我的C ++应用程序需要计算MD5哈希值。目前，它由OpenSSL完成，我想使用WinAPI - 以避免依赖外部库。
我写了这段代码：
HCRYPTPROV hCryptProv = NULL;
HCRYPTHASH hHash = NULL;
HCRYPTHASH hHexHash = NULL;
HASH HA1;
HASHHEX HA1HEX;
DWORD data = HASHLEN;
// Get a handle to a cryptography provider context.
if(!CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, 0))
{
goto err;
}
// Acquire a hash object handle.
if(!CryptCreateHash(hCryptProv, CALG_MD5, 0, 0, &hHash))
{
goto err;
}
CryptHashData(hHash, (const BYTE *)str, strlen(str), 0);
现在，奇怪的是有时它运行良好，但在其他时候CryptAcquireContext返回NTE_BAD_KEYSET错误，根据MSDN：
密钥容器无法打开。此错误的常见原因是密钥容器不存在。要创建密钥容器，请使用CRYPT_NEWKEYSET标志调用CryptAcquireContext。此错误代码还可以指示拒绝访问现有密钥容器。密钥集创建者可以使用CryptSetProvParam授予对容器的访问权限。
大段引用
现在我的问题是：
如果有人给我很好的建议，我会很感激。 谢谢。
所以，我找到了一个在http://msdn.microsoft.com/en-us/library/aa382380%28VS.85%29.aspx做你想做的事的例子
看看他们的代码，我看到的区别是这一行：
他们的：CryptAcquireContext（＆hCryptProv，NULL，NULL，PROV_RSA_FULL，CRYPT_VERIFYCONTEXT）
你的：CryptAcquireContext（＆hCryptProv，NULL，NULL，PROV_RSA_FULL，0）
所以，阅读那面旗帜，我发现这个信息：
CRYPT_VERIFYCONTEXT：此选项适用于使用临时密钥的应用程序或不需要访问持久私钥的应用程序，例如仅执行散列，加密和数字签名验证的应用程序。只有创建签名或解密消息的应用程序才需要访问私钥。在大多数情况下，应该设置此标志。
http://msdn.microsoft.com/en-us/library/windows/desktop/aa379886%28v=vs.85%29.aspx
因此，您似乎正在尝试访问不需要的信息，并且请求被拒绝。因此，最好的选择是通过包含该标志告诉Windows您不需要该信息。
我喜欢使用PROV_RSA_AES和CRYPT_VERIFYCONTEXT，因为大多数哈希都是支持的。
这是一个工作示例：
#include <Wincrypt.h>
enum HashType
{
HashSha1, HashMd5, HashSha256
};
std::string GetHashText( const void * data, const size_t data_size, HashType hashType )
{
HCRYPTPROV hProv = NULL;
if ( ! CryptAcquireContext( &hProv, NULL, NULL, PROV_RSA_AES, CRYPT_VERIFYCONTEXT ) ) {
return "";
}
BOOL hash_ok = FALSE;
HCRYPTPROV hHash = NULL;
switch ( hashType ) {
case HashSha1 : hash_ok = CryptCreateHash( hProv, CALG_SHA1, 0, 0, &hHash ); break;
case HashMd5 : hash_ok = CryptCreateHash( hProv, CALG_MD5, 0, 0, &hHash ); break;
case HashSha256 : hash_ok = CryptCreateHash( hProv, CALG_SHA_256, 0, 0, &hHash ); break;
}
if ( ! hash_ok ) {
CryptReleaseContext(hProv, 0);
return "";
}
if ( ! CryptHashData( hHash, static_cast<const BYTE *>(data), data_size, 0 ) ) {
CryptDestroyHash(hHash);
CryptReleaseContext(hProv, 0);
return "";
}
DWORD cbHashSize = 0, dwCount = sizeof(DWORD);
if( ! CryptGetHashParam( hHash, HP_HASHSIZE, (BYTE *)&cbHashSize, &dwCount, 0 ) ) {
CryptDestroyHash(hHash);
CryptReleaseContext(hProv, 0);
return "";
}
std::vector<BYTE> buffer( cbHashSize );
if ( ! CryptGetHashParam( hHash, HP_HASHVAL, reinterpret_cast<BYTE*>( &buffer[0] ), &cbHashSize, 0) ) {
CryptDestroyHash(hHash);
CryptReleaseContext(hProv, 0);
return "";
}
std::ostringstream oss;
for ( std::vector<BYTE>::const_iterator iter = buffer.begin(); iter != buffer.end(); ++iter ) {
oss.fill('0');
oss.width(2);
oss << std::hex << static_cast<const int>(*iter);
}
CryptDestroyHash(hHash);
CryptReleaseContext(hProv, 0);
return oss.str();
}
我有这个link
但为了在我这边运行这个功能，我做了一些改动，希望它可能有所帮助
char* HashMD5(char* data, DWORD *result)
{
DWORD dwStatus = 0;
DWORD cbHash = 16;
int i = 0;
HCRYPTPROV cryptProv;
HCRYPTHASH cryptHash;
BYTE hash[16];
char *hex = "0123456789abcdef";
char *strHash;
strHash = (char*)malloc(500);
memset(strHash, '\0', 500);
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 < cbHash; i++)
{
strHash[i * 2] = hex[hash[i] >> 4];
strHash[(i * 2) + 1] = hex[hash[i] & 0xF];
}
CryptReleaseContext(cryptProv, 0);
CryptDestroyHash(cryptHash);
return strHash;
}
可以创建以下“MD5.h”文件，并且可以使用简单的代码。
main.cpp中
#include "md5.h"
int main()
{
MD5 md5;
puts( md5.digestString( "HELLO THERE I AM MD5!" ) ) ;
// print the digest for a binary file on disk.
puts( md5.digestFile( "C:\\WINDOWS\\notepad.exe" ) ) ;
return 0;
}
MD5.h
#ifndef MD5_H
#define MD5_H
#include <stdio.h>
#include <string.h>
#pragma region MD5 defines
// Constants for MD5Transform routine.
