lib/silccrypt/cast.c

   1 /* Modified for SILC. -Pekka */
   2
   3 /* This is an independent implementation of the encryption algorithm:   */
   4 /*                                                                      */
   5 /*         CAST-256 by Carlisle Adams of Entrust Tecnhologies           */
   6 /*                                                                      */
   7 /* which is a candidate algorithm in the Advanced Encryption Standard   */
   8 /* programme of the US National Institute of Standards and Technology.  */
   9 /*                                                                      */
  10 /* Copyright in this implementation is held by Dr B R Gladman but I     */
  11 /* hereby give permission for its free direct or derivative use subject */
  12 /* to acknowledgment of its origin and compliance with any conditions   */
  13 /* that the originators of the algorithm place on its exploitation.     */
  14 /*                                                                      */
  15 /* Dr Brian Gladman (gladman@seven77.demon.co.uk) 14th January 1999     */
  16
  17 /* Timing data for CAST-256 (cast.c)
  18
  19 Core timing without I/O endian conversion:
  20
  21 128 bit key:
  22 Key Setup:    4333 cycles
  23 Encrypt:       633 cycles =    40.4 mbits/sec
  24 Decrypt:       634 cycles =    40.4 mbits/sec
  25 Mean:          634 cycles =    40.4 mbits/sec
  26
  27 192 bit key:
  28 Key Setup:    4342 cycles
  29 Encrypt:       633 cycles =    40.4 mbits/sec
  30 Decrypt:       633 cycles =    40.4 mbits/sec
  31 Mean:          633 cycles =    40.4 mbits/sec
  32
  33 256 bit key:
  34 Key Setup:    4325 cycles
  35 Encrypt:       639 cycles =    40.1 mbits/sec
  36 Decrypt:       638 cycles =    40.1 mbits/sec
  37 Mean:          639 cycles =    40.1 mbits/sec
  38
  39 Full timing with I/O endian conversion:
  40
  41 128 bit key:
  42 Key Setup:    4294 cycles
  43 Encrypt:       678 cycles =    37.8 mbits/sec
  44 Decrypt:       669 cycles =    38.3 mbits/sec
  45 Mean:          674 cycles =    38.0 mbits/sec
  46
  47 192 bit key:
  48 Key Setup:    4314 cycles
  49 Encrypt:       678 cycles =    37.8 mbits/sec
  50 Decrypt:       670 cycles =    38.2 mbits/sec
  51 Mean:          674 cycles =    38.0 mbits/sec
  52
  53 256 bit key:
  54 Key Setup:    4313 cycles
  55 Encrypt:       678 cycles =    37.8 mbits/sec
  56 Decrypt:       669 cycles =    38.3 mbits/sec
  57 Mean:          674 cycles =    38.0 mbits/sec
  58
  59 */
  60
  61 #include "silc.h"
  62 #include "cast_internal.h"
  63 #include "cast.h"
  64
  65 #define io_swap
  66
  67 /*
  68  * SILC Crypto API for Cast-256
  69  */
  70
  71 /* Sets the key for the cipher. */
  72
  73 SILC_CIPHER_API_SET_KEY(cast_cbc)
  74 {
  75   SilcUInt32 k[8];
  76
  77   SILC_GET_WORD_KEY(key, k, keylen);
  78   cast_set_key((CastContext *)context, k, keylen);
  79
  80   return TRUE;
  81 }
