1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis */ 2 /* SPDX-License-Identifier: Unlicense */ 3 4 /** 5 @file kasumi.c 6 Implementation of the 3GPP Kasumi block cipher 7 Derived from the 3GPP standard source code 8 */ 9 10 #include "tomcrypt_private.h" 11 12 #ifdef LTC_KASUMI 13 14 typedef unsigned u16; 15 16 #define ROL16(x, y) ((((x)<<(y)) | ((x)>>(16-(y)))) & 0xFFFF) 17 18 const struct ltc_cipher_descriptor kasumi_desc = { 19 "kasumi", 20 21, 21 16, 16, 8, 8, 22 &kasumi_setup, 23 &kasumi_ecb_encrypt, 24 &kasumi_ecb_decrypt, 25 &kasumi_test, 26 &kasumi_done, 27 &kasumi_keysize, 28 NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL 29 }; 30 31 static u16 FI( u16 in, u16 subkey ) 32 { 33 u16 nine, seven; 34 static const u16 S7[128] = { 35 54, 50, 62, 56, 22, 34, 94, 96, 38, 6, 63, 93, 2, 18,123, 33, 36 55,113, 39,114, 21, 67, 65, 12, 47, 73, 46, 27, 25,111,124, 81, 37 53, 9,121, 79, 52, 60, 58, 48,101,127, 40,120,104, 70, 71, 43, 38 20,122, 72, 61, 23,109, 13,100, 77, 1, 16, 7, 82, 10,105, 98, 39 117,116, 76, 11, 89,106, 0,125,118, 99, 86, 69, 30, 57,126, 87, 40 112, 51, 17, 5, 95, 14, 90, 84, 91, 8, 35,103, 32, 97, 28, 66, 41 102, 31, 26, 45, 75, 4, 85, 92, 37, 74, 80, 49, 68, 29,115, 44, 42 64,107,108, 24,110, 83, 36, 78, 42, 19, 15, 41, 88,119, 59, 3 }; 43 static const u16 S9[512] = { 44 167,239,161,379,391,334, 9,338, 38,226, 48,358,452,385, 90,397, 45 183,253,147,331,415,340, 51,362,306,500,262, 82,216,159,356,177, 46 175,241,489, 37,206, 17, 0,333, 44,254,378, 58,143,220, 81,400, 47 95, 3,315,245, 54,235,218,405,472,264,172,494,371,290,399, 76, 48 165,197,395,121,257,480,423,212,240, 28,462,176,406,507,288,223, 49 501,407,249,265, 89,186,221,428,164, 74,440,196,458,421,350,163, 50 232,158,134,354, 13,250,491,142,191, 69,193,425,152,227,366,135, 51 344,300,276,242,437,320,113,278, 11,243, 87,317, 36, 93,496, 27, 52 487,446,482, 41, 68,156,457,131,326,403,339, 20, 39,115,442,124, 53 475,384,508, 53,112,170,479,151,126,169, 73,268,279,321,168,364, 54 363,292, 46,499,393,327,324, 24,456,267,157,460,488,426,309,229, 55 439,506,208,271,349,401,434,236, 16,209,359, 52, 56,120,199,277, 56 465,416,252,287,246, 6, 83,305,420,345,153,502, 65, 61,244,282, 57 173,222,418, 67,386,368,261,101,476,291,195,430, 49, 79,166,330, 58 280,383,373,128,382,408,155,495,367,388,274,107,459,417, 62,454, 59 132,225,203,316,234, 14,301, 91,503,286,424,211,347,307,140,374, 60 35,103,125,427, 19,214,453,146,498,314,444,230,256,329,198,285, 61 50,116, 78,410, 10,205,510,171,231, 45,139,467, 29, 86,505, 32, 62 72, 26,342,150,313,490,431,238,411,325,149,473, 40,119,174,355, 63 185,233,389, 71,448,273,372, 55,110,178,322, 12,469,392,369,190, 64 1,109,375,137,181, 88, 75,308,260,484, 98,272,370,275,412,111, 65 336,318, 4,504,492,259,304, 77,337,435, 21,357,303,332,483, 18, 66 47, 85, 25,497,474,289,100,269,296,478,270,106, 31,104,433, 84, 67 414,486,394, 96, 99,154,511,148,413,361,409,255,162,215,302,201, 68 266,351,343,144,441,365,108,298,251, 34,182,509,138,210,335,133, 69 311,352,328,141,396,346,123,319,450,281,429,228,443,481, 92,404, 70 485,422,248,297, 23,213,130,466, 22,217,283, 70,294,360,419,127, 71 312,377, 7,468,194, 