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 saferp.c
13 LTC_SAFER+ Implementation by Tom St Denis
14 */
15 #include "tomcrypt_private.h"
16
17 #ifdef LTC_SAFERP
18
19 #define __LTC_SAFER_TAB_C__
20 #include "safer_tab.c"
21
22 const struct ltc_cipher_descriptor saferp_desc =
23 {
24 "safer+",
25 4,
26 16, 32, 16, 8,
27 &saferp_setup,
28 &saferp_ecb_encrypt,
29 &saferp_ecb_decrypt,
30 &saferp_test,
31 &saferp_done,
32 &saferp_keysize,
33 NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
34 };
35
36 /* ROUND(b,i)
37 *
38 * This is one forward key application. Note the basic form is
39 * key addition, substitution, key addition. The safer_ebox and safer_lbox
40 * are the exponentiation box and logarithm boxes respectively.
41 * The value of 'i' is the current round number which allows this
42 * function to be unrolled massively. Most of LTC_SAFER+'s speed
43 * comes from not having to compute indirect accesses into the
44 * array of 16 bytes b[0..15] which is the block of data
45 */
46
47 #define ROUND(b, i) do { \
48 b[0] = (safer_ebox[(b[0] ^ skey->saferp.K[i][0]) & 255] + skey->saferp.K[i+1][0]) & 255; \
49 b[1] = safer_lbox[(b[1] + skey->saferp.K[i][1]) & 255] ^ skey->saferp.K[i+1][1]; \
50 b[2] = safer_lbox[(b[2] + skey->saferp.K[i][2]) & 255] ^ skey->saferp.K[i+1][2]; \
51 b[3] = (safer_ebox[(b[3] ^ skey->saferp.K[i][3]) & 255] + skey->saferp.K[i+1][3]) & 255; \
52 b[4] = (safer_ebox[(b[4] ^ skey->saferp.K[i][4]) & 255] + skey->saferp.K[i+1][4]) & 255; \
53 b[5] = safer_lbox[(b[5] + skey->saferp.K[i][5]) & 255] ^ skey->saferp.K[i+1][5]; \
54 b[6] = safer_lbox[(b[6] + skey->saferp.K[i][6]) & 255] ^ skey->saferp.K[i+1][6]; \
55 b[7] = (safer_ebox[(b[7] ^ skey->saferp.K[i][7]) & 255] + skey->saferp.K[i+1][7]) & 255; \
56 b[8] = (safer_ebox[(b[8] ^ skey->saferp.K[i][8]) & 255] + skey->saferp.K[i+1][8]) & 255; \
57 b[9] = safer_lbox[(b[9] + skey->saferp.K[i][9]) & 255] ^ skey->saferp.K[i+1][9]; \
58 b[10] = safer_lbox[(b[10] + skey->saferp.K[i][10]) & 255] ^ skey->saferp.K[i+1][10]; \
59 b[11] = (safer_ebox[(b[11] ^ skey->saferp.K[i][11]) & 255] + skey->saferp.K[i+1][11]) & 255; \
60 b[12] = (safer_ebox[(b[12] ^ skey->saferp.K[i][12]) & 255] + skey->saferp.K[i+1][12]) & 255; \
61 b[13] = safer_lbox[(b[13] + skey->saferp.K[i][13]) & 255] ^ skey->saferp.K[i+1][13]; \
62 b[14] = safer_lbox[(b[14] + skey->saferp.K[i][14]) & 255] ^ skey->saferp.K[i+1][14]; \
63 b[15] = (safer_ebox[(b[15] ^ skey->saferp.K[i][15]) & 255] + skey->saferp.K[i+1][15]) & 255; \
64 } while (0)
65
66 /* This is one inverse key application */
67 #define iROUND(b, i) do { \
