C语言生成MD5校验码

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作者：super_bert@csdn

C语言生成MD5校验码源码，从Linux命令源码md5sum移植，MS Windows VS2010环境可用。

头文件md5.h

#ifndef MD5_H#define MD5_H#ifdef __alphatypedef unsigned int uint32;#elsetypedef unsigned long uint32;#endif#define FOPRTXT "r"struct MD5Context {uint32 buf[4];uint32 bits[2];unsigned char in[64];};void MD5Init(struct MD5Context *context);void MD5Update(struct MD5Context *context, unsigned char const *buf, unsigned len);void MD5Final(unsigned char digest[16], struct MD5Context *context);void MD5Transform(uint32 buf[4], uint32 const in[16]);/* * This is needed to make RSAREF happy on some MS-DOS compilers. */typedef struct MD5Context MD5_CTX;/*add by super bert 2014-09-29*///生成文件MD5int mdfile(FILE *fp, unsigned char *digest);int md5sum(const char *file, char *digest );void print_digest(unsigned char *p, char *md5code);#endif /* !MD5_H */

源文件md5.cpp

/* * This code implements the MD5 message-digest algorithm. * The algorithm is due to Ron Rivest.  This code was * written by Colin Plumb in 1993, no copyright is claimed. * This code is in the public domain; do with it what you wish. * * Equivalent code is available from RSA Data Security, Inc. * This code has been tested against that, and is equivalent, * except that you don't need to include two pages of legalese * with every copy. * * To compute the message digest of a chunk of bytes, declare an * MD5Context structure, pass it to MD5Init, call MD5Update as * needed on buffers full of bytes, and then call MD5Final, which * will fill a supplied 16-byte array with the digest. */#include "stdafx.h"#include <string.h>/* for memcpy() */#include "md5.h"void byteReverse(unsigned char *buf, unsigned longs);enum { UNKNOWN, MSB1st, LSB1st } byteOrder = UNKNOWN;void setByteOrder(void) {union {unsigned short int usi;unsigned char uc[2];} w;w.usi = 0x1234;if (w.uc[0] == 0x12)byteOrder = MSB1st;elsebyteOrder = LSB1st;}#ifndef ASM_MD5void byteReverse(unsigned char *buf, unsigned longs){    uint32 t;    if (byteOrder == UNKNOWN)setByteOrder();    if (byteOrder == LSB1st)return;    do {t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |    ((unsigned) buf[1] << 8 | buf[0]);*(uint32 *) buf = t;buf += 4;    } while (--longs);}#endif/* * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious * initialization constants. */void MD5Init(struct MD5Context *ctx){    ctx->buf[0] = 0x67452301;    ctx->buf[1] = 0xefcdab89;    ctx->buf[2] = 0x98badcfe;    ctx->buf[3] = 0x10325476;    ctx->bits[0] = 0;    ctx->bits[1] = 0;}/* * Update context to reflect the concatenation of another buffer full * of bytes. */void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len){    uint32 t;    /* Update bitcount */    t = ctx->bits[0];    if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)ctx->bits[1]++;/* Carry from low to high */    ctx->bits[1] += len >> 29;    t = (t >> 3) & 0x3f;/* Bytes already in shsInfo->data */    /* Handle any leading odd-sized chunks */    if (t) {unsigned char *p = (unsigned char *) ctx->in + t;t = 64 - t;if (len < t) {    memcpy(p, buf, len);    return;}memcpy(p, buf, t);byteReverse(ctx->in, 16);MD5Transform(ctx->buf, (uint32 *) ctx->in);buf += t;len -= t;    }    /* Process data in 64-byte chunks */    while (len >= 64) {memcpy(ctx->in, buf, 64);byteReverse(ctx->in, 16);MD5Transform(ctx->buf, (uint32 *) ctx->in);buf += 64;len -= 64;    }    /* Handle any remaining bytes of data. */    memcpy(ctx->in, buf, len);}/* * Final wrapup - pad to 64-byte boundary with the bit pattern  * 1 0* (64-bit count of bits processed, MSB-first) */void MD5Final(unsigned char digest[16], struct MD5Context *ctx){    unsigned count;    unsigned char *p;    /* Compute number of bytes mod 64 */    count = (ctx->bits[0] >> 3) & 0x3F;    /* Set the first char of padding to 0x80.  This is safe since there is       always at least one byte free */    p = ctx->in + count;    *p++ = 0x80;    /* Bytes of padding needed to make 64 bytes */    count = 64 - 1 - count;    /* Pad out to 56 mod 64 */    if (count < 8) {/* Two lots of padding:  Pad the first block to 64 bytes */memset(p, 0, count);byteReverse(ctx->in, 16);MD5Transform(ctx->buf, (uint32 *) ctx->in);/* Now fill the next block with 56 bytes */memset(ctx->in, 0, 56);    } else {/* Pad block to 56 bytes */memset(p, 0, count - 8);    }    byteReverse(ctx->in, 14);    /* Append length in bits and transform */    ((uint32 *) ctx->in)[14] = ctx->bits[0];    ((uint32 *) ctx->in)[15] = ctx->bits[1];    MD5Transform(ctx->buf, (uint32 *) ctx->in);    byteReverse((unsigned char *) ctx->buf, 4);    memcpy(digest, ctx->buf, 16);    memset(ctx, 0, sizeof(ctx));/* In case it's sensitive */}#ifndef ASM_MD5/* The four core functions - F1 is optimized somewhat *//* #define F1(x, y, z) (x & y | ~x & z) */#define F1(x, y, z) (z ^ (x & (y ^ z)))#define F2(x, y, z) F1(z, x, y)#define F3(x, y, z) (x ^ y ^ z)#define F4(x, y, z) (y ^ (x | ~z))/* This is the central step in the MD5 algorithm. */#define MD5STEP(f, w, x, y, z, data, s) \( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )/* * The core of the MD5 algorithm, this alters an existing MD5 hash to * reflect the addition of 16 longwords of new data.  MD5Update blocks * the data and converts bytes into longwords for this routine. */void MD5Transform(uint32 buf[4], uint32 const in[16]){    register uint32 a, b, c, d;    a = buf[0];    b = buf[1];    c = buf[2];    d = buf[3];    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);    buf[0] += a;    buf[1] += b;    buf[2] += c;    buf[3] += d;}/*add by super bert 2014-09-29*//*生成文件MD5 - 修改版*/int mdfile(FILE *fp, unsigned char *digest){unsigned char buf[100];MD5_CTX ctx;int n;MD5Init(&ctx);/*first step*//*读取文件前100byte*/n = fread(buf, 1, sizeof(buf), fp);MD5Update(&ctx, buf, n);/*second step*//*读取文件末尾100byte*/fseek(fp, -100L, SEEK_END);n = fread(buf, 1, sizeof(buf), fp);MD5Update(&ctx, buf, n);MD5Final(digest, &ctx);if (ferror(fp)) {return -1;}return 0;}/*add by super bert 2014-10-08*/int md5sum(const char *file, char *md5code ){unsigned char digest[16] = {0};FILE *fp = fopen(file, FOPRTXT);if (fp == NULL) {         return -1;}                if (mdfile(fp, digest)) {Printf("md5sum error!\n");fclose(fp);return -1;} print_digest(digest, md5code);fclose(fp);return 0;}void print_digest(unsigned char *p, char *md5code){int i;char str[3];//char md5code[33];                  //strcpy(md5code,"");//memset(md5code, 0x00, sizeof(md5code));for (i = 0; i < 16; ++i){//printf("%02x", *p++);sprintf(str,"%02x", *p++);strcat(md5code,str);}}#endif