这篇文章主要介绍“C++ 递归遍历文件并计算MD5的方法”，在日常操作中，相信很多人在C++ 递归遍历文件并计算MD5的方法问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”C++ 递归遍历文件并计算MD5的方法”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
递归遍历文件夹，对比文件md5
首先，需要引用 md5 的相关代码，参考这篇文章，防止链接内容被删除，这里再记录一次：
md5.h
#ifndef MD5_H #define MD5_H #include <string> #include <fstream> typedef unsigned char byte; typedef unsigned int uint32; using std::string; using std::ifstream; 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 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); MD5(const MD5&); MD5& operator=(const MD5&); private: uint32 _state[4]; uint32 _count[2]; byte _buffer[64]; byte _digest[16]; bool _finished; static const byte PADDING[64]; static const char HEX[16]; enum { BUFFER_SIZE = 1024 }; }; #endif md5.cpp
#include "md5.h" using namespace std; #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 #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); } 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‘ }; MD5::MD5() { reset(); } MD5::MD5(const void* input, size_t length) { reset(); update(input, length); } MD5::MD5(const string& str) { reset(); update(str); } MD5::MD5(ifstream& in) { reset(); update(in); } const byte* MD5::digest() { if (!_finished) { _finished = true; final(); } return _digest; } void MD5::reset() { _finished = false; _count[0] = _count[1] = 0; _state[0] = 0x67452301; _state[1] = 0xefcdab89; _state[2] = 0x98badcfe; _state[3] = 0x10325476; } void MD5::update(const void* input, size_t length) { update((const byte*)input, length); } void MD5::update(const string& str) { update((const byte*)str.c_str(), str.length()); } 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(); } void MD5::update(const byte* input, size_t length) { uint32 i, index, partLen; _finished = false; index = (uint32)((_count[0] >> 3) & 0x3f); if ((_count[0] += ((uint32)length << 3)) < ((uint32)length << 3)) { ++_count[1]; } _count[1] += ((uint32)length >> 29); partLen = 64 - index; 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; } memcpy(&_buffer[index], &input[i], length - i); } void MD5::final() { byte bits[8]; uint32 oldState[4]; uint32 oldCount[2]; uint32 index, padLen; memcpy(oldState, _state, 16); memcpy(oldCount, _count, 8); encode(_count, bits, 8); index = (uint32)((_count[0] >> 3) & 0x3f); padLen = (index < 56) ? (56 - index) : (120 - index); update(PADDING, padLen); update(bits, 8); encode(_state, _digest, 16); memcpy(_state, oldState, 16); memcpy(_count, oldCount, 8); } void MD5::transform(const byte block[64]) { uint32 a = _state[0], b = _state[1], c = _state[2], d = _state[3], x[16]; decode(block, x, 64); FF (a, b, c, d, x[ 0], S11, 0xd76aa478); FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); FF (c, d, a, b, x[ 2], S13, 0x242070db); FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); FF (d, a, b, c, x[ 5], S12, 0x4787c62a); FF (c, d, a, b, x[ 6], S13, 0xa8304613); FF (b, c, d, a, x[ 7], S14, 0xfd469501); FF (a, b, c, d, x[ 8], S11, 0x698098d8); FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); FF (c, d, a, b, x[10], S13, 0xffff5bb1); FF (b, c, d, a, x[11], S14, 0x895cd7be); FF (a, b, c, d, x[12], S11, 0x6b901122); FF (d, a, b, c, x[13], S12, 0xfd987193); FF (c, d, a, b, x[14], S13, 0xa679438e); FF (b, c, d, a, x[15], S14, 0x49b40821); GG (a, b, c, d, x[ 1], S21, 0xf61e2562); GG (d, a, b, c, x[ 6], S22, 0xc040b340); GG (c, d, a, b, x[11], S23, 0x265e5a51); GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); GG (a, b, c, d, x[ 5], S21, 0xd62f105d); GG (d, a, b, c, x[10], S22, 0x2441453); GG (c, d, a, b, x[15], S23, 0xd8a1e681); GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); GG (d, a, b, c, x[14], S22, 0xc33707d6); GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); GG (b, c, d, a, x[ 8], S24, 0x455a14ed); GG (a, b, c, d, x[13], S21, 0xa9e3e905); GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); GG (c, d, a, b, x[ 7], S23, 0x676f02d9); GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); HH (a, b, c, d, x[ 5], S31, 0xfffa3942); HH (d, a, b, c, x[ 8], S32, 0x8771f681); HH (c, d, a, b, x[11], S33, 0x6d9d6122); HH (b, c, d, a, x[14], S34, 0xfde5380c); HH (a, b, c, d, x[ 1], S31, 0xa4beea44); HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); HH (b, c, d, a, x[10], S34, 0xbebfbc70); HH (a, b, c, d, x[13], S31, 0x289b7ec6); HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); HH (b, c, d, a, x[ 6], S34, 0x4881d05); HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); HH (d, a, b, c, x[12], S32, 0xe6db99e5); HH (c, d, a, b, x[15], S33, 0x1fa27cf8); HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); II (a, b, c, d, x[ 0], S41, 0xf4292244); II (d, a, b, c, x[ 7], S42, 0x432aff97); II (c, d, a, b, x[14], S43, 0xab9423a7); II (b, c, d, a, x[ 5], S44, 0xfc93a039); II (a, b, c, d, x[12], S41, 0x655b59c3); II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); II (c, d, a, b, x[10], S43, 0xffeff47d); II (b, c, d, a, x[ 1], S44, 0x85845dd1); II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); II (d, a, b, c, x[15], S42, 0xfe2ce6e0); II (c, d, a, b, x[ 6], S43, 0xa3014314); II (b, c, d, a, x[13], S44, 0x4e0811a1); II (a, b, c, d, x[ 4], S41, 0xf7537e82); II (d, a, b, c, x[11], S42, 0xbd3af235); II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); II (b, c, d, a, x[ 9], S44, 0xeb86d391); _state[0] += a; _state[1] += b; _state[2] += c; _state[3] += d; } void MD5::encode(const uint32* 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); } } void MD5::decode(const byte* input, uint32* output, size_t length) { for (size_t i = 0, j = 0; j < length; ++i, j += 4) { output[i] = ((uint32)input[j]) | (((uint32)input[j + 1]) << 8) | (((uint32)input[j + 2]) << 16) | (((uint32)input[j + 3]) << 24); } } 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; } string MD5::toString() { return bytesToHexString(digest(), 16); }调用例子:
#include "md5.h" #include <iostream> using namespace std; void PrintMD5(const string& str, MD5& md5) { cout << "MD5("" << str << "") = " << md5.toString() << endl; } int main() { MD5 md5; md5.update(""); PrintMD5("", md5); md5.update("a"); PrintMD5("a", md5); md5.update("bc"); PrintMD5("abc", md5); md5.update("defghijklmnopqrstuvwxyz"); PrintMD5("abcdefghijklmnopqrstuvwxyz", md5); md5.reset(); md5.update("message digest"); PrintMD5("message digest", md5); md5.reset(); md5.update(ifstream("D:\\test.txt")); PrintMD5("D:\\test.txt", md5); return 0; }配置好了以后开始写我们的递归遍历函数：