  82
  83 /* Sets IV for the cipher. */
  84
  85 SILC_CIPHER_API_SET_IV(cast_cbc)
  86 {
  87
  88 }
  89
  90 /* Returns the size of the cipher context. */
  91
  92 SILC_CIPHER_API_CONTEXT_LEN(cast_cbc)
  93 {
  94   return sizeof(CastContext);
  95 }
  96
  97 /* Encrypts with the cipher in CBC mode. Source and destination buffers
  98    maybe one and same. */
  99
 100 SILC_CIPHER_API_ENCRYPT(cast_cbc)
 101 {
 102   SilcUInt32 tiv[4];
 103   int i;
 104
 105   SILC_ASSERT((len & (16 - 1)) == 0);
 106   if (len & (16 - 1))
 107     return FALSE;
 108
 109   SILC_CBC_GET_IV(tiv, iv);
 110
 111   SILC_CBC_ENC_PRE(tiv, src);
 112   cast_encrypt((CastContext *)context, tiv, tiv);
 113   SILC_CBC_ENC_POST(tiv, dst, src);
 114
 115   for (i = 16; i < len; i += 16) {
 116     SILC_CBC_ENC_PRE(tiv, src);
 117     cast_encrypt((CastContext *)context, tiv, tiv);
 118     SILC_CBC_ENC_POST(tiv, dst, src);
 119   }
 120
 121   SILC_CBC_PUT_IV(tiv, iv);
 122
 123   return TRUE;
 124 }
 125
 126 /* Decrypts with the cipher in CBC mode. Source and destination buffers
 127    maybe one and same. */
 128
 129 SILC_CIPHER_API_DECRYPT(cast_cbc)
 130 {
 131   SilcUInt32 tmp[4], tmp2[4], tiv[4];
 132   int i;
 133
 134   if (len & (16 - 1))
 135     return FALSE;
 136
 137   SILC_CBC_GET_IV(tiv, iv);
 138
 139   SILC_CBC_DEC_PRE(tmp, src);
 140   cast_decrypt((CastContext *)context, tmp, tmp2);
 141   SILC_CBC_DEC_POST(tmp2, dst, src, tmp, tiv);
 142
 143   for (i = 16; i < len; i += 16) {
 144     SILC_CBC_DEC_PRE(tmp, src);
 145     cast_decrypt((CastContext *)context, tmp, tmp2);
 146     SILC_CBC_DEC_POST(tmp2, dst, src, tmp, tiv);
 147   }
 148
 149   SILC_CBC_PUT_IV(tiv, iv);
 150
 151   return TRUE;
 152 }
 153
 154 u4byte s_box[4][256] =
 155 { {
 156     0x30fb40d4, 0x9fa0ff0b, 0x6beccd2f, 0x3f258c7a, 0x1e213f2f, 0x9C004dd3,
 157     0x6003e540, 0xcf9fc949, 0xbfd4af27, 0x88bbbdb5, 0xe2034090, 0x98d09675,
 158     0x6e63a0e0, 0x15c361d2, 0xc2e7661d, 0x22d4ff8e, 0x28683b6f, 0xc07fd059,
 159     0xff2379c8, 0x775f50e2, 0x43c340d3, 0xdf2f8656, 0x887ca41a, 0xa2d2bd2d,
 160     0xa1c9e0d6, 0x346c4819, 0x61b76d87, 0x22540f2f, 0x2abe32e1, 0xaa54166b,
 161     0x22568e3a, 0xa2d341d0, 0x66db40c8, 0xa784392f, 0x004dff2f, 0x2db9d2de,
 162     0x97943fac, 0x4a97c1d8, 0x527644b7, 0xb5f437a7, 0xb82cbaef, 0xd751d159,
 163     0x6ff7f0ed, 0x5a097a1f, 0x827b68d0, 0x90ecf52e, 0x22b0c054, 0xbc8e5935,
 164     0x4b6d2f7f, 0x50bb64a2, 0xd2664910, 0xbee5812d, 0xb7332290, 0xe93b159f,
 165     0xb48ee411, 0x4bff345d, 0xfd45c240, 0xad31973f, 0xc4f6d02e, 0x55fc8165,
 166     0xd5b1caad, 0xa1ac2dae, 0xa2d4b76d, 0xc19b0C50, 0x882240f2, 0x0c6e4f38,
 167     0xa4e4bfd7, 0x4f5ba272, 0x564c1d2f, 0xc59c5319, 0xb949e354, 0xb04669fe,
 168     0xb1b6ab8a, 0xc71358dd, 0x6385c545, 0x110f935d, 0x57538ad5, 0x6a390493,
 169     0xe63d37e0, 0x2a54f6b3, 0x3a787d5f, 0x6276a0b5, 0x19a6fcdf, 0x7a42206a,
