/src/kcodecs/src/kcodecsbase64.cpp

Source
/*  -*- c++ -*-
    SPDX-FileCopyrightText: 2001 Marc Mutz <mutz@kde.org>

    SPDX-License-Identifier: LGPL-2.0-or-later
*/

#include "kcodecsbase64.h"
#include "kcodecs_p.h"

#include <QDebug>

#include <cassert>

using namespace KCodecs;

namespace KCodecs
{
// 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;

//@cond PRIVATE
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', '+', '/'};
//@endcond

class Base64Decoder : public Decoder
{
    uint mStepNo;
    uchar mOutbits;
    bool mSawPadding : 1;

protected:
    friend class Base64Codec;
    Base64Decoder(Codec::NewlineType newline = Codec::NewlineLF)
        : Decoder(newline)
        , mStepNo(0)
        , mOutbits(0)
        , mSawPadding(false)
    {
    }

public:
    ~Base64Decoder() override
    {
    }

    bool decode(const char *&scursor, const char *const send, char *&dcursor, const char *const dend) override;
    // ### really needs no finishing???
    bool finish(char *&dcursor, const char *const dend) override
    {
        Q_UNUSED(dcursor);
        Q_UNUSED(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(Codec::NewlineType newline = Codec::NewlineLF)
        : Encoder(newline)
        , mStepNo(0)
        , mWrittenPacketsOnThisLine(0)
        , mNextbits(0)
        , mInsideFinishing(false)
    {
    }

    bool generic_finish(char *&dcursor, const char *const dend, bool withLFatEnd);

public:
    ~Base64Encoder() override
    {
    }

    bool encode(const char *&scursor, const char *const send, char *&dcursor, const char *const dend) override;

    bool finish(char *&dcursor, const char *const dend) override;

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(Codec::NewlineType newline = Codec::NewlineLF)
        : Base64Encoder(newline)
    {
    }

public:
    bool encode(const char *&scursor, const char *const send, char *&dcursor, const char *const dend) override;
    bool finish(char *&dcursor, const char *const dend) override;
};

Encoder *Base64Codec::makeEncoder(Codec::NewlineType newline) const
{
    return new Base64Encoder(newline);
}

Decoder *Base64Codec::makeDecoder(Codec::NewlineType newline) const
{
    return new Base64Decoder(newline);
}

Encoder *Rfc2047BEncodingCodec::makeEncoder(Codec::NewlineType newline) const
{
    return new Rfc2047BEncodingEncoder(newline);
}

/********************************************************/
/********************************************************/
/********************************************************/

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
                        // qWarning() << "Base64Decoder: unexpected padding"
                        //              "character in input stream";
                    }
                    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) {
            // qWarning() << "Base64Decoder: Embedded padding character"
            //              "encountered!";
            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 (d->outputBufferCursor && !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 (d->outputBufferCursor) {
        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 (d->outputBufferCursor && !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 (d->outputBufferCursor) {
        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 (d->outputBufferCursor && !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);
        Q_FALLTHROUGH();
    // fall through:
    case 2:
        write('=', dcursor, dend);
        Q_FALLTHROUGH();
    // fall through:
    case 0: // completed a quartet - add CRLF
        if (withLFatEnd) {
            writeCRLF(dcursor, dend);
        }
        return flushOutputBuffer(dcursor, dend);
    default:
        assert(0);
    }
    return true; // asserts get compiled out
}

