/src/libzip/lib/zip_source_compress.c

Source
/*
  zip_source_compress.c -- (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 <stdlib.h>
#include <string.h>

struct context {
    zip_error_t error;

    bool end_of_input;
    bool end_of_stream;
    bool can_store;
    bool is_stored; /* only valid if end_of_stream is true */
    bool compress;
    bool check_consistency;
    zip_int32_t method;

    zip_uint64_t size;
    zip_int64_t first_read;
    zip_uint8_t buffer[BUFSIZE];

    zip_compression_algorithm_t *algorithm;
    void *ud;
};


struct implementation {
    zip_uint16_t method;
    zip_compression_algorithm_t *compress;
    zip_compression_algorithm_t *decompress;
};

static struct implementation implementations[] = {
    {ZIP_CM_DEFLATE, &zip_algorithm_deflate_compress, &zip_algorithm_deflate_decompress},
#if defined(HAVE_LIBBZ2)
    {ZIP_CM_BZIP2, &zip_algorithm_bzip2_compress, &zip_algorithm_bzip2_decompress},
#endif
#if defined(HAVE_LIBLZMA)
    {ZIP_CM_LZMA, &zip_algorithm_xz_compress, &zip_algorithm_xz_decompress},
    /*  Disabled - because 7z isn't able to unpack ZIP+LZMA2
        archives made this way - and vice versa.

        {ZIP_CM_LZMA2, &zip_algorithm_xz_compress, &zip_algorithm_xz_decompress},
    */
    {ZIP_CM_XZ, &zip_algorithm_xz_compress, &zip_algorithm_xz_decompress},
#endif
#if defined(HAVE_LIBZSTD)
    {ZIP_CM_ZSTD, &zip_algorithm_zstd_compress, &zip_algorithm_zstd_decompress},
#endif

};

static size_t implementations_size = sizeof(implementations) / sizeof(implementations[0]);

static zip_source_t *compression_source_new(zip_t *za, zip_source_t *src, zip_int32_t method, bool compress, zip_uint32_t compression_flags);
static zip_int64_t compress_callback(zip_source_t *, void *, void *, zip_uint64_t, zip_source_cmd_t);
static void context_free(struct context *ctx);
static struct context *context_new(zip_int32_t method, bool compress, zip_uint32_t compression_flags, zip_compression_algorithm_t *algorithm, bool check_consistency);
static zip_int64_t compress_read(zip_source_t *, struct context *, void *, zip_uint64_t);

zip_compression_algorithm_t *_zip_get_compression_algorithm(zip_int32_t method, bool compress) {
    size_t i;
    zip_uint16_t real_method = ZIP_CM_ACTUAL(method);

    for (i = 0; i < implementations_size; i++) {
        if (implementations[i].method == real_method) {
            if (compress) {
                return implementations[i].compress;
            }
            else {
                return implementations[i].decompress;
            }
        }
    }

    return NULL;
}

ZIP_EXTERN int zip_compression_method_supported(zip_int32_t method, int compress) {
    if (method == ZIP_CM_STORE) {
        return 1;
    }
    return _zip_get_compression_algorithm(method, compress) != NULL;
}

zip_source_t *zip_source_compress(zip_t *za, zip_source_t *src, zip_int32_t method, zip_uint32_t compression_flags) {
    return compression_source_new(za, src, method, true, compression_flags);
}

zip_source_t *zip_source_decompress(zip_t *za, zip_source_t *src, zip_int32_t method) {
    return compression_source_new(za, src, method, false, 0);
}


static zip_source_t *compression_source_new(zip_t *za, zip_source_t *src, zip_int32_t method, bool compress, zip_uint32_t compression_flags) {
    struct context *ctx;
    zip_source_t *s2;
    zip_compression_algorithm_t *algorithm = NULL;

    if (src == NULL) {
        zip_error_set(&za->error, ZIP_ER_INVAL, 0);
        return NULL;
    }