 170     0x29f9d4d5, 0xf61b1891, 0xbb72275e, 0xaa508167, 0x38901091, 0xc6b505eb,
 171     0x84c7cb8c, 0x2ad75a0f, 0x874a1427, 0xa2d1936b, 0x2ad286af, 0xaa56d291,
 172     0xd7894360, 0x425c750d, 0x93b39e26, 0x187184c9, 0x6c00b32d, 0x73e2bb14,
 173     0xa0bebc3c, 0x54623779, 0x64459eab, 0x3f328b82, 0x7718cf82, 0x59a2cea6,
 174     0x04ee002e, 0x89fe78e6, 0x3fab0950, 0x325ff6C2, 0x81383f05, 0x6963c5c8,
 175     0x76cb5ad6, 0xd49974c9, 0xca180dcf, 0x380782d5, 0xc7fa5cf6, 0x8ac31511,
 176     0x35e79e13, 0x47da91d0, 0xf40f9086, 0xa7e2419e, 0x31366241, 0x051ef495,
 177     0xaa573b04, 0x4a805d8d, 0x548300d0, 0x00322a3c, 0xbf64cddf, 0xba57a68e,
 178     0x75c6372b, 0x50afd341, 0xa7c13275, 0x915a0bf5, 0x6b54bfab, 0x2b0b1426,
 179     0xab4cc9d7, 0x449ccd82, 0xf7fbf265, 0xab85c5f3, 0x1b55db94, 0xaad4e324,
 180     0xcfa4bd3f, 0x2deaa3e2, 0x9e204d02, 0xc8bd25ac, 0xeadf55b3, 0xd5bd9e98,
 181     0xe31231b2, 0x2ad5ad6c, 0x954329de, 0xadbe4528, 0xd8710f69, 0xaa51c90f,
 182     0xaa786bf6, 0x22513f1e, 0xaa51a79b, 0x2ad344cc, 0x7b5a41f0, 0xd37cfbad,
 183     0x1b069505, 0x41ece491, 0xb4c332e6, 0x032268d4, 0xc9600acc, 0xce387e6d,
 184     0xbf6bb16c, 0x6a70fb78, 0x0d03d9c9, 0xd4df39de, 0xe01063da, 0x4736f464,
 185     0x5ad328d8, 0xb347cc96, 0x75bb0fc3, 0x98511bfb, 0x4ffbcc35, 0xb58bcf6a,
 186     0xe11f0abc, 0xbfc5fe4a, 0xa70aec10, 0xac39570a, 0x3f04442f, 0x6188b153,
 187     0xe0397a2e, 0x5727cb79, 0x9ceb418f, 0x1cacd68d, 0x2ad37c96, 0x0175cb9d,
 188     0xc69dff09, 0xc75b65f0, 0xd9db40d8, 0xec0e7779, 0x4744ead4, 0xb11c3274,
 189     0xdd24cb9e, 0x7e1c54bd, 0xf01144f9, 0xd2240eb1, 0x9675b3fd, 0xa3ac3755,
 190     0xd47c27af, 0x51c85f4d, 0x56907596, 0xa5bb15e6, 0x580304f0, 0xca042cf1,
 191     0x011a37ea, 0x8dbfaadb, 0x35ba3e4a, 0x3526ffa0, 0xc37b4d09, 0xbc306ed9,
 192     0x98a52666, 0x5648f725, 0xff5e569d, 0x0ced63d0, 0x7c63b2cf, 0x700b45e1,
 193     0xd5ea50f1, 0x85a92872, 0xaf1fbda7, 0xd4234870, 0xa7870bf3, 0x2d3b4d79,
 194     0x42e04198, 0x0cd0ede7, 0x26470db8, 0xf881814C, 0x474d6ad7, 0x7c0c5e5c,
 195     0xd1231959, 0x381b7298, 0xf5d2f4db, 0xab838653, 0x6e2f1e23, 0x83719c9e,
 196     0xbd91e046, 0x9a56456e, 0xdc39200c, 0x20c8c571, 0x962bda1c, 0xe1e696ff,
 197     0xb141ab08, 0x7cca89b9, 0x1a69e783, 0x02cc4843, 0xa2f7c579, 0x429ef47d,
 198     0x427b169c, 0x5ac9f049, 0xdd8f0f00, 0x5c8165bf
 199   },
 200   {
 201     0x1f201094, 0xef0ba75b, 0x69e3cf7e, 0x393f4380, 0xfe61cf7a, 0xeec5207a,
 202     0x55889c94, 0x72fc0651, 0xada7ef79, 0x4e1d7235, 0xd55a63ce, 0xde0436ba,
 203     0x99c430ef, 0x5f0c0794, 0x18dcdb7d, 0xa1d6eff3, 0xa0b52f7b, 0x59e83605,
 204     0xee15b094, 0xe9ffd909, 0xdc440086, 0xef944459, 0xba83ccb3, 0xe0c3cdfb,
 205     0xd1da4181, 0x3b092ab1, 0xf997f1c1, 0xa5e6cf7b, 0x01420ddb, 0xe4e7ef5b,
 206     0x25a1ff41, 0xe180f806, 0x1fc41080, 0x179bee7a, 0xd37ac6a9, 0xfe5830a4,
 207     0x98de8b7f, 0x77e83f4e, 0x79929269, 0x24fa9f7b, 0xe113c85b, 0xacc40083,
 208     0xd7503525, 0xf7ea615f, 0x62143154, 0x0d554b63, 0x5d681121, 0xc866c359,
