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+/* -*- c++ -*-
+ kmime_codec_base64.cpp
+
+ This file is part of KMime, the KDE internet mail/usenet news message library.
+ Copyright (c) 2001 Marc Mutz <mutz@kde.org>
+
+ KMime is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License, version 2, as
+ published by the Free Software Foundation.
+
+ KMime is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+ In addition, as a special exception, the copyright holders give
+ permission to link the code of this library with any edition of
+ the Qt library by Trolltech AS, Norway (or with modified versions
+ of Qt that use the same license as Qt), and distribute linked
+ combinations including the two. You must obey the GNU General
+ Public License in all respects for all of the code used other than
+ Qt. If you modify this file, you may extend this exception to
+ your version of the file, but you are not obligated to do so. If
+ you do not wish to do so, delete this exception statement from
+ your version.
+*/
+
+#include "kmime_codec_base64.h"
+
+#include <kdebug.h>
+
+#include <cassert>
+
+using namespace KMime;
+
+namespace KMime {
+
+// codec for base64 as specified in RFC 2045
+ //class Base64Codec;
+ //class Base64Decoder;
+ //class Base64Encoder;
+
+// codec for the B encoding as specified in RFC 2047
+ //class Rfc2047BEncodingCodec;
+ //class Rfc2047BEncodingEncoder;
+ //class Rfc2047BEncodingDecoder;
+
+
+static const uchar base64DecodeMap[128] = {
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
+ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
+
+ 64, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
+
+ 64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+ 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64
+};
+
+static const char base64EncodeMap[64] = {
+ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+ 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+ 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+ 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
+ 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+ 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
+ 'w', 'x', 'y', 'z', '0', '1', '2', '3',
+ '4', '5', '6', '7', '8', '9', '+', '/'
+};
+
+
+class Base64Decoder : public Decoder {
+ uint mStepNo;
+ uchar mOutbits;
+ bool mSawPadding : 1;
+
+protected:
+ friend class Base64Codec;
+ Base64Decoder( bool withCRLF=false )
+ : Decoder( withCRLF ), mStepNo(0), mOutbits(0),
+ mSawPadding(false) {}
+
+public:
+ virtual ~Base64Decoder() {}
+
+ bool decode( const char* & scursor, const char * const send,
+ char* & dcursor, const char * const dend );
+ // ### really needs no finishing???
+ bool finish( char* & /*dcursor*/, const char * const /*dend*/ ) { return true; }
+};
+
+
+
+class Base64Encoder : public Encoder {
+ uint mStepNo;
+ /** number of already written base64-quartets on current line */
+ uint mWrittenPacketsOnThisLine;
+ uchar mNextbits;
+ bool mInsideFinishing : 1;
+
+protected:
+ friend class Rfc2047BEncodingCodec;
+ friend class Rfc2047BEncodingEncoder;
+ friend class Base64Codec;
+ Base64Encoder( bool withCRLF=false )
+ : Encoder( withCRLF ), mStepNo(0), mWrittenPacketsOnThisLine(0),
+ mNextbits(0), mInsideFinishing(false) {}
+
+ bool generic_finish( char* & dcursor, const char * const dend,
+ bool withLFatEnd );
+
+public:
+ virtual ~Base64Encoder() {}
+
+ bool encode( const char* & scursor, const char * const send,
+ char* & dcursor, const char * const dend );
+
+ bool finish( char* & dcursor, const char * const dend );
+
+protected:
+ bool writeBase64( uchar ch, char* & dcursor, const char * const dend ) {
