Mercurial > dropbear

comparison libtomcrypt/src/ciphers/safer/saferp.c @ 285:1b9e69c058d2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3) to branch 'au.asn.ucc.matt.dropbear' (head fdf4a7a3b97ae5046139915de7e40399cceb2c01)
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:23:58 +0000
parents
children 0cbe8f6dbf9e
comparison
equal deleted inserted replaced
281:997e6f7dc01e 285:1b9e69c058d2
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, [email protected], http://libtomcrypt.org
10 */
11
12 /**
13 @file saferp.c
14 SAFER+ Implementation by Tom St Denis
15 */
16 #include "tomcrypt.h"
17
18 #ifdef SAFERP
19
20 const struct ltc_cipher_descriptor saferp_desc =
21 {
22 "safer+",
23 4,
24 16, 32, 16, 8,
25 &saferp_setup,
26 &saferp_ecb_encrypt,
27 &saferp_ecb_decrypt,
28 &saferp_test,
29 &saferp_done,
30 &saferp_keysize,
31 NULL, NULL, NULL, NULL, NULL, NULL, NULL
32 };
33
34 /* ROUND(b,i)
35 *
36 * This is one forward key application. Note the basic form is
37 * key addition, substitution, key addition. The safer_ebox and safer_lbox
38 * are the exponentiation box and logarithm boxes respectively.
39 * The value of 'i' is the current round number which allows this
40 * function to be unrolled massively. Most of SAFER+'s speed
41 * comes from not having to compute indirect accesses into the
42 * array of 16 bytes b[0..15] which is the block of data
43 */
44
45 extern const unsigned char safer_ebox[], safer_lbox[];
46
47 #define ROUND(b, i) \
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
65 /* This is one inverse key application */
66 #define iROUND(b, i) \
67 b[0] = safer_lbox[(b[0] - skey->saferp.K[i+1][0]) & 255] ^ skey->saferp.K[i][0]; \
68 b[1] = (safer_ebox[(b[1] ^ skey->saferp.K[i+1][1]) & 255] - skey->saferp.K[i][1]) & 255; \
69 b[2] = (safer_ebox[(b[2] ^ skey->saferp.K[i+1][2]) & 255] - skey->saferp.K[i][2]) & 255; \
70 b[3] = safer_lbox[(b[3] - skey->saferp.K[i+1][3]) & 255] ^ skey->saferp.K[i][3]; \
71 b[4] = safer_lbox[(b[4] - skey->saferp.K[i+1][4]) & 255] ^ skey->saferp.K[i][4]; \
72 b[5] = (safer_ebox[(b[5] ^ skey->saferp.K[i+1][5]) & 255] - skey->saferp.K[i][5]) & 255; \
73 b[6] = (safer_ebox[(b[6] ^ skey->saferp.K[i+1][6]) & 255] - skey->saferp.K[i][6]) & 255; \
74 b[7] = safer_lbox[(b[7] - skey->saferp.K[i+1][7]) & 255] ^ skey->saferp.K[i][7]; \
75 b[8] = safer_lbox[(b[8] - skey->saferp.K[i+1][8]) & 255] ^ skey->saferp.K[i][8]; \
76 b[9] = (safer_ebox[(b[9] ^ skey->saferp.K[i+1][9]) & 255] - skey->saferp.K[i][9]) & 255; \
