密码学---hash函数（SHA-256）的C++实现

  1 //SHA-256
  2 /*理解算法最重要，最好自己动手实现试试看，可以使用MFC写一个简单的交互界面*/
  3 
  4 #include <iostream> 
  5 #include <cstdio>
  6 #include <cstdlib>
  7 
  8 using namespace std;
  9 
 10 #define SHA256_ROTL(a,b) (((a>>(32-b))&(0x7fffffff>>(31-b)))|(a<<b))
 11 #define SHA256_SR(a,b) ((a>>b)&(0x7fffffff>>(b-1)))
 12 #define SHA256_Ch(x,y,z) ((x&y)^((~x)&z))
 13 #define SHA256_Maj(x,y,z) ((x&y)^(x&z)^(y&z))
 14 #define SHA256_E0(x) (SHA256_ROTL(x,30)^SHA256_ROTL(x,19)^SHA256_ROTL(x,10))
 15 #define SHA256_E1(x) (SHA256_ROTL(x,26)^SHA256_ROTL(x,21)^SHA256_ROTL(x,7))
 16 #define SHA256_O0(x) (SHA256_ROTL(x,25)^SHA256_ROTL(x,14)^SHA256_SR(x,3))
 17 #define SHA256_O1(x) (SHA256_ROTL(x,15)^SHA256_ROTL(x,13)^SHA256_SR(x,10))
 18 char* StrSHA256(const char* str, long long length, char* sha256){
 19     char *pp, *ppend;
 20     long l, i, W[64], T1, T2, A, B, C, D, E, F, G, H, H0, H1, H2, H3, H4, H5, H6, H7;
 21     H0 = 0x6a09e667, H1 = 0xbb67ae85, H2 = 0x3c6ef372, H3 = 0xa54ff53a;
 22     H4 = 0x510e527f, H5 = 0x9b05688c, H6 = 0x1f83d9ab, H7 = 0x5be0cd19;
 23     long K[64] = {
 24         0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
 25         0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
 26         0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
 27         0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
 28         0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
 29         0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
 30         0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
 31         0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
 32     };
 33     l = length + ((length % 64 > 56) ? (128 - length % 64) : (64 - length % 64));
 34     if (!(pp = (char*)malloc((unsigned long)l))) return 0;
 35     for (i = 0; i < length; pp[i + 3 - 2 * (i % 4)] = str[i], i++);
 36     for (pp[i + 3 - 2 * (i % 4)] = 128, i++; i < l; pp[i + 3 - 2 * (i % 4)] = 0, i++);
 37     *((long*)(pp + l - 4)) = length << 3;
 38     *((long*)(pp + l - 8)) = length >> 29;
 39     for (ppend = pp + l; pp < ppend; pp += 64){
 40         for (i = 0; i < 16; W[i] = ((long*)pp)[i], i++);
 41         for (i = 16; i < 64; W[i] = (SHA256_O1(W[i - 2]) + W[i - 7] + SHA256_O0(W[i - 15]) + W[i - 16]), i++);
 42         A = H0, B = H1, C = H2, D = H3, E = H4, F = H5, G = H6, H = H7;
 43         for (i = 0; i < 64; i++){
 44             T1 = H + SHA256_E1(E) + SHA256_Ch(E, F, G) + K[i] + W[i];
 45             T2 = SHA256_E0(A) + SHA256_Maj(A, B, C);
 46             H = G, G = F, F = E, E = D + T1, D = C, C = B, B = A, A = T1 + T2;
 47         }
 48         H0 += A, H1 += B, H2 += C, H3 += D, H4 += E, H5 += F, H6 += G, H7 += H;
 49     }
 50     free(pp - l);
 51     sprintf(sha256, "%08X%08X%08X%08X%08X%08X%08X%08X", H0, H1, H2, H3, H4, H5, H6, H7);
 52     return sha256;
 53 }
 54 char* FileSHA256(const char* file, char* sha256){
 55 
 56     FILE* fh;
 57     char* addlp, T[64];
 58     long addlsize, j, W[64], T1, T2, A, B, C, D, E, F, G, H, H0, H1, H2, H3, H4, H5, H6, H7;
 59     long long length, i, cpys;
 60     void *pp, *ppend;
 61     H0 = 0x6a09e667, H1 = 0xbb67ae85, H2 = 0x3c6ef372, H3 = 0xa54ff53a;
 62     H4 = 0x510e527f, H5 = 0x9b05688c, H6 = 0x1f83d9ab, H7 = 0x5be0cd19;
 63     long K[64] = {
 64         0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
