base64编解码与3des加解密--未完成

/*base64.h*/

#ifndef __BASE64_H__
#define __BASE64_H__
#include   
  
std::string base64_encode(unsigned char const* , unsigned int len);  
std::string base64_decode(std::string const& s); 

#endif

/**
 * \file sm4.h
 */
#ifndef XYSSL_SM4_H
#define XYSSL_SM4_H

#define SM4_ENCRYPT     1
#define SM4_DECRYPT     0

/**
 * \brief          SM4 context structure
 */
typedef struct
{
    int mode;                   /*!<  encrypt/decrypt   */
    unsigned long sk[32];       /*!<  SM4 subkeys       */
}
sm4_context;


#ifdef __cplusplus
extern "C" {
#endif

/**
 * \brief          SM4 key schedule (128-bit, encryption)
 *
 * \param ctx      SM4 context to be initialized
 * \param key      16-byte secret key
 */
void sm4_setkey_enc( sm4_context *ctx, unsigned char key[16] );

/**
 * \brief          SM4 key schedule (128-bit, decryption)
 *
 * \param ctx      SM4 context to be initialized
 * \param key      16-byte secret key
 */
void sm4_setkey_dec( sm4_context *ctx, unsigned char key[16] );

/**
 * \brief          SM4-ECB block encryption/decryption
 * \param ctx      SM4 context
 * \param mode     SM4_ENCRYPT or SM4_DECRYPT
 * \param length   length of the input data
 * \param input    input block
 * \param output   output block
 */
void sm4_crypt_ecb( sm4_context *ctx,
                     int mode,
                     int length,
                     unsigned char *input,
                     unsigned char *output);

/**
 * \brief          SM4-CBC buffer encryption/decryption
 * \param ctx      SM4 context
 * \param mode     SM4_ENCRYPT or SM4_DECRYPT
 * \param length   length of the input data
 * \param iv       initialization vector (updated after use)
 * \param input    buffer holding the input data
 * \param output   buffer holding the output data
 */
void sm4_crypt_cbc( sm4_context *ctx,
                     int mode,
                     int length,
                     unsigned char iv[16],
                     unsigned char *input,
                     unsigned char *output );

#ifdef __cplusplus
}
#endif

#endif /* sm4.h */

#include 
#include 
#include 
#include "sm4.h"
#include "base64.h"

#define SIZE 10250

int main()
{
    char data[] = {"{\"identifierType\":\"1\",\"identifier\":\"66666666666\",\"pushId\":\"66666666666\",\"appType\":\"1\",\"order\":[{\"orderId\":\"0\",\"orderType\":\"1\",\"serviceId\":\"8201\",\"marketId\":\"2\",\"productType\":\"1\",\"stockCode\":\"600000\",\"stockName\":\"浦发银行\",\"price\":\"14\",\"up\":\"1\"},{\"orderId\":\"0\",\"orderType\":\"1\",\"serviceId\":\"8201\",\"marketId\":\"2\",\"productType\":\"1\",\"stockCode\":\"600000\",\"stockName\":\"浦发银行\",\"price\":\"12\",\"up\":\"2\"},{\"orderId\":\"0\",\"orderType\":\"1\",\"serviceId\":\"8202\",\"marketId\":\"2\",\"productType\":\"1\",\"stockCode\":\"600000\",\"stockName\":\"浦发银行\",\"price\":\"0.02\",\"up\":\"1\"},{\"orderId\":\"0\",\"orderType\":\"1\",\"se viceId\":\"8202\",\"marketId\":\"2\",\"productType\":\"1\",\"stockCode\":\"600000\",\"stockNa    me\":\"浦发银行\",\"price\":\"0.02\",\"up\":\"2\"}]}"};    unsigned char key[16] = {1,255,38,94,66,165,29,37,98,192,231,186,13,2,169,201};
    unsigned char *src = (unsigned char *)data;
    size_t srclen = strlen(data);

    unsigned char sm4Src[SIZE * 10];
    std::string base64Src;
    std::string base64Dst;
    std::string sm4StrDst;
    unsigned char sm4Dst[SIZE];
    unsigned char dst[10240];
    char buff[10240] = {0};

