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
FI(u16 in,u16 subkey)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
FO(ulong32 in,int round_no,const symmetric_key * key)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
FL(ulong32 in,int round_no,const symmetric_key * key)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
kasumi_ecb_encrypt(const unsigned char * pt,unsigned char * ct,const symmetric_key * skey)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
kasumi_ecb_decrypt(const unsigned char * ct,unsigned char * pt,const symmetric_key * skey)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
kasumi_setup(const unsigned char * key,int keylen,int num_rounds,symmetric_key * skey)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
kasumi_done(symmetric_key * skey)229 void kasumi_done(symmetric_key *skey)
230 {
231 LTC_UNUSED_PARAM(skey);
232 }
233
kasumi_keysize(int * keysize)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
kasumi_test(void)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