diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-04 18:23:14 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-04 18:23:14 -0400 |
| commit | b7c8e55db7141dcbb9d5305a3260fa0ed62a1bcc (patch) | |
| tree | 59fbd52d8e80e5a83d9747961d28aaf4d400613a /crypto/twofish_generic.c | |
| parent | ffd386a9a8273dcfa61705d0b349eebc7525ef87 (diff) | |
| parent | 4015d9a865e3bcc42d88bedc8ce1551000bab664 (diff) | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (39 commits)
random: Reorder struct entropy_store to remove padding on 64bits
padata: update API documentation
padata: Remove padata_get_cpumask
crypto: pcrypt - Update pcrypt cpumask according to the padata cpumask notifier
crypto: pcrypt - Rename pcrypt_instance
padata: Pass the padata cpumasks to the cpumask_change_notifier chain
padata: Rearrange set_cpumask functions
padata: Rename padata_alloc functions
crypto: pcrypt - Dont calulate a callback cpu on empty callback cpumask
padata: Check for valid cpumasks
padata: Allocate cpumask dependend recources in any case
padata: Fix cpu index counting
crypto: geode_aes - Convert pci_table entries to PCI_VDEVICE (if PCI_ANY_ID is used)
pcrypt: Added sysfs interface to pcrypt
padata: Added sysfs primitives to padata subsystem
padata: Make two separate cpumasks
padata: update documentation
padata: simplify serialization mechanism
padata: make padata_do_parallel to return zero on success
padata: Handle empty padata cpumasks
...
Diffstat (limited to 'crypto/twofish_generic.c')
| -rw-r--r-- | crypto/twofish_generic.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/crypto/twofish_generic.c b/crypto/twofish_generic.c new file mode 100644 index 000000000000..1f07b843e07c --- /dev/null +++ b/crypto/twofish_generic.c | |||
| @@ -0,0 +1,215 @@ | |||
| 1 | /* | ||
| 2 | * Twofish for CryptoAPI | ||
| 3 | * | ||
| 4 | * Originally Twofish for GPG | ||
| 5 | * By Matthew Skala <mskala@ansuz.sooke.bc.ca>, July 26, 1998 | ||
| 6 | * 256-bit key length added March 20, 1999 | ||
| 7 | * Some modifications to reduce the text size by Werner Koch, April, 1998 | ||
| 8 | * Ported to the kerneli patch by Marc Mutz <Marc@Mutz.com> | ||
| 9 | * Ported to CryptoAPI by Colin Slater <hoho@tacomeat.net> | ||
| 10 | * | ||
| 11 | * The original author has disclaimed all copyright interest in this | ||
| 12 | * code and thus put it in the public domain. The subsequent authors | ||
| 13 | * have put this under the GNU General Public License. | ||
| 14 | * | ||
| 15 | * This program is free software; you can redistribute it and/or modify | ||
| 16 | * it under the terms of the GNU General Public License as published by | ||
| 17 | * the Free Software Foundation; either version 2 of the License, or | ||
| 18 | * (at your option) any later version. | ||
| 19 | * | ||
| 20 | * This program is distributed in the hope that it will be useful, | ||
| 21 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 22 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| 23 | * GNU General Public License for more details. | ||
| 24 | * | ||
| 25 | * You should have received a copy of the GNU General Public License | ||
| 26 | * along with this program; if not, write to the Free Software | ||
| 27 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | ||
| 28 | * USA | ||
| 29 | * | ||
| 30 | * This code is a "clean room" implementation, written from the paper | ||
| 31 | * _Twofish: A 128-Bit Block Cipher_ by Bruce Schneier, John Kelsey, | ||
