You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
406 lines
12 KiB
406 lines
12 KiB
/*
|
|
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 TQt library by Trolltech AS, Norway (or with modified versions
|
|
of TQt that use the same license as TQt), 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
|
|
TQt. 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
|