计算文件MD5 (C++)

3/8/2017来源:ASP.NET技巧人气:3156

说明

md5算法详见 rfc1321,其中包含了一个c的算法,这里略作整理,并加入了计算文件MD5的代码。

实现

md5global.h, md5.h, md5.cpp 为rfc1321中提供的代码

md5global.h:

/* GLOBAL.H - RSAREF types and constants */ /* PROTOTYPES should be set to one if and only if the compiler supports function argument prototyping. The following makes PROTOTYPES default to 0 if it has not already been defined with C compiler flags. */ #ifndef MD5_GLOBAL_H #define MD5_GLOBAL_H /* 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; #endif

md5.h:

/* MD5.H - header file for MD5C.C */ /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All rights reserved. License to copy and use this software is granted provided that it is identified as the "RSA Data Security, Inc. MD5 Message-Digest Algorithm" in all material mentioning or referencing this software or this function. License is also granted to make and use derivative works provided that such works are identified as "derived from the RSA Data Security, Inc. MD5 Message-Digest Algorithm" in all material mentioning or referencing the derived work. RSA Data Security, Inc. makes no representations concerning either the merchantability of this software or the suitability of this software for any particular purpose. It is provided "as is" without express or implied warranty of any kind. These notices must be retained in any copies of any part of this documentation and/or software. */ #ifndef MD5_H #define MD5_H /* MD5 context. */ typedef struct { UINT4 state[4]; /* state (ABCD) */ UINT4 count[2]; /* number of bits, modulo 2^64 (lsb first) */ unsigned char buffer[64]; /* input buffer */ } MD5_CTX; void MD5Init(MD5_CTX *); void MD5Update(MD5_CTX *, unsigned char *, unsigned int); void MD5Final(unsigned char[16], MD5_CTX *); #endif

md5.cpp:

/* MD5.C - RSA Data Security, Inc., MD5 message-digest algorithm */ /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All rights reserved. License to copy and use this software is granted provided that it is identified as the "RSA Data Security, Inc. MD5 Message-Digest Algorithm" in all material mentioning or referencing this software or this function. License is also granted to make and use derivative works provided that such works are identified as "derived from the RSA Data Security, Inc. MD5 Message-Digest Algorithm" in all material mentioning or referencing the derived work. RSA Data Security, Inc. makes no representations concerning either the merchantability of this software or the suitability of this software for any particular purpose. It is provided "as is" without express or implied warranty of any kind. These notices must be retained in any copies of any part of this documentation and/or software. */ #include "md5global.h" #include "md5.h" /* 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 void MD5Transform(UINT4[4], unsigned char[64]); static void Encode(unsigned char *, UINT4 *, unsigned int); static void Decode(UINT4 *, unsigned char *, unsigned int); static void MD5_memcpy(POINTER, POINTER, unsigned int); static void MD5_memset(POINTER, int, unsigned int); 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); \ } /* MD5 initialization. Begins an MD5 Operation, writing a new context. */ void MD5Init(MD5_CTX *context) /* context */ { 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 MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputLen) { 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) { MD5_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 */ MD5_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. */ void MD5Final(unsigned char digest[16], MD5_CTX *context) { 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); MD5Update(context, PADDING, padLen); /* Append length (before padding) */ MD5Update(context, bits, 8); /* Store state in digest */ Encode(digest, context->state, 16); /* Zeroize sensitive information. */ MD5_memset((POINTER)context, 0, sizeof(*context)); } /* 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. */ MD5_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); } /* Note: Replace "for loop" with standard memcpy if possible. */ static void MD5_memcpy(POINTER output, POINTER input, unsigned int len) { unsigned int i; for (i = 0; i < len; i++) output[i] = input[i]; } /* Note: Replace "for loop" with standard memset if possible. */ static void MD5_memset(POINTER output, int value, unsigned int len) { unsigned int i; for (i = 0; i < len; i++) ((char *)output)[i] = (char)value; }

log.h 是用来简单记录日志的

// log.h #ifndef LOG_H #define LOG_H #include <fstream> #include <iostream> #include <atltime.h> #include <atlstr.h> #include <ShlObj.h> extern std::string logFile; #define __FILENAME__ (strrchr(__FILE__, '\\') ? (strrchr(__FILE__, '\\') + 1) : __FILE__) #define LOG(msg) \ do \ {\ std::ofstream fout(logFile.c_str(), std::ios::out | std::ios::app);\ if (fout)\ {\ CTime curTime = CTime::GetCurrentTime();\ CStringA str = curTime.Format(TEXT("[%Y-%m-%d %H:%M:%S] "));\ DWORD dwThreadId = GetCurrentThreadId();\ fout << str.GetBuffer() << dwThreadId << " " << __FILENAME__ << "(" << __LINE__ << ") " << msg << std::endl;\ std::cout << str.GetBuffer() << dwThreadId << " " << __FILENAME__ << "(" << __LINE__ << ") " << msg << std::endl;\ fout.close();\ }\ } while (false) #endif

md5file.h 计算文件md5头文件

#ifndef MD5FILE_H #define MD5FILE_H #include <string> std::string getFileMD5(const std::string& filename); #endif

md5file.cpp 计算文件md5实现

#include "md5file.h" #include "md5global.h" #include "md5.h" #include "log.h" #include <fstream> #include <iostream> #include <sstream> #include <memory> #include <iomanip> #include <exception> std::string getFileMD5(const std::string& filename) { std::ifstream fin(filename.c_str(), std::ifstream::in | std::ifstream::binary); if (fin) { // get length of file: fin.seekg(0, fin.end); unsigned int length = static_cast<int>(fin.tellg()); fin.seekg(0, fin.beg); std::unique_ptr<unsigned char[]> buffer{ new unsigned char[length] {} }; fin.read(reinterpret_cast<char*>(buffer.get()), length); if (!fin) { LOG(filename << " can't be read"); fin.close(); std::ostringstream oss; oss << "FATAL ERROR: " << filename << " can't be read" << std::ends; throw std::runtime_error(oss.str()); } fin.close(); MD5_CTX context; MD5Init(&context); MD5Update(&context, buffer.get(), length); unsigned char digest[16]; MD5Final(digest, &context); std::ostringstream oss; for (int i = 0; i < 16; ++i) { oss << std::hex << std::setw(2) << std::setfill('0') << static_cast<unsigned int>(digest[i]); } oss << std::endl; return std::move(oss.str()); } else { LOG(filename << " can't be opened"); std::ostringstream oss; oss << "FATAL ERROR: " << filename << " can't be opened" << std::ends; throw std::runtime_error(oss.str()); } }