C++ md5 algorithm implementation code
- 2020-05-26 09:51:33
- OfStack
I found a copy of c++ MD5 on the Internet, and I simply saved 1:
First md5 h
#ifndef MD5_H
#define MD5_H
#include <string>
#include <fstream>
/* Type define */
typedef unsigned char byte;
typedef unsigned long ulong;
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 ulong *input, byte *output, size_t length);
void decode(const byte *input, ulong *output, size_t length);
string bytesToHexString(const byte *input, size_t length);
/* class uncopyable */
MD5(const MD5&);
MD5& operator=(const MD5&);
private:
ulong _state[4]; /* state (ABCD) */
ulong _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*/Then the implementation of the interface (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) {
ulong i, index, partLen;
_finished = false;
/* Compute number of bytes mod 64 */
index = (ulong)((_count[0] >> 3) & 0x3f);
/* update number of bits */
if((_count[0] += ((ulong)length << 3)) < ((ulong)length << 3))
_count[1]++;
_count[1] += ((ulong)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];
ulong oldState[4];
ulong oldCount[2];
ulong 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 = (ulong)((_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]) {
ulong 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 ulong *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, ulong *output, size_t length) {
for(size_t i=0, j=0; j<length; i++, j+=4) {
output[i] = ((ulong)input[j]) | (((ulong)input[j+1]) << 8) |
(((ulong)input[j+2]) << 16) | (((ulong)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);
}//test.cpp
#include "md5.h"
#include <iostream>
using namespace std;
void PrintMD5(const string &str, MD5 &md5) {
cout << "MD5(\"" << str << "\") = " << md5.toString() << endl;
}
string FileDigest(const string &file) {
ifstream in(file.c_str(), ios::binary);
if (!in)
return "";
MD5 md5;
std::streamsize length;
char buffer[1024];
while (!in.eof()) {
in.read(buffer, 1024);
length = in.gcount();
if (length > 0)
md5.update(buffer, length);
}
in.close();
return md5.toString();
}
int main() {
cout << MD5("abc").toString() << endl;
cout << FileDigest("D:\\staticDll.dll") << endl;
return 0;
}Finally, in the main function, one is the md5 code to generate the string, and the other is to read the file to generate md5 code, and then compare it with md5 code 1 generated by python to determine whether the file has been modified or not.
Since you need to validate the file, you should use the md5 algorithm. It is not easy to generate the md5 value of the file with the python script
#-*- coding:utf-8 � *-
import os,sys
from hashlib import md5
# Of the file MD5 The check code is a summary of the information generated according to the content of the file. The method is as follows:
<span style="background-color: rgb(255, 0, 0);">def md5_file(name):
m = md5()
fd = open(name, 'rb') # You need to use 2 The base format reads the contents of the file
m.update(fd.read())
fd.close()
return m.hexdigest()</span>
def usage():
print 'Usage:'
print 'timestamp.py dllFilesFullPath md5Path'
print ' Handle file dll Folder path Stored file path ( txt Format) '
if(len(sys.argv)<3): # If the parameter is wrong, give a hint
usage()
sys.exit(0)
dllFilePath = sys.argv[1]
md5File = sys.argv[2]
f = open(md5File, 'wb')
listfile=os.listdir(dllFilePath)
for name in listfile:
<span style="white-space:pre"> </span>ext_name = name[-4:]
<span style="white-space:pre"> </span>if ext_name =='.dll' or ext_name=='.exe':
<span style="white-space:pre"> </span>dllName = '%s/%s' % (dllFilePath,name)
<span style="white-space:pre"> </span>mdKey = md5_file(dllName)
<span style="white-space:pre"> </span>f.write(name)
<span style="white-space:pre"> </span>f.write('\n')
<span style="white-space:pre"> </span>f.write(mdKey)
<span style="white-space:pre"> </span>f.write('\n')
f.close()A few lines of code, plus the opening of the file. Finally, txt contains the name of the dll or exe file and md5. For simplicity, the odd line is the file name, and the even line is the md5 value
But using c++ to read the file to verify the value of md5 is a bit of a hassle