diff options
Diffstat (limited to 'libgcrypt-1.4.6/cipher/serpent.c')
-rw-r--r-- | libgcrypt-1.4.6/cipher/serpent.c | 1956 |
1 files changed, 978 insertions, 978 deletions
diff --git a/libgcrypt-1.4.6/cipher/serpent.c b/libgcrypt-1.4.6/cipher/serpent.c index 0ac0b5b..6b7e655 100644 --- a/libgcrypt-1.4.6/cipher/serpent.c +++ b/libgcrypt-1.4.6/cipher/serpent.c @@ -1,978 +1,978 @@ -/* serpent.c - Implementation of the Serpent encryption algorithm.
- * Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
- *
- * This file is part of Libgcrypt.
- *
- * Libgcrypt is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Lesser general Public License as
- * published by the Free Software Foundation; either version 2.1 of
- * the License, or (at your option) any later version.
- *
- * Libgcrypt 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 Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser 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.
- */
-
-#include <config.h>
-
-#include <string.h>
-#include <stdio.h>
-
-#include "types.h"
-#include "g10lib.h"
-#include "cipher.h"
-#include "bithelp.h"
-
-/* Number of rounds per Serpent encrypt/decrypt operation. */
-#define ROUNDS 32
-
-/* Magic number, used during generating of the subkeys. */
-#define PHI 0x9E3779B9
-
-/* Serpent works on 128 bit blocks. */
-typedef u32 serpent_block_t[4];
-
-/* Serpent key, provided by the user. If the original key is shorter
- than 256 bits, it is padded. */
-typedef u32 serpent_key_t[8];
-
-/* The key schedule consists of 33 128 bit subkeys. */
-typedef u32 serpent_subkeys_t[ROUNDS + 1][4];
-
-/* A Serpent context. */
-typedef struct serpent_context
-{
- serpent_subkeys_t keys; /* Generated subkeys. */
-} serpent_context_t;
-
-
-/* A prototype. */
-static const char *serpent_test (void);
-
-
-#define byte_swap_32(x) \
- (0 \
- | (((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) \
- | (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24))
-
-/* These are the S-Boxes of Serpent. They are copied from Serpents
- reference implementation (the optimized one, contained in
- `floppy2') and are therefore:
-
- Copyright (C) 1998 Ross Anderson, Eli Biham, Lars Knudsen.
-
- To quote the Serpent homepage
- (http://www.cl.cam.ac.uk/~rja14/serpent.html):
-
- "Serpent is now completely in the public domain, and we impose no
- restrictions on its use. This was announced on the 21st August at
- the First AES Candidate Conference. The optimised implementations
- in the submission package are now under the GNU PUBLIC LICENSE
- (GPL), although some comments in the code still say otherwise. You
- are welcome to use Serpent for any application." */
-
-#define SBOX0(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t05, t06, t07, t08, t09; \
- u32 t11, t12, t13, t14, t15, t17, t01; \
- t01 = b ^ c ; \
- t02 = a | d ; \
- t03 = a ^ b ; \
- z = t02 ^ t01; \
- t05 = c | z ; \
- t06 = a ^ d ; \
- t07 = b | c ; \
- t08 = d & t05; \
- t09 = t03 & t07; \
- y = t09 ^ t08; \
- t11 = t09 & y ; \
- t12 = c ^ d ; \
- t13 = t07 ^ t11; \
- t14 = b & t06; \
- t15 = t06 ^ t13; \
- w = ~ t15; \
- t17 = w ^ t14; \
- x = t12 ^ t17; \
- }
-
-#define SBOX0_INVERSE(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t06, t08, t09, t10; \
- u32 t12, t13, t14, t15, t17, t18, t01; \
- t01 = c ^ d ; \
- t02 = a | b ; \
- t03 = b | c ; \
- t04 = c & t01; \
- t05 = t02 ^ t01; \
- t06 = a | t04; \
- y = ~ t05; \
- t08 = b ^ d ; \
- t09 = t03 & t08; \
- t10 = d | y ; \
- x = t09 ^ t06; \
- t12 = a | t05; \
- t13 = x ^ t12; \
- t14 = t03 ^ t10; \
- t15 = a ^ c ; \
- z = t14 ^ t13; \
- t17 = t05 & t13; \
- t18 = t14 | t17; \
- w = t15 ^ t18; \
- }
-
-#define SBOX1(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t06, t07, t08; \
- u32 t10, t11, t12, t13, t16, t17, t01; \
- t01 = a | d ; \
- t02 = c ^ d ; \
- t03 = ~ b ; \
- t04 = a ^ c ; \
- t05 = a | t03; \
- t06 = d & t04; \
- t07 = t01 & t02; \
- t08 = b | t06; \
- y = t02 ^ t05; \
- t10 = t07 ^ t08; \
- t11 = t01 ^ t10; \
- t12 = y ^ t11; \
- t13 = b & d ; \
- z = ~ t10; \
- x = t13 ^ t12; \
- t16 = t10 | x ; \
- t17 = t05 & t16; \
- w = c ^ t17; \
- }
-
-#define SBOX1_INVERSE(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t06, t07, t08; \
- u32 t09, t10, t11, t14, t15, t17, t01; \
- t01 = a ^ b ; \
- t02 = b | d ; \
- t03 = a & c ; \
- t04 = c ^ t02; \
- t05 = a | t04; \
- t06 = t01 & t05; \
- t07 = d | t03; \
- t08 = b ^ t06; \
- t09 = t07 ^ t06; \
- t10 = t04 | t03; \
- t11 = d & t08; \
- y = ~ t09; \
- x = t10 ^ t11; \
- t14 = a | y ; \
- t15 = t06 ^ x ; \
- z = t01 ^ t04; \
- t17 = c ^ t15; \
- w = t14 ^ t17; \
- }
-
-#define SBOX2(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t05, t06, t07, t08; \
- u32 t09, t10, t12, t13, t14, t01; \
- t01 = a | c ; \
- t02 = a ^ b ; \
- t03 = d ^ t01; \
- w = t02 ^ t03; \
- t05 = c ^ w ; \
- t06 = b ^ t05; \
- t07 = b | t05; \
- t08 = t01 & t06; \
- t09 = t03 ^ t07; \
- t10 = t02 | t09; \
- x = t10 ^ t08; \
- t12 = a | d ; \
- t13 = t09 ^ x ; \
- t14 = b ^ t13; \
- z = ~ t09; \
- y = t12 ^ t14; \
- }
-
-#define SBOX2_INVERSE(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t06, t07, t08, t09; \
- u32 t10, t11, t12, t15, t16, t17, t01; \
- t01 = a ^ d ; \
- t02 = c ^ d ; \
- t03 = a & c ; \
- t04 = b | t02; \
- w = t01 ^ t04; \
- t06 = a | c ; \
- t07 = d | w ; \
- t08 = ~ d ; \
- t09 = b & t06; \
- t10 = t08 | t03; \
- t11 = b & t07; \
- t12 = t06 & t02; \
- z = t09 ^ t10; \
- x = t12 ^ t11; \
- t15 = c & z ; \
- t16 = w ^ x ; \
- t17 = t10 ^ t15; \
- y = t16 ^ t17; \
- }
-
-#define SBOX3(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t06, t07, t08; \
- u32 t09, t10, t11, t13, t14, t15, t01; \
- t01 = a ^ c ; \
- t02 = a | d ; \
- t03 = a & d ; \
- t04 = t01 & t02; \
- t05 = b | t03; \
- t06 = a & b ; \
- t07 = d ^ t04; \
- t08 = c | t06; \
- t09 = b ^ t07; \
- t10 = d & t05; \
- t11 = t02 ^ t10; \
- z = t08 ^ t09; \
- t13 = d | z ; \
- t14 = a | t07; \
- t15 = b & t13; \
- y = t08 ^ t11; \
- w = t14 ^ t15; \
- x = t05 ^ t04; \
- }
-
-#define SBOX3_INVERSE(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t06, t07, t09; \
- u32 t11, t12, t13, t14, t16, t01; \
- t01 = c | d ; \
- t02 = a | d ; \
- t03 = c ^ t02; \
- t04 = b ^ t02; \
- t05 = a ^ d ; \
- t06 = t04 & t03; \
- t07 = b & t01; \
- y = t05 ^ t06; \
- t09 = a ^ t03; \
- w = t07 ^ t03; \
