/src/libzip/lib/zip_algorithm_xz.c

Source
/*
  zip_algorithm_xz.c -- LZMA/XZ (de)compression routines
  Bazed on zip_algorithm_deflate.c -- deflate (de)compression routines
  Copyright (C) 2017-2025 Dieter Baron and Thomas Klausner

  This file is part of libzip, a library to manipulate ZIP archives.
  The authors can be contacted at <info@libzip.org>

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.
  3. The names of the authors may not be used to endorse or promote
     products derived from this software without specific prior
     written permission.

  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include "zipint.h"

#include <limits.h>
#include <lzma.h>
#include <stdlib.h>
#include <zlib.h>

enum header_state {
    INCOMPLETE,
    OUTPUT,
    DONE
};

#define HEADER_BYTES_ZIP 9
#define HEADER_MAGIC_LENGTH 4
#define HEADER_MAGIC1_OFFSET 0
#define HEADER_MAGIC2_OFFSET 2
#define HEADER_SIZE_OFFSET 9
#define HEADER_SIZE_LENGTH 8
#define HEADER_PARAMETERS_LENGTH 5
#define HEADER_LZMA_ALONE_LENGTH (HEADER_PARAMETERS_LENGTH + HEADER_SIZE_LENGTH)

struct ctx {
    zip_error_t *error;
    bool compress;
    zip_uint32_t compression_flags;
    bool end_of_input;
    lzma_stream zstr;
    zip_uint16_t method;
    /* header member is used for converting from zip to "lzma alone"
     * format
     *
     * "lzma alone" file format starts with:
     * 5 bytes lzma parameters
     * 8 bytes uncompressed size
     * compressed data
     *
     * zip archive on-disk format starts with
     * 4 bytes magic (first two bytes vary, e.g. 0x0914 or 0x1002, next bytes are 0x0500)
     * 5 bytes lzma parameters
     * compressed data
     *
     * we read the data into a header of the form
     * 4 bytes magic
     * 5 bytes lzma parameters
     * 8 bytes uncompressed size
     */
    zip_uint8_t header[HEADER_MAGIC_LENGTH + HEADER_LZMA_ALONE_LENGTH];
    zip_uint8_t header_bytes_offset;
    enum header_state header_state;
    zip_uint64_t uncompresssed_size;
};


static zip_uint64_t maximum_compressed_size(zip_uint64_t uncompressed_size) {
    /*
     According to https://sourceforge.net/p/sevenzip/discussion/45797/thread/b6bd62f8/

     1) you can use
     outSize = 1.10 * originalSize + 64 KB.
     in most cases outSize is less then 1.02 from originalSize.
     2) You can try LZMA2, where
     outSize can be = 1.001 * originalSize + 1 KB.
     */
    /* 13 bytes added for lzma alone header */
    zip_uint64_t compressed_size = (zip_uint64_t)((double)uncompressed_size * 1.1) + 64 * 1024 + 13;

    if (compressed_size < uncompressed_size) {
        return ZIP_UINT64_MAX;
    }
    return compressed_size;
}


static void *allocate(bool compress, zip_uint32_t compression_flags, zip_error_t *error, zip_uint16_t method) {
    struct ctx *ctx;

    if ((ctx = (struct ctx *)malloc(sizeof(*ctx))) == NULL) {
        zip_error_set(error, ZIP_ER_MEMORY, 0);
        return NULL;
    }

    ctx->error = error;
    ctx->compress = compress;
    if (compression_flags <= 9) {
        ctx->compression_flags = compression_flags;
    }
    else {
        ctx->compression_flags = 6; /* default value */
    }
    ctx->compression_flags |= LZMA_PRESET_EXTREME;
    ctx->end_of_input = false;
    memset(ctx->header, 0, sizeof(ctx->header));
    ctx->header_bytes_offset = 0;
    if (method == ZIP_CM_LZMA) {
        ctx->header_state = INCOMPLETE;
    }
    else {
        ctx->header_state = DONE;
    }
    memset(&ctx->zstr, 0, sizeof(ctx->zstr));
    ctx->method = method;
    return ctx;
}


