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@Lilacy 2017-03-05T23:20:43.000000Z 字数 7965 阅读 1049 
  1. #include <stdio.h>
  2. #include <stdlib.h>
  3. #include <stdint.h>
  4. //Addition in GF(2^8)
  5. uint8_t gadd(uint8_t a, uint8_t b) {
  6.     return a^b;
  7. }
  8. //Subtraction in GF(2^8)
  9. uint8_t gsub(uint8_t a, uint8_t b) {
  10.     return a^b;
  11. }
  12. //Multiplication in GF(2^8)
  13. uint8_t gmult(uint8_t a, uint8_t b) {
  14.     uint8_t p = 0, i = 0, hbs = 0;
  15.     for (i = 0; i < 8; i++) {
  16.         if (b & 1) {
  17.             p ^= a;
  18.         }
  19.         hbs = a & 0x80;
  20.         a <<= 1;
  21.         if (hbs) a ^= 0x1b; // 0000 0001 0001 1011
  22.         b >>= 1;
  23.     }
  24.     return (uint8_t)p;
  25. }
  26. //Addition of 4 byte words
  27. void coef_add(uint8_t a[], uint8_t b[], uint8_t d[]) {
  28.     d[0] = a[0]^b[0];
  29.     d[1] = a[1]^b[1];
  30.     d[2] = a[2]^b[2];
  31.     d[3] = a[3]^b[3];
  32. }
  33. //Multiplication of 4 byte words,m(x) = x4+1
  34. void coef_mult(uint8_t *a, uint8_t *b, uint8_t *d) {
  35.     d[0] = gmult(a[0],b[0])^gmult(a[3],b[1])^gmult(a[2],b[2])^gmult(a[1],b[3]);
  36.     d[1] = gmult(a[1],b[0])^gmult(a[0],b[1])^gmult(a[3],b[2])^gmult(a[2],b[3]);
  37.     d[2] = gmult(a[2],b[0])^gmult(a[1],b[1])^gmult(a[0],b[2])^gmult(a[3],b[3]);
  38.     d[3] = gmult(a[3],b[0])^gmult(a[2],b[1])^gmult(a[1],b[2])^gmult(a[0],b[3]);
  39. }
  40. //The cipher Key.
  41. int K;
  42. //Number of columns (32-bit words) comprising the State. For this standard, Nb = 4.
  43. int Nb = 4;
  44. //Number of 32-bit words comprising the Cipher Key. For this standard, Nk = 4, 6, or 8.
  45. int Nk;
  46. //Number of rounds, which is a function of  Nk  and  Nb (which is fixed). For this standard, Nr = 10, 12, or 14.
  47. int Nr;
  48. //S-box transformation table
  49. static uint8_t s_box[256] = {
  50.     // 0     1     2     3     4     5     6     7     8     9     a     b     c     d     e     f
  51.     0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, // 0
  52.     0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, // 1
  53.     0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, // 2
  54.     0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, // 3
  55.     0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, // 4
  56.     0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, // 5
  57.     0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, // 6
  58.     0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, // 7
  59.     0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, // 8
  60.     0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, // 9
  61.     0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, // a
  62.     0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, // b
  63.     0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, // c
  64.     0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, // d
  65.     0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, // e
  66.     0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16};// f
  67. //Inverse S-box transformation table
  68. static uint8_t inv_s_box[256] = {
  69.     // 0     1     2     3     4     5     6     7     8     9     a     b     c     d     e     f
  70.     0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, // 0
  71.     0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, // 1
  72.     0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, // 2
  73.     0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25, // 3
  74.     0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, // 4
  75.     0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84, // 5
  76.     0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06, // 6
  77.     0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b, // 7
  78.     0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73, // 8
  79.     0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e, // 9
  80.     0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, // a