    if ((algorithm = _zip_get_compression_algorithm(method, compress)) == NULL) {
        zip_error_set(&za->error, ZIP_ER_COMPNOTSUPP, 0);
        return NULL;
    }

    if ((ctx = context_new(method, compress, compression_flags, algorithm, za->open_flags & ZIP_CHECKCONS)) == NULL) {
        zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
        return NULL;
    }

    if ((s2 = zip_source_layered(za, src, compress_callback, ctx)) == NULL) {
        context_free(ctx);
        return NULL;
    }

    return s2;
}


static struct context *context_new(zip_int32_t method, bool compress, zip_uint32_t compression_flags, zip_compression_algorithm_t *algorithm, bool check_consistency) {
    struct context *ctx;

    if ((ctx = (struct context *)malloc(sizeof(*ctx))) == NULL) {
        return NULL;
    }
    zip_error_init(&ctx->error);
    ctx->can_store = compress ? method == ZIP_CM_DEFAULT : false;
    ctx->algorithm = algorithm;
    ctx->method = method;
    ctx->compress = compress;
    ctx->end_of_input = false;
    ctx->end_of_stream = false;
    ctx->is_stored = false;
    ctx->check_consistency = check_consistency;

    if ((ctx->ud = ctx->algorithm->allocate(ZIP_CM_ACTUAL(method), compression_flags, &ctx->error)) == NULL) {
        zip_error_fini(&ctx->error);
        free(ctx);
        return NULL;
    }

    return ctx;
}


static void context_free(struct context *ctx) {
    if (ctx == NULL) {
        return;
    }

    ctx->algorithm->deallocate(ctx->ud);
    zip_error_fini(&ctx->error);

    free(ctx);
}


static zip_int64_t compress_read(zip_source_t *src, struct context *ctx, void *data, zip_uint64_t len) {
    zip_compression_status_t ret;
    bool end;
    zip_int64_t n;
    zip_uint64_t out_offset;
    zip_uint64_t out_len;

    if (zip_error_code_zip(&ctx->error) != ZIP_ER_OK) {
        return -1;
    }

    if (len == 0 || ctx->end_of_stream) {
        return 0;
    }

    out_offset = 0;

    end = false;
    while (!end && out_offset < len) {
        out_len = len - out_offset;
        ret = ctx->algorithm->process(ctx->ud, (zip_uint8_t *)data + out_offset, &out_len);

        if (ret != ZIP_COMPRESSION_ERROR) {
            out_offset += out_len;
        }

        switch (ret) {
        case ZIP_COMPRESSION_END:
            ctx->end_of_stream = true;

            if (!ctx->end_of_input) {
                n = zip_source_read(src, ctx->buffer, 1);
                if (n < 0) {
                    zip_error_set_from_source(&ctx->error, src);
                    end = true;
                    break;
                }
                else if (n == 0) {
                    ctx->end_of_input = true;
                    n = ctx->algorithm->end_of_input(ctx->ud) ? 1 : 0;
                }

                if (n > 0 && ctx->check_consistency) {
                    /* garbage after stream, or compression ended before all data read */
                    zip_error_set(&ctx->error, ZIP_ER_INCONS, ZIP_ER_DETAIL_COMPRESSED_DATA_TRAILING_GARBAGE);
                    end = true;
                    break;
                }
            }

            if (ctx->first_read < 0) {
                /* we got end of processed stream before reading any input data */
                zip_error_set(&ctx->error, ZIP_ER_INTERNAL, 0);
                end = true;
                break;
            }
            if (ctx->can_store && (zip_uint64_t)ctx->first_read <= out_offset) {
                ctx->is_stored = true;
                ctx->size = (zip_uint64_t)ctx->first_read;
                (void)memcpy_s(data, ctx->size, ctx->buffer, ctx->size);
                return (zip_int64_t)ctx->size;
            }
            end = true;
            break;

        case ZIP_COMPRESSION_OK:
            break;

        case ZIP_COMPRESSION_NEED_DATA:
            if (ctx->end_of_input) {
                /* TODO: error: stream not ended, but no more input */
                end = true;
                break;
            }

