1// cast.cpp - written and placed in the public domain by Wei Dai and Leonard Janke 2// based on Steve Reid's public domain cast.c 3 4#include "pch.h" 5#include "cast.h" 6#include "misc.h" 7 8NAMESPACE_BEGIN(CryptoPP) 9 10/* Macros to access 8-bit bytes out of a 32-bit word */ 11#define U8a(x) GETBYTE(x,3) 12#define U8b(x) GETBYTE(x,2) 13#define U8c(x) GETBYTE(x,1) 14#define U8d(x) GETBYTE(x,0) 15 16/* CAST uses three different round functions */ 17#define f1(l, r, km, kr) \ 18 t = rotlVariable(km + r, kr); \ 19 l ^= ((S[0][U8a(t)] ^ S[1][U8b(t)]) - \ 20 S[2][U8c(t)]) + S[3][U8d(t)]; 21#define f2(l, r, km, kr) \ 22 t = rotlVariable(km ^ r, kr); \ 23 l ^= ((S[0][U8a(t)] - S[1][U8b(t)]) + \ 24 S[2][U8c(t)]) ^ S[3][U8d(t)]; 25#define f3(l, r, km, kr) \ 26 t = rotlVariable(km - r, kr); \ 27 l ^= ((S[0][U8a(t)] + S[1][U8b(t)]) ^ \ 28 S[2][U8c(t)]) - S[3][U8d(t)]; 29 30#define F1(l, r, i, j) f1(l, r, K[i], K[i+j]) 31#define F2(l, r, i, j) f2(l, r, K[i], K[i+j]) 32#define F3(l, r, i, j) f3(l, r, K[i], K[i+j]) 33 34typedef BlockGetAndPut<word32, BigEndian> Block; 35 36void CAST128::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const 37{ 38 word32 t, l, r; 39 40 /* Get inblock into l,r */ 41 Block::Get(inBlock)(l)(r); 42 /* Do the work */ 43 F1(l, r, 0, 16); 44 F2(r, l, 1, 16); 45 F3(l, r, 2, 16); 46 F1(r, l, 3, 16); 47 F2(l, r, 4, 16); 48 F3(r, l, 5, 16); 49 F1(l, r, 6, 16); 50 F2(r, l, 7, 16); 51 F3(l, r, 8, 16); 52 F1(r, l, 9, 16); 53 F2(l, r, 10, 16); 54 F3(r, l, 11, 16); 55 /* Only do full 16 rounds if key length > 80 bits */ 56 if (!reduced) { 57 F1(l, r, 12, 16); 58 F2(r, l, 13, 16); 59 F3(l, r, 14, 16); 60 F1(r, l, 15, 16); 61 } 62 /* Put l,r into outblock */ 63 Block::Put(xorBlock, outBlock)(r)(l); 64} 65 66void CAST128::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const 67{ 68 word32 t, l, r; 69 70 /* Get inblock into l,r */ 71 Block::Get(inBlock)(r)(l); 72 /* Only do full 16 rounds if key length > 80 bits */ 73 if (!reduced) { 74 F1(r, l, 15, 16); 75 F3(l, r, 14, 16); 76 F2(r, l, 13, 16); 77 F1(l, r, 12, 16); 78 } 79 F3(r, l, 11, 16); 80 F2(l, r, 10, 16); 81 F1(r, l, 9, 16); 82 F3(l, r, 8, 16); 83 F2(r, l, 7, 16); 84 F1(l, r, 6, 16); 85 F3(r, l, 5, 16); 86 F2(l, r, 4, 16); 87 F1(r, l, 3, 16); 88 F3(l, r, 2, 16); 89 F2(r, l, 1, 16); 90 F1(l, r, 