1 /*
2 * Copyright 2014-2022 The GmSSL Project. All Rights Reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the License); you may
5 * not use this file except in compliance with the License.
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 */
9
10
11
12 #include <stdio.h>
13 #include <string.h>
14 #include <stdlib.h>
15 #include <gmssl/aes.h>
16 #include <gmssl/endian.h>
17 #include <gmssl/mem.h>
18
19
20 static const uint8_t S[256] = {
21 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
22 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
23 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
24 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
25 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
26 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
27 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
28 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
29 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
30 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
31 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
32 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
33 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
34 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
35 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
36 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16,
37 };
38
39 static const uint8_t S_inv[256] = {
40 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
41 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
42 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
43 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
44 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
45 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
46 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
47 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
48 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
49 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
50 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
51 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
52 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
53 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
54 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
55 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d,
56 };
57
58 static const uint8_t Rcon[11] = {
59 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36,
60 };
61
sub_word(uint32_t A)62 static uint32_t sub_word(uint32_t A)
63 {
64 return S[(A >> 24) & 0xff] << 24 |
65 S[(A >> 16) & 0xff] << 16 |
66 S[(A >> 8) & 0xff] << 8 |
67 S[A & 0xff];
68 }
69
70 /* (a0,a1,a2,a3) => (a1,a2,a3,a0) */
rot_word(uint32_t A)71 static uint32_t rot_word(uint32_t A)
72 {
73 return ROL32(A, 8);
74 }
75
76 #ifdef CRYPTO_INFO
print_rk(const AES_KEY * aes_key)77 static void print_rk(const AES_KEY *aes_key)
78 {
79 size_t i;
80 for (i = 0; i <= aes_key->rounds; i++) {
81 printf("%08x ", aes_key->rk[4 * i]);
82 printf("%08x ", aes_key->rk[4 * i + 1]);
83 printf("%08x ", aes_key->rk[4 * i + 2]);
