/* rfc2268.c - The cipher described in rfc2268; aka Ron's Cipher 2. * Copyright (C) 2003 Nikos Mavroyanopoulos * Copyright (C) 2004 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 */ /* 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 decryption. * * The implementation here is based on Peter Gutmann's RRC.2 paper. */ #include #include #include #include #include "g10lib.h" #include "types.h" #include "cipher.h" #define RFC2268_BLOCKSIZE 8 typedef struct { u16 S[64]; } RFC2268_context; static const unsigned char rfc2268_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) << ((u16)(n))) | ((x) >> (16 - (u16)(n)))) #define rotr16(x,n) (((x) >> ((u16)(n))) | ((x) << (16 - (u16)(n)))) static const char *selftest (void); static void do_encrypt (void *context, unsigned char *outbuf, const unsigned char *inbuf) { RFC2268_context *ctx = context; register int i, j; u16 word0 = 0, word1 = 0, word2 = 0, word3 = 0; word0 = (word0 << 8) | inbuf[1]; word0 = (word0 << 8) | inbuf[0]; word1 = (word1 << 8) | inbuf[3]; word1 = (word1 << 8) | inbuf[2]; word2 = (word2 << 8) | inbuf[5]; word2 = (word2 << 8) | inbuf[4]; word3 = (word3 << 8) | inbuf[7]; word3 = (word3 << 8) | inbuf[6]; for (i = 0; i < 16; i++) { j = i * 4; /* For some reason I cannot combine those steps. */ word0 += (word1 & ~word3) + (word2 & word3) + ctx->S[j]; word0 = rotl16(word0, 1); word1 += (word2 & ~word0) + (word3 & word0) + ctx->S[j + 1]; word1 = rotl16(word1, 2); word2 += (word3 & ~word1) + (word0 & word1) + ctx->S[j + 2]; word2 = rotl16(word2, 3); word3 += (word0 & ~word2) + (word1 & word2) + ctx->S[j + 3]; word3 = rotl16(word3, 5); if (i == 4 || i == 10) { word0 += ctx->S[word3 & 63]; word1 += ctx->S[word0 & 63]; word2 += ctx->S[word1 & 63]; word3 += ctx->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; } static unsigned int encrypt_block (void *context, unsigned char *outbuf, const unsigned char *inbuf) { do_encrypt (context, outbuf, inbuf); return /*burn_stack*/ (4 * sizeof(void *) + sizeof(void *) + sizeof(u32) * 4); } static void do_decrypt (void *context, unsigned char *outbuf, const unsigned char *inbuf) { RFC2268_context *ctx = context; register int i, j; u16 word0 = 0, word1 = 0, word2 = 0, word3 = 0; word0 = (word0 << 8) | inbuf[1]; word0 = (word0 << 8) | inbuf[0]; word1 = (word1 << 8) | inbuf[3]; word1 = (word1 << 8) | inbuf[2]; word2 = (word2 << 8) | inbuf[5]; word2 = (word2 << 8) | inbuf[4]; word3 = (word3 << 8) | inbuf[7]; word3 = (word3 << 8) | inbuf[6]; for (i = 15; i >= 0; i--) { j = i * 4; word3 = rotr16(word3, 5); word3 -= (word0 & ~word2) + (word1 & word2) + ctx->S[j + 3]; word2 = rotr16(word2, 3); word2 -= (word3 & ~word1) + (word0 & word1) + ctx->S[j + 2]; word1 = rotr16(word1, 2); word1 -= (word2 & ~word0) + (word3 & word0) + ctx->S[j + 1]; word0 = rotr16(word0, 1); word0 -= (word1 & ~word3) + (word2 & word3) + ctx->S[j]; if (i == 5 || i == 11) { word3 = word3 - ctx->S[word2 & 63]; word2 = word2 - ctx->S[word1 & 63]; word1 = word1 - ctx->S[word0 & 63]; word0 = word0 - ctx->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; } static unsigned int decrypt_block (void *context, unsigned char *outbuf, const unsigned char *inbuf) { do_decrypt (context, outbuf, inbuf); return /*burn_stack*/ (4 * sizeof(void *) + sizeof(void *) + sizeof(u32) * 4); } static gpg_err_code_t setkey_core (void *context, const unsigned char *key, unsigned int keylen, int with_phase2) { static int initialized; static const char *selftest_failed; RFC2268_context *ctx = context; unsigned int i; unsigned char *S, x; int len; int bits = keylen * 8; if (!initialized) { initialized = 1; selftest_failed = selftest (); if (selftest_failed) log_error ("RFC2268 selftest failed (%s).