 209     0x3d63cf73, 0xcee234c0, 0xd4d87e87, 0x5c672b21, 0x071f6181, 0x39f7627f,
 210     0x361e3084, 0xe4eb573b, 0x602f64a4, 0xd63acd9c, 0x1bbc4635, 0x9e81032d,
 211     0x2701f50c, 0x99847ab4, 0xa0e3df79, 0xba6cf38c, 0x10843094, 0x2537a95e,
 212     0xf46f6ffe, 0xa1ff3b1f, 0x208cfb6a, 0x8f458c74, 0xd9e0a227, 0x4ec73a34,
 213     0xfc884f69, 0x3e4de8df, 0xef0e0088, 0x3559648d, 0x8a45388c, 0x1d804366,
 214     0x721d9bfd, 0xa58684bb, 0xe8256333, 0x844e8212, 0x128d8098, 0xfed33fb4,
 215     0xce280ae1, 0x27e19ba5, 0xd5a6c252, 0xe49754bd, 0xc5d655dd, 0xeb667064,
 216     0x77840b4d, 0xa1b6a801, 0x84db26a9, 0xe0b56714, 0x21f043b7, 0xe5d05860,
 217     0x54f03084, 0x066ff472, 0xa31aa153, 0xdadc4755, 0xb5625dbf, 0x68561be6,
 218     0x83ca6b94, 0x2d6ed23b, 0xeccf01db, 0xa6d3d0ba, 0xb6803d5c, 0xaf77a709,
 219     0x33b4a34c, 0x397bc8d6, 0x5ee22b95, 0x5f0e5304, 0x81ed6f61, 0x20e74364,
 220     0xb45e1378, 0xde18639b, 0x881ca122, 0xb96726d1, 0x8049a7e8, 0x22b7da7b,
 221     0x5e552d25, 0x5272d237, 0x79d2951c, 0xc60d894c, 0x488cb402, 0x1ba4fe5b,
 222     0xa4b09f6b, 0x1ca815cf, 0xa20c3005, 0x8871df63, 0xb9de2fcb, 0x0cc6c9e9,
 223     0x0beeff53, 0xe3214517, 0xb4542835, 0x9f63293c, 0xee41e729, 0x6e1d2d7c,
 224     0x50045286, 0x1e6685f3, 0xf33401c6, 0x30a22c95, 0x31a70850, 0x60930f13,
 225     0x73f98417, 0xa1269859, 0xec645c44, 0x52c877a9, 0xcdff33a6, 0xa02b1741,
 226     0x7cbad9a2, 0x2180036f, 0x50d99c08, 0xcb3f4861, 0xc26bd765, 0x64a3f6ab,
 227     0x80342676, 0x25a75e7b, 0xe4e6d1fc, 0x20c710e6, 0xcdf0b680, 0x17844d3b,
 228     0x31eef84d, 0x7e0824e4, 0x2ccb49eb, 0x846a3bae, 0x8ff77888, 0xee5d60f6,
 229     0x7af75673, 0x2fdd5cdb, 0xa11631c1, 0x30f66f43, 0xb3faec54, 0x157fd7fa,
 230     0xef8579cc, 0xd152de58, 0xdb2ffd5e, 0x8f32ce19, 0x306af97a, 0x02f03ef8,
 231     0x99319ad5, 0xc242fa0f, 0xa7e3ebb0, 0xc68e4906, 0xb8da230c, 0x80823028,
 232     0xdcdef3c8, 0xd35fb171, 0x088a1bc8, 0xbec0c560, 0x61a3c9e8, 0xbca8f54d,
 233     0xc72feffa, 0x22822e99, 0x82c570b4, 0xd8d94e89, 0x8b1c34bc, 0x301e16e6,
 234     0x273be979, 0xb0ffeaa6, 0x61d9b8c6, 0x00b24869, 0xb7ffce3f, 0x08dc283b,
 235     0x43daf65a, 0xf7e19798, 0x7619b72f, 0x8f1c9ba4, 0xdc8637a0, 0x16a7d3b1,
 236     0x9fc393b7, 0xa7136eeb, 0xc6bcc63e, 0x1a513742, 0xef6828bc, 0x520365d6,
 237     0x2d6a77ab, 0x3527ed4b, 0x821fd216, 0x095c6e2e, 0xdb92f2fb, 0x5eea29cb,
 238     0x145892f5, 0x91584f7f, 0x5483697b, 0x2667a8cc, 0x85196048, 0x8c4bacea,
 239     0x833860d4, 0x0d23e0f9, 0x6c387e8a, 0x0ae6d249, 0xb284600c, 0xd835731d,
 240     0xdcb1c647, 0xac4c56ea, 0x3ebd81b3, 0x230eabb0, 0x6438bc87, 0xf0b5b1fa,
 241     0x8f5ea2b3, 0xfc184642, 0x0a036b7a, 0x4fb089bd, 0x649da589, 0xa345415e,
 242     0x5c038323, 0x3e5d3bb9, 0x43d79572, 0x7e6dd07c, 0x06dfdf1e, 0x6c6cc4ef,
 243     0x7160a539, 0x73bfbe70, 0x83877605, 0x4523ecf1
 244   },
 245   {
 246     0x8defc240, 0x25fa5d9f, 0xeb903dbf, 0xe810c907, 0x47607fff, 0x369fe44b,