            if ((n = zip_source_read(src, ctx->buffer, sizeof(ctx->buffer))) < 0) {
                zip_error_set_from_source(&ctx->error, src);
                end = true;
                break;
            }
            else if (n == 0) {
                ctx->end_of_input = true;
                ctx->algorithm->end_of_input(ctx->ud);
                if (ctx->first_read < 0) {
                    ctx->first_read = 0;
                }
            }
            else {
                if (ctx->first_read >= 0) {
                    /* we overwrote a previously filled ctx->buffer */
                    ctx->can_store = false;
                }
                else {
                    ctx->first_read = n;
                }

                ctx->algorithm->input(ctx->ud, ctx->buffer, (zip_uint64_t)n);
            }
            break;

        case ZIP_COMPRESSION_ERROR:
            /* error set by algorithm */
            if (zip_error_code_zip(&ctx->error) == ZIP_ER_OK) {
                zip_error_set(&ctx->error, ZIP_ER_INTERNAL, 0);
            }
            end = true;
            break;
        }
    }

    if (out_offset > 0) {
        ctx->can_store = false;
        ctx->size += out_offset;
        return (zip_int64_t)out_offset;
    }

    return (zip_error_code_zip(&ctx->error) == ZIP_ER_OK) ? 0 : -1;
}


static zip_int64_t compress_callback(zip_source_t *src, void *ud, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
    struct context *ctx;

    ctx = (struct context *)ud;

    switch (cmd) {
    case ZIP_SOURCE_OPEN: {
        zip_stat_t st;
        zip_file_attributes_t attributes;

        ctx->size = 0;
        ctx->end_of_input = false;
        ctx->end_of_stream = false;
        ctx->is_stored = false;
        ctx->first_read = -1;

        if (zip_source_stat(src, &st) < 0 || zip_source_get_file_attributes(src, &attributes) < 0) {
            zip_error_set_from_source(&ctx->error, src);
            return -1;
        }

        if (!ctx->algorithm->start(ctx->ud, &st, &attributes)) {
            return -1;
        }

        return 0;
    }

    case ZIP_SOURCE_READ:
        return compress_read(src, ctx, data, len);

    case ZIP_SOURCE_CLOSE:
        if (!ctx->algorithm->end(ctx->ud)) {
            return -1;
        }
        return 0;

    case ZIP_SOURCE_STAT: {
        zip_stat_t *st;

        st = (zip_stat_t *)data;

        if (ctx->compress) {
            if (ctx->end_of_stream) {
                st->comp_method = ctx->is_stored ? ZIP_CM_STORE : ZIP_CM_ACTUAL(ctx->method);
                st->comp_size = ctx->size;
                st->valid |= ZIP_STAT_COMP_SIZE | ZIP_STAT_COMP_METHOD;
            }
            else {
                st->valid &= ~(ZIP_STAT_COMP_SIZE | ZIP_STAT_COMP_METHOD);
            }
        }
        else {
            st->comp_method = ZIP_CM_STORE;
            st->valid |= ZIP_STAT_COMP_METHOD;
            st->valid &= ~ZIP_STAT_COMP_SIZE;
            if (ctx->end_of_stream) {
                st->size = ctx->size;
                st->valid |= ZIP_STAT_SIZE;
            }
        }
    }
        return 0;

    case ZIP_SOURCE_ERROR:
        return zip_error_to_data(&ctx->error, data, len);

    case ZIP_SOURCE_FREE:
        context_free(ctx);
        return 0;

    case ZIP_SOURCE_GET_FILE_ATTRIBUTES: {
        zip_file_attributes_t *attributes = (zip_file_attributes_t *)data;

        if (len < sizeof(*attributes)) {
            zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
            return -1;
        }

