3 * The serpent block cipher.
5 * For more details on this algorithm, see the Serpent website at
6 * http://www.cl.cam.ac.uk/~rja14/serpent.html
9 /* nettle, low-level cryptographics library
11 * Copyright (C) 1998, 2000, 2001, Ross Anderson, Eli Biham, Lars
12 * Knudsen, Rafael R. Sevilla, Niels Möller
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 /* I've modified this code a bit so that it interoperates with lsh
30 * properly. 2000-9-5, Rafael R. Sevilla <dido@pacific.net.ph>
33 /* NOTE: The copyright notice for the original version of this code
34 * said "All rights reserved. This code is freely distributed for AES
35 * selection process. No other use is allowed." However, the authors
36 * later decided to GPL the code. /nisse */
45 #include "serpent_sboxes.h"
50 serpent_set_key(struct serpent_ctx *ctx,
51 unsigned key_size, const uint8_t *key)
54 uint32_t w[132], k[132];
56 assert(key_size >= SERPENT_MIN_KEY_SIZE);
57 assert(key_size <= SERPENT_MAX_KEY_SIZE);
59 for (i = key_size, j = 0;
64 /* Read the key in the reverse direction. Why? */
65 w[j] = READ_UINT32(key + i - 4);
70 /* Pad key, "aabbccddeeff" -> 0xccddeeff, 0x01aabb" */
71 uint32_t partial = 0x01;
73 partial = (partial << 8 ) | *key++;
81 w[i]=ROL(w[i-8]^w[i-5]^w[i-3]^w[i-1]^PHI^(i-8),11);
85 w[i]=ROL(w[i-8]^w[i-5]^w[i-3]^w[i-1]^PHI^i,11);
87 RND03(w[ 0], w[ 1], w[ 2], w[ 3], k[ 0], k[ 1], k[ 2], k[ 3]);
88 RND02(w[ 4], w[ 5], w[ 6], w[ 7], k[ 4], k[ 5], k[ 6], k[ 7]);
89 RND01(w[ 8], w[ 9], w[ 10], w[ 11], k[ 8], k[ 9], k[ 10], k[ 11]);
90 RND00(w[ 12], w[ 13], w[ 14], w[ 15], k[ 12], k[ 13], k[ 14], k[ 15]);
91 RND31(w[ 16], w[ 17], w[ 18], w[ 19], k[ 16], k[ 17], k[ 18], k[ 19]);
92 RND30(w[ 20], w[ 21], w[ 22], w[ 23], k[ 20], k[ 21], k[ 22], k[ 23]);
93 RND29(w[ 24], w[ 25], w[ 26], w[ 27], k[ 24], k[ 25], k[ 26], k[ 27]);
94 RND28(w[ 28], w[ 29], w[ 30], w[ 31], k[ 28], k[ 29], k[ 30], k[ 31]);
95 RND27(w[ 32], w[ 33], w[ 34], w[ 35], k[ 32], k[ 33], k[ 34], k[ 35]);
96 RND26(w[ 36], w[ 37], w[ 38], w[ 39], k[ 36], k[ 37], k[ 38], k[ 39]);
97 RND25(w[ 40], w[ 41], w[ 42], w[ 43], k[ 40], k[ 41], k[ 42], k[ 43]);
98 RND24(w[ 44], w[ 45], w[ 46], w[ 47], k[ 44], k[ 45], k[ 46], k[ 47]);
99 RND23(w[ 48], w[ 49], w[ 50], w[ 51], k[ 48], k[ 49], k[ 50], k[ 51]);
100 RND22(w[ 52], w[ 53], w[ 54], w[ 55], k[ 52], k[ 53], k[ 54], k[ 55]);
101 RND21(w[ 56], w[ 57], w[ 58], w[ 59], k[ 56], k[ 57], k[ 58], k[ 59]);
102 RND20(w[ 60], w[ 61], w[ 62], w[ 63], k[ 60], k[ 61], k[ 62], k[ 63]);
103 RND19(w[ 64], w[ 65], w[ 66], w[ 67], k[ 64], k[ 65], k[ 66], k[ 67]);
104 RND18(w[ 68], w[ 69], w[ 70], w[ 71], k[ 68], k[ 69], k[ 70], k[ 71]);
105 RND17(w[ 72], w[ 73], w[ 74], w[ 75], k[ 72], k[ 73], k[ 74], k[ 75]);
106 RND16(w[ 76], w[ 77], w[ 78], w[ 79], k[ 76], k[ 77], k[ 78], k[ 79]);