0, 16); 91 /* Put l,r into outblock */ 92 Block::Put(xorBlock, outBlock)(l)(r); 93 /* Wipe clean */ 94 t = l = r = 0; 95} 96 97void CAST128::Base::UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &) 98{ 99 AssertValidKeyLength(keylength); 100 101 reduced = (keylength <= 10); 102 103 word32 X[4], Z[4]; 104 GetUserKey(BIG_ENDIAN_ORDER, X, 4, userKey, keylength); 105 106#define x(i) GETBYTE(X[i/4], 3-i%4) 107#define z(i) GETBYTE(Z[i/4], 3-i%4) 108 109 unsigned int i; 110 for (i=0; i<=16; i+=16) 111 { 112 // this part is copied directly from RFC 2144 (with some search and replace) by Wei Dai 113 Z[0] = X[0] ^ S[4][x(0xD)] ^ S[5][x(0xF)] ^ S[6][x(0xC)] ^ S[7][x(0xE)] ^ S[6][x(0x8)]; 114 Z[1] = X[2] ^ S[4][z(0x0)] ^ S[5][z(0x2)] ^ S[6][z(0x1)] ^ S[7][z(0x3)] ^ S[7][x(0xA)]; 115 Z[2] = X[3] ^ S[4][z(0x7)] ^ S[5][z(0x6)] ^ S[6][z(0x5)] ^ S[7][z(0x4)] ^ S[4][x(0x9)]; 116 Z[3] = X[1] ^ S[4][z(0xA)] ^ S[5][z(0x9)] ^ S[6][z(0xB)] ^ S[7][z(0x8)] ^ S[5][x(0xB)]; 117 K[i+0] = S[4][z(0x8)] ^ S[5][z(0x9)] ^ S[6][z(0x7)] ^ S[7][z(0x6)] ^ S[4][z(0x2)]; 118 K[i+1] = S[4][z(0xA)] ^ S[5][z(0xB)] ^ S[6][z(0x5)] ^ S[7][z(0x4)] ^ S[5][z(0x6)]; 119 K[i+2] = S[4][z(0xC)] ^ S[5][z(0xD)] ^ S[6][z(0x3)] ^ S[7][z(0x2)] ^ S[6][z(0x9)]; 120 K[i+3] = S[4][z(0xE)] ^ S[5][z(0xF)] ^ S[6][z(0x1)] ^ S[7][z(0x0)] ^ S[7][z(0xC)]; 121 X[0] = Z[2] ^ S[4][z(0x5)] ^ S[5][z(0x7)] ^ S[6][z(0x4)] ^ S[7][z(0x6)] ^ S[6][z(0x0)]; 122 X[1] = Z[0] ^ S[4][x(0x0)] ^ S[5][x(0x2)] ^ S[6][x(0x1)] ^ S[7][x(0x3)] ^ S[7][z(0x2)]; 123 X[2] = Z[1] ^ S[4][x(0x7)] ^ S[5][x(0x6)] ^ S[6][x(0x5)] ^ S[7][x(0x4)] ^ S[4][z(0x1)]; 124 X[3] = Z[3] ^ S[4][x(0xA)] ^ S[5][x(0x9)] ^ S[6][x(0xB)] ^ S[7][x(0x8)] ^ S[5][z(0x3)]; 125 K[i+4] = S[4][x(0x3)] ^ S[5][x(0x2)] ^ S[6][x(0xC)] ^ S[7][x(0xD)] ^ S[4][x(0x8)]; 126 K[i+5] = S[4][x(0x1)] ^ S[5][x(0x0)] ^ S[6][x(0xE)] ^ S[7][x(0xF)] ^ S[5][x(0xD)]; 127 K[i+6] = S[4][x(0x7)] ^ S[5][x(0x6)] ^ S[6][x(0x8)] ^ S[7][x(0x9)] ^ S[6][x(0x3)]; 128 K[i+7] = S[4][x(0x5)] ^ S[5][x(0x4)] ^ S[6][x(0xA)] ^ S[7][x(0xB)] ^ S[7][x(0x7)]; 129 Z[0] = X[0] ^ S[4][x(0xD)] ^ S[5][x(0xF)] ^ S[6][x(0xC)] ^ S[7][x(0xE)] ^ S[6][x(0x8)]; 130 Z[1] = X[2] ^ S[4][z(0x0)] ^ S[5][z(0x2)] ^ S[6][z(0x1)] ^ S[7][z(0x3)] ^ S[7][x(0xA)]; 131 Z[2] = X[3] ^ S[4][z(0x7)] ^ S[5][z(0x6)] ^ S[6][z(0x5)] ^ S[7][z(0x4)] ^ S[4][x(0x9)]; 132 Z[3] = X[1] ^ S[4][z(0xA)] ^ S[5][z(0x9)] ^ S[6][z(0xB)] ^ S[7][z(0x8)] ^ S[5][x(0xB)]; 133 K[i+8] = S[4][z(0x3)] ^ S[5][z(0x2)] ^ S[6][z(0xC)] ^ S[7][z(0xD)] ^ S[4][z(0x9)]; 134 K[i+9] = S[4][z(0x1)] ^ S[5][z(0x0)] ^ S[6][z(0xE)] ^ S[7][z(0xF)] ^ S[5][z(0xC)]; 135 K[i+10] = S[4][z(0x7)] ^ S[5][z(0x6)] ^ S[6][z(0x8)] ^ S[7][z(0x9)] ^ S[6][z(0x2)]; 136 K[i+11] = S[4][z(0x5)] ^ S[5][z(0x4)] ^ S[6][z(0xA)] ^ S[7][z(0xB)] ^ S[7][z(0x6)]; 137 X[0] = Z[2] ^ S[4][z(0x5)] ^ S[5][z(0x7)] ^ S[6][z(0x4)] ^ S[7][z(0x6)] ^ S[6][z(0x0)]; 138 X[1] = Z[0] ^ S[4][x(0x0)] ^ S[5][x(0x2)] ^ S[6][x(0x1)] ^ S[7][x(0x3)] ^ S[7][z(0x2)]; 139 X[2] = Z[1] ^ S[4][x(0x7)] ^ S[5][x(0x6)] ^ S[6][x(0x5)] ^ S[7][x(0x4)] ^ S[4][z(0x1)]; 140 X[3] = Z[3] ^ S[4][x(0xA)] ^ S[5][x(0x9)] ^ S[6][x(0xB)] ^ S[7][x(0x8)] ^ S[5][z(0x3)]; 141 K[i+12] = S[4][x(0x8)] ^ S[5][x(0x9)] ^ S[6][x(0x7)] ^ S[7][x(0x6)] ^ S[4][x(0x3)]; 142 K[i+13] = S[4][x(0xA)] ^ S[5][x(0xB)] ^ S[6][x(0x5)] ^ S[7][x(0x4)] ^ S[5][x(0x7)]; 143 K[i+14] = S[4][x(0xC)] ^ S[5][x(0xD)] ^ S[6][x(0x3)] ^ S[7][x(0x2)] ^ S[6][x(0x8)]; 144 K[i+15] = S[4][x(0xE)] ^ S[5][x(0xF)] ^ S[6][x(0x1)] ^ S[7][x(0x0)] ^ S[7][x(0xD)]; 145 } 146 147 for (i=16; i<32; i++) 148 K[i] &= 0x1f; 149} 150 151// The following CAST-256 implementation was contributed by Leonard Janke 152 153const word32 CAST256::Base::t_m[8][24]={ 154{ 0x5a827999, 0xd151d6a1, 0x482133a9, 0xbef090b1, 0x35bfedb9, 0xac8f4ac1, 155 0x235ea7c9, 0x9a2e04d1, 0x10fd61d9, 0x87ccbee1, 0xfe9c1be9, 0x756b78f1, 156 0xec3ad5f9, 0x630a3301, 0xd9d99009, 0x50a8ed11, 0xc7784a19, 0x3e47a721, 157 0xb5170429, 0x2be66131, 0xa2b5be39, 0x19851b41, 0x90547849, 0x0723d551}, 158{ 0xc95c653a, 0x402bc242, 0xb6fb1f4a, 0x2dca7c52, 0xa499d95a, 0x1b693662, 159 0x9238936a, 0x0907f072, 0x7fd74d7a, 0xf6a6aa82, 0x6d76078a, 0xe4456492, 160 0x5b14c19a, 0xd1e41ea2, 0x48b37baa, 0xbf82d8b2, 0x365235ba, 0xad2192c2, 161 0x23f0efca, 0x9ac04cd2, 0x118fa9da, 0x885f06e2, 0xff2e63ea, 0x75fdc0f2}, 162{ 0x383650db, 0xaf05ade3, 0x25d50aeb, 0x9ca467f3, 0x1373c4fb, 0x8a432203, 163 0x01127f0b, 0x77e1dc13, 0xeeb1391b, 0x65809623, 0xdc4ff32b, 0x531f5033, 164 0xc9eead3b, 0x40be0a43, 0xb78d674b, 0x2e5cc453, 0xa52c215b, 0x1bfb7e63, 165 0x92cadb6b, 0x099a3873, 0x8069957b, 0xf738f283, 0x6e084f8b, 0xe4d7ac93}, 166{ 0xa7103c7c, 