84 printf("%08x\n", aes_key->rk[4 * i + 3]);
85 }
86 printf("\n");
87 }
88 #endif
89
aes_set_encrypt_key(AES_KEY * aes_key,const uint8_t * key,size_t keylen)90 int aes_set_encrypt_key(AES_KEY *aes_key, const uint8_t *key, size_t keylen)
91 {
92 /* Nk: num user key words
93 * AES-128 Nk = 4 W[44]
94 * AES-192 Nk = 6 W[52]
95 * AES-256 Nk = 8 W[60]
96 */
97 uint32_t *W = (uint32_t *)aes_key->rk;
98 size_t Nk = keylen/sizeof(uint32_t);
99 size_t i;
100
101 switch (keylen) {
102 case AES128_KEY_SIZE:
103 aes_key->rounds = 10;
104 break;
105 case AES192_KEY_SIZE:
106 aes_key->rounds = 12;
107 break;
108 case AES256_KEY_SIZE:
109 aes_key->rounds = 14;
110 break;
111 default:
112 return 0;
113 }
114
115 for (i = 0; i < Nk; i++) {
116 W[i] = GETU32(key + sizeof(uint32_t) * i);
117 }
118 for (; i < 4 * (aes_key->rounds + 1); i++) {
119 uint32_t T = W[i - 1];
120 if (i % Nk == 0) {
121 T = rot_word(T);
122 T = sub_word(T);
123 T ^= ((uint32_t)Rcon[i/Nk] << 24);
124
125 } else if (Nk == 8 && i % 8 == 4) {
126 T = sub_word(T);
127 }
128 W[i] = W[i - Nk] ^ T;
129 }
130
131 #ifdef CRYPTO_INFO
132 print_rk(aes_key);
133 #endif
134
135 return 1;
136 }
137
aes_set_decrypt_key(AES_KEY * aes_key,const uint8_t * key,size_t keylen)138 int aes_set_decrypt_key(AES_KEY *aes_key, const uint8_t *key, size_t keylen)
139 {
140 int ret = 0;
141 AES_KEY enc_key;
142 size_t i;
143
144 if (!aes_set_encrypt_key(&enc_key, key, keylen)) {
145 goto end;
146 }
147
148 for (i = 0; i <= enc_key.rounds; i++) {
149 aes_key->rk[4*i ] = enc_key.rk[4*(enc_key.rounds - i)];
150 aes_key->rk[4*i + 1] = enc_key.rk[4*(enc_key.rounds - i) + 1];
151 aes_key->rk[4*i + 2] = enc_key.rk[4*(enc_key.rounds - i) + 2];
152 aes_key->rk[4*i + 3] = enc_key.rk[4*(enc_key.rounds - i) + 3];
153 }
154 aes_key->rounds = enc_key.rounds;
155 ret = 1;
156
157 #ifdef CRYPTO_INFO
158 print_rk(aes_key);
159 #endif
160
161 end:
162 memset(&enc_key, 0, sizeof(AES_KEY));
163 return ret;
164 }
165
166 /*
167 * |S00 S01 S02 S03| | |
168 * |S10 S11 S12 S13| xor |W0 W1 W2 W3|
169 * |S20 S21 S22 S23| | |
170 * |S30 S31 S32 S33| | |
171 */
add_round_key(uint8_t state[4][4],const uint32_t * W)172 static void add_round_key(uint8_t state[4][4], const uint32_t *W)
173 {
174 int i;
175 for (i = 0; i < 4; i++) {
176 state[0][i] ^= (W[i] >> 24) & 0xff;
177 state[1][i] ^= (W[i] >> 16) & 0xff;
178 state[2][i] ^= (W[i] >> 8) & 0xff;
179 state[3][i] ^= (W[i] ) & 0xff;
180 }
181 }
182
sub_bytes(uint8_t state[4][4])183 static void sub_bytes(uint8_t state[4][4])
184 {
185 int i, j;
186 for (i = 0; i < 4; i++) {
187 for (j = 0; j < 4; j++) {
188 state[i][j] = S[state[i][j]];
189 }
190 }
191 }
192
inv_sub_bytes(uint8_t state[4][4])193 static void inv_sub_bytes(uint8_t state[4][4])
194 {
195 int i, j;
196 for (i = 0; i < 4; i++) {
197 for (j = 0; j < 4; j++) {
198 state[i][j] = S_inv[state[i][j]];
199 }
200 }
201 }
202
203 /*
204 * |S00 S01 S02 S03| <<<0 |S00 S01 S02 S03|
205 * |S10 S11 S12 S13| <<<1 => |S11 S12 S13 S10|
206 * |S20 S21 S22 S23| <<<2 |S22 S23 S20 S21|
207 * |S30 S31 S32 S33| <<<3 |S33 S30 S31 S32|
208 */