- t11 = w | t05; \
- t12 = t09 & t11; \
- t13 = a & y ; \
- t14 = t01 ^ t05; \
- x = b ^ t12; \
- t16 = b | t13; \
- z = t14 ^ t16; \
- }
-
-#define SBOX4(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t06, t08, t09; \
- u32 t10, t11, t12, t13, t14, t15, t16, t01; \
- t01 = a | b ; \
- t02 = b | c ; \
- t03 = a ^ t02; \
- t04 = b ^ d ; \
- t05 = d | t03; \
- t06 = d & t01; \
- z = t03 ^ t06; \
- t08 = z & t04; \
- t09 = t04 & t05; \
- t10 = c ^ t06; \
- t11 = b & c ; \
- t12 = t04 ^ t08; \
- t13 = t11 | t03; \
- t14 = t10 ^ t09; \
- t15 = a & t05; \
- t16 = t11 | t12; \
- y = t13 ^ t08; \
- x = t15 ^ t16; \
- w = ~ t14; \
- }
-
-#define SBOX4_INVERSE(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t06, t07, t09; \
- u32 t10, t11, t12, t13, t15, t01; \
- t01 = b | d ; \
- t02 = c | d ; \
- t03 = a & t01; \
- t04 = b ^ t02; \
- t05 = c ^ d ; \
- t06 = ~ t03; \
- t07 = a & t04; \
- x = t05 ^ t07; \
- t09 = x | t06; \
- t10 = a ^ t07; \
- t11 = t01 ^ t09; \
- t12 = d ^ t04; \
- t13 = c | t10; \
- z = t03 ^ t12; \
- t15 = a ^ t04; \
- y = t11 ^ t13; \
- w = t15 ^ t09; \
- }
-
-#define SBOX5(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t07, t08, t09; \
- u32 t10, t11, t12, t13, t14, t01; \
- t01 = b ^ d ; \
- t02 = b | d ; \
- t03 = a & t01; \
- t04 = c ^ t02; \
- t05 = t03 ^ t04; \
- w = ~ t05; \
- t07 = a ^ t01; \
- t08 = d | w ; \
- t09 = b | t05; \
- t10 = d ^ t08; \
- t11 = b | t07; \
- t12 = t03 | w ; \
- t13 = t07 | t10; \
- t14 = t01 ^ t11; \
- y = t09 ^ t13; \
- x = t07 ^ t08; \
- z = t12 ^ t14; \
- }
-
-#define SBOX5_INVERSE(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t07, t08, t09; \
- u32 t10, t12, t13, t15, t16, t01; \
- t01 = a & d ; \
- t02 = c ^ t01; \
- t03 = a ^ d ; \
- t04 = b & t02; \
- t05 = a & c ; \
- w = t03 ^ t04; \
- t07 = a & w ; \
- t08 = t01 ^ w ; \
- t09 = b | t05; \
- t10 = ~ b ; \
- x = t08 ^ t09; \
- t12 = t10 | t07; \
- t13 = w | x ; \
- z = t02 ^ t12; \
- t15 = t02 ^ t13; \
- t16 = b ^ d ; \
- y = t16 ^ t15; \
- }
-
-#define SBOX6(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t07, t08, t09, t10; \
- u32 t11, t12, t13, t15, t17, t18, t01; \
- t01 = a & d ; \
- t02 = b ^ c ; \
- t03 = a ^ d ; \
- t04 = t01 ^ t02; \
- t05 = b | c ; \
- x = ~ t04; \
- t07 = t03 & t05; \
- t08 = b & x ; \
- t09 = a | c ; \
- t10 = t07 ^ t08; \
- t11 = b | d ; \
- t12 = c ^ t11; \
- t13 = t09 ^ t10; \
- y = ~ t13; \
- t15 = x & t03; \
- z = t12 ^ t07; \
- t17 = a ^ b ; \
- t18 = y ^ t15; \
- w = t17 ^ t18; \
- }
-
-#define SBOX6_INVERSE(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t06, t07, t08, t09; \
- u32 t12, t13, t14, t15, t16, t17, t01; \
- t01 = a ^ c ; \
- t02 = ~ c ; \
- t03 = b & t01; \
- t04 = b | t02; \
- t05 = d | t03; \
- t06 = b ^ d ; \
- t07 = a & t04; \
- t08 = a | t02; \
- t09 = t07 ^ t05; \
- x = t06 ^ t08; \
- w = ~ t09; \
- t12 = b & w ; \
- t13 = t01 & t05; \
- t14 = t01 ^ t12; \
- t15 = t07 ^ t13; \
- t16 = d | t02; \
- t17 = a ^ x ; \
- z = t17 ^ t15; \
- y = t16 ^ t14; \
- }
-
-#define SBOX7(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t05, t06, t08, t09, t10; \
- u32 t11, t13, t14, t15, t16, t17, t01; \
- t01 = a & c ; \
- t02 = ~ d ; \
- t03 = a & t02; \
- t04 = b | t01; \
- t05 = a & b ; \
- t06 = c ^ t04; \
- z = t03 ^ t06; \
- t08 = c | z ; \
- t09 = d | t05; \
- t10 = a ^ t08; \
- t11 = t04 & z ; \
- x = t09 ^ t10; \
- t13 = b ^ x ; \
- t14 = t01 ^ x ; \
- t15 = c ^ t05; \
- t16 = t11 | t13; \
- t17 = t02 | t14; \
- w = t15 ^ t17; \
- y = a ^ t16; \
- }
-
-#define SBOX7_INVERSE(a, b, c, d, w, x, y, z) \
- { \
- u32 t02, t03, t04, t06, t07, t08, t09; \
- u32 t10, t11, t13, t14, t15, t16, t01; \
- t01 = a & b ; \
- t02 = a | b ; \
- t03 = c | t01; \
- t04 = d & t02; \
- z = t03 ^ t04; \
- t06 = b ^ t04; \
- t07 = d ^ z ; \
- t08 = ~ t07; \
- t09 = t06 | t08; \
- t10 = b ^ d ; \
- t11 = a | d ; \
- x = a ^ t09; \
- t13 = c ^ t06; \
- t14 = c & t11; \
- t15 = d | x ; \
- t16 = t01 | t10; \
- w = t13 ^ t15; \
- y = t14 ^ t16; \
- }
-
-/* XOR BLOCK1 into BLOCK0. */
-#define BLOCK_XOR(block0, block1) \
- { \
- block0[0] ^= block1[0]; \
- block0[1] ^= block1[1]; \
- block0[2] ^= block1[2]; \
- block0[3] ^= block1[3]; \
- }
-
-/* Copy BLOCK_SRC to BLOCK_DST. */
-#define BLOCK_COPY(block_dst, block_src) \
- { \
- block_dst[0] = block_src[0]; \
- block_dst[1] = block_src[1]; \
- block_dst[2] = block_src[2]; \
- block_dst[3] = block_src[3]; \
- }
-
-/* Apply SBOX number WHICH to to the block found in ARRAY0 at index
- INDEX, writing the output to the block found in ARRAY1 at index
- INDEX. */
-#define SBOX(which, array0, array1, index) \
- SBOX##which (array0[index + 0], array0[index + 1], \
- array0[index + 2], array0[index + 3], \
- array1[index + 0], array1[index + 1], \
- array1[index + 2], array1[index + 3]);
-
-/* Apply inverse SBOX number WHICH to to the block found in ARRAY0 at
- index INDEX, writing the output to the block found in ARRAY1 at
- index INDEX. */
-#define SBOX_INVERSE(which, array0, array1, index) \
- SBOX##which##_INVERSE (array0[index + 0], array0[index + 1], \
- array0[index + 2], array0[index + 3], \
- array1[index + 0], array1[index + 1], \
- array1[index + 2], array1[index + 3]);
-
-/* Apply the linear transformation to BLOCK. */
-#define LINEAR_TRANSFORMATION(block) \
- { \
- block[0] = rol (block[0], 13); \
- block[2] = rol (block[2], 3); \
- block[1] = block[1] ^ block[0] ^ block[2]; \
- block[3] = block[3] ^ block[2] ^ (block[0] << 3); \
- block[1] = rol (block[1], 1); \
- block[3] = rol (block[3], 7); \
- block[0] = block[0] ^ block[1] ^ block[3]; \
- block[2] = block[2] ^ block[3] ^ (block[1] << 7); \
- block[0] = rol (block[0], 5); \
- block[2] = rol (block[2], 22); \
- }
-
-/* Apply the inverse linear transformation to BLOCK. */
-#define LINEAR_TRANSFORMATION_INVERSE(block) \
- { \
- block[2] = ror (block[2], 22); \
- block[0] = ror (block[0] , 5); \
- block[2] = block[2] ^ block[3] ^ (block[1] << 7); \
- block[0] = block[0] ^ block[1] ^ block[3]; \
- block[3] = ror (block[3], 7); \
- block[1] = ror (block[1], 1); \
- block[3] = block[3] ^ block[2] ^ (block[0] << 3); \
- block[1] = block[1] ^ block[0] ^ block[2]; \
- block[2] = ror (block[2], 3); \
- block[0] = ror (block[0], 13); \
- }
-
-/* Apply a Serpent round to BLOCK, using the SBOX number WHICH and the
- subkeys contained in SUBKEYS. Use BLOCK_TMP as temporary storage.