} // namespace KCodecs

Coverage Report

Created: 2026-11-12 07:22

Line	Count	Source
1		/* -- c++ --
2		SPDX-FileCopyrightText: 2001 Marc Mutz <mutz@kde.org>
3
4		SPDX-License-Identifier: LGPL-2.0-or-later
5		*/
6
7		#include "kcodecsbase64.h"
8		#include "kcodecs_p.h"
9
10		#include <QDebug>
11
12		#include <cassert>
13
14		using namespace KCodecs;
15
16		namespace KCodecs
17		{
18		// codec for base64 as specified in RFC 2045
19		// class Base64Codec;
20		// class Base64Decoder;
21		// class Base64Encoder;
22
23		// codec for the B encoding as specified in RFC 2047
24		// class Rfc2047BEncodingCodec;
25		// class Rfc2047BEncodingEncoder;
26		// class Rfc2047BEncodingDecoder;
27
28		//@cond PRIVATE
29		static const uchar base64DecodeMap[128] = {
30		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,
31
32		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,
33
34		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,
35
36		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};
37
38		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',
39		'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r',
40		's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};
41		//@endcond
42
43		class Base64Decoder : public Decoder
44		{
45		uint mStepNo;
46		uchar mOutbits;
47		bool mSawPadding : 1;
48
49		protected:
50		friend class Base64Codec;
51		Base64Decoder(Codec::NewlineType newline = Codec::NewlineLF)
52	146k	: Decoder(newline)
53	146k	, mStepNo(0)
54	146k	, mOutbits(0)
55	146k	, mSawPadding(false)
56	146k	{
57	146k	}
58
59		public:
60		~Base64Decoder() override
61	0	{
62	0	}
63
64		bool decode(const char &scursor, const char const send, char &dcursor, const char const dend) override;
65		// ### really needs no finishing???
66		bool finish(char &dcursor, const char const dend) override
67	1.48k	{
68	1.48k	Q_UNUSED(dcursor);
69	1.48k	Q_UNUSED(dend);
70	1.48k	return true;
71	1.48k	}
72		};
73
74		class Base64Encoder : public Encoder
75		{
76		uint mStepNo;
77		/** number of already written base64-quartets on current line */
78		uint mWrittenPacketsOnThisLine;
79		uchar mNextbits;
80		bool mInsideFinishing : 1;
81
82		protected:
83		friend class Rfc2047BEncodingCodec;
84		friend class Rfc2047BEncodingEncoder;
85		friend class Base64Codec;
86		Base64Encoder(Codec::NewlineType newline = Codec::NewlineLF)
87	125k	: Encoder(newline)
88	125k	, mStepNo(0)
89	125k	, mWrittenPacketsOnThisLine(0)
90	125k	, mNextbits(0)
91	125k	, mInsideFinishing(false)
92	125k	{
93	125k	}
94
95		bool generic_finish(char &dcursor, const char const dend, bool withLFatEnd);
96
97		public:
98		~Base64Encoder() override
99	0	{
100	0	}
101
102		bool encode(const char &scursor, const char const send, char &dcursor, const char const dend) override;
103
104		bool finish(char &dcursor, const char const dend) override;
105
106		protected:
107		bool writeBase64(uchar ch, char &dcursor, const char const dend)
108	529k	{
109	529k	return write(base64EncodeMap[ch], dcursor, dend);
110	529k	}
111		};
112
113		class Rfc2047BEncodingEncoder : public Base64Encoder
114		{
115		protected:
116		friend class Rfc2047BEncodingCodec;
117		Rfc2047BEncodingEncoder(Codec::NewlineType newline = Codec::NewlineLF)
118	0	: Base64Encoder(newline)
119	0	{
120	0	}
121
122		public:
123		bool encode(const char &scursor, const char const send, char &dcursor, const char const dend) override;
124		bool finish(char &dcursor, const char const dend) override;
125		};
126
127		Encoder *Base64Codec::makeEncoder(Codec::NewlineType newline) const
128	125k	{
129	125k	return new Base64Encoder(newline);
130	125k	}
131
132		Decoder *Base64Codec::makeDecoder(Codec::NewlineType newline) const
133	146k	{
134	146k	return new Base64Decoder(newline);
135	146k	}
136
137		Encoder *Rfc2047BEncodingCodec::makeEncoder(Codec::NewlineType newline) const
138	0	{
139	0	return new Rfc2047BEncodingEncoder(newline);