+ return write( base64EncodeMap[ ch ], dcursor, dend );
+ }
+};
+
+
+
+class Rfc2047BEncodingEncoder : public Base64Encoder {
+protected:
+ friend class Rfc2047BEncodingCodec;
+ Rfc2047BEncodingEncoder( bool withCRLF=false )
+ : Base64Encoder( withCRLF ) {};
+public:
+ bool encode( const char* & scursor, const char * const send,
+ char* & dcursor, const char * const dend );
+ bool finish( char* & dcursor, const char * const dend );
+};
+
+
+Encoder * Base64Codec::makeEncoder( bool withCRLF ) const {
+ return new Base64Encoder( withCRLF );
+}
+
+Decoder * Base64Codec::makeDecoder( bool withCRLF ) const {
+ return new Base64Decoder( withCRLF );
+}
+
+Encoder * Rfc2047BEncodingCodec::makeEncoder( bool withCRLF ) const {
+ return new Rfc2047BEncodingEncoder( withCRLF );
+}
+
+ /********************************************************/
+ /********************************************************/
+ /********************************************************/
+
+
+bool Base64Decoder::decode( const char* & scursor, const char * const send,
+ char* & dcursor, const char * const dend )
+{
+ while ( dcursor != dend && scursor != send ) {
+ uchar ch = *scursor++;
+ uchar value;
+
+ // try converting ch to a 6-bit value:
+ if ( ch < 128 )
+ value = base64DecodeMap[ ch ];
+ else
+ value = 64;
+
+ // ch isn't of the base64 alphabet, check for other significant chars:
+ if ( value >= 64 ) {
+ if ( ch == '=' ) {
+ // padding:
+ if ( mStepNo == 0 || mStepNo == 1) {
+ if (!mSawPadding) {
+ // malformed
+ kdWarning() << "Base64Decoder: unexpected padding "
+ "character in input stream" << endl;
+ }
+ mSawPadding = true;
+ break;
+ } else if ( mStepNo == 2 ) {
+ // ok, there should be another one
+ } else if ( mStepNo == 3 ) {
+ // ok, end of encoded stream
+ mSawPadding = true;
+ break;
+ }
+ mSawPadding = true;
+ mStepNo = (mStepNo + 1) % 4;
+ continue;
+ } else {
+ // non-base64 alphabet
+ continue;
+ }
+ }
+
+ if ( mSawPadding ) {
+ kdWarning() << "Base64Decoder: Embedded padding character "
+ "encountered!" << endl;
+ return true;
+ }
+
+ // add the new bits to the output stream and flush full octets:
+ switch ( mStepNo ) {
+ case 0:
+ mOutbits = value << 2;
+ break;
+ case 1:
+ *dcursor++ = (char)(mOutbits | value >> 4);
+ mOutbits = value << 4;
+ break;
+ case 2:
+ *dcursor++ = (char)(mOutbits | value >> 2);
+ mOutbits = value << 6;
+ break;
+ case 3:
+ *dcursor++ = (char)(mOutbits | value);
+ mOutbits = 0;
+ break;
+ default:
+ assert( 0 );
+ }
+ mStepNo = (mStepNo + 1) % 4;
+ }
+
+ // return false when caller should call us again:
+ return (scursor == send);
+} // Base64Decoder::decode()
+
+
+
+bool Base64Encoder::encode( const char* & scursor, const char * const send,
+ char* & dcursor, const char * const dend ) {
+ const uint maxPacketsPerLine = 76 / 4;
+
+ // detect when the caller doesn't adhere to our rules:
+ if ( mInsideFinishing ) return true;
+
+ while ( scursor != send && dcursor != dend ) {
+ // properly empty the output buffer before starting something new:
+ // ### fixme: we can optimize this away, since the buffer isn't
+ // written to anyway (most of the time)
+ if ( mOutputBufferCursor && !flushOutputBuffer( dcursor, dend ) )
+ return (scursor == send);
+
+ uchar ch = *scursor++;
+ // mNextbits // (part of) value of next sextet
+
+ // check for line length;
+ if ( mStepNo == 0 && mWrittenPacketsOnThisLine >= maxPacketsPerLine ) {
+ writeCRLF( dcursor, dend );
+ mWrittenPacketsOnThisLine = 0;
+ }
+
+ // depending on mStepNo, extract value and mNextbits from the
+ // octet stream:
+ switch ( mStepNo ) {
+ case 0:
+ assert( mNextbits == 0 );
+ writeBase64( ch >> 2, dcursor, dend ); // top-most 6 bits -> output