68 b[0] = safer_lbox[(b[0] - skey->saferp.K[i+1][0]) & 255] ^ skey->saferp.K[i][0]; \
69 b[1] = (safer_ebox[(b[1] ^ skey->saferp.K[i+1][1]) & 255] - skey->saferp.K[i][1]) & 255; \
70 b[2] = (safer_ebox[(b[2] ^ skey->saferp.K[i+1][2]) & 255] - skey->saferp.K[i][2]) & 255; \
71 b[3] = safer_lbox[(b[3] - skey->saferp.K[i+1][3]) & 255] ^ skey->saferp.K[i][3]; \
72 b[4] = safer_lbox[(b[4] - skey->saferp.K[i+1][4]) & 255] ^ skey->saferp.K[i][4]; \
73 b[5] = (safer_ebox[(b[5] ^ skey->saferp.K[i+1][5]) & 255] - skey->saferp.K[i][5]) & 255; \
74 b[6] = (safer_ebox[(b[6] ^ skey->saferp.K[i+1][6]) & 255] - skey->saferp.K[i][6]) & 255; \
75 b[7] = safer_lbox[(b[7] - skey->saferp.K[i+1][7]) & 255] ^ skey->saferp.K[i][7]; \
76 b[8] = safer_lbox[(b[8] - skey->saferp.K[i+1][8]) & 255] ^ skey->saferp.K[i][8]; \
77 b[9] = (safer_ebox[(b[9] ^ skey->saferp.K[i+1][9]) & 255] - skey->saferp.K[i][9]) & 255; \
78 b[10] = (safer_ebox[(b[10] ^ skey->saferp.K[i+1][10]) & 255] - skey->saferp.K[i][10]) & 255; \
79 b[11] = safer_lbox[(b[11] - skey->saferp.K[i+1][11]) & 255] ^ skey->saferp.K[i][11]; \
80 b[12] = safer_lbox[(b[12] - skey->saferp.K[i+1][12]) & 255] ^ skey->saferp.K[i][12]; \
81 b[13] = (safer_ebox[(b[13] ^ skey->saferp.K[i+1][13]) & 255] - skey->saferp.K[i][13]) & 255; \
82 b[14] = (safer_ebox[(b[14] ^ skey->saferp.K[i+1][14]) & 255] - skey->saferp.K[i][14]) & 255; \
83 b[15] = safer_lbox[(b[15] - skey->saferp.K[i+1][15]) & 255] ^ skey->saferp.K[i][15]; \
84 } while (0)
85
86 /* This is a forward single layer PHT transform. */
87 #define PHT(b) do { \
88 b[0] = (b[0] + (b[1] = (b[0] + b[1]) & 255)) & 255; \
89 b[2] = (b[2] + (b[3] = (b[3] + b[2]) & 255)) & 255; \
90 b[4] = (b[4] + (b[5] = (b[5] + b[4]) & 255)) & 255; \
91 b[6] = (b[6] + (b[7] = (b[7] + b[6]) & 255)) & 255; \
92 b[8] = (b[8] + (b[9] = (b[9] + b[8]) & 255)) & 255; \
93 b[10] = (b[10] + (b[11] = (b[11] + b[10]) & 255)) & 255; \
94 b[12] = (b[12] + (b[13] = (b[13] + b[12]) & 255)) & 255; \
95 b[14] = (b[14] + (b[15] = (b[15] + b[14]) & 255)) & 255; \
96 } while (0)
97
98 /* This is an inverse single layer PHT transform */
99 #define iPHT(b) do { \
100 b[15] = (b[15] - (b[14] = (b[14] - b[15]) & 255)) & 255; \
101 b[13] = (b[13] - (b[12] = (b[12] - b[13]) & 255)) & 255; \
102 b[11] = (b[11] - (b[10] = (b[10] - b[11]) & 255)) & 255; \
103 b[9] = (b[9] - (b[8] = (b[8] - b[9]) & 255)) & 255; \
104 b[7] = (b[7] - (b[6] = (b[6] - b[7]) & 255)) & 255; \
105 b[5] = (b[5] - (b[4] = (b[4] - b[5]) & 255)) & 255; \
106 b[3] = (b[3] - (b[2] = (b[2] - b[3]) & 255)) & 255; \
107 b[1] = (b[1] - (b[0] = (b[0] - b[1]) & 255)) & 255; \