- This macro increments `round'. */
-#define ROUND(which, subkeys, block, block_tmp) \
- { \
- BLOCK_XOR (block, subkeys[round]); \
- round++; \
- SBOX (which, block, block_tmp, 0); \
- LINEAR_TRANSFORMATION (block_tmp); \
- BLOCK_COPY (block, block_tmp); \
- }
-
-/* Apply the last Serpent round to BLOCK, using the SBOX number WHICH
- and the subkeys contained in SUBKEYS. Use BLOCK_TMP as temporary
- storage. The result will be stored in BLOCK_TMP. This macro
- increments `round'. */
-#define ROUND_LAST(which, subkeys, block, block_tmp) \
- { \
- BLOCK_XOR (block, subkeys[round]); \
- round++; \
- SBOX (which, block, block_tmp, 0); \
- BLOCK_XOR (block_tmp, subkeys[round]); \
- round++; \
- }
-
-/* Apply an inverse Serpent round to BLOCK, using the SBOX number
- WHICH and the subkeys contained in SUBKEYS. Use BLOCK_TMP as
- temporary storage. This macro increments `round'. */
-#define ROUND_INVERSE(which, subkey, block, block_tmp) \
- { \
- LINEAR_TRANSFORMATION_INVERSE (block); \
- SBOX_INVERSE (which, block, block_tmp, 0); \
- BLOCK_XOR (block_tmp, subkey[round]); \
- round--; \
- BLOCK_COPY (block, block_tmp); \
- }
-
-/* Apply the first Serpent round to BLOCK, using the SBOX number WHICH
- and the subkeys contained in SUBKEYS. Use BLOCK_TMP as temporary
- storage. The result will be stored in BLOCK_TMP. This macro
- increments `round'. */
-#define ROUND_FIRST_INVERSE(which, subkeys, block, block_tmp) \
- { \
- BLOCK_XOR (block, subkeys[round]); \
- round--; \
- SBOX_INVERSE (which, block, block_tmp, 0); \
- BLOCK_XOR (block_tmp, subkeys[round]); \
- round--; \
- }
-
-/* Convert the user provided key KEY of KEY_LENGTH bytes into the
- internally used format. */
-static void
-serpent_key_prepare (const byte *key, unsigned int key_length,
- serpent_key_t key_prepared)
-{
- int i;
-
- /* Copy key. */
- for (i = 0; i < key_length / 4; i++)
- {
-#ifdef WORDS_BIGENDIAN
- key_prepared[i] = byte_swap_32 (((u32 *) key)[i]);
-#else
- key_prepared[i] = ((u32 *) key)[i];
-#endif
- }
-
- if (i < 8)
- {
- /* Key must be padded according to the Serpent
- specification. */
- key_prepared[i] = 0x00000001;
-
- for (i++; i < 8; i++)
- key_prepared[i] = 0;
- }
-}
-
-/* Derive the 33 subkeys from KEY and store them in SUBKEYS. */
-static void
-serpent_subkeys_generate (serpent_key_t key, serpent_subkeys_t subkeys)
-{
- u32 w_real[140]; /* The `prekey'. */
- u32 k[132];
- u32 *w = &w_real[8];
- int i, j;
-
- /* Initialize with key values. */
- for (i = 0; i < 8; i++)
- w[i - 8] = key[i];
-
- /* Expand to intermediate key using the affine recurrence. */
- for (i = 0; i < 132; i++)
- w[i] = rol (w[i - 8] ^ w[i - 5] ^ w[i - 3] ^ w[i - 1] ^ PHI ^ i, 11);
-
- /* Calculate subkeys via S-Boxes, in bitslice mode. */
- SBOX (3, w, k, 0);
- SBOX (2, w, k, 4);
- SBOX (1, w, k, 8);
- SBOX (0, w, k, 12);
- SBOX (7, w, k, 16);
- SBOX (6, w, k, 20);
- SBOX (5, w, k, 24);
- SBOX (4, w, k, 28);
- SBOX (3, w, k, 32);
- SBOX (2, w, k, 36);
- SBOX (1, w, k, 40);
- SBOX (0, w, k, 44);
- SBOX (7, w, k, 48);
- SBOX (6, w, k, 52);
- SBOX (5, w, k, 56);
- SBOX (4, w, k, 60);
- SBOX (3, w, k, 64);
- SBOX (2, w, k, 68);
- SBOX (1, w, k, 72);
- SBOX (0, w, k, 76);
- SBOX (7, w, k, 80);
- SBOX (6, w, k, 84);
- SBOX (5, w, k, 88);
- SBOX (4, w, k, 92);
- SBOX (3, w, k, 96);
- SBOX (2, w, k, 100);
- SBOX (1, w, k, 104);
- SBOX (0, w, k, 108);
- SBOX (7, w, k, 112);
- SBOX (6, w, k, 116);
- SBOX (5, w, k, 120);
- SBOX (4, w, k, 124);
- SBOX (3, w, k, 128);
-
- /* Renumber subkeys. */
- for (i = 0; i < ROUNDS + 1; i++)
- for (j = 0; j < 4; j++)
- subkeys[i][j] = k[4 * i + j];
-}
-
-/* Initialize CONTEXT with the key KEY of KEY_LENGTH bits. */
-static void
-serpent_setkey_internal (serpent_context_t *context,
- const byte *key, unsigned int key_length)
-{
- serpent_key_t key_prepared;
-
- serpent_key_prepare (key, key_length, key_prepared);
- serpent_subkeys_generate (key_prepared, context->keys);
- _gcry_burn_stack (272 * sizeof (u32));
-}
-
-/* Initialize CTX with the key KEY of KEY_LENGTH bytes. */
-static gcry_err_code_t
-serpent_setkey (void *ctx,
- const byte *key, unsigned int key_length)
-{
- serpent_context_t *context = ctx;
- static const char *serpent_test_ret;
- static int serpent_init_done;
- gcry_err_code_t ret = GPG_ERR_NO_ERROR;
-
- if (! serpent_init_done)
- {
- /* Execute a self-test the first time, Serpent is used. */
- serpent_test_ret = serpent_test ();
- if (serpent_test_ret)
- log_error ("Serpent test failure: %s\n", serpent_test_ret);
- serpent_init_done = 1;
- }
-
- if (serpent_test_ret)
- ret = GPG_ERR_SELFTEST_FAILED;
- else
- {
- serpent_setkey_internal (context, key, key_length);
- _gcry_burn_stack (sizeof (serpent_key_t));
- }
-
- return ret;
-}
-
-static void
-serpent_encrypt_internal (serpent_context_t *context,
- const serpent_block_t input, serpent_block_t output)
-{
- serpent_block_t b, b_next;
- int round = 0;
-
-#ifdef WORDS_BIGENDIAN
- b[0] = byte_swap_32 (input[0]);
- b[1] = byte_swap_32 (input[1]);
- b[2] = byte_swap_32 (input[2]);
- b[3] = byte_swap_32 (input[3]);
-#else
- b[0] = input[0];
- b[1] = input[1];
- b[2] = input[2];
- b[3] = input[3];
-#endif
-
- ROUND (0, context->keys, b, b_next);
- ROUND (1, context->keys, b, b_next);
- ROUND (2, context->keys, b, b_next);
- ROUND (3, context->keys, b, b_next);
- ROUND (4, context->keys, b, b_next);
- ROUND (5, context->keys, b, b_next);
- ROUND (6, context->keys, b, b_next);
- ROUND (7, context->keys, b, b_next);
- ROUND (0, context->keys, b, b_next);
- ROUND (1, context->keys, b, b_next);
- ROUND (2, context->keys, b, b_next);
- ROUND (3, context->keys, b, b_next);
- ROUND (4, context->keys, b, b_next);
- ROUND (5, context->keys, b, b_next);
- ROUND (6, context->keys, b, b_next);
- ROUND (7, context->keys, b, b_next);
- ROUND (0, context->keys, b, b_next);
- ROUND (1, context->keys, b, b_next);
- ROUND (2, context->keys, b, b_next);
- ROUND (3, context->keys, b, b_next);
- ROUND (4, context->keys, b, b_next);
- ROUND (5, context->keys, b, b_next);
- ROUND (6, context->keys, b, b_next);
- ROUND (7, context->keys, b, b_next);
- ROUND (0, context->keys, b, b_next);
- ROUND (1, context->keys, b, b_next);
- ROUND (2, context->keys, b, b_next);