+ mNextbits = (ch & 0x3) << 4; // 0..1 bits -> 4..5 in mNextbits
+ break;
+ case 1:
+ assert( (mNextbits & ~0x30) == 0 );
+ writeBase64( mNextbits | ch >> 4, dcursor, dend ); // 4..7 bits -> 0..3 in value
+ mNextbits = (ch & 0xf) << 2; // 0..3 bits -> 2..5 in mNextbits
+ break;
+ case 2:
+ assert( (mNextbits & ~0x3C) == 0 );
+ writeBase64( mNextbits | ch >> 6, dcursor, dend ); // 6..7 bits -> 0..1 in value
+ writeBase64( ch & 0x3F, dcursor, dend ); // 0..5 bits -> output
+ mNextbits = 0;
+ mWrittenPacketsOnThisLine++;
+ break;
+ default:
+ assert( 0 );
+ }
+ mStepNo = ( mStepNo + 1 ) % 3;
+ }
+
+ if ( mOutputBufferCursor ) flushOutputBuffer( dcursor, dend );
+
+ return (scursor == send);
+}
+
+
+bool Rfc2047BEncodingEncoder::encode( const char* & scursor,
+ const char * const send,
+ char* & dcursor,
+ const char * const dend )
+{
+ // detect when the caller doesn't adhere to our rules:
+ if ( mInsideFinishing ) return true;
+
+ while ( scursor != send && dcursor != dend ) {
+ // properly empty the output buffer before starting something new:
+ // ### fixme: we can optimize this away, since the buffer isn't
+ // written to anyway (most of the time)
+ if ( mOutputBufferCursor && !flushOutputBuffer( dcursor, dend ) )
+ return (scursor == send);
+
+ uchar ch = *scursor++;
+ // mNextbits // (part of) value of next sextet
+
+ // depending on mStepNo, extract value and mNextbits from the
+ // octet stream:
+ switch ( mStepNo ) {
+ case 0:
+ assert( mNextbits == 0 );
+ writeBase64( ch >> 2, dcursor, dend ); // top-most 6 bits -> output
+ mNextbits = (ch & 0x3) << 4; // 0..1 bits -> 4..5 in mNextbits
+ break;
+ case 1:
+ assert( (mNextbits & ~0x30) == 0 );
+ writeBase64( mNextbits | ch >> 4, dcursor, dend ); // 4..7 bits -> 0..3 in value
+ mNextbits = (ch & 0xf) << 2; // 0..3 bits -> 2..5 in mNextbits
+ break;
+ case 2:
+ assert( (mNextbits & ~0x3C) == 0 );
+ writeBase64( mNextbits | ch >> 6, dcursor, dend ); // 6..7 bits -> 0..1 in value
+ writeBase64( ch & 0x3F, dcursor, dend ); // 0..5 bits -> output
+ mNextbits = 0;
+ break;
+ default:
+ assert( 0 );
+ }
+ mStepNo = ( mStepNo + 1 ) % 3;
+ }
+
+ if ( mOutputBufferCursor ) flushOutputBuffer( dcursor, dend );
+
+ return (scursor == send);
+}
+
+
+bool Base64Encoder::finish( char* & dcursor, const char * const dend ) {
+ return generic_finish( dcursor, dend, true );
+}
+
+bool Rfc2047BEncodingEncoder::finish( char* & dcursor,
+ const char * const dend ) {
+ return generic_finish( dcursor, dend, false );
+}
+
+bool Base64Encoder::generic_finish( char* & dcursor, const char * const dend,
+ bool withLFatEnd )
+{
+ if ( mInsideFinishing )
+ return flushOutputBuffer( dcursor, dend );
+
+ if ( mOutputBufferCursor && !flushOutputBuffer( dcursor, dend ) )
+ return false;
+
+ mInsideFinishing = true;
+
+ //
+ // writing out the last mNextbits...
+ //
+ switch ( mStepNo ) {
+ case 1: // 2 mNextbits waiting to be written. Needs two padding chars:
+ case 2: // 4 or 6 mNextbits waiting to be written. Completes a block
+ writeBase64( mNextbits, dcursor, dend );
+ mNextbits = 0;
+ break;
+ case 0: // no padding, nothing to be written, except possibly the CRLF
+ assert( mNextbits == 0 );
+ break;
+ default:
+ assert( 0 );
+ }
+
+ //
+ // adding padding...
+ //
+ switch( mStepNo ) {
+ case 1:
+ write( '=', dcursor, dend );
+ // fall through:
+ case 2:
+ write( '=', dcursor, dend );
+ // fall through:
+ case 0: // completed an quartet - add CRLF
+ if ( withLFatEnd )
+ writeCRLF( dcursor, dend );
+ return flushOutputBuffer( dcursor, dend );
+ default:
+ assert( 0 );
+ }
+return true; // asserts get compiled out
+}
+
+
+
+
+
+
+} // namespace KMime
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