108 } while (0)
109
110 /* This is the "Armenian" Shuffle. It takes the input from b and stores it in b2 */
111 #define SHUF(b, b2) do { \
112 b2[0] = b[8]; b2[1] = b[11]; b2[2] = b[12]; b2[3] = b[15]; \
113 b2[4] = b[2]; b2[5] = b[1]; b2[6] = b[6]; b2[7] = b[5]; \
114 b2[8] = b[10]; b2[9] = b[9]; b2[10] = b[14]; b2[11] = b[13]; \
115 b2[12] = b[0]; b2[13] = b[7]; b2[14] = b[4]; b2[15] = b[3]; \
116 } while (0)
117
118 /* This is the inverse shuffle. It takes from b and gives to b2 */
119 #define iSHUF(b, b2) do { \
120 b2[0] = b[12]; b2[1] = b[5]; b2[2] = b[4]; b2[3] = b[15]; \
121 b2[4] = b[14]; b2[5] = b[7]; b2[6] = b[6]; b2[7] = b[13]; \
122 b2[8] = b[0]; b2[9] = b[9]; b2[10] = b[8]; b2[11] = b[1]; \
123 b2[12] = b[2]; b2[13] = b[11]; b2[14] = b[10]; b2[15] = b[3]; \
124 } while (0)
125
126 /* The complete forward Linear Transform layer.
127 * Note that alternating usage of b and b2.
128 * Each round of LT starts in 'b' and ends in 'b2'.
129 */
130 #define LT(b, b2) do { \
131 PHT(b); SHUF(b, b2); \
132 PHT(b2); SHUF(b2, b); \
133 PHT(b); SHUF(b, b2); \
134 PHT(b2); \
135 } while (0)
136
137 /* This is the inverse linear transform layer. */
138 #define iLT(b, b2) do { \
139 iPHT(b); \
140 iSHUF(b, b2); iPHT(b2); \
141 iSHUF(b2, b); iPHT(b); \
142 iSHUF(b, b2); iPHT(b2); \
143 } while (0)
144
145 #ifdef LTC_SMALL_CODE
146
_round(unsigned char * b,int i,const symmetric_key * skey)147 static void _round(unsigned char *b, int i, const symmetric_key *skey)
148 {
149 ROUND(b, i);
150 }
151
_iround(unsigned char * b,int i,const symmetric_key * skey)152 static void _iround(unsigned char *b, int i, const symmetric_key *skey)
153 {
154 iROUND(b, i);
155 }
156
_lt(unsigned char * b,unsigned char * b2)157 static void _lt(unsigned char *b, unsigned char *b2)
158 {
159 LT(b, b2);
160 }
161
_ilt(unsigned char * b,unsigned char * b2)162 static void _ilt(unsigned char *b, unsigned char *b2)
163 {
164 iLT(b, b2);
165 }
166
167 #undef ROUND
168 #define ROUND(b, i) _round(b, i, skey)
169
170 #undef iROUND
171 #define iROUND(b, i) _iround(b, i, skey)
172
173 #undef LT
174 #define LT(b, b2) _lt(b, b2)
175
176 #undef iLT
177 #define iLT(b, b2) _ilt(b, b2)
178
179 #endif
180
181 /* These are the 33, 128-bit bias words for the key schedule */
182 static const unsigned char safer_bias[33][16] = {
183 { 70, 151, 177, 186, 163, 183, 16, 10, 197, 55, 179, 201, 90, 40, 172, 100},
184 { 236, 171, 170, 198, 103, 149, 88, 13, 248, 154, 246, 110, 102, 220, 5, 61},
185 { 138, 195, 216, 137, 106, 233, 54, 73, 67, 191, 235, 212, 150, 155, 104, 160},