77 b[10] = (safer_ebox[(b[10] ^ skey->saferp.K[i+1][10]) & 255] - skey->saferp.K[i][10]) & 255; \
78 b[11] = safer_lbox[(b[11] - skey->saferp.K[i+1][11]) & 255] ^ skey->saferp.K[i][11]; \
79 b[12] = safer_lbox[(b[12] - skey->saferp.K[i+1][12]) & 255] ^ skey->saferp.K[i][12]; \
80 b[13] = (safer_ebox[(b[13] ^ skey->saferp.K[i+1][13]) & 255] - skey->saferp.K[i][13]) & 255; \
81 b[14] = (safer_ebox[(b[14] ^ skey->saferp.K[i+1][14]) & 255] - skey->saferp.K[i][14]) & 255; \
82 b[15] = safer_lbox[(b[15] - skey->saferp.K[i+1][15]) & 255] ^ skey->saferp.K[i][15];
83
84 /* This is a forward single layer PHT transform. */
85 #define PHT(b) \
86 b[0] = (b[0] + (b[1] = (b[0] + b[1]) & 255)) & 255; \
87 b[2] = (b[2] + (b[3] = (b[3] + b[2]) & 255)) & 255; \
88 b[4] = (b[4] + (b[5] = (b[5] + b[4]) & 255)) & 255; \
89 b[6] = (b[6] + (b[7] = (b[7] + b[6]) & 255)) & 255; \
90 b[8] = (b[8] + (b[9] = (b[9] + b[8]) & 255)) & 255; \
91 b[10] = (b[10] + (b[11] = (b[11] + b[10]) & 255)) & 255; \
92 b[12] = (b[12] + (b[13] = (b[13] + b[12]) & 255)) & 255; \
93 b[14] = (b[14] + (b[15] = (b[15] + b[14]) & 255)) & 255;
94
95 /* This is an inverse single layer PHT transform */
96 #define iPHT(b) \
97 b[15] = (b[15] - (b[14] = (b[14] - b[15]) & 255)) & 255; \
98 b[13] = (b[13] - (b[12] = (b[12] - b[13]) & 255)) & 255; \
99 b[11] = (b[11] - (b[10] = (b[10] - b[11]) & 255)) & 255; \
100 b[9] = (b[9] - (b[8] = (b[8] - b[9]) & 255)) & 255; \
101 b[7] = (b[7] - (b[6] = (b[6] - b[7]) & 255)) & 255; \
102 b[5] = (b[5] - (b[4] = (b[4] - b[5]) & 255)) & 255; \
103 b[3] = (b[3] - (b[2] = (b[2] - b[3]) & 255)) & 255; \
104 b[1] = (b[1] - (b[0] = (b[0] - b[1]) & 255)) & 255; \
105
106 /* This is the "Armenian" Shuffle. It takes the input from b and stores it in b2 */
107 #define SHUF(b, b2) \
108 b2[0] = b[8]; b2[1] = b[11]; b2[2] = b[12]; b2[3] = b[15]; \
109 b2[4] = b[2]; b2[5] = b[1]; b2[6] = b[6]; b2[7] = b[5]; \
110 b2[8] = b[10]; b2[9] = b[9]; b2[10] = b[14]; b2[11] = b[13]; \
111 b2[12] = b[0]; b2[13] = b[7]; b2[14] = b[4]; b2[15] = b[3];
112
113 /* This is the inverse shuffle. It takes from b and gives to b2 */
114 #define iSHUF(b, b2) \
115 b2[0] = b[12]; b2[1] = b[5]; b2[2] = b[4]; b2[3] = b[15]; \
116 b2[4] = b[14]; b2[5] = b[7]; b2[6] = b[6]; b2[7] = b[13]; \
117 b2[8] = b[0]; b2[9] = b[9]; b2[10] = b[8]; b2[11] = b[1]; \
118 b2[12] = b[2]; b2[13] = b[11]; b2[14] = b[10]; b2[15] = b[3];
119
120 /* The complete forward Linear Transform layer.
121 * Note that alternating usage of b and b2.
122 * Each round of LT starts in 'b' and ends in 'b2'.
