Libav
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00001 /* 00002 * copyright (c) 2007 Michael Niedermayer <michaelni@gmx.at> 00003 * 00004 * some optimization ideas from aes128.c by Reimar Doeffinger 00005 * 00006 * This file is part of FFmpeg. 00007 * 00008 * FFmpeg is free software; you can redistribute it and/or 00009 * modify it under the terms of the GNU Lesser General Public 00010 * License as published by the Free Software Foundation; either 00011 * version 2.1 of the License, or (at your option) any later version. 00012 * 00013 * FFmpeg is distributed in the hope that it will be useful, 00014 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00016 * Lesser General Public License for more details. 00017 * 00018 * You should have received a copy of the GNU Lesser General Public 00019 * License along with FFmpeg; if not, write to the Free Software 00020 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00021 */ 00022 00023 #include "common.h" 00024 #include "aes.h" 00025 00026 typedef struct AVAES{ 00027 // Note: round_key[16] is accessed in the init code, but this only 00028 // overwrites state, which does not matter (see also r7471). 00029 uint8_t round_key[15][4][4]; 00030 uint8_t state[2][4][4]; 00031 int rounds; 00032 }AVAES; 00033 00034 const int av_aes_size= sizeof(AVAES); 00035 00036 static const uint8_t rcon[10] = { 00037 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 00038 }; 00039 00040 static uint8_t sbox[256]; 00041 static uint8_t inv_sbox[256]; 00042 #if CONFIG_SMALL 00043 static uint32_t enc_multbl[1][256]; 00044 static uint32_t dec_multbl[1][256]; 00045 #else 00046 static uint32_t enc_multbl[4][256]; 00047 static uint32_t dec_multbl[4][256]; 00048 #endif 00049 00050 static inline void addkey(uint64_t dst[2], const uint64_t src[2], const uint64_t round_key[2]){ 00051 dst[0] = src[0] ^ round_key[0]; 00052 dst[1] = src[1] ^ round_key[1]; 00053 } 00054 00055 static void subshift(uint8_t s0[2][16], int s, const uint8_t *box){ 00056 uint8_t (*s1)[16]= s0[0] - s; 00057 uint8_t (*s3)[16]= s0[0] + s; 00058 s0[0][0]=box[s0[1][ 0]]; s0[0][ 4]=box[s0[1][ 4]]; s0[0][ 8]=box[s0[1][ 8]]; s0[0][12]=box[s0[1][12]]; 00059 s1[0][3]=box[s1[1][ 7]]; s1[0][ 7]=box[s1[1][11]]; s1[0][11]=box[s1[1][15]]; s1[0][15]=box[s1[1][ 3]]; 00060 s0[0][2]=box[s0[1][10]]; s0[0][10]=box[s0[1][ 2]]; s0[0][ 6]=box[s0[1][14]]; s0[0][14]=box[s0[1][ 6]]; 00061 s3[0][1]=box[s3[1][13]]; s3[0][13]=box[s3[1][ 9]]; s3[0][ 9]=box[s3[1][ 5]]; s3[0][ 5]=box[s3[1][ 1]]; 00062 } 00063 00064 static inline int mix_core(uint32_t multbl[4][256], int a, int b, int c, int d){ 00065 #if CONFIG_SMALL 00066 #define ROT(x,s) ((x<<s)|(x>>(32-s))) 00067 return multbl[0][a] ^ ROT(multbl[0][b], 8) ^ ROT(multbl[0][c], 16) ^ ROT(multbl[0][d], 24); 00068 #else 00069 return multbl[0][a] ^ multbl[1][b] ^ multbl[2][c] ^ multbl[3][d]; 00070 #endif 00071 } 00072 00073 static inline void mix(uint8_t state[2][4][4], uint32_t multbl[4][256], int s1, int s3){ 00074 ((uint32_t *)(state))[0] = mix_core(multbl, state[1][0][0], state[1][s1 ][1], state[1][2][2], state[1][s3 ][3]); 00075 ((uint32_t *)(state))[1] = mix_core(multbl, state[1][1][0], state[1][s3-1][1], state[1][3][2], state[1][s1-1][3]); 00076 ((uint32_t *)(state))[2] = mix_core(multbl, state[1][2][0], state[1][s3 ][1], state[1][0][2], state[1][s1 ][3]); 00077 ((uint32_t *)(state))[3] = mix_core(multbl, state[1][3][0], state[1][s1-1][1], state[1][1][2], state[1][s3-1][3]); 00078 } 00079 00080 static inline void crypt(AVAES *a, int s, const uint8_t *sbox, const uint32_t *multbl){ 00081 int r; 00082 00083 for(r=a->rounds-1; r>0; r--){ 00084 mix(a->state, multbl, 3-s, 1+s); 00085 addkey(a->state[1], a->state[0], a->round_key[r]); 00086 } 00087 subshift(a->state[0][0], s, sbox); 00088 } 00089 00090 void av_aes_crypt(AVAES *a, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt){ 00091 while(count--){ 00092 addkey(a->state[1], src, a->round_key[a->rounds]); 00093 if(decrypt) { 00094 crypt(a, 0, inv_sbox, dec_multbl); 00095 if(iv){ 00096 addkey(a->state[0], a->state[0], iv); 00097 memcpy(iv, src, 16); 00098 } 00099 addkey(dst, a->state[0], a->round_key[0]); 00100 }else{ 00101 if(iv) addkey(a->state[1], a->state[1], iv); 00102 crypt(a, 2, sbox, enc_multbl); 00103 addkey(dst, a->state[0], a->round_key[0]); 00104 if(iv) memcpy(iv, dst, 16); 00105 } 00106 src+=16; 00107 dst+=16; 00108 } 00109 } 00110 00111 static void init_multbl2(uint8_t tbl[1024], const int c[4], const uint8_t *log8, const uint8_t *alog8, const uint8_t *sbox){ 00112 int i, j; 00113 for(i=0; i<1024; i++){ 00114 int x= sbox[i>>2]; 00115 if(x) tbl[i]= alog8[ log8[x] + log8[c[i&3]] ]; 00116 } 00117 #if !CONFIG_SMALL 00118 for(j=256; j<1024; j++) 00119 for(i=0; i<4; i++) 00120 tbl[4*j+i]= tbl[4*j + ((i-1)&3) - 1024]; 00121 #endif 00122 } 00123 00124 // this is based on the reference AES code by Paulo Barreto and Vincent Rijmen 00125 int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt) { 00126 int i, j, t, rconpointer = 0; 00127 uint8_t tk[8][4]; 00128 int KC= key_bits>>5; 00129 int rounds= KC + 6; 00130 uint8_t log8[256]; 00131 uint8_t alog8[512]; 00132 00133 if(!enc_multbl[0][sizeof(enc_multbl)/sizeof(enc_multbl[0][0])-1]){ 00134 j=1; 00135 for(i=0; i<255; i++){ 00136 alog8[i]= 00137 alog8[i+255]= j; 00138 log8[j]= i; 00139 j^= j+j; 00140 if(j>255) j^= 0x11B; 00141 } 00142 for(i=0; i<256; i++){ 00143 j= i ? alog8[255-log8[i]] : 0; 00144 j ^= (j<<1) ^ (j<<2) ^ (j<<3) ^ (j<<4); 00145 j = (j ^ (j>>8) ^ 99) & 255; 00146 inv_sbox[j]= i; 00147 sbox [i]= j; 00148 } 00149 init_multbl2(dec_multbl[0], (const int[4]){0xe, 0x9, 0xd, 0xb}, log8, alog8, inv_sbox); 00150 init_multbl2(enc_multbl[0], (const int[4]){0x2, 0x1, 0x1, 0x3}, log8, alog8, sbox); 00151 } 00152 00153 if(key_bits!