MD5 Encryption algorithm

MD5 Features:
1. Input any length of information, after processing, the output is 128 bits of information (digital fingerprint);
2. Different inputs to obtain different results (uniqueness);
3. It is impossible to reverse the input information (irreversible) according to the output of 128 bits;

MD5 use: Add the following header file and implementation file

string C,key;  c= "203"; MD5 iMD5;  IMD5.GENERATEMD5 (unsigned char*) c.c_str (), c.size ());  Key = Imd5.tostring ();

Header file:

#ifndef _cmd5_h #define _CMD5_H//#pragma warning (disable:4786) #include <string> using namespace std;  /*!  * Manage MD5. */class MD5 {private: #define UINT8 unsigned char #define uint32 unsigned long int struct md5_conte          XT {UInt32 total[2];          UInt32 State[4];      Uint8 buffer[64];        };      void Md5_starts (struct md5_context *ctx);      void md5_process (struct md5_context *ctx, uint8 data[64]);      void Md5_update (struct md5_context *ctx, uint8 *input, uint32 length);    void Md5_finish (struct md5_context *ctx, uint8 digest[16]); Public://!        Construct a CMD5 from any buffer void GenerateMD5 (unsigned char* buffer,int bufferlen); //!        Construct a CMD5 MD5 (); //!        Construct a md5src from char * MD5 (const char * md5src); //!        Construct a CMD5 from a bytes md5 MD5 (unsigned long* md5src); //!        Add a other MD5 MD5 operator + (MD5 adder); //!Just if equal bool operator = = (MD5 cmper); //!        Give the value from Equer//void operator = (CMD5 equer); //!        To a string string ToString ();  unsigned long m_data[4];  };   #endif/* md5.h */

Implementation file:

/* * RFC 1321 compliant MD5 implementation, * by Christophe Devine <[email protected]>; * This program is licensed under the GPL. */#include "Md5.h" #include <stdio.h> #include <stdlib.h> #include <string.h> #define GET_UINT32 (N,b,                                                                                          i) { (n) = (UInt32) ((uint8 *) b) [(i)] | (((UInt32) (((uint8 *) b) [(i) +1]) << 8) | (((UInt32) (((uint8 *) b) [(i) +2]) << 16) |               (((UInt32) (((uint8 *) b) [(i) +3]) << 24);                                                                                                  } #define PUT_UINT32 (n,b,i) {                 (((uint8 *) b) [(i)]) = (uint8) (((n)) & 0xFF);          (((uint8 *) b) [(i) +1]) = (uint8) (((n) >> 8) & 0xFF); (((uint8 *) b) [(i)+2]) = (uint8) (((n) >>) & 0xFF);     (((uint8 *) b) [(i) +3]) = (uint8) (((n) >>) & 0xFF);    }//extern pthread_mutex_t mutexmemory;void md5::md5_starts (struct md5_context *ctx) {ctx->total[0] = 0;    CTX-&GT;TOTAL[1] = 0;    Ctx->state[0] = 0x67452301;    CTX-&GT;STATE[1] = 0xefcdab89;    CTX-&GT;STATE[2] = 0x98badcfe; CTX-&GT;STATE[3] = 0x10325476;}    void md5::md5_process (struct md5_context *ctx, uint8 data[64]) {UInt32 A, B, C, D, x[16];    Get_uint32 (x[0], data, 0);    Get_uint32 (x[1], data, 4);    Get_uint32 (x[2], data, 8);    Get_uint32 (x[3], data, 12);    Get_uint32 (x[4], data, 16);    Get_uint32 (x[5], data, 20);    Get_uint32 (x[6], data, 24);    Get_uint32 (x[7], data, 28);    Get_uint32 (X[8], data, 32);    Get_uint32 (x[9], data, 36);    Get_uint32 (x[10], data, 40);    Get_uint32 (x[11], data, 44);    Get_uint32 (x[12], data, 48);    Get_uint32 (x[13], data, 52); Get_uint32 (x[14], data, 56); Get_uint32 (x[15], data, each); #define S (X,n) ((X << N) | ((x & 0xFFFFFFFF) >> (32-n)))                                                                               #define P (a,b,c,d,k,s,t) { A + = F (b,c,d) + x[k] + t;      A = S (a,s) + B;    } A = ctx->state[0];    B = ctx->state[1];    C = ctx->state[2];    D = ctx->state[3]; #define F (x, Y, z) (z ^) P (A, B, C, D, 0, 7, 0xd76aa478);    P (D, A, B, C, 1, 0xe8c7b756);    P (C, D, A, B, 2, N, 0x242070db);    P (B, C, D, A, 3, 0xc1bdceee);    P (A, B, C, D, 4, 7, 0XF57C0FAF);    P (D, A, B, C, 5, 0x4787c62a);    P (C, D, A, B, 6, N, 0xa8304613);    P (B, C, D, A, 7, 0xfd469501);    P (A, B, C, D, 8, 7, 0X698098D8);    P (D, A, B, C, 9, 0X8B44F7AF);    P (C, D, A, B, ten, N, 0XFFFF5BB1);    P (B, C, D, A, one, A, 0x895cd7be);    P (A, B, C, D, 7, 0x6b901122);   P (D, A, B, C, 0xfd987193, N); P (C, D, A, B, +, 0xa679438e); P (b, C, D, A, 1, p, 0x49b40821); #undef f#define F (z & (x ^ y)) (y ^) (A, B, C, D, 5, 0xf61e2562    );    P (D, A, B, C, 6, 9, 0xc040b340);    P (C, D, A, B, one, A, 0x265e5a51);    P (B, C, D, A, 0, 0XE9B6C7AA);    P (A, B, C, D, 5, 5, 0xd62f105d);    P (D, A, B, C, ten, 9, 0x02441453);    P (C, D, A, B, N, 0xd8a1e681);    P (B, C, D, A, 4, 0XE7D3FBC8);    P (A, B, C, D, 9, 5, 0X21E1CDE6);    P (D, A, B, C, 9, 0xc33707d6);    P (C, D, A, B, 3, 0xf4d50d87);    P (B, C, D, A, 8, 0x455a14ed);    P (A, B, C, D, 5, 0xa9e3e905);    P (D, A, B, C, 2, 9, 0XFCEFA3F8);    P (C, D, A, B, 7, 0X676F02D9);    P (b, C, D, A, A, B, 0x8d2a4c8a), #undef F #define F (x, Y, z) p (A, B., C, D, 5, 4, 0xfffa3942);    P (D, A, B, C, 8, one, 0x8771f681);    P (C, D, A, B, one, A, 0x6d9d6122);    P (B, C, D, A, +, 0xfde5380c); P (A, B, C, D, 1, 4, 0xa4beea44);    P (D, A, B, C, 4, one, 0x4bdecfa9);    P (C, D, A, B, 7, 0xf6bb4b60);    P (B, C, D, A, ten, Max, 0XBEBFBC70);    P (A, B, C, D, 4, 0X289B7EC6);    P (D, A, B, C, 0, one, 0XEAA127FA);    P (C, D, A, B, 3, 0xd4ef3085);    P (B, C, D, A, 6, 23°c, 0X04881D05);    P (A, B, C, D, 9, 4, 0xd9d4d039);    P (D, A, B, C, N, one, 0xe6db99e5);    P (C, D, A, B, 0x1fa27cf8);    P (b, C, D, A, 2, p, 0xc4ac5665); #undef f#define F (x, Y, z) (~z) (A, B, C, D, 0, 6, 0xf4292244);    P (D, A, B, C, 7, ten, 0X432AFF97);    P (C, D, A, B, +, 0XAB9423A7);    P (B, C, D, A, 5, 0xfc93a039);    P (A, B, C, D, 6, 0X655B59C3);    P (D, A, B, C, 3, ten, 0x8f0ccc92);    P (C, D, A, B, ten, 0xffeff47d);    P (B, C, D, A, 1, 0X85845DD1);    P (A, B, C, D, 8, 6, 0x6fa87e4f);    P (D, A, B, C, +, 0XFE2CE6E0);    P (C, D, A, B, 6, 0xa3014314);    P (B, C, D, A, +, 0X4E0811A1); P (A, B, C, D, 4, 6, 0xf7537e82);    P (D, A, B, C, one, ten, 0xbd3af235);    P (C, D, A, B, 2, 0X2AD7D2BB);    P (B, C, D, A, 9, 0xeb86d391); #undef F ctx->state[0] + A;    CTX-&GT;STATE[1] + = B;    CTX-&GT;STATE[2] + = C; CTX-&GT;STATE[3] + = D;}    void Md5::md5_update (struct md5_context *ctx, uint8 *input, UInt32 length) {UInt32 left, fill;    if (! length) return;    left = (Ctx->total[0] >> 3) & 0x3F;    fill = 64-left;    Ctx->total[0] + = length << 3;    CTX-&GT;TOTAL[1] + = length >> 29;    Ctx->total[0] &= 0xFFFFFFFF;    CTX-&GT;TOTAL[1] + = Ctx->total[0] < length << 3;        if (left && length >= fill) {memcpy (void *) (Ctx->buffer + left), (void *) input, fill);        Md5_process (CTX, Ctx->buffer);        Length-= fill;        Input + = fill;    left = 0;        } while (length >=) {md5_process (CTX, input);        Length-= 64;    Input + = 64;       } if (length) { memcpy (void *) (Ctx->buffer + left), (void *) input, length); }}static uint8 md5_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};void M    D5::md5_finish (struct Md5_context *ctx, uint8 digest[16]) {UInt32 last, Padn;    Uint8 Msglen[8];    Put_uint32 (Ctx->total[0], Msglen, 0);    Put_uint32 (Ctx->total[1], Msglen, 4);    Last = (Ctx->total[0] >> 3) & 0x3F; Padn = (Last < 56)?    (56-last): (120-last);    Md5_update (CTX, md5_padding, PADN);    Md5_update (CTX, Msglen, 8);    Put_uint32 (Ctx->state[0], digest, 0);    Put_uint32 (Ctx->state[1], Digest, 4);    Put_uint32 (Ctx->state[2], Digest, 8); Put_uint32 (Ctx->state[3], Digest, 12);}    void Md5::generatemd5 (unsigned char* buffer,int bufferlen) {struct Md5_context context; Md5_starts (&cOntext);    Md5_update (&context, buffer, bufferlen); Md5_finish (&context, (unsigned char*) m_data);} Md5::md5 () {for (int i=0;i<4;i++) m_data[i]=0;} MD5::MD5 (unsigned long* md5src) {memcpy (m_data,md5src,16);}    int _httoi (const char *value) {struct Chexmap {char chr;  int value;  };  const int HEXMAPL = 16;    Chexmap HEXMAP[HEXMAPL] = {{' 0 ', 0}, {' 1 ', 1}, {' 2 ', 2}, {' 3 ', 3}, {' 4 ', 4}, {' 5 ', 5}, {' 6 ', 6},  {' 8 ', 8}, {' 9 ', 9}, {' A ', ' ten} ', {' B ', ' one} ', {' C ', +}, {' d ', ', ',}, {' E ', +}, {' F ', 15}};  Pthread_mutex_lock (&mutexmemory);  Char *mstr = strdup (value);  Pthread_mutex_unlock (&mutexmemory);  char *s = MSTR;  int result = 0;  if (*s = = ' 0 ' && * (s + 1) = = ' X ') s + = 2;  BOOL Firsttime = true;    while (*s! = '/0 ') {bool found = false;        for (int i = 0; i < HEXMAPL; i++) {if (*s = = HEXMAP[I].CHR) {if (!firsttime) result <<= 4;        Result |= Hexmap[i].value; Found = true;      Break    }} if (!found) break;    s++;  Firsttime = false;  }//pthread_mutex_lock (&mutexmemory);  Free (MSTR);  Pthread_mutex_unlock (&mutexmemory); return result;}        MD5::MD5 (const char* MD5SRC) {if (strcmp (MD5SRC, "") ==0) {for (int i=0;i<4;i++) m_data[i]=0;    Return        } for (int j = 0; J <; J + +) {char buf[10];        strncpy (buf,md5src,2);        md5src+=2; ((unsigned char*) m_data)    [j] = _httoi (BUF);    }}MD5 Md5::operator + (MD5 adder) {unsigned long m_newdata[4];    for (int i=0;i<4;i++) m_newdata[i]=m_data[i]^ (Adder.m_data[i]); Return MD5 (M_newdata);} BOOL Md5::operator = = (MD5 cmper) {return (memcmp (Cmper.m_data, m_data,16) ==0);}    void Md5::operator = (MD5 equer)//{//memcpy (m_data,equer.m_data, +);//}string md5::tostring () {char output[33];    for (int j = 0; J <; J + +) {sprintf (output + J * 2, "%02x", ((unsigned char*) m_data) [j]); } return STring (output);} 

　　

MD5 Encryption algorithm