c语言md5计算
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#ifdefined(__APPLE__)
#defineCOMMON_DIGEST_FOR_OPENSSL
#include<CommonCrypto/CommonDigest.h>
#defineSHA1CC_SHA1
#else
#include<openssl/md5.h>
#endif
//这是我自己写的函数，用于计算MD5
//参数str：要转换的字符串
//参数lengthL:字符串的长度可以用strlen(str)直接获取参数str的长度
//返回值：MD5字符串
char*str2md5(constchar*str,intlength){
intn;
MD5_CTXc;
unsignedchardigest[16];
char*out=(char*)malloc(33);
MD5_Init(&c);
while(length>0){
if(length>512){
MD5_Update(&c,str,512);
}else{
MD5_Update(&c,str,length);
}
length-=512;
str+=512;
}
MD5_Final(digest,&c);
for(n=0;n<16;++n){
snprintf(&(out[n*2]),16*2,"%02x",(unsignedint)digest[n]);
}
returnout;
}
intmain(intargc,char**argv){
char*output=str2md5("hello",strlen("hello"));
printf("%s ",output);
//上面会输出hello的MD5字符串：
//
free(output);
return0;
}
② 如何用C语言实现MD5算法计算一个文本的消息摘要
MD5是不可能逆向的。
王教授的碰撞法是利用了MD5或者SHA1算法的一个特性，
根据MD5和SHA1等Hash算法的特点，因为他们是任意长度的字符串变成固定长度的摘要信息。
那么这里就有可能发生一个问题，就是不同的字符串在理论上是有可能产生相同的摘要信息。
王教授所谓的碰撞法，碰撞的就是不同的字符串所产生的摘要信息是一样的那些字符串。因此得名碰撞法。
碰撞就是体现在这里。没有什么其它的传神的东西了。根据SHA1和MD5等Hash算法，在设计时候，设计这个算法的人认为不同的字符串要产生相同结果的摘要信息的可能性几乎为零。而王教授则证明了SHA1和MD5等Hash算法产生的摘要信息规则是可以在比较短时间内被破解的。这样一来，原始数据的
Integrity
就被打破了。
所谓的破解，也就是体现在这里。
至于破解工具，下面的地址提供一些免费的破解服务，能破解一些简单的密码，其实都是采用字典或暴力破解。
www.cmd5.com
www.xmd5.org
我有时去破解一些常用的密码，有一定的成功率
③ C语言实现文件传输时用md5加密
你需要先搞一个openssl的库，然后调用相应的md5的函数就好了
④ 求c语言下获取一个字符串MD5值得函数
1. md5.h：
＃pragma once
typedef unsigned long int UINT32;
typedef unsigned short int UINT16;
/× MD5 context. */
typedef struct {
UINT32 state[4]; /× state (ABCD) */
UINT32 count[2]; /× number of bits, molo 2^64 (lsb first) */
unsigned char buffer[64]; /× input buffer */
} MD5_CTX;
void MD5Init (MD5_CTX *);
void MD5Update (MD5_CTX *, unsigned char *, unsigned int);
void MD5Final (unsigned char [16], MD5_CTX *);
——————————————————————————
2. md5.cpp：
＃include "md5.h"
＃include "memory.h"
＃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
static void MD5Transform (UINT32 a[4], unsigned char b[64]);
static void Encode (unsigned char *, UINT32 *, unsigned int);
static void Decode (UINT32 *, unsigned char *, unsigned int);
static unsigned char 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
};
＃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) + (UINT32)(ac);
(a) = ROTATE_LEFT ((a), (s));
(a) += (b);
}
＃define GG(a, b, c, d, x, s, ac) {
(a) += G ((b), (c), (d)) + (x) + (UINT32)(ac);
(a) = ROTATE_LEFT ((a), (s));
(a) += (b);
}
＃define HH(a, b, c, d, x, s, ac) {
(a) += H ((b), (c), (d)) + (x) + (UINT32)(ac);
(a) = ROTATE_LEFT ((a), (s));
(a) += (b);
}
＃define II(a, b, c, d, x, s, ac) {
(a) += I ((b), (c), (d)) + (x) + (UINT32)(ac);
(a) = ROTATE_LEFT ((a), (s));
(a) += (b);
}
void MD5Init (MD5_CTX *context)
{
context->count[0] = context->count[1] = 0;
context->state[0] = 0x67452301;
context->state[1] = 0xefcdab89;