107 RND15(w[ 80], w[ 81], w[ 82], w[ 83], k[ 80], k[ 81], k[ 82], k[ 83]);
108 RND14(w[ 84], w[ 85], w[ 86], w[ 87], k[ 84], k[ 85], k[ 86], k[ 87]);
109 RND13(w[ 88], w[ 89], w[ 90], w[ 91], k[ 88], k[ 89], k[ 90], k[ 91]);
110 RND12(w[ 92], w[ 93], w[ 94], w[ 95], k[ 92], k[ 93], k[ 94], k[ 95]);
111 RND11(w[ 96], w[ 97], w[ 98], w[ 99], k[ 96], k[ 97], k[ 98], k[ 99]);
112 RND10(w[100], w[101], w[102], w[103], k[100], k[101], k[102], k[103]);
113 RND09(w[104], w[105], w[106], w[107], k[104], k[105], k[106], k[107]);
114 RND08(w[108], w[109], w[110], w[111], k[108], k[109], k[110], k[111]);
115 RND07(w[112], w[113], w[114], w[115], k[112], k[113], k[114], k[115]);
116 RND06(w[116], w[117], w[118], w[119], k[116], k[117], k[118], k[119]);
117 RND05(w[120], w[121], w[122], w[123], k[120], k[121], k[122], k[123]);
118 RND04(w[124], w[125], w[126], w[127], k[124], k[125], k[126], k[127]);
119 RND03(w[128], w[129], w[130], w[131], k[128], k[129], k[130], k[131]);
123 ctx->keys[i][j] = k[4*i+j];
127 serpent_encrypt(const struct serpent_ctx *ctx,
128 unsigned length, uint8_t *dst,
129 const uint8_t *plain)
131 register uint32_t x0, x1, x2, x3;
132 register uint32_t y0, y1, y2, y3;
134 FOR_BLOCKS(length, dst, plain, SERPENT_BLOCK_SIZE)
136 /* Why the reverse order? */
137 x0=READ_UINT32(plain + 12);
138 x1=READ_UINT32(plain + 8);
139 x2=READ_UINT32(plain + 4);
140 x3=READ_UINT32(plain);
142 /* Start to encrypt the plaintext x */
143 keying(x0, x1, x2, x3, ctx->keys[ 0]);
144 RND00(x0, x1, x2, x3, y0, y1, y2, y3);
145 transform(y0, y1, y2, y3, x0, x1, x2, x3);
146 keying(x0, x1, x2, x3, ctx->keys[ 1]);
147 RND01(x0, x1, x2, x3, y0, y1, y2, y3);
148 transform(y0, y1, y2, y3, x0, x1, x2, x3);
149 keying(x0, x1, x2, x3, ctx->keys[ 2]);
150 RND02(x0, x1, x2, x3, y0, y1, y2, y3);
151 transform(y0, y1, y2, y3, x0, x1, x2, x3);
152 keying(x0, x1, x2, x3, ctx->keys[ 3]);
153 RND03(x0, x1, x2, x3, y0, y1, y2, y3);
154 transform(y0, y1, y2, y3, x0, x1, x2, x3);
155 keying(x0, x1, x2, x3, ctx->keys[ 4]);
156 RND04(x0, x1, x2, x3, y0, y1, y2, y3);
157 transform(y0, y1, y2, y3, x0, x1, x2, x3);
158 keying(x0, x1, x2, x3, ctx->keys[ 5]);
159 RND05(x0, x1, x2, x3, y0, y1, y2, y3);
160 transform(y0, y1, y2, y3, x0, x1, x2, x3);
161 keying(x0, x1, x2, x3, ctx->keys[ 6]);
162 RND06(x0, x1, x2, x3, y0, y1, y2, y3);
163 transform(y0, y1, y2, y3, x0, x1, x2, x3);
164 keying(x0, x1, x2, x3, ctx->keys[ 7]);
165 RND07(x0, x1, x2, x3, y0, y1, y2, y3);
166 transform(y0, y1, y2, y3, x0, x1, x2, x3);
167 keying(x0, x1, x2, x3, ctx->keys[ 8]);
168 RND08(x0, x1, x2, x3, y0, y1, y2, y3);
169 transform(y0, y1, y2, y3, x0, x1, x2, x3);
170 keying(x0, x1, x2, x3, ctx->keys[ 9]);
171 RND09(x0, x1, x2, x3, y0, y1, y2, y3);
172 transform(y0, y1, y2, y3, x0, x1, x2, x3);
173 keying(x0, x1, x2, x3, ctx->keys[10]);
