C++ MD5的源码实例详解
C++MD5源码：
md5.h:
#ifndefMD5_H
#defineMD5_H
#include<string>
#include<fstream>
/*Typedefine*/
typedefunsignedcharbyte;
typedefunsignedintuint32;
usingstd::string;
usingstd::ifstream;
/*MD5declaration.*/
classMD5{
public:
MD5();
MD5(constvoid*input,size_tlength);
MD5(conststring&str);
MD5(ifstream&in);
voidupdate(constvoid*input,size_tlength);
voidupdate(conststring&str);
voidupdate(ifstream&in);
constbyte*digest();
stringtoString();
voidreset();
private:
voidupdate(constbyte*input,size_tlength);
voidfinal();
voidtransform(constbyteblock[64]);
voidencode(constuint32*input,byte*output,size_tlength);
voiddecode(constbyte*input,uint32*output,size_tlength);
stringbytesToHexString(constbyte*input,size_tlength);
/*classuncopyable*/
MD5(constMD5&);
MD5&operator=(constMD5&);
private:
uint32_state[4];/*state(ABCD)*/
uint32_count[2];/*numberofbits,modulo2^64(low-orderwordfirst)*/
byte_buffer[64];/*inputbuffer*/
byte_digest[16];/*messagedigest*/
bool_finished;/*calculatefinished?*/
staticconstbytePADDING[64];/*paddingforcalculate*/
staticconstcharHEX[16];
staticconstsize_tBUFFER_SIZE=1024;
};
#endif/*MD5_H*/
md5.cpp:
#include"md5.h"
usingnamespacestd;
/*ConstantsforMD5Transformroutine.*/
#defineS117
#defineS1212
#defineS1317
#defineS1422
#defineS215
#defineS229
#defineS2314
#defineS2420
#defineS314
#defineS3211
#defineS3316
#defineS3423
#defineS416
#defineS4210
#defineS4315
#defineS4421
/*F,G,HandIarebasicMD5functions.
*/
#defineF(x,y,z)(((x)&(y))|((~x)&(z)))
#defineG(x,y,z)(((x)&(z))|((y)&(~z)))
#defineH(x,y,z)((x)^(y)^(z))
#defineI(x,y,z)((y)^((x)|(~z)))
/*ROTATE_LEFTrotatesxleftnbits.
*/
#defineROTATE_LEFT(x,n)(((x)<<(n))|((x)>>(32-(n))))
/*FF,GG,HH,andIItransformationsforrounds1,2,3,and4.
Rotationisseparatefromadditiontopreventrecomputation.
*/
#defineFF(a,b,c,d,x,s,ac){\
(a)+=F((b),(c),(d))+(x)+ac;\
(a)=ROTATE_LEFT((a),(s));\
(a)+=(b);\
}
#defineGG(a,b,c,d,x,s,ac){\
(a)+=G((b),(c),(d))+(x)+ac;\
(a)=ROTATE_LEFT((a),(s));\
(a)+=(b);\
}
#defineHH(a,b,c,d,x,s,ac){\
(a)+=H((b),(c),(d))+(x)+ac;\
(a)=ROTATE_LEFT((a),(s));\
(a)+=(b);\
}
#defineII(a,b,c,d,x,s,ac){\
(a)+=I((b),(c),(d))+(x)+ac;\
(a)=ROTATE_LEFT((a),(s));\
(a)+=(b);\
}
constbyteMD5::PADDING[64]={0x80};
constcharMD5::HEX[16]={
'0','1','2','3',
'4','5','6','7',
'8','9','a','b',
'c','d','e','f'
};
/*Defaultconstruct.*/
MD5::MD5(){
reset();
}
/*ConstructaMD5objectwithainputbuffer.*/
MD5::MD5(constvoid*input,size_tlength){
reset();
update(input,length);
}
/*ConstructaMD5objectwithastring.*/
MD5::MD5(conststring&str){
reset();
update(str);
}
/*ConstructaMD5objectwithafile.*/
MD5::MD5(ifstream&in){
reset();
update(in);
}
/*Returnthemessage-digest*/
constbyte*MD5::digest(){
if(!_finished){
_finished=true;
final();
}
return_digest;
}
/*Resetthecalculatestate*/
voidMD5::reset(){
_finished=false;
/*resetnumberofbits.*/
_count[0]=_count[1]=0;
/*Loadmagicinitializationconstants.*/
_state[0]=0x67452301;
_state[1]=0xefcdab89;
_state[2]=0x98badcfe;
_state[3]=0x10325476;
}
/*Updatingthecontextwithainputbuffer.*/
voidMD5::update(constvoid*input,size_tlength){
update((constbyte*)input,length);
}
/*Updatingthecontextwithastring.*/
voidMD5::update(conststring&str){
update((constbyte*)str.c_str(),str.length());
}
/*Updatingthecontextwithafile.*/
voidMD5::update(ifstream&in){
if(!in)
return;
std::streamsizelength;
charbuffer[BUFFER_SIZE];
while(!in.eof()){
in.read(buffer,BUFFER_SIZE);
length=in.gcount();
if(length>0)
update(buffer,length);
}
in.close();
}
/*MD5blockupdateoperation.ContinuesanMD5message-digest
operation,processinganothermessageblock,andupdatingthe
context.