static void *compress_allocate(zip_uint16_t method, zip_uint32_t compression_flags, zip_error_t *error) {
    return allocate(true, compression_flags, error, method);
}


static void *decompress_allocate(zip_uint16_t method, zip_uint32_t compression_flags, zip_error_t *error) {
    return allocate(false, compression_flags, error, method);
}


static void deallocate(void *ud) {
    struct ctx *ctx = (struct ctx *)ud;
    free(ctx);
}


static zip_uint16_t general_purpose_bit_flags(void *ud) {
    struct ctx *ctx = (struct ctx *)ud;

    if (!ctx->compress) {
        return 0;
    }

    if (ctx->method == ZIP_CM_LZMA) {
        /* liblzma always returns an EOS/EOPM marker, see
         * https://sourceforge.net/p/lzmautils/discussion/708858/thread/84c5dbb9/#a5e4/3764 */
        return 1 << 1;
    }
    return 0;
}

static int map_error(lzma_ret ret) {
    switch (ret) {
    case LZMA_DATA_ERROR:
    case LZMA_UNSUPPORTED_CHECK:
        return ZIP_ER_COMPRESSED_DATA;

    case LZMA_MEM_ERROR:
        return ZIP_ER_MEMORY;

    case LZMA_OPTIONS_ERROR:
        return ZIP_ER_INVAL;

    default:
        return ZIP_ER_INTERNAL;
    }
}


static bool start(void *ud, zip_stat_t *st, zip_file_attributes_t *attributes) {
    struct ctx *ctx = (struct ctx *)ud;
    lzma_ret ret;

    lzma_options_lzma opt_lzma;
    lzma_lzma_preset(&opt_lzma, ctx->compression_flags);
    lzma_filter filters[] = {
        {.id = (ctx->method == ZIP_CM_LZMA ? LZMA_FILTER_LZMA1 : LZMA_FILTER_LZMA2), .options = &opt_lzma},
        {.id = LZMA_VLI_UNKNOWN, .options = NULL},
    };

    ctx->zstr.avail_in = 0;
    ctx->zstr.next_in = NULL;
    ctx->zstr.avail_out = 0;
    ctx->zstr.next_out = NULL;

    if (ctx->compress) {
        if (ctx->method == ZIP_CM_LZMA) {
            ret = lzma_alone_encoder(&ctx->zstr, filters[0].options);
        }
        else {
            ret = lzma_stream_encoder(&ctx->zstr, filters, LZMA_CHECK_CRC64);
        }
    }
    else {
        if (ctx->method == ZIP_CM_LZMA) {
            ret = lzma_alone_decoder(&ctx->zstr, UINT64_MAX);
        }
        else {
            ret = lzma_stream_decoder(&ctx->zstr, UINT64_MAX, LZMA_CONCATENATED);
        }
    }

    if (ret != LZMA_OK) {
        zip_error_set(ctx->error, map_error(ret), 0);
        return false;
    }

    /* If general purpose bits 1 & 2 are both zero, write real uncompressed size in header. */
    if ((attributes->valid & ZIP_FILE_ATTRIBUTES_GENERAL_PURPOSE_BIT_FLAGS) && (attributes->general_purpose_bit_mask & 0x6) == 0x6 && (attributes->general_purpose_bit_flags & 0x06) == 0 && (st->valid & ZIP_STAT_SIZE)) {
        ctx->uncompresssed_size = st->size;
    }
    else {
        ctx->uncompresssed_size = ZIP_UINT64_MAX;
    }

    return true;
}


static bool end(void *ud) {
    struct ctx *ctx = (struct ctx *)ud;

    lzma_end(&ctx->zstr);
    return true;
}


static bool input(void *ud, zip_uint8_t *data, zip_uint64_t length) {
    struct ctx *ctx = (struct ctx *)ud;

    if (length > UINT_MAX || ctx->zstr.avail_in > 0) {
        zip_error_set(ctx->error, ZIP_ER_INVAL, 0);
        return false;
    }

