C语言压缩文件和用MD5算法校验文件完整性的实例教程

SRes SzArEx_Open(CSzArEx *p, ILookInStream *inStream, ISzAlloc *allocMain, ISzAlloc *allocTemp);  SRes SzAr_Extract(   const CSzArEx *p,   ILookInStream *inStream,   UInt32 fileIndex,   UInt32 *blockIndex,   Byte **outBuffer,   size_t *outBufferSize,   size_t *offset,   size_t *outSizeProcessed,   ISzAlloc *allocMain,   ISzAlloc *allocTemp); 

/* 7zMain.c - Test application for 7z Decoder */  #include <stdlib.h> #include <stdio.h> #include <string.h>  #define LOGD printf #define LOGE printf  #include "7zCrc.h" #include "7zFile.h" #include "7zVersion.h"  #include "7zAlloc.h" #include "7zExtract.h" #include "7zIn.h"  int MY_CDECL extract7z(const char* srcFile, const char* dstPath) {   CFileInStream archiveStream;   CLookToRead lookStream;   CSzArEx db;   SRes res;   ISzAlloc allocImp;   ISzAlloc allocTempImp;   char outPath[1024] = { 0 };    LOGD("7z ANSI-C Decoder " MY_VERSION_COPYRIGHT_DATE "/n");    if (InFile_Open(&archiveStream.file, srcFile)) {//open 7z file     LOGE("can not open input file/n");     return 1;   }    FileInStream_CreateVTable(&archiveStream);   LookToRead_CreateVTable(&lookStream, False);    lookStream.realStream = &archiveStream.s;   LookToRead_Init(&lookStream);    allocImp.Alloc = SzAlloc;   allocImp.Free = SzFree;    allocTempImp.Alloc = SzAllocTemp;   allocTempImp.Free = SzFreeTemp;    CrcGenerateTable();    SzArEx_Init(&db);   res = SzArEx_Open(&db, &lookStream.s, &allocImp, &allocTempImp);    if(res == SZ_OK)   {     Int32 i;      UInt32 blockIndex = 0xFFFFFFFF; /* it can have any value before first call (if outBuffer = 0) */     Byte *outBuffer = 0; /* it must be 0 before first call for each new archive. */     size_t outBufferSize = 0; /* it can have any value before first call (if outBuffer = 0) */      LOGD("Total file/directory count[%d]/n", db.db.NumFiles);     for (i = db.db.NumFiles - 1; i >= 0; i--) {       size_t offset;       size_t outSizeProcessed;       CSzFileItem *f = db.db.Files + i;        strcpy(outPath, dstPath);       strcat(outPath, "/");       strcat(outPath, f->Name);        if (f->IsDir) { //dir         LOGD("dir [%s]/n", outPath);         mkdir(outPath);         continue;       }else{ //file         LOGD("file [%s]/n", outPath);         res = SzAr_Extract(&db, &lookStream.s, i, &blockIndex,             &outBuffer, &outBufferSize, &offset, &outSizeProcessed,             &allocImp, &allocTempImp);         if (res != SZ_OK){           break;         }else{           CSzFile outFile;           size_t processedSize;           if (OutFile_Open(&outFile, outPath)) {             LOGE("can not open output file/n");             res = SZ_ERROR_FAIL;             break;           }           processedSize = outSizeProcessed;           if (File_Write(&outFile, outBuffer + offset, &processedSize)               != 0 || processedSize != outSizeProcessed) {             LOGE("can not write output file/n");             res = SZ_ERROR_FAIL;             break;           }           if (File_Close(&outFile)) {             LOGE("can not close output file/n");             res = SZ_ERROR_FAIL;             break;           }         }       }     }     IAlloc_Free(&allocImp, outBuffer);   }   SzArEx_Free(&db, &allocImp);    File_Close(&archiveStream.file);   if (res == SZ_OK)   {     LOGD("Everything is Ok/n");     return 0;   }   if (res == SZ_ERROR_UNSUPPORTED     )     LOGE("decoder doesn't support this archive/n");   else if (res == SZ_ERROR_MEM     )     LOGE("can not allocate memory/n");   else if (res == SZ_ERROR_CRC     )     LOGE("CRC error/n");   else     LOGE("ERROR #%d/n", res);   return 1; }  int main(int numargs, char *args[]) {   return extract7z(args[1], args[2]); } 