2,117,295,463,258,224,447,247,187, 80,398, 72 284,353,105,390,299,471,470,184, 57,200,348, 63,204,188, 33,451, 73 97, 30,310,219, 94,160,129,493, 64,179,263,102,189,207,114,402, 74 438,477,387,122,192, 42,381, 5,145,118,180,449,293,323,136,380, 75 43, 66, 60,455,341,445,202,432, 8,237, 15,376,436,464, 59,461}; 76 77 /* The sixteen bit input is split into two unequal halves, * 78 * nine bits and seven bits - as is the subkey */ 79 80 nine = (u16)(in>>7)&0x1FF; 81 seven = (u16)(in&0x7F); 82 83 /* Now run the various operations */ 84 nine = (u16)(S9[nine] ^ seven); 85 seven = (u16)(S7[seven] ^ (nine & 0x7F)); 86 seven ^= (subkey>>9); 87 nine ^= (subkey&0x1FF); 88 nine = (u16)(S9[nine] ^ seven); 89 seven = (u16)(S7[seven] ^ (nine & 0x7F)); 90 return (u16)(seven<<9) + nine; 91 } 92 93 static ulong32 FO( ulong32 in, int round_no, const symmetric_key *key) 94 { 95 u16 left, right; 96 97 /* Split the input into two 16-bit words */ 98 left = (u16)(in>>16); 99 right = (u16) in&0xFFFF; 100 101 /* Now apply the same basic transformation three times */ 102 left ^= key->kasumi.KOi1[round_no]; 103 left = FI( left, key->kasumi.KIi1[round_no] ); 104 left ^= right; 105 106 right ^= key->kasumi.KOi2[round_no]; 107 right = FI( right, key->kasumi.KIi2[round_no] ); 108 right ^= left; 109 110 left ^= key->kasumi.KOi3[round_no]; 111 left = FI( left, key->kasumi.KIi3[round_no] ); 112 left ^= right; 113 114 return (((ulong32)right)<<16)+left; 115 } 116 117 static ulong32 FL( ulong32 in, int round_no, const symmetric_key *key ) 118 { 119 u16 l, r, a, b; 120 /* split out the left and right halves */ 121 l = (u16)(in>>16); 122 r = (u16)(in)&0xFFFF; 123 /* do the FL() operations */ 124 a = (u16) (l & key->kasumi.KLi1[round_no]); 125 r ^= ROL16(a,1); 126 b = (u16)(r | key->kasumi.KLi2[round_no]); 127 l ^= ROL16(b,1); 128 /* put the two halves back together */ 129 130 return (((ulong32)l)<<16) + r; 131 } 132 133 int kasumi_ecb_encrypt(const unsigned char *pt, unsigned char *ct, const symmetric_key *skey) 134 { 135 ulong32 left, right, temp; 136 int n; 137 138 LTC_ARGCHK(pt != NULL); 139 LTC_ARGCHK(ct != NULL); 140 LTC_ARGCHK(skey != NULL); 141 142 LOAD32H(left, pt); 143 LOAD32H(right, pt+4); 144 145 for (n = 0; n <= 7; ) { 146 temp = FL(left, n, skey); 147 temp = FO(temp, n++, skey); 148 right ^= temp; 149 temp = FO(right, n, skey); 150 temp = FL(temp, n++, skey); 151 left ^= temp; 152 } 153 154 STORE32H(left, ct); 155 STORE32H(right, ct+4); 156 157 return CRYPT_OK; 158 } 159 160 int kasumi_ecb_decrypt(const unsigned char *ct, unsigned char *pt, const symmetric_key *skey) 161 { 162 ulong32 left, right, temp; 163 int n; 164 165 LTC_ARGCHK(pt != NULL); 166 LTC_ARGCHK(ct != NULL); 167 LTC_ARGCHK(skey != NULL); 168 169 LOAD32H(left, ct); 170 LOAD32H(right, ct+4); 171 172 for (n = 7; n >= 0; ) { 173 temp = FO(right, n, skey); 174 temp = FL(temp, n--, skey); 175 left ^= temp; 176 temp = FL(left, n, skey); 177 temp = FO(temp, n--, skey); 178 right ^= temp; 179 } 180 181 STORE32H(left, pt); 182 STORE32H(right, pt+4); 183 184 return CRYPT_OK; 185 } 186 187 int kasumi_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) 188 { 189 static const u16 C[8] = { 0x0123,0x4567,0x89AB,0xCDEF, 