 247     0x8c1fc644, 0xaececa90, 0xbeb1f9bf, 0xeefbcaea, 0xe8cf1950, 0x51df07ae,
 248     0x920e8806, 0xf0ad0548, 0xe13c8d83, 0x927010d5, 0x11107d9f, 0x07647db9,
 249     0xb2e3e4d4, 0x3d4f285e, 0xb9afa820, 0xfade82e0, 0xa067268b, 0x8272792e,
 250     0x553fb2c0, 0x489ae22b, 0xd4ef9794, 0x125e3fbc, 0x21fffcee, 0x825b1bfd,
 251     0x9255c5ed, 0x1257a240, 0x4e1a8302, 0xbae07fff, 0x528246e7, 0x8e57140e,
 252     0x3373f7bf, 0x8c9f8188, 0xa6fc4ee8, 0xc982b5a5, 0xa8c01db7, 0x579fc264,
 253     0x67094f31, 0xf2bd3f5f, 0x40fff7c1, 0x1fb78dfc, 0x8e6bd2c1, 0x437be59b,
 254     0x99b03dbf, 0xb5dbc64b, 0x638dc0e6, 0x55819d99, 0xa197c81c, 0x4a012d6e,
 255     0xc5884a28, 0xccc36f71, 0xb843c213, 0x6c0743f1, 0x8309893c, 0x0feddd5f,
 256     0x2f7fe850, 0xd7c07f7e, 0x02507fbf, 0x5afb9a04, 0xa747d2d0, 0x1651192e,
 257     0xaf70bf3e, 0x58c31380, 0x5f98302e, 0x727cc3c4, 0x0a0fb402, 0x0f7fef82,
 258     0x8c96fdad, 0x5d2c2aae, 0x8ee99a49, 0x50da88b8, 0x8427f4a0, 0x1eac5790,
 259     0x796fb449, 0x8252dc15, 0xefbd7d9b, 0xa672597d, 0xada840d8, 0x45f54504,
 260     0xfa5d7403, 0xe83ec305, 0x4f91751a, 0x925669c2, 0x23efe941, 0xa903f12e,
 261     0x60270df2, 0x0276e4b6, 0x94fd6574, 0x927985b2, 0x8276dbcb, 0x02778176,
 262     0xf8af918d, 0x4e48f79e, 0x8f616ddf, 0xe29d840e, 0x842f7d83, 0x340ce5c8,
 263     0x96bbb682, 0x93b4b148, 0xef303cab, 0x984faf28, 0x779faf9b, 0x92dc560d,
 264     0x224d1e20, 0x8437aa88, 0x7d29dc96, 0x2756d3dc, 0x8b907cee, 0xb51fd240,
 265     0xe7c07ce3, 0xe566b4a1, 0xc3e9615e, 0x3cf8209d, 0x6094d1e3, 0xcd9ca341,
 266     0x5c76460e, 0x00ea983b, 0xd4d67881, 0xfd47572c, 0xf76cedd9, 0xbda8229c,
 267     0x127dadaa, 0x438a074e, 0x1f97c090, 0x081bdb8a, 0x93a07ebe, 0xb938ca15,
 268     0x97b03cff, 0x3dc2c0f8, 0x8d1ab2ec, 0x64380e51, 0x68cc7bfb, 0xd90f2788,
 269     0x12490181, 0x5de5ffd4, 0xdd7ef86a, 0x76a2e214, 0xb9a40368, 0x925d958f,
 270     0x4b39fffa, 0xba39aee9, 0xa4ffd30b, 0xfaf7933b, 0x6d498623, 0x193cbcfa,
 271     0x27627545, 0x825cf47a, 0x61bd8ba0, 0xd11e42d1, 0xcead04f4, 0x127ea392,
 272     0x10428db7, 0x8272a972, 0x9270c4a8, 0x127de50b, 0x285ba1c8, 0x3c62f44f,
 273     0x35c0eaa5, 0xe805d231, 0x428929fb, 0xb4fcdf82, 0x4fb66a53, 0x0e7dc15b,
 274     0x1f081fab, 0x108618ae, 0xfcfd086d, 0xf9ff2889, 0x694bcc11, 0x236a5cae,
 275     0x12deca4d, 0x2c3f8cc5, 0xd2d02dfe, 0xf8ef5896, 0xe4cf52da, 0x95155b67,
 276     0x494a488c, 0xb9b6a80c, 0x5c8f82bc, 0x89d36b45, 0x3a609437, 0xec00c9a9,
 277     0x44715253, 0x0a874b49, 0xd773bc40, 0x7c34671c, 0x02717ef6, 0x4feb5536,
 278     0xa2d02fff, 0xd2bf60c4, 0xd43f03c0, 0x50b4ef6d, 0x07478cd1, 0x006e1888,
 279     0xa2e53f55, 0xb9e6d4bc, 0xa2048016, 0x97573833, 0xd7207d67, 0xde0f8f3d,
 280     0x72f87b33, 0xabcc4f33, 0x7688c55d, 0x7b00a6b0, 0x947b0001, 0x570075d2,
 281     0xf9bb88f8, 0x8942019e, 0x4264a5ff, 0x856302e0, 0x72dbd92b, 0xee971b69,
 282     0x6ea22fde, 0x5f08ae2b, 0xaf7a616d, 0xe5c98767, 0xcf1febd2, 0x61efc8c2,
