Revision dd025f25 libavutil/aes.c

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libavutil/aes.c
23 23
#include "common.h"
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#include "aes.h"
25 25

  
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typedef union {
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    uint64_t u64[2];
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    uint32_t u32[4];
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    uint8_t u8x4[4][4];
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    uint8_t u8[16];
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} av_aes_block;
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typedef struct AVAES{
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    // Note: round_key[16] is accessed in the init code, but this only
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    // overwrites state, which does not matter (see also r7471).
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    uint8_t round_key[15][4][4];
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    uint8_t state[2][4][4];
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    av_aes_block round_key[15];
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    av_aes_block state[2];
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    int rounds;
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}AVAES;
33 40

  
......
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static uint32_t dec_multbl[4][256];
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#endif
49 56

  
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static inline void addkey(uint64_t dst[2], const uint64_t src[2], const uint64_t round_key[2]){
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    dst[0] = src[0] ^ round_key[0];
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    dst[1] = src[1] ^ round_key[1];
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static inline void addkey(av_aes_block *dst, const av_aes_block *src, const av_aes_block *round_key){
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    dst->u64[0] = src->u64[0] ^ round_key->u64[0];
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    dst->u64[1] = src->u64[1] ^ round_key->u64[1];
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}
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static void subshift(uint8_t s0[2][16], int s, const uint8_t *box){
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    uint8_t (*s1)[16]= s0[0] - s;
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    uint8_t (*s3)[16]= s0[0] + s;
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    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]];
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    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]];
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    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]];
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    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]];
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static void subshift(av_aes_block s0[2], int s, const uint8_t *box){
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    av_aes_block *s1= (av_aes_block *)(s0[0].u8 - s);
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    av_aes_block *s3= (av_aes_block *)(s0[0].u8 + s);
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    s0[0].u8[0]=box[s0[1].u8[ 0]]; s0[0].u8[ 4]=box[s0[1].u8[ 4]]; s0[0].u8[ 8]=box[s0[1].u8[ 8]]; s0[0].u8[12]=box[s0[1].u8[12]];
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    s1[0].u8[3]=box[s1[1].u8[ 7]]; s1[0].u8[ 7]=box[s1[1].u8[11]]; s1[0].u8[11]=box[s1[1].u8[15]]; s1[0].u8[15]=box[s1[1].u8[ 3]];
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    s0[0].u8[2]=box[s0[1].u8[10]]; s0[0].u8[10]=box[s0[1].u8[ 2]]; s0[0].u8[ 6]=box[s0[1].u8[14]]; s0[0].u8[14]=box[s0[1].u8[ 6]];
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    s3[0].u8[1]=box[s3[1].u8[13]]; s3[0].u8[13]=box[s3[1].u8[ 9]]; s3[0].u8[ 9]=box[s3[1].u8[ 5]]; s3[0].u8[ 5]=box[s3[1].u8[ 1]];
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}
63 70

  
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static inline int mix_core(uint32_t multbl[][256], int a, int b, int c, int d){
......
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#endif
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}
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static inline void mix(uint8_t state[2][4][4], uint32_t multbl[][256], int s1, int s3){
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    ((uint32_t *)(state))[0] = mix_core(multbl, state[1][0][0], state[1][s1  ][1], state[1][2][2], state[1][s3  ][3]);
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    ((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]);
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    ((uint32_t *)(state))[2] = mix_core(multbl, state[1][2][0], state[1][s3  ][1], state[1][0][2], state[1][s1  ][3]);
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    ((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]);
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static inline void mix(av_aes_block state[2], uint32_t multbl[][256], int s1, int s3){
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    state[0].u32[0] = mix_core(multbl, state[1].u8x4[0][0], state[1].u8x4[s1  ][1], state[1].u8x4[2][2], state[1].u8x4[s3  ][3]);
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    state[0].u32[1] = mix_core(multbl, state[1].u8x4[1][0], state[1].u8x4[s3-1][1], state[1].u8x4[3][2], state[1].u8x4[s1-1][3]);
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    state[0].u32[2] = mix_core(multbl, state[1].u8x4[2][0], state[1].u8x4[s3  ][1], state[1].u8x4[0][2], state[1].u8x4[s1  ][3]);
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    state[0].u32[3] = mix_core(multbl, state[1].u8x4[3][0], state[1].u8x4[s1-1][1], state[1].u8x4[1][2], state[1].u8x4[s3-1][3]);
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}
79 86