140	0	}
141
142		/********************************************************/
143		/********************************************************/
144		/********************************************************/
145
146		bool Base64Decoder::decode(const char &scursor, const char const send, char &dcursor, const char const dend)
147	147k	{
148	965k	while (dcursor != dend && scursor != send) {
149	868k	uchar ch = *scursor++;
150	868k	uchar value;
151
152		// try converting ch to a 6-bit value:
153	868k	if (ch < 128) {
154	855k	value = base64DecodeMap[ch];
155	855k	} else {
156	12.5k	value = 64;
157	12.5k	}
158
159		// ch isn't of the base64 alphabet, check for other significant chars:
160	868k	if (value >= 64) {
161	207k	if (ch == '=') {
162		// padding:
163	75.0k	if (mStepNo == 0 \|\| mStepNo == 1) {
164	11.3k	if (!mSawPadding) {
165		// malformed
166		// qWarning() << "Base64Decoder: unexpected padding"
167		// "character in input stream";
168	10.5k	}
169	11.3k	mSawPadding = true;
170	11.3k	break;
171	63.7k	} else if (mStepNo == 2) {
172		// ok, there should be another one
173	37.7k	} else if (mStepNo == 3) {
174		// ok, end of encoded stream
175	37.7k	mSawPadding = true;
176	37.7k	break;
177	37.7k	}
178	26.0k	mSawPadding = true;
179	26.0k	mStepNo = (mStepNo + 1) % 4;
180	26.0k	continue;
181	132k	} else {
182		// non-base64 alphabet
183	132k	continue;
184	132k	}
185	207k	}
186
187	660k	if (mSawPadding) {
188		// qWarning() << "Base64Decoder: Embedded padding character"
189		// "encountered!";
190	1.22k	return true;
191	1.22k	}
192
193		// add the new bits to the output stream and flush full octets:
194	659k	switch (mStepNo) {
195	184k	case 0:
196	184k	mOutbits = value << 2;
197	184k	break;
198	180k	case 1:
199	180k	*dcursor++ = (char)(mOutbits \| value >> 4);
200	180k	mOutbits = value << 4;
201	180k	break;
202	154k	case 2:
203	154k	*dcursor++ = (char)(mOutbits \| value >> 2);
204	154k	mOutbits = value << 6;
205	154k	break;
206	140k	case 3:
207	140k	*dcursor++ = (char)(mOutbits \| value);
208	140k	mOutbits = 0;
209	140k	break;
210	0	default:
211	0	assert(0);
212	659k	}
213	659k	mStepNo = (mStepNo + 1) % 4;
214	659k	}
215
216		// return false when caller should call us again:
217	146k	return scursor == send;
218	147k	} // Base64Decoder::decode()
219
220		bool Base64Encoder::encode(const char &scursor, const char const send, char &dcursor, const char const dend)
221	125k	{
222	125k	const uint maxPacketsPerLine = 76 / 4;
223
224		// detect when the caller doesn't adhere to our rules:
225	125k	if (mInsideFinishing) {
226	0	return true;
227	0	}
228
229	507k	while (scursor != send && dcursor != dend) {
230		// properly empty the output buffer before starting something new:
231		// ### fixme: we can optimize this away, since the buffer isn't
232		// written to anyway (most of the time)
233	381k	if (d->outputBufferCursor && !flushOutputBuffer(dcursor, dend)) {
234	0	return scursor == send;
235	0	}
236
237	381k	uchar ch = *scursor++;
238		// mNextbits // (part of) value of next sextet
239
240		// check for line length;
241	381k	if (mStepNo == 0 && mWrittenPacketsOnThisLine >= maxPacketsPerLine) {
242	3.39k	writeCRLF(dcursor, dend);
243	3.39k	mWrittenPacketsOnThisLine = 0;
244	3.39k	}
245
246		// depending on mStepNo, extract value and mNextbits from the
247		// octet stream:
248	381k	switch (mStepNo) {
249	147k	case 0:
250	147k	assert(mNextbits == 0);
251	147k	writeBase64(ch >> 2, dcursor, dend); // top-most 6 bits -> output
252	147k	mNextbits = (ch & 0x3) << 4; // 0..1 bits -> 4..5 in mNextbits
253	147k	break;
254	123k	case 1:
255	123k	assert((mNextbits & ~0x30) == 0);
256	123k	writeBase64(mNextbits \| ch >> 4, dcursor, dend); // 4..7 bits -> 0..3 in value
257	123k	mNextbits = (ch & 0xf) << 2; // 0..3 bits -> 2..5 in mNextbits
258	123k	break;
259	111k	case 2:
260	111k	assert((mNextbits & ~0x3C) == 0);