 283     0xf1ac2571, 0xcc8239c2, 0x67214cb8, 0xb1e583d1, 0xb7dc3e62, 0x7f10bdce,
 284     0xf90a5c38, 0x0ff0443d, 0x606e6dc6, 0x60543a49, 0x5727c148, 0x2be98a1d,
 285     0x8ab41738, 0x20e1be24, 0xaf96da0f, 0x68458425, 0x99833be5, 0x600d457d,
 286     0x282f9350, 0x8334b362, 0xd91d1120, 0x2b6d8da0, 0x642b1e31, 0x9c305a00,
 287     0x52bce688, 0x1b03588a, 0xf7baefd5, 0x4142ed9c, 0xa4315c11, 0x83323ec5,
 288     0xdfef4636, 0xa133c501, 0xe9d3531c, 0xee353783
 289   },
 290   {
 291     0x9db30420, 0x1fb6e9de, 0xa7be7bef, 0xd273a298, 0x4a4f7bdb, 0x64ad8c57,
 292     0x85510443, 0xfa020ed1, 0x7e287aff, 0xe60fb663, 0x095f35a1, 0x79ebf120,
 293     0xfd059d43, 0x6497b7b1, 0xf3641f63, 0x241e4adf, 0x28147f5f, 0x4fa2b8cd,
 294     0xc9430040, 0x0cc32220, 0xfdd30b30, 0xc0a5374f, 0x1d2d00d9, 0x24147b15,
 295     0xee4d111a, 0x0fca5167, 0x71ff904c, 0x2d195ffe, 0x1a05645f, 0x0c13fefe,
 296     0x081b08ca, 0x05170121, 0x80530100, 0xe83e5efe, 0xac9af4f8, 0x7fe72701,
 297     0xd2b8ee5f, 0x06df4261, 0xbb9e9b8a, 0x7293ea25, 0xce84ffdf, 0xf5718801,
 298     0x3dd64b04, 0xa26f263b, 0x7ed48400, 0x547eebe6, 0x446d4ca0, 0x6cf3d6f5,
 299     0x2649abdf, 0xaea0c7f5, 0x36338cc1, 0x503f7e93, 0xd3772061, 0x11b638e1,
 300     0x72500e03, 0xf80eb2bb, 0xabe0502e, 0xec8d77de, 0x57971e81, 0xe14f6746,
 301     0xc9335400, 0x6920318f, 0x081dbb99, 0xffc304a5, 0x4d351805, 0x7f3d5ce3,
 302     0xa6c866c6, 0x5d5bcca9, 0xdaec6fea, 0x9f926f91, 0x9f46222f, 0x3991467d,
 303     0xa5bf6d8e, 0x1143c44f, 0x43958302, 0xd0214eeb, 0x022083b8, 0x3fb6180c,
 304     0x18f8931e, 0x281658e6, 0x26486e3e, 0x8bd78a70, 0x7477e4c1, 0xb506e07c,
 305     0xf32d0a25, 0x79098b02, 0xe4eabb81, 0x28123b23, 0x69dead38, 0x1574ca16,
 306     0xdf871b62, 0x211c40b7, 0xa51a9ef9, 0x0014377b, 0x041e8ac8, 0x09114003,
 307     0xbd59e4d2, 0xe3d156d5, 0x4fe876d5, 0x2f91a340, 0x557be8de, 0x00eae4a7,
 308     0x0ce5c2ec, 0x4db4bba6, 0xe756bdff, 0xdd3369ac, 0xec17b035, 0x06572327,
 309     0x99afc8b0, 0x56c8c391, 0x6b65811c, 0x5e146119, 0x6e85cb75, 0xbe07c002,
 310     0xc2325577, 0x893ff4ec, 0x5bbfc92d, 0xd0ec3b25, 0xb7801ab7, 0x8d6d3b24,
 311     0x20c763ef, 0xc366a5fc, 0x9c382880, 0x0ace3205, 0xaac9548a, 0xeca1d7c7,
 312     0x041afa32, 0x1d16625a, 0x6701902c, 0x9b757a54, 0x31d477f7, 0x9126b031,
 313     0x36cc6fdb, 0xc70b8b46, 0xd9e66a48, 0x56e55a79, 0x026a4ceb, 0x52437eff,
 314     0x2f8f76b4, 0x0df980a5, 0x8674cde3, 0xedda04eb, 0x17a9be04, 0x2c18f4df,
 315     0xb7747f9d, 0xab2af7b4, 0xefc34d20, 0x2e096b7c, 0x1741a254, 0xe5b6a035,
 316     0x213d42f6, 0x2c1c7c26, 0x61c2f50f, 0x6552daf9, 0xd2c231f8, 0x25130f69,
 317     0xd8167fa2, 0x0418f2c8, 0x001a96a6, 0x0d1526ab, 0x63315c21, 0x5e0a72ec,
 318     0x49bafefd, 0x187908d9, 0x8d0dbd86, 0x311170a7, 0x3e9b640c, 0xcc3e10d7,
 319     0xd5cad3b6, 0x0caec388, 0xf73001e1, 0x6c728aff, 0x71eae2a1, 0x1f9af36e,
 320     0xcfcbd12f, 0xc1de8417, 0xac07be6b, 0xcb44a1d8, 0x8b9b0f56, 0x013988c3,