| 32 | * Doug Whiting, David Wagner, Chris Hall, and Niels Ferguson, available | ||
| 33 | * through http://www.counterpane.com/twofish.html | ||
| 34 | * | ||
| 35 | * For background information on multiplication in finite fields, used for | ||
| 36 | * the matrix operations in the key schedule, see the book _Contemporary | ||
| 37 | * Abstract Algebra_ by Joseph A. Gallian, especially chapter 22 in the | ||
| 38 | * Third Edition. | ||
| 39 | */ | ||
| 40 | |||
| 41 | #include <asm/byteorder.h> | ||
| 42 | #include <crypto/twofish.h> | ||
| 43 | #include <linux/module.h> | ||
| 44 | #include <linux/init.h> | ||
| 45 | #include <linux/types.h> | ||
| 46 | #include <linux/errno.h> | ||
| 47 | #include <linux/crypto.h> | ||
| 48 | #include <linux/bitops.h> | ||
| 49 | |||
| 50 | /* Macros to compute the g() function in the encryption and decryption | ||
| 51 | * rounds. G1 is the straight g() function; G2 includes the 8-bit | ||
| 52 | * rotation for the high 32-bit word. */ | ||
| 53 | |||
| 54 | #define G1(a) \ | ||
| 55 | (ctx->s[0][(a) & 0xFF]) ^ (ctx->s[1][((a) >> 8) & 0xFF]) \ | ||
| 56 | ^ (ctx->s[2][((a) >> 16) & 0xFF]) ^ (ctx->s[3][(a) >> 24]) | ||
| 57 | |||
| 58 | #define G2(b) \ | ||
| 59 | (ctx->s[1][(b) & 0xFF]) ^ (ctx->s[2][((b) >> 8) & 0xFF]) \ | ||
| 60 | ^ (ctx->s[3][((b) >> 16) & 0xFF]) ^ (ctx->s[0][(b) >> 24]) | ||
| 61 | |||
| 62 | /* Encryption and decryption Feistel rounds. Each one calls the two g() | ||
| 63 | * macros, does the PHT, and performs the XOR and the appropriate bit | ||
| 64 | * rotations. The parameters are the round number (used to select subkeys), | ||
| 65 | * and the four 32-bit chunks of the text. */ | ||
| 66 | |||
| 67 | #define ENCROUND(n, a, b, c, d) \ | ||
| 68 | x = G1 (a); y = G2 (b); \ | ||
| 69 | x += y; y += x + ctx->k[2 * (n) + 1]; \ | ||
| 70 | (c) ^= x + ctx->k[2 * (n)]; \ | ||
| 71 | (c) = ror32((c), 1); \ | ||
| 72 | (d) = rol32((d), 1) ^ y | ||
| 73 | |||
| 74 | #define DECROUND(n, a, b, c, d) \ | ||
| 75 | x = G1 (a); y = G2 (b); \ | ||
| 76 | x += y; y += x; \ | ||
| 77 | (d) ^= y + ctx->k[2 * (n) + 1]; \ | ||
| 78 | (d) = ror32((d), 1); \ | ||
| 79 | (c) = rol32((c), 1); \ | ||
| 80 | (c) ^= (x + ctx->k[2 * (n)]) | ||
| 81 | |||
| 82 | /* Encryption and decryption cycles; each one is simply two Feistel rounds | ||
| 83 | * with the 32-bit chunks re-ordered to simulate the "swap" */ | ||
| 84 | |||
| 85 | #define ENCCYCLE(n) \ | ||
| 86 | ENCROUND (2 * (n), a, b, c, d); \ | ||
| 87 | ENCROUND (2 * (n) + 1, c, d, a, b) | ||
| 88 | |||
| 89 | #define DECCYCLE(n) \ | ||
| 90 | DECROUND (2 * (n) + 1, c, d, a, b); \ | ||
| 91 | DECROUND (2 * (n), a, b, c, d) | ||
| 92 | |||
| 93 | /* Macros to convert the input and output bytes into 32-bit words, | ||
| 94 | * and simultaneously perform the whitening step. INPACK packs word | ||
| 95 | * number n into the variable named by x, using whitening subkey number m. | ||
| 96 | * OUTUNPACK unpacks word number n from the variable named by x, using | ||
| 97 | * whitening subkey number m. */ | ||
| 98 | |||
| 99 | #define INPACK(n, x, m) \ | ||
| 100 | x = le32_to_cpu(src[n]) ^ ctx->w[m] | ||
| 101 | |||
| 102 | #define OUTUNPACK(n, x, m) \ | ||
| 103 | x ^= ctx->w[m]; \ | ||
| 104 | dst[n] = cpu_to_le32(x) | ||
| 105 | |||
| 106 | |||
| 107 | |||
| 108 | /* Encrypt one block. in and out may be the same. */ | ||
| 109 | static void twofish_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) | ||
| 110 | { | ||
| 111 | struct twofish_ctx *ctx = crypto_tfm_ctx(tfm); | ||