0x1ddf9984, 0x94aef68c, 0x0b7e5394, 0x824db09c, 0xf91d0da4, 167 0x6fec6aac, 0xe6bbc7b4, 0x5d8b24bc, 0xd45a81c4, 0x4b29decc, 0xc1f93bd4, 168 0x38c898dc, 0xaf97f5e4, 0x266752ec, 0x9d36aff4, 0x14060cfc, 0x8ad56a04, 169 0x01a4c70c, 0x78742414, 0xef43811c, 0x6612de24, 0xdce23b2c, 0x53b19834}, 170{ 0x15ea281d, 0x8cb98525, 0x0388e22d, 0x7a583f35, 0xf1279c3d, 0x67f6f945, 171 0xdec6564d, 0x5595b355, 0xcc65105d, 0x43346d65, 0xba03ca6d, 0x30d32775, 172 0xa7a2847d, 0x1e71e185, 0x95413e8d, 0x0c109b95, 0x82dff89d, 0xf9af55a5, 173 0x707eb2ad, 0xe74e0fb5, 0x5e1d6cbd, 0xd4ecc9c5, 0x4bbc26cd, 0xc28b83d5}, 174{ 0x84c413be, 0xfb9370c6, 0x7262cdce, 0xe9322ad6, 0x600187de, 0xd6d0e4e6, 175 0x4da041ee, 0xc46f9ef6, 0x3b3efbfe, 0xb20e5906, 0x28ddb60e, 0x9fad1316, 176 0x167c701e, 0x8d4bcd26, 0x041b2a2e, 0x7aea8736, 0xf1b9e43e, 0x68894146, 177 0xdf589e4e, 0x5627fb56, 0xccf7585e, 0x43c6b566, 0xba96126e, 0x31656f76}, 178{ 0xf39dff5f, 0x6a6d5c67, 0xe13cb96f, 0x580c1677, 0xcedb737f, 0x45aad087, 179 0xbc7a2d8f, 0x33498a97, 0xaa18e79f, 0x20e844a7, 0x97b7a1af, 0x0e86feb7, 180 0x85565bbf, 0xfc25b8c7, 0x72f515cf, 0xe9c472d7, 0x6093cfdf, 0xd7632ce7, 181 0x4e3289ef, 0xc501e6f7, 0x3bd143ff, 0xb2a0a107, 0x296ffe0f, 0xa03f5b17}, 182{ 0x6277eb00, 0xd9474808, 0x5016a510, 0xc6e60218, 0x3db55f20, 0xb484bc28, 183 0x2b541930, 0xa2237638, 0x18f2d340, 0x8fc23048, 0x06918d50, 0x7d60ea58, 184 0xf4304760, 0x6affa468, 0xe1cf0170, 0x589e5e78, 0xcf6dbb80, 0x463d1888, 185 0xbd0c7590, 0x33dbd298, 0xaaab2fa0, 0x217a8ca8, 0x9849e9b0, 0x0f1946b8} 186}; 187 188const unsigned int CAST256::Base::t_r[8][24]={ 189 {19, 27, 3, 11, 19, 27, 3, 11, 19, 27, 3, 11, 19, 27, 3, 11, 19, 27, 3, 11, 19, 27, 3, 11}, 190 {4, 12, 20, 28, 4, 12, 20, 28, 4, 12, 20, 28, 4, 12, 20, 28, 4, 12, 20, 28, 4, 12, 20, 28}, 191 {21, 29, 5, 13, 21, 29, 5, 13, 21, 29, 5, 13, 21, 29, 5, 13, 21, 29, 5, 13, 21, 29, 5, 13}, 192 {6, 14, 22, 30, 6, 14, 22, 30, 6, 14, 22, 30, 6, 14, 22, 30, 6, 14, 22, 30, 6, 14, 22, 30}, 193 {23, 31, 7, 15, 23, 31, 7, 15, 23, 31, 7, 15, 23, 31, 7, 15, 23, 31, 7, 15, 23, 31, 7, 15}, 194 {8, 16, 24, 0, 8, 16, 24, 0, 8, 16, 24, 0, 8, 16, 24, 0, 8, 16, 24, 0, 8, 16, 24, 0}, 195 {25, 1, 9, 17, 25, 1, 9, 17, 25, 1, 9, 17, 25, 1, 9, 17, 25, 1, 9, 17, 25, 1, 9, 17}, 196 {10, 18, 26, 2, 10, 18, 26, 2, 10, 18, 26, 2, 10, 18, 26, 2, 10, 18, 