 321     0xb1c52fca, 0xb4be31cd, 0xd8782806, 0x12a3a4e2, 0x6f7de532, 0x58fd7eb6,
 322     0xd01ee900, 0x24adffc2, 0xf4990fc5, 0x9711aac5, 0x001d7b95, 0x82e5e7d2,
 323     0x109873f6, 0x00613096, 0xc32d9521, 0xada121ff, 0x29908415, 0x7fbb977f,
 324     0xaf9eb3db, 0x29c9ed2a, 0x5ce2a465, 0xa730f32c, 0xd0aa3fe8, 0x8a5cc091,
 325     0xd49e2ce7, 0x0ce454a9, 0xd60acd86, 0x015f1919, 0x77079103, 0xdea03af6,
 326     0x78a8565e, 0xdee356df, 0x21f05cbe, 0x8b75e387, 0xb3c50651, 0xb8a5c3ef,
 327     0xd8eeb6d2, 0xe523be77, 0xc2154529, 0x2f69efdf, 0xafe67afb, 0xf470c4b2,
 328     0xf3e0eb5b, 0xd6cc9876, 0x39e4460c, 0x1fda8538, 0x1987832f, 0xca007367,
 329     0xa99144f8, 0x296b299e, 0x492fc295, 0x9266beab, 0xb5676e69, 0x9bd3ddda,
 330     0xdf7e052f, 0xdb25701c, 0x1b5e51ee, 0xf65324e6, 0x6afce36c, 0x0316cc04,
 331     0x8644213e, 0xb7dc59d0, 0x7965291f, 0xccd6fd43, 0x41823979, 0x932bcdf6,
 332     0xb657c34d, 0x4edfd282, 0x7ae5290c, 0x3cb9536b, 0x851e20fe, 0x9833557e,
 333     0x13ecf0b0, 0xd3ffb372, 0x3f85c5c1, 0x0aef7ed2
 334   }
 335 };
 336
 337 #define f1(y,x,kr,km)                           \
 338     t  = rotl(km + x, kr);                      \
 339     u  = s_box[0][byte(t,3)];                   \
 340     u ^= s_box[1][byte(t,2)];                   \
 341     u -= s_box[2][byte(t,1)];                   \
 342     u += s_box[3][byte(t,0)];                   \
 343     y ^= u;
 344
 345 #define f2(y,x,kr,km)                           \
 346     t  = rotl(km ^ x, kr);                      \
 347     u  = s_box[0][byte(t,3)];                   \
 348     u -= s_box[1][byte(t,2)];                   \
 349     u += s_box[2][byte(t,1)];                   \
 350     u ^= s_box[3][byte(t,0)];                   \
 351     y ^= u;
 352
 353 #define f3(y,x,kr,km)                           \
 354     t  = rotl(km - x, kr);                      \
 355     u  = s_box[0][byte(t,3)];                   \
 356     u += s_box[1][byte(t,2)];                   \
 357     u ^= s_box[2][byte(t,1)];                   \
 358     u -= s_box[3][byte(t,0)];                   \
 359     y ^= u;
 360
 361 #define f_rnd(x,n)                              \
 362     f1(x[2],x[3],l_key[n],    l_key[n + 4]);    \
 363     f2(x[1],x[2],l_key[n + 1],l_key[n + 5]);    \
 364     f3(x[0],x[1],l_key[n + 2],l_key[n + 6]);    \
 365     f1(x[3],x[0],l_key[n + 3],l_key[n + 7]);
 366
 367 #define i_rnd(x, n)                             \
 368     f1(x[3],x[0],l_key[n + 3],l_key[n + 7]);    \
 369     f3(x[0],x[1],l_key[n + 2],l_key[n + 6]);    \
 370     f2(x[1],x[2],l_key[n + 1],l_key[n + 5]);    \
 371     f1(x[2],x[3],l_key[n],    l_key[n + 4]);
 372
 373 #define k_rnd(k,tr,tm)                          \
 374     f1(k[6],k[7],tr[0],tm[0]);                  \
 375     f2(k[5],k[6],tr[1],tm[1]);                  \
 376     f3(k[4],k[5],tr[2],tm[2]);                  \
 377     f1(k[3],k[4],tr[3],tm[3]);                  \
