/* serpent.h
*
* The serpent block cipher.
*
* For more details on this algorithm, see the Serpent website at
* http://www.cl.cam.ac.uk/~rja14/serpent.html
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 1998, 2000, 2001, Ross Anderson, Eli Biham, Lars
* Knudsen, Rafael R. Sevilla, Niels M�ller
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* I've modified this code a bit so that it interoperates with lsh
* properly. 2000-9-5, Rafael R. Sevilla <dido@pacific.net.ph>
*/
/* NOTE: The copyright notice for the original version of this code
* said "All rights reserved. This code is freely distributed for AES
* selection process. No other use is allowed." However, the authors
* later decided to GPL the code. /nisse */
/* FIXME: Use the READ_UINT32 and WRITE_UINT32 macros, where
* applicable. */
#include "serpent.h"
#include "serpent_sboxes.h"
#include "macros.h"
#include <assert.h>
void
serpent_set_key(struct serpent_ctx *ctx,
unsigned key_size, const uint8_t *key)
{
unsigned i, j;
uint32_t w[132], k[132];
assert(key_size >= SERPENT_MIN_KEY_SIZE);
assert(key_size <= SERPENT_MAX_KEY_SIZE);
for (i = key_size, j = 0;
(i >= 4);
i-=4, j++)
{
assert(j<8);
/* Read the key in the reverse direction. Why? */
w[j] = READ_UINT32(key + i - 4);
}
if (j < 8)
{
/* Pad key, "aabbccddeeff" -> 0xccddeeff, 0x01aabb" */
uint32_t partial = 0x01;
while (i)
partial = (partial << 8 ) | *key++;
w[j++] = partial;
while (j < 8)
w[j++] = 0;
}
for(i=8; i<16; i++)
w[i]=ROL(w[i-8]^w[i-5]^w[i-3]^w[i-1]^PHI^(i-8),11);
for(i=0; i<8; i++)
w[i]=w[i+8];
for(i=8; i<132; i++)
w[i]=ROL(w[i-8]^w[i-5]^w[i-3]^w[i-1]^PHI^i,11);
RND03(w[ 0], w[ 1], w[ 2], w[ 3], k[ 0], k[ 1], k[ 2], k[ 3]);
RND02(w[ 4], w[ 5], w[ 6], w[ 7], k[ 4], k[ 5], k[ 6], k[ 7]);
RND01(w[ 8], w[ 9], w[ 10], w[ 11], k[ 8], k[ 9], k[ 10], k[ 11]);
RND00(w[ 12], w[ 13], w[ 14], w[ 15], k[ 12], k[ 13], k[ 14], k[ 15]);
RND31(w[ 16], w[ 17], w[ 18], w[ 19], k[ 16], k[ 17], k[ 18], k[ 19]);
RND30(w[ 20], w[ 21], w[ 22], w[ 23], k[ 20], k[ 21], k[ 22], k[ 23]);
RND29(w[ 24], w[ 25], w[ 26], w[ 27], k[ 24], k[ 25], k[ 26], k[ 27]);
RND28(w[ 28], w[ 29], w[ 30], w[ 31], k[ 28], k[ 29], k[ 30], k[ 31]);
RND27(w[ 32], w[ 33], w[ 34], w[ 35], k[ 32], k[ 33], k[ 34], k[ 35]);
RND26(w[ 36], w[ 37], w[ 38], w[ 39], k[ 36], k[ 37], k[ 38], k[ 39]);
RND25(w[ 40], w[ 41], w[ 42], w[ 43], k[ 40], k[ 41], k[ 42], k[ 43]);
RND24(w[ 44], w[ 45], w[ 46], w[ 47], k[ 44], k[ 45], k[ 46], k[ 47]);
RND23(w[ 48], w[ 49], w[ 50], w[ 51], k[ 48], k[ 49], k[ 50], k[ 51]);
RND22(w[ 52], w[ 53], w[ 54], w[ 55], k[ 52], k[ 53], k[ 54], k[ 55]);
RND21(w[ 56], w[ 57], w[ 58], w[ 59], k[ 56], k[ 57], k[ 58], k[ 59]);
RND20(w[ 60], w[ 61], w[ 62], w[ 63], k[ 60], k[ 61], k[ 62], k[ 63]);
RND19(w[ 64], w[ 65], w[ 66], w[ 67], k[ 64], k[ 65], k[ 66], k[ 67]);
RND18(w[ 68], w[ 69], w[ 70], w[ 71], k[ 68], k[ 69], k[ 70], k[ 71]);
RND17(w[ 72], w[ 73], w[ 74], w[ 75], k[ 72], k[ 73], k[ 74], k[ 75]);
RND16(w[ 76], w[ 77], w[ 78], w[ 79], k[ 76], k[ 77], k[ 78], k[ 79]);
RND15(w[ 80], w[ 81], w[ 82], w[ 83], k[ 80], k[ 81], k[ 82], k[ 83]);
RND14(w[ 84], w[ 85], w[ 86], w[ 87], k[ 84], k[ 85], k[ 86], k[ 87]);
RND13(w[ 88], w[ 89], w[ 90], w[ 91], k[ 88], k[ 89], k[ 90], k[ 91]);
RND12(w[ 92], w[ 93], w[ 94], w[ 95], k[ 92], k[ 93], k[ 94], k[ 95]);
RND11(w[ 96], w[ 97], w[ 98], w[ 99], k[ 96], k[ 97], k[ 98], k[ 99]);
RND10(w[100], w[101], w[102], w[103], k[100], k[101], k[102], k[103]);
RND09(w[104], w[105], w[106], w[107], k[104], k[105], k[106], k[107]);
RND08(w[108], w[109], w[110], w[111], k[108], k[109], k[110], k[111]);
RND07(w[112], w[113], w[114], w[115], k[112], k[113], k[114], k[115]);
RND06(w[116], w[117], w[118], w[119], k[116], k[117], k[118], k[119]);
RND05(w[120], w[121], w[122], w[123], k[120], k[121], k[122], k[123]);
RND04(w[124], w[125], w[126], w[127], k[124], k[125], k[126], k[127]);
RND03(w[128], w[129], w[130], w[131], k[128], k[129], k[130], k[131]);
for(i=0; i<=32; i++)
for(j=0; j<4; j++)
ctx->keys[i][j] = k[4*i+j];
}
void
serpent_encrypt(struct serpent_ctx *ctx,
unsigned length, uint8_t *dst,
const uint8_t *plain)
{
register uint32_t x0, x1, x2, x3;
register uint32_t y0, y1, y2, y3;
FOR_BLOCKS(length, dst, plain, SERPENT_BLOCK_SIZE)
{
/* Why the reverse order? */
x0=READ_UINT32(plain + 12);
x1=READ_UINT32(plain + 8);
x2=READ_UINT32(plain + 4);
x3=READ_UINT32(plain);
/* Start to encrypt the plaintext x */
keying(x0, x1, x2, x3, ctx->keys[ 0]);
RND00(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[ 1]);
RND01(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[ 2]);
RND02(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[ 3]);
RND03(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[ 4]);
RND04(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[ 5]);
RND05(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[ 6]);
RND06(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[ 7]);
RND07(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[ 8]);
RND08(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[ 9]);
RND09(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[10]);
RND10(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[11]);
RND11(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[12]);
RND12(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[13]);
RND13(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[14]);
RND14(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[15]);
RND15(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[16]);
RND16(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[17]);
