Base64.hpp Source File

00001 /*
00002  * Copyright 2001,2004 The Apache Software Foundation.
00003  * 
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  * 
00008  *      http://www.apache.org/licenses/LICENSE-2.0
00009  * 
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 /*
00018  * $Id: Base64.hpp,v 1.13 2004/09/08 13:56:21 peiyongz Exp $
00019  */
00020 
00021 #ifndef BASE64_HPP
00022 #define BASE64_HPP
00023 
00024 #include <xercesc/util/XercesDefs.hpp>
00025 #include <xercesc/util/XMLUniDefs.hpp>
00026 #include <xercesc/framework/MemoryManager.hpp>
00027 
00028 XERCES_CPP_NAMESPACE_BEGIN
00029 
00030 //
00031 // This class provides encode/decode for RFC 2045 Base64 as
00032 // defined by RFC 2045, N. Freed and N. Borenstein.
00033 // RFC 2045: Multipurpose Internet Mail Extensions (MIME)
00034 // Part One: Format of Internet Message Bodies. Reference
00035 // 1996 Available at: http://www.ietf.org/rfc/rfc2045.txt
00036 // This class is used by XML Schema binary format validation
00037 //
00038 //
00039 class  Base64
00040 {
00041 public :
00042 
00043     enum Conformance
00044     {
00045         Conf_RFC2045
00046       , Conf_Schema
00047     };
00048 
00050 
00069     static XMLByte* encode(const XMLByte* const inputData
00070                          , const unsigned int   inputLength
00071                          , unsigned int*        outputLength
00072                          , MemoryManager* const memMgr = 0);
00073 
00092     static XMLByte* decode(
00093                            const XMLByte*        const   inputData
00094                          ,       unsigned int*           decodedLength
00095                          ,       MemoryManager*  const   memMgr = 0
00096                          ,       Conformance             conform = Conf_RFC2045
00097                           );
00098 
00117     static XMLCh* decode(
00118                          const XMLCh*          const    inputData
00119                        ,       unsigned int*            decodedLength
00120                        ,       MemoryManager*  const    memMgr = 0
00121                        ,       Conformance              conform = Conf_RFC2045
00122                         );
00123 
00136     static int getDataLength(
00137                              const XMLCh*         const  inputData
00138                             ,      MemoryManager* const  memMgr = 0
00139                             ,      Conformance           conform = Conf_RFC2045
00140                              );
00141 
00143 
00159     static XMLCh* getCanonicalRepresentation
00160                   (
00161                       const XMLCh*          const inputData
00162                     ,       MemoryManager*  const memMgr = 0
00163                     ,       Conformance           conform = Conf_RFC2045
00164                   );
00165 
00166 private :
00167 
00168     // -----------------------------------------------------------------------
00169     //  Helper methods
00170     // -----------------------------------------------------------------------
00171 
00172     static XMLByte* decode(
00173                            const XMLByte*        const   inputData
00174                          ,       unsigned int*           outputLength
00175                          ,       XMLByte*&               canRepData
00176                          ,       MemoryManager*  const   memMgr = 0
00177                          ,       Conformance             conform = Conf_RFC2045
00178                           );
00179 
00180     static void init();
00181 
00182     static bool isData(const XMLByte& octet);
00183     static bool isPad(const XMLByte& octet);
00184 
00185     static XMLByte set1stOctet(const XMLByte&, const XMLByte&);
00186     static XMLByte set2ndOctet(const XMLByte&, const XMLByte&);
00187     static XMLByte set3rdOctet(const XMLByte&, const XMLByte&);
00188 
00189     static void split1stOctet(const XMLByte&, XMLByte&, XMLByte&);
00190     static void split2ndOctet(const XMLByte&, XMLByte&, XMLByte&);
00191     static void split3rdOctet(const XMLByte&, XMLByte&, XMLByte&);
00192 
00193     // -----------------------------------------------------------------------
00194     //  Unimplemented constructors and operators
00195     // -----------------------------------------------------------------------
00196     Base64();
00197     Base64(const Base64&);
00198 
00199     // -----------------------------------------------------------------------
00200     //  Private data members
00201     //
00202     //  base64Alphabet
00203     //     The Base64 alphabet (see RFC 2045).
00204     //
00205     //  base64Padding
00206     //     Padding character (see RFC 2045).
00207     //
00208     //  base64Inverse
00209     //     Table used in decoding base64.
00210     //
00211     //  isInitialized
00212     //     Set once base64Inverse is initalized.
00213     //
00214     //  quadsPerLine
00215     //     Number of quadruplets per one line. The encoded output
00216     //     stream must be represented in lines of no more
00217     //     than 19 quadruplets each.
00218     //
00219     // -----------------------------------------------------------------------
00220 
00221     static const XMLByte  base64Alphabet[];
00222     static const XMLByte  base64Padding;
00223 
00224     static XMLByte  base64Inverse[];
00225     static bool  isInitialized;
00226 
00227     static const unsigned int  quadsPerLine;
00228 };
00229 
00230 // -----------------------------------------------------------------------
00231 //  Helper methods
00232 // -----------------------------------------------------------------------
00233 inline bool Base64::isPad(const XMLByte& octet)
00234 {
00235     return ( octet == base64Padding );
00236 }
00237 
00238 inline XMLByte Base64::set1stOctet(const XMLByte& b1, const XMLByte& b2)
00239 {
00240     return (( b1 << 2 ) | ( b2 >> 4 ));
00241 }
00242 
00243 inline XMLByte Base64::set2ndOctet(const XMLByte& b2, const XMLByte& b3)
00244 {
00245     return (( b2 << 4 ) | ( b3 >> 2 ));
00246 }
00247 
00248 inline XMLByte Base64::set3rdOctet(const XMLByte& b3, const XMLByte& b4)
00249 {
00250     return (( b3 << 6 ) | b4 );
00251 }
00252 
00253 inline void Base64::split1stOctet(const XMLByte& ch, XMLByte& b1, XMLByte& b2) {
00254     b1 = ch >> 2;
00255     b2 = ( ch & 0x3 ) << 4;
00256 }
00257 
00258 inline void Base64::split2ndOctet(const XMLByte& ch, XMLByte& b2, XMLByte& b3) {
00259     b2 |= ch >> 4;  // combine with previous value
00260     b3 = ( ch & 0xf ) << 2;
00261 }
00262 
00263 inline void Base64::split3rdOctet(const XMLByte& ch, XMLByte& b3, XMLByte& b4) {
00264     b3 |= ch >> 6;  // combine with previous value
00265     b4 = ( ch & 0x3f );
00266 }
00267 
00268 XERCES_CPP_NAMESPACE_END
00269 
00270 #endif