174 RND10(x0, x1, x2, x3, y0, y1, y2, y3);
175 transform(y0, y1, y2, y3, x0, x1, x2, x3);
176 keying(x0, x1, x2, x3, ctx->keys[11]);
177 RND11(x0, x1, x2, x3, y0, y1, y2, y3);
178 transform(y0, y1, y2, y3, x0, x1, x2, x3);
179 keying(x0, x1, x2, x3, ctx->keys[12]);
180 RND12(x0, x1, x2, x3, y0, y1, y2, y3);
181 transform(y0, y1, y2, y3, x0, x1, x2, x3);
182 keying(x0, x1, x2, x3, ctx->keys[13]);
183 RND13(x0, x1, x2, x3, y0, y1, y2, y3);
184 transform(y0, y1, y2, y3, x0, x1, x2, x3);
185 keying(x0, x1, x2, x3, ctx->keys[14]);
186 RND14(x0, x1, x2, x3, y0, y1, y2, y3);
187 transform(y0, y1, y2, y3, x0, x1, x2, x3);
188 keying(x0, x1, x2, x3, ctx->keys[15]);
189 RND15(x0, x1, x2, x3, y0, y1, y2, y3);
190 transform(y0, y1, y2, y3, x0, x1, x2, x3);
191 keying(x0, x1, x2, x3, ctx->keys[16]);
192 RND16(x0, x1, x2, x3, y0, y1, y2, y3);
193 transform(y0, y1, y2, y3, x0, x1, x2, x3);
194 keying(x0, x1, x2, x3, ctx->keys[17]);
195 RND17(x0, x1, x2, x3, y0, y1, y2, y3);
196 transform(y0, y1, y2, y3, x0, x1, x2, x3);
197 keying(x0, x1, x2, x3, ctx->keys[18]);
198 RND18(x0, x1, x2, x3, y0, y1, y2, y3);
199 transform(y0, y1, y2, y3, x0, x1, x2, x3);
200 keying(x0, x1, x2, x3, ctx->keys[19]);
201 RND19(x0, x1, x2, x3, y0, y1, y2, y3);
202 transform(y0, y1, y2, y3, x0, x1, x2, x3);
203 keying(x0, x1, x2, x3, ctx->keys[20]);
204 RND20(x0, x1, x2, x3, y0, y1, y2, y3);
205 transform(y0, y1, y2, y3, x0, x1, x2, x3);
206 keying(x0, x1, x2, x3, ctx->keys[21]);
207 RND21(x0, x1, x2, x3, y0, y1, y2, y3);
208 transform(y0, y1, y2, y3, x0, x1, x2, x3);
209 keying(x0, x1, x2, x3, ctx->keys[22]);
210 RND22(x0, x1, x2, x3, y0, y1, y2, y3);
211 transform(y0, y1, y2, y3, x0, x1, x2, x3);
212 keying(x0, x1, x2, x3, ctx->keys[23]);
213 RND23(x0, x1, x2, x3, y0, y1, y2, y3);
214 transform(y0, y1, y2, y3, x0, x1, x2, x3);
215 keying(x0, x1, x2, x3, ctx->keys[24]);
216 RND24(x0, x1, x2, x3, y0, y1, y2, y3);
217 transform(y0, y1, y2, y3, x0, x1, x2, x3);
218 keying(x0, x1, x2, x3, ctx->keys[25]);
219 RND25(x0, x1, x2, x3, y0, y1, y2, y3);
220 transform(y0, y1, y2, y3, x0, x1, x2, x3);
221 keying(x0, x1, x2, x3, ctx->keys[26]);
222 RND26(x0, x1, x2, x3, y0, y1, y2, y3);
223 transform(y0, y1, y2, y3, x0, x1, x2, x3);
224 keying(x0, x1, x2, x3, ctx->keys[27]);
225 RND27(x0, x1, x2, x3, y0, y1, y2, y3);
226 transform(y0, y1, y2, y3, x0, x1, x2, x3);
227 keying(x0, x1, x2, x3, ctx->keys[28]);
228 RND28(x0, x1, x2, x3, y0, y1, y2, y3);
229 transform(y0, y1, y2, y3, x0, x1, x2, x3);
230 keying(x0, x1, x2, x3, ctx->keys[29]);
231 RND29(x0, x1, x2, x3, y0, y1, y2, y3);
232 transform(y0, y1, y2, y3, x0, x1, x2, x3);
233 keying(x0, x1, x2, x3, ctx->keys[30]);
234 RND30(x0, x1, x2, x3, y0, y1, y2, y3);
235 transform(y0, y1, y2, y3, x0, x1, x2, x3);
236 keying(x0, x1, x2, x3, ctx->keys[31]);
237 RND31(x0, x1, x2, x3, y0, y1, y2, y3);