*/
voidMD5::update(constbyte*input,size_tlength){
uint32i,index,partLen;
_finished=false;
/*Computenumberofbytesmod64*/
index=(uint32)((_count[0]>>3)&0x3f);
/*updatenumberofbits*/
if((_count[0]+=((uint32)length<<3))<((uint32)length<<3))
_count[1]++;
_count[1]+=((uint32)length>>29);
partLen=64-index;
/*transformasmanytimesaspossible.*/
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;
}
/*Bufferremaininginput*/
memcpy(&_buffer[index],&input[i],length-i);
}
/*MD5finalization.EndsanMD5message-_digestoperation,writingthe
themessage_digestandzeroizingthecontext.
*/
voidMD5::final(){
bytebits[8];
uint32oldState[4];
uint32oldCount[2];
uint32index,padLen;
/*Savecurrentstateandcount.*/
memcpy(oldState,_state,16);
memcpy(oldCount,_count,8);
/*Savenumberofbits*/
encode(_count,bits,8);
/*Padoutto56mod64.*/
index=(uint32)((_count[0]>>3)&0x3f);
padLen=(index<56)?(56-index):(120-index);
update(PADDING,padLen);
/*Appendlength(beforepadding)*/
update(bits,8);
/*Storestateindigest*/
encode(_state,_digest,16);
/*Restorecurrentstateandcount.*/
memcpy(_state,oldState,16);
memcpy(_count,oldCount,8);
}
/*MD5basictransformation.Transforms_statebasedonblock.*/
voidMD5::transform(constbyteblock[64]){
uint32a=_state[0],b=_state[1],c=_state[2],d=_state[3],x[16];
decode(block,x,64);
/*Round1*/
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*/
/*Round2*/
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*/
/*Round3*/
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*/
/*Round4*/
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;
}
/*Encodesinput(ulong)intooutput(byte).Assumeslengthis
amultipleof4.
*/
voidMD5::encode(constuint32*input,byte*output,size_tlength){
for(size_ti=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);
}
}
/*Decodesinput(byte)intooutput(ulong).Assumeslengthis
amultipleof4.
*/
voidMD5::decode(constbyte*input,uint32*output,size_tlength){
for(size_ti=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);
}
}
/*Convertbytearraytohexstring.*/
stringMD5::bytesToHexString(constbyte*input,size_tlength){
stringstr;
str.reserve(length<<1);
for(size_ti=0;i<length;i++){
intt=input[i];
inta=t/16;
intb=t%16;
str.append(1,HEX[a]);
str.append(1,HEX[b]);
}
returnstr;
}
/*Convertdigesttostringvalue*/
stringMD5::toString(){
returnbytesToHexString(digest(),16);
}
测试文件test.cpp:
#include"md5.h"
#include<iostream>
usingnamespacestd;
voidPrintMD5(conststring&str,MD5&md5){
cout<<"MD5(\""<<str<<"\")="<<md5.toString()<<endl;
}
stringFileDigest(conststring&file){
ifstreamin(file.c_str(),ios::binary);
if(!in)
return"";
MD5md5;
std::streamsizelength;
charbuffer[1024];
while(!in.eof()){
in.read(buffer,1024);
length=in.gcount();
if(length>0)
md5.update(buffer,length);
}
in.close();
returnmd5.toString();
}
intmain(){
cout<<MD5("abc").toString()<<endl;
cout<<MD5(ifstream("D:\\test.txt")).toString()<<endl;
cout<<MD5(ifstream("D:\\test.exe",ios::binary)).toString()<<endl;
cout<<FileDigest("D:\\test.exe")<<endl;
MD5md5;
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("messagedigest");
PrintMD5("messagedigest",md5);
md5.reset();
md5.update(ifstream("D:\\test.txt"));
PrintMD5("D:\\test.txt",md5);
return0;
}
类MD5封装了与MD5相关的操作,其有
4个构造函数:
MD5();//默认构造函数 MD5(constvoid*input,size_tlength);//输入内存地址与长度信息的构造函数 MD5(conststring&str);//输入字符串的构造函数 MD5(ifstream&in);//输入流的构造函数 3个Update函数: voidupdate(constvoid*input,size_tlength);//往MD5对象内添加内存块 voidupdate(conststring&str);//添加字符串 voidupdate(ifstream&in);//添加流 constbyte*digest();//计算MD5码,并返回指向它的指针 stringtoString();//计算MD5,并返回其对应的字符串 voidreset();//重置,
test.cpp文件内的main函数描述了MD5类的用法。
相关文章：
C++MD5源码：https://www.nhooo.com/article/103113.htm
C语言MD5源码：https://www.nhooo.com/article/103108.htm
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