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  1. /*
  2. * copyright (c) 2007 Michael Niedermayer <michaelni@gmx.at> and Reimar Doeffinger
  3. *
  4. * This file is part of FFmpeg.
  5. *
  6. * FFmpeg is free software; you can redistribute it and/or
  7. * modify it under the terms of the GNU Lesser General Public
  8. * License as published by the Free Software Foundation; either
  9. * version 2.1 of the License, or (at your option) any later version.
  10. *
  11. * FFmpeg is distributed in the hope that it will be useful,
  12. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14. * Lesser General Public License for more details.
  15. *
  16. * You should have received a copy of the GNU Lesser General Public
  17. * License along with FFmpeg; if not, write to the Free Software
  18. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19. */
  20. #include "common.h"
  21. #include "log.h"
  22. #include "aes.h"
  23. typedef struct AVAES{
  24. uint8_t round_key[15][4][4];
  25. uint8_t state[4][4];
  26. int rounds;
  27. }AVAES;
  28. static const uint8_t rcon[10] = {
  29. 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36
  30. };
  31. static uint8_t sbox[256];
  32. static uint8_t inv_sbox[256];
  33. #ifdef CONFIG_SMALL
  34. static uint32_t enc_multbl[1][256];
  35. static uint32_t dec_multbl[1][256];
  36. #else
  37. static uint32_t enc_multbl[4][256];
  38. static uint32_t dec_multbl[4][256];
  39. #endif
  40. static inline void addkey(uint64_t state[2], uint64_t round_key[2]){
  41. state[0] ^= round_key[0];
  42. state[1] ^= round_key[1];
  43. }
  44. #define SUBSHIFT0(s, box) s[0]=box[s[ 0]]; s[ 4]=box[s[ 4]]; s[ 8]=box[s[ 8]]; s[12]=box[s[12]];
  45. #define SUBSHIFT1(s, box) t=s[0]; s[0]=box[s[ 4]]; s[ 4]=box[s[ 8]]; s[ 8]=box[s[12]]; s[12]=box[t];
  46. #define SUBSHIFT2(s, box) t=s[0]; s[0]=box[s[ 8]]; s[ 8]=box[ t]; t=s[ 4]; s[ 4]=box[s[12]]; s[12]=box[t];
  47. #define SUBSHIFT3(s, box) t=s[0]; s[0]=box[s[12]]; s[12]=box[s[ 8]]; s[ 8]=box[s[ 4]]; s[ 4]=box[t];
  48. #define SUBSHIFT1x(s) t=s[0]; s[0]=s[ 4]; s[ 4]=s[ 8]; s[ 8]=s[12]; s[12]=t;
  49. #define SUBSHIFT2x(s) t=s[0]; s[0]=s[ 8]; s[ 8]= t; t=s[ 4]; s[ 4]=s[12]; s[12]=t;
  50. #define SUBSHIFT3x(s) t=s[0]; s[0]=s[12]; s[12]=s[ 8]; s[ 8]=s[ 4]; s[ 4]=t;
  51. #define ROT(x,s) ((x<<s)|(x>>(32-s)))
  52. static inline void mix(uint8_t state[4][4], uint32_t multbl[4][256]){
  53. int i;
  54. for(i=0; i<4; i++)
  55. #ifdef CONFIG_SMALL
  56. ((uint32_t *)(state))[i] = multbl[0][state[i][0]] ^ ROT(multbl[0][state[i][1]], 8)
  57. ^ROT(multbl[0][state[i][2]],16) ^ ROT(multbl[0][state[i][3]],24);
  58. #else
  59. ((uint32_t *)(state))[i] = multbl[0][state[i][0]] ^ multbl[1][state[i][1]]
  60. ^multbl[2][state[i][2]] ^ multbl[3][state[i][3]];
  61. #endif
  62. }
  63. static inline void crypt(AVAES *a, int s, uint8_t *sbox, uint32_t *multbl){
  64. int t, r;