186 { 93, 87, 146, 31, 213, 113, 92, 187, 34, 193, 190, 123, 188, 153, 99, 148},
187 { 42, 97, 184, 52, 50, 25, 253, 251, 23, 64, 230, 81, 29, 65, 68, 143},
188 { 221, 4, 128, 222, 231, 49, 214, 127, 1, 162, 247, 57, 218, 111, 35, 202},
189 { 58, 208, 28, 209, 48, 62, 18, 161, 205, 15, 224, 168, 175, 130, 89, 44},
190 { 125, 173, 178, 239, 194, 135, 206, 117, 6, 19, 2, 144, 79, 46, 114, 51},
191 { 192, 141, 207, 169, 129, 226, 196, 39, 47, 108, 122, 159, 82, 225, 21, 56},
192 { 252, 32, 66, 199, 8, 228, 9, 85, 94, 140, 20, 118, 96, 255, 223, 215},
193 { 250, 11, 33, 0, 26, 249, 166, 185, 232, 158, 98, 76, 217, 145, 80, 210},
194 { 24, 180, 7, 132, 234, 91, 164, 200, 14, 203, 72, 105, 75, 78, 156, 53},
195 { 69, 77, 84, 229, 37, 60, 12, 74, 139, 63, 204, 167, 219, 107, 174, 244},
196 { 45, 243, 124, 109, 157, 181, 38, 116, 242, 147, 83, 176, 240, 17, 237, 131},
197 { 182, 3, 22, 115, 59, 30, 142, 112, 189, 134, 27, 71, 126, 36, 86, 241},
198 { 136, 70, 151, 177, 186, 163, 183, 16, 10, 197, 55, 179, 201, 90, 40, 172},
199 { 220, 134, 119, 215, 166, 17, 251, 244, 186, 146, 145, 100, 131, 241, 51, 239},
200 { 44, 181, 178, 43, 136, 209, 153, 203, 140, 132, 29, 20, 129, 151, 113, 202},
201 { 163, 139, 87, 60, 130, 196, 82, 92, 28, 232, 160, 4, 180, 133, 74, 246},
202 { 84, 182, 223, 12, 26, 142, 222, 224, 57, 252, 32, 155, 36, 78, 169, 152},
203 { 171, 242, 96, 208, 108, 234, 250, 199, 217, 0, 212, 31, 110, 67, 188, 236},
204 { 137, 254, 122, 93, 73, 201, 50, 194, 249, 154, 248, 109, 22, 219, 89, 150},
205 { 233, 205, 230, 70, 66, 143, 10, 193, 204, 185, 101, 176, 210, 198, 172, 30},
206 { 98, 41, 46, 14, 116, 80, 2, 90, 195, 37, 123, 138, 42, 91, 240, 6},
207 { 71, 111, 112, 157, 126, 16, 206, 18, 39, 213, 76, 79, 214, 121, 48, 104},
208 { 117, 125, 228, 237, 128, 106, 144, 55, 162, 94, 118, 170, 197, 127, 61, 175},
209 { 229, 25, 97, 253, 77, 124, 183, 11, 238, 173, 75, 34, 245, 231, 115, 35},
210 { 200, 5, 225, 102, 221, 179, 88, 105, 99, 86, 15, 161, 49, 149, 23, 7},
211 { 40, 1, 45, 226, 147, 190, 69, 21, 174, 120, 3, 135, 164, 184, 56, 207},
212 { 8, 103, 9, 148, 235, 38, 168, 107, 189, 24, 52, 27, 187, 191, 114, 247},
213 { 53, 72, 156, 81, 47, 59, 85, 227, 192, 159, 216, 211, 243, 141, 177, 255},
214 { 62, 220, 134, 119, 215, 166, 17, 251, 244, 186, 146, 145, 100, 131, 241, 51}};
215
216 /**
217 Initialize the LTC_SAFER+ block cipher
218 @param key The symmetric key you wish to pass
219 @param keylen The key length in bytes
220 @param num_rounds The number of rounds desired (0 for default)
221 @param skey The key in as scheduled by this function.