void findAllFile_MD5(const char * path,const char * format,string str_md5,BOOL &isFound){// 路径末尾追加 ‘\*.*‘ char newpath[200]; strcpy(newpath, path); strcat(newpath, "\\*.*"); // 找到目录下的第一个文件 #include <io.h>_finddata_t findData;long handle = _findfirst(newpath, &findData);if (handle == -1){return;} // 遍历文件和文件夹 while (_findnext(handle, &findData) == 0){ // 文件夹if (findData.attrib & _A_SUBDIR){// 文件夹名不能有敏感字符 ‘.‘、‘..‘if (strcmp(findData.name, ".") == 0 || strcmp(findData.name, "..") == 0){continue;} // 进入这个文件夹继续遍历 strcpy(newpath, path); strcat(newpath, "\\"); strcat(newpath, findData.name); findAllFile_MD5(newpath,format,str_md5,isFound);}// 文件 else{// 判断是不是指定后缀的文件 if(strstr( findData.name,format)){ // 输出（用来测试）//cout << "findData.size = " << findData.size << endl;//cout << "findData.name = " << findData.name << endl;//cout << "path = " << path << endl;// 取文件全路径string str_fullPath = path;str_fullPath+="\\"; str_fullPath+=findData.name;// 取文件 md5,判断是否匹配特征MD5 md5;md5.reset();md5.update(ifstream(str_fullPath));if(md5.toString() == str_md5){isFound = TRUE;} } } }// 关闭搜索句柄 _findclose(handle); }调用例子（遍历%temp% 下的文件）
// 获取 %temp% 目录TCHAR lpTempPathBuffer[MAX_PATH];GetTempPath(MAX_PATH,lpTempPathBuffer);// 删除末尾 ‘\‘string str_tempPath = lpTempPathBuffer;str_tempPath = str_tempPath.substr(0,str_tempPath.length()-1);// 遍历目录下所有 exe 文件,匹配 MD5BOOL isFound = FALSE;findAllFile_MD5(stringToCharP(str_tempPath),".exe","52f5ce92c6f72c7e193b560bf4e76330",isFound);if(isFound){cout << "找到了！" << endl;;}知识点扩展：
C++计算MD5
#include "md5.h"using namespace std;#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#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); \}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'};MD5::MD5() { reset();}MD5::MD5(const void* input, size_t length) { reset(); update(input, length);}MD5::MD5(const string& str) { reset(); update(str);}MD5::MD5(ifstream& in) { reset(); update(in);}const byte* MD5::digest() { if (!_finished) { _finished = true; final(); } return _digest;}void MD5::reset() { _finished = false; _count[0] = _count[1] = 0; _state[0] = 0x67452301; _state[1] = 0xefcdab89; _state[2] = 0x98badcfe; _state[3] = 0x10325476;}void MD5::update(const void* input, size_t length) { update((const byte*)input, length);}void MD5::update(const string& str) { update((const byte*)str.c_str(), str.length());}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();}void MD5::update(const byte* input, size_t length) { uint32 i, index, partLen; _finished = false; index = (uint32)((_count[0] >> 3) & 0x3f); if ((_count[0] += ((uint32)length << 3)) < ((uint32)length << 3)) { ++_count[1]; } _count[1] += ((uint32)length >> 29); partLen = 64 - index; 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; } memcpy(&_buffer[index], &input[i], length - i);}void MD5::final() { byte bits[8]; uint32 oldState[4]; uint32 oldCount[2]; uint32 index, padLen; memcpy(oldState, _state, 16); memcpy(oldCount, _count, 8); encode(_count, bits, 8); index = (uint32)((_count[0] >> 3) & 0x3f); padLen = (index < 56) ? (56 - index) : (120 - index); update(PADDING, padLen); update(bits, 8); encode(_state, _digest, 16); memcpy(_state, oldState, 16); memcpy(_count, oldCount, 8);}void MD5::transform(const byte block[64]) { uint32 a = _state[0], b = _state[1], c = _state[2], d = _state[3], x[16]; decode(block, x, 64); FF(a, b, c, d, x[0], S11, 0xd76aa478); FF(d, a, b, c, x[1], S12, 0xe8c7b756); FF(c, d, a, b, x[2], S13, 0x242070db); FF(b, c, d, a, x[3], S14, 0xc1bdceee); FF(a, b, c, d, x[4], S11, 0xf57c0faf); FF(d, a, b, c, x[5], S12, 0x4787c62a); FF(c, d, a, b, x[6], S13, 0xa8304613); FF(b, c, d, a, x[7], S14, 0xfd469501); FF(a, b, c, d, x[8], S11, 0x698098d8); FF(d, a, b, c, x[9], S12, 0x8b44f7af); FF(c, d, a, b, x[10], S13, 0xffff5bb1); FF(b, c, d, a, x[11], S14, 0x895cd7be); FF(a, b, c, d, x[12], S11, 0x6b901122); FF(d, a, b, c, x[13], S12, 0xfd987193); FF(c, d, a, b, x[14], S13, 0xa679438e); FF(b, c, d, a, x[15], S14, 0x49b40821); GG(a, b, c, d, x[1], S21, 0xf61e2562); GG(d, a, b, c, x[6], S22, 0xc040b340); GG(c, d, a, b, x[11], S23, 0x265e5a51); GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); GG(a, b, c, d, x[5], S21, 0xd62f105d); GG(d, a, b, c, x[10], S22, 0x2441453); GG(c, d, a, b, x[15], S23, 0xd8a1e681); GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); GG(a, b, c, d, x[9], S21, 0x21e1cde6); GG(d, a, b, c, x[14], S22, 0xc33707d6); GG(c, d, a, b, x[3], S23, 0xf4d50d87); GG(b, c, d, a, x[8], S24, 0x455a14ed); GG(a, b, c, d, x[13], S21, 0xa9e3e905); GG(d, a, b, c, x[2], S22, 0xfcefa3f8); GG(c, d, a, b, x[7], S23, 0x676f02d9); GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); HH(a, b, c, d, x[5], S31, 0xfffa3942); HH(d, a, b, c, x[8], S32, 0x8771f681); HH(c, d, a, b, x[11], S33, 0x6d9d6122); HH(b, c, d, a, x[14], S34, 0xfde5380c); HH(a, b, c, d, x[1], S31, 0xa4beea44); HH(d, a, b, c, x[4], S32, 0x4bdecfa9); HH(c, d, a, b, x[7], S33, 0xf6bb4b60); HH(b, c, d, a, x[10], S34, 0xbebfbc70); HH(a, b, c, d, x[13], S31, 0x289b7ec6); HH(d, a, b, c, x[0], S32, 0xeaa127fa); HH(c, d, a, b, x[3], S33, 0xd4ef3085); HH(b, c, d, a, x[6], S34, 0x4881d05); HH(a, b, c, d, x[9], S31, 0xd9d4d039); HH(d, a, b, c, x[12], S32, 0xe6db99e5); HH(c, d, a, b, x[15], S33, 0x1fa27cf8); HH(b, c, d, a, x[2], S34, 0xc4ac5665); II(a, b, c, d, x[0], S41, 0xf4292244); II(d, a, b, c, x[7], S42, 0x432aff97); II(c, d, a, b, x[14], S43, 0xab9423a7); II(b, c, d, a, x[5], S44, 0xfc93a039); II(a, b, c, d, x[12], S41, 0x655b59c3); II(d, a, b, c, x[3], S42, 0x8f0ccc92); II(c, d, a, b, x[10], S43, 0xffeff47d); II(b, c, d, a, x[1], S44, 0x85845dd1); II(a, b, c, d, x[8], S41, 0x6fa87e4f); II(d, a, b, c, x[15], S42, 0xfe2ce6e0); II(c, d, a, b, x[6], S43, 0xa3014314); II(b, c, d, a, x[13], S44, 0x4e0811a1); II(a, b, c, d, x[4], S41, 0xf7537e82); II(d, a, b, c, x[11], S42, 0xbd3af235); II(c, d, a, b, x[2], S43, 0x2ad7d2bb); II(b, c, d, a, x[9], S44, 0xeb86d391); _state[0] += a; _state[1] += b; _state[2] += c; _state[3] += d;}void MD5::encode(const uint32* 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); }}void MD5::decode(const byte* input, uint32* output, size_t length) { for (size_t i = 0, j = 0; j < length; ++i, j += 4) { output[i] = ((uint32)input[j]) | (((uint32)input[j + 1]) << 8) | (((uint32)input[j + 2]) << 16) | (((uint32)input[j + 3]) << 24); }}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;}string MD5::toString() { return bytesToHexString(digest(), 16);}到此，关于“C++ 递归遍历文件并计算MD5的方法”的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注编程网网站，小编会继续努力为大家带来更多实用的文章！