shift_rows(uint8_t state[4][4])209 static void shift_rows(uint8_t state[4][4])
210 {
211 uint8_t tmp[4][4];
212
213 tmp[0][0] = state[0][0];
214 tmp[0][1] = state[0][1];
215 tmp[0][2] = state[0][2];
216 tmp[0][3] = state[0][3];
217
218 tmp[1][0] = state[1][1];
219 tmp[1][1] = state[1][2];
220 tmp[1][2] = state[1][3];
221 tmp[1][3] = state[1][0];
222
223 tmp[2][0] = state[2][2];
224 tmp[2][1] = state[2][3];
225 tmp[2][2] = state[2][0];
226 tmp[2][3] = state[2][1];
227
228 tmp[3][0] = state[3][3];
229 tmp[3][1] = state[3][0];
230 tmp[3][2] = state[3][1];
231 tmp[3][3] = state[3][2];
232
233 memcpy(state, tmp, sizeof(tmp));
234 memset(tmp, 0, sizeof(tmp));
235 }
236
237
238 /*
239 * |S00 S01 S02 S03| >>>0 |S00 S01 S02 S03|
240 * |S10 S11 S12 S13| >>>1 => |S13 S10 S11 S12|
241 * |S20 S21 S22 S23| >>>2 |S22 S23 S20 S21|
242 * |S30 S31 S32 S33| >>>3 |S31 S32 S33 S30|
243 */
inv_shift_rows(uint8_t state[4][4])244 static void inv_shift_rows(uint8_t state[4][4])
245 {
246 uint8_t tmp[4][4];
247
248 tmp[0][0] = state[0][0];
249 tmp[0][1] = state[0][1];
250 tmp[0][2] = state[0][2];
251 tmp[0][3] = state[0][3];
252
253 tmp[1][0] = state[1][3];
254 tmp[1][1] = state[1][0];
255 tmp[1][2] = state[1][1];
256 tmp[1][3] = state[1][2];
257
258 tmp[2][0] = state[2][2];
259 tmp[2][1] = state[2][3];
260 tmp[2][2] = state[2][0];
261 tmp[2][3] = state[2][1];
262
263 tmp[3][0] = state[3][1];
264 tmp[3][1] = state[3][2];
265 tmp[3][2] = state[3][3];
266 tmp[3][3] = state[3][0];
267
268 memcpy(state, tmp, sizeof(tmp));
269 memset(tmp, 0, sizeof(tmp));
270 }
271
272 /*
273 * GF(2^8) defSed by f(x) = x^8 + x^4 + x^3 + x + 1
274 * x^8 == x^4 + x^3 + x + 1 = 0001,1011 = 0x1b
275 * if A[7] == 0 then 2 * A = (A << 1)
276 * else 2 * A = (A << 1) xor A
277 */
278 #define x1(a) (a)
279
x2(uint8_t a)280 static uint8_t x2(uint8_t a) {
281 return (a >> 7) ? ((a << 1) ^ 0x1b) : (a << 1);
282 }
283
x3(uint8_t a)284 static uint8_t x3(uint8_t a) {
285 return x2(a) ^ x1(a);
286 }
287
x9(uint8_t a)288 static uint8_t x9(uint8_t a) {
289 return x2(x2(x2(a))) ^ x1(a);
290 }
291
292 /* 0x0b = 11 = 8 + 2 + 1 */
xb(uint8_t a)293 static uint8_t xb(uint8_t a) {
294 return x2(x2(x2(a))) ^ x2(a) ^ x1(a);
295 }
296
297 /* 0x0d = 13 = 8 + 4 + 1 */
xd(uint8_t a)298 static uint8_t xd(uint8_t a) {
299 return x2(x2(x2(a))) ^ x2(x2(a)) ^ x1(a);
300 }
301
302 /* 0x0e = 14 = 8 + 4 + 2 */
xe(uint8_t a)303 static uint8_t xe(uint8_t a) {
304 return x2(x2(x2(a))) ^ x2(x2(a)) ^ x2(a);
305 }
306
307 /*
308 * |2 3 1 1| |S00 S01 S02 S03|
309 * |1 2 3 1| |S10 S11 S12 S13|
310 * |1 1 2 3|*|S20 S21 S22 S23|
311 * |3 1 1 2| |S30 S31 S32 S33|
312 */
mix_columns(uint8_t S[4][4])313 static void mix_columns(uint8_t S[4][4])
314 {
315 uint8_t tmp[4][4];
316 int i;
317
318 /* i-th column */
319 for (i = 0; i < 4; i++) {
320 tmp[0][i] = x2(S[0][i]) ^ x3(S[1][i]) ^ x1(S[2][i]) ^ x1(S[3][i]);
321 tmp[1][i] = x1(S[0][i]) ^ x2(S[1][i]) ^ x3(S[2][i]) ^ x1(S[3][i]);
322 tmp[2][i] = x1(S[0][i]) ^ x1(S[1][i]) ^ x2(S[2][i]) ^ x3(S[3][i]);
323 tmp[3][i] = x3(S[0][i]) ^ x1(S[1][i]) ^ x1(S[2][i]) ^ x2(S[3][i]);
324 }
325
