BASE64编码

  
    

   
     //
   
      Base 64 encoder / decoder
   
     

   
     
AnsiString Base64Encoder(AnsiString slToEnc)

 {

 
   
     //
   
     The Base64 Table
   
     

   
     
 
   
     const
   
      
   
     char
   
      Base64Table[
   
     64
   
     ]
   
     =
   
     

 
   
     "
   
     ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/
   
     "
   
     ;

 
   
     char
   
      
   
     *
   
      buftoenc 
   
     =
   
      slToEnc.c_str();

 
   
     int
   
      bufsize 
   
     =
   
      slToEnc.Length() 
   
     +
   
      
   
     1
   
     ;

 
   
     char
   
      
   
     *
   
      encbuf 
   
     =
   
      
   
     new
   
      
   
     char
   
     [slToEnc.Length() 
   
     *
   
      
   
     5
   
     ];

 encbuf[
   
     0
   
     ] 
   
     =
   
      
   
     '
   
     \0
   
     '
   
     ; 
   
     int
   
      ilStrLen 
   
     =
   
      
   
     -
   
     1
   
     ;

 
   
     int
   
      i
   
     =
   
     0
   
     ; 
   
     int
   
      b64byte[
   
     5
   
     ];

 unsigned 
   
     char
   
      
   
     *
   
     buftemp;

 AnsiString slRetVal 
   
     =
   
      EmptyStr;





 buftemp
   
     =
   
     (unsigned 
   
     char
   
      
   
     *
   
     )malloc(bufsize
   
     +
   
     2
   
     );

 strcpy(buftemp,buftoenc);

 
   
     if
   
      (fmod(bufsize,
   
     3
   
     )
   
     ==
   
     1
   
     )

 {

 buftemp[bufsize]
   
     =
   
     '
   
     \0
   
     '
   
     ;

 buftemp[bufsize
   
     +
   
     1
   
     ]
   
     =
   
     '
   
     \0
   
     '
   
     ;

 }

 
   
     if
   
      (fmod(bufsize,
   
     3
   
     )
   
     ==
   
     2
   
     )buftemp[bufsize]
   
     =
   
     '
   
     \0
   
     '
   
     ;

 
   
     while
   
      (i
   
     <
   
     bufsize)

 {

 b64byte[
   
     0
   
     ]
   
     =
   
     buftemp[i]
   
     >>
   
     2
   
     ;

 b64byte[
   
     1
   
     ]
   
     =
   
     ((buftemp[i]
   
     &
   
     3
   
     )
   
     <<
   
     4
   
     )
   
     |
   
     (buftemp[i
   
     +
   
     1
   
     ]
   
     >>
   
     4
   
     );

 b64byte[
   
     2
   
     ]
   
     =
   
     ((buftemp[i
   
     +
   
     1
   
     ]
   
     &
   
     0x0F
   
     )
   
     <<
   
     2
   
     )
   
     |
   
     (buftemp[i
   
     +
   
     2
   
     ]
   
     >>
   
     6
   
     );

 b64byte[
   
     3
   
     ]
   
     =
   
     buftemp[i
   
     +
   
     2
   
     ]
   
     &
   
     0x3F
   
     ;

 encbuf[i
   
     +
   
     (i
   
     /
   
     3
   
     )]
   
     =
   
     Base64Table[b64byte[
   
     0
   
     ]];

 encbuf[i
   
     +
   
     (i
   
     /
   
     3
   
     )
   
     +
   
     1
   
     ]
   
     =
   
     Base64Table[b64byte[
   
     1
   
     ]];

 encbuf[i
   
     +
   
     (i
   
     /
   
     3
   
     )
   
     +
   
     2
   
     ]
   
     =
   
     Base64Table[b64byte[
   
     2
   
     ]];

 encbuf[i
   
     +
   
     (i
   
     /
   
     3
   
     )
   
     +
   
     3
   
     ]
   
     =
   
     Base64Table[b64byte[
   
     3
   
     ]];

 i
   
     +=
   
     3
   
     ;

 }

 free(buftemp);





