diff options
Diffstat (limited to 'libavutil/des.c')
-rw-r--r-- | libavutil/des.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/libavutil/des.c b/libavutil/des.c new file mode 100644 index 0000000..36f90ff --- /dev/null +++ b/libavutil/des.c @@ -0,0 +1,330 @@ +/* + * DES encryption/decryption + * Copyright (c) 2007 Reimar Doeffinger + * + * This file is part of FFmpeg. + * + * FFmpeg 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. + * + * FFmpeg 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 FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ +#include <inttypes.h> +#include "des.h" + +#define T(a, b, c, d, e, f, g, h) 64-a,64-b,64-c,64-d,64-e,64-f,64-g,64-h +static const uint8_t IP_shuffle[] = { + T(58, 50, 42, 34, 26, 18, 10, 2), + T(60, 52, 44, 36, 28, 20, 12, 4), + T(62, 54, 46, 38, 30, 22, 14, 6), + T(64, 56, 48, 40, 32, 24, 16, 8), + T(57, 49, 41, 33, 25, 17, 9, 1), + T(59, 51, 43, 35, 27, 19, 11, 3), + T(61, 53, 45, 37, 29, 21, 13, 5), + T(63, 55, 47, 39, 31, 23, 15, 7) +}; +#undef T + +#define T(a, b, c, d) 32-a,32-b,32-c,32-d +static const uint8_t P_shuffle[] = { + T(16, 7, 20, 21), + T(29, 12, 28, 17), + T( 1, 15, 23, 26), + T( 5, 18, 31, 10), + T( 2, 8, 24, 14), + T(32, 27, 3, 9), + T(19, 13, 30, 6), + T(22, 11, 4, 25) +}; +#undef T + +#define T(a, b, c, d, e, f, g) 64-a,64-b,64-c,64-d,64-e,64-f,64-g +static const uint8_t PC1_shuffle[] = { + T(57, 49, 41, 33, 25, 17, 9), + T( 1, 58, 50, 42, 34, 26, 18), + T(10, 2, 59, 51, 43, 35, 27), + T(19, 11, 3, 60, 52, 44, 36), + T(63, 55, 47, 39, 31, 23, 15), + T( 7, 62, 54, 46, 38, 30, 22), + T(14, 6, 61, 53, 45, 37, 29), + T(21, 13, 5, 28, 20, 12, 4) +}; +#undef T + +#define T(a, b, c, d, e, f) 56-a,56-b,56-c,56-d,56-e,56-f +static const uint8_t PC2_shuffle[] = { + T(14, 17, 11, 24, 1, 5), + T( 3, 28, 15, 6, 21, 10), + T(23, 19, 12, 4, 26, 8), + T(16, 7, 27, 20, 13, 2), + T(41, 52, 31, 37, 47, 55), + T(30, 40, 51, 45, 33, 48), + T(44, 49, 39, 56, 34, 53), + T(46, 42, 50, 36, 29, 32) +}; +#undef T + +#ifdef CONFIG_SMALL +static const uint8_t S_boxes[8][32] = { + { + 0x0e, 0xf4, 0x7d, 0x41, 0xe2, 0x2f, 0xdb, 0x18, 0xa3, 0x6a, 0xc6, 0xbc, 0x95, 0x59, 0x30, 0x87, + 0xf4, 0xc1, 0x8e, 0x28, 0x4d, 0x96, 0x12, 0x7b, 0x5f, 0xbc, 0x39, 0xe7, 0xa3, 0x0a, 0x65, 0xd0, + }, { + 0x3f, 0xd1, 0x48, 0x7e, 0xf6, 0x2b, 0x83, 0xe4, 0xc9, 0x07, 0x12, 0xad, 0x6c, 0x90, 0xb5, 0x5a, + 0xd0, 0x8e, 0xa7, 0x1b, 0x3a, 0xf4, 0x4d, 0x21, 0xb5, 0x68, 0x7c, 0xc6, 0x09, 0x53, 0xe2, 0x9f, + }, { + 0xda, 0x70, 0x09, 0x9e, 0x36, 0x43, 0x6f, 0xa5, 0x21, 0x8d, 0x5c, 0xe7, 0xcb, 0xb4, 0xf2, 0x18, + 0x1d, 0xa6, 0xd4, 0x09, 0x68, 0x9f, 0x83, 0x70, 0x4b, 0xf1, 0xe2, 0x3c, 0xb5, 0x5a, 0x2e, 0xc7, + }, { + 0xd7, 0x8d, 0xbe, 0x53, 0x60, 0xf6, 0x09, 0x3a, 0x41, 0x72, 0x28, 0xc5, 0x1b, 0xac, 0xe4, 