MD5源代码分析、供大家学习

最新推荐文章于 2025-06-13 09:26:38 发布

iteye_6233

最新推荐文章于 2025-06-13 09:26:38 发布

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本文提供了一个详细的MD5算法实现过程，包括初始化、消息更新、最终处理等步骤，并通过实例演示了如何使用该算法进行字符串、文件等内容的摘要生成。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

无聊之际，把加密的算法给大家。

//shiyan.cpp:定义控制台应用程序的入口点。

//#include"stdafx.h"

#include<stdio.h>

#include<time.h>

#include<string.h>

/*ConstantsforMD5Transformroutine.*/

#defineS117

#defineS1212

#defineS1317

#defineS1422

#defineS215

#defineS229

#defineS2314

#defineS2420

#defineS314

#defineS3211

#defineS3316

#defineS3423

#defineS416

#defineS4210

#defineS4315

#defineS4421

#ifndefPROTOTYPES

#definePROTOTYPES0

#endif

/*PROTO_LISTisdefineddependingonhowPROTOTYPESisdefinedabove.

IfusingPROTOTYPES,thenPROTO_LISTreturnsthelist,otherwiseit

returnsanemptylist.*/

#ifPROTOTYPES

#definePROTO_LIST(list)list

#else

#definePROTO_LIST(list)()

#endif

/*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)+(UINT4)(ac);\

(a)=ROTATE_LEFT((a),(s));\

(a)+=(b);\

}

#defineGG(a,b,c,d,x,s,ac){\

(a)+=G((b),(c),(d))+(x)+(UINT4)(ac);\

(a)=ROTATE_LEFT((a),(s));\

(a)+=(b);\

}

#defineHH(a,b,c,d,x,s,ac){\

(a)+=H((b),(c),(d))+(x)+(UINT4)(ac);\

(a)=ROTATE_LEFT((a),(s));\

(a)+=(b);\

}

#defineII(a,b,c,d,x,s,ac){\

(a)+=I((b),(c),(d))+(x)+(UINT4)(ac);\

(a)=ROTATE_LEFT((a),(s));\

(a)+=(b);\

}

#defineMD_CTXMD5_CTX

#defineMDInitMD5Init

#defineMD5UpdateMD5Update

#defineMDFinalMD5Final

/*Lengthoftestblock,numberoftestblocks.*/

#defineTEST_BLOCK_LEN10000

#defineTEST_BLOCK_COUNT10000

/*POINTERdefinesagenericpointertype*/

typedefunsignedchar*POINTER;

/*UINT2definesatwobyteword*/

typedefunsignedshortintUINT2;

/*UINT4definesafourbyteword*/

typedefunsignedlongintUINT4;

/*MD5context.*/

typedefstruct{

UINT4state[4];/*state(ABCD)*/

UINT4count[2];/*numberofbits,modulo2^64(lsbfirst)*/

unsignedcharbuffer[64];/*inputbuffer*/

}MD5_CTX;

voidMD5InitPROTO_LIST((MD5_CTX*));

voidMD5UpdatePROTO_LIST((MD5_CTX*,unsignedchar*,unsignedint));

voidMD5FinalPROTO_LIST((unsignedchar[16],MD5_CTX*));

staticvoidMD5TransformPROTO_LIST((UINT4[4],unsignedchar[64]));

staticvoidEncodePROTO_LIST((unsignedchar*,UINT4*,unsignedint));

staticvoidDecodePROTO_LIST((UINT4*,unsignedchar*,unsignedint));

staticvoidMD5_memcpyPROTO_LIST((POINTER,POINTER,unsignedint));

staticvoidMD5_memsetPROTO_LIST((POINTER,int,unsignedint));

staticunsignedcharPADDING[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

};

/*MD5initialization.BeginsanMD5operation,writinganewcontext.*/

voidMD5Init(MD5_CTX*context)

{/*context*/

context->count[0]=context->count[1]=0;

/*Loadmagicinitializationconstants.*/

context->state[0]=0x67452301;

context->state[1]=0xefcdab89;

context->state[2]=0x98badcfe;

context->state[3]=0x10325476;