\n", selftest_failed); } if (selftest_failed) return GPG_ERR_SELFTEST_FAILED; if (keylen < 40 / 8) /* We want at least 40 bits. */ return GPG_ERR_INV_KEYLEN; S = (unsigned char *) ctx->S; for (i = 0; i < keylen; i++) S[i] = key[i]; for (i = keylen; i < 128; i++) S[i] = rfc2268_sbox[(S[i - keylen] + S[i - 1]) & 255]; S[0] = rfc2268_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 (with_phase2) { len = (bits + 7) >> 3; i = 128 - len; x = rfc2268_sbox[S[i] & (255 >> (7 & -bits))]; S[i] = x; while (i--) { x = rfc2268_sbox[x ^ S[i + len]]; S[i] = x; } } /* Make the expanded key, endian independent. */ for (i = 0; i < 64; i++) ctx->S[i] = ( (u16) S[i * 2] | (((u16) S[i * 2 + 1]) << 8)); return 0; } static gpg_err_code_t do_setkey (void *context, const unsigned char *key, unsigned int keylen) { return setkey_core (context, key, keylen, 1); } static const char * selftest (void) { RFC2268_context ctx; unsigned char scratch[16]; /* Test vectors from Peter Gutmann's paper. */ static unsigned char key_1[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; static unsigned char plaintext_1[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; static const unsigned char ciphertext_1[] = { 0x1C, 0x19, 0x8A, 0x83, 0x8D, 0xF0, 0x28, 0xB7 }; static unsigned char key_2[] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; static unsigned char plaintext_2[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; static unsigned char ciphertext_2[] = { 0x50, 0xDC, 0x01, 0x62, 0xBD, 0x75, 0x7F, 0x31 }; /* This one was checked against libmcrypt's RFC2268. */ static unsigned char key_3[] = { 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; static unsigned char plaintext_3[] = { 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; static unsigned char ciphertext_3[] = { 0x8f, 0xd1, 0x03, 0x89, 0x33, 0x6b, 0xf9, 0x5e }; /* First test. */ setkey_core (&ctx, key_1, sizeof(key_1), 0); do_encrypt (&ctx, scratch, plaintext_1); if (memcmp (scratch, ciphertext_1, sizeof(ciphertext_1))) return "RFC2268 encryption test 1 failed."; setkey_core (&ctx, key_1, sizeof(key_1), 0); do_decrypt (&ctx, scratch, scratch); if (memcmp (scratch, plaintext_1, sizeof(plaintext_1))) return "RFC2268 decryption test 1 failed."; /* Second test. */ setkey_core (&ctx, key_2, sizeof(key_2), 0); do_encrypt (&ctx, scratch, plaintext_2); if (memcmp (scratch, ciphertext_2, sizeof(ciphertext_2))) return "RFC2268 encryption test 2 failed."; setkey_core (&ctx, key_2, sizeof(key_2), 0); do_decrypt (&ctx, scratch, scratch); if (memcmp (scratch, plaintext_2, sizeof(plaintext_2))) return "RFC2268 decryption test 2 failed."; /* Third test. */ setkey_core(&ctx, key_3, sizeof(key_3), 0); do_encrypt(&ctx, scratch, plaintext_3); if (memcmp(scratch, ciphertext_3, sizeof(ciphertext_3))) return "RFC2268 encryption test 3 failed."; setkey_core (&ctx, key_3, sizeof(key_3), 0); do_decrypt (&ctx, scratch, scratch); if (memcmp(scratch, plaintext_3, sizeof(plaintext_3))) return "RFC2268 decryption test 3 failed."; return NULL; } static gcry_cipher_oid_spec_t oids_rfc2268_40[] = { /*{ "1.2.840.113549.3.2", GCRY_CIPHER_MODE_CBC },*/ /* pbeWithSHAAnd40BitRC2_CBC */ { "1.2.840.113549.1.12.1.6", GCRY_CIPHER_MODE_CBC }, { NULL } }; static gcry_cipher_oid_spec_t oids_rfc2268_128[] = { /* pbeWithSHAAnd128BitRC2_CBC */ { "1.2.840.113549.1.12.1.5", GCRY_CIPHER_MODE_CBC }, { NULL } }; gcry_cipher_spec_t _gcry_cipher_spec_rfc2268_40 = { GCRY_CIPHER_RFC2268_40, {0, 0}, "RFC2268_40", NULL, oids_rfc2268_40, RFC2268_BLOCKSIZE, 40, sizeof(RFC2268_context), do_setkey, encrypt_block, decrypt_block }; gcry_cipher_spec_t _gcry_cipher_spec_rfc2268_128 = { GCRY_CIPHER_RFC2268_128, {0, 0}, "RFC2268_128", NULL, oids_rfc2268_128, RFC2268_BLOCKSIZE, 128, sizeof(RFC2268_context), do_setkey, encrypt_block, decrypt_block };