example.c

来自「加解密包」· C语言 代码 · 共 90 行

/*  
    Time-stamp: <example1.c - Sun 8/17/2003 13:38:57 by tony>
    
    Contact: Tony Song

    revision : 1.3.0 

    This sample code works on Solaris 2.6 and above, Linux, Win32
    Dependency: stringencrypt.h, lib_cstr_xxx.a
    
    purpose:  explain the usage of the following functions:

    int strEncrypt(char *passwd, char *clearText, char *encryptedData)
    int strDecrypt(char *passwd, char *cipherText, char *decryptedData)
*/

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

#include "stringencrypt.h"

void usage(void);

/*******************  Perform encrypt operation *******************/
int encrypt (char *passwd, char *ClearText) {
  char EncryptedData[1024];
  int ret;

  /* User program should calcuate the length
     of input clear text to avoid buffer overflow;
     for demo purpose only, we use fixed length*/

  ret = strEncrypt(passwd,ClearText,EncryptedData);
  if ( ret != 0 ) {/* failed */
    printf("The string encrypt failed; Error #:[%d]!\n",ret);
    return -1;
  }
  
  printf("the cipher text length is %d\n",strlen(EncryptedData));
  printf(">>>: [%s] | [%s] | [%s]\n",passwd, ClearText, EncryptedData);
  return 0;
}

/*******************  Perform decrypt operation *******************/
int decrypt (char *passwd, char *EncryptedData) {
  char clearText[1024];
  int ret;

  ret = strDecrypt(passwd,EncryptedData,clearText);

  printf("return value=%d\n", ret);

  if ( ret != 0 ) {/* failed */
    printf("The string decrypt failed!\n");
    return -1;
  }
  printf("the length of clear text is %d\n",strlen(clearText));
  printf(">>>: [%s] | [%s] | [%s]\n",passwd, clearText, EncryptedData);

  return 0;
}

int main(int argc, char *argv[])
{
  if ( argc < 4 ) {
    usage();
    exit(0);
  }
  
  if (strcmp(argv[1], "E") == 0) {
    printf("This is the passwd:[%s]\n",argv[2]);
    return encrypt(argv[2], argv[3]); 
  } else if (strcmp(argv[1], "D") == 0) {
    return decrypt(argv[2], argv[3]);
  } else {
    usage();
  }
  return 0;
}

  void usage(void)
{
  printf(" Usage:\n\n");
  printf(" example E passwd string   ;Encrypt the clear text.\n");
  printf(" example D passwd string   ;Decrypt the cipher text.\n");
  
  return;
}