aes.c

AES加密C源码

#include "stdio.h"
   
typedef unsigned char  u1byte;   
typedef unsigned long  u4byte;   
   
#define LARGE_TABLES    
   
u1byte  pow_tab[256];   
u1byte  log_tab[256];   
u1byte  sbx_tab[256];   
u1byte  isb_tab[256];   
u4byte  rco_tab[ 10];   
u4byte  ft_tab[4][256];   
u4byte  it_tab[4][256];   
   
#ifdef  LARGE_TABLES    
  u4byte  fl_tab[4][256];   
  u4byte  il_tab[4][256];   
#endif    
   
u4byte  tab_gen = 0;   
   
u4byte  k_len;   
u4byte  e_key[60];   
u4byte  d_key[60];   
   
#define ff_mult(a,b)    (a && b ? pow_tab[(log_tab[a] + log_tab[b]) % 255] : 0)    
#define byte(x,n)       ((u1byte)((x)>>(8*n)))    
   
#define f_rn(bo, bi, n, k) bo[n] =  ft_tab[0][byte(bi[n],0)] ^ft_tab[1][byte(bi[(n + 1) & 3],1)] ^ft_tab[2][byte(bi[(n + 2) & 3],2)] ^ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)   
   
#define i_rn(bo, bi, n, k) bo[n] =  it_tab[0][byte(bi[n],0)] ^it_tab[1][byte(bi[(n + 3) & 3],1)] ^it_tab[2][byte(bi[(n + 2) & 3],2)] ^it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)   
   
#define rotr(x,n)  (((x) >> ((int)(n))) | ((x) << (32 -(int)(n))))    
   
#define rotl(x,n)  (((x) << ((int)(n))) | ((x) >> (32 -(int)(n))))    
   
   
#ifdef LARGE_TABLES    
   
#define ls_box(x) ( fl_tab[0][byte(x, 0)] ^fl_tab[1][byte(x, 1)] ^fl_tab[2][byte(x, 2)] ^fl_tab[3][byte(x, 3)] )   
   
#define f_rl(bo, bi, n, k) bo[n] =  fl_tab[0][byte(bi[n],0)] ^fl_tab[1][byte(bi[(n + 1) & 3],1)] ^fl_tab[2][byte(bi[(n + 2) & 3],2)] ^fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)   
   
#define i_rl(bo, bi, n, k) bo[n] =  il_tab[0][byte(bi[n],0)] ^il_tab[1][byte(bi[(n + 3) & 3],1)] ^il_tab[2][byte(bi[(n + 2) & 3],2)] ^il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)   
   
#else    
   
#define ls_box(x) ((u4byte)sbx_tab[byte(x, 0)] <<  0) ^((u4byte)sbx_tab[byte(x, 1)] <<  8) ^((u4byte)sbx_tab[byte(x, 2)] << 16) ^((u4byte)sbx_tab[byte(x, 3)] << 24)   
   
#define f_rl(bo, bi, n, k) bo[n] = (u4byte)sbx_tab[byte(bi[n],0)] ^rotl(((u4byte)sbx_tab[byte(bi[(n + 1) & 3],1)]),  8) ^rotl(((u4byte)sbx_tab[byte(bi[(n + 2) & 3],2)]), 16) ^rotl(((u4byte)sbx_tab[byte(bi[(n + 3) & 3],3)]), 24) ^ *(k + n)   
   
#define i_rl(bo, bi, n, k) bo[n] = (u4byte)isb_tab[byte(bi[n],0)] ^rotl(((u4byte)isb_tab[byte(bi[(n + 3) & 3],1)]),  8) ^rotl(((u4byte)isb_tab[byte(bi[(n + 2) & 3],2)]), 16) ^rotl(((u4byte)isb_tab[byte(bi[(n + 1) & 3],3)]), 24) ^ *(k + n)   
   
#endif    
   
void gen_tabs(void)   
{   u4byte  i, t;   
    u1byte  p, q;
   
    for(i = 0,p = 1; i < 256; ++i)   
    {   
        pow_tab[i] = (u1byte)p; log_tab[p] = (u1byte)i;   
   
        p = p ^ (p << 1) ^ (p & 0x80 ? 0x01b : 0);   
    }   
   
    log_tab[1] = 0; p = 1;   
   
    for(i = 0; i < 10; ++i)   
    {   
        rco_tab[i] = p;    
   
        p = (p << 1) ^ (p & 0x80 ? 0x1b : 0);   
    }   
   
    for(i = 0; i < 256; ++i)   
    {      
        p = (i ? pow_tab[255 - log_tab[i]] : 0); q = p;    
        q = (q >> 7) | (q << 1); p ^= q;    
        q = (q >> 7) | (q << 1); p ^= q;    
        q = (q >> 7) | (q << 1); p ^= q;    
        q = (q >> 7) | (q << 1); p ^= q ^ 0x63;    
        sbx_tab[i] = p; isb_tab[p] = (u1byte)i;   
    }   
   
    for(i = 0; i < 256; ++i)   
    {   
        p = sbx_tab[i];    
   
