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      1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
      2  *
      3  * LibTomCrypt is a library that provides various cryptographic
      4  * algorithms in a highly modular and flexible manner.
      5  *
      6  * The library is free for all purposes without any express
      7  * guarantee it works.
      8  *
      9  * Tom St Denis, tomstdenis (at) gmail.com, http://libtomcrypt.com
     10  */
     11 
     12 /**
     13   @file kasumi.c
     14   Implementation of the 3GPP Kasumi block cipher
     15   Derived from the 3GPP standard source code
     16 */
     17 
     18 #include "tomcrypt.h"
     19 
     20 #ifdef LTC_KASUMI
     21 
     22 typedef unsigned u16;
     23 
     24 #define ROL16(x, y) ((((x)<<(y)) | ((x)>>(16-(y)))) & 0xFFFF)
     25 
     26 const struct ltc_cipher_descriptor kasumi_desc = {
     27    "kasumi",
     28    21,
     29    16, 16, 8, 8,
     30    &kasumi_setup,
     31    &kasumi_ecb_encrypt,
     32    &kasumi_ecb_decrypt,
     33    &kasumi_test,
     34    &kasumi_done,
     35    &kasumi_keysize,
     36    NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
     37 };
     38 
     39 static u16 FI( u16 in, u16 subkey )
     40 {
     41    u16 nine, seven;
     42    static const u16 S7[128] = {
     43       54, 50, 62, 56, 22, 34, 94, 96, 38, 6, 63, 93, 2, 18,123, 33,
     44       55,113, 39,114, 21, 67, 65, 12, 47, 73, 46, 27, 25,111,124, 81,
     45       53, 9,121, 79, 52, 60, 58, 48,101,127, 40,120,104, 70, 71, 43,
     46       20,122, 72, 61, 23,109, 13,100, 77, 1, 16, 7, 82, 10,105, 98,
     47       117,116, 76, 11, 89,106, 0,125,118, 99, 86, 69, 30, 57,126, 87,
     48       112, 51, 17, 5, 95, 14, 90, 84, 91, 8, 35,103, 32, 97, 28, 66,
     49       102, 31, 26, 45, 75, 4, 85, 92, 37, 74, 80, 49, 68, 29,115, 44,
     50       64,107,108, 24,110, 83, 36, 78, 42, 19, 15, 41, 88,119, 59, 3 };
     51   static const u16 S9[512] = {
     52       167,239,161,379,391,334, 9,338, 38,226, 48,358,452,385, 90,397,
     53       183,253,147,331,415,340, 51,362,306,500,262, 82,216,159,356,177,
     54       175,241,489, 37,206, 17, 0,333, 44,254,378, 58,143,220, 81,400,
     55        95, 3,315,245, 54,235,218,405,472,264,172,494,371,290,399, 76,
     56       165,197,395,121,257,480,423,212,240, 28,462,176,406,507,288,223,
     57       501,407,249,265, 89,186,221,428,164, 74,440,196,458,421,350,163,
     58       232,158,134,354, 13,250,491,142,191, 69,193,425,152,227,366,135,
     59       344,300,276,242,437,320,113,278, 11,243, 87,317, 36, 93,496, 27,
     60       487,446,482, 41, 68,156,457,131,326,403,339, 20, 39,115,442,124,
     61       475,384,508, 53,112,170,479,151,126,169, 73,268,279,321,168,364,
     62       363,292, 46,499,393,327,324, 24,456,267,157,460,488,426,309,229,
     63       439,506,208,271,349,401,434,236, 16,209,359, 52, 56,120,199,277,
     64       465,416,252,287,246, 6, 83,305,420,345,153,502, 65, 61,244,282,
     65       173,222,418, 67,386,368,261,101,476,291,195,430, 49, 79,166,330,
     66       280,383,373,128,382,408,155,495,367,388,274,107,459,417, 62,454,
     67       132,225,203,316,234, 14,301, 91,503,286,424,211,347,307,140,374,
     68        35,103,125,427, 19,214,453,146,498,314,444,230,256,329,198,285,
     69        50,116, 78,410, 10,205,510,171,231, 45,139,467, 29, 86,505, 32,
     70        72, 26,342,150,313,490,431,238,411,325,149,473, 40,119,174,355,
     71       185,233,389, 71,448,273,372, 55,110,178,322, 12,469,392,369,190,
     72         1,109,375,137,181, 88, 75,308,260,484, 98,272,370,275,412,111,
     73       336,318, 4,504,492,259,304, 77,337,435, 21,357,303,332,483, 18,
     74        47, 85, 25,497,474,289,100,269,296,478,270,106, 31,104,433, 84,
     75       414,486,394, 96, 99,154,511,148,413,361,409,255,162,215,302,201,
     76       266,351,343,144,441,365,108,298,251, 34,182,509,138,210,335,133,
     77       311,352,328,141,396,346,123,319,450,281,429,228,443,481, 92,404,
     78       485,422,248,297, 23,213,130,466, 22,217,283, 70,294,360,419,127,