326 memcpy(S, tmp, sizeof(tmp));
327 memset(tmp, 0, sizeof(tmp));
328 }
329
330 /*
331 * |0E 0B 0D 09| |02 03 01 01| |1 0 0 0|
332 * |09 0E 0B 0D|*|01 02 03 01| = |0 1 0 0|
333 * |0D 09 0E 0B| |01 01 02 03| |0 0 1 0|
334 * |0B 0D 09 0E| |03 01 01 02| |0 0 0 1|
335 *
336 */
inv_mix_columns(uint8_t S[4][4])337 static void inv_mix_columns(uint8_t S[4][4])
338 {
339 uint8_t tmp[4][4];
340 int i;
341
342 /* i-th column */
343 for (i = 0; i < 4; i++) {
344 tmp[0][i] = xe(S[0][i]) ^ xb(S[1][i]) ^ xd(S[2][i]) ^ x9(S[3][i]);
345 tmp[1][i] = x9(S[0][i]) ^ xe(S[1][i]) ^ xb(S[2][i]) ^ xd(S[3][i]);
346 tmp[2][i] = xd(S[0][i]) ^ x9(S[1][i]) ^ xe(S[2][i]) ^ xb(S[3][i]);
347 tmp[3][i] = xb(S[0][i]) ^ xd(S[1][i]) ^ x9(S[2][i]) ^ xe(S[3][i]);
348 }
349
350 memcpy(S, tmp, sizeof(tmp));
351 memset(tmp, 0, sizeof(tmp));
352 }
353
354 #ifdef CRYPTO_INFO
print_state(const uint8_t S[4][4])355 static void print_state(const uint8_t S[4][4])
356 {
357 int i;
358 for (i = 0; i < 4; i++) {
359 printf("%02x %02x %02x %02x\n", S[i][0], S[i][1], S[i][2], S[i][3]);
360 }
361 printf("\n");
362 }
363 #endif
364
aes_encrypt(const AES_KEY * key,const uint8_t in[16],uint8_t out[16])365 void aes_encrypt(const AES_KEY *key, const uint8_t in[16], uint8_t out[16])
366 {
367 uint8_t state[4][4];
368 size_t i;
369
370 /* fill state columns */
371 for (i = 0; i < 4; i++) {
372 state[0][i] = *in++;
373 state[1][i] = *in++;
374 state[2][i] = *in++;
375 state[3][i] = *in++;
376 }
377
378 /* Sitial add round key */
379 add_round_key(state, key->rk);
380
381 /* first n-1 rounds */
382 for (i = 1; i < key->rounds; i++) {
383 sub_bytes(state);
384 shift_rows(state);
385 mix_columns(state);
386 add_round_key(state, key->rk + 4*i);
387 }
388
389 /* last round withtmp mix columns */
390 sub_bytes(state);
391 shift_rows(state);
392 add_round_key(state, key->rk + 4*i);
393
394 /* tmpput state columns */
395 for (i = 0; i < 4; i++) {
396 *out++ = state[0][i];
397 *out++ = state[1][i];
398 *out++ = state[2][i];
399 *out++ = state[3][i];
400 }
401
402 memset(state, 0, sizeof(state));
403 }
404
aes_decrypt(const AES_KEY * aes_key,const uint8_t in[16],uint8_t out[16])405 void aes_decrypt(const AES_KEY *aes_key, const uint8_t in[16], uint8_t out[16])
406 {
407 uint8_t state[4][4];
408 size_t i;
409
410 /* fill state columns */
411 for (i = 0; i < 4; i++) {
412 state[0][i] = *in++;
413 state[1][i] = *in++;
414 state[2][i] = *in++;
415 state[3][i] = *in++;
416 }
417
418 /* Sitial add round key */
419 add_round_key(state, aes_key->rk);
420
421 /* first n-1 rounds */
422 for (i = 1; i < aes_key->rounds; i++) {
423 inv_shift_rows(state);
424 inv_sub_bytes(state);
425 add_round_key(state, aes_key->rk + 4*i);
426 inv_mix_columns(state);
427 }
428
429 /* last round withtmp mix columns */
430 inv_shift_rows(state);
431 inv_sub_bytes(state);
432 add_round_key(state, aes_key->rk + 4*i);
433
434 /* tmpput state columns */
435 for (i = 0; i < 4; i++) {
436 *out++ = state[0][i];
437 *out++ = state[1][i];
438 *out++ = state[2][i];
439 *out++ = state[3][i];
440 }
441
442 memset(state, 0, sizeof(state));
443 }
444