c++ md5 算法封装
md5.h
#ifndef MD5_H
#define MD5_H #include <string>
#include <fstream> /* Type define */
typedef unsigned char byte;
typedef unsigned int uint32; 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[]);
void encode(const uint32* input, byte* output, size_t length);
void decode(const byte* input, uint32* output, size_t length);
string bytesToHexString(const byte* input, size_t length); /* class uncopyable */
MD5(const MD5&);
MD5& operator=(const MD5&); private:
uint32 _state[]; /* state (ABCD) */
uint32 _count[]; /* number of bits, modulo 2^64 (low-order word first) */
byte _buffer[]; /* input buffer */
byte _digest[]; /* message digest */
bool _finished; /* calculate finished ? */ static const byte PADDING[]; /* padding for calculate */
static const char HEX[];
enum { BUFFER_SIZE = };
}; #endif /*MD5_H*/
md5.cpp
#include "md5.h"
#include <string.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[] = { 0x80 };
const char MD5::HEX[] = {
'', '', '', '',
'', '', '', '',
'', '', '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[] = _count[] = ;
/* Load magic initialization constants. */
_state[] = 0x67452301;
_state[] = 0xefcdab89;
_state[] = 0x98badcfe;
_state[] = 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 > ) {
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) { uint32 i, index, partLen; _finished = false; /* Compute number of bytes mod 64 */
index = (uint32)((_count[] >> ) & 0x3f); /* update number of bits */
if ((_count[] += ((uint32)length << )) < ((uint32)length << )) {
++_count[];
}
_count[] += ((uint32)length >> ); partLen = - index; /* transform as many times as possible. */
if (length >= partLen) { memcpy(&_buffer[index], input, partLen);
transform(_buffer); for (i = partLen; i + < length; i += ) {
transform(&input[i]);
}
index = ; } else {
i = ;
} /* 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[];
uint32 oldState[];
uint32 oldCount[];
uint32 index, padLen; /* Save current state and count. */
memcpy(oldState, _state, );
memcpy(oldCount, _count, ); /* Save number of bits */
encode(_count, bits, ); /* Pad out to 56 mod 64. */
index = (uint32)((_count[] >> ) & 0x3f);
padLen = (index < ) ? ( - index) : ( - index);
update(PADDING, padLen); /* Append length (before padding) */
update(bits, ); /* Store state in digest */
encode(_state, _digest, ); /* Restore current state and count. */
memcpy(_state, oldState, );
memcpy(_count, oldCount, );
} /* MD5 basic transformation. Transforms _state based on block. */
void MD5::transform(const byte block[]) { uint32 a = _state[], b = _state[], c = _state[], d = _state[], x[]; decode(block, x, ); /* Round 1 */
FF (a, b, c, d, x[ ], S11, 0xd76aa478); /* 1 */
FF (d, a, b, c, x[ ], S12, 0xe8c7b756); /* 2 */
FF (c, d, a, b, x[ ], S13, 0x242070db); /* 3 */
FF (b, c, d, a, x[ ], S14, 0xc1bdceee); /* 4 */
FF (a, b, c, d, x[ ], S11, 0xf57c0faf); /* 5 */
FF (d, a, b, c, x[ ], S12, 0x4787c62a); /* 6 */
FF (c, d, a, b, x[ ], S13, 0xa8304613); /* 7 */
FF (b, c, d, a, x[ ], S14, 0xfd469501); /* 8 */
FF (a, b, c, d, x[ ], S11, 0x698098d8); /* 9 */
FF (d, a, b, c, x[ ], S12, 0x8b44f7af); /* 10 */
FF (c, d, a, b, x[], S13, 0xffff5bb1); /* 11 */
FF (b, c, d, a, x[], S14, 0x895cd7be); /* 12 */
FF (a, b, c, d, x[], S11, 0x6b901122); /* 13 */
FF (d, a, b, c, x[], S12, 0xfd987193); /* 14 */
FF (c, d, a, b, x[], S13, 0xa679438e); /* 15 */
FF (b, c, d, a, x[], S14, 0x49b40821); /* 16 */ /* Round 2 */
GG (a, b, c, d, x[ ], S21, 0xf61e2562); /* 17 */