    /* For decompression of LZMA1: Have we read the full "lzma alone" header yet? */
    if (ctx->method == ZIP_CM_LZMA && !ctx->compress && ctx->header_state == INCOMPLETE) {
        /* if not, get more of the data */
        zip_uint8_t got = (zip_uint8_t)ZIP_MIN(HEADER_BYTES_ZIP - ctx->header_bytes_offset, length);
        (void)memcpy_s(ctx->header + ctx->header_bytes_offset, sizeof(ctx->header) - ctx->header_bytes_offset, data, got);
        ctx->header_bytes_offset += got;
        length -= got;
        data += got;
        /* Do we have a complete header now? */
        if (ctx->header_bytes_offset == HEADER_BYTES_ZIP) {
            Bytef empty_buffer[1];
            zip_buffer_t *buffer;
            /* check magic */
            if (ctx->header[HEADER_MAGIC2_OFFSET] != 0x05 || ctx->header[HEADER_MAGIC2_OFFSET + 1] != 0x00) {
                /* magic does not match */
                zip_error_set(ctx->error, ZIP_ER_COMPRESSED_DATA, 0);
                return false;
            }
            /* set size of uncompressed data in "lzma alone" header to "unknown" */
            if ((buffer = _zip_buffer_new(ctx->header + HEADER_SIZE_OFFSET, HEADER_SIZE_LENGTH)) == NULL) {
                zip_error_set(ctx->error, ZIP_ER_MEMORY, 0);
                return false;
            }
            _zip_buffer_put_64(buffer, ctx->uncompresssed_size);
            _zip_buffer_free(buffer);
            /* Feed header into "lzma alone" decoder, for
             * initialization; this should not produce output. */
            ctx->zstr.next_in = (void *)(ctx->header + HEADER_MAGIC_LENGTH);
            ctx->zstr.avail_in = HEADER_LZMA_ALONE_LENGTH;
            ctx->zstr.total_in = 0;
            ctx->zstr.next_out = empty_buffer;
            ctx->zstr.avail_out = sizeof(*empty_buffer);
            ctx->zstr.total_out = 0;
            /* this just initializes the decoder and does not produce output, so it consumes the complete header */
            if (lzma_code(&ctx->zstr, LZMA_RUN) != LZMA_OK || ctx->zstr.total_out > 0) {
                zip_error_set(ctx->error, ZIP_ER_COMPRESSED_DATA, 0);
                return false;
            }
            ctx->header_state = DONE;
        }
    }
    ctx->zstr.avail_in = (uInt)length;
    ctx->zstr.next_in = (Bytef *)data;

    return true;
}


static bool end_of_input(void *ud) {
    struct ctx *ctx = (struct ctx *)ud;