}

/*Note:Replace"forloop"withstandardmemcpyifpossible.*/

staticvoidMD5_memcpy(POINTERoutput,POINTERinput,unsignedintlen)

{

unsignedinti;

for(i=0;i<len;i++)

output[i]=input[i];

}

/*Note:Replace"forloop"withstandardmemsetifpossible.*/

staticvoidMD5_memset(POINTERoutput,intvalue,unsignedintlen)

{

unsignedinti;

for(i=0;i<len;i++)

((char*)output)[i]=(char)value;

}

/*Decodesinput(unsignedchar)intooutput(UINT4).Assumeslenisamultipleof4.*/

staticvoidDecode(UINT4*output,unsignedchar*input,unsignedintlen)

{

unsignedinti,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);

}

/*MD5basictransformation.Transformsstatebasedonblock.*/

staticvoidMD5Transform(UINT4state[4],unsignedcharblock[64])

{

UINT4a=state[0],b=state[1],c=state[2],d=state[3],x[16];

Decode(x,block,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;

/*Zeroizesensitiveinformation.*/

MD5_memset((POINTER)x,0,sizeof(x));

}

/*MD5blockupdateoperation.ContinuesanMD5message-digest

operation,processinganothermessageblock,andupdatingthe

context.*/

voidMD5Update(MD5_CTX*context,unsignedchar*input,unsignedintinputLen)

{

unsignedinti,index,partLen;

/*Computenumberofbytesmod64*/

index=(unsignedint)((context->count[0]>>3)&0x3F);

/*Updatenumberofbits*/

if((context->count[0]+=((UINT4)inputLen<<3))<((UINT4)inputLen<<3))

context->count[1]++;

context->count[1]+=((UINT4)inputLen>>29);

partLen=64-index;

/*Transformasmanytimesaspossible.*/

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;

/*Bufferremaininginput*/

MD5_memcpy((POINTER)&context->buffer[index],(POINTER)&input[i],inputLen-i);

}

/*Encodesinput(UINT4)intooutput(unsignedchar).Assumeslenisamultipleof4.*/

staticvoidEncode(unsignedchar*output,UINT4*input,unsignedintlen)

{

unsignedinti,j;

for(i=0,j=0;j<len;i++,j+=4)

{

output[j]=(unsignedchar)(input[i]&0xff);

output[j+1]=(unsignedchar)((input[i]>>8)&0xff);

output[j+2]=(unsignedchar)((input[i]>>16)&0xff);

output[j+3]=(unsignedchar)((input[i]>>24)&0xff);

}

/*MD5finalization.EndsanMD5message-digestoperation,writingthe

themessagedigestandzeroizingthecontext.*/

voidMD5Final(unsignedchardigest[16],MD5_CTX*context)

{

unsignedcharbits[8];

unsignedintindex,padLen;

/*Savenumberofbits*/

Encode(bits,context->count,8);

/*Padoutto56mod64.*/

index=(unsignedint)((context->count[0]>>3)&0x3f);

padLen=(index<56)?(56-index):(120-index);

MD5Update(context,PADDING,padLen);

/*Appendlength(beforepadding)*/

MD5Update(context,bits,8);

/*Storestateindigest*/

Encode(digest,context->state,16);

/*Zeroizesensitiveinformation.*/

MD5_memset((POINTER)context,0,sizeof(*context));

}

staticvoidMDStringPROTO_LIST((char*));

staticvoidMDTimeTrialPROTO_LIST((void));

staticvoidMDTestSuitePROTO_LIST((void));

staticvoidMDFilePROTO_LIST((char*));

staticvoidMDFilterPROTO_LIST((void));

staticvoidMDPrintPROTO_LIST((unsignedchar[16]));

/*Maindriver.*/

/*Printsamessagedigestinhexadecimal.*/

staticvoidMDPrint(unsignedchardigest[16])

{

unsignedinti;

for(i=0;i<16;i++)

printf("%02x",digest[i]);