RND17(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[18]);
RND18(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[19]);
RND19(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[20]);
RND20(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[21]);
RND21(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[22]);
RND22(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[23]);
RND23(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[24]);
RND24(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[25]);
RND25(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[26]);
RND26(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[27]);
RND27(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[28]);
RND28(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[29]);
RND29(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[30]);
RND30(x0, x1, x2, x3, y0, y1, y2, y3);
transform(y0, y1, y2, y3, x0, x1, x2, x3);
keying(x0, x1, x2, x3, ctx->keys[31]);
RND31(x0, x1, x2, x3, y0, y1, y2, y3);
x0 = y0; x1 = y1; x2 = y2; x3 = y3;
keying(x0, x1, x2, x3, ctx->keys[32]);
/* The ciphertext is now in x */
/* Why the reverse order? */
WRITE_UINT32(dst, x3);
WRITE_UINT32(dst+4, x2);
WRITE_UINT32(dst+8, x1);
WRITE_UINT32(dst+12, x0);
}
}
void
serpent_decrypt(struct serpent_ctx *ctx,
unsigned length, uint8_t *dst,
const uint8_t *cipher)
{
register uint32_t x0, x1, x2, x3;
register uint32_t y0, y1, y2, y3;
FOR_BLOCKS(length, dst, cipher, SERPENT_BLOCK_SIZE)
{
/* Why the reverse order? */
x0 = READ_UINT32(cipher + 12);
x1 = READ_UINT32(cipher + 8);
x2 = READ_UINT32(cipher + 4);
x3 = READ_UINT32(cipher);
/* Start to decrypt the ciphertext x */
keying(x0, x1, x2, x3, ctx->keys[32]);
InvRND31(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[31]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND30(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[30]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND29(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[29]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND28(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[28]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND27(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[27]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND26(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[26]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND25(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[25]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND24(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[24]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND23(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[23]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND22(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[22]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND21(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[21]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND20(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[20]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND19(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[19]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND18(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[18]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND17(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[17]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND16(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[16]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND15(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[15]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND14(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[14]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND13(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[13]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND12(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[12]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND11(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[11]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND10(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[10]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND09(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[ 9]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND08(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[ 8]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND07(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[ 7]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND06(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[ 6]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND05(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[ 5]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND04(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[ 4]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND03(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[ 3]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND02(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[ 2]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND01(x0, x1, x2, x3, y0, y1, y2, y3);
keying(y0, y1, y2, y3, ctx->keys[ 1]);
inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
InvRND00(x0, x1, x2, x3, y0, y1, y2, y3);
x0 = y0; x1 = y1; x2 = y2; x3 = y3;
keying(x0, x1, x2, x3, ctx->keys[ 0]);
/* The plaintext is now in x */
/* Why the reverse order? */
WRITE_UINT32(dst, x3);
WRITE_UINT32(dst+4, x2);
WRITE_UINT32(dst+8, x1);
WRITE_UINT32(dst+12, x0);
}
}