    ctx->end_of_input = true;
    return ctx->zstr.avail_in != 0;
}


static zip_compression_status_t process(void *ud, zip_uint8_t *data, zip_uint64_t *length) {
    struct ctx *ctx = (struct ctx *)ud;
    uInt avail_out;
    lzma_ret ret;
    /* for compression of LZMA1 */
    if (ctx->method == ZIP_CM_LZMA && ctx->compress) {
        if (ctx->header_state == INCOMPLETE) {
            /* write magic to output buffer */
            ctx->header[0] = 0x09;
            ctx->header[1] = 0x14;
            ctx->header[2] = 0x05;
            ctx->header[3] = 0x00;
            /* generate lzma parameters into output buffer */
            ctx->zstr.avail_out = HEADER_LZMA_ALONE_LENGTH;
            ctx->zstr.next_out = ctx->header + HEADER_MAGIC_LENGTH;
            ret = lzma_code(&ctx->zstr, LZMA_RUN);
            if (ret != LZMA_OK || ctx->zstr.avail_out != 0) {
                /* assume that the whole header will be provided with the first call to lzma_code */
                return ZIP_COMPRESSION_ERROR;
            }
            ctx->header_state = OUTPUT;
        }
        if (ctx->header_state == OUTPUT) {
            /* write header */
            zip_uint8_t write_len = (zip_uint8_t)ZIP_MIN(HEADER_BYTES_ZIP - ctx->header_bytes_offset, *length);
            (void)memcpy_s(data, *length, ctx->header + ctx->header_bytes_offset, write_len);
            ctx->header_bytes_offset += write_len;
            *length = write_len;
            if (ctx->header_bytes_offset == HEADER_BYTES_ZIP) {
                ctx->header_state = DONE;
            }
            return ZIP_COMPRESSION_OK;
        }
    }

    avail_out = (uInt)ZIP_MIN(UINT_MAX, *length);
    ctx->zstr.avail_out = avail_out;
    ctx->zstr.next_out = (Bytef *)data;

    ret = lzma_code(&ctx->zstr, ctx->end_of_input ? LZMA_FINISH : LZMA_RUN);
    *length = avail_out - ctx->zstr.avail_out;

    switch (ret) {
    case LZMA_OK:
        return ZIP_COMPRESSION_OK;

    case LZMA_STREAM_END:
        return ZIP_COMPRESSION_END;

    case LZMA_BUF_ERROR:
        if (ctx->zstr.avail_in == 0) {
            return ZIP_COMPRESSION_NEED_DATA;
        }

        /* fallthrough */
    default:
        zip_error_set(ctx->error, map_error(ret), 0);
        return ZIP_COMPRESSION_ERROR;
    }
}

/* Version Required should be set to 63 (6.3) because this compression
   method was only defined in appnote.txt version 6.3.8, but Winzip
   does not unpack it if the value is not 20. */

/* clang-format off */

zip_compression_algorithm_t zip_algorithm_xz_compress = {
    maximum_compressed_size,
    compress_allocate,
    deallocate,
    general_purpose_bit_flags,
    20,
    start,
    end,
    input,
    end_of_input,
    process
};


zip_compression_algorithm_t zip_algorithm_xz_decompress = {
    maximum_compressed_size,
    decompress_allocate,
    deallocate,
    general_purpose_bit_flags,
    20,
    start,
    end,
    input,
    end_of_input,
    process
};