- ROUND (3, context->keys, b, b_next);
- ROUND (4, context->keys, b, b_next);
- ROUND (5, context->keys, b, b_next);
- ROUND (6, context->keys, b, b_next);
-
- ROUND_LAST (7, context->keys, b, b_next);
-
-#ifdef WORDS_BIGENDIAN
- output[0] = byte_swap_32 (b_next[0]);
- output[1] = byte_swap_32 (b_next[1]);
- output[2] = byte_swap_32 (b_next[2]);
- output[3] = byte_swap_32 (b_next[3]);
-#else
- output[0] = b_next[0];
- output[1] = b_next[1];
- output[2] = b_next[2];
- output[3] = b_next[3];
-#endif
-}
-
-static void
-serpent_decrypt_internal (serpent_context_t *context,
- const serpent_block_t input, serpent_block_t output)
-{
- serpent_block_t b, b_next;
- int round = ROUNDS;
-
-#ifdef WORDS_BIGENDIAN
- b_next[0] = byte_swap_32 (input[0]);
- b_next[1] = byte_swap_32 (input[1]);
- b_next[2] = byte_swap_32 (input[2]);
- b_next[3] = byte_swap_32 (input[3]);
-#else
- b_next[0] = input[0];
- b_next[1] = input[1];
- b_next[2] = input[2];
- b_next[3] = input[3];
-#endif
-
- ROUND_FIRST_INVERSE (7, context->keys, b_next, b);
-
- ROUND_INVERSE (6, context->keys, b, b_next);
- ROUND_INVERSE (5, context->keys, b, b_next);
- ROUND_INVERSE (4, context->keys, b, b_next);
- ROUND_INVERSE (3, context->keys, b, b_next);
- ROUND_INVERSE (2, context->keys, b, b_next);
- ROUND_INVERSE (1, context->keys, b, b_next);
- ROUND_INVERSE (0, context->keys, b, b_next);
- ROUND_INVERSE (7, context->keys, b, b_next);
- ROUND_INVERSE (6, context->keys, b, b_next);
- ROUND_INVERSE (5, context->keys, b, b_next);
- ROUND_INVERSE (4, context->keys, b, b_next);
- ROUND_INVERSE (3, context->keys, b, b_next);
- ROUND_INVERSE (2, context->keys, b, b_next);
- ROUND_INVERSE (1, context->keys, b, b_next);
- ROUND_INVERSE (0, context->keys, b, b_next);
- ROUND_INVERSE (7, context->keys, b, b_next);
- ROUND_INVERSE (6, context->keys, b, b_next);
- ROUND_INVERSE (5, context->keys, b, b_next);
- ROUND_INVERSE (4, context->keys, b, b_next);
- ROUND_INVERSE (3, context->keys, b, b_next);
- ROUND_INVERSE (2, context->keys, b, b_next);
- ROUND_INVERSE (1, context->keys, b, b_next);
- ROUND_INVERSE (0, context->keys, b, b_next);
- ROUND_INVERSE (7, context->keys, b, b_next);
- ROUND_INVERSE (6, context->keys, b, b_next);
- ROUND_INVERSE (5, context->keys, b, b_next);
- ROUND_INVERSE (4, context->keys, b, b_next);
- ROUND_INVERSE (3, context->keys, b, b_next);
- ROUND_INVERSE (2, context->keys, b, b_next);
- ROUND_INVERSE (1, context->keys, b, b_next);
- ROUND_INVERSE (0, context->keys, b, b_next);
-
-
-#ifdef WORDS_BIGENDIAN
- output[0] = byte_swap_32 (b_next[0]);
- output[1] = byte_swap_32 (b_next[1]);
- output[2] = byte_swap_32 (b_next[2]);
- output[3] = byte_swap_32 (b_next[3]);
-#else
- output[0] = b_next[0];
- output[1] = b_next[1];
- output[2] = b_next[2];
- output[3] = b_next[3];
-#endif
-}
-
-static void
-serpent_encrypt (void *ctx, byte *buffer_out, const byte *buffer_in)
-{
- serpent_context_t *context = ctx;
-
- serpent_encrypt_internal (context,
- (const u32 *) buffer_in, (u32 *) buffer_out);
- _gcry_burn_stack (2 * sizeof (serpent_block_t));
-}
-
-static void
-serpent_decrypt (void *ctx, byte *buffer_out, const byte *buffer_in)
-{
- serpent_context_t *context = ctx;
-
- serpent_decrypt_internal (context,
- (const u32 *) buffer_in,
- (u32 *) buffer_out);
- _gcry_burn_stack (2 * sizeof (serpent_block_t));
-}
-
-
-
-/* Serpent test. */
-
-static const char *
-serpent_test (void)
-{
- serpent_context_t context;
- unsigned char scratch[16];
- unsigned int i;
-
- static struct test
- {
- int key_length;
- unsigned char key[32];
- unsigned char text_plain[16];
- unsigned char text_cipher[16];
- } test_data[] =
- {
- {
- 16,
- "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
- "\xD2\x9D\x57\x6F\xCE\xA3\xA3\xA7\xED\x90\x99\xF2\x92\x73\xD7\x8E",
- "\xB2\x28\x8B\x96\x8A\xE8\xB0\x86\x48\xD1\xCE\x96\x06\xFD\x99\x2D"
- },
- {
- 24,
- "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
- "\x00\x00\x00\x00\x00\x00\x00\x00",
- "\xD2\x9D\x57\x6F\xCE\xAB\xA3\xA7\xED\x98\x99\xF2\x92\x7B\xD7\x8E",
- "\x13\x0E\x35\x3E\x10\x37\xC2\x24\x05\xE8\xFA\xEF\xB2\xC3\xC3\xE9"
- },
- {
- 32,
- "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
- "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
- "\xD0\x95\x57\x6F\xCE\xA3\xE3\xA7\xED\x98\xD9\xF2\x90\x73\xD7\x8E",
- "\xB9\x0E\xE5\x86\x2D\xE6\x91\x68\xF2\xBD\xD5\x12\x5B\x45\x47\x2B"
- },
- {
- 32,
- "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
- "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
- "\x00\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00\x03\x00\x00\x00",
- "\x20\x61\xA4\x27\x82\xBD\x52\xEC\x69\x1E\xC3\x83\xB0\x3B\xA7\x7C"
- },
- {
- 0
- },
- };
-
- for (i = 0; test_data[i].key_length; i++)
- {
- serpent_setkey_internal (&context, test_data[i].key,
- test_data[i].key_length);
- serpent_encrypt_internal (&context,
- (const u32 *) test_data[i].text_plain,
- (u32 *) scratch);
-
- if (memcmp (scratch, test_data[i].text_cipher, sizeof (serpent_block_t)))
- switch (test_data[i].key_length)
- {
- case 16:
- return "Serpent-128 test encryption failed.";
- case 24:
- return "Serpent-192 test encryption failed.";
- case 32:
- return "Serpent-256 test encryption failed.";
- }
-
- serpent_decrypt_internal (&context,
- (const u32 *) test_data[i].text_cipher,
- (u32 *) scratch);
- if (memcmp (scratch, test_data[i].text_plain, sizeof (serpent_block_t)))
- switch (test_data[i].key_length)
- {
- case 16:
- return "Serpent-128 test decryption failed.";
- case 24:
- return "Serpent-192 test decryption failed.";
- case 32:
- return "Serpent-256 test decryption failed.";
- }
- }
-
- return NULL;
-}
-
-
-
-/* "SERPENT" is an alias for "SERPENT128". */
-static const char *cipher_spec_serpent128_aliases[] =
- {
- "SERPENT",
- NULL
- };
-
-gcry_cipher_spec_t _gcry_cipher_spec_serpent128 =
- {
- "SERPENT128", cipher_spec_serpent128_aliases, NULL, 16, 128,
- sizeof (serpent_context_t),
- serpent_setkey, serpent_encrypt, serpent_decrypt
- };
-
-gcry_cipher_spec_t _gcry_cipher_spec_serpent192 =
- {
- "SERPENT192", NULL, NULL, 16, 192,
- sizeof (serpent_context_t),
- serpent_setkey, serpent_encrypt, serpent_decrypt
- };
-
-gcry_cipher_spec_t _gcry_cipher_spec_serpent256 =
- {