0x9f, + 0x3a, 0xf6, 0x09, 0x60, 0xac, 0x1b, 0xd7, 0x8d, 0x9f, 0x41, 0x53, 0xbe, 0xc5, 0x72, 0x28, 0xe4, + }, { + 0xe2, 0xbc, 0x24, 0xc1, 0x47, 0x7a, 0xdb, 0x16, 0x58, 0x05, 0xf3, 0xaf, 0x3d, 0x90, 0x8e, 0x69, + 0xb4, 0x82, 0xc1, 0x7b, 0x1a, 0xed, 0x27, 0xd8, 0x6f, 0xf9, 0x0c, 0x95, 0xa6, 0x43, 0x50, 0x3e, + }, { + 0xac, 0xf1, 0x4a, 0x2f, 0x79, 0xc2, 0x96, 0x58, 0x60, 0x1d, 0xd3, 0xe4, 0x0e, 0xb7, 0x35, 0x8b, + 0x49, 0x3e, 0x2f, 0xc5, 0x92, 0x58, 0xfc, 0xa3, 0xb7, 0xe0, 0x14, 0x7a, 0x61, 0x0d, 0x8b, 0xd6, + }, { + 0xd4, 0x0b, 0xb2, 0x7e, 0x4f, 0x90, 0x18, 0xad, 0xe3, 0x3c, 0x59, 0xc7, 0x25, 0xfa, 0x86, 0x61, + 0x61, 0xb4, 0xdb, 0x8d, 0x1c, 0x43, 0xa7, 0x7e, 0x9a, 0x5f, 0x06, 0xf8, 0xe0, 0x25, 0x39, 0xc2, + }, { + 0x1d, 0xf2, 0xd8, 0x84, 0xa6, 0x3f, 0x7b, 0x41, 0xca, 0x59, 0x63, 0xbe, 0x05, 0xe0, 0x9c, 0x27, + 0x27, 0x1b, 0xe4, 0x71, 0x49, 0xac, 0x8e, 0xd2, 0xf0, 0xc6, 0x9a, 0x0d, 0x3f, 0x53, 0x65, 0xb8, + } +}; +#else +/** + * This table contains the results of applying both the S-box and P-shuffle. + * It can be regenerated by compiling this file with -DCONFIG_SMALL -DTEST -DGENTABLES + */ +static const uint32_t S_boxes_P_shuffle[8][64] = { + { + 0x00808200, 0x00000000, 0x00008000, 0x00808202, 0x00808002, 0x00008202, 0x00000002, 0x00008000, + 0x00000200, 0x00808200, 0x00808202, 0x00000200, 0x00800202, 0x00808002, 0x00800000, 0x00000002, + 0x00000202, 0x00800200, 0x00800200, 0x00008200, 0x00008200, 0x00808000, 0x00808000, 0x00800202, + 0x00008002, 0x00800002, 0x00800002, 0x00008002, 0x00000000, 0x00000202, 0x00008202, 0x00800000, + 0x00008000, 0x00808202, 0x00000002, 0x00808000, 0x00808200, 0x00800000, 0x00800000, 0x00000200, + 0x00808002, 0x00008000, 0x00008200, 0x00800002, 0x00000200, 0x00000002, 0x00800202, 0x00008202, + 0x00808202, 0x00008002, 0x00808000, 0x00800202, 0x00800002, 0x00000202, 0x00008202, 0x00808200, + 0x00000202, 0x00800200, 0x00800200, 0x00000000, 0x00008002, 0x00008200, 0x00000000, 0x00808002, + }, + { + 0x40084010, 0x40004000, 0x00004000, 0x00084010, 0x00080000, 0x00000010, 0x40080010, 0x40004010, + 0x40000010, 0x40084010, 0x40084000, 0x40000000, 0x40004000, 0x00080000, 0x00000010, 0x40080010, + 0x00084000, 0x00080010, 0x40004010, 0x00000000, 0x40000000, 0x00004000, 0x00084010, 0x40080000, + 0x00080010, 0x40000010, 0x00000000, 0x00084000, 0x00004010, 0x40084000, 0x40080000, 0x00004010, + 0x00000000, 0x00084010, 0x40080010, 0x00080000, 0x40004010, 0x40080000, 0x40084000, 0x00004000, + 0x40080000, 0x40004000, 0x00000010, 0x40084010, 0x00084010, 0x00000010, 0x00004000, 0x40000000, + 0x00004010, 0x40084000, 0x00080000, 0x40000010, 0x00080010, 0x40004010, 0x40000010, 0x00080010, + 0x00084000, 0x00000000, 0x40004000, 0x00004010, 0x40000000, 0x40080010, 0x40084010, 0x00084000, + }, + { + 0x00000104, 0x04010100, 