context->state[2] = 0x98badcfe;
context->state[3] = 0x10325476;
}
void MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen)
{
unsigned int i, index, partLen;
index = (unsigned int)((context->count[0] >> 3) & 0x3F);
if ((context->count[0] += ((UINT32)inputLen << 3))
< ((UINT32)inputLen << 3))
context->count[1]++;
context->count[1] += ((UINT32)inputLen >> 29);
partLen = 64 - index;
if (inputLen >= partLen) {
memcpy((unsigned char *)&context->buffer[index], (unsigned char *)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;
memcpy((unsigned char *)&context->buffer[index], (unsigned char *)&input[i],
inputLen-i);
}
void MD5Final (unsigned char digest[16], MD5_CTX * context)
{
unsigned char bits[8];
unsigned int index, padLen;
Encode (bits, context->count, 8);
index = (unsigned int)((context->count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
MD5Update (context, PADDING, padLen);
MD5Update (context, bits, 8);
Encode (digest, context->state, 16);
memset ((unsigned char *)context, 0, sizeof (*context));
}
static void MD5Transform (UINT32 state[4], unsigned char block[64])
{
UINT32 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
Decode (x, block, 64);
/× Round 1 */
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 */
/× Round 2 */
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 */
/× Round 3 */
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 */
/× Round 4 */
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;
memset ((unsigned char *)x, 0, sizeof (x));
}
static void Encode (unsigned char *output, UINT32 *input, unsigned int len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (unsigned char)(input[i] & 0xff);
output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
}
}
static void Decode (UINT32 *output, unsigned char *input, unsigned int len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((UINT32)input[j]) | (((UINT32)input[j+1]) << 8) |
(((UINT32)input[j+2]) << 16) | (((UINT32)input[j+3]) << 24);
}
——————————————————————————
＃include <stdio.h>
＃include <string.h>
＃include "md5.h"
int main ()
{
char tmp[128];
unsigned char digest[16];
MD5_CTX context;
scanf("%s",tmp);
MD5Init (&context);
MD5Update (&context, (unsigned char*)tmp, strlen(tmp));
MD5Final (digest,&context);
printf("MD5Value:");
for(int i=0; i<16; ++i)
{
printf("%02X",digest[i]);
}
printf(" ");
return 0;
}
⑤ C语言求文件MD5的函数用法
C语言没有内置的MD5函数，可以在以下页面找到C语言实现程序和MD5的算法介绍：
http://tools.ietf.org/html/rfc1321
⑥ 求MD5加密算法的C语言源码
