md5函数C语言实现

头文件md5.h

#ifndefMD5_H
#defineMD5_H

typedefstruct
{
unsignedintcount[2];
unsignedintstate[4];
unsignedcharbuffer[64];
}MD5_CTX;


#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))
#defineROTATE_LEFT(x,n)((x<<n)|(x>>(32-n)))
#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;\
}
voidMD5Init(MD5_CTX*context);
voidMD5Update(MD5_CTX*context,unsignedchar*input,unsignedintinputlen);
voidMD5Final(MD5_CTX*context,unsignedchardigest[16]);
voidMD5Transform(unsignedintstate[4],unsignedcharblock[64]);
voidMD5Encode(unsignedchar*output,unsignedint*input,unsignedintlen);
voidMD5Decode(unsignedint*output,unsignedchar*input,unsignedintlen);

#endif

C语言文件md5.c

#include<memory.h>
#include"md5.h"

unsignedcharPADDING[]={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};

voidMD5Init(MD5_CTX*context)
{
context->count[0]=0;
context->count[1]=0;
context->state[0]=0x67452301;
context->state[1]=0xEFCDAB89;
context->state[2]=0x98BADCFE;
context->state[3]=0x10325476;
}
voidMD5Update(MD5_CTX*context,unsignedchar*input,unsignedintinputlen)
{
unsignedinti=0,index=0,partlen=0;
index=(context->count[0]>>3)&0x3F;
partlen=64-index;
context->count[0]+=inputlen<<3;
if(context->count[0]<(inputlen<<3))
context->count[1]++;
context->count[1]+=inputlen>>29;

if(inputlen>=partlen)
{
memcpy(&context->buffer[index],input,partlen);
MD5Transform(context->state,context->buffer);
for(i=partlen;i+64<=inputlen;i+=64)
MD5Transform(context->state,&input[i]);
index=0;
}
else
{
i=0;
}
memcpy(&context->buffer[index],&input[i],inputlen-i);
}
voidMD5Final(MD5_CTX*context,unsignedchardigest[16])
{
unsignedintindex=0,padlen=0;
unsignedcharbits[8];
index=(context->count[0]>>3)&0x3F;
padlen=(index<56)?(56-index):(120-index);
MD5Encode(bits,context->count,8);
MD5Update(context,PADDING,padlen);
MD5Update(context,bits,8);
MD5Encode(digest,context->state,16);
}
voidMD5Encode(unsignedchar*output,unsignedint*input,unsignedintlen)
{
unsignedinti=0,j=0;
while(j<len)
{
output[j]=input[i]&0xFF;
output[j+1]=(input[i]>>8)&0xFF;
output[j+2]=(input[i]>>16)&0xFF;
output[j+3]=(input[i]>>24)&0xFF;
i++;
j+=4;
}
}
voidMD5Decode(unsignedint*output,unsignedchar*input,unsignedintlen)
{
unsignedinti=0,j=0;
while(j<len)
{
output[i]=(input[j])|
(input[j+1]<<8)|
(input[j+2]<<16)|
(input[j+3]<<24);
i++;
j+=4;
}
}
voidMD5Transform(unsignedintstate[4],unsignedcharblock[64])
{
unsignedinta=state[0];
unsignedintb=state[1];
unsignedintc=state[2];
unsignedintd=state[3];
unsignedintx[64];
MD5Decode(x,block,64);
FF(a,b,c,d,x[0],7,0xd76aa478);/*1*/
FF(d,a,b,c,x[1],12,0xe8c7b756);/*2*/
FF(c,d,a,b,x[2],17,0x242070db);/*3*/
FF(b,c,d,a,x[3],22,0xc1bdceee);/*4*/
FF(a,b,c,d,x[4],7,0xf57c0faf);/*5*/
FF(d,a,b,c,x[5],12,0x4787c62a);/*6*/
FF(c,d,a,b,x[6],17,0xa8304613);/*7*/
FF(b,c,d,a,x[7],22,0xfd469501);/*8*/
FF(a,b,c,d,x[8],7,0x698098d8);/*9*/
FF(d,a,b,c,x[9],12,0x8b44f7af);/*10*/
FF(c,d,a,b,x[10],17,0xffff5bb1);/*11*/
FF(b,c,d,a,x[11],22,0x895cd7be);/*12*/
FF(a,b,c,d,x[12],7,0x6b901122);/*13*/
FF(d,a,b,c,x[13],12,0xfd987193);/*14*/
FF(c,d,a,b,x[14],17,0xa679438e);/*15*/
FF(b,c,d,a,x[15],22,0x49b40821);/*16*/

