md5

C++实现:

// MD5.h

#ifndef MD5_H
#define MD5_H

#include <string>
#include <fstream>
#include <cstring>

/* Type define */
typedef unsigned char byte;
typedef unsigned int bit32;

using std::string;
using std::ifstream;

/* MD5 declaration. */
class MD5 {
public:
	MD5();
	MD5(const void *input, size_t length);
	MD5(const string &str);
	MD5(ifstream &in);
	void update(const void *input, size_t length);
	void update(const string &str);
	void update(ifstream &in);
	const byte* digest();
	string toString();
	void reset();
private:
	void update(const byte *input, size_t length);
	void final();
	void transform(const byte block[64]);
	void encode(const bit32 *input, byte *output, size_t length);
	void decode(const byte *input, bit32 *output, size_t length);
	string bytesToHexString(const byte *input, size_t length);

	/* class uncopyable */
	MD5(const MD5&);
	MD5& operator=(const MD5&);
private:
	bit32 _state[4];	/* state (ABCD) */
	bit32 _count[2];	/* number of bits, modulo 2^64 (low-order word first) */
	byte _buffer[64];	/* input buffer */
	byte _digest[16];	/* message digest */
	bool _finished;		/* calculate finished ? */

	static const byte PADDING[64];	/* padding for calculate */
	static const char HEX[16];
	static const size_t BUFFER_SIZE = 1024;
};

#endif/*MD5_H*/

MD5.cpp

#include "MD5.h"

using namespace std;

/* 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


/* 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) + ac; 
	(a) = ROTATE_LEFT ((a), (s)); 
	(a) += (b); 
}
#define GG(a, b, c, d, x, s, ac) { 
	(a) += G ((b), (c), (d)) + (x) + ac; 
	(a) = ROTATE_LEFT ((a), (s)); 
	(a) += (b); 
}
#define HH(a, b, c, d, x, s, ac) { 
	(a) += H ((b), (c), (d)) + (x) + ac; 
	(a) = ROTATE_LEFT ((a), (s)); 
	(a) += (b); 
}
#define II(a, b, c, d, x, s, ac) { 
	(a) += I ((b), (c), (d)) + (x) + ac; 
	(a) = ROTATE_LEFT ((a), (s)); 
	(a) += (b); 
}


const byte MD5::PADDING[64] = { 0x80 };
const char MD5::HEX[16] = {
	'0', '1', '2', '3',
	'4', '5', '6', '7',
	'8', '9', 'a', 'b',
	'c', 'd', 'e', 'f'
};

/* Default construct. */
MD5::MD5() {
	reset();
}

/* Construct a MD5 object with a input buffer. */
MD5::MD5(const void *input, size_t length) {
	reset();
	update(input, length);
}

/* Construct a MD5 object with a string. */
MD5::MD5(const string &str) {
	reset();
	update(str);
}

/* Construct a MD5 object with a file. */
MD5::MD5(ifstream &in) {
	reset();
	update(in);
}

/* Return the message-digest */
const byte* MD5::digest() {
	if (!_finished) {
		_finished = true;
		final();
	}
	return _digest;
}

/* Reset the calculate state */
void MD5::reset() {

	_finished = false;
	/* reset number of bits. */
	_count[0] = _count[1] = 0;
	/* Load magic initialization constants. */
	_state[0] = 0x67452301;
	_state[1] = 0xefcdab89;
	_state[2] = 0x98badcfe;
	_state[3] = 0x10325476;
}

/* Updating the context with a input buffer. */
void MD5::update(const void *input, size_t length) {
	update((const byte*)input, length);
}

/* Updating the context with a string. */
void MD5::update(const string &str) {
	update((const byte*)str.c_str(), str.length());
}

/* Updating the context with a file. */
void MD5::update(ifstream &in) {

	if (!in)
		return;

	std::streamsize length;
	char buffer[BUFFER_SIZE];
	while (!in.eof()) {
		in.read(buffer, BUFFER_SIZE);
		length = in.gcount();
		if (length > 0)
			update(buffer, length);
	}
	in.close();
}

/* MD5 block update operation. Continues an MD5 message-digest
operation, processing another message block, and updating the
context.
*/
void MD5::update(const byte *input, size_t length) {

	bit32 i, index, partLen;

	_finished = false;

	/* Compute number of bytes mod 64 */
	index = (bit32)((_count[0] >> 3) & 0x3f);

	/* update number of bits */
	if((_count[0] += ((bit32)length << 3)) < ((bit32)length << 3))
		_count[1]++;
	_count[1] += ((bit32)length >> 29);

	partLen = 64 - index;

	/* transform as many times as possible. */
	if(length >= partLen) {

		memcpy(&_buffer[index], input, partLen);
		transform(_buffer);

		for (i = partLen; i + 63 < length; i += 64)
			transform(&input[i]);
		index = 0;