     79       312,377, 7,468,194, 2,117,295,463,258,224,447,247,187, 80,398,
     80       284,353,105,390,299,471,470,184, 57,200,348, 63,204,188, 33,451,
     81        97, 30,310,219, 94,160,129,493, 64,179,263,102,189,207,114,402,
     82       438,477,387,122,192, 42,381, 5,145,118,180,449,293,323,136,380,
     83        43, 66, 60,455,341,445,202,432, 8,237, 15,376,436,464, 59,461};
     84 
     85   /* The sixteen bit input is split into two unequal halves, *
     86    * nine bits and seven bits - as is the subkey            */
     87 
     88   nine  = (u16)(in>>7)&0x1FF;
     89   seven = (u16)(in&0x7F);
     90 
     91   /* Now run the various operations */
     92   nine   = (u16)(S9[nine] ^ seven);
     93   seven  = (u16)(S7[seven] ^ (nine & 0x7F));
     94   seven ^= (subkey>>9);
     95   nine  ^= (subkey&0x1FF);
     96   nine   = (u16)(S9[nine] ^ seven);
     97   seven  = (u16)(S7[seven] ^ (nine & 0x7F));
     98   return (u16)(seven<<9) + nine;
     99 }
    100 
    101 static ulong32 FO( ulong32 in, int round_no, symmetric_key *key)
    102 {
    103    u16 left, right;
    104 
    105   /* Split the input into two 16-bit words */
    106   left = (u16)(in>>16);
    107   right = (u16) in&0xFFFF;
    108 
    109   /* Now apply the same basic transformation three times */
    110   left ^= key->kasumi.KOi1[round_no];
    111   left = FI( left, key->kasumi.KIi1[round_no] );
    112   left ^= right;
    113 
    114   right ^= key->kasumi.KOi2[round_no];
    115   right = FI( right, key->kasumi.KIi2[round_no] );
    116   right ^= left;
    117 
    118   left ^= key->kasumi.KOi3[round_no];
    119   left = FI( left, key->kasumi.KIi3[round_no] );
    120   left ^= right;
    121 
    122   return (((ulong32)right)<<16)+left;
    123 }
    124 
    125 static ulong32 FL( ulong32 in, int round_no, symmetric_key *key )
    126 {
    127     u16 l, r, a, b;
    128     /* split out the left and right halves */
    129     l = (u16)(in>>16);
    130     r = (u16)(in)&0xFFFF;
    131     /* do the FL() operations           */
    132     a = (u16) (l & key->kasumi.KLi1[round_no]);
    133     r ^= ROL16(a,1);
    134     b = (u16)(r | key->kasumi.KLi2[round_no]);
    135     l ^= ROL16(b,1);
    136     /* put the two halves back together */
    137 
    138     return (((ulong32)l)<<16) + r;
    139 }
    140 
    141 int kasumi_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
    142 {
    143     ulong32 left, right, temp;
    144     int n;
    145 
    146     LTC_ARGCHK(pt   != NULL);
    147     LTC_ARGCHK(ct   != NULL);
    148     LTC_ARGCHK(skey != NULL);
    149 
    150     LOAD32H(left, pt);
    151     LOAD32H(right, pt+4);
    152 
    153     for (n = 0; n <= 7; ) {
    154         temp = FL(left,  n,   skey);
    155         temp = FO(temp,  n++, skey);
    156         right ^= temp;
    157         temp = FO(right, n,   skey);
    158         temp = FL(temp,  n++, skey);
    159         left ^= temp;
    160     }
    161 
    162     STORE32H(left, ct);
    163     STORE32H(right, ct+4);
    164 
    165     return CRYPT_OK;
    166 }
    167 
    168 int kasumi_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
    169 {
    170     ulong32 left, right, temp;
    171     int n;
    172 
    173     LTC_ARGCHK(pt   != NULL);
    174     LTC_ARGCHK(ct   != NULL);
    175     LTC_ARGCHK(skey != NULL);
    176 
    177     LOAD32H(left, ct);
    178     LOAD32H(right, ct+4);
    179 
    180     for (n = 7; n >= 0; ) {
    181         temp = FO(right, n,   skey);
    182         temp = FL(temp,  n--, skey);
    183         left ^= temp;
    184         temp = FL(left,  n,   skey);
    185         temp = FO(temp,  n--, skey);
    186         right ^= temp;
    187     }
    188 
    189     STORE32H(left, pt);
    190     STORE32H(right, pt+4);
    191 
    192     return CRYPT_OK;
    193 }
    194 
    195 int kasumi_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
    196 {
    197     static const u16 C[8] = { 0x0123,0x4567,0x89AB,0xCDEF, 0xFEDC,0xBA98,0x7654,0x3210 };