0x00000000, 0x04010004, 0x04000100, 0x00000000, 0x00010104, 0x04000100, + 0x00010004, 0x04000004, 0x04000004, 0x00010000, 0x04010104, 0x00010004, 0x04010000, 0x00000104, + 0x04000000, 0x00000004, 0x04010100, 0x00000100, 0x00010100, 0x04010000, 0x04010004, 0x00010104, + 0x04000104, 0x00010100, 0x00010000, 0x04000104, 0x00000004, 0x04010104, 0x00000100, 0x04000000, + 0x04010100, 0x04000000, 0x00010004, 0x00000104, 0x00010000, 0x04010100, 0x04000100, 0x00000000, + 0x00000100, 0x00010004, 0x04010104, 0x04000100, 0x04000004, 0x00000100, 0x00000000, 0x04010004, + 0x04000104, 0x00010000, 0x04000000, 0x04010104, 0x00000004, 0x00010104, 0x00010100, 0x04000004, + 0x04010000, 0x04000104, 0x00000104, 0x04010000, 0x00010104, 0x00000004, 0x04010004, 0x00010100, + }, + { + 0x80401000, 0x80001040, 0x80001040, 0x00000040, 0x00401040, 0x80400040, 0x80400000, 0x80001000, + 0x00000000, 0x00401000, 0x00401000, 0x80401040, 0x80000040, 0x00000000, 0x00400040, 0x80400000, + 0x80000000, 0x00001000, 0x00400000, 0x80401000, 0x00000040, 0x00400000, 0x80001000, 0x00001040, + 0x80400040, 0x80000000, 0x00001040, 0x00400040, 0x00001000, 0x00401040, 0x80401040, 0x80000040, + 0x00400040, 0x80400000, 0x00401000, 0x80401040, 0x80000040, 0x00000000, 0x00000000, 0x00401000, + 0x00001040, 0x00400040, 0x80400040, 0x80000000, 0x80401000, 0x80001040, 0x80001040, 0x00000040, + 0x80401040, 0x80000040, 0x80000000, 0x00001000, 0x80400000, 0x80001000, 0x00401040, 0x80400040, + 0x80001000, 0x00001040, 0x00400000, 0x80401000, 0x00000040, 0x00400000, 0x00001000, 0x00401040, + }, + { + 0x00000080, 0x01040080, 0x01040000, 0x21000080, 0x00040000, 0x00000080, 0x20000000, 0x01040000, + 0x20040080, 0x00040000, 0x01000080, 0x20040080, 0x21000080, 0x21040000, 0x00040080, 0x20000000, + 0x01000000, 0x20040000, 0x20040000, 0x00000000, 0x20000080, 0x21040080, 0x21040080, 0x01000080, + 0x21040000, 0x20000080, 0x00000000, 0x21000000, 0x01040080, 0x01000000, 0x21000000, 0x00040080, + 0x00040000, 0x21000080, 0x00000080, 0x01000000, 0x20000000, 0x01040000, 0x21000080, 0x20040080, + 0x01000080, 0x20000000, 0x21040000, 0x01040080, 0x20040080, 0x00000080, 0x01000000, 0x21040000, + 0x21040080, 0x00040080, 0x21000000, 0x21040080, 0x01040000, 0x00000000, 0x20040000, 0x21000000, + 0x00040080, 0x01000080, 0x20000080, 0x00040000, 0x00000000, 0x20040000, 0x01040080, 0x20000080, + }, + { + 0x10000008, 0x10200000, 0x00002000, 0x10202008, 0x10200000, 0x00000008, 0x10202008, 0x00200000, + 0x10002000, 0x00202008, 0x00200000, 0x10000008, 0x00200008, 0x10002000, 0x10000000, 0x00002008, + 0x00000000, 0x00200008, 0x10002008, 0x00002000, 0x00202000, 0x10002008, 0x00000008, 0x10200008, + 0x10200008, 0x00000000, 0x00202008, 0x10202000, 0x00002008, 0x00202000, 0x10202000, 0x10000000, + 0x10002000, 0x00000008, 0x10200008, 