123 */
124 #define LT(b, b2) \
125 PHT(b); SHUF(b, b2); \
126 PHT(b2); SHUF(b2, b); \
127 PHT(b); SHUF(b, b2); \
128 PHT(b2);
129
130 /* This is the inverse linear transform layer. */
131 #define iLT(b, b2) \
132 iPHT(b); \
133 iSHUF(b, b2); iPHT(b2); \
134 iSHUF(b2, b); iPHT(b); \
135 iSHUF(b, b2); iPHT(b2);
136
137 #ifdef LTC_SMALL_CODE
138
139 static void _round(unsigned char *b, int i, symmetric_key *skey)
140 {
141 ROUND(b, i);
142 }
143
144 static void _iround(unsigned char *b, int i, symmetric_key *skey)
145 {
146 iROUND(b, i);
147 }
148
149 static void _lt(unsigned char *b, unsigned char *b2)
150 {
151 LT(b, b2);
152 }
153
154 static void _ilt(unsigned char *b, unsigned char *b2)
155 {
156 iLT(b, b2);
157 }
158
159 #undef ROUND
160 #define ROUND(b, i) _round(b, i, skey)
161
162 #undef iROUND
163 #define iROUND(b, i) _iround(b, i, skey)
164
165 #undef LT
166 #define LT(b, b2) _lt(b, b2)
167
168 #undef iLT
169 #define iLT(b, b2) _ilt(b, b2)
170
171 #endif
172
173 /* These are the 33, 128-bit bias words for the key schedule */
174 static const unsigned char safer_bias[33][16] = {
175 { 70, 151, 177, 186, 163, 183, 16, 10, 197, 55, 179, 201, 90, 40, 172, 100},
176 { 236, 171, 170, 198, 103, 149, 88, 13, 248, 154, 246, 110, 102, 220, 5, 61},
177 { 138, 195, 216, 137, 106, 233, 54, 73, 67, 191, 235, 212, 150, 155, 104, 160},
178 { 93, 87, 146, 31, 213, 113, 92, 187, 34, 193, 190, 123, 188, 153, 99, 148},
179 { 42, 97, 184, 52, 50, 25, 253, 251, 23, 64, 230, 81, 29, 65, 68, 143},
180 { 221, 4, 128, 222, 231, 49, 214, 127, 1, 162, 247, 57, 218, 111, 35, 202},
181 { 58, 208, 28, 209, 48, 62, 18, 161, 205, 15, 224, 168, 175, 130, 89, 44},
182 { 125, 173, 178, 239, 194, 135, 206, 117, 6, 19, 2, 144, 79, 46, 114, 51},
183 { 192, 141, 207, 169, 129, 226, 196, 39, 47, 108, 122, 159, 82, 225, 21, 56},
184 { 252, 32, 66, 199, 8, 228, 9, 85, 94, 140, 20, 118, 96, 255, 223, 215},
185 { 250, 11, 33, 0, 26, 249, 166, 185, 232, 158, 98, 76, 217, 145, 80, 210},
186 { 24, 180, 7, 132, 234, 91, 164, 200, 14, 203, 72, 105, 75, 78, 156, 53},
187 { 69, 77, 84, 229, 37, 60, 12, 74, 139, 63, 204, 167, 219, 107, 174, 244},
188 { 45, 243, 124, 109, 157, 181, 38, 116, 242, 147, 83, 176, 240, 17, 237, 131},
189 { 182, 3, 22, 115, 59, 30, 142, 112, 189, 134, 27, 71, 126, 36, 86, 241},
190 { 136, 70, 151, 177, 186, 163, 183, 16, 10, 197, 55, 179, 201, 90, 40, 172},
191 { 220, 134, 119, 215, 166, 17, 251, 244, 186, 146, 145, 100, 131, 241, 51, 239},
192 { 44, 181, 178, 43, 136, 209, 153, 203, 140, 132, 29, 20, 129, 151, 113, 202},
193 { 163, 139, 87, 60, 130, 196, 82, 92, 28, 232, 160, 4, 180, 133, 74, 246},
194 { 84, 182, 223, 12, 26, 142, 222, 224, 57, 252, 32, 155, 36, 78, 169, 152},
195 { 171, 242, 96, 208, 108, 234, 250, 199, 217, 0, 212, 31, 110, 67, 188, 236},