        attributes->valid |= ZIP_FILE_ATTRIBUTES_VERSION_NEEDED | ZIP_FILE_ATTRIBUTES_GENERAL_PURPOSE_BIT_FLAGS;
        attributes->version_needed = ctx->algorithm->version_needed;
        attributes->general_purpose_bit_mask = ZIP_FILE_ATTRIBUTES_GENERAL_PURPOSE_BIT_FLAGS_ALLOWED_MASK;
        attributes->general_purpose_bit_flags = (ctx->is_stored ? 0 : ctx->algorithm->general_purpose_bit_flags(ctx->ud));

        return sizeof(*attributes);
    }

    case ZIP_SOURCE_SUPPORTS:
        return ZIP_SOURCE_SUPPORTS_READABLE | zip_source_make_command_bitmap(ZIP_SOURCE_GET_FILE_ATTRIBUTES, ZIP_SOURCE_SUPPORTS_REOPEN, -1);

    default:
        return zip_source_pass_to_lower_layer(src, data, len, cmd);
    }
}

Coverage Report

Created: 2026-04-01 07:49

Line	Count	Source
1		/*
2		zip_source_compress.c -- (de)compression routines
3		Copyright (C) 2017-2025 Dieter Baron and Thomas Klausner
4
5		This file is part of libzip, a library to manipulate ZIP archives.
6		The authors can be contacted at <info@libzip.org>
7
8		Redistribution and use in source and binary forms, with or without
9		modification, are permitted provided that the following conditions
10		are met:
11		1. Redistributions of source code must retain the above copyright
12		notice, this list of conditions and the following disclaimer.
13		2. Redistributions in binary form must reproduce the above copyright
14		notice, this list of conditions and the following disclaimer in
15		the documentation and/or other materials provided with the
16		distribution.
17		3. The names of the authors may not be used to endorse or promote
18		products derived from this software without specific prior
19		written permission.
20
21		THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
22		OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23		WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24		ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
25		DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26		DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27		GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28		INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
29		IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30		OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
31		IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32		*/
33
34		#include "zipint.h"
35
36		#include <stdlib.h>
37		#include <string.h>
38
39		struct context {
40		zip_error_t error;
41
42		bool end_of_input;
43		bool end_of_stream;
44		bool can_store;
45		bool is_stored; /* only valid if end_of_stream is true */
46		bool compress;
47		bool check_consistency;
48		zip_int32_t method;
49
50		zip_uint64_t size;
51		zip_int64_t first_read;
52		zip_uint8_t buffer[BUFSIZE];
53
54		zip_compression_algorithm_t *algorithm;
55		void *ud;
56		};
57
58
59		struct implementation {
60		zip_uint16_t method;
61		zip_compression_algorithm_t *compress;
62		zip_compression_algorithm_t *decompress;
63		};
64
65		static struct implementation implementations[] = {
66		{ZIP_CM_DEFLATE, &zip_algorithm_deflate_compress, &zip_algorithm_deflate_decompress},
67		#if defined(HAVE_LIBBZ2)
68		{ZIP_CM_BZIP2, &zip_algorithm_bzip2_compress, &zip_algorithm_bzip2_decompress},
69		#endif
70		#if defined(HAVE_LIBLZMA)
71		{ZIP_CM_LZMA, &zip_algorithm_xz_compress, &zip_algorithm_xz_decompress},
72		/* Disabled - because 7z isn't able to unpack ZIP+LZMA2