- "SERPENT256", NULL, NULL, 16, 256,
- sizeof (serpent_context_t),
- serpent_setkey, serpent_encrypt, serpent_decrypt
- };
+/* serpent.c - Implementation of the Serpent encryption algorithm. + * Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc. + * + * This file is part of Libgcrypt. + * + * Libgcrypt is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser general Public License as + * published by the Free Software Foundation; either version 2.1 of + * the License, or (at your option) any later version. + * + * Libgcrypt 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 Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser 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. + */ + +#include <config.h> + +#include <string.h> +#include <stdio.h> + +#include "types.h" +#include "g10lib.h" +#include "cipher.h" +#include "bithelp.h" + +/* Number of rounds per Serpent encrypt/decrypt operation. */ +#define ROUNDS 32 + +/* Magic number, used during generating of the subkeys. */ +#define PHI 0x9E3779B9 + +/* Serpent works on 128 bit blocks. */ +typedef u32 serpent_block_t[4]; + +/* Serpent key, provided by the user. If the original key is shorter + than 256 bits, it is padded. */ +typedef u32 serpent_key_t[8]; + +/* The key schedule consists of 33 128 bit subkeys. */ +typedef u32 serpent_subkeys_t[ROUNDS + 1][4]; + +/* A Serpent context. */ +typedef struct serpent_context +{ + serpent_subkeys_t keys; /* Generated subkeys. */ +} serpent_context_t; + + +/* A prototype. */ +static const char *serpent_test (void); + + +#define byte_swap_32(x) \ + (0 \ + | (((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) \ + | (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24)) + +/* These are the S-Boxes of Serpent. They are copied from Serpents + reference implementation (the optimized one, contained in + `floppy2') and are therefore: + + Copyright (C) 1998 Ross Anderson, Eli Biham, Lars Knudsen. + + To quote the Serpent homepage + (http://www.cl.cam.ac.uk/~rja14/serpent.html): + + "Serpent is now completely in the public domain, and we impose no + restrictions on its use. This was announced on the 21st August at + the First AES Candidate Conference. The optimised implementations + in the submission package are now under the GNU PUBLIC LICENSE + (GPL), although some comments in the code still say otherwise. You + are welcome to use Serpent for any application." */ + +#define SBOX0(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t05, t06, t07, t08, t09; \ + u32 t11, t12, t13, t14, t15, t17, t01; \ + t01 = b ^ c ; \ + t02 = a | d ; \ + t03 = a ^ b ; \ + z = t02 ^ t01; \ + t05 = c | z ; \ + t06 = a ^ d ; \ + t07 = b | c ; \ + t08 = d & t05; \ + t09 = t03 & t07; \ + y = t09 ^ t08; \ + t11 = t09 & y ; \ + t12 = c ^ d ; \ + t13 = t07 ^ t11; \ + t14 = b & t06; \ + t15 = t06 ^ t13; \ + w = ~ t15; \ + t17 = w ^ t14; \ + x = t12 ^ t17; \ + } + +#define SBOX0_INVERSE(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t06, t08, t09, t10; \ + u32 t12, t13, t14, t15, t17, t18, t01; \ + t01 = c ^ d ; \ + t02 = a | b ; \ + t03 = b | c ; \ + t04 = c & t01; \ + t05 = t02 ^ t01; \ + t06 = a | t04; \ + y = ~ t05; \ + t08 = b ^ d ; \ + t09 = t03 & t08; \ + t10 = d | y ; \ + x = t09 ^ t06; \ + t12 = a | t05; \ + t13 = x ^ t12; \ + t14 = t03 ^ t10; \ + t15 = a ^ c ; \ + z = t14 ^ t13; \ + t17 = t05 & t13; \ + t18 = t14 | t17; \ + w = t15 ^ t18; \ + } + +#define SBOX1(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t06, t07, t08; \ + u32 t10, t11, t12, t13, t16, t17, t01; \ + t01 = a | d ; \ + t02 = c ^ d ; \ + t03 = ~ b ; \ + t04 = a ^ c ; \ + t05 = a | t03; \ + t06 = d & t04; \ + t07 = t01 & t02; \ + t08 = b | t06; \ + y = t02 ^ t05; \ + t10 = t07 ^ t08; \ + t11 = t01 ^ t10; \ + t12 = y ^ t11; \ + t13 = b & d ; \ + z = ~ t10; \ + x = t13 ^ t12; \ + t16 = t10 | x ; \ + t17 = t05 & t16; \ + w = c ^ t17; \ + } + +#define SBOX1_INVERSE(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t06, t07, t08; \ + u32 t09, t10, t11, t14, t15, t17, t01; \ + t01 = a ^ b ; \ + t02 = b | d ; \ + t03 = a & c ; \ + t04 = c ^ t02; \ + t05 = a | t04; \ + t06 = t01 & t05; \ + t07 = d | t03; \ + t08 = b ^ t06; \ + t09 = t07 ^ t06; \ + t10 = t04 | t03; \ + t11 = d & t08; \ + y = ~ t09; \ + x = t10 ^ t11; \ + t14 = a | y ; \ + t15 = t06 ^ x ; \ + z = t01 ^ t04; \ + t17 = c ^ t15; \ + w = t14 ^ t17; \ + } + +#define SBOX2(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t05, t06, t07, t08; \ + u32 t09, t10, t12, t13, t14, t01; \ + t01 = a | c ; \ + t02 = a ^ b ; \ + t03 = d ^ t01; \ + w = t02 ^ t03; \ + t05 = c ^ w ; \ + t06 = b ^ t05; \ + t07 = b | t05; \ + t08 = t01 & t06; \ + t09 = t03 ^ t07; \ + t10 = t02 | t09; \ + x = t10 ^ t08; \ + t12 = a | d ; \ + t13 = t09 ^ x ; \ + t14 = b ^ t13; \ + z = ~ t09; \ + y = t12 ^ t14; \ + } + +#define SBOX2_INVERSE(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t06, t07, t08, t09; \ + u32 t10, t11, t12, t15, t16, t17, t01; \ + t01 = a ^ d ; \ + t02 = c ^ d ; \ + t03 = a & c ; \ + t04 = b | t02; \ + w = t01 ^ t04; \ + t06 = a | c ; \ + t07 = d | w ; \ + t08 = ~ d ; \ + t09 = b & t06; \ + t10 = t08 | t03; \ + t11 = b & t07; \ + t12 = t06 & t02; \ + z = t09 ^ t10; \ + x = t12 ^ t11; \ + t15 = c & z ; \ + t16 = w ^ x ; \ + t17 = t10 ^ t15; \ + y = t16 ^ t17; \ + } + +#define SBOX3(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t06, t07, t08; \ + u32 t09, t10, t11, t13, t14, t15, t01; \ + t01 = a ^ c ; \ + t02 = a | d ; \ + t03 = a & d ; \ + t04 = t01 & t02; \ + t05 = b | t03; \ + t06 = a & b ; \ + t07 = d ^ t04; \ + t08 = c | t06; \ + t09 = b ^ t07; \ + t10 = d & t05; \ + t11 = t02 ^ t10; \ + z = t08 ^ t09; \ + t13 = d | z ; \ + t14 = a | t07; \ + t15 = b & t13; \ + y = t08 ^ t11; \ + w = t14 ^ t15; \ + x = t05 ^ t04; \ + } + +#define SBOX3_INVERSE(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t06, t07, t09; \ + u32 t11, t12, t13, t14, t16, t01; \ + t01 = c | d ; \ + t02 = a | d ; \ + t03 = c ^ t02; \ + t04 = b ^ t02; \ + t05 = a ^ d ; \ + t06 = t04 & t03; \ + t07 = b & t01; \ + y = t05 ^ t06; \ + t09 = a ^ t03; \ + w = t07 ^ t03; \ + t11 = w | t05; \ + t12 = t09 & t11; \ + t13 = a & y ; \ + t14 = t01 ^ t05; \ + x = b ^ t12; \ + t16 = b | t13; \ + z = t14 ^ t16; \ + } + +#define SBOX4(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t06, t08, t09; \ + u32 t10, t11, t12, t13, t14, t15, t16, t01; \ + t01 = a | b ; \ + t02 = b | c ; \ + t03 = a ^ t02; \ + t04 = b ^ d ; \ + t05 = d | t03; \ + t06 = d & t01; \ + z = t03 ^ t06; \ + t08 = z & t04; \ + t09 = t04 & t05; \ + t10 = c ^ t06; \ + t11 = b & c ; \ + t12 = t04 ^ t08; \ + t13 = t11 | t03; \ + t14 = t10 ^ t09; \ + t15 = a & t05; \ + t16 = t11 | t12; \ + y = t13 ^ t08; \ + x = t15 ^ t16; \ + w = ~ t14; \ + } + +#define SBOX4_INVERSE(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t06, t07, t09; \ + u32 t10, t11, t12, t13, t15, t01; \ + t01 = b | d ; \ + t02 = c | d ; \ + t03 = a & t01; \ + t04 = b ^ t02; \ + t05 = c ^ d ; \ + t06 = ~ t03; \ + t07 = a & t04; \ + x = t05 ^ t07; \ + t09 = x | t06; \ + t10 = a ^ t07; \ + t11 = t01 ^ t09; \ + t12 = d ^ t04; \ + t13 = c | t10; \ + z = t03 ^ t12; \ + t15 = a ^ t04; \ + y = t11 ^ t13; \ + w = t15 ^ t09; \ + } + +#define SBOX5(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t07, t08, t09; \ + u32 t10, t11, t12, t13, t14, t01; \ + t01 = b ^ d ; \ + t02 = b | d ; \ + t03 = a & t01; \ + t04 = c ^ t02; \ + t05 = t03 ^ t04; \ + w = ~ t05; \ + t07 = a ^ t01; \ + t08 = d | w ; \ + t09 = b | t05; \ + t10 = d ^ t08; \ + t11 = b | t07; \ + t12 = t03 | w ; \ + t13 = t07 | t10; \ + t14 = t01 ^ t11; \ + y = t09 ^ t13; \ + x = t07 ^ t08; \ + z = t12 ^ t14; \ + } + +#define SBOX5_INVERSE(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t07, t08, t09; \ + u32 t10, t12, t13, t15, t16, t01; \ + t01 = a & d ; \ + t02 = c ^ t01; \ + t03 = a ^ d ; \ + t04 = b & t02; \ + t05 = a & c ; \ + w = t03 ^ t04; \ + t07 = a & w ; \ + t08 = t01 ^ w ; \ + t09 = b | t05; \ + t10 = ~ b ; \ + x = t08 ^ t09; \ + t12 = t10 | t07; \ + t13 = w | x ; \ + z = t02 ^ t12; \ + t15 = t02 ^ t13; \ + t16 = b ^ d ; \ + y = t16 ^ t15; \ + } + +#define SBOX6(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t07, t08, t09, t10; \ + u32 t11, t12, t13, t15, t17, t18, t01; \ + t01 = a & d ; \ + t02 = b ^ c ; \ + t03 = a ^ d ; \ + t04 = t01 ^ t02; \ + t05 = b | c ; \ + x = ~ t04; \ + t07 = t03 & t05; \ + t08 = b & x ; \ + t09 = a | c ; \ + t10 = t07 ^ t08; \ + t11 = b | d ; \ + t12 = c ^ t11; \ + t13 = t09 ^ t10; \ + y = ~ t13; \ + t15 = x & t03; \ + z = t12 ^ t07; \ + t17 = a ^ b ; \ + t18 = y ^ t15; \ + w = t17 ^ t18; \ + } + +#define SBOX6_INVERSE(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t06, t07, t08, t09; \ + u32 t12, t13, t14, t15, t16, t17, t01; \ + t01 = a ^ c ; \ + t02 = ~ c ; \ + t03 = b & t01; \ + t04 = b | t02; \ + t05 = d | t03; \ + t06 = b ^ d ; \ + t07 = a & t04; \ + t08 = a | t02; \ + t09 = t07 ^ t05; \ + x = t06 ^ t08; \ + w = ~ t09; \ + t12 = b & w ; \ + t13 = t01 & t05; \ + t14 = t01 ^ t12; \ + t15 = t07 ^ t13; \ + t16 = d | t02; \ + t17 = a ^ x ; \ + z = t17 ^ t15; \ + y = t16 ^ t14; \ + } + +#define SBOX7(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t05, t06, t08, t09, t10; \ + u32 t11, t13, t14, t15, t16, t17, t01; \ + t01 = a & c ; \ + t02 = ~ d ; \ + t03 = a & t02; \ + t04 = b | t01; \ + t05 = a & b ; \ + t06 = c ^ t04; \ + z = t03 ^ t06; \ + t08 = c | z ; \ + t09 = d | t05; \ + t10 = a ^ t08; \ + t11 = t04 & z ; \ + x = t09 ^ t10; \ + t13 = b ^ x ; \ + t14 = t01 ^ x ; \ + t15 = c ^ t05; \ + t16 = t11 | t13; \ + t17 = t02 | t14; \ + w = t15 ^ t17; \ + y = a ^ t16; \ + } + +#define SBOX7_INVERSE(a, b, c, d, w, x, y, z) \ + { \ + u32 t02, t03, t04, t06, t07, t08, t09; \ + u32 t10, t11, t13, t14, t15, t16, t01; \ + t01 = a & b ; \ + t02 = a | b ; \ + t03 = c | t01; \ + t04 = d & t02; \ + z = t03 ^ t04; \ + t06 = b ^ t04; \ + t07 = d ^ z ; \ + t08 = ~ t07; \ + t09 = t06 | t08; \ + t10 = b ^ d ; \ + t11 = a | d ; \ + x = a ^ t09; \ + t13 = c ^ t06; \ + t14 = c & t11; \ + t15 = d | x ; \ + t16 = t01 | t10; \ + w = t13 ^ t15; \ + y = t14 ^ t16; \ + } + +/* XOR BLOCK1 into BLOCK0. */ +#define BLOCK_XOR(block0, block1) \ + { \ + block0[0] ^= block1[0]; \ + block0[1] ^= block1[1]; \ + block0[2] ^= block1[2]; \ + block0[3] ^= block1[3]; \ + } + +/* Copy BLOCK_SRC to BLOCK_DST. */ +#define BLOCK_COPY(block_dst, block_src) \ + { \ + block_dst[0] = block_src[0]; \ + block_dst[1] = block_src[1]; \ + block_dst[2] = block_src[2]; \ + block_dst[3] = block_src[3]; \ + } + +/* Apply SBOX number WHICH to to the block found in ARRAY0 at index + INDEX, writing the output to the block found in ARRAY1 at index + INDEX. */ +#define SBOX(which, array0, array1, index) \ + SBOX##which (array0[index + 0], array0[index + 1], \ + array0[index + 2], array0[index + 3], \ + array1[index + 0], array1[index + 1], \ + array1[index + 2], array1[index + 3]); + +/* Apply inverse SBOX number WHICH to to the block found in ARRAY0 at + index INDEX, writing the output to the block found in ARRAY1 at + index INDEX. */ +#define SBOX_INVERSE(which, array0, array1, index) \ + SBOX##which##_INVERSE (array0[index + 0], array0[index + 1], \ + array0[index + 2], array0[index + 3], \ + array1[index + 0], array1[index + 1], \ + array1[index + 2], array1[index + 3]); + +/* Apply the linear transformation to BLOCK. */ +#define LINEAR_TRANSFORMATION(block) \ + { \ + block[0] = rol (block[0], 13); \ + block[2] = rol (block[2], 3); \ + block[1] = block[1] ^ block[0] ^ block[2]; \ + block[3] = block[3] ^ block[2] ^ (block[0] << 3); \ + block[1] = rol (block[1], 1); \ + block[3] = rol (block[3], 7); \ + block[0] = block[0] ^ block[1] ^ block[3]; \ + block[2] = block[2] ^ block[3] ^ (block[1] << 7); \ + block[0] = rol (block[0], 5); \ + block[2] = rol (block[2], 22); \ + } + +/* Apply the inverse linear transformation to BLOCK. */ +#define LINEAR_TRANSFORMATION_INVERSE(block) \ + { \ + block[2] = ror (block[2], 22); \ + block[0] = ror (block[0] , 5); \ + block[2] = block[2] ^ block[3] ^ (block[1] << 7); \ + block[0] = block[0] ^ block[1] ^ block[3]; \ + block[3] = ror (block[3], 7); \ + block[1] = ror (block[1], 1); \ + block[3] = block[3] ^ block[2] ^ (block[0] << 3); \ + block[1] = block[1] ^ block[0] ^ block[2]; \ + block[2] = ror (block[2], 3); \ + block[0] = ror (block[0], 13); \ + } + +/* Apply a Serpent round to BLOCK, using the SBOX number WHICH and the + subkeys contained in SUBKEYS. Use