MD5加密API为某些明文返回错误的哈希值
我正在尝试使用Microsoft加密API来计算MD5哈希值，但是我得到的哈希值不正确：
#include #include #include char* HashMD5(char* data, DWORD *result) { DWORD dwStatus = 0; DWORD cbHash = 16; int i = 0; HCRYPTPROV cryptProv; HCRYPTHASH cryptHash; BYTE hash[16]; char *hex = "01234567879abcdef"; char *strHash = "00000000000000000000000000000000"; if(!CryptAcquireContext(&cryptProv, NULL, MS_DEF_PROV, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) { dwStatus = GetLastError(); printf("CryptAcquireContext failed: %d\n", dwStatus); *result = dwStatus; return NULL; } if(!CryptCreateHash(cryptProv, CALG_MD5, 0, 0, &cryptHash)) { dwStatus = GetLastError(); printf("CryptCreateHash failed: %d\n", dwStatus); CryptReleaseContext(cryptProv, 0); *result = dwStatus; return NULL; } if(!CryptHashData(cryptHash, (BYTE*)data, strlen(data), 0)) { dwStatus = GetLastError(); printf("CryptHashData failed: %d\n", dwStatus); CryptReleaseContext(cryptProv, 0); CryptDestroyHash(cryptHash); *result = dwStatus; return NULL; } if(!CryptGetHashParam(cryptHash, HP_HASHVAL, hash, &cbHash, 0)) { dwStatus = GetLastError(); printf("CryptGetHashParam failed: %d\n", dwStatus); CryptReleaseContext(cryptProv, 0); CryptDestroyHash(cryptHash); *result = dwStatus; return NULL; } for(i = 0; i > 4]; strHash[(i*2)+1] = hex[hash[i] & 0xF]; } CryptReleaseContext(cryptProv, 0); CryptDestroyHash(cryptHash); return strHash; } int main(int argc, char **argv) { DWORD result = 0; char* hash; if(argc != 2) { printf("Usage: crypto.exe \n"); return 0; } hash = HashMD5(argv[1], &result); if(result == 0) { printf("Hash of '%s' is: %s\n", argv[1], hash); } else { printf("Failed! Result: %d\n", result); } return result; } 代码执行正常，没有打印错误消息，但返回的哈希值对于某些明文不正确：
$ ./crypto.exe test Hash of 'test' is: 078e6abc4621c373b9cd4d832627a4e6 $ ./crypto.exe StackOverflow Hash of 'StackOverflow' is: 84c7cb17766b446e5d4084d8ebd87e82
后者是正确的，但前者应该是098f6bcd4621d373cade4e832627b4f6 。
我究竟做错了什么？
char *hex = "01234567879abcdef";
你在那一行有一个错误。
它应该是：
char *hex = "0123456789abcdef";
strHash[i*2] = hex[hash[i] >> 4]; strHash[(i*2)+1] = hex[hash[i] & 0xF];
strHash指向一个字符串文字。 字符串文字是不可修改的。 修改字符串文字是未定义的行为。