196 { 137, 254, 122, 93, 73, 201, 50, 194, 249, 154, 248, 109, 22, 219, 89, 150},
197 { 233, 205, 230, 70, 66, 143, 10, 193, 204, 185, 101, 176, 210, 198, 172, 30},
198 { 98, 41, 46, 14, 116, 80, 2, 90, 195, 37, 123, 138, 42, 91, 240, 6},
199 { 71, 111, 112, 157, 126, 16, 206, 18, 39, 213, 76, 79, 214, 121, 48, 104},
200 { 117, 125, 228, 237, 128, 106, 144, 55, 162, 94, 118, 170, 197, 127, 61, 175},
201 { 229, 25, 97, 253, 77, 124, 183, 11, 238, 173, 75, 34, 245, 231, 115, 35},
202 { 200, 5, 225, 102, 221, 179, 88, 105, 99, 86, 15, 161, 49, 149, 23, 7},
203 { 40, 1, 45, 226, 147, 190, 69, 21, 174, 120, 3, 135, 164, 184, 56, 207},
204 { 8, 103, 9, 148, 235, 38, 168, 107, 189, 24, 52, 27, 187, 191, 114, 247},
205 { 53, 72, 156, 81, 47, 59, 85, 227, 192, 159, 216, 211, 243, 141, 177, 255},
206 { 62, 220, 134, 119, 215, 166, 17, 251, 244, 186, 146, 145, 100, 131, 241, 51}};
207
208 /**
209 Initialize the SAFER+ block cipher
210 @param key The symmetric key you wish to pass
211 @param keylen The key length in bytes
212 @param num_rounds The number of rounds desired (0 for default)
213 @param skey The key in as scheduled by this function.
214 @return CRYPT_OK if successful
215 */
216 int saferp_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
217 {
218 unsigned x, y, z;
219 unsigned char t[33];
220 static const int rounds[3] = { 8, 12, 16 };
221
222 LTC_ARGCHK(key != NULL);
223 LTC_ARGCHK(skey != NULL);
224
225 /* check arguments */
226 if (keylen != 16 && keylen != 24 && keylen != 32) {
227 return CRYPT_INVALID_KEYSIZE;
228 }
229
230 /* Is the number of rounds valid? Either use zero for default or
231 * 8,12,16 rounds for 16,24,32 byte keys
232 */
233 if (num_rounds != 0 && num_rounds != rounds[(keylen/8)-2]) {
234 return CRYPT_INVALID_ROUNDS;
235 }
236
237 /* 128 bit key version */
238 if (keylen == 16) {
239 /* copy key into t */
240 for (x = y = 0; x < 16; x++) {
241 t[x] = key[x];
242 y ^= key[x];
243 }
244 t[16] = y;
245
246 /* make round keys */
247 for (x = 0; x < 16; x++) {
248 skey->saferp.K[0][x] = t[x];
249 }
250
251 /* make the 16 other keys as a transformation of the first key */
252 for (x = 1; x < 17; x++) {
253 /* rotate 3 bits each */
254 for (y = 0; y < 17; y++) {
255 t[y] = ((t[y]<<3)|(t[y]>>5)) & 255;
256 }
257
258 /* select and add */
259 z = x;
260 for (y = 0; y < 16; y++) {
261 skey->saferp.K[x][y] = (t[z] + safer_bias[x-1][y]) & 255;
262 if (++z == 17) { z = 0; }
263 }
264 }
265 skey->saferp.rounds = 8;
266 } else if (keylen == 24) {
267 /* copy key into t */
268 for (x = y = 0; x < 24; x++) {
269 t[x] = key[x];
270 y ^= key[x];
271 }
272 t[24] = y;
273
274 /* make round keys */
275 for (x = 0; x < 16; x++) {
276 skey->saferp.K[0][x] = t[x];
277 }
278
279 for (x = 1; x < 25; x++) {