GG (d, a, b, c, x[ ], S22, 0xc040b340); /* 18 */
GG (c, d, a, b, x[], S23, 0x265e5a51); /* 19 */
GG (b, c, d, a, x[ ], S24, 0xe9b6c7aa); /* 20 */
GG (a, b, c, d, x[ ], S21, 0xd62f105d); /* 21 */
GG (d, a, b, c, x[], S22, 0x2441453); /* 22 */
GG (c, d, a, b, x[], S23, 0xd8a1e681); /* 23 */
GG (b, c, d, a, x[ ], S24, 0xe7d3fbc8); /* 24 */
GG (a, b, c, d, x[ ], S21, 0x21e1cde6); /* 25 */
GG (d, a, b, c, x[], S22, 0xc33707d6); /* 26 */
GG (c, d, a, b, x[ ], S23, 0xf4d50d87); /* 27 */
GG (b, c, d, a, x[ ], S24, 0x455a14ed); /* 28 */
GG (a, b, c, d, x[], S21, 0xa9e3e905); /* 29 */
GG (d, a, b, c, x[ ], S22, 0xfcefa3f8); /* 30 */
GG (c, d, a, b, x[ ], S23, 0x676f02d9); /* 31 */
GG (b, c, d, a, x[], S24, 0x8d2a4c8a); /* 32 */ /* Round 3 */
HH (a, b, c, d, x[ ], S31, 0xfffa3942); /* 33 */
HH (d, a, b, c, x[ ], S32, 0x8771f681); /* 34 */
HH (c, d, a, b, x[], S33, 0x6d9d6122); /* 35 */
HH (b, c, d, a, x[], S34, 0xfde5380c); /* 36 */
HH (a, b, c, d, x[ ], S31, 0xa4beea44); /* 37 */
HH (d, a, b, c, x[ ], S32, 0x4bdecfa9); /* 38 */
HH (c, d, a, b, x[ ], S33, 0xf6bb4b60); /* 39 */
HH (b, c, d, a, x[], S34, 0xbebfbc70); /* 40 */
HH (a, b, c, d, x[], S31, 0x289b7ec6); /* 41 */
HH (d, a, b, c, x[ ], S32, 0xeaa127fa); /* 42 */
HH (c, d, a, b, x[ ], S33, 0xd4ef3085); /* 43 */
HH (b, c, d, a, x[ ], S34, 0x4881d05); /* 44 */
HH (a, b, c, d, x[ ], S31, 0xd9d4d039); /* 45 */
HH (d, a, b, c, x[], S32, 0xe6db99e5); /* 46 */
HH (c, d, a, b, x[], S33, 0x1fa27cf8); /* 47 */
HH (b, c, d, a, x[ ], S34, 0xc4ac5665); /* 48 */ /* Round 4 */
II (a, b, c, d, x[ ], S41, 0xf4292244); /* 49 */
II (d, a, b, c, x[ ], S42, 0x432aff97); /* 50 */
II (c, d, a, b, x[], S43, 0xab9423a7); /* 51 */
II (b, c, d, a, x[ ], S44, 0xfc93a039); /* 52 */
II (a, b, c, d, x[], S41, 0x655b59c3); /* 53 */
II (d, a, b, c, x[ ], S42, 0x8f0ccc92); /* 54 */
II (c, d, a, b, x[], S43, 0xffeff47d); /* 55 */
II (b, c, d, a, x[ ], S44, 0x85845dd1); /* 56 */
II (a, b, c, d, x[ ], S41, 0x6fa87e4f); /* 57 */
II (d, a, b, c, x[], S42, 0xfe2ce6e0); /* 58 */
II (c, d, a, b, x[ ], S43, 0xa3014314); /* 59 */
II (b, c, d, a, x[], S44, 0x4e0811a1); /* 60 */
II (a, b, c, d, x[ ], S41, 0xf7537e82); /* 61 */
II (d, a, b, c, x[], S42, 0xbd3af235); /* 62 */
II (c, d, a, b, x[ ], S43, 0x2ad7d2bb); /* 63 */
II (b, c, d, a, x[ ], S44, 0xeb86d391); /* 64 */ _state[] += a;
_state[] += b;
_state[] += c;
_state[] += d;
} /* Encodes input (ulong) into output (byte). Assumes length is
a multiple of 4.
*/
void MD5::encode(const uint32* input, byte* output, size_t length) { for (size_t i = , j = ; j < length; ++i, j += ) {
output[j]= (byte)(input[i] & 0xff);
output[j + ] = (byte)((input[i] >> ) & 0xff);
output[j + ] = (byte)((input[i] >> ) & 0xff);
output[j + ] = (byte)((input[i] >> ) & 0xff);
}
} /* Decodes input (byte) into output (ulong). Assumes length is
a multiple of 4.
*/
void MD5::decode(const byte* input, uint32* output, size_t length) { for (size_t i = , j = ; j < length; ++i, j += ) {
output[i] = ((uint32)input[j]) | (((uint32)input[j + ]) << ) |
(((uint32)input[j + ]) << ) | (((uint32)input[j + ]) << );
}
} /* Convert byte array to hex string. */
string MD5::bytesToHexString(const byte* input, size_t length) { string str;
str.reserve(length << );
for (size_t i = ; i < length; ++i) {
int t = input[i];
int a = t / ;
int b = t % ;
str.append(, HEX[a]);
str.append(, HEX[b]);
}
return str;
} /* Convert digest to string value */
string MD5::toString() {
return bytesToHexString(digest(), );
}