73		archives made this way - and vice versa.
74
75		{ZIP_CM_LZMA2, &zip_algorithm_xz_compress, &zip_algorithm_xz_decompress},
76		*/
77		{ZIP_CM_XZ, &zip_algorithm_xz_compress, &zip_algorithm_xz_decompress},
78		#endif
79		#if defined(HAVE_LIBZSTD)
80		{ZIP_CM_ZSTD, &zip_algorithm_zstd_compress, &zip_algorithm_zstd_decompress},
81		#endif
82
83		};
84
85		static size_t implementations_size = sizeof(implementations) / sizeof(implementations[0]);
86
87		static zip_source_t compression_source_new(zip_t za, zip_source_t *src, zip_int32_t method, bool compress, zip_uint32_t compression_flags);
88		static zip_int64_t compress_callback(zip_source_t , void , void *, zip_uint64_t, zip_source_cmd_t);
89		static void context_free(struct context *ctx);
90		static struct context context_new(zip_int32_t method, bool compress, zip_uint32_t compression_flags, zip_compression_algorithm_t algorithm, bool check_consistency);
91		static zip_int64_t compress_read(zip_source_t , struct context , void *, zip_uint64_t);
92
93	0	zip_compression_algorithm_t *_zip_get_compression_algorithm(zip_int32_t method, bool compress) {
94	0	size_t i;
95	0	zip_uint16_t real_method = ZIP_CM_ACTUAL(method);
96
97	0	for (i = 0; i < implementations_size; i++) {
98	0	if (implementations[i].method == real_method) {
99	0	if (compress) {
100	0	return implementations[i].compress;
101	0	}
102	0	else {
103	0	return implementations[i].decompress;
104	0	}
105	0	}
106	0	}
107
108	0	return NULL;
109	0	}
110
111	0	ZIP_EXTERN int zip_compression_method_supported(zip_int32_t method, int compress) {
112	0	if (method == ZIP_CM_STORE) {
113	0	return 1;
114	0	}
115	0	return _zip_get_compression_algorithm(method, compress) != NULL;
116	0	}
117
118	0	zip_source_t zip_source_compress(zip_t za, zip_source_t *src, zip_int32_t method, zip_uint32_t compression_flags) {
119	0	return compression_source_new(za, src, method, true, compression_flags);
120	0	}
121
122	0	zip_source_t zip_source_decompress(zip_t za, zip_source_t *src, zip_int32_t method) {
123	0	return compression_source_new(za, src, method, false, 0);
124	0	}
125
126
127	0	static zip_source_t compression_source_new(zip_t za, zip_source_t *src, zip_int32_t method, bool compress, zip_uint32_t compression_flags) {
128	0	struct context *ctx;
129	0	zip_source_t *s2;
130	0	zip_compression_algorithm_t *algorithm = NULL;
131
132	0	if (src == NULL) {
133	0	zip_error_set(&za->error, ZIP_ER_INVAL, 0);
134	0	return NULL;
135	0	}
136
137	0	if ((algorithm = _zip_get_compression_algorithm(method, compress)) == NULL) {
138	0	zip_error_set(&za->error, ZIP_ER_COMPNOTSUPP, 0);
139	0	return NULL;
140	0	}
141
142	0	if ((ctx = context_new(method, compress, compression_flags, algorithm, za->open_flags & ZIP_CHECKCONS)) == NULL) {
143	0	zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
144	0	return NULL;
145	0	}
146
147	0	if ((s2 = zip_source_layered(za, src, compress_callback, ctx)) == NULL) {
148	0	context_free(ctx);
149	0	return NULL;
150	0	}
151
152	0	return s2;
153	0	}
154
155
156	0	static struct context context_new(zip_int32_t method, bool compress, zip_uint32_t compression_flags, zip_compression_algorithm_t algorithm, bool check_consistency) {
157	0	struct context *ctx;
158
159	0	if ((ctx = (struct context )malloc(sizeof(ctx))) == NULL) {
160	0	return NULL;
161	0	}
162	0	zip_error_init(&ctx->error);
163	0	ctx->can_store = compress ? method == ZIP_CM_DEFAULT : false;