  65. for(r=a->rounds; r>1; r--){
  66. addkey(a->state, a->round_key[r]);
  67. SUBSHIFT3x((a->state[0]+1+s))
  68. SUBSHIFT2x((a->state[0]+2))
  69. SUBSHIFT1x((a->state[0]+3-s))
  70. mix(a->state, multbl);
  71. }
  72. addkey(a->state, a->round_key[1]);
  73. SUBSHIFT0((a->state[0]+0 ), sbox)
  74. SUBSHIFT3((a->state[0]+1+s), sbox)
  75. SUBSHIFT2((a->state[0]+2 ), sbox)
  76. SUBSHIFT1((a->state[0]+3-s), sbox)
  77. addkey(a->state, a->round_key[0]);
  78. }
  79. void av_aes_decrypt(AVAES *a){
  80. crypt(a, 0, inv_sbox, dec_multbl);
  81. }
  82. void av_aes_encrypt(AVAES *a){
  83. crypt(a, 2, sbox, enc_multbl);
  84. }
  85. static init_multbl2(uint8_t tbl[1024], int c[4], uint8_t *log8, uint8_t *alog8, uint8_t *sbox){
  86. int i;
  87. for(i=0; i<1024; i++){
  88. int x= sbox[i/4];
  89. if(x) tbl[i]= alog8[ log8[x] + log8[c[i&3]] ];
  90. }
  91. }
  92. // this is based on the reference AES code by Paulo Barreto and Vincent Rijmen
  93. AVAES *av_aes_init(uint8_t *key, int key_bits, int decrypt) {
  94. AVAES *a;
  95. int i, j, t, rconpointer = 0;
  96. uint8_t tk[8][4];
  97. int KC= key_bits/32;
  98. int rounds= KC + 6;
  99. uint8_t log8[256];
  100. uint8_t alog8[512];
  101. if(!sbox[255]){
  102. j=1;
  103. for(i=0; i<255; i++){
  104. alog8[i]=
  105. alog8[i+255]= j;
  106. log8[j]= i;
  107. j^= j+j;
  108. if(j>255) j^= 0x11B;
  109. }
  110. for(i=0; i<256; i++){
  111. j= i ? alog8[255-log8[i]] : 0;
  112. j ^= (j<<1) ^ (j<<2) ^ (j<<3) ^ (j<<4);
  113. j = (j ^ (j>>8) ^ 99) & 255;
  114. inv_sbox[j]= i;
  115. sbox [i]= j;
  116. // av_log(NULL, AV_LOG_ERROR, "%d, ", log8[i]);
  117. }
  118. init_multbl2(dec_multbl[0], (int[4]){0xe, 0x9, 0xd, 0xb}, log8, alog8, inv_sbox);
  119. #ifndef CONFIG_SMALL
  120. init_multbl2(dec_multbl[1], (int[4]){0xb, 0xe, 0x9, 0xd}, log8, alog8, inv_sbox);
  121. init_multbl2(dec_multbl[2], (int[4]){0xd, 0xb, 0xe, 0x9}, log8, alog8, inv_sbox);
  122. init_multbl2(dec_multbl[3], (int[4]){0x9, 0xd, 0xb, 0xe}, log8, alog8, inv_sbox);
  123. #endif
  124. init_multbl2(enc_multbl[0], (int[4]){0x2, 0x1, 0x1, 0x3}, log8, alog8, sbox);
  125. #ifndef CONFIG_SMALL
  126. init_multbl2(enc_multbl[1], (int[4]){0x3, 0x2, 0x1, 0x1}, log8, alog8, sbox);
  127. init_multbl2(enc_multbl[2], (int[4]){0x1, 0x3, 0x2, 0x1}, log8, alog8, sbox);
  128. init_multbl2(enc_multbl[3], (int[4]){0x1, 0x1, 0x3, 0x2}, log8, alog8, sbox);
  129. #endif
  130. }
  131. if(key_bits!=128 && key_bits!=192 && key_bits!=256)
  132. return NULL;
  133. a= av_malloc(sizeof(AVAES));
  134. a->rounds= rounds;
  135. memcpy(tk, key, KC*4);
  136. for(t= 0; t < (rounds+1)*4;) {
  137. memcpy(a->round_key[0][t], tk, KC*4);
  138. t+= KC;
  139. for(i = 0; i < 4; i++)
  140. tk[0][i] ^= sbox[tk[KC-1][(i+1)&3]];
  141. tk[0][0] ^= rcon[rconpointer++];
  142. for(j = 1; j < KC; j++){
  143. if(KC != 8 || j != KC/2)
  144. for(i = 0; i < 4; i++) tk[j][i] ^= tk[j-1][i];