BLOCK_TMP as temporary storage. + This macro increments `round'. */ +#define ROUND(which, subkeys, block, block_tmp) \ + { \ + BLOCK_XOR (block, subkeys[round]); \ + round++; \ + SBOX (which, block, block_tmp, 0); \ + LINEAR_TRANSFORMATION (block_tmp); \ + BLOCK_COPY (block, block_tmp); \ + } + +/* Apply the last Serpent round to BLOCK, using the SBOX number WHICH + and the subkeys contained in SUBKEYS. Use BLOCK_TMP as temporary + storage. The result will be stored in BLOCK_TMP. This macro + increments `round'. */ +#define ROUND_LAST(which, subkeys, block, block_tmp) \ + { \ + BLOCK_XOR (block, subkeys[round]); \ + round++; \ + SBOX (which, block, block_tmp, 0); \ + BLOCK_XOR (block_tmp, subkeys[round]); \ + round++; \ + } + +/* Apply an inverse Serpent round to BLOCK, using the SBOX number + WHICH and the subkeys contained in SUBKEYS. Use BLOCK_TMP as + temporary storage. This macro increments `round'. */ +#define ROUND_INVERSE(which, subkey, block, block_tmp) \ + { \ + LINEAR_TRANSFORMATION_INVERSE (block); \ + SBOX_INVERSE (which, block, block_tmp, 0); \ + BLOCK_XOR (block_tmp, subkey[round]); \ + round--; \ + BLOCK_COPY (block, block_tmp); \ + } + +/* Apply the first Serpent round to BLOCK, using the SBOX number WHICH + and the subkeys contained in SUBKEYS. Use BLOCK_TMP as temporary + storage. The result will be stored in BLOCK_TMP. This macro + increments `round'. */ +#define ROUND_FIRST_INVERSE(which, subkeys, block, block_tmp) \ + { \ + BLOCK_XOR (block, subkeys[round]); \ + round--; \ + SBOX_INVERSE (which, block, block_tmp, 0); \ + BLOCK_XOR (block_tmp, subkeys[round]); \ + round--; \ + } + +/* Convert the user provided key KEY of KEY_LENGTH bytes into the + internally used format. */ +static void +serpent_key_prepare (const byte *key, unsigned int key_length, + serpent_key_t key_prepared) +{ + int i; + + /* Copy key. */ + for (i = 0; i < key_length / 4; i++) + { +#ifdef WORDS_BIGENDIAN + key_prepared[i] = byte_swap_32 (((u32 *) key)[i]); +#else + key_prepared[i] = ((u32 *) key)[i]; +#endif + } + + if (i < 8) + { + /* Key must be padded according to the Serpent + specification. */ + key_prepared[i] = 0x00000001; + + for (i++; i < 8; i++) + key_prepared[i] = 0; + } +} + +/* Derive the 33 subkeys from KEY and store them in SUBKEYS. */ +static void +serpent_subkeys_generate (serpent_key_t key, serpent_subkeys_t subkeys) +{ + u32 w_real[140]; /* The `prekey'. */ + u32 k[132]; + u32 *w = &w_real[8]; + int i, j; + + /* Initialize with key values. */ + for (i = 0; i < 8; i++) + w[i - 8] = key[i]; + + /* Expand to intermediate key using the affine recurrence. */ + for (i = 0; i < 132; i++) + w[i] = rol (w[i - 8] ^ w[i - 5] ^ w[i - 3] ^ w[i - 1] ^ PHI ^ i, 11); + + /* Calculate subkeys via S-Boxes, in bitslice mode. */ + SBOX (3, w, k, 0); + SBOX (2, w, k, 4); + SBOX (1, w, k, 8); + SBOX (0, w, k, 12); + SBOX (7, w, k, 16); + SBOX (6, w, k, 20); + SBOX (5, w, k, 24); + SBOX (4, w, k, 28); + SBOX (3, w, k, 32); + SBOX (2, w, k, 36); + SBOX (1, w, k, 40); + SBOX (0, w, k, 44); + SBOX (7, w, k, 48); + SBOX (6, w, k, 52); + SBOX (5, w, k, 56); + SBOX (4, w, k, 60); + SBOX (3, w, k, 64); + SBOX (2, w, k, 68); + SBOX (1, w, k, 72); + SBOX (0, w, k, 76); + SBOX (7, w, k, 80); + SBOX (6, w, k, 84); + SBOX (5, w, k, 88); + SBOX (4, w, k, 92); + SBOX (3, w, k, 96); + SBOX (2, w, k, 100); + SBOX (1, w, k, 104); + SBOX (0, w, k, 108); + SBOX (7, w, k, 112); + SBOX (6, w, k, 116); + SBOX (5, w, k, 120); + SBOX (4, w, k, 124); + SBOX (3, w, k, 128); + + /* Renumber subkeys. */ + for (i = 0; i < ROUNDS + 1; i++) + for (j = 0; j < 4; j++) + subkeys[i][j] = k[4 * i + j]; +} + +/* Initialize CONTEXT with the key KEY of KEY_LENGTH bits. */ +static void +serpent_setkey_internal (serpent_context_t *context, + const byte *key, unsigned int key_length) +{ + serpent_key_t key_prepared; + + serpent_key_prepare (key, key_length, key_prepared); + serpent_subkeys_generate (key_prepared, context->keys); + _gcry_burn_stack (272 * sizeof (u32)); +} + +/* Initialize CTX with the key KEY of KEY_LENGTH bytes. */ +static gcry_err_code_t +serpent_setkey (void *ctx, + const byte *key, unsigned int key_length) +{ + serpent_context_t *context = ctx; + static const char *serpent_test_ret; + static int serpent_init_done; + gcry_err_code_t ret = GPG_ERR_NO_ERROR; + + if (! serpent_init_done) + { + /* Execute a self-test the first time, Serpent is used. */ + serpent_test_ret = serpent_test (); + if (serpent_test_ret) + log_error ("Serpent test failure: %s\n", serpent_test_ret); + serpent_init_done = 1; + } + + if (serpent_test_ret) + ret = GPG_ERR_SELFTEST_FAILED; + else + { + serpent_setkey_internal (context, key, key_length); + _gcry_burn_stack (sizeof (serpent_key_t)); + } + + return ret; +} + +static void +serpent_encrypt_internal (serpent_context_t *context, + const serpent_block_t input, serpent_block_t output) +{ + serpent_block_t b, b_next; + int round = 0; + +#ifdef WORDS_BIGENDIAN + b[0] = byte_swap_32 (input[0]); + b[1] = byte_swap_32 (input[1]); + b[2] = byte_swap_32 (input[2]); + b[3] = byte_swap_32 (input[3]); +#else + b[0] = input[0]; + b[1] = input[1]; + b[2] = input[2]; + b[3] = input[3]; +#endif + + ROUND (0, context->keys, b, b_next); + ROUND (1, context->keys, b, b_next); + ROUND (2, context->keys, b, b_next); + ROUND (3, context->keys, b, b_next); + ROUND (4, context->keys, b, b_next); + ROUND (5, context->keys, b, b_next); + ROUND (6, context->keys, b, b_next); + ROUND (7, context->keys, b, b_next); + ROUND (0, context->keys, b, b_next); + ROUND (1, context->keys, b, b_next); + ROUND (2, context->keys, b, b_next); + ROUND (3, context->keys, b, b_next); + ROUND (4, context->keys, b, b_next); + ROUND (5, context->keys, b, b_next); + ROUND (6, context->keys, b, b_next); + ROUND (7, context->keys, b, b_next); + ROUND (0, context->keys, b, b_next); + ROUND (1, context->keys, b, b_next); + ROUND (2, context->keys, b, b_next); + ROUND (3, context->keys, b, b_next); + ROUND (4, context->keys, b, b_next); + ROUND (5, context->keys, b, b_next); + ROUND (6, context->keys, b, b_next); + ROUND (7, context->keys, b, b_next); + ROUND (0, context->keys, b, b_next); + ROUND (1, context->keys, b, b_next); + ROUND (2, context->keys, b, b_next); + ROUND (3, context->keys, b, b_next); + ROUND (4, context->keys, b, b_next); + ROUND (5, context->keys, b, b_next); + ROUND (6, context->keys, b, b_next); + + ROUND_LAST (7, context->keys, b, b_next); + +#ifdef WORDS_BIGENDIAN + output[0] = byte_swap_32 (b_next[0]); + output[1] = byte_swap_32 (b_next[1]); + output[2] = byte_swap_32 (b_next[2]); + output[3] = byte_swap_32 (b_next[3]); +#else + output[0] = b_next[0]; + output[1] = b_next[1]; + output[2] = b_next[2]; + output[3] = b_next[3]; +#endif +} + +static void +serpent_decrypt_internal (serpent_context_t *context, + const serpent_block_t input, serpent_block_t output) +{ + serpent_block_t b, b_next; + int round = ROUNDS; + +#ifdef WORDS_BIGENDIAN + b_next[0] = byte_swap_32 (input[0]); + b_next[1] = byte_swap_32 (input[1]); + b_next[2] = byte_swap_32 (input[2]); + b_next[3] = byte_swap_32 (input[3]); +#else + b_next[0] = input[0]; + b_next[1] = input[1]; + b_next[2] = input[2]; + b_next[3] = input[3]; +#endif + + ROUND_FIRST_INVERSE (7, context->keys, b_next, b); + + ROUND_INVERSE (6, context->keys, b, b_next); + ROUND_INVERSE (5, context->keys, b, b_next); + ROUND_INVERSE (4, context->keys, b, b_next); + ROUND_INVERSE (3, context->keys, b, b_next); + ROUND_INVERSE (2, context->keys, b, b_next); + ROUND_INVERSE (1, context->keys, b, b_next); + ROUND_INVERSE (0, context->keys, b, b_next); + ROUND_INVERSE (7, context->keys, b, b_next); + ROUND_INVERSE (6, context->keys, b, b_next); + ROUND_INVERSE (5, context->keys, b, b_next); + ROUND_INVERSE (4, context->keys, b, b_next); + ROUND_INVERSE (3, context->keys, b, b_next); + ROUND_INVERSE (2, context->keys, b, b_next); + ROUND_INVERSE (1, context->keys, b, b_next); + ROUND_INVERSE (0, context->keys, b, b_next); + ROUND_INVERSE (7, context->keys, b, b_next); + ROUND_INVERSE (6, context->keys, b, b_next); + ROUND_INVERSE (5, context->keys, b, b_next); + ROUND_INVERSE (4, context->keys, b, b_next); + ROUND_INVERSE (3, context->keys, b, b_next); + ROUND_INVERSE (2, context->keys, b, b_next); + ROUND_INVERSE (1, context->keys, b, b_next); + ROUND_INVERSE (0, context->keys, b, b_next); + ROUND_INVERSE (7, context->keys, b, b_next); + ROUND_INVERSE (6, context->keys, b, b_next); + ROUND_INVERSE (5, context->keys, b, b_next); + ROUND_INVERSE (4, context->keys, b, b_next); + ROUND_INVERSE (3, context->keys, b, b_next); + ROUND_INVERSE (2, context->keys, b, b_next); + ROUND_INVERSE (1, context->keys, b, b_next); + ROUND_INVERSE (0, context->keys, b, b_next); + + +#ifdef WORDS_BIGENDIAN + output[0] = byte_swap_32 (b_next[0]); + output[1] = byte_swap_32 (b_next[1]); + output[2] = byte_swap_32 (b_next[2]); + output[3] = byte_swap_32 (b_next[3]); +#else + output[0] = b_next[0]; + output[1] = b_next[1]; + output[2] = b_next[2]; + output[3] = b_next[3]; +#endif +} + +static void +serpent_encrypt (void *ctx, byte *buffer_out, const byte *buffer_in) +{ + serpent_context_t *context = ctx; + + serpent_encrypt_internal (context, + (const u32 *) buffer_in, (u32 *) buffer_out); + _gcry_burn_stack (2 * sizeof (serpent_block_t)); +} + +static void +serpent_decrypt (void *ctx, byte *buffer_out, const byte *buffer_in) +{ + serpent_context_t *context = ctx; + + serpent_decrypt_internal (context, + (const u32 *) buffer_in, + (u32 *) buffer_out); + _gcry_burn_stack (2 * sizeof (serpent_block_t)); +} + + + +/* Serpent test. */ + +static const char * +serpent_test (void) +{ + serpent_context_t context; + unsigned char scratch[16]; + unsigned int i; + + static struct test + { + int key_length; + unsigned char key[32]; + unsigned char text_plain[16]; + unsigned char text_cipher[16]; + } test_data[] = + { + { + 16, + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", + "\xD2\x9D\x57\x6F\xCE\xA3\xA3\xA7\xED\x90\x99\xF2\x92\x73\xD7\x8E", + "\xB2\x28\x8B\x96\x8A\xE8\xB0\x86\x48\xD1\xCE\x96\x06\xFD\x99\x2D" + }, + { + 24, + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00", + "\xD2\x9D\x57\x6F\xCE\xAB\xA3\xA7\xED\x98\x99\xF2\x92\x7B\xD7\x8E", + "\x13\x0E\x35\x3E\x10\x37\xC2\x24\x05\xE8\xFA\xEF\xB2\xC3\xC3\xE9" + }, + { + 32, + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", + "\xD0\x95\x57\x6F\xCE\xA3\xE3\xA7\xED\x98\xD9\xF2\x90\x73\xD7\x8E", + "\xB9\x0E\xE5\x86\x2D\xE6\x91\x68\xF2\xBD\xD5\x12\x5B\x45\x47\x2B" + }, + { + 32, + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", + "\x00\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00\x03\x00\x00\x00", + "\x20\x61\xA4\x27\x82\xBD\x52\xEC\x69\x1E\xC3\x83\xB0\x3B\xA7\x7C" + }, + { + 0 + }, + }; + + for (i = 0; test_data[i].key_length; i++) + { + serpent_setkey_internal (&context, test_data[i].key, + test_data[i].key_length); + serpent_encrypt_internal (&context, + (const u32 *) test_data[i].text_plain, + (u32 *) scratch); + + if (memcmp (scratch, test_data[i].text_cipher, sizeof (serpent_block_t))) + switch (test_data[i].key_length) + { + case 16: + return "Serpent-128 test encryption failed."; + case 24: + return "Serpent-192 test encryption failed."; + case 32: + return "Serpent-256 test encryption failed."; + } + + serpent_decrypt_internal (&context, + (const u32 *) test_data[i].text_cipher, + (u32 *) scratch); + if (memcmp (scratch, test_data[i].text_plain, sizeof (serpent_block_t))) + switch (test_data[i].key_length) + { + case 16: + return "Serpent-128 test decryption failed."; + case 24: + return "Serpent-192 test decryption failed."; + case 32: + return "Serpent-256 test decryption failed."; + } + } + + return NULL; +} + + + +/* "SERPENT" is an alias for "SERPENT128". */ +static const char *cipher_spec_serpent128_aliases[] = + { + "SERPENT", + NULL + }; + +gcry_cipher_spec_t _gcry_cipher_spec_serpent128 = + { + "SERPENT128", cipher_spec_serpent128_aliases, NULL, 16, 128, + sizeof (serpent_context_t), + serpent_setkey, serpent_encrypt, serpent_decrypt + }; + +gcry_cipher_spec_t _gcry_cipher_spec_serpent192 = + { + "SERPENT192", NULL, NULL, 16, 192, + sizeof (serpent_context_t), + serpent_setkey, serpent_encrypt, serpent_decrypt + }; + +gcry_cipher_spec_t _gcry_cipher_spec_serpent256 = + { + "SERPENT256", NULL, NULL, 16, 256, + sizeof (serpent_context_t), + serpent_setkey, serpent_encrypt, serpent_decrypt + }; |