238 x0 = y0; x1 = y1; x2 = y2; x3 = y3;
239 keying(x0, x1, x2, x3, ctx->keys[32]);
241 /* The ciphertext is now in x */
243 /* Why the reverse order? */
244 WRITE_UINT32(dst, x3);
245 WRITE_UINT32(dst+4, x2);
246 WRITE_UINT32(dst+8, x1);
247 WRITE_UINT32(dst+12, x0);
252 serpent_decrypt(const struct serpent_ctx *ctx,
253 unsigned length, uint8_t *dst,
254 const uint8_t *cipher)
256 register uint32_t x0, x1, x2, x3;
257 register uint32_t y0, y1, y2, y3;
259 FOR_BLOCKS(length, dst, cipher, SERPENT_BLOCK_SIZE)
261 /* Why the reverse order? */
262 x0 = READ_UINT32(cipher + 12);
263 x1 = READ_UINT32(cipher + 8);
264 x2 = READ_UINT32(cipher + 4);
265 x3 = READ_UINT32(cipher);
267 /* Start to decrypt the ciphertext x */
268 keying(x0, x1, x2, x3, ctx->keys[32]);
269 InvRND31(x0, x1, x2, x3, y0, y1, y2, y3);
270 keying(y0, y1, y2, y3, ctx->keys[31]);
271 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
272 InvRND30(x0, x1, x2, x3, y0, y1, y2, y3);
273 keying(y0, y1, y2, y3, ctx->keys[30]);
274 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
275 InvRND29(x0, x1, x2, x3, y0, y1, y2, y3);
276 keying(y0, y1, y2, y3, ctx->keys[29]);
277 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
278 InvRND28(x0, x1, x2, x3, y0, y1, y2, y3);
279 keying(y0, y1, y2, y3, ctx->keys[28]);
280 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
281 InvRND27(x0, x1, x2, x3, y0, y1, y2, y3);
282 keying(y0, y1, y2, y3, ctx->keys[27]);
283 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
284 InvRND26(x0, x1, x2, x3, y0, y1, y2, y3);
285 keying(y0, y1, y2, y3, ctx->keys[26]);
286 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
287 InvRND25(x0, x1, x2, x3, y0, y1, y2, y3);
288 keying(y0, y1, y2, y3, ctx->keys[25]);
289 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
290 InvRND24(x0, x1, x2, x3, y0, y1, y2, y3);
291 keying(y0, y1, y2, y3, ctx->keys[24]);
292 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
293 InvRND23(x0, x1, x2, x3, y0, y1, y2, y3);
294 keying(y0, y1, y2, y3, ctx->keys[23]);
295 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
296 InvRND22(x0, x1, x2, x3, y0, y1, y2, y3);
297 keying(y0, y1, y2, y3, ctx->keys[22]);
298 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
299 InvRND21(x0, x1, x2, x3, y0, y1, y2, y3);
300 keying(y0, y1, y2, y3, ctx->keys[21]);
301 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
302 InvRND20(x0, x1, x2, x3, y0, y1, y2, y3);
303 keying(y0, y1, y2, y3, ctx->keys[20]);
304 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
305 InvRND19(x0, x1, x2, x3, y0, y1, y2, y3);
306 keying(y0, y1, y2, y3, ctx->keys[19]);
307 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
308 InvRND18(x0, x1, x2, x3, y0, y1, y2, y3);
309 keying(y0, y1, y2, y3, ctx->keys[18]);
310 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
