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author | Simon Josefsson <simon@josefsson.org> | 2005-10-21 12:05:30 +0000 |
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committer | Simon Josefsson <simon@josefsson.org> | 2005-10-21 12:05:30 +0000 |
commit | 9232c2a6007644c66da0807b7a33f38074fd5c11 (patch) | |
tree | 8b1cad89c348ddfb7ef181ba7c43210e65c61c8e /gl/arctwo.c | |
parent | ef5bb428423e75e59705ff360ad8f4809bdc33aa (diff) | |
download | gnutls-9232c2a6007644c66da0807b7a33f38074fd5c11.tar.gz |
Update.
Diffstat (limited to 'gl/arctwo.c')
-rw-r--r-- | gl/arctwo.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/gl/arctwo.c b/gl/arctwo.c new file mode 100644 index 0000000000..99d6e86c28 --- /dev/null +++ b/gl/arctwo.c @@ -0,0 +1,231 @@ +/* arctwo.c --- The RC2 cipher as described in RFC 2268. + * Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc. + * + * This file 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, or (at your + * option) any later version. + * + * This file 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 Lesser General Public License + * along with this file; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +/* Code from GnuTLS/Libgcrypt adapted for gnulib by Simon Josefsson. */ + +/* This implementation was written by Nikos Mavroyanopoulos for GNUTLS + * as a Libgcrypt module (gnutls/lib/x509/rc2.c) and later adapted for + * direct use by Libgcrypt by Werner Koch. This implementation is + * only useful for pkcs#12 descryption. + * + * The implementation here is based on Peter Gutmann's RRC.2 paper. + */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include "arctwo.h" + +static const uint8_t arctwo_sbox[] = { + 217, 120, 249, 196, 25, 221, 181, 237, + 40, 233, 253, 121, 74, 160, 216, 157, + 198, 126, 55, 131, 43, 118, 83, 142, + 98, 76, 100, 136, 68, 139, 251, 162, + 23, 154, 89, 245, 135, 179, 79, 19, + 97, 69, 109, 141, 9, 129, 125, 50, + 189, 143, 64, 235, 134, 183, 123, 11, + 240, 149, 33, 34, 92, 107, 78, 130, + 84, 214, 101, 147, 206, 96, 178, 28, + 115, 86, 192, 20, 167, 140, 241, 220, + 18, 117, 202, 31, 59, 190, 228, 209, + 66, 61, 212, 48, 163, 60, 182, 38, + 111, 191, 14, 218, 70, 105, 7, 87, + 39, 242, 29, 155, 188, 148, 67, 3, + 248, 17, 199, 246, 144, 239, 62, 231, + 6, 195, 213, 47, 200, 102, 30, 215, + 8, 232, 234, 222, 128, 82, 238, 247, + 132, 170, 114, 172, 53, 77, 106, 42, + 150, 26, 210, 113, 90, 21, 73, 116, + 75, 159, 208, 94, 4, 24, 164, 236, + 194, 224, 65, 110, 15, 81, 203, 204, + 36, 145, 175, 80, 161, 244, 112, 57, + 153, 124, 58, 133, 35, 184, 180, 122, + 252, 2, 54, 91, 37, 85, 151, 49, + 45, 93, 250, 152, 227, 138, 146, 174, + 5, 223, 41, 16, 103, 108, 186, 201, + 211, 0, 230, 207, 225, 158, 168, 44, + 99, 22, 1, 63, 88, 226, 137, 169, + 13, 56, 52, 27, 171, 51, 255, 176, + 187, 72, 12, 95, 185, 177, 205, 46, + 197, 243, 219, 71, 229, 165, 156, 119, + 10, 166, 32, 104, 254, 127, 193, 173 +}; + +#define rotl16(x,n) (((x) << ((uint16_t)(n))) | ((x) >> (16 - (uint16_t)(n)))) +#define rotr16(x,n) (((x) >> ((uint16_t)(n))) | ((x) << (16 - (uint16_t)(n)))) + +/* C89 compliant way to cast 'char' to 'unsigned char'. */ +static inline unsigned char +to_uchar (char ch) +{ + return ch; +} + +void +arctwo_encrypt (arctwo_context *context, const char *inbuf, + char *outbuf, size_t length) +{ + for (; length >= ARCTWO_BLOCK_SIZE; length -= ARCTWO_BLOCK_SIZE, + inbuf += ARCTWO_BLOCK_SIZE, outbuf += ARCTWO_BLOCK_SIZE) + { + size_t i, j; + uint16_t word0 = 0, word1 = 0, word2 = 0, word3 = 0; + + word0 = (word0 << 8) | to_uchar (inbuf[1]); + word0 = (word0 << 8) | to_uchar (inbuf[0]); + word1 = (word1 << 8) | to_uchar (inbuf[3]); + word1 = (word1 << 8) | to_uchar (inbuf[2]); + word2 = (word2 << 8) | to_uchar (inbuf[5]); + word2 = (word2 << 8) | to_uchar (inbuf[4]); + word3 = (word3 << 8) | to_uchar (inbuf[7]); + word3 = (word3 << 8) | to_uchar (inbuf[6]); + + for (i = 0; i < 16; i++) + { + j = i * 4; + /* For some reason I cannot combine those steps. */ + word0 += (word1 & ~word3) + (word2 & word3) + context->S[j]; + word0 = rotl16 (word0, 1); + + word1 += (word2 & ~word0) + (word3 & word0) + context->S[j + 1]; + word1 = rotl16 (word1, 2); + + word2 += (word3 & ~word1) + (word0 & word1) + context->S[j + 2]; + word2 = rotl16 (word2, 3); + + word3 += (word0 & ~word2) + (word1 & word2) + context->S[j + 3]; + word3 = rotl16 (word3, 5); + + if (i == 4 || i == 10) + { + word0 += context->S[word3 & 63]; + word1 += context->S[word0 & 63]; + word2 += context->S[word1 & 63]; + word3 += context->S[word2 & 63]; + } + } + + outbuf[0] = word0 & 255; + outbuf[1] = word0 >> 8; + outbuf[2] = word1 & 255; + outbuf[3] = word1 >> 8; + outbuf[4] = word2 & 255; + outbuf[5] = word2 >> 8; + outbuf[6] = word3 & 255; + outbuf[7] = word3 >> 8; + } +} + +void +arctwo_decrypt (arctwo_context *context, const char *inbuf, + char *outbuf, size_t length) +{ + for (; length >= ARCTWO_BLOCK_SIZE; length -= ARCTWO_BLOCK_SIZE, + inbuf += ARCTWO_BLOCK_SIZE, outbuf += ARCTWO_BLOCK_SIZE) + { + size_t i, j; + uint16_t word0 = 0, word1 = 0, word2 = 0, word3 = 0; + + word0 = (word0 << 8) | to_uchar (inbuf[1]); + word0 = (word0 << 8) | to_uchar (inbuf[0]); + word1 = (word1 << 8) | to_uchar (inbuf[3]); + word1 = (word1 << 8) | to_uchar (inbuf[2]); + word2 = (word2 << 8) | to_uchar (inbuf[5]); + word2 = (word2 << 8) | to_uchar (inbuf[4]); + word3 = (word3 << 8) | to_uchar (inbuf[7]); + word3 = (word3 << 8) | to_uchar (inbuf[6]); + + for (i = 16; i > 0; i--) + { + j = (i - 1) * 4; + + word3 = rotr16 (word3, 5); + word3 -= (word0 & ~word2) + (word1 & word2) + context->S[j + 3]; + + word2 = rotr16 (word2, 3); + word2 -= (word3 & ~word1) + (word0 & word1) + context->S[j + 2]; + + word1 = rotr16 (word1, 2); + word1 -= (word2 & ~word0) + (word3 & word0) + context->S[j + 1]; + + word0 = rotr16 (word0, 1); + word0 -= (word1 & ~word3) + (word2 & word3) + context->S[j]; + + if (i == 6 || i == 12) + { + word3 = word3 - context->S[word2 & 63]; + word2 = word2 - context->S[word1 & 63]; + word1 = word1 - context->S[word0 & 63]; + word0 = word0 - context->S[word3 & 63]; + } + } + + outbuf[0] = word0 & 255; + outbuf[1] = word0 >> 8; + outbuf[2] = word1 & 255; + outbuf[3] = word1 >> 8; + outbuf[4] = word2 & 255; + outbuf[5] = word2 >> 8; + outbuf[6] = word3 & 255; + outbuf[7] = word3 >> 8; + } +} + +void +arctwo_setkey_ekb (arctwo_context *context, + size_t keylen, const char *key, size_t effective_keylen) +{ + size_t i; + uint8_t *S, x; + + if (keylen < 40 / 8 || effective_keylen > 1024) + return; + + S = (uint8_t *) context->S; + + for (i = 0; i < keylen; i++) + S[i] = (uint8_t) key[i]; + + for (i = keylen; i < 128; i++) + S[i] = arctwo_sbox[(S[i - keylen] + S[i - 1]) & 255]; + + S[0] = arctwo_sbox[S[0]]; + + /* Phase 2 - reduce effective key size to "bits". This was not + * discussed in Gutmann's paper. I've copied that from the public + * domain code posted in sci.crypt. */ + if (effective_keylen) + { + size_t len = (effective_keylen + 7) >> 3; + i = 128 - len; + x = arctwo_sbox[S[i] & (255 >> (7 & -effective_keylen))]; + S[i] = x; + + while (i--) + { + x = arctwo_sbox[x ^ S[i + len]]; + S[i] = x; + } + } + + /* Make the expanded key, endian independent. */ + for (i = 0; i < 64; i++) + context->S[i] = ((uint16_t) S[i * 2] | (((uint16_t) S[i * 2 + 1]) << 8)); +} |