 
   
     if
   
      (fmod(bufsize,
   
     3
   
     )
   
     ==
   
     0
   
     ) ilStrLen 
   
     =
   
      bufsize
   
     *
   
     8
   
     /
   
     6
   
     ;

 
   
     else
   
      
   
     if
   
      (fmod(bufsize,
   
     3
   
     )
   
     ==
   
     1
   
     ) ilStrLen 
   
     =
   
      ((bufsize
   
     +
   
     2
   
     )
   
     *
   
     8
   
     /
   
     6
   
     )
   
     -
   
     2
   
     ;

 
   
     else
   
      
   
     if
   
      (fmod(bufsize,
   
     3
   
     )
   
     ==
   
     2
   
     ) ilStrLen 
   
     =
   
      ((bufsize
   
     +
   
     1
   
     )
   
     *
   
     8
   
     /
   
     6
   
     )
   
     -
   
     1
   
     ;

 
   
     else
   
      ilStrLen 
   
     =
   
      
   
     -
   
     1
   
     ;

 
   
     if
   
     (ilStrLen
   
     >
   
      
   
     0
   
     ) slRetVal 
   
     =
   
      AnsiString(encbuf).SubString(
   
     1
   
     , ilStrLen);

 
   
     if
   
     (encbuf 
   
     !=
   
      NULL) { delete encbuf; encbuf 
   
     =
   
      NULL; }



 
   
     return
   
      slRetVal;

 }





 
   
     //
   
     -----------------------------------------------------------------------
   
     

   
     

 AnsiString Base64Decoder(AnsiString slToDec)
 {

 
   
     //
   
     Base64 Table
   
     

   
      
   
     const
   
      
   
     char
   
      Base64Table[
   
     64
   
     ]
   
     =
   
     

 
   
     "
   
     ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/
   
     "
   
     ;

 
   
     char
   
      
   
     *
   
      buftodec 
   
     =
   
      slToDec.c_str();

 
   
     int
   
      bufsize 
   
     =
   
      slToDec.Length() 
   
     +
   
      
   
     1
   
     ;

 
   
     char
   
      
   
     *
   
      decbuf 
   
     =
   
      
   
     new
   
      
   
     char
   
     [slToDec.Length() 
   
     *
   
      
   
     5
   
     ];

 decbuf[
   
     0
   
     ] 
   
     =
   
      
   
     '
   
     \0
   
     '
   
     ; 
   
     int
   
      ilStrLen 
   
     =
   
      
   
     -
   
     1
   
     ;

 AnsiString slRetVal 
   
     =
   
      EmptyStr;



 
   
     int
   
      i
   
     =
   
     0
   
     ; unsigned 
   
     char
   
      binbyte[
   
     4
   
     ];

 
   
     int
   
      cpos[
   
     5
   
     ]; unsigned 
   
     char
   
      
   
     *
   
     buftemp;



 buftemp
   
     =
   
     (unsigned 
   
     char
   
      
   
     *
   
     )malloc(bufsize);

 strcpy(buftemp,buftodec);

 
   
     if
   
      (fmod(bufsize,
   
     4
   
     )
   
     ==
   
     1
   
     )

 {

 buftemp[bufsize]
   
     =
   
     '
   
     \0
   
     '
   
     ;

 buftemp[bufsize
   
     +
   
     1
   
     ]
   
     =
   
     '
   
     \0
   
     '
   
     ;

 buftemp[bufsize
   
     +
   
     2
   
     ]
   
     =
   
     '
   
     \0
   
     '
   
     ;

 }

 
   
     if
   
      (fmod(bufsize,
   
     4
   
     )
   
     ==
   
     2
   
     )

 {

 buftemp[bufsize]
   
     =
   
     '
   
     \0
   
     '
   
     ;

 buftemp[bufsize
   
     +
   
     1
   
     ]
   
     =
   
     '
   
     \0
   
     '
   
     ;

 }

 
   
     if
   
      (fmod(bufsize,
   
     4
   
     )
   
     ==
   
     3
   
     )buftemp[bufsize]
   