311 InvRND17(x0, x1, x2, x3, y0, y1, y2, y3);
312 keying(y0, y1, y2, y3, ctx->keys[17]);
313 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
314 InvRND16(x0, x1, x2, x3, y0, y1, y2, y3);
315 keying(y0, y1, y2, y3, ctx->keys[16]);
316 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
317 InvRND15(x0, x1, x2, x3, y0, y1, y2, y3);
318 keying(y0, y1, y2, y3, ctx->keys[15]);
319 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
320 InvRND14(x0, x1, x2, x3, y0, y1, y2, y3);
321 keying(y0, y1, y2, y3, ctx->keys[14]);
322 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
323 InvRND13(x0, x1, x2, x3, y0, y1, y2, y3);
324 keying(y0, y1, y2, y3, ctx->keys[13]);
325 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
326 InvRND12(x0, x1, x2, x3, y0, y1, y2, y3);
327 keying(y0, y1, y2, y3, ctx->keys[12]);
328 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
329 InvRND11(x0, x1, x2, x3, y0, y1, y2, y3);
330 keying(y0, y1, y2, y3, ctx->keys[11]);
331 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
332 InvRND10(x0, x1, x2, x3, y0, y1, y2, y3);
333 keying(y0, y1, y2, y3, ctx->keys[10]);
334 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
335 InvRND09(x0, x1, x2, x3, y0, y1, y2, y3);
336 keying(y0, y1, y2, y3, ctx->keys[ 9]);
337 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
338 InvRND08(x0, x1, x2, x3, y0, y1, y2, y3);
339 keying(y0, y1, y2, y3, ctx->keys[ 8]);
340 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
341 InvRND07(x0, x1, x2, x3, y0, y1, y2, y3);
342 keying(y0, y1, y2, y3, ctx->keys[ 7]);
343 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
344 InvRND06(x0, x1, x2, x3, y0, y1, y2, y3);
345 keying(y0, y1, y2, y3, ctx->keys[ 6]);
346 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
347 InvRND05(x0, x1, x2, x3, y0, y1, y2, y3);
348 keying(y0, y1, y2, y3, ctx->keys[ 5]);
349 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
350 InvRND04(x0, x1, x2, x3, y0, y1, y2, y3);
351 keying(y0, y1, y2, y3, ctx->keys[ 4]);
352 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
353 InvRND03(x0, x1, x2, x3, y0, y1, y2, y3);
354 keying(y0, y1, y2, y3, ctx->keys[ 3]);
355 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
356 InvRND02(x0, x1, x2, x3, y0, y1, y2, y3);
357 keying(y0, y1, y2, y3, ctx->keys[ 2]);
358 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
359 InvRND01(x0, x1, x2, x3, y0, y1, y2, y3);
360 keying(y0, y1, y2, y3, ctx->keys[ 1]);
361 inv_transform(y0, y1, y2, y3, x0, x1, x2, x3);
362 InvRND00(x0, x1, x2, x3, y0, y1, y2, y3);
363 x0 = y0; x1 = y1; x2 = y2; x3 = y3;
364 keying(x0, x1, x2, x3, ctx->keys[ 0]);
366 /* The plaintext is now in x */
368 /* Why the reverse order? */
369 WRITE_UINT32(dst, x3);
370 WRITE_UINT32(dst+4, x2);
371 WRITE_UINT32(dst+8, x1);
372 WRITE_UINT32(dst+12, x0);