#ifdef  LARGE_TABLES            
           
        t = p; fl_tab[0][i] = t;   
        fl_tab[1][i] = rotl(t,  8);   
        fl_tab[2][i] = rotl(t, 16);   
        fl_tab[3][i] = rotl(t, 24);   
#endif    
        t = ((u4byte)ff_mult(2, p)) |   
            ((u4byte)p <<  8) |   
            ((u4byte)p << 16) |   
            ((u4byte)ff_mult(3, p) << 24);   
           
        ft_tab[0][i] = t;   
        ft_tab[1][i] = rotl(t,  8);   
        ft_tab[2][i] = rotl(t, 16);   
        ft_tab[3][i] = rotl(t, 24);   
   
        p = isb_tab[i];    
   
#ifdef  LARGE_TABLES            
           
        t = p; il_tab[0][i] = t;    
        il_tab[1][i] = rotl(t,  8);    
        il_tab[2][i] = rotl(t, 16);    
        il_tab[3][i] = rotl(t, 24);   
#endif     
        t = ((u4byte)ff_mult(14, p)) |   
            ((u4byte)ff_mult( 9, p) <<  8) |   
            ((u4byte)ff_mult(13, p) << 16) |   
            ((u4byte)ff_mult(11, p) << 24);   
           
        it_tab[0][i] = t;    
        it_tab[1][i] = rotl(t,  8);    
        it_tab[2][i] = rotl(t, 16);    
        it_tab[3][i] = rotl(t, 24);    
    }   
   
    tab_gen = 1;   
}   
   
#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)    
   
#define imix_col(y,x) u   = star_x(x); v   = star_x(u);w   = star_x(v);t   = w ^ (x);(y)  = u ^ v ^ w;(y) ^= rotr(u ^ t,  8) ^rotr(v ^ t, 16) ^rotr(t,24)   
   

   
#define loop4(i) { t = ls_box(rotr(t,  8)) ^ rco_tab[i];t ^= e_key[4 * i];     e_key[4 * i + 4] = t;t ^= e_key[4 * i + 1]; e_key[4 * i + 5] = t;t ^= e_key[4 * i + 2]; e_key[4 * i + 6] = t;t ^= e_key[4 * i + 3]; e_key[4 * i + 7] = t;}   
   
#define loop6(i) { t = ls_box(rotr(t,  8)) ^ rco_tab[i];t ^= e_key[6 * i];     e_key[6 * i + 6] = t;t ^= e_key[6 * i + 1]; e_key[6 * i + 7] = t;t ^= e_key[6 * i + 2]; e_key[6 * i + 8] = t;t ^= e_key[6 * i + 3]; e_key[6 * i + 9] = t;t ^= e_key[6 * i + 4]; e_key[6 * i + 10] = t;t ^= e_key[6 * i + 5]; e_key[6 * i + 11] = t;}   
   
#define loop8(i) { t = ls_box(rotr(t,  8)) ^ rco_tab[i];t ^= e_key[8 * i];     e_key[8 * i + 8] = t;t ^= e_key[8 * i + 1]; e_key[8 * i + 9] = t;t ^= e_key[8 * i + 2]; e_key[8 * i + 10] = t;t ^= e_key[8 * i + 3]; e_key[8 * i + 11] = t;t  = e_key[8 * i + 4] ^ ls_box(t);e_key[8 * i + 12] = t;t ^= e_key[8 * i + 5]; e_key[8 * i + 13] = t;t ^= e_key[8 * i + 6]; e_key[8 * i + 14] = t;t ^= e_key[8 * i + 7]; e_key[8 * i + 15] = t;}   
   
void set_key(const u4byte in_key[], const u4byte key_len)   
{   u4byte  i, t, u, v, w;   
   
    if(!tab_gen)   
   
        gen_tabs();   
   
    k_len = (key_len + 31) / 32;   
   
    e_key[0] = in_key[0];    
    e_key[1] = in_key[1];   
    e_key[2] = in_key[2];    
    e_key[3] = in_key[3];   
   
    switch(k_len)   
    {   
        case 4: t = e_key[3];   
                for(i = 0; i < 10; ++i)    
                    loop4(i);   
                break;   
   
        case 6: e_key[4] = in_key[4]; t = e_key[5] = in_key[5];   
                for(i = 0; i < 8; ++i)    
                    loop6(i);   
                break;   
   
        case 8: e_key[4] = in_key[4]; e_key[5] = in_key[5];   
                e_key[6] = in_key[6]; t = e_key[7] = in_key[7];   
                for(i = 0; i < 7; ++i)    
                    loop8(i);   
                break;   
    }   
   
    d_key[0] = e_key[0]; d_key[1] = e_key[1];   
    d_key[2] = e_key[2]; d_key[3] = e_key[3];   
   
    for(i = 4; i < 4 * k_len + 24; ++i)   
    {   
        imix_col(d_key[i], e_key[i]);   
    }   
   