222 @return CRYPT_OK if successful
223 */
saferp_setup(const unsigned char * key,int keylen,int num_rounds,symmetric_key * skey)224 int saferp_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
225 {
226 unsigned x, y, z;
227 unsigned char t[33];
228 static const int rounds[3] = { 8, 12, 16 };
229
230 LTC_ARGCHK(key != NULL);
231 LTC_ARGCHK(skey != NULL);
232
233 /* check arguments */
234 if (keylen != 16 && keylen != 24 && keylen != 32) {
235 return CRYPT_INVALID_KEYSIZE;
236 }
237
238 /* Is the number of rounds valid? Either use zero for default or
239 * 8,12,16 rounds for 16,24,32 byte keys
240 */
241 if (num_rounds != 0 && num_rounds != rounds[(keylen/8)-2]) {
242 return CRYPT_INVALID_ROUNDS;
243 }
244
245 /* 128 bit key version */
246 if (keylen == 16) {
247 /* copy key into t */
248 for (x = y = 0; x < 16; x++) {
249 t[x] = key[x];
250 y ^= key[x];
251 }
252 t[16] = y;
253
254 /* make round keys */
255 for (x = 0; x < 16; x++) {
256 skey->saferp.K[0][x] = t[x];
257 }
258
259 /* make the 16 other keys as a transformation of the first key */
260 for (x = 1; x < 17; x++) {
261 /* rotate 3 bits each */
262 for (y = 0; y < 17; y++) {
263 t[y] = ((t[y]<<3)|(t[y]>>5)) & 255;
264 }
265
266 /* select and add */
267 z = x;
268 for (y = 0; y < 16; y++) {
269 skey->saferp.K[x][y] = (t[z] + safer_bias[x-1][y]) & 255;
270 if (++z == 17) { z = 0; }
271 }
272 }
273 skey->saferp.rounds = 8;
274 } else if (keylen == 24) {
275 /* copy key into t */
276 for (x = y = 0; x < 24; x++) {
277 t[x] = key[x];
278 y ^= key[x];
279 }
280 t[24] = y;
281
282 /* make round keys */
283 for (x = 0; x < 16; x++) {
284 skey->saferp.K[0][x] = t[x];
285 }
286
287 for (x = 1; x < 25; x++) {
288 /* rotate 3 bits each */
289 for (y = 0; y < 25; y++) {
290 t[y] = ((t[y]<<3)|(t[y]>>5)) & 255;
291 }
292
293 /* select and add */
294 z = x;
295 for (y = 0; y < 16; y++) {
296 skey->saferp.K[x][y] = (t[z] + safer_bias[x-1][y]) & 255;
297 if (++z == 25) { z = 0; }
298 }
299 }
300 skey->saferp.rounds = 12;
301 } else {
302 /* copy key into t */
303 for (x = y = 0; x < 32; x++) {
304 t[x] = key[x];
305 y ^= key[x];
306 }
307 t[32] = y;
308
309 /* make round keys */
310 for (x = 0; x < 16; x++) {
311 skey->saferp.K[0][x] = t[x];
312 }
313
314 for (x = 1; x < 33; x++) {
315 /* rotate 3 bits each */
316 for (y = 0; y < 33; y++) {
317 t[y] = ((t[y]<<3)|(t[y]>>5)) & 255;
318 }
319
320 /* select and add */
321 z = x;
322 for (y = 0; y < 16; y++) {
323 skey->saferp.K[x][y] = (t[z] + safer_bias[x-1][y]) & 255;
324 if (++z == 33) { z = 0; }
325 }
326 }
327 skey->saferp.rounds = 16;
328 }
329 #ifdef LTC_CLEAN_STACK
330 zeromem(t, sizeof(t));