=128 && key_bits!=192 && key_bits!=256) 00154 return -1; 00155 00156 a->rounds= rounds; 00157 00158 memcpy(tk, key, KC*4); 00159 00160 for(t= 0; t < (rounds+1)*16;) { 00161 memcpy(a->round_key[0][0]+t, tk, KC*4); 00162 t+= KC*4; 00163 00164 for(i = 0; i < 4; i++) 00165 tk[0][i] ^= sbox[tk[KC-1][(i+1)&3]]; 00166 tk[0][0] ^= rcon[rconpointer++]; 00167 00168 for(j = 1; j < KC; j++){ 00169 if(KC != 8 || j != KC>>1) 00170 for(i = 0; i < 4; i++) tk[j][i] ^= tk[j-1][i]; 00171 else 00172 for(i = 0; i < 4; i++) tk[j][i] ^= sbox[tk[j-1][i]]; 00173 } 00174 } 00175 00176 if(decrypt){ 00177 for(i=1; i<rounds; i++){ 00178 uint8_t tmp[3][16]; 00179 memcpy(tmp[2], a->round_key[i][0], 16); 00180 subshift(tmp[1], 0, sbox); 00181 mix(tmp, dec_multbl, 1, 3); 00182 memcpy(a->round_key[i][0], tmp[0], 16); 00183 } 00184 }else{ 00185 for(i=0; i<(rounds+1)>>1; i++){ 00186 for(j=0; j<16; j++) 00187 FFSWAP(int, a->round_key[i][0][j], a->round_key[rounds-i][0][j]); 00188 } 00189 } 00190 00191 return 0; 00192 } 00193 00194 #ifdef TEST 00195 #include "lfg.h" 00196 #include "log.h" 00197 00198 int main(void){ 00199 int i,j; 00200 AVAES ae, ad, b; 00201 uint8_t rkey[2][16]= { 00202 {0}, 00203 {0x10, 0xa5, 0x88, 0x69, 0xd7, 0x4b, 0xe5, 0xa3, 0x74, 0xcf, 0x86, 0x7c, 0xfb, 0x47, 0x38, 0x59}}; 00204 uint8_t pt[16], rpt[2][16]= { 00205 {0x6a, 0x84, 0x86, 0x7c, 0xd7, 0x7e, 0x12, 0xad, 0x07, 0xea, 0x1b, 0xe8, 0x95, 0xc5, 0x3f, 0xa3}, 00206 {0}}; 00207 uint8_t rct[2][16]= { 00208 {0x73, 0x22, 0x81, 0xc0, 0xa0, 0xaa, 0xb8, 0xf7, 0xa5, 0x4a, 0x0c, 0x67, 0xa0, 0xc4, 0x5e, 0xcf}, 00209 {0x6d, 0x25, 0x1e, 0x69, 0x44, 0xb0, 0x51, 0xe0, 0x4e, 0xaa, 0x6f, 0xb4, 0xdb, 0xf7, 0x84, 0x65}}; 00210 uint8_t temp[16]; 00211 AVLFG prng; 00212 00213 av_aes_init(&ae, "PI=3.141592654..", 128, 0); 00214 av_aes_init(&ad, "PI=3.141592654..", 128, 1); 00215 av_log_set_level(AV_LOG_DEBUG); 00216 av_lfg_init(&prng, 1); 00217 00218 for(i=0; i<2; i++){ 00219 av_aes_init(&b, rkey[i], 128, 1); 00220 av_aes_crypt(&b, temp, rct[i], 1, NULL, 1); 00221 for(j=0; j<16; j++) 00222 if(rpt[i][j] != temp[j]) 00223 av_log(NULL, AV_LOG_ERROR, "%d %02X %02X\n", j, rpt[i][j], temp[j]); 00224 } 00225 00226 for(i=0; i<10000; i++){ 00227 for(j=0; j<16; j++){ 00228 pt[j] = av_lfg_get(&prng); 00229 } 00230 {START_TIMER 00231 av_aes_crypt(&ae, temp, pt, 1, NULL, 0); 00232 if(!(i&(i-1))) 00233 av_log(NULL, AV_LOG_ERROR, "%02X %02X %02X %02X\n", temp[0], temp[5], temp[10], temp[15]); 00234 av_aes_crypt(&ad, temp, temp, 1, NULL, 1); 00235 STOP_TIMER("aes")} 00236 for(j=0; j<16; j++){ 00237 if(pt[j] != temp[j]){ 00238 av_log(NULL, AV_LOG_ERROR, "%d %d %02X %02X\n", i,j, pt[j], temp[j]); 00239 } 00240 } 00241 } 00242 return 0; 00243 } 00244 #endif