/
    sm4_context ctx;
    sm4_setkey_enc(&ctx,key);
    sm4_crypt_ecb(&ctx,SM4_ENCRYPT,srclen,src,sm4Src);
    size_t sm4SrcLen = 16 - srclen % 16 + srclen;
    base64Src = base64_encode(sm4Src,sm4SrcLen);
/
    base64Dst = base64Src;
    sm4StrDst = base64_decode(base64Dst);
    memcpy(sm4Dst,sm4StrDst.c_str(),sm4StrDst.size());
    sm4_setkey_dec(&ctx,key);
    sm4_crypt_ecb(&ctx,SM4_DECRYPT,sm4StrDst.size(),sm4Dst,dst);
    memcpy(buff,dst,sm4StrDst.size());
    buff[sm4StrDst.size()] = 0;

    std::cout << buff << std::endl;

    return 0;
}

#include "base64.h"
#include   
  
static const std::string base64_chars =   
             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"  
             "abcdefghijklmnopqrstuvwxyz"  
             "0123456789+/";  
  
  
static inline bool is_base64(unsigned char c) {   
  return (isalnum(c) || (c == '+') || (c == '/'));  
}  
  
std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {   
  std::string ret;  
  int i = 0;  
  int j = 0;  
  unsigned char char_array_3[3];  
  unsigned char char_array_4[4];  
  
  while (in_len--) {   
    char_array_3[i++] = *(bytes_to_encode++);  
    if (i == 3) {   //每获取三个字节,就进行编码.
      char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;  
      char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);  
      char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);  
      char_array_4[3] = char_array_3[2] & 0x3f;  
  
      for(i = 0; (i <4) ; i++)  
        ret += base64_chars[char_array_4[i]];  //查字典
      i = 0;  
    }   
  }   
  
  if (i)  
  {   
    for(j = i; j < 3; j++)  
      char_array_3[j] = '\0';  
  
    char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;  
    char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);  
    char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);  
    char_array_4[3] = char_array_3[2] & 0x3f;

    for (j = 0; (j < i + 1); j++) //i=1/2:至少编码8/16bit,实际编码12/18bit,产生2/3bytes.
      ret += base64_chars[char_array_4[j]];

    while((i++ < 3))
      ret += '=';

  }

  return ret;

}

std::string base64_decode(std::string const& encoded_string) {
  int in_len = encoded_string.size();
  int i = 0;
  int j = 0;
  int in_ = 0;
  unsigned char char_array_4[4], char_array_3[3];
  std::string ret;

  while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
    char_array_4[i++] = encoded_string[in_]; in_++;
    if (i ==4) {
      for (i = 0; i <4; i++)
        char_array_4[i] = base64_chars.find(char_array_4[i]);

      char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
      char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
      char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

      for (i = 0; (i < 3); i++)
        ret += char_array_3[i];
      i = 0;
    }
  }

  if (i) {
    for (j = i; j <4; j++)
      char_array_4[j] = 0;

    for (j = 0; j <4; j++)
      char_array_4[j] = base64_chars.find(char_array_4[j]);

    char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
    char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
    char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

    for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
  }

  return ret;
}

base64_chars有64位可显示符号,即占6bit,作为字典.

每三个字节为一组(24bit),进行编码:
1,取出第一个6bit,查字典,字典结果为编码.
0xfc:1111 1100 >> 2 == 11 1111
2,取出第二个6bit,查字典,字典结果为编码.
0x03:0000 0011 << 4 == 11 0000
0xf0:1111 0000 >> 4 == 00 1111
3,取出第三个6bit,查字典,字典结果为编码.
0x0f:0000 1111 << 2 == 11 1100
0xc0:1100 0000 >> 6 == 00 0011
4,取出第四个6bit,查字典,字典结果为编码.
0x3f:0011 1111      == 11 1111
如果最后一组只有i=1/2个字节:
补0填充.

i=1 ---8bit需编码
char_arr_3[0]=原值. 
char_arr_3[1]=0.
char_arr_3[2]=0.
编码后:
char_arr_4[0]//编码正常
char_arr_4[1]//编码正常
char_arr_4[2]//编码不应有 赋值'='
char_arr_4[3]//编码不应有 赋值'='

i=2 ---16bit需编码
char_arr_3[0]=原值. 
char_arr_3[1]=原值. 
char_arr_3[2]=0.
编码后:
char_arr_4[0]//编码正常
char_arr_4[1]//编码正常
char_arr_4[2]//编码正常
char_arr_4[3]//编码不应有 赋值'='