331 #endif
332 return CRYPT_OK;
333 }
334
335 /**
336 Encrypts a block of text with LTC_SAFER+
337 @param pt The input plaintext (16 bytes)
338 @param ct The output ciphertext (16 bytes)
339 @param skey The key as scheduled
340 @return CRYPT_OK if successful
341 */
saferp_ecb_encrypt(const unsigned char * pt,unsigned char * ct,const symmetric_key * skey)342 int saferp_ecb_encrypt(const unsigned char *pt, unsigned char *ct, const symmetric_key *skey)
343 {
344 unsigned char b[16];
345 int x;
346
347 LTC_ARGCHK(pt != NULL);
348 LTC_ARGCHK(ct != NULL);
349 LTC_ARGCHK(skey != NULL);
350
351 /* do eight rounds */
352 for (x = 0; x < 16; x++) {
353 b[x] = pt[x];
354 }
355 ROUND(b, 0); LT(b, ct);
356 ROUND(ct, 2); LT(ct, b);
357 ROUND(b, 4); LT(b, ct);
358 ROUND(ct, 6); LT(ct, b);
359 ROUND(b, 8); LT(b, ct);
360 ROUND(ct, 10); LT(ct, b);
361 ROUND(b, 12); LT(b, ct);
362 ROUND(ct, 14); LT(ct, b);
363 /* 192-bit key? */
364 if (skey->saferp.rounds > 8) {
365 ROUND(b, 16); LT(b, ct);
366 ROUND(ct, 18); LT(ct, b);
367 ROUND(b, 20); LT(b, ct);
368 ROUND(ct, 22); LT(ct, b);
369 }
370 /* 256-bit key? */
371 if (skey->saferp.rounds > 12) {
372 ROUND(b, 24); LT(b, ct);
373 ROUND(ct, 26); LT(ct, b);
374 ROUND(b, 28); LT(b, ct);
375 ROUND(ct, 30); LT(ct, b);
376 }
377 ct[0] = b[0] ^ skey->saferp.K[skey->saferp.rounds*2][0];
378 ct[1] = (b[1] + skey->saferp.K[skey->saferp.rounds*2][1]) & 255;
379 ct[2] = (b[2] + skey->saferp.K[skey->saferp.rounds*2][2]) & 255;
380 ct[3] = b[3] ^ skey->saferp.K[skey->saferp.rounds*2][3];
381 ct[4] = b[4] ^ skey->saferp.K[skey->saferp.rounds*2][4];
382 ct[5] = (b[5] + skey->saferp.K[skey->saferp.rounds*2][5]) & 255;
383 ct[6] = (b[6] + skey->saferp.K[skey->saferp.rounds*2][6]) & 255;
384 ct[7] = b[7] ^ skey->saferp.K[skey->saferp.rounds*2][7];
385 ct[8] = b[8] ^ skey->saferp.K[skey->saferp.rounds*2][8];
386 ct[9] = (b[9] + skey->saferp.K[skey->saferp.rounds*2][9]) & 255;
387 ct[10] = (b[10] + skey->saferp.K[skey->saferp.rounds*2][10]) & 255;
388 ct[11] = b[11] ^ skey->saferp.K[skey->saferp.rounds*2][11];
389 ct[12] = b[12] ^ skey->saferp.K[skey->saferp.rounds*2][12];
390 ct[13] = (b[13] + skey->saferp.K[skey->saferp.rounds*2][13]) & 255;
391 ct[14] = (b[14] + skey->saferp.K[skey->saferp.rounds*2][14]) & 255;
392 ct[15] = b[15] ^ skey->saferp.K[skey->saferp.rounds*2][15];
393 #ifdef LTC_CLEAN_STACK
394 zeromem(b, sizeof(b));
395 #endif
396 return CRYPT_OK;
397 }
398
399 /**
400 Decrypts a block of text with LTC_SAFER+
401 @param ct The input ciphertext (16 bytes)
402 @param pt The output plaintext (16 bytes)
403 @param skey The key as scheduled