#ifndef MD5_H #define MD5_H  #ifdef __cplusplus extern "C" { #endif             /* __cplusplus */  #ifdef HAVE_CONFIG_H # include "config.h" #endif  #ifdef HAVE_STDINT_H   #include <stdint.h>   typedef uint32_t uint32; #else   /* A.Leo.: this wont work on 16 bits platforms ;) */   typedef unsigned uint32; #endif  #define MD5_FILE_BUFFER_LEN 1024  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]);  int getBytesMD5(const unsigned char* src, unsigned int length, char* md5); int getStringMD5(const char* src, char* md5); int getFileMD5(const char* path, char* md5);  /*  * This is needed to make RSAREF happy on some MS-DOS compilers.  */ typedef struct MD5Context MD5_CTX;  #ifdef __cplusplus } #endif             /* __cplusplus */  #endif /* !MD5_H */ 

#include <string.h>    /* for memcpy() */ #include <stdio.h> #include "md5.h"  #ifndef HIGHFIRST #define byteReverse(buf, len)  /* Nothing */ #else void byteReverse(unsigned char *buf, unsigned longs);  #ifndef ASM_MD5 /*  * Note: this code is harmless on little-endian machines.  */ void byteReverse(unsigned char *buf, unsigned longs) {   uint32 t;   do {     t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |     ((unsigned) buf[1] << 8 | buf[0]);     *(uint32 *) buf = t;     buf += 4;   }while (--longs); } #endif #endif  static void putu32(uint32 data, unsigned char *addr) {   addr[0] = (unsigned char) data;   addr[1] = (unsigned char) (data >> 8);   addr[2] = (unsigned char) (data >> 16);   addr[3] = (unsigned char) (data >> 24); }  /*  * 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];   putu32(ctx->bits[0], ctx->in + 56);   putu32(ctx->bits[1], ctx->in + 60);    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; }  /*  * get MD5 of a byte buffer  */ int getBytesMD5(const unsigned char* src, unsigned int length, char* md5) {   unsigned char i = 0;   unsigned char md5Bytes[16] = { 0 };   MD5_CTX context;   if (src == NULL || md5 == NULL)   {     return -1;   }   MD5Init(&context);   MD5Update(&context, src, length);   MD5Final(md5Bytes, &context);   for (i = 0; i < 16; i++) {     sprintf(md5, "%02X", md5Bytes[i]);     md5 += 2;   }   *md5 = '/0';   return 0; }  /*  * get MD5 for a string  */ int getStringMD5(const char* src, char* md5) {   return getBytesMD5((unsigned char*) src, strlen((char*) src), md5); }  /**  * get MD5 of a file  */ int getFileMD5(const char* path, char* md5) {   FILE* fp = NULL;   unsigned char buffer[MD5_FILE_BUFFER_LEN] = { 0 };   int count = 0;   MD5_CTX context;   unsigned char md5Bytes[16] = { 0 };   int i;   if (path == NULL || md5 == NULL) {     return -1;   }   fp = fopen(path, "rb");   if (fp == NULL) {     return -1;   }   MD5Init(&context);   while ((count = fread(buffer, 1, MD5_FILE_BUFFER_LEN, fp)) > 0) {     MD5Update(&context, buffer, count);   }   MD5Final(md5Bytes, &context);   for (i = 0; i < 16; i++) {     sprintf(md5, "%02X", md5Bytes[i]);     md5 += 2;   }   *md5 = '/0';   return 0; }  #endif 

#include <stdio.h> #include <string.h>  #include "md5.h"  int main(int c, char** v){   char buffer[128];   getStringMD5("hello world", buffer);   printf("%s/n", buffer);   getFileMD5("hello.pdf", buffer);   printf("%s/n", buffer);   return 0; }