libavutil/des.c - third_party/ffmpeg - Git at Google

 /*
  * 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 <stdint.h>

 #include "avutil.h"
 #include "common.h"
 #include "intreadwrite.h"
 #include "mem.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

 #if CONFIG_SMALL || defined(GENTABLES)
 #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
 #endif

 #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

 #if 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 tests/des.c with "-DCONFIG_SMALL -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;
 #if 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;
     }
 #if 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;
 }

 static void gen_roundkeys(uint64_t K[16], uint64_t key)
 {
     int i;
     // 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));
     }
 }

 static uint64_t des_encdec(uint64_t in, uint64_t K[16], int decrypt)
 {
     int i;
     // 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;
 }

 AVDES *av_des_alloc(void)
 {
     return av_mallocz(sizeof(struct AVDES));
 }

 int av_des_init(AVDES *d, const uint8_t *key, int key_bits, av_unused int decrypt) {
     if (key_bits != 64 && key_bits != 192)
         return AVERROR(EINVAL);
     d->triple_des = key_bits > 64;
     gen_roundkeys(d->round_keys[0], AV_RB64(key));
     if (d->triple_des) {
         gen_roundkeys(d->round_keys[1], AV_RB64(key +  8));
         gen_roundkeys(d->round_keys[2], AV_RB64(key + 16));
     }
     return 0;
 }

 static void av_des_crypt_mac(AVDES *d, uint8_t *dst, const uint8_t *src,
                              int count, uint8_t *iv, int decrypt, int mac)
 {
     uint64_t iv_val = iv ? AV_RB64(iv) : 0;
     while (count-- > 0) {
         uint64_t dst_val;
         uint64_t src_val = src ? AV_RB64(src) : 0;
         if (decrypt) {
             uint64_t tmp = src_val;
             if (d->triple_des) {
                 src_val = des_encdec(src_val, d->round_keys[2], 1);
                 src_val = des_encdec(src_val, d->round_keys[1], 0);
             }
             dst_val = des_encdec(src_val, d->round_keys[0], 1) ^ iv_val;
             iv_val  = iv ? tmp : 0;
         } else {
             dst_val = des_encdec(src_val ^ iv_val, d->round_keys[0], 0);
             if (d->triple_des) {
                 dst_val = des_encdec(dst_val, d->round_keys[1], 1);
                 dst_val = des_encdec(dst_val, d->round_keys[2], 0);
             }
             iv_val = iv ? dst_val : 0;
         }
         AV_WB64(dst, dst_val);
         src += 8;
         if (!mac)
             dst += 8;
     }
     if (iv)
         AV_WB64(iv, iv_val);
 }

 void av_des_crypt(AVDES *d, uint8_t *dst, const uint8_t *src,
                   int count, uint8_t *iv, int decrypt)
 {
     av_des_crypt_mac(d, dst, src, count, iv, decrypt, 0);
 }

 void av_des_mac(AVDES *d, uint8_t *dst, const uint8_t *src, int count)
 {
     av_des_crypt_mac(d, dst, src, count, (uint8_t[8]) { 0 }, 0, 1);
 }
	/*
	* 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 <stdint.h>

	#include "avutil.h"
	#include "common.h"
	#include "intreadwrite.h"
	#include "mem.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

	#if CONFIG_SMALL \|\| defined(GENTABLES)
	#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
	#endif

	#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

	#if 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 tests/des.c with "-DCONFIG_SMALL -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;
	#if 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;
	}
	#if 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;
	}

	static void gen_roundkeys(uint64_t K[16], uint64_t key)
	{
	int i;
	// 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));
	}
	}

	static uint64_t des_encdec(uint64_t in, uint64_t K[16], int decrypt)
	{
	int i;
	// 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;
	}

	AVDES *av_des_alloc(void)
	{
	return av_mallocz(sizeof(struct AVDES));
	}

	int av_des_init(AVDES d, const uint8_t key, int key_bits, av_unused int decrypt) {
	if (key_bits != 64 && key_bits != 192)
	return AVERROR(EINVAL);
	d->triple_des = key_bits > 64;
	gen_roundkeys(d->round_keys[0], AV_RB64(key));
	if (d->triple_des) {
	gen_roundkeys(d->round_keys[1], AV_RB64(key + 8));
	gen_roundkeys(d->round_keys[2], AV_RB64(key + 16));
	}
	return 0;
	}

	static void av_des_crypt_mac(AVDES d, uint8_t dst, const uint8_t *src,
	int count, uint8_t *iv, int decrypt, int mac)
	{
	uint64_t iv_val = iv ? AV_RB64(iv) : 0;
	while (count-- > 0) {
	uint64_t dst_val;
	uint64_t src_val = src ? AV_RB64(src) : 0;
	if (decrypt) {
	uint64_t tmp = src_val;
	if (d->triple_des) {
	src_val = des_encdec(src_val, d->round_keys[2], 1);
	src_val = des_encdec(src_val, d->round_keys[1], 0);
	}
	dst_val = des_encdec(src_val, d->round_keys[0], 1) ^ iv_val;
	iv_val = iv ? tmp : 0;
	} else {
	dst_val = des_encdec(src_val ^ iv_val, d->round_keys[0], 0);
	if (d->triple_des) {
	dst_val = des_encdec(dst_val, d->round_keys[1], 1);
	dst_val = des_encdec(dst_val, d->round_keys[2], 0);
	}
	iv_val = iv ? dst_val : 0;
	}
	AV_WB64(dst, dst_val);
	src += 8;
	if (!mac)
	dst += 8;
	}
	if (iv)
	AV_WB64(iv, iv_val);
	}

	void av_des_crypt(AVDES d, uint8_t dst, const uint8_t *src,
	int count, uint8_t *iv, int decrypt)
	{
	av_des_crypt_mac(d, dst, src, count, iv, decrypt, 0);
	}

	void av_des_mac(AVDES d, uint8_t dst, const uint8_t *src, int count)
	{
	av_des_crypt_mac(d, dst, src, count, (uint8_t[8]) { 0 }, 0, 1);
	}