/* clang-format on */

Coverage Report

Created: 2026-04-01 07:49

Line	Count	Source
1		/*
2		zip_algorithm_xz.c -- LZMA/XZ (de)compression routines
3		Bazed on zip_algorithm_deflate.c -- deflate (de)compression routines
4		Copyright (C) 2017-2025 Dieter Baron and Thomas Klausner
5
6		This file is part of libzip, a library to manipulate ZIP archives.
7		The authors can be contacted at <info@libzip.org>
8
9		Redistribution and use in source and binary forms, with or without
10		modification, are permitted provided that the following conditions
11		are met:
12		1. Redistributions of source code must retain the above copyright
13		notice, this list of conditions and the following disclaimer.
14		2. Redistributions in binary form must reproduce the above copyright
15		notice, this list of conditions and the following disclaimer in
16		the documentation and/or other materials provided with the
17		distribution.
18		3. The names of the authors may not be used to endorse or promote
19		products derived from this software without specific prior
20		written permission.
21
22		THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
23		OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
24		WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25		ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
26		DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27		DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
28		GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29		INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
30		IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
31		OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
32		IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33		*/
34
35		#include "zipint.h"
36
37		#include <limits.h>
38		#include <lzma.h>
39		#include <stdlib.h>
40		#include <zlib.h>
41
42		enum header_state {
43		INCOMPLETE,
44		OUTPUT,
45		DONE
46		};
47
48	0	#define HEADER_BYTES_ZIP 9
49	0	#define HEADER_MAGIC_LENGTH 4
50		#define HEADER_MAGIC1_OFFSET 0
51	0	#define HEADER_MAGIC2_OFFSET 2
52	0	#define HEADER_SIZE_OFFSET 9
53	0	#define HEADER_SIZE_LENGTH 8
54	0	#define HEADER_PARAMETERS_LENGTH 5
55	0	#define HEADER_LZMA_ALONE_LENGTH (HEADER_PARAMETERS_LENGTH + HEADER_SIZE_LENGTH)
56
57		struct ctx {
58		zip_error_t *error;
59		bool compress;
60		zip_uint32_t compression_flags;
61		bool end_of_input;
62		lzma_stream zstr;
63		zip_uint16_t method;
64		/* header member is used for converting from zip to "lzma alone"
65		* format
66		*
67		* "lzma alone" file format starts with:
68		* 5 bytes lzma parameters
69		* 8 bytes uncompressed size
70		* compressed data
71		*
72		* zip archive on-disk format starts with
73		* 4 bytes magic (first two bytes vary, e.g. 0x0914 or 0x1002, next bytes are 0x0500)
74		* 5 bytes lzma parameters
75		* compressed data
76		*
77		* we read the data into a header of the form
78		* 4 bytes magic
79		* 5 bytes lzma parameters
80		* 8 bytes uncompressed size
81		*/
82		zip_uint8_t header[HEADER_MAGIC_LENGTH + HEADER_LZMA_ALONE_LENGTH];
83		zip_uint8_t header_bytes_offset;
84		enum header_state header_state;
85		zip_uint64_t uncompresssed_size;
86		};
87
88
89	0	static zip_uint64_t maximum_compressed_size(zip_uint64_t uncompressed_size) {
90		/*