	} else {
		i = 0;
	}

	/* Buffer remaining input */
	memcpy(&_buffer[index], &input[i], length-i);
}

/* MD5 finalization. Ends an MD5 message-_digest operation, writing the
the message _digest and zeroizing the context.
*/
void MD5::final() {

	byte bits[8];
	bit32 oldState[4];
	bit32 oldCount[2];
	bit32 index, padLen;

	/* Save current state and count. */
	memcpy(oldState, _state, 16);
	memcpy(oldCount, _count, 8);

	/* Save number of bits */
	encode(_count, bits, 8);

	/* Pad out to 56 mod 64. */
	index = (bit32)((_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(_state, _digest, 16);

	/* Restore current state and count. */
	memcpy(_state, oldState, 16);
	memcpy(_count, oldCount, 8);
}

/* MD5 basic transformation. Transforms _state based on block. */
void MD5::transform(const byte block[64]) {

	bit32 a = _state[0], b = _state[1], c = _state[2], d = _state[3], x[16];

	decode(block, x, 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;
}

/* Encodes input (ulong) into output (byte). Assumes length is
a multiple of 4.
*/
void MD5::encode(const bit32 *input, byte *output, size_t length) {

	for(size_t i=0, j=0; j<length; i++, j+=4) {
		output[j]= (byte)(input[i] & 0xff);
		output[j+1] = (byte)((input[i] >> 8) & 0xff);
		output[j+2] = (byte)((input[i] >> 16) & 0xff);
		output[j+3] = (byte)((input[i] >> 24) & 0xff);
	}
}

/* Decodes input (byte) into output (ulong). Assumes length is
a multiple of 4.
*/
void MD5::decode(const byte *input, bit32 *output, size_t length) {

	for(size_t i=0, j=0; j<length; i++, j+=4) {	
		output[i] = ((bit32)input[j]) | (((bit32)input[j+1]) << 8) |
			(((bit32)input[j+2]) << 16) | (((bit32)input[j+3]) << 24);
	}
}

/* Convert byte array to hex string. */
string MD5::bytesToHexString(const byte *input, size_t length) {
	string str;
	str.reserve(length << 1);
	for(size_t i = 0; i < length; i++) {
		int t = input[i];
		int a = t / 16;
		int b = t % 16;
		str.append(1, HEX[a]);
		str.append(1, HEX[b]);
	}
	return str;
}

/* Convert digest to string value */
string MD5::toString() {
	return bytesToHexString(digest(), 16);
}

测试用例:

std::string strOri("Hello World");
string outMD5 = MD5(strOri).toString() ;
std::cout << outMD5.c_str() << std::endl;

//////////////////////////////////

C版本MD5

// MD5.h

#ifndef MD5_H  
#define MD5_H  
   
typedef struct  
{  
    unsigned int count[2];  
    unsigned int state[4];  
    unsigned char buffer[64];     
}MD5_CTX;  
   
                           
#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))  
#define ROTATE_LEFT(x,n) ((x << n) | (x >> (32-n)))  
#define FF(a,b,c,d,x,s,ac)   
          {   
          a += F(b,c,d) + x + ac;   
          a = ROTATE_LEFT(a,s);   
          a += b;   
          }  
#define GG(a,b,c,d,x,s,ac)   
          {   
          a += G(b,c,d) + x + ac;   
          a = ROTATE_LEFT(a,s);   
          a += b;   
          }  
#define HH(a,b,c,d,x,s,ac)   
          {   
          a += H(b,c,d) + x + ac;   
          a = ROTATE_LEFT(a,s);   
          a += b;   
          }  
#define II(a,b,c,d,x,s,ac)   
          {   
          a += I(b,c,d) + x + ac;   
          a = ROTATE_LEFT(a,s);   
          a += b;   
          }                                              
void MD5Init(MD5_CTX *context);  
void MD5Update(MD5_CTX *context,unsigned char *input,unsigned int inputlen);  
void MD5Final(MD5_CTX *context,unsigned char digest[16]);  
void MD5Transform(unsigned int state[4],unsigned char block[64]);  
void MD5Encode(unsigned char *output,unsigned int *input,unsigned int len);  
void MD5Decode(unsigned int *output,unsigned char *input,unsigned int len);

// 额外添加的2个处理函数
void MD5ToString(const unsigned char *_input, char *_output);
void MD5Encryption(const char *_input, int nLen, char *_output); #endif