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21
static unsigned char PADDING[64] = {
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
// F, G, H and I are basic MD5 functions.
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))
// ROTATE_LEFT rotates x left n bits.
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
// FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
// Rotation is separate from addition to prevent recomputation.
#define FF(a, b, c, d, x, s, ac) { \
(a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define GG(a, b, c, d, x, s, ac) { \
(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define HH(a, b, c, d, x, s, ac) { \
(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define II(a, b, c, d, x, s, ac) { \
(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#pragma endregion
typedef unsigned char BYTE;
// POINTER defines a generic pointer type
typedef unsigned char *POINTER;
// UINT2 defines a two byte word
typedef unsigned short int UINT2;
// UINT4 defines a four byte word
typedef unsigned long int UINT4;
// convenient object that wraps
// the C-functions for use in C++ only
class MD5
{
private:
struct __context_t {
UINT4 state[4]; /* state (ABCD) */
UINT4 count[2]; /* number of bits, modulo 2^64 (lsb first) */
unsigned char buffer[64]; /* input buffer */
} context;
#pragma region static helper functions
// The core of the MD5 algorithm is here.
// MD5 basic transformation. Transforms state based on block.
static void MD5Transform(UINT4 state[4], unsigned char block[64])
{
UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
Decode(x, block, 64);
/* Round 1 */
FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
/* Round 2 */
GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */
GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
/* Round 3 */
HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */
HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */
/* Round 4 */
II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
// Zeroize sensitive information.
memset((POINTER)x, 0, sizeof(x));
}
// Encodes input (UINT4) into output (unsigned char). Assumes len is
// a multiple of 4.
static void Encode(unsigned char *output, UINT4 *input, unsigned int len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (unsigned char)(input[i] & 0xff);
output[j + 1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j + 2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j + 3] = (unsigned char)((input[i] >> 24) & 0xff);
}
}
// Decodes input (unsigned char) into output (UINT4). Assumes len is
// a multiple of 4.
static void Decode(UINT4 *output, unsigned char *input, unsigned int len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((UINT4)input[j]) | (((UINT4)input[j + 1]) << 8) |
(((UINT4)input[j + 2]) << 16) | (((UINT4)input[j + 3]) << 24);
}
#pragma endregion
public:
// MAIN FUNCTIONS
MD5()
{
Init();
}
// MD5 initialization. Begins an MD5 operation, writing a new context.
void Init()
{
context.count[0] = context.count[1] = 0;
// Load magic initialization constants.
context.state[0] = 0x67452301;
context.state[1] = 0xefcdab89;
context.state[2] = 0x98badcfe;
context.state[3] = 0x10325476;
}
// MD5 block update operation. Continues an MD5 message-digest
// operation, processing another message block, and updating the
// context.
void Update(
unsigned char *input, // input block
unsigned int inputLen) // length of input block
{
unsigned int i, index, partLen;
// Compute number of bytes mod 64
index = (unsigned int)((context.count[0] >> 3) & 0x3F);
// Update number of bits
if ((context.count[0] += ((UINT4)inputLen << 3))
< ((UINT4)inputLen << 3))
context.count[1]++;
context.count[1] += ((UINT4)inputLen >> 29);
partLen = 64 - index;
// Transform as many times as possible.
if (inputLen >= partLen) {
memcpy((POINTER)&context.buffer[index], (POINTER)input, partLen);
MD5Transform(context.state, context.buffer);
for (i = partLen; i + 63 < inputLen; i += 64)
MD5Transform(context.state, &input[i]);
index = 0;
}
else
i = 0;
/* Buffer remaining input */
memcpy((POINTER)&context.buffer[index], (POINTER)&input[i], inputLen - i);
}
// MD5 finalization. Ends an MD5 message-digest operation, writing the
// the message digest and zeroizing the context.
// Writes to digestRaw
void Final()
{
unsigned char bits[8];
unsigned int index, padLen;
// Save number of bits
Encode(bits, context.count, 8);
// Pad out to 56 mod 64.
index = (unsigned int)((context.count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
Update(PADDING, padLen);
// Append length (before padding)
Update(bits, 8);
// Store state in digest
Encode(digestRaw, context.state, 16);
// Zeroize sensitive information.
memset((POINTER)&context, 0, sizeof(context));
writeToString();
}
/// Buffer must be 32+1 (nul) = 33 chars long at least
void writeToString()
{
int pos;
for (pos = 0; pos < 16; pos++)
sprintf(digestChars + (pos * 2), "%02x", digestRaw[pos]);
}
public:
// an MD5 digest is a 16-byte number (32 hex digits)
BYTE digestRaw[16];
// This version of the digest is actually
// a "printf'd" version of the digest.
char digestChars[33];
/// Load a file from disk and digest it
// Digests a file and returns the result.
char* digestFile(char *filename)
{
Init();
FILE *file;
int len;
unsigned char buffer[1024];
if ((file = fopen(filename, "rb")) == NULL)
printf("%s can't be opened\n", filename);
else
{
while (len = fread(buffer, 1, 1024, file))
Update(buffer, len);
Final();
fclose(file);
}
return digestChars;
}
/// Digests a byte-array already in memory
char* digestMemory(BYTE *memchunk, int len)
{
Init();
Update(memchunk, len);
Final();
return digestChars;
}
// Digests a string and prints the result.
char* digestString(char *string)
{
Init();
Update((unsigned char*)string, strlen(string));
Final();
return digestChars;
}
};
#endif