（转载） #include <stdio.h> #include <stdlib.h> #include <memory.h> #include <time.h> #include <errno.h> #include <string.h> #include <sys/socket.h> #include <sys/types.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> #include "../md5/md5.h" #define T1 0xd76aa478 #define T2 0xe8c7b756 #define T3 0x242070db #define T4 0xc1bdceee #define T5 0xf57c0faf #define T6 0x4787c62a #define T7 0xa8304613 #define T8 0xfd469501 #define T9 0x698098d8 #define T10 0x8b44f7af #define T11 0xffff5bb1 #define T12 0x895cd7be #define T13 0x6b901122 #define T14 0xfd987193 #define T15 0xa679438e #define T16 0x49b40821 #define T17 0xf61e2562 #define T18 0xc040b340 #define T19 0x265e5a51 #define T20 0xe9b6c7aa #define T21 0xd62f105d #define T22 0x02441453 #define T23 0xd8a1e681 #define T24 0xe7d3fbc8 #define T25 0x21e1cde6 #define T26 0xc33707d6 #define T27 0xf4d50d87 #define T28 0x455a14ed #define T29 0xa9e3e905 #define T30 0xfcefa3f8 #define T31 0x676f02d9 #define T32 0x8d2a4c8a #define T33 0xfffa3942 #define T34 0x8771f681 #define T35 0x6d9d6122 #define T36 0xfde5380c #define T37 0xa4beea44 #define T38 0x4bdecfa9 #define T39 0xf6bb4b60 #define T40 0xbebfbc70 #define T41 0x289b7ec6 #define T42 0xeaa127fa #define T43 0xd4ef3085 #define T44 0x04881d05 #define T45 0xd9d4d039 #define T46 0xe6db99e5 #define T47 0x1fa27cf8 #define T48 0xc4ac5665 #define T49 0xf4292244 #define T50 0x432aff97 #define T51 0xab9423a7 #define T52 0xfc93a039 #define T53 0x655b59c3 #define T54 0x8f0ccc92 #define T55 0xffeff47d #define T56 0x85845dd1 #define T57 0x6fa87e4f #define T58 0xfe2ce6e0 #define T59 0xa3014314 #define T60 0x4e0811a1 #define T61 0xf7537e82 #define T62 0xbd3af235 #define T63 0x2ad7d2bb #define T64 0xeb86d391 static void md5_process(md5_state_t *pms, const md5_byte_t *data /*[64]*/) { md5_word_t a = pms->abcd[0], b = pms->abcd[1], c = pms->abcd[2], d = pms->abcd[3]; md5_word_t t; #ifndef ARCH_IS_BIG_ENDIAN # define ARCH_IS_BIG_ENDIAN 1 /* slower, default implementation */ #endif #if ARCH_IS_BIG_ENDIAN /* * On big-endian machines, we must arrange the bytes in the right * order. (This also works on machines of unknown byte order.) */ md5_word_t X[16]; const md5_byte_t *xp = data; int i; for (i = 0; i < 16; i, xp = 4) X[i] = xp[0] (xp[1] << 8) (xp[2] << 16) (xp[3] << 24); #else /* !ARCH_IS_BIG_ENDIAN */ /* * On little-endian machines, we can process properly aligned data * without ing it. */ md5_word_t xbuf[16]; const md5_word_t *X; if (!((data - (const md5_byte_t *)0) & 3)) { /* data are properly aligned */ X = (const md5_word_t *)data; } else { /* not aligned */ memcpy(xbuf, data, 64); X = xbuf; } #endif #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n)))) /* Round 1. */ /* Let [abcd k s i] denote the operation a = b ((a F(b,c,d) X[k] T[i]) <<< s). */ #define F(x, y, z) (((x) & (y)) | (~(x) & (z))) #define SET(a, b, c, d, k, s, Ti)\ t = a F(b,c,d) X[k] Ti;\ a = ROTATE_LEFT(t, s) b /* Do the following 16 operations. */ SET(a, b, c, d, 0, 7, T1); SET(d, a, b, c, 1, 12, T2); SET(c, d, a, b, 2, 17, T3); SET(b, c, d, a, 3, 22, T4); SET(a, b, c, d, 4, 7, T5); SET(d, a, b, c, 5, 12, T6); SET(c, d, a, b, 6, 17, T7); SET(b, c, d, a, 