 65         0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
 66         0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
 67         0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
 68         0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
 69         0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
 70         0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
 71         0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
 72     };
 73     fh = fopen(file, "rb");
 74     fseek(fh, 0, SEEK_END);
 75     length = _ftelli64(fh);
 76     addlsize = (56 - length % 64 > 0) ? (64) : (128);
 77     if (!(addlp = (char*)malloc(addlsize))) return 0;
 78     cpys = ((length - (56 - length % 64)) > 0) ? (length - length % 64) : (0);
 79     j = (long)(length - cpys);
 80     if (!(pp = (char*)malloc(j))) return 0;
 81     fseek(fh, -j, SEEK_END);
 82     fread(pp, 1, j, fh);
 83     for (i = 0; i < j; addlp[i + 3 - 2 * (i % 4)] = ((char*)pp)[i], i++);
 84     free(pp);
 85     for (addlp[i + 3 - 2 * (i % 4)] = 128, i++; i < addlsize; addlp[i + 3 - 2 * (i % 4)] = 0, i++);
 86     *((long*)(addlp + addlsize - 4)) = length << 3;
 87     *((long*)(addlp + addlsize - 8)) = length >> 29;
 88     for (rewind(fh); 64 == fread(W, 1, 64, fh);){
 89         for (i = 0; i < 64; T[i + 3 - 2 * (i % 4)] = ((char*)W)[i], i++);
 90         for (i = 0; i < 16; W[i] = ((long*)T)[i], i++);
 91         for (i = 16; i < 64; W[i] = (SHA256_O1(W[i - 2]) + W[i - 7] + SHA256_O0(W[i - 15]) + W[i - 16]), i++);
 92         A = H0, B = H1, C = H2, D = H3, E = H4, F = H5, G = H6, H = H7;
 93         for (i = 0; i < 64; i++){
 94             T1 = H + SHA256_E1(E) + SHA256_Ch(E, F, G) + K[i] + W[i];
 95             T2 = SHA256_E0(A) + SHA256_Maj(A, B, C);
 96             H = G, G = F, F = E, E = D + T1, D = C, C = B, B = A, A = T1 + T2;
 97         }
 98         H0 += A, H1 += B, H2 += C, H3 += D, H4 += E, H5 += F, H6 += G, H7 += H;
 99     }
100     for (pp = addlp, ppend = addlp + addlsize; pp < ppend; pp = (long*)pp + 16){
101         for (i = 0; i < 16; W[i] = ((long*)pp)[i], i++);
102         for (i = 16; i < 64; W[i] = (SHA256_O1(W[i - 2]) + W[i - 7] + SHA256_O0(W[i - 15]) + W[i - 16]), i++);
103         A = H0, B = H1, C = H2, D = H3, E = H4, F = H5, G = H6, H = H7;
104         for (i = 0; i < 64; i++){
105             T1 = H + SHA256_E1(E) + SHA256_Ch(E, F, G) + K[i] + W[i];
106             T2 = SHA256_E0(A) + SHA256_Maj(A, B, C);
107             H = G, G = F, F = E, E = D + T1, D = C, C = B, B = A, A = T1 + T2;
108         }
109         H0 += A, H1 += B, H2 += C, H3 += D, H4 += E, H5 += F, H6 += G, H7 += H;
110     }
111     free(addlp); fclose(fh);
112     sprintf(sha256, "%08X%08X%08X%08X%08X%08X%08X%08X", H0, H1, H2, H3, H4, H5, H6, H7);
113     return sha256;
114 }
115 
116 char* StrSHA256(const char* str, long long length, char* sha256);
117 
118 int main(void){
119     char text[256];
120     cout<<"请输入原文：\n" ;
121     while(cin>>text) 
122     {
123         cout<<"请输入原文：\n" ;
124         char sha256[256];
125         StrSHA256(text,sizeof(text)-1,sha256);  // sizeof()包含了末尾的终止符‘\0‘故 -1
126         cout<<"执行SHA-256算法后的结果如下：\n";
127         puts(sha256);
128         
129     }
130     
131     system("pause");
132     return 0;
133 }