  145. else
  146. for(i = 0; i < 4; i++) tk[j][i] ^= sbox[tk[j-1][i]];
  147. }
  148. }
  149. if(decrypt){
  150. for(i=1; i<rounds; i++){
  151. for(j=0; j<16; j++)
  152. a->round_key[i][0][j]= sbox[a->round_key[i][0][j]];
  153. mix(a->round_key[i], dec_multbl);
  154. }
  155. }else{
  156. for(i=0; i<(rounds+1)/2; i++){
  157. for(j=0; j<16; j++)
  158. FFSWAP(int, a->round_key[i][0][j], a->round_key[rounds-i][0][j]);
  159. }
  160. }
  161. return a;
  162. }
  163. #ifdef TEST
  164. int main(){
  165. int i,j,k;
  166. AVAES *ae= av_aes_init("PI=3.141592654..", 128, 0);
  167. AVAES *ad= av_aes_init("PI=3.141592654..", 128, 1);
  168. uint8_t zero[16]= {0};
  169. uint8_t pt[16]= {0x6a, 0x84, 0x86, 0x7c, 0xd7, 0x7e, 0x12, 0xad, 0x07, 0xea, 0x1b, 0xe8, 0x95, 0xc5, 0x3f, 0xa3};
  170. uint8_t ct[16]= {0x73, 0x22, 0x81, 0xc0, 0xa0, 0xaa, 0xb8, 0xf7, 0xa5, 0x4a, 0x0c, 0x67, 0xa0, 0xc4, 0x5e, 0xcf};
  171. AVAES *b= av_aes_init(zero, 128, 1);
  172. /* uint8_t key[16]= {0x42, 0x78, 0xb8, 0x40, 0xfb, 0x44, 0xaa, 0xa7, 0x57, 0xc1, 0xbf, 0x04, 0xac, 0xbe, 0x1a, 0x3e};
  173. uint8_t IV[16] = {0x57, 0xf0, 0x2a, 0x5c, 0x53, 0x39, 0xda, 0xeb, 0x0a, 0x29, 0x08, 0xa0, 0x6a, 0xc6, 0x39, 0x3f};
  174. uint8_t pt[16] = {0x3c, 0x88, 0x8b, 0xbb, 0xb1, 0xa8, 0xeb, 0x9f, 0x3e, 0x9b, 0x87, 0xac, 0xaa, 0xd9, 0x86, 0xc4};
  175. // 66e2f7071c83083b8a557971918850e5
  176. uint8_t ct[16] = {0x47, 0x9c, 0x89, 0xec, 0x14, 0xbc, 0x98, 0x99, 0x4e, 0x62, 0xb2, 0xc7, 0x05, 0xb5, 0x0, 0x14e};
  177. // 175bd7832e7e60a1e92aac568a861eb7*/
  178. uint8_t ckey[16]= {0x10, 0xa5, 0x88, 0x69, 0xd7, 0x4b, 0xe5, 0xa3, 0x74, 0xcf, 0x86, 0x7c, 0xfb, 0x47, 0x38, 0x59};
  179. uint8_t cct[16] = {0x6d, 0x25, 0x1e, 0x69, 0x44, 0xb0, 0x51, 0xe0, 0x4e, 0xaa, 0x6f, 0xb4, 0xdb, 0xf7, 0x84, 0x65};
  180. AVAES *c= av_aes_init(ckey, 128, 1);
  181. av_log_level= AV_LOG_DEBUG;
  182. memcpy(b->state, ct, 16);
  183. av_aes_decrypt(b);
  184. for(j=0; j<16; j++)
  185. if(pt[j] != b->state[0][j]){
  186. av_log(NULL, AV_LOG_ERROR, "%d %02X %02X\n", j, pt[j], b->state[0][j]);
  187. }
  188. memcpy(c->state, cct, 16);
  189. av_aes_decrypt(c);
  190. for(j=0; j<16; j++)
  191. if(zero[j] != c->state[0][j]){
  192. av_log(NULL, AV_LOG_ERROR, "%d %02X %02X\n", j, zero[j], c->state[0][j]);
  193. }
  194. for(i=0; i<10000; i++){
  195. for(j=0; j<16; j++){
  196. pt[j]= random();
  197. }
  198. memcpy(ae->state, pt, 16);
  199. {START_TIMER
  200. av_aes_encrypt(ae);
  201. if(!(i&(i-1)))
  202. av_log(NULL, AV_LOG_ERROR, "%02X %02X %02X %02X\n", ae->state[0][0], ae->state[1][1], ae->state[2][2], ae->state[3][3]);
  203. memcpy(ad->state, ae->state, 16);
  204. av_aes_decrypt(ad);
  205. STOP_TIMER("aes")}
  206. for(j=0; j<16; j++){
  207. if(pt[j] != ad->state[0][j]){
  208. av_log(NULL, AV_LOG_ERROR, "%d %d %02X %02X\n", i,j, pt[j], ad->state[0][j]);
  209. }
  210. }
  211. }
  212. return 0;
  213. }
  214. #endif