// MD5.c

#include <memory.h>  
#include "md5.h"  
   
unsigned char PADDING[]={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};  
                           
void MD5Init(MD5_CTX *context)  
{  
     context->count[0] = 0;  
     context->count[1] = 0;  
     context->state[0] = 0x67452301;  
     context->state[1] = 0xEFCDAB89;  
     context->state[2] = 0x98BADCFE;  
     context->state[3] = 0x10325476;  
}
void MD5Update(MD5_CTX *context,unsigned char *input,unsigned int inputlen) { unsigned int i = 0,index = 0,partlen = 0; index = (context->count[0] >> 3) & 0x3F; partlen = 64 - index; context->count[0] += inputlen << 3; if(context->count[0] < (inputlen << 3)) context->count[1]++; context->count[1] += inputlen >> 29; if(inputlen >= partlen) { memcpy(&context->buffer[index],input,partlen); MD5Transform(context->state,context->buffer); for(i = partlen;i+64 <= inputlen;i+=64) MD5Transform(context->state,&input[i]); index = 0; } else { i = 0; } memcpy(&context->buffer[index],&input[i],inputlen-i); }
void MD5Final(MD5_CTX *context,unsigned char digest[16]) { unsigned int index = 0,padlen = 0; unsigned char bits[8]; index = (context->count[0] >> 3) & 0x3F; padlen = (index < 56)?(56-index):(120-index); MD5Encode(bits,context->count,8); MD5Update(context,PADDING,padlen); MD5Update(context,bits,8); MD5Encode(digest,context->state,16); }
void MD5Encode(unsigned char *output,unsigned int *input,unsigned int len) { unsigned int i = 0,j = 0; while(j < len) { output[j] = input[i] & 0xFF; output[j+1] = (input[i] >> 8) & 0xFF; output[j+2] = (input[i] >> 16) & 0xFF; output[j+3] = (input[i] >> 24) & 0xFF; i++; j+=4; } }
void MD5Decode(unsigned int *output,unsigned char *input,unsigned int len) { unsigned int i = 0,j = 0; while(j < len) { output[i] = (input[j]) | (input[j+1] << 8) | (input[j+2] << 16) | (input[j+3] << 24); i++; j+=4; } }
void MD5Transform(unsigned int state[4],unsigned char block[64]) { unsigned int a = state[0]; unsigned int b = state[1]; unsigned int c = state[2]; unsigned int d = state[3]; unsigned int x[64]; MD5Decode(x,block,64); FF(a, b, c, d, x[ 0], 7, 0xd76aa478); /* 1 */ FF(d, a, b, c, x[ 1], 12, 0xe8c7b756); /* 2 */ FF(c, d, a, b, x[ 2], 17, 0x242070db); /* 3 */ FF(b, c, d, a, x[ 3], 22, 0xc1bdceee); /* 4 */ FF(a, b, c, d, x[ 4], 7, 0xf57c0faf); /* 5 */ FF(d, a, b, c, x[ 5], 12, 0x4787c62a); /* 6 */ FF(c, d, a, b, x[ 6], 17, 0xa8304613); /* 7 */ FF(b, c, d, a, x[ 7], 22, 0xfd469501); /* 8 */ FF(a, b, c, d, x[ 8], 7, 0x698098d8); /* 9 */ FF(d, a, b, c, x[ 9], 12, 0x8b44f7af); /* 10 */ FF(c, d, a, b, x[10], 17, 0xffff5bb1); /* 11 */ FF(b, c, d, a, x[11], 22, 0x895cd7be); /* 12 */ FF(a, b, c, d, x[12], 7, 0x6b901122); /* 13 */ FF(d, a, b, c, x[13], 12, 0xfd987193); /* 14 */ FF(c, d, a, b, x[14], 17, 0xa679438e); /* 15 */ FF(b, c, d, a, x[15], 22, 0x49b40821); /* 16 */ /* Round 2 */ GG(a, b, c, d, x[ 1], 5, 0xf61e2562); /* 17 */ GG(d, a, b, c, x[ 6], 9, 0xc040b340); /* 18 */ GG(c, d, a, b, x[11], 14, 0x265e5a51); /* 19 */ GG(b, c, d, a, x[ 0], 20, 0xe9b6c7aa); /* 20 */ GG(a, b, c, d, x[ 5], 5, 0xd62f105d); /* 21 */ GG(d, a, b, c, x[10], 9, 0x2441453); /* 22 */ GG(c, d, a, b, x[15], 14, 0xd8a1e681); /* 23 */ GG(b, c, d, a, x[ 4], 20, 0xe7d3fbc8); /* 24 */ GG(a, b, c, d, x[ 9], 5, 0x21e1cde6); /* 25 */ GG(d, a, b, c, x[14], 9, 0xc33707d6); /* 26 */ GG(c, d, a, b, x[ 3], 14, 0xf4d50d87); /* 27 */ GG(b, c, d, a, x[ 8], 20, 0x455a14ed); /* 28 */ GG(a, b, c, d, x[13], 5, 0xa9e3e905); /* 29 */ GG(d, a, b, c, x[ 2], 9, 0xfcefa3f8); /* 30 */ GG(c, d, a, b, x[ 7], 14, 0x676f02d9); /* 31 */ GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); /* 32 */ /* Round 3 */ HH(a, b, c, d, x[ 5], 4, 0xfffa3942); /* 33 */ HH(d, a, b, c, x[ 8], 11, 0x8771f681); /* 34 */ HH(c, d, a, b, x[11], 16, 0x6d9d6122); /* 35 */ HH(b, c, d, a, x[14], 23, 0xfde5380c); /* 36 */ HH(a, b, c, d, x[ 1], 4, 0xa4beea44); /* 37 */ HH(d, a, b, c, x[ 4], 11, 0x4bdecfa9); /* 38 */ HH(c, d, a, b, x[ 7], 16, 0xf6bb4b60); /* 39 */ HH(b, c, d, a, x[10], 23, 0xbebfbc70); /* 40 */ HH(a, b, c, d, x[13], 4, 0x289b7ec6); /* 41 */ HH(d, a, b, c, x[ 0], 11, 0xeaa127fa); /* 42 */ HH(c, d, a, b, x[ 3], 16, 0xd4ef3085); /* 43 */ HH(b, c, d, a, x[ 6], 23, 0x4881d05); /* 44 */ HH(a, b, c, d, x[ 9], 4, 0xd9d4d039); /* 45 */ HH(d, a, b, c, x[12], 11, 0xe6db99e5); /* 46 */ HH(c, d, a, b, x[15], 16, 0x1fa27cf8); /* 47 */ HH(b, c, d, a, x[ 2], 23, 0xc4ac5665); /* 48 */ /* Round 4 */ II(a, b, c, d, x[ 0], 6, 0xf4292244); /* 49 */ II(d, a, b, c, x[ 7], 10, 0x432aff97); /* 50 */ II(c, d, a, b, x[14], 15, 0xab9423a7); /* 51 */ II(b, c, d, a, x[ 5], 21, 0xfc93a039); /* 52 */ II(a, b, c, d, x[12], 6, 0x655b59c3); /* 53 */ II(d, a, b, c, x[ 3], 10, 0x8f0ccc92); /* 54 */ II(c, d, a, b, x[10], 15, 0xffeff47d); /* 55 */ II(b, c, d, a, x[ 1], 21, 0x85845dd1); /* 56 */ II(a, b, c, d, x[ 8], 6, 0x6fa87e4f); /* 57 */ II(d, a, b, c, x[15], 10, 0xfe2ce6e0); /* 58 */ II(c, d, a, b, x[ 6], 15, 0xa3014314); /* 59 */ II(b, c, d, a, x[13], 21, 0x4e0811a1); /* 60 */ II(a, b, c, d, x[ 4], 6, 0xf7537e82); /* 61 */ II(d, a, b, c, x[11], 10, 0xbd3af235); /* 62 */ II(c, d, a, b, x[ 2], 15, 0x2ad7d2bb); /* 63 */ II(b, c, d, a, x[ 9], 21, 0xeb86d391); /* 64 */ state[0] += a; state[1] += b; state[2] += c; state[3] += d; }