       
}   

   
#define f_nround(bo, bi, k) f_rn(bo, bi, 0, k);f_rn(bo, bi, 1, k);f_rn(bo, bi, 2, k);f_rn(bo, bi, 3, k);k += 4   
   
#define f_lround(bo, bi, k) f_rl(bo, bi, 0, k);f_rl(bo, bi, 1, k);f_rl(bo, bi, 2, k);f_rl(bo, bi, 3, k)   
   
void encrypt(const u4byte in_blk[4], u4byte out_blk[4])   
{   u4byte  b0[4], b1[4], *kp;   
   
    b0[0] = in_blk[0] ^ e_key[0]; b0[1] = in_blk[1] ^ e_key[1];   
    b0[2] = in_blk[2] ^ e_key[2]; b0[3] = in_blk[3] ^ e_key[3];   
   
    kp = e_key + 4;   
   
    if(k_len > 6)   
    {   
        f_nround(b1, b0, kp); f_nround(b0, b1, kp);   
    }   
   
    if(k_len > 4)   
    {   
        f_nround(b1, b0, kp); f_nround(b0, b1, kp);   
    }   
   
    f_nround(b1, b0, kp); f_nround(b0, b1, kp);   
    f_nround(b1, b0, kp); f_nround(b0, b1, kp);   
    f_nround(b1, b0, kp); f_nround(b0, b1, kp);   
    f_nround(b1, b0, kp); f_nround(b0, b1, kp);   
    f_nround(b1, b0, kp); f_lround(b0, b1, kp);   
   
    out_blk[0] = b0[0]; out_blk[1] = b0[1];   
    out_blk[2] = b0[2]; out_blk[3] = b0[3];   
}   

   
#define i_nround(bo, bi, k) i_rn(bo, bi, 0, k);i_rn(bo, bi, 1, k);i_rn(bo, bi, 2, k);i_rn(bo, bi, 3, k);k -= 4   
   
#define i_lround(bo, bi, k) i_rl(bo, bi, 0, k);i_rl(bo, bi, 1, k);i_rl(bo, bi, 2, k);i_rl(bo, bi, 3, k)   
   
void decrypt(const u4byte in_blk[4], u4byte out_blk[4])   
{   u4byte  b0[4], b1[4], *kp;   
   
    b0[0] = in_blk[0] ^ e_key[4 * k_len + 24];    
    b0[1] = in_blk[1] ^ e_key[4 * k_len + 25];    
    b0[2] = in_blk[2] ^ e_key[4 * k_len + 26];    
    b0[3] = in_blk[3] ^ e_key[4 * k_len + 27];   
   
    kp = d_key + 4 * (k_len + 5);   
   
    if(k_len > 6)   
    {   
        i_nround(b1, b0, kp); i_nround(b0, b1, kp);   
    }   
   
    if(k_len > 4)   
    {   
        i_nround(b1, b0, kp); i_nround(b0, b1, kp);   
    }   
   
    i_nround(b1, b0, kp); i_nround(b0, b1, kp);   
    i_nround(b1, b0, kp); i_nround(b0, b1, kp);   
    i_nround(b1, b0, kp); i_nround(b0, b1, kp);   
    i_nround(b1, b0, kp); i_nround(b0, b1, kp);   
    i_nround(b1, b0, kp); i_lround(b0, b1, kp);   
   
    out_blk[0] = b0[0]; out_blk[1] = b0[1];   
    out_blk[2] = b0[2]; out_blk[3] = b0[3];   
}   
   
void main()   
{      
    int i;   
    u4byte out_block[4];   
    const u4byte in_key[4] = {0x11111111,0x22222222,0x33333333,0x44444444};   
    const u4byte plain_block[4] = {0x11111112,0x22222223,0x33333334,0x44444445};   
    const u4byte cipher_block[4] = {0x00000001,0x00000002,0x00000003,0x00000004};   
    printf("------------------------------------------------------\n");   
    set_key(in_key, 128);   
    for(i=0;i<4;i++)   
        printf("%x",plain_block[i]);   
    encrypt(plain_block, out_block);   
    printf("\nEncryptions:\n");   
    for(i=0;i<4;i++)   
        printf("%x",out_block[i]);   
    decrypt(out_block, out_block);   
    printf("\nDecryptions:\n");   
    for(i=0;i<4;i++)   
        printf("%x",out_block[i]);   
        printf("\n");  
}