| 112 | const __le32 *src = (const __le32 *)in; | ||
| 113 | __le32 *dst = (__le32 *)out; | ||
| 114 | |||
| 115 | /* The four 32-bit chunks of the text. */ | ||
| 116 | u32 a, b, c, d; | ||
| 117 | |||
| 118 | /* Temporaries used by the round function. */ | ||
| 119 | u32 x, y; | ||
| 120 | |||
| 121 | /* Input whitening and packing. */ | ||
| 122 | INPACK (0, a, 0); | ||
| 123 | INPACK (1, b, 1); | ||
| 124 | INPACK (2, c, 2); | ||
| 125 | INPACK (3, d, 3); | ||
| 126 | |||
| 127 | /* Encryption Feistel cycles. */ | ||
| 128 | ENCCYCLE (0); | ||
| 129 | ENCCYCLE (1); | ||
| 130 | ENCCYCLE (2); | ||
| 131 | ENCCYCLE (3); | ||
| 132 | ENCCYCLE (4); | ||
| 133 | ENCCYCLE (5); | ||
| 134 | ENCCYCLE (6); | ||
| 135 | ENCCYCLE (7); | ||
| 136 | |||
| 137 | /* Output whitening and unpacking. */ | ||
| 138 | OUTUNPACK (0, c, 4); | ||
| 139 | OUTUNPACK (1, d, 5); | ||
| 140 | OUTUNPACK (2, a, 6); | ||
| 141 | OUTUNPACK (3, b, 7); | ||
| 142 | |||
| 143 | } | ||
| 144 | |||
| 145 | /* Decrypt one block. in and out may be the same. */ | ||
| 146 | static void twofish_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) | ||
| 147 | { | ||
| 148 | struct twofish_ctx *ctx = crypto_tfm_ctx(tfm); | ||
| 149 | const __le32 *src = (const __le32 *)in; | ||
| 150 | __le32 *dst = (__le32 *)out; | ||
| 151 | |||
| 152 | /* The four 32-bit chunks of the text. */ | ||
| 153 | u32 a, b, c, d; | ||
| 154 | |||
| 155 | /* Temporaries used by the round function. */ | ||
| 156 | u32 x, y; | ||
| 157 | |||
| 158 | /* Input whitening and packing. */ | ||
| 159 | INPACK (0, c, 4); | ||
| 160 | INPACK (1, d, 5); | ||
| 161 | INPACK (2, a, 6); | ||
| 162 | INPACK (3, b, 7); | ||
| 163 | |||
| 164 | /* Encryption Feistel cycles. */ | ||
| 165 | DECCYCLE (7); | ||
| 166 | DECCYCLE (6); | ||
| 167 | DECCYCLE (5); | ||
| 168 | DECCYCLE (4); | ||
| 169 | DECCYCLE (3); | ||
| 170 | DECCYCLE (2); | ||
| 171 | DECCYCLE (1); | ||
| 172 | DECCYCLE (0); | ||
| 173 | |||
| 174 | /* Output whitening and unpacking. */ | ||
| 175 | OUTUNPACK (0, a, 0); | ||
| 176 | OUTUNPACK (1, b, 1); | ||
| 177 | OUTUNPACK (2, c, 2); | ||
| 178 | OUTUNPACK (3, d, 3); | ||
| 179 | |||
| 180 | } | ||
| 181 | |||
| 182 | static struct crypto_alg alg = { | ||
| 183 | .cra_name = "twofish", | ||
| 184 | .cra_driver_name = "twofish-generic", | ||
| 185 | .cra_priority = 100, | ||
| 186 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, | ||
| 187 | .cra_blocksize = TF_BLOCK_SIZE, | ||
| 188 | .cra_ctxsize = sizeof(struct twofish_ctx), | ||
| 189 | .cra_alignmask = 3, | ||
| 190 | .cra_module = THIS_MODULE, | ||
| 191 | .cra_list = LIST_HEAD_INIT(alg.cra_list), | ||
| 192 | .cra_u = { .cipher = { | ||
| 193 | .cia_min_keysize = TF_MIN_KEY_SIZE, | ||
| 194 | .cia_max_keysize = TF_MAX_KEY_SIZE, | ||
| 195 | .cia_setkey = twofish_setkey, | ||
| 196 | .cia_encrypt = twofish_encrypt, | ||
| 197 | .cia_decrypt = twofish_decrypt } } | ||
| 198 | }; | ||
| 199 | |||
| 200 | static int __init twofish_mod_init(void) | ||
| 201 | { | ||
| 202 | return crypto_register_alg(&alg); | ||
| 203 | } | ||
| 204 | |||
| 205 | static void __exit twofish_mod_fini(void) | ||
| 206 | { | ||
| 207 | crypto_unregister_alg(&alg); | ||
| 208 | } | ||
| 209 | |||
| 210 | module_init(twofish_mod_init); | ||
| 211 | module_exit(twofish_mod_fini); | ||
| 212 | |||
| 213 | MODULE_LICENSE("GPL"); | ||
| 214 | MODULE_DESCRIPTION ("Twofish Cipher Algorithm"); | ||
| 215 | MODULE_ALIAS("twofish"); | ||