91		According to https://sourceforge.net/p/sevenzip/discussion/45797/thread/b6bd62f8/
92
93		1) you can use
94		outSize = 1.10 * originalSize + 64 KB.
95		in most cases outSize is less then 1.02 from originalSize.
96		2) You can try LZMA2, where
97		outSize can be = 1.001 * originalSize + 1 KB.
98		*/
99		/* 13 bytes added for lzma alone header */
100	0	zip_uint64_t compressed_size = (zip_uint64_t)((double)uncompressed_size * 1.1) + 64 * 1024 + 13;
101
102	0	if (compressed_size < uncompressed_size) {
103	0	return ZIP_UINT64_MAX;
104	0	}
105	0	return compressed_size;
106	0	}
107
108
109	0	static void allocate(bool compress, zip_uint32_t compression_flags, zip_error_t error, zip_uint16_t method) {
110	0	struct ctx *ctx;
111
112	0	if ((ctx = (struct ctx )malloc(sizeof(ctx))) == NULL) {
113	0	zip_error_set(error, ZIP_ER_MEMORY, 0);
114	0	return NULL;
115	0	}
116
117	0	ctx->error = error;
118	0	ctx->compress = compress;
119	0	if (compression_flags <= 9) {
120	0	ctx->compression_flags = compression_flags;
121	0	}
122	0	else {
123	0	ctx->compression_flags = 6; /* default value */
124	0	}
125	0	ctx->compression_flags \|= LZMA_PRESET_EXTREME;
126	0	ctx->end_of_input = false;
127	0	memset(ctx->header, 0, sizeof(ctx->header));
128	0	ctx->header_bytes_offset = 0;
129	0	if (method == ZIP_CM_LZMA) {
130	0	ctx->header_state = INCOMPLETE;
131	0	}
132	0	else {
133	0	ctx->header_state = DONE;
134	0	}
135	0	memset(&ctx->zstr, 0, sizeof(ctx->zstr));
136	0	ctx->method = method;
137	0	return ctx;
138	0	}
139
140
141	0	static void compress_allocate(zip_uint16_t method, zip_uint32_t compression_flags, zip_error_t error) {
142	0	return allocate(true, compression_flags, error, method);
143	0	}
144
145
146	0	static void decompress_allocate(zip_uint16_t method, zip_uint32_t compression_flags, zip_error_t error) {
147	0	return allocate(false, compression_flags, error, method);
148	0	}
149
150
151	0	static void deallocate(void *ud) {
152	0	struct ctx ctx = (struct ctx )ud;
153	0	free(ctx);
154	0	}
155
156
157	0	static zip_uint16_t general_purpose_bit_flags(void *ud) {
158	0	struct ctx ctx = (struct ctx )ud;
159
160	0	if (!ctx->compress) {
161	0	return 0;
162	0	}
163
164	0	if (ctx->method == ZIP_CM_LZMA) {
165		/* liblzma always returns an EOS/EOPM marker, see
166		* https://sourceforge.net/p/lzmautils/discussion/708858/thread/84c5dbb9/#a5e4/3764 */
167	0	return 1 << 1;
168	0	}
169	0	return 0;
170	0	}
171
172	0	static int map_error(lzma_ret ret) {
173	0	switch (ret) {
174	0	case LZMA_DATA_ERROR:
175	0	case LZMA_UNSUPPORTED_CHECK:
176	0	return ZIP_ER_COMPRESSED_DATA;
177
178	0	case LZMA_MEM_ERROR:
179	0	return ZIP_ER_MEMORY;
180
181	0	case LZMA_OPTIONS_ERROR:
182	0	return ZIP_ER_INVAL;
183
184	0	default:
185	0	return ZIP_ER_INTERNAL;
186	0	}
187	0	}
188
189
190	0	static bool start(void ud, zip_stat_t st, zip_file_attributes_t *attributes) {
191	0	struct ctx ctx = (struct ctx )ud;
192	0	lzma_ret ret;
193
194	0	lzma_options_lzma opt_lzma;
195	0	lzma_lzma_preset(&opt_lzma, ctx->compression_flags);
196	0	lzma_filter filters[] = {
197	0	{.id = (ctx->method == ZIP_CM_LZMA ? LZMA_FILTER_LZMA1 : LZMA_FILTER_LZMA2), .options = &opt_lzma},
198	0	{.id = LZMA_VLI_UNKNOWN, .options = NULL},
199	0	};
200
201	0	ctx->zstr.avail_in = 0;
202	0	ctx->zstr.next_in = NULL;
203	0	ctx->zstr.avail_out = 0;
204	0	ctx->zstr.next_out = NULL;