}

/*Digestsastringandprintstheresult.*/

staticvoidMDString(char*string)

{

MD5_CTXcontext;

unsignedchardigest[16];

unsignedintlen=strlen(string);

MD5Init(&context);

MD5Update(&context,(unsignedchar*)string,len);

MD5Final(digest,&context);

printf("MD5(\"%s\")=",string);

MDPrint(digest);

printf("\n");

}

/*MeasuresthetimetodigestTEST_BLOCK_COUNTTEST_BLOCK_LEN-byteblocks.*/

staticvoidMDTimeTrial()

{

MD5_CTXcontext;

time_tendTime,startTime;

unsignedcharblock[TEST_BLOCK_LEN],digest[16];

unsignedinti;

printf("MD5timetrial.Digesting%d%d-byteblocks...",TEST_BLOCK_LEN,TEST_BLOCK_COUNT);

/*Initializeblock*/

for(i=0;i<TEST_BLOCK_LEN;i++)

block[i]=(unsignedchar)(i&0xff);

/*Starttimer*/

time(&startTime);

/*Digestblocks*/

MD5Init(&context);

for(i=0;i<TEST_BLOCK_COUNT;i++)

MD5Update(&context,block,TEST_BLOCK_LEN);

MD5Final(digest,&context);

/*Stoptimer*/

time(&endTime);

printf("done\n");

printf("Digest=");

MDPrint(digest);

printf("\nTime=%ldseconds\n",(long)(endTime-startTime));

printf("Speed=%ldbytes/second\n",(long)TEST_BLOCK_LEN*(long)TEST_BLOCK_COUNT/(endTime-startTime));

}

/*Digestsareferencesuiteofstringsandprintstheresults.*/

staticvoidMDTestSuite()

{

printf("MD5testsuite:\n");

MDString("");

MDString("a");

MDString("abc");

MDString("messagedigest");

MDString("abcdefghijklmnopqrstuvwxyz");

MDString("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");

MDString("1234567890123456789012345678901234567890\1234567890123456789012345678901234567890");

}

/*Digestsafileandprintstheresult.*/

staticvoidMDFile(char*filename)

{

FILE*file;

MD5_CTXcontext;

intlen;

unsignedcharbuffer[1024],digest[16];

if((file=fopen(filename,"rb"))==NULL)

printf("%scan'tbeopened\n",filename);

else{

MD5Init(&context);

while(len=fread(buffer,1,1024,file))

MD5Update(&context,buffer,len);

MD5Final(digest,&context);

fclose(file);

printf("MD5(%s)=",filename);

MDPrint(digest);

printf("\n");

}

/*Digeststhestandardinputandprintstheresult.*/

staticvoidMDFilter()

{

MD5_CTXcontext;

intlen;

unsignedcharbuffer[16],digest[16];

MD5Init(&context);

while(len=fread(buffer,1,16,stdin)<16)

MD5Update(&context,buffer,len);

MD5Final(digest,&context);

MDPrint(digest);

printf("\n");

}

intmenu(){//菜单选择

inti;

printf("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\n");

printf("@@【1】digestsstring@@\n");

printf("@@【2】runstimetrial@@\n");

printf("@@【3】runstestscript@@\n");

printf("@@【4】digestsfile@@\n");

printf("@@【5】digestsstandardinput@@\n");

printf("@@【0】退出@@\n");

printf("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\n");

printf("请选择0~6操作:\n");

for(;;){

scanf("%d",&i);

if(i<0||i>5)

printf("选择错误，请重新选择操作，O(∩_∩)O~：\n");

else

break;

}

returni;

}

voidmain(){

while(1){

switch(menu()){

case1:

charstr[1024];

printf("请输入字符串：");

scanf("%s",str);

MDString(str);

break;

case2:

MDTimeTrial();

break;

case3:

MDTestSuite();

break;

case4:

charstr1[128];

printf("请输入文件路径及文件名：");

scanf("%s",str1);

MDFile(str1);

break;

case5:

MDFilter();

break;

case0:

return;

}

（龙铭洪）

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