  
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static inline void crypt(AVAES *a, int s, const uint8_t *sbox, uint32_t multbl[][256]){
......
82 89

  
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    for(r=a->rounds-1; r>0; r--){
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        mix(a->state, multbl, 3-s, 1+s);
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        addkey(a->state[1], a->state[0], a->round_key[r]);
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        addkey(&a->state[1], &a->state[0], &a->round_key[r]);
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    }
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    subshift(a->state[0][0], s, sbox);
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    subshift(&a->state[0], s, sbox);
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}
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void av_aes_crypt(AVAES *a, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt){
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void av_aes_crypt(AVAES *a, uint8_t *dst_, const uint8_t *src_, int count, uint8_t *iv_, int decrypt){
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    av_aes_block *dst = (av_aes_block *)dst_;
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    const av_aes_block *src = (const av_aes_block *)src_;
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    av_aes_block *iv = (av_aes_block *)iv_;
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    while(count--){
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        addkey(a->state[1], src, a->round_key[a->rounds]);
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        addkey(&a->state[1], src, &a->round_key[a->rounds]);
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        if(decrypt) {
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            crypt(a, 0, inv_sbox, dec_multbl);
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            if(iv){
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                addkey(a->state[0], a->state[0], iv);
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                addkey(&a->state[0], &a->state[0], iv);
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                memcpy(iv, src, 16);
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            }
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            addkey(dst, a->state[0], a->round_key[0]);
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            addkey(dst, &a->state[0], &a->round_key[0]);
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        }else{
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            if(iv) addkey(a->state[1], a->state[1], iv);
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            if(iv) addkey(&a->state[1], &a->state[1], iv);
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            crypt(a, 2,     sbox, enc_multbl);
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            addkey(dst, a->state[0], a->round_key[0]);
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            addkey(dst, &a->state[0], &a->round_key[0]);
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            if(iv) memcpy(iv, dst, 16);
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        }
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        src+=16;
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        dst+=16;
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        src++;
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        dst++;
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    }
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}
110 120

  
......
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    memcpy(tk, key, KC*4);
159 169

  
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    for(t= 0; t < (rounds+1)*16;) {
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        memcpy(a->round_key[0][0]+t, tk, KC*4);
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        memcpy(a->round_key[0].u8+t, tk, KC*4);
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        t+= KC*4;
163 173

  
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        for(i = 0; i < 4; i++)
......
175 185

  
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    if(decrypt){
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        for(i=1; i<rounds; i++){
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            uint8_t tmp[3][16];
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            memcpy(tmp[2], a->round_key[i][0], 16);
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            av_aes_block tmp[3];
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            memcpy(&tmp[2], &a->round_key[i], 16);
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            subshift(&tmp[1], 0, sbox);
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            mix(tmp, dec_multbl, 1, 3);
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            memcpy(a->round_key[i][0], tmp[0], 16);
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            memcpy(&a->round_key[i], &tmp[0], 16);
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        }
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    }else{
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        for(i=0; i<(rounds+1)>>1; i++){
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            for(j=0; j<16; j++)
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                FFSWAP(int, a->round_key[i][0][j], a->round_key[rounds-i][0][j]);
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                FFSWAP(int, a->round_key[i].u8[j], a->round_key[rounds-i].u8[j]);
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        }
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    }
190 200

  

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