205
206	0	if (ctx->compress) {
207	0	if (ctx->method == ZIP_CM_LZMA) {
208	0	ret = lzma_alone_encoder(&ctx->zstr, filters[0].options);
209	0	}
210	0	else {
211	0	ret = lzma_stream_encoder(&ctx->zstr, filters, LZMA_CHECK_CRC64);
212	0	}
213	0	}
214	0	else {
215	0	if (ctx->method == ZIP_CM_LZMA) {
216	0	ret = lzma_alone_decoder(&ctx->zstr, UINT64_MAX);
217	0	}
218	0	else {
219	0	ret = lzma_stream_decoder(&ctx->zstr, UINT64_MAX, LZMA_CONCATENATED);
220	0	}
221	0	}
222
223	0	if (ret != LZMA_OK) {
224	0	zip_error_set(ctx->error, map_error(ret), 0);
225	0	return false;
226	0	}
227
228		/* If general purpose bits 1 & 2 are both zero, write real uncompressed size in header. */
229	0	if ((attributes->valid & ZIP_FILE_ATTRIBUTES_GENERAL_PURPOSE_BIT_FLAGS) && (attributes->general_purpose_bit_mask & 0x6) == 0x6 && (attributes->general_purpose_bit_flags & 0x06) == 0 && (st->valid & ZIP_STAT_SIZE)) {
230	0	ctx->uncompresssed_size = st->size;
231	0	}
232	0	else {
233	0	ctx->uncompresssed_size = ZIP_UINT64_MAX;
234	0	}
235
236	0	return true;
237	0	}
238
239
240	0	static bool end(void *ud) {
241	0	struct ctx ctx = (struct ctx )ud;
242
243	0	lzma_end(&ctx->zstr);
244	0	return true;
245	0	}
246
247
248	0	static bool input(void ud, zip_uint8_t data, zip_uint64_t length) {
249	0	struct ctx ctx = (struct ctx )ud;
250
251	0	if (length > UINT_MAX \|\| ctx->zstr.avail_in > 0) {
252	0	zip_error_set(ctx->error, ZIP_ER_INVAL, 0);
253	0	return false;
254	0	}
255
256		/* For decompression of LZMA1: Have we read the full "lzma alone" header yet? */
257	0	if (ctx->method == ZIP_CM_LZMA && !ctx->compress && ctx->header_state == INCOMPLETE) {
258		/* if not, get more of the data */
259	0	zip_uint8_t got = (zip_uint8_t)ZIP_MIN(HEADER_BYTES_ZIP - ctx->header_bytes_offset, length);
260	0	(void)memcpy_s(ctx->header + ctx->header_bytes_offset, sizeof(ctx->header) - ctx->header_bytes_offset, data, got);
261	0	ctx->header_bytes_offset += got;
262	0	length -= got;
263	0	data += got;
264		/* Do we have a complete header now? */
265	0	if (ctx->header_bytes_offset == HEADER_BYTES_ZIP) {
266	0	Bytef empty_buffer[1];
267	0	zip_buffer_t *buffer;
268		/* check magic */
269	0	if (ctx->header[HEADER_MAGIC2_OFFSET] != 0x05 \|\| ctx->header[HEADER_MAGIC2_OFFSET + 1] != 0x00) {
270		/* magic does not match */
271	0	zip_error_set(ctx->error, ZIP_ER_COMPRESSED_DATA, 0);
272	0	return false;
273	0	}
274		/* set size of uncompressed data in "lzma alone" header to "unknown" */
275	0	if ((buffer = _zip_buffer_new(ctx->header + HEADER_SIZE_OFFSET, HEADER_SIZE_LENGTH)) == NULL) {
276	0	zip_error_set(ctx->error, ZIP_ER_MEMORY, 0);
277	0	return false;
278	0	}
279	0	_zip_buffer_put_64(buffer, ctx->uncompresssed_size);
280	0	_zip_buffer_free(buffer);
281		/* Feed header into "lzma alone" decoder, for
282		* initialization; this should not produce output. */
283	0	ctx->zstr.next_in = (void *)(ctx->header + HEADER_MAGIC_LENGTH);
284	0	ctx->zstr.avail_in = HEADER_LZMA_ALONE_LENGTH;
285	0	ctx->zstr.total_in = 0;
286	0	ctx->zstr.next_out = empty_buffer;
287	0	ctx->zstr.avail_out = sizeof(*empty_buffer);
288	0	ctx->zstr.total_out = 0;
289		/* this just initializes the decoder and does not produce output, so it consumes the complete header */
290	0	if (lzma_code(&ctx->zstr, LZMA_RUN) != LZMA_OK \|\| ctx->zstr.total_out > 0) {
