C) 2002, 2013 Niels Möller
*
* The nettle library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
......@@ -40,6 +40,6 @@ aes_encrypt(const struct aes_ctx *ctx,
const uint8_t *src)
{
assert(!(length % AES_BLOCK_SIZE) );
_aes_encrypt(ctx, &_aes_encrypt_table,
_aes_encrypt(ctx->nrounds, ctx->keys, &_aes_encrypt_table,
length, dst, src);
}
......@@ -51,13 +51,13 @@ struct aes_table
};
void
_aes_encrypt(const struct aes_ctx *ctx,
_aes_encrypt(unsigned rounds, const uint32_t *keys,
const struct aes_table *T,
size_t length, uint8_t *dst,
const uint8_t *src);
void
_aes_decrypt(const struct aes_ctx *ctx,
_aes_decrypt(unsigned rounds, const uint32_t *keys,
const struct aes_table *T,
size_t length, uint8_t *dst,
const uint8_t *src);
......
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