 378     f2(k[2],k[3],tr[4],tm[4]);                  \
 379     f3(k[1],k[2],tr[5],tm[5]);                  \
 380     f1(k[0],k[1],tr[6],tm[6]);                  \
 381     f2(k[7],k[0],tr[7],tm[7]);
 382
 383 /* initialise the key schedule from the user supplied key   */
 384
 385 u4byte *cast_set_key(CastContext *ctx,
 386                      const u4byte in_key[], const u4byte key_len)
 387 {
 388     u4byte  i, j, t, u, cm, cr, lk[8], tm[8], tr[8];
 389     u4byte *l_key = ctx->l_key;
 390
 391     for(i = 0; i < key_len / 32; ++i)
 392
 393         lk[i] = io_swap(in_key[i]);
 394
 395     for(; i < 8; ++i)
 396
 397         lk[i] = 0;
 398
 399     cm = 0x5a827999; cr = 19;
 400
 401     for(i = 0; i < 96; i += 8)
 402     {
 403         for(j = 0; j < 8; ++j)
 404         {
 405             tm[j] = cm; cm += 0x6ed9eba1;
 406             tr[j] = cr; cr += 17;
 407         }
 408
 409         k_rnd(lk, tr, tm);
 410
 411         for(j = 0; j < 8; ++j)
 412         {
 413             tm[j] = cm; cm += 0x6ed9eba1;
 414             tr[j] = cr; cr += 17;
 415         }
 416
 417         k_rnd(lk, tr, tm);
 418
 419         l_key[i + 0] = lk[0]; l_key[i + 1] = lk[2];
 420         l_key[i + 2] = lk[4]; l_key[i + 3] = lk[6];
 421         l_key[i + 4] = lk[7]; l_key[i + 5] = lk[5];
 422         l_key[i + 6] = lk[3]; l_key[i + 7] = lk[1];
 423     }
 424
 425     return l_key;
 426 }
 427
 428 /* encrypt a block of text  */
 429
 430 void cast_encrypt(CastContext *ctx,
 431                   const u4byte in_blk[4], u4byte out_blk[])
 432 {
 433     u4byte  t, u, blk[4];
 434     u4byte *l_key = ctx->l_key;
 435
 436     blk[0] = io_swap(in_blk[0]); blk[1] = io_swap(in_blk[1]);
 437     blk[2] = io_swap(in_blk[2]); blk[3] = io_swap(in_blk[3]);
 438
 439     f_rnd(blk,  0); f_rnd(blk,  8);
 440     f_rnd(blk, 16); f_rnd(blk, 24);
 441     f_rnd(blk, 32); f_rnd(blk, 40);
 442     i_rnd(blk, 48); i_rnd(blk, 56);
 443     i_rnd(blk, 64); i_rnd(blk, 72);
 444     i_rnd(blk, 80); i_rnd(blk, 88);
 445
 446     out_blk[0] = io_swap(blk[0]); out_blk[1] = io_swap(blk[1]);
 447     out_blk[2] = io_swap(blk[2]); out_blk[3] = io_swap(blk[3]);
 448 }
 449
 450 /* decrypt a block of text  */
 451
 452 void cast_decrypt(CastContext *ctx,
 453                   const u4byte in_blk[4], u4byte out_blk[4])
 454 {
 455     u4byte  t, u, blk[4];
 456     u4byte *l_key = ctx->l_key;
 457
 458     blk[0] = io_swap(in_blk[0]); blk[1] = io_swap(in_blk[1]);
 459     blk[2] = io_swap(in_blk[2]); blk[3] = io_swap(in_blk[3]);
 460
 461     f_rnd(blk, 88); f_rnd(blk, 80);
 462     f_rnd(blk, 72); f_rnd(blk, 64);
 463     f_rnd(blk, 56); f_rnd(blk, 48);
 464     i_rnd(blk, 40); i_rnd(blk, 32);
 465     i_rnd(blk, 24); i_rnd(blk, 16);
 466     i_rnd(blk,  8); i_rnd(blk,  0);
 467
 468     out_blk[0] = io_swap(blk[0]); out_blk[1] = io_swap(blk[1]);
 469     out_blk[2] = io_swap(blk[2]); out_blk[3] = io_swap(blk[3]);
 470 }