291	0	zip_error_set(ctx->error, ZIP_ER_COMPRESSED_DATA, 0);
292	0	return false;
293	0	}
294	0	ctx->header_state = DONE;
295	0	}
296	0	}
297	0	ctx->zstr.avail_in = (uInt)length;
298	0	ctx->zstr.next_in = (Bytef *)data;
299
300	0	return true;
301	0	}
302
303
304	0	static bool end_of_input(void *ud) {
305	0	struct ctx ctx = (struct ctx )ud;
306
307	0	ctx->end_of_input = true;
308	0	return ctx->zstr.avail_in != 0;
309	0	}
310
311
312	0	static zip_compression_status_t process(void ud, zip_uint8_t data, zip_uint64_t *length) {
313	0	struct ctx ctx = (struct ctx )ud;
314	0	uInt avail_out;
315	0	lzma_ret ret;
316		/* for compression of LZMA1 */
317	0	if (ctx->method == ZIP_CM_LZMA && ctx->compress) {
318	0	if (ctx->header_state == INCOMPLETE) {
319		/* write magic to output buffer */
320	0	ctx->header[0] = 0x09;
321	0	ctx->header[1] = 0x14;
322	0	ctx->header[2] = 0x05;
323	0	ctx->header[3] = 0x00;
324		/* generate lzma parameters into output buffer */
325	0	ctx->zstr.avail_out = HEADER_LZMA_ALONE_LENGTH;
326	0	ctx->zstr.next_out = ctx->header + HEADER_MAGIC_LENGTH;
327	0	ret = lzma_code(&ctx->zstr, LZMA_RUN);
328	0	if (ret != LZMA_OK \|\| ctx->zstr.avail_out != 0) {
329		/* assume that the whole header will be provided with the first call to lzma_code */
330	0	return ZIP_COMPRESSION_ERROR;
331	0	}
332	0	ctx->header_state = OUTPUT;
333	0	}
334	0	if (ctx->header_state == OUTPUT) {
335		/* write header */
336	0	zip_uint8_t write_len = (zip_uint8_t)ZIP_MIN(HEADER_BYTES_ZIP - ctx->header_bytes_offset, *length);
337	0	(void)memcpy_s(data, *length, ctx->header + ctx->header_bytes_offset, write_len);
338	0	ctx->header_bytes_offset += write_len;
339	0	*length = write_len;
340	0	if (ctx->header_bytes_offset == HEADER_BYTES_ZIP) {
341	0	ctx->header_state = DONE;
342	0	}
343	0	return ZIP_COMPRESSION_OK;
344	0	}
345	0	}
346
347	0	avail_out = (uInt)ZIP_MIN(UINT_MAX, *length);
348	0	ctx->zstr.avail_out = avail_out;
349	0	ctx->zstr.next_out = (Bytef *)data;
350
351	0	ret = lzma_code(&ctx->zstr, ctx->end_of_input ? LZMA_FINISH : LZMA_RUN);
352	0	*length = avail_out - ctx->zstr.avail_out;
353
354	0	switch (ret) {
355	0	case LZMA_OK:
356	0	return ZIP_COMPRESSION_OK;
357
358	0	case LZMA_STREAM_END:
359	0	return ZIP_COMPRESSION_END;
360
361	0	case LZMA_BUF_ERROR:
362	0	if (ctx->zstr.avail_in == 0) {
363	0	return ZIP_COMPRESSION_NEED_DATA;
364	0	}
365
366		/* fallthrough */
367	0	default:
368	0	zip_error_set(ctx->error, map_error(ret), 0);
369	0	return ZIP_COMPRESSION_ERROR;
370	0	}
371	0	}
372
373		/* Version Required should be set to 63 (6.3) because this compression
374		method was only defined in appnote.txt version 6.3.8, but Winzip
375		does not unpack it if the value is not 20. */
376
377		/* clang-format off */
378
379		zip_compression_algorithm_t zip_algorithm_xz_compress = {
380		maximum_compressed_size,
381		compress_allocate,
382		deallocate,
383		general_purpose_bit_flags,
384		20,
385		start,
386		end,
387		input,
388		end_of_input,
389		process
390		};
391
392
393		zip_compression_algorithm_t zip_algorithm_xz_decompress = {
394		maximum_compressed_size,
395		decompress_allocate,
396		deallocate,
397		general_purpose_bit_flags,
398		20,
399		start,
400		end,
401		input,
402		end_of_input,
403		process
404		};
405
406		/* clang-format on */