    198     u16 ukey[8], Kprime[8];
    199     int n;
    200 
    201     LTC_ARGCHK(key  != NULL);
    202     LTC_ARGCHK(skey != NULL);
    203 
    204     if (keylen != 16) {
    205        return CRYPT_INVALID_KEYSIZE;
    206     }
    207 
    208     if (num_rounds != 0 && num_rounds != 8) {
    209        return CRYPT_INVALID_ROUNDS;
    210     }
    211 
    212     /* Start by ensuring the subkeys are endian correct on a 16-bit basis */
    213     for (n = 0; n < 8; n++ ) {
    214         ukey[n] = (((u16)key[2*n]) << 8) | key[2*n+1];
    215     }
    216 
    217     /* Now build the K'[] keys */
    218     for (n = 0; n < 8; n++) {
    219         Kprime[n] = ukey[n] ^ C[n];
    220     }
    221 
    222     /* Finally construct the various sub keys */
    223     for(n = 0; n < 8; n++) {
    224         skey->kasumi.KLi1[n] = ROL16(ukey[n],1);
    225         skey->kasumi.KLi2[n] = Kprime[(n+2)&0x7];
    226         skey->kasumi.KOi1[n] = ROL16(ukey[(n+1)&0x7],5);
    227         skey->kasumi.KOi2[n] = ROL16(ukey[(n+5)&0x7],8);
    228         skey->kasumi.KOi3[n] = ROL16(ukey[(n+6)&0x7],13);
    229         skey->kasumi.KIi1[n] = Kprime[(n+4)&0x7];
    230         skey->kasumi.KIi2[n] = Kprime[(n+3)&0x7];
    231         skey->kasumi.KIi3[n] = Kprime[(n+7)&0x7];
    232     }
    233 
    234     return CRYPT_OK;
    235 }
    236 
    237 void kasumi_done(symmetric_key *skey)
    238 {
    239 }
    240 
    241 int kasumi_keysize(int *keysize)
    242 {
    243    LTC_ARGCHK(keysize != NULL);
    244    if (*keysize >= 16) {
    245       *keysize = 16;
    246       return CRYPT_OK;
    247    } else {
    248       return CRYPT_INVALID_KEYSIZE;
    249    }
    250 }
    251 
    252 int kasumi_test(void)
    253 {
    254 #ifndef LTC_TEST
    255    return CRYPT_NOP;
    256 #else
    257    static const struct {
    258       unsigned char key[16], pt[8], ct[8];
    259    } tests[] = {
    260 
    261 {
    262    { 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    263    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    264    { 0x4B, 0x58, 0xA7, 0x71, 0xAF, 0xC7, 0xE5, 0xE8 }
    265 },
    266 
    267 {
    268    { 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    269    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    270    { 0x7E, 0xEF, 0x11, 0x3C, 0x95, 0xBB, 0x5A, 0x77 }
    271 },
    272 
    273 {
    274    { 0x00, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    275    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    276    { 0x5F, 0x14, 0x06, 0x86, 0xD7, 0xAD, 0x5A, 0x39 },
    277 },
    278 
    279 {
    280    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
    281    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    282    { 0x2E, 0x14, 0x91, 0xCF, 0x70, 0xAA, 0x46, 0x5D }
    283 },
    284 
    285 {
    286    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00 },
    287    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    288    { 0xB5, 0x45, 0x86, 0xF4, 0xAB, 0x9A, 0xE5, 0x46 }
    289 },
    290 
    291 };
    292    unsigned char buf[2][8];
    293    symmetric_key key;
    294    int err, x;
    295 
    296    for (x = 0; x < (int)(sizeof(tests)/sizeof(tests[0])); x++) {
    297        if ((err = kasumi_setup(tests[x].key, 16, 0, &key)) != CRYPT_OK) {
    298           return err;
    299        }
    300        if ((err = kasumi_ecb_encrypt(tests[x].pt, buf[0], &key)) != CRYPT_OK) {
    301           return err;
    302        }
    303        if ((err = kasumi_ecb_decrypt(tests[x].ct, buf[1], &key)) != CRYPT_OK) {
    304           return err;
    305        }
    306        if (XMEMCMP(tests[x].pt, buf[1], 8) || XMEMCMP(tests[x].ct, buf[0], 8)) {
    307           return CRYPT_FAIL_TESTVECTOR;
    308        }
    309    }
    310    return CRYPT_OK;
    311 #endif
    312 }
    313 
    314 #endif
    315 
    316 /* $Source: /cvs/libtom/libtomcrypt/src/ciphers/kasumi.c,v $ */
    317 /* $Revision: 1.7 $ */
    318 /* $Date: 2006/11/09 03:05:44 $ */
    319