26, 2, 10, 18, 26, 2} 197}; 198 199#define Q(i) \ 200 F1(block[2],block[3],8*i+4,-4); \ 201 F2(block[1],block[2],8*i+5,-4); \ 202 F3(block[0],block[1],8*i+6,-4); \ 203 F1(block[3],block[0],8*i+7,-4); 204 205#define QBar(i) \ 206 F1(block[3],block[0],8*i+7,-4); \ 207 F3(block[0],block[1],8*i+6,-4); \ 208 F2(block[1],block[2],8*i+5,-4); \ 209 F1(block[2],block[3],8*i+4,-4); 210 211/* CAST256's encrypt/decrypt functions are identical except for the order that 212the keys are used */ 213 214void CAST256::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const 215{ 216 word32 t, block[4]; 217 Block::Get(inBlock)(block[0])(block[1])(block[2])(block[3]); 218 219 // Perform 6 forward quad rounds 220 Q(0); 221 Q(1); 222 Q(2); 223 Q(3); 224 Q(4); 225 Q(5); 226 227 // Perform 6 reverse quad rounds 228 QBar(6); 229 QBar(7); 230 QBar(8); 231 QBar(9); 232 QBar(10); 233 QBar(11); 234 235 Block::Put(xorBlock, outBlock)(block[0])(block[1])(block[2])(block[3]); 236} 237 238/* Set up a CAST-256 key */ 239 240void CAST256::Base::Omega(int i, word32 kappa[8]) 241{ 242 word32 t; 243 244 f1(kappa[6],kappa[7],t_m[0][i],t_r[0][i]); 245 f2(kappa[5],kappa[6],t_m[1][i],t_r[1][i]); 246 f3(kappa[4],kappa[5],t_m[2][i],t_r[2][i]); 247 f1(kappa[3],kappa[4],t_m[3][i],t_r[3][i]); 248 f2(kappa[2],kappa[3],t_m[4][i],t_r[4][i]); 249 f3(kappa[1],kappa[2],t_m[5][i],t_r[5][i]); 250 f1(kappa[0],kappa[1],t_m[6][i],t_r[6][i]); 251 f2(kappa[7],kappa[0],t_m[7][i],t_r[7][i]); 252} 253 254void CAST256::Base::UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &) 255{ 256 AssertValidKeyLength(keylength); 257 258 word32 kappa[8]; 259 GetUserKey(BIG_ENDIAN_ORDER, kappa, 8, userKey, keylength); 260 261 for(int i=0; i<12; ++i) 262 { 263 Omega(2*i,kappa); 264 Omega(2*i+1,kappa); 265 266 K[8*i]=kappa[0] & 31; 267 K[8*i+1]=kappa[2] & 31; 268 K[8*i+2]=kappa[4] & 31; 269 K[8*i+3]=kappa[6] & 31; 270 K[8*i+4]=kappa[7]; 271 K[8*i+5]=kappa[5]; 272 K[8*i+6]=kappa[3]; 273 K[8*i+7]=kappa[1]; 274 } 275 276 if (!IsForwardTransformation()) 277 { 278 for(int j=0; j<6; ++j) 279 { 280 for(int i=0; i<4; ++i) 281 { 282 int i1=8*j+i; 283 int i2=8*(11-j)+i; 284 285 assert(i1<i2); 286 287 std::swap(K[i1],K[i2]); 288 std::swap(K[i1+4],K[i2+4]); 289 } 290 } 291 } 292 293 memset(kappa, 0, sizeof(kappa)); 294} 295 296NAMESPACE_END 297