void MD5ToString(const unsigned char *_input, char *_output)
{
int i = 0;
for(i=0; i<16; ++i)
{
char cTemp[3] = {0};
sprintf(cTemp, "%02x", _input[i]);
strcat(_output+i, cTemp);
}
int nLen = strlen(_output);
_output[nLen] = '';
}

void MD5Encryption(const char *_input, int nLen, char *_output)
{
MD5_CTX md5;
MD5Init(&md5);
char *pBuf = (char*)malloc(nLen * sizeof(char) + 1);
memset(pBuf, 0, nLen+1);
strncpy(pBuf, _input, nLen);
pBuf[nLen] = '';

MD5Update(&md5, (unsigned char*)pBuf, strlen((char*)pBuf));

unsigned char outBuf[33] = {0};
MD5Final(&md5, outBuf);

free(pBuf);

MD5ToString(outBuf, _output);
}
//

测试代码:

// 无额外2个函数的测试方法
int i;  
unsigned char encrypt[] ="admin";//21232f297a57a5a743894a0e4a801fc3  
unsigned char decrypt[16];      
MD5_CTX md5;  
MD5Init(&md5);                
MD5Update(&md5,encrypt,strlen((char *)encrypt));  
MD5Final(&md5,decrypt);          
printf("加密前:%s
加密后:",encrypt);  
for(i=0;i<16;i++)  
{  
    printf("%02x",decrypt[i]);  
}
// 封装后的调用方法
char *pSource = "12345";
char cMD5Buf[33] = {0};
MD5Encryption(pSource, stelen(pSource), cMD5Buf); // cMD5Buf存放MD5加密码

 

 

原文地址:https://www.cnblogs.com/sylar-liang/p/4567834.html