  81.     0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4, // b
  82.     0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, // c
  83.     0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, // d
  84.     0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, // e
  85.     0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d};// f
  86. //Generates the round constant Rcon[i]
  87. uint8_t R[] = {0x02, 0x00, 0x00, 0x00};
  88. uint8_t * Rcon(uint8_t i) {
  89.     if (i == 1) {
  90.         R[0] = 0x01; // x^(1-1) = x^0 = 1
  91.     } else if (i > 1) {
  92.         R[0] = 0x02;
  93.         i--;
  94.         while (i-1 > 0) {
  95.             R[0] = gmult(R[0], 0x02);
  96.             i--;
  97.         }
  98.     }
  99.     return R;
  100. }
  101. void add_round_key(uint8_t *state, uint8_t *w, uint8_t r) {
  102.     uint8_t c;
  103.     for (c = 0; c < Nb; c++) {
  104.         state[Nb*0+c] = state[Nb*0+c]^w[4*Nb*r+4*c+0];   //debug, so it works for Nb !=4
  105.         state[Nb*1+c] = state[Nb*1+c]^w[4*Nb*r+4*c+1];
  106.         state[Nb*2+c] = state[Nb*2+c]^w[4*Nb*r+4*c+2];
  107.         state[Nb*3+c] = state[Nb*3+c]^w[4*Nb*r+4*c+3];
  108.     }
  109. }
  110. void mix_columns(uint8_t *state) {
  111.     uint8_t a[] = {0x02, 0x01, 0x01, 0x03}; // a(x) = {02} + {01}x + {01}x2 + {03}x3
  112.     uint8_t i, j, col[4], res[4];
  113.     for (j = 0; j < Nb; j++) {
  114.         for (i = 0; i < 4; i++) {
  115.             col[i] = state[Nb*i+j];
  116.         }
  117.         coef_mult(a, col, res);
  118.         for (i = 0; i < 4; i++) {
  119.             state[Nb*i+j] = res[i];
  120.         }
  121.     }
  122. }
  123. void inv_mix_columns(uint8_t *state) {
  124.     uint8_t a[] = {0x0e, 0x09, 0x0d, 0x0b}; // a(x) = {0e} + {09}x + {0d}x2 + {0b}x3
  125.     uint8_t i, j, col[4], res[4];
  126.     for (j = 0; j < Nb; j++) {
  127.         for (i = 0; i < 4; i++) {
  128.             col[i] = state[Nb*i+j];
  129.         }
  130.         coef_mult(a, col, res);
  131.         for (i = 0; i < 4; i++) {
  132.             state[Nb*i+j] = res[i];
  133.         }
  134.     }
  135. }
  136. void shift_rows(uint8_t *state) {
  137.     uint8_t i, k, s, tmp;
  138.     for (i = 1; i < 4; i++) {
  139.         // shift(1,4)=1; shift(2,4)=2; shift(3,4)=3
  140.         // shift(r, 4) = r;
  141.         s = 0;
  142.         while (s < i) {
  143.             tmp = state[Nb*i+0];
  145.             for (k = 1; k < Nb; k++) {
  146.                 state[Nb*i+k-1] = state[Nb*i+k];
  147.             }
  148.             state[Nb*i+Nb-1] = tmp;
  149.             s++;
  150.         }
  151.     }
  152. }
  153. void inv_shift_rows(uint8_t *state) {
  154.     uint8_t i, k, s, tmp;
  155.     for (i = 1; i < 4; i++) {
  156.         s = 0;
  157.         while (s < i) {
  158.             tmp = state[Nb*i+Nb-1];
  159.             for (k = Nb-1; k > 0; k--) {
  160.                 state[Nb*i+k] = state[Nb*i+k-1];
  161.             }
  162.             state[Nb*i+0] = tmp;
  163.             s++;
  164.         }
  165.     }
  166. }
  167. void sub_bytes(uint8_t *state) {
  168.     uint8_t i, j;
  169.     uint8_t row, col;
  170.     for (i = 0; i < 4; i++) {
  171.         for (j = 0; j < Nb; j++) {
  172.             row = (state[Nb*i+j] & 0xf0) >> 4;
  173.             col = state[Nb*i+j] & 0x0f;
  174.             state[Nb*i+j] = s_box[16*row+col];
  175.         }
  176.     }
  177. }
  178. void inv_sub_bytes(uint8_t *state) {
  179.     uint8_t i, j;
  180.     uint8_t row, col;
  181.     for (i = 0; i < 4; i++) {
  182.         for (j = 0; j < Nb; j++) {
  183.             row = (state[Nb*i+j] & 0xf0) >> 4;
  184.             col = state[Nb*i+j] & 0x0f;
  185.             state[Nb*i+j] = inv_s_box[16*row+col];
  186.         }
  187.     }
  188. }
  189. void sub_word(uint8_t *w) {
  190.     uint8_t i;
  191.     for (i = 0; i < 4; i++) {
  192.         w[i] = s_box[16*((w[i] & 0xf0) >> 4) + (w[i] & 0x0f)];
  193.     }
  194. }
  195. void rot_word(uint8_t *w) {
  196.     uint8_t tmp;
  197.     uint8_t i;
  198.     tmp = w[0];
  199.     for (i = 0; i < 3; i++) {
