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