404 @return CRYPT_OK if successful
405 */
saferp_ecb_decrypt(const unsigned char * ct,unsigned char * pt,const symmetric_key * skey)406 int saferp_ecb_decrypt(const unsigned char *ct, unsigned char *pt, const symmetric_key *skey)
407 {
408 unsigned char b[16];
409 int x;
410
411 LTC_ARGCHK(pt != NULL);
412 LTC_ARGCHK(ct != NULL);
413 LTC_ARGCHK(skey != NULL);
414
415 /* do eight rounds */
416 b[0] = ct[0] ^ skey->saferp.K[skey->saferp.rounds*2][0];
417 b[1] = (ct[1] - skey->saferp.K[skey->saferp.rounds*2][1]) & 255;
418 b[2] = (ct[2] - skey->saferp.K[skey->saferp.rounds*2][2]) & 255;
419 b[3] = ct[3] ^ skey->saferp.K[skey->saferp.rounds*2][3];
420 b[4] = ct[4] ^ skey->saferp.K[skey->saferp.rounds*2][4];
421 b[5] = (ct[5] - skey->saferp.K[skey->saferp.rounds*2][5]) & 255;
422 b[6] = (ct[6] - skey->saferp.K[skey->saferp.rounds*2][6]) & 255;
423 b[7] = ct[7] ^ skey->saferp.K[skey->saferp.rounds*2][7];
424 b[8] = ct[8] ^ skey->saferp.K[skey->saferp.rounds*2][8];
425 b[9] = (ct[9] - skey->saferp.K[skey->saferp.rounds*2][9]) & 255;
426 b[10] = (ct[10] - skey->saferp.K[skey->saferp.rounds*2][10]) & 255;
427 b[11] = ct[11] ^ skey->saferp.K[skey->saferp.rounds*2][11];
428 b[12] = ct[12] ^ skey->saferp.K[skey->saferp.rounds*2][12];
429 b[13] = (ct[13] - skey->saferp.K[skey->saferp.rounds*2][13]) & 255;
430 b[14] = (ct[14] - skey->saferp.K[skey->saferp.rounds*2][14]) & 255;
431 b[15] = ct[15] ^ skey->saferp.K[skey->saferp.rounds*2][15];
432 /* 256-bit key? */
433 if (skey->saferp.rounds > 12) {
434 iLT(b, pt); iROUND(pt, 30);
435 iLT(pt, b); iROUND(b, 28);
436 iLT(b, pt); iROUND(pt, 26);
437 iLT(pt, b); iROUND(b, 24);
438 }
439 /* 192-bit key? */
440 if (skey->saferp.rounds > 8) {
441 iLT(b, pt); iROUND(pt, 22);
442 iLT(pt, b); iROUND(b, 20);
443 iLT(b, pt); iROUND(pt, 18);
444 iLT(pt, b); iROUND(b, 16);
445 }
446 iLT(b, pt); iROUND(pt, 14);
447 iLT(pt, b); iROUND(b, 12);
448 iLT(b, pt); iROUND(pt,10);
449 iLT(pt, b); iROUND(b, 8);
450 iLT(b, pt); iROUND(pt,6);
451 iLT(pt, b); iROUND(b, 4);
452 iLT(b, pt); iROUND(pt,2);
453 iLT(pt, b); iROUND(b, 0);
454 for (x = 0; x < 16; x++) {
455 pt[x] = b[x];
456 }
457 #ifdef LTC_CLEAN_STACK
458 zeromem(b, sizeof(b));
459 #endif
460 return CRYPT_OK;
461 }
462
463 /**
464 Performs a self-test of the LTC_SAFER+ block cipher
465 @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled
466 */
saferp_test(void)467 int saferp_test(void)
468 {
469 #ifndef LTC_TEST
470 return CRYPT_NOP;
471 #else
472 static const struct {
473 int keylen;
474 unsigned char key[32], pt[16], ct[16];
475 } tests[] = {
476 {
477 16,
478 { 41, 35, 190, 132, 225, 108, 214, 174,