  200.         w[i] = w[i+1];
  201.     }
  202.     w[3] = tmp;
  203. }
  204. void key_expansion(uint8_t *key, uint8_t *w) {
  205.     uint8_t tmp[4];
  206.     uint8_t i, j;
  207.     uint8_t len = Nb*(Nr+1);
  208.     for (i = 0; i < Nk; i++) {
  209.         w[4*i+0] = key[4*i+0];
  210.         w[4*i+1] = key[4*i+1];
  211.         w[4*i+2] = key[4*i+2];
  212.         w[4*i+3] = key[4*i+3];
  213.     }
  214.     for (i = Nk; i < len; i++) {
  215.         tmp[0] = w[4*(i-1)+0];
  216.         tmp[1] = w[4*(i-1)+1];
  217.         tmp[2] = w[4*(i-1)+2];
  218.         tmp[3] = w[4*(i-1)+3];
  219.         if (i%Nk == 0) {
  220.             rot_word(tmp);
  221.             sub_word(tmp);
  222.             coef_add(tmp, Rcon(i/Nk), tmp);
  223.         } else if (Nk > 6 && i%Nk == 4) {
  224.             sub_word(tmp);
  225.         }
  226.         w[4*i+0] = w[4*(i-Nk)+0]^tmp[0];
  227.         w[4*i+1] = w[4*(i-Nk)+1]^tmp[1];
  228.         w[4*i+2] = w[4*(i-Nk)+2]^tmp[2];
  229.         w[4*i+3] = w[4*(i-Nk)+3]^tmp[3];
  230.     }
  231. }
  232. void cipher(uint8_t *in, uint8_t *out, uint8_t *w) {
  233.     uint8_t state[4*Nb];
  234.     uint8_t r, i, j;
  235.     for (i = 0; i < 4; i++) {
  236.         for (j = 0; j < Nb; j++) {
  237.             state[Nb*i+j] = in[i+4*j];
  238.         }
  239.     }
  240.     add_round_key(state, w, 0);
  241.     for (r = 1; r < Nr; r++) {
  242.         sub_bytes(state);
  243.         shift_rows(state);
  244.         mix_columns(state);
  245.         add_round_key(state, w, r);
  246.     }
  247.     sub_bytes(state);
  248.     shift_rows(state);
  249.     add_round_key(state, w, Nr);
  250.     for (i = 0; i < 4; i++) {
  251.         for (j = 0; j < Nb; j++) {
  252.             out[i+4*j] = state[Nb*i+j];
  253.         }
  254.     }
  255. }
  256. void inv_cipher(uint8_t *in, uint8_t *out, uint8_t *w) {
  257.     uint8_t state[4*Nb];
  258.     uint8_t r, i, j;
  259.     for (i = 0; i < 4; i++) {
  260.         for (j = 0; j < Nb; j++) {
  261.             state[Nb*i+j] = in[i+4*j];
  262.         }
  263.     }
  264.     add_round_key(state, w, Nr);
  265.     for (r = Nr-1; r >= 1; r--) {
  266.         inv_shift_rows(state);
  267.         inv_sub_bytes(state);
  268.         add_round_key(state, w, r);
  269.         inv_mix_columns(state);
  270.     }
  271.     inv_shift_rows(state);
  272.     inv_sub_bytes(state);
  273.     add_round_key(state, w, 0);
  274.     for (i = 0; i < 4; i++) {
  275.         for (j = 0; j < Nb; j++) {
  276.             out[i+4*j] = state[Nb*i+j];
  277.         }
  278.     }
  279. }
  280. int main(int argc, char *argv[]) {
  281.     uint8_t i;
  282.     uint8_t key[] = {
  283.         0x00, 0x01, 0x02, 0x03,
  284.         0x04, 0x05, 0x06, 0x07,
  285.         0x08, 0x09, 0x0a, 0x0b,
  286.         0x0c, 0x0d, 0x0e, 0x0f,
  287.         0x10, 0x11, 0x12, 0x13,
  288.         0x14, 0x15, 0x16, 0x17,
  289.         0x18, 0x19, 0x1a, 0x1b,
  290.         0x1c, 0x1d, 0x1e, 0x1f};
  291.     uint8_t in[] = {
  292.         0x00, 0x11, 0x22, 0x33,
  293.         0x44, 0x55, 0x66, 0x77,
  294.         0x88, 0x99, 0xaa, 0xbb,
  295.         0xcc, 0xdd, 0xee, 0xff};
  296.     uint8_t out[16]; // 128
  297.     uint8_t *w; // expanded key
  298.     switch (sizeof(key)) {
  299.         default:
  300.         case 16: Nk = 4; Nr = 10; break;
  301.         case 24: Nk = 6; Nr = 12; break;
  302.         case 32: Nk = 8; Nr = 14; break;
  303.     }
  304.     w = malloc(Nb*(Nr+1)*4);
  305.     key_expansion(key, w);
  306.     cipher(in /* in */, out /* out */, w /* expanded key */);
  307.     printf("out:\n");
  308.     for (i = 0; i < 4; i++) {
  309.         printf("%x %x %x %x ", out[4*i+0], out[4*i+1], out[4*i+2], out[4*i+3]);
  310.     }
  311.     printf("\n");
  312.     inv_cipher(out, in, w);
  313.     printf("msg:\n");
  314.     for (i = 0; i < 4; i++) {
  315.         printf("%x %x %x %x ", in[4*i+0], in[4*i+1], in[4*i+2], in[4*i+3]);
  316.     }
  317.     printf("\n");
  318.     exit(0);
  319. }
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