261	111k	writeBase64(mNextbits \| ch >> 6, dcursor, dend); // 6..7 bits -> 0..1 in value
262	111k	writeBase64(ch & 0x3F, dcursor, dend); // 0..5 bits -> output
263	111k	mNextbits = 0;
264	111k	mWrittenPacketsOnThisLine++;
265	111k	break;
266	0	default:
267	0	assert(0);
268	381k	}
269	381k	mStepNo = (mStepNo + 1) % 3;
270	381k	}
271
272	125k	if (d->outputBufferCursor) {
273	0	flushOutputBuffer(dcursor, dend);
274	0	}
275
276	125k	return scursor == send;
277	125k	}
278
279		bool Rfc2047BEncodingEncoder::encode(const char &scursor, const char const send, char &dcursor, const char const dend)
280	0	{
281		// detect when the caller doesn't adhere to our rules:
282	0	if (mInsideFinishing) {
283	0	return true;
284	0	}
285
286	0	while (scursor != send && dcursor != dend) {
287		// properly empty the output buffer before starting something new:
288		// ### fixme: we can optimize this away, since the buffer isn't
289		// written to anyway (most of the time)
290	0	if (d->outputBufferCursor && !flushOutputBuffer(dcursor, dend)) {
291	0	return scursor == send;
292	0	}
293
294	0	uchar ch = *scursor++;
295		// mNextbits // (part of) value of next sextet
296
297		// depending on mStepNo, extract value and mNextbits from the
298		// octet stream:
299	0	switch (mStepNo) {
300	0	case 0:
301	0	assert(mNextbits == 0);
302	0	writeBase64(ch >> 2, dcursor, dend); // top-most 6 bits -> output
303	0	mNextbits = (ch & 0x3) << 4; // 0..1 bits -> 4..5 in mNextbits
304	0	break;
305	0	case 1:
306	0	assert((mNextbits & ~0x30) == 0);
307	0	writeBase64(mNextbits \| ch >> 4, dcursor, dend); // 4..7 bits -> 0..3 in value
308	0	mNextbits = (ch & 0xf) << 2; // 0..3 bits -> 2..5 in mNextbits
309	0	break;
310	0	case 2:
311	0	assert((mNextbits & ~0x3C) == 0);
312	0	writeBase64(mNextbits \| ch >> 6, dcursor, dend); // 6..7 bits -> 0..1 in value
313	0	writeBase64(ch & 0x3F, dcursor, dend); // 0..5 bits -> output
314	0	mNextbits = 0;
315	0	break;
316	0	default:
317	0	assert(0);
318	0	}
319	0	mStepNo = (mStepNo + 1) % 3;
320	0	}
321
322	0	if (d->outputBufferCursor) {
323	0	flushOutputBuffer(dcursor, dend);
324	0	}
325
326	0	return scursor == send;
327	0	}
328
329		bool Base64Encoder::finish(char &dcursor, const char const dend)
330	125k	{
331	125k	return generic_finish(dcursor, dend, true);
332	125k	}
333
334		bool Rfc2047BEncodingEncoder::finish(char &dcursor, const char const dend)
335	0	{
336	0	return generic_finish(dcursor, dend, false);
337	0	}
338
339		bool Base64Encoder::generic_finish(char &dcursor, const char const dend, bool withLFatEnd)
340	125k	{
341	125k	if (mInsideFinishing) {
342	0	return flushOutputBuffer(dcursor, dend);
343	0	}
344
345	125k	if (d->outputBufferCursor && !flushOutputBuffer(dcursor, dend)) {
346	0	return false;
347	0	}
348
349	125k	mInsideFinishing = true;
350
351		//
352		// writing out the last mNextbits...
353		//
354	125k	switch (mStepNo) {
355	23.2k	case 1: // 2 mNextbits waiting to be written. Needs two padding chars:
356	35.8k	case 2: // 4 or 6 mNextbits waiting to be written. Completes a block
357	35.8k	writeBase64(mNextbits, dcursor, dend);
358	35.8k	mNextbits = 0;
359	35.8k	break;
360	89.2k	case 0: // no padding, nothing to be written, except possibly the CRLF
361	89.2k	assert(mNextbits == 0);
362	89.2k	break;
363	89.2k	default:
364	0	assert(0);
365	125k	}
366
367		//
368		// adding padding...
369		//
370	125k	switch (mStepNo) {
371	23.2k	case 1:
372	23.2k	write('=', dcursor, dend);
373	23.2k	Q_FALLTHROUGH();
374		// fall through:
375	35.8k	case 2:
376	35.8k	write('=', dcursor, dend);
377	35.8k	Q_FALLTHROUGH();
378		// fall through:
379	125k	case 0: // completed a quartet - add CRLF
380	125k	if (withLFatEnd) {
381	125k	writeCRLF(dcursor, dend);
382	125k	}
383	125k	return flushOutputBuffer(dcursor, dend);
384	0	default:
385	0	assert(0);
386	125k	}
387	0	return true; // asserts get compiled out
388	125k	}
389
390		} // namespace KCodecs