7, 22, T8); SET(a, b, c, d, 8, 7, T9); SET(d, a, b, c, 9, 12, T10); SET(c, d, a, b, 10, 17, T11); SET(b, c, d, a, 11, 22, T12); SET(a, b, c, d, 12, 7, T13); SET(d, a, b, c, 13, 12, T14); SET(c, d, a, b, 14, 17, T15); SET(b, c, d, a, 15, 22, T16); #undef SET /* Round 2. */ /* Let [abcd k s i] denote the operation a = b ((a G(b,c,d) X[k] T[i]) <<< s). */ #define G(x, y, z) (((x) & (z)) | ((y) & ~(z))) #define SET(a, b, c, d, k, s, Ti)\ t = a G(b,c,d) X[k] Ti;\ a = ROTATE_LEFT(t, s) b /* Do the following 16 operations. */ SET(a, b, c, d, 1, 5, T17); SET(d, a, b, c, 6, 9, T18); SET(c, d, a, b, 11, 14, T19); SET(b, c, d, a, 0, 20, T20); SET(a, b, c, d, 5, 5, T21); SET(d, a, b, c, 10, 9, T22); SET(c, d, a, b, 15, 14, T23); SET(b, c, d, a, 4, 20, T24); SET(a, b, c, d, 9, 5, T25); SET(d, a, b, c, 14, 9, T26); SET(c, d, a, b, 3, 14, T27); SET(b, c, d, a, 8, 20, T28); SET(a, b, c, d, 13, 5, T29); SET(d, a, b, c, 2, 9, T30); SET(c, d, a, b, 7, 14, T31); SET(b, c, d, a, 12, 20, T32); #undef SET
⑦ c语言实现MD5加密算法，出现问题求解
找不到md5.h的头文件 将你的md5.h头文件跟你的c文件放在同一目录下
⑧ VS2013中c语言md5加密函数怎么调用
1、主要就是调用库函数，MD5加密说到底也是函数计算，没有什么思路的问题，了解md5的发明算法，本质是一个数学问题。
2、例程：
#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
源文件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*/
⑨ c语言md5程序里面有文件位操作不懂 达人请进
0x2000 0000在这里是16进制数 转换成十进制数是536870912bit = 67108864 BYTE = 65536 KB = 64MB
/* flen[1]=len/0x20000000; //flen单位是bit */
这行指令做的是 看那个被打开的文件的长度是64兆的多少倍 并且把计算出的结果（倍数）放到array flen[1]里（file length）并且存进去的是个整数 文件长度是个很长的很奇怪的数 除个536870912这么个怪数肯定不会是个整数（至少大多情况下）
所以有了下面这一行指令
/* flen[0]=(len%0x20000000)*8; */
这行指令把file length除64MB这个数的余数提出 并且乘了8（即除以64MB 余数* 8 让BYTE单位变成bit单位） 为程序的后面做运算做铺垫或者准备
并且存在了flen[0]里
这个程序不全 我想提问题的人应该有全的版本 我能给的帮助就这么多 希望能帮到你:)
⑩ 如何对字符串进行MD5加密,用C语言实现,给出源代码和加密函数
/*四个32bits数,用于存放最终计算得到的消息摘要.当消息长度>512bits时,也用于存放每个512bits的中间结果*/ UINT4 state[4]; /*存储原始信息的bits数长度,不包括填充的bits,最长为2^64 bits*/ UINT4 count[2]; /*存放输入的信息的缓冲区,512bits*/ unsigned char buffer[64];} MD5_CTX;static void MD5Transform(UINT4[4], unsigned char[64]); static void Encode(unsigned char *, UINT4 *, unsigned int); static void Decode(UINT4 *, unsigned char *, unsigned int);/*用于bits填充的缓冲区,当欲加密的信息的bits数被512除其余数为448时,需要填充的bits的最大值为512=64*8*/ static unsigned char 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};/*接下来的这几个宏定义是md5算法规定的,就是对信息进行md5加密都要做的运算*/ #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) + (UINT4)(ac);\ (a) = ROTATE_LEFT ((a), (s));\ (a) += (b);\}#define GG(a, b, c, d, x, s, ac) {\ (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac);\ (a) = ROTATE_LEFT ((a), (s));\ (a) += (b);\}#define HH(a, b, c, d, x, s, ac) {\ (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac);\ (a) = ROTATE_LEFT ((a), (s));\ (a) += (b);\}#define II(a, b, c, d, x, s, ac) {\ (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac);\