280 /* rotate 3 bits each */
281 for (y = 0; y < 25; y++) {
282 t[y] = ((t[y]<<3)|(t[y]>>5)) & 255;
283 }
284
285 /* select and add */
286 z = x;
287 for (y = 0; y < 16; y++) {
288 skey->saferp.K[x][y] = (t[z] + safer_bias[x-1][y]) & 255;
289 if (++z == 25) { z = 0; }
290 }
291 }
292 skey->saferp.rounds = 12;
293 } else {
294 /* copy key into t */
295 for (x = y = 0; x < 32; x++) {
296 t[x] = key[x];
297 y ^= key[x];
298 }
299 t[32] = y;
300
301 /* make round keys */
302 for (x = 0; x < 16; x++) {
303 skey->saferp.K[0][x] = t[x];
304 }
305
306 for (x = 1; x < 33; x++) {
307 /* rotate 3 bits each */
308 for (y = 0; y < 33; y++) {
309 t[y] = ((t[y]<<3)|(t[y]>>5)) & 255;
310 }
311
312 /* select and add */
313 z = x;
314 for (y = 0; y < 16; y++) {
315 skey->saferp.K[x][y] = (t[z] + safer_bias[x-1][y]) & 255;
316 if (++z == 33) { z = 0; }
317 }
318 }
319 skey->saferp.rounds = 16;
320 }
321 #ifdef LTC_CLEAN_STACK
322 zeromem(t, sizeof(t));
323 #endif
324 return CRYPT_OK;
325 }
326
327 /**
328 Encrypts a block of text with SAFER+
329 @param pt The input plaintext (16 bytes)
330 @param ct The output ciphertext (16 bytes)
331 @param skey The key as scheduled
332 */
333 void saferp_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
334 {
335 unsigned char b[16];
336 int x;
337
338 LTC_ARGCHK(pt != NULL);
339 LTC_ARGCHK(ct != NULL);
340 LTC_ARGCHK(skey != NULL);
341
342 /* do eight rounds */
343 for (x = 0; x < 16; x++) {
344 b[x] = pt[x];
345 }
346 ROUND(b, 0); LT(b, ct);
347 ROUND(ct, 2); LT(ct, b);
348 ROUND(b, 4); LT(b, ct);
349 ROUND(ct, 6); LT(ct, b);
350 ROUND(b, 8); LT(b, ct);
351 ROUND(ct, 10); LT(ct, b);
352 ROUND(b, 12); LT(b, ct);
353 ROUND(ct, 14); LT(ct, b);
354 /* 192-bit key? */
355 if (skey->saferp.rounds > 8) {
356 ROUND(b, 16); LT(b, ct);
357 ROUND(ct, 18); LT(ct, b);
358 ROUND(b, 20); LT(b, ct);
359 ROUND(ct, 22); LT(ct, b);
360 }
361 /* 256-bit key? */
362 if (skey->saferp.rounds > 12) {
363 ROUND(b, 24); LT(b, ct);
364 ROUND(ct, 26); LT(ct, b);
365 ROUND(b, 28); LT(b, ct);
366 ROUND(ct, 30); LT(ct, b);
367 }
368 ct[0] = b[0] ^ skey->saferp.K[skey->saferp.rounds*2][0];
369 ct[1] = (b[1] + skey->saferp.K[skey->saferp.rounds*2][1]) & 255;
370 ct[2] = (b[2] + skey->saferp.K[skey->saferp.rounds*2][2]) & 255;
371 ct[3] = b[3] ^ skey->saferp.K[skey->saferp.rounds*2][3];
372 ct[4] = b[4] ^ skey->saferp.K[skey->saferp.rounds*2][4];
373 ct[5] = (b[5] + skey->saferp.K[skey->saferp.rounds*2][5]) & 255;
374 ct[6] = (b[6] + skey->saferp.K[skey->saferp.rounds*2][6]) & 255;
375 ct[7] = b[7] ^ skey->saferp.K[skey->saferp.rounds*2][7];
376 ct[8] = b[8] ^ skey->saferp.K[skey->saferp.rounds*2][8];
377 ct[9] = (b[9] + skey->saferp.K[skey->saferp.rounds*2][9]) & 255;
378 ct[10] = (b[10] + skey->saferp.K[skey->saferp.rounds*2][10]) & 255;