0xFEDC,0xBA98,0x7654,0x3210 }; 190 u16 ukey[8], Kprime[8]; 191 int n; 192 193 LTC_ARGCHK(key != NULL); 194 LTC_ARGCHK(skey != NULL); 195 196 if (keylen != 16) { 197 return CRYPT_INVALID_KEYSIZE; 198 } 199 200 if (num_rounds != 0 && num_rounds != 8) { 201 return CRYPT_INVALID_ROUNDS; 202 } 203 204 /* Start by ensuring the subkeys are endian correct on a 16-bit basis */ 205 for (n = 0; n < 8; n++ ) { 206 ukey[n] = (((u16)key[2*n]) << 8) | key[2*n+1]; 207 } 208 209 /* Now build the K'[] keys */ 210 for (n = 0; n < 8; n++) { 211 Kprime[n] = ukey[n] ^ C[n]; 212 } 213 214 /* Finally construct the various sub keys */ 215 for(n = 0; n < 8; n++) { 216 skey->kasumi.KLi1[n] = ROL16(ukey[n],1); 217 skey->kasumi.KLi2[n] = Kprime[(n+2)&0x7]; 218 skey->kasumi.KOi1[n] = ROL16(ukey[(n+1)&0x7],5); 219 skey->kasumi.KOi2[n] = ROL16(ukey[(n+5)&0x7],8); 220 skey->kasumi.KOi3[n] = ROL16(ukey[(n+6)&0x7],13); 221 skey->kasumi.KIi1[n] = Kprime[(n+4)&0x7]; 222 skey->kasumi.KIi2[n] = Kprime[(n+3)&0x7]; 223 skey->kasumi.KIi3[n] = Kprime[(n+7)&0x7]; 224 } 225 226 return CRYPT_OK; 227 } 228 229 void kasumi_done(symmetric_key *skey) 230 { 231 LTC_UNUSED_PARAM(skey); 232 } 233 234 int kasumi_keysize(int *keysize) 235 { 236 LTC_ARGCHK(keysize != NULL); 237 if (*keysize >= 16) { 238 *keysize = 16; 239 return CRYPT_OK; 240 } 241 return CRYPT_INVALID_KEYSIZE; 242 } 243 244 int kasumi_test(void) 245 { 246 #ifndef LTC_TEST 247 return CRYPT_NOP; 248 #else 249 static const struct { 250 unsigned char key[16], pt[8], ct[8]; 251 } tests[] = { 252 253 { 254 { 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, 255 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, 256 { 0x4B, 0x58, 0xA7, 0x71, 0xAF, 0xC7, 0xE5, 0xE8 } 257 }, 258 259 { 260 { 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, 261 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, 262 { 0x7E, 0xEF, 0x11, 0x3C, 0x95, 0xBB, 0x5A, 0x77 } 263 }, 264 265 { 266 { 0x00, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, 267 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, 268 { 0x5F, 0x14, 0x06, 0x86, 0xD7, 0xAD, 0x5A, 0x39 }, 269 }, 270 271 { 272 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }, 273 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, 274 { 0x2E, 0x14, 0x91, 0xCF, 0x70, 0xAA, 0x46, 0x5D } 275 }, 276 277 { 278 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00 }, 279 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, 280 { 0xB5, 0x45, 0x86, 0xF4, 0xAB, 0x9A, 0xE5, 0x46 } 281 }, 282 283 }; 284 unsigned char buf[2][8]; 285 symmetric_key key; 286 int err, x; 287 288 for (x = 0; x < (int)(sizeof(tests)/sizeof(tests[0])); x++) { 289 if ((err = kasumi_setup(tests[x].key, 16, 0, &key)) != CRYPT_OK) { 290 return err; 291 } 292 if ((err = kasumi_ecb_encrypt(tests[x].pt, buf[0], &key)) != CRYPT_OK) { 293 return err; 294 } 295 if ((err = kasumi_ecb_decrypt(tests[x].ct, buf[1], &key)) != CRYPT_OK) { 296 return err; 297 } 298 if (compare_testvector(buf[1], 8, tests[x].pt, 8, "Kasumi Decrypt", x) || 299 compare_testvector(buf[0], 8, tests[x].ct, 8, "Kasumi Encrypt", x)) { 300 return CRYPT_FAIL_TESTVECTOR; 301 } 302 } 303 return CRYPT_OK; 304 #endif 305 } 306 307 #endif 308