     =
   
     '
   
     \0
   
     '
   
     ;

 
   
     while
   
      (i
   
     <
   
     bufsize)

 {

 cpos[
   
     0
   
     ]
   
     =
   
     strchr(Base64Table,buftemp[i])
   
     -
   
     Base64Table;

 cpos[
   
     1
   
     ]
   
     =
   
     strchr(Base64Table,buftemp[i
   
     +
   
     1
   
     ])
   
     -
   
     Base64Table;

 cpos[
   
     2
   
     ]
   
     =
   
     strchr(Base64Table,buftemp[i
   
     +
   
     2
   
     ])
   
     -
   
     Base64Table;

 cpos[
   
     3
   
     ]
   
     =
   
     strchr(Base64Table,buftemp[i
   
     +
   
     3
   
     ])
   
     -
   
     Base64Table;

 binbyte[
   
     0
   
     ]
   
     =
   
     ((cpos[
   
     0
   
     ]
   
     <<
   
     2
   
     )
   
     |
   
     (cpos[
   
     1
   
     ]
   
     >>
   
     4
   
     ));

 binbyte[
   
     1
   
     ]
   
     =
   
     ((cpos[
   
     1
   
     ]
   
     <<
   
     4
   
     )
   
     |
   
     (cpos[
   
     2
   
     ]
   
     >>
   
     2
   
     ));

 binbyte[
   
     2
   
     ]
   
     =
   
     (((cpos[
   
     2
   
     ]
   
     &
   
     0x03
   
     )
   
     <<
   
     6
   
     )
   
     |
   
     (cpos[
   
     3
   
     ]
   
     &
   
     0x3f
   
     ));

 decbuf[i
   
     -
   
     (i
   
     /
   
     4
   
     )]
   
     =
   
     binbyte[
   
     0
   
     ];

 decbuf[i
   
     -
   
     (i
   
     /
   
     4
   
     )
   
     +
   
     1
   
     ]
   
     =
   
     binbyte[
   
     1
   
     ];

 decbuf[i
   
     -
   
     (i
   
     /
   
     4
   
     )
   
     +
   
     2
   
     ]
   
     =
   
     binbyte[
   
     2
   
     ];

 i
   
     +=
   
     4
   
     ;

 }

 free(buftemp);

 
   
     if
   
      (fmod(bufsize,
   
     4
   
     )
   
     ==
   
     0
   
     ) ilStrLen 
   
     =
   
      bufsize
   
     *
   
     6
   
     /
   
     8
   
     ;

 
   
     else
   
      
   
     if
   
      (fmod(bufsize,
   
     4
   
     )
   
     ==
   
     1
   
     ) ilStrLen 
   
     =
   
      ((bufsize
   
     +
   
     3
   
     )
   
     *
   
     6
   
     /
   
     8
   
     )
   
     -
   
     3
   
     ;

 
   
     else
   
      
   
     if
   
      (fmod(bufsize,
   
     4
   
     )
   
     ==
   
     2
   
     ) ilStrLen 
   
     =
   
      ((bufsize
   
     +
   
     2
   
     )
   
     *
   
     6
   
     /
   
     8
   
     )
   
     -
   
     2
   
     ;

 
   
     else
   
      
   
     if
   
      (fmod(bufsize,
   
     4
   
     )
   
     ==
   
     3
   
     ) ilStrLen 
   
     =
   
      ((bufsize
   
     +
   
     1
   
     )
   
     *
   
     6
   
     /
   
     8
   
     )
   
     -
   
     1
   
     ;

 
   
     else
   
      ilStrLen 
   
     =
   
      
   
     -
   
     1
   
     ;

 
   
     if
   
     (ilStrLen
   
     >
   
      
   
     0
   
     ) slRetVal 
   
     =
   
      AnsiString(decbuf).SubString(
   
     1
   
     , ilStrLen);

 
   
     if
   
     (decbuf 
   
     !=
   
      NULL) { delete decbuf; decbuf 
   
     =
   
      NULL; }

 
   
     return
   
      slRetVal;

 }