/*Round2*/
GG(a,b,c,d,x[1],5,0xf61e2562);/*17*/
GG(d,a,b,c,x[6],9,0xc040b340);/*18*/
GG(c,d,a,b,x[11],14,0x265e5a51);/*19*/
GG(b,c,d,a,x[0],20,0xe9b6c7aa);/*20*/
GG(a,b,c,d,x[5],5,0xd62f105d);/*21*/
GG(d,a,b,c,x[10],9,0x2441453);/*22*/
GG(c,d,a,b,x[15],14,0xd8a1e681);/*23*/
GG(b,c,d,a,x[4],20,0xe7d3fbc8);/*24*/
GG(a,b,c,d,x[9],5,0x21e1cde6);/*25*/
GG(d,a,b,c,x[14],9,0xc33707d6);/*26*/
GG(c,d,a,b,x[3],14,0xf4d50d87);/*27*/
GG(b,c,d,a,x[8],20,0x455a14ed);/*28*/
GG(a,b,c,d,x[13],5,0xa9e3e905);/*29*/
GG(d,a,b,c,x[2],9,0xfcefa3f8);/*30*/
GG(c,d,a,b,x[7],14,0x676f02d9);/*31*/
GG(b,c,d,a,x[12],20,0x8d2a4c8a);/*32*/

/*Round3*/
HH(a,b,c,d,x[5],4,0xfffa3942);/*33*/
HH(d,a,b,c,x[8],11,0x8771f681);/*34*/
HH(c,d,a,b,x[11],16,0x6d9d6122);/*35*/
HH(b,c,d,a,x[14],23,0xfde5380c);/*36*/
HH(a,b,c,d,x[1],4,0xa4beea44);/*37*/
HH(d,a,b,c,x[4],11,0x4bdecfa9);/*38*/
HH(c,d,a,b,x[7],16,0xf6bb4b60);/*39*/
HH(b,c,d,a,x[10],23,0xbebfbc70);/*40*/
HH(a,b,c,d,x[13],4,0x289b7ec6);/*41*/
HH(d,a,b,c,x[0],11,0xeaa127fa);/*42*/
HH(c,d,a,b,x[3],16,0xd4ef3085);/*43*/
HH(b,c,d,a,x[6],23,0x4881d05);/*44*/
HH(a,b,c,d,x[9],4,0xd9d4d039);/*45*/
HH(d,a,b,c,x[12],11,0xe6db99e5);/*46*/
HH(c,d,a,b,x[15],16,0x1fa27cf8);/*47*/
HH(b,c,d,a,x[2],23,0xc4ac5665);/*48*/

/*Round4*/
II(a,b,c,d,x[0],6,0xf4292244);/*49*/
II(d,a,b,c,x[7],10,0x432aff97);/*50*/
II(c,d,a,b,x[14],15,0xab9423a7);/*51*/
II(b,c,d,a,x[5],21,0xfc93a039);/*52*/
II(a,b,c,d,x[12],6,0x655b59c3);/*53*/
II(d,a,b,c,x[3],10,0x8f0ccc92);/*54*/
II(c,d,a,b,x[10],15,0xffeff47d);/*55*/
II(b,c,d,a,x[1],21,0x85845dd1);/*56*/
II(a,b,c,d,x[8],6,0x6fa87e4f);/*57*/
II(d,a,b,c,x[15],10,0xfe2ce6e0);/*58*/
II(c,d,a,b,x[6],15,0xa3014314);/*59*/
II(b,c,d,a,x[13],21,0x4e0811a1);/*60*/
II(a,b,c,d,x[4],6,0xf7537e82);/*61*/
II(d,a,b,c,x[11],10,0xbd3af235);/*62*/
II(c,d,a,b,x[2],15,0x2ad7d2bb);/*63*/
II(b,c,d,a,x[9],21,0xeb86d391);/*64*/
state[0]+=a;
state[1]+=b;
state[2]+=c;
state[3]+=d;
}

md5函数测试代码文件

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include"md5.h"

intmain(intargc,char*argv[])
{
MD5_CTXmd5;
MD5Init(&md5);
inti;
unsignedcharencrypt[]="admin";//21232f297a57a5a743894a0e4a801fc3
unsignedchardecrypt[16];
MD5Update(&md5,encrypt,strlen((char*)encrypt));
MD5Final(&md5,decrypt);
printf("加密前:%s\n加密后:",encrypt);
for(i=0;i<16;i++)
{
printf("%02x",decrypt[i]);
}

getchar();

return0;
}

MD5加密常用字符

7a57a5a743894a0eadmin(16位MD5小写加密)
972130B75066C825ADMIN(16位MD5大写加密)
21232f297a57a5a743894a0e4a801fc3admin(32位MD5小写加密)
73ACD9A5972130B75066C82595A1FAE3ADMIN(32位MD5大写加密)
49ba59abbe56e057123456(16位MD5小写加密)
e10adc3949ba59abbe56e057f20f883e123456(32位MD5小写加密)
469e80d32c0559f8admin888(16位MD5小写加密)
2299413865C28A35ADMIN888(16位MD5大写加密)
7fef6171469e80d32c0559f88b377245admin888(32位MD5小写加密)
A1F63A962299413865C28A3593D359B0ADMIN888(32位MD5大写加密)

PS.md5知识扫盲

MD5：是一个具体的算法,散列算法，哈西算法，但非加密算法（因为没有密钥），可用于加密（不可逆）
MD5是一种单向散列函数，单向散列函数的作用是将任何长度的一段数据散列成固定长度。常用于生成消息认证码等等，可以与非对称算法一起用于数字签名。
标准见http://www.ietf.org/rfc/rfc1321.txt
MD5好象被国内的一个教授破解了,顺便给大家一个地址http://www.cmd5.com/,有时候应该会很方便的.:)