379 ct[11] = b[11] ^ skey->saferp.K[skey->saferp.rounds*2][11];
380 ct[12] = b[12] ^ skey->saferp.K[skey->saferp.rounds*2][12];
381 ct[13] = (b[13] + skey->saferp.K[skey->saferp.rounds*2][13]) & 255;
382 ct[14] = (b[14] + skey->saferp.K[skey->saferp.rounds*2][14]) & 255;
383 ct[15] = b[15] ^ skey->saferp.K[skey->saferp.rounds*2][15];
384 #ifdef LTC_CLEAN_STACK
385 zeromem(b, sizeof(b));
386 #endif
387 }
388
389 /**
390 Decrypts a block of text with SAFER+
391 @param ct The input ciphertext (16 bytes)
392 @param pt The output plaintext (16 bytes)
393 @param skey The key as scheduled
394 */
395 void saferp_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
396 {
397 unsigned char b[16];
398 int x;
399
400 LTC_ARGCHK(pt != NULL);
401 LTC_ARGCHK(ct != NULL);
402 LTC_ARGCHK(skey != NULL);
403
404 /* do eight rounds */
405 b[0] = ct[0] ^ skey->saferp.K[skey->saferp.rounds*2][0];
406 b[1] = (ct[1] - skey->saferp.K[skey->saferp.rounds*2][1]) & 255;
407 b[2] = (ct[2] - skey->saferp.K[skey->saferp.rounds*2][2]) & 255;
408 b[3] = ct[3] ^ skey->saferp.K[skey->saferp.rounds*2][3];
409 b[4] = ct[4] ^ skey->saferp.K[skey->saferp.rounds*2][4];
410 b[5] = (ct[5] - skey->saferp.K[skey->saferp.rounds*2][5]) & 255;
411 b[6] = (ct[6] - skey->saferp.K[skey->saferp.rounds*2][6]) & 255;
412 b[7] = ct[7] ^ skey->saferp.K[skey->saferp.rounds*2][7];
413 b[8] = ct[8] ^ skey->saferp.K[skey->saferp.rounds*2][8];
414 b[9] = (ct[9] - skey->saferp.K[skey->saferp.rounds*2][9]) & 255;
415 b[10] = (ct[10] - skey->saferp.K[skey->saferp.rounds*2][10]) & 255;
416 b[11] = ct[11] ^ skey->saferp.K[skey->saferp.rounds*2][11];
417 b[12] = ct[12] ^ skey->saferp.K[skey->saferp.rounds*2][12];
418 b[13] = (ct[13] - skey->saferp.K[skey->saferp.rounds*2][13]) & 255;
419 b[14] = (ct[14] - skey->saferp.K[skey->saferp.rounds*2][14]) & 255;
420 b[15] = ct[15] ^ skey->saferp.K[skey->saferp.rounds*2][15];
421 /* 256-bit key? */
422 if (skey->saferp.rounds > 12) {
423 iLT(b, pt); iROUND(pt, 30);
424 iLT(pt, b); iROUND(b, 28);
425 iLT(b, pt); iROUND(pt, 26);
426 iLT(pt, b); iROUND(b, 24);
427 }
428 /* 192-bit key? */
429 if (skey->saferp.rounds > 8) {
430 iLT(b, pt); iROUND(pt, 22);
431 iLT(pt, b); iROUND(b, 20);
432 iLT(b, pt); iROUND(pt, 18);
433 iLT(pt, b); iROUND(b, 16);
434 }
435 iLT(b, pt); iROUND(pt, 14);
436 iLT(pt, b); iROUND(b, 12);
437 iLT(b, pt); iROUND(pt,10);
438 iLT(pt, b); iROUND(b, 8);
439 iLT(b, pt); iROUND(pt,6);
440 iLT(pt, b); iROUND(b, 4);
441 iLT(b, pt); iROUND(pt,2);
442 iLT(pt, b); iROUND(b, 0);
443 for (x = 0; x < 16; x++) {
444 pt[x] = b[x];
445 }
446 #ifdef LTC_CLEAN_STACK
447 zeromem(b, sizeof(b));
448 #endif
449 }
450
451 /**
452 Performs a self-test of the SAFER+ block cipher
453 @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled
454 */
455 int saferp_test(void)
456 {
457 #ifndef LTC_TEST
458 return CRYPT_NOP;
459 #else
460 static const struct {
461 int keylen;
462 unsigned char key[32], pt[16], ct[16];
463 } tests[] = {
464 {
465 16,
466 { 41, 35, 190, 132, 225, 108, 214, 174,
467 82, 144, 73, 241, 241, 187, 233, 235 },
468 { 179, 166, 219, 60, 135, 12, 62, 153,
469 36, 94, 13, 28, 6, 183, 71, 222 },
470 { 224, 31, 182, 10, 12, 255, 84, 70,
471 127, 13, 89, 249, 9, 57, 165, 220 }
472 }, {
473 24,
474 { 72, 211, 143, 117, 230, 217, 29, 42,
475 229, 192, 247, 43, 120, 129, 135, 68,
476 14, 95, 80, 0, 212, 97, 141, 190 },
477 { 123, 5, 21, 7, 59, 51, 130, 31,
478 24, 112, 146, 218, 100, 84, 206, 177 },
479 { 92, 136, 4, 63, 57, 95, 100, 0,
480 150, 130, 130, 16, 193, 111, 219, 133 }
481 }, {
482 32,
483 { 243, 168, 141, 254, 190, 242, 235, 113,
484 255, 160, 208, 59, 117, 6, 140, 126,
485 135, 120, 115, 77, 208, 190, 130, 190,
486 219, 194, 70, 65, 43, 140, 250, 48 },
487 { 127, 112, 240, 167, 84, 134, 50, 149,
488 170, 91, 104, 19, 11, 230, 252, 245 },
489 { 88, 11, 25, 36, 172, 229, 202, 213,
490 170, 65, 105, 153, 220, 104, 153, 138 }
491 }
492 };
493
494 unsigned char tmp[2][16];
495 symmetric_key skey;
496 int err, i, y;
497
498 for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
499 if ((err = saferp_setup(tests[i].key, tests[i].keylen, 0, &skey)) != CRYPT_OK) {
500 return err;
501 }
502 saferp_ecb_encrypt(tests[i].pt, tmp[0], &skey);
503 saferp_ecb_decrypt(tmp[0], tmp[1], &skey);
504
505 /* compare */
506 if (memcmp(tmp[0], tests[i].ct, 16) || memcmp(tmp[1], tests[i].pt, 16)) {
507 return CRYPT_FAIL_TESTVECTOR;
508 }
509
510 /* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */
511 for (y = 0; y < 16; y++) tmp[0][y] = 0;
512 for (y = 0; y < 1000; y++) saferp_ecb_encrypt(tmp[0], tmp[0], &skey);
513 for (y = 0; y < 1000; y++) saferp_ecb_decrypt(tmp[0], tmp[0], &skey);
514 for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
515 }
516
517 return CRYPT_OK;
518 #endif
519 }
520
521 /** Terminate the context
522 @param skey The scheduled key
523 */
524 void saferp_done(symmetric_key *skey)
525 {
526 }
527
528 /**
529 Gets suitable key size
530 @param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable.
531 @return CRYPT_OK if the input key size is acceptable.
532 */
533 int saferp_keysize(int *keysize)
534 {
535 LTC_ARGCHK(keysize != NULL);
536
537 if (*keysize < 16)
538 return CRYPT_INVALID_KEYSIZE;
539 if (*keysize < 24) {
540 *keysize = 16;
541 } else if (*keysize < 32) {
542 *keysize = 24;
543 } else {
544 *keysize = 32;
545 }
546 return CRYPT_OK;
547 }
548
549 #endif
550
551
552
553 /* $Source: /cvs/libtom/libtomcrypt/src/ciphers/safer/saferp.c,v $ */
554 /* $Revision: 1.7 $ */
555 /* $Date: 2005/05/05 14:35:58 $ */