0x00202000, 0x10202008, 0x00200000, 0x00002008, 0x10000008, + 0x00200000, 0x10002000, 0x10000000, 0x00002008, 0x10000008, 0x10202008, 0x00202000, 0x10200000, + 0x00202008, 0x10202000, 0x00000000, 0x10200008, 0x00000008, 0x00002000, 0x10200000, 0x00202008, + 0x00002000, 0x00200008, 0x10002008, 0x00000000, 0x10202000, 0x10000000, 0x00200008, 0x10002008, + }, + { + 0x00100000, 0x02100001, 0x02000401, 0x00000000, 0x00000400, 0x02000401, 0x00100401, 0x02100400, + 0x02100401, 0x00100000, 0x00000000, 0x02000001, 0x00000001, 0x02000000, 0x02100001, 0x00000401, + 0x02000400, 0x00100401, 0x00100001, 0x02000400, 0x02000001, 0x02100000, 0x02100400, 0x00100001, + 0x02100000, 0x00000400, 0x00000401, 0x02100401, 0x00100400, 0x00000001, 0x02000000, 0x00100400, + 0x02000000, 0x00100400, 0x00100000, 0x02000401, 0x02000401, 0x02100001, 0x02100001, 0x00000001, + 0x00100001, 0x02000000, 0x02000400, 0x00100000, 0x02100400, 0x00000401, 0x00100401, 0x02100400, + 0x00000401, 0x02000001, 0x02100401, 0x02100000, 0x00100400, 0x00000000, 0x00000001, 0x02100401, + 0x00000000, 0x00100401, 0x02100000, 0x00000400, 0x02000001, 0x02000400, 0x00000400, 0x00100001, + }, + { + 0x08000820, 0x00000800, 0x00020000, 0x08020820, 0x08000000, 0x08000820, 0x00000020, 0x08000000, + 0x00020020, 0x08020000, 0x08020820, 0x00020800, 0x08020800, 0x00020820, 0x00000800, 0x00000020, + 0x08020000, 0x08000020, 0x08000800, 0x00000820, 0x00020800, 0x00020020, 0x08020020, 0x08020800, + 0x00000820, 0x00000000, 0x00000000, 0x08020020, 0x08000020, 0x08000800, 0x00020820, 0x00020000, + 0x00020820, 0x00020000, 0x08020800, 0x00000800, 0x00000020, 0x08020020, 0x00000800, 0x00020820, + 0x08000800, 0x00000020, 0x08000020, 0x08020000, 0x08020020, 0x08000000, 0x00020000, 0x08000820, + 0x00000000, 0x08020820, 0x00020020, 0x08000020, 0x08020000, 0x08000800, 0x08000820, 0x00000000, + 0x08020820, 0x00020800, 0x00020800, 0x00000820, 0x00000820, 0x00020020, 0x08000000, 0x08020800, + }, +}; +#endif + +static uint64_t shuffle(uint64_t in, const uint8_t *shuffle, int shuffle_len) { + int i; + uint64_t res = 0; + for (i = 0; i < shuffle_len; i++) + res += res + ((in >> *shuffle++) & 1); + return res; +} + +static uint64_t shuffle_inv(uint64_t in, const uint8_t *shuffle, int shuffle_len) { + int i; + uint64_t res = 0; + shuffle += shuffle_len - 1; + for (i = 0; i < shuffle_len; i++) { + res |= (in & 1) << *shuffle--; + in >>= 1; + } + return res; +} + +static uint32_t f_func(uint32_t r, uint64_t k) { + int i; + uint32_t out = 0; + // rotate to get first part of E-shuffle in the lowest 6 bits + r = (r << 1) | (r >> 31); + // apply S-boxes, those compress the data again from 8 * 6 to 8 * 4 bits + for (i = 7; i >= 0; i--) { + uint8_t tmp = (r ^ k) & 0x3f; +#ifdef CONFIG_SMALL + uint8_t v = S_boxes[i][tmp >> 1]; + if (tmp & 1) v >>= 4; + out = (out >> 4) | (v << 28); +#else + out |= S_boxes_P_shuffle[i][tmp]; +#endif + // get next 6 bits of E-shuffle and round key k into the lowest bits + r = (r >> 4) | (r << 28); + k >>= 6; + } +#ifdef CONFIG_SMALL + out = shuffle(out, P_shuffle, sizeof(P_shuffle)); +#endif + return out; +} + +/** + * \brief rotate the two halves of the expanded 56 bit key each 1 bit left + * + * Note: the specification calls this "shift", so I kept it although + * it is confusing. + */ +static uint64_t key_shift_left(uint64_t CDn) { + uint64_t carries = (CDn >> 27) & 0x10000001; + CDn <<= 1; + CDn &= ~0x10000001; + CDn |= carries; + return CDn; +} + +uint64_t ff_des_encdec(uint64_t in, uint64_t key, int decrypt) { + int i; + uint64_t K[16]; + // discard parity bits from key and shuffle it into C and D parts + uint64_t CDn = shuffle(key, PC1_shuffle, sizeof(PC1_shuffle)); + // generate round keys + for (i = 0; i < 16; i++) { + CDn = key_shift_left(CDn); + if (i > 1 && i != 8 && i != 15) + CDn = key_shift_left(CDn); + K[i] = shuffle(CDn, PC2_shuffle, sizeof(PC2_shuffle)); + } + // used to apply round keys in reverse order for decryption + decrypt = decrypt ? 15 : 0; + // shuffle irrelevant to security but to ease hardware implementations + in = shuffle(in, IP_shuffle, sizeof(IP_shuffle)); + for (i = 0; i < 16; i++) { + uint32_t f_res; + f_res = f_func(in, K[decrypt ^ i]); + in = (in << 32) | (in >> 32); + in ^= f_res; + } + in = (in << 32) | (in >> 32); + // reverse shuffle used to ease hardware implementations + in = shuffle_inv(in, IP_shuffle, sizeof(IP_shuffle)); + return in; +} + +#ifdef TEST +#include <stdlib.h> +#include <stdio.h> +#include <sys/time.h> +static uint64_t rand64(void) { + uint64_t r = rand(); + r = (r << 32) | rand(); + return r; +} + +int main(void) { + int i, j; + struct timeval tv; + uint64_t key; + uint64_t data; + uint64_t ct; + gettimeofday(&tv, NULL); + srand(tv.tv_sec * 1000 * 1000 + tv.tv_usec); + key = 0x123456789abcdef0ULL; + data = 0xfedcba9876543210ULL; + if (ff_des_encdec(data, key, 0) != 0x4ab65b3d4b061518ULL) { + printf("Test 1 failed\n"); + return 1; + } + for (i = 0; i < 1000000; i++) { + key = rand64(); + data = rand64(); + ct = ff_des_encdec(data, key, 0); + if (ff_des_encdec(ct, key, 1) != data) { + printf("Test 2 failed\n"); + return 1; + } + } +#ifdef GENTABLES + printf("static const uint32_t S_boxes_P_shuffle[8][64] = {\n"); + for (i = 0; i < 8; i++) { + printf(" {"); + for (j = 0; j < 64; j++) { + uint32_t v = S_boxes[i][j >> 1]; + v = j & 1 ? v >> 4 : v & 0xf; + v <<= 28 - 4 * i; + v = shuffle(v, P_shuffle, sizeof(P_shuffle)); + printf((j & 7) == 0 ? "\n " : " "); + printf("0x%08X,", v); + } + printf("\n },\n"); + } + printf("};\n"); +#endif + return 0; +} +#endif |