479 82, 144, 73, 241, 241, 187, 233, 235 },
480 { 179, 166, 219, 60, 135, 12, 62, 153,
481 36, 94, 13, 28, 6, 183, 71, 222 },
482 { 224, 31, 182, 10, 12, 255, 84, 70,
483 127, 13, 89, 249, 9, 57, 165, 220 }
484 }, {
485 24,
486 { 72, 211, 143, 117, 230, 217, 29, 42,
487 229, 192, 247, 43, 120, 129, 135, 68,
488 14, 95, 80, 0, 212, 97, 141, 190 },
489 { 123, 5, 21, 7, 59, 51, 130, 31,
490 24, 112, 146, 218, 100, 84, 206, 177 },
491 { 92, 136, 4, 63, 57, 95, 100, 0,
492 150, 130, 130, 16, 193, 111, 219, 133 }
493 }, {
494 32,
495 { 243, 168, 141, 254, 190, 242, 235, 113,
496 255, 160, 208, 59, 117, 6, 140, 126,
497 135, 120, 115, 77, 208, 190, 130, 190,
498 219, 194, 70, 65, 43, 140, 250, 48 },
499 { 127, 112, 240, 167, 84, 134, 50, 149,
500 170, 91, 104, 19, 11, 230, 252, 245 },
501 { 88, 11, 25, 36, 172, 229, 202, 213,
502 170, 65, 105, 153, 220, 104, 153, 138 }
503 }
504 };
505
506 unsigned char tmp[2][16];
507 symmetric_key skey;
508 int err, i, y;
509
510 for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
511 if ((err = saferp_setup(tests[i].key, tests[i].keylen, 0, &skey)) != CRYPT_OK) {
512 return err;
513 }
514 saferp_ecb_encrypt(tests[i].pt, tmp[0], &skey);
515 saferp_ecb_decrypt(tmp[0], tmp[1], &skey);
516
517 /* compare */
518 if (compare_testvector(tmp[0], 16, tests[i].ct, 16, "Safer+ Encrypt", i) ||
519 compare_testvector(tmp[1], 16, tests[i].pt, 16, "Safer+ Decrypt", i)) {
520 return CRYPT_FAIL_TESTVECTOR;
521 }
522
523 /* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */
524 for (y = 0; y < 16; y++) tmp[0][y] = 0;
525 for (y = 0; y < 1000; y++) saferp_ecb_encrypt(tmp[0], tmp[0], &skey);
526 for (y = 0; y < 1000; y++) saferp_ecb_decrypt(tmp[0], tmp[0], &skey);
527 for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
528 }
529
530 return CRYPT_OK;
531 #endif
532 }
533
534 /** Terminate the context
535 @param skey The scheduled key
536 */
saferp_done(symmetric_key * skey)537 void saferp_done(symmetric_key *skey)
538 {
539 LTC_UNUSED_PARAM(skey);
540 }
541
542 /**
543 Gets suitable key size
544 @param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable.
545 @return CRYPT_OK if the input key size is acceptable.
546 */
saferp_keysize(int * keysize)547 int saferp_keysize(int *keysize)
548 {
549 LTC_ARGCHK(keysize != NULL);
550
551 if (*keysize < 16) {
552 return CRYPT_INVALID_KEYSIZE;
553 }
554 if (*keysize < 24) {
555 *keysize = 16;
556 } else if (*keysize < 32) {
557 *keysize = 24;
558 } else {
559 *keysize = 32;
560 }
561 return CRYPT_OK;
562 }
563
564 #endif
565
566
567
568 /* ref: $Format:%D$ */
569 /* git commit: $Format:%H$ */
570 /* commit time: $Format:%ai$ */
571