164	0	ctx->algorithm = algorithm;
165	0	ctx->method = method;
166	0	ctx->compress = compress;
167	0	ctx->end_of_input = false;
168	0	ctx->end_of_stream = false;
169	0	ctx->is_stored = false;
170	0	ctx->check_consistency = check_consistency;
171
172	0	if ((ctx->ud = ctx->algorithm->allocate(ZIP_CM_ACTUAL(method), compression_flags, &ctx->error)) == NULL) {
173	0	zip_error_fini(&ctx->error);
174	0	free(ctx);
175	0	return NULL;
176	0	}
177
178	0	return ctx;
179	0	}
180
181
182	0	static void context_free(struct context *ctx) {
183	0	if (ctx == NULL) {
184	0	return;
185	0	}
186
187	0	ctx->algorithm->deallocate(ctx->ud);
188	0	zip_error_fini(&ctx->error);
189
190	0	free(ctx);
191	0	}
192
193
194	0	static zip_int64_t compress_read(zip_source_t src, struct context ctx, void *data, zip_uint64_t len) {
195	0	zip_compression_status_t ret;
196	0	bool end;
197	0	zip_int64_t n;
198	0	zip_uint64_t out_offset;
199	0	zip_uint64_t out_len;
200
201	0	if (zip_error_code_zip(&ctx->error) != ZIP_ER_OK) {
202	0	return -1;
203	0	}
204
205	0	if (len == 0 \|\| ctx->end_of_stream) {
206	0	return 0;
207	0	}
208
209	0	out_offset = 0;
210
211	0	end = false;
212	0	while (!end && out_offset < len) {
213	0	out_len = len - out_offset;
214	0	ret = ctx->algorithm->process(ctx->ud, (zip_uint8_t *)data + out_offset, &out_len);
215
216	0	if (ret != ZIP_COMPRESSION_ERROR) {
217	0	out_offset += out_len;
218	0	}
219
220	0	switch (ret) {
221	0	case ZIP_COMPRESSION_END:
222	0	ctx->end_of_stream = true;
223
224	0	if (!ctx->end_of_input) {
225	0	n = zip_source_read(src, ctx->buffer, 1);
226	0	if (n < 0) {
227	0	zip_error_set_from_source(&ctx->error, src);
228	0	end = true;
229	0	break;
230	0	}
231	0	else if (n == 0) {
232	0	ctx->end_of_input = true;
233	0	n = ctx->algorithm->end_of_input(ctx->ud) ? 1 : 0;
234	0	}
235
236	0	if (n > 0 && ctx->check_consistency) {
237		/* garbage after stream, or compression ended before all data read */
238	0	zip_error_set(&ctx->error, ZIP_ER_INCONS, ZIP_ER_DETAIL_COMPRESSED_DATA_TRAILING_GARBAGE);
239	0	end = true;
240	0	break;
241	0	}
242	0	}
243
244	0	if (ctx->first_read < 0) {
245		/* we got end of processed stream before reading any input data */
246	0	zip_error_set(&ctx->error, ZIP_ER_INTERNAL, 0);
247	0	end = true;
248	0	break;
249	0	}
250	0	if (ctx->can_store && (zip_uint64_t)ctx->first_read <= out_offset) {
251	0	ctx->is_stored = true;
252	0	ctx->size = (zip_uint64_t)ctx->first_read;
253	0	(void)memcpy_s(data, ctx->size, ctx->buffer, ctx->size);
254	0	return (zip_int64_t)ctx->size;
255	0	}
256	0	end = true;
257	0	break;
258
259	0	case ZIP_COMPRESSION_OK:
260	0	break;
261
262	0	case ZIP_COMPRESSION_NEED_DATA:
263	0	if (ctx->end_of_input) {
264		/* TODO: error: stream not ended, but no more input */
265	0	end = true;
266	0	break;
267	0	}
268
269	0	if ((n = zip_source_read(src, ctx->buffer, sizeof(ctx->buffer))) < 0) {
270	0	zip_error_set_from_source(&ctx->error, src);
271	0	end = true;
272	0	break;
273	0	}
274	0	else if (n == 0) {
275	0	ctx->end_of_input = true;
276	0	ctx->algorithm->end_of_input(ctx->ud);
277	0	if (ctx->first_read < 0) {
278	0	ctx->first_read = 0;
279	0	}
280	0	}
281	0	else {
282	0	if (ctx->first_read >= 0) {
283		/* we overwrote a previously filled ctx->buffer */
284	0	ctx->can_store = false;
285	0	}
286	0	else {
287	0	ctx->first_read = n;
288	0	}
289
290	0	ctx->algorithm->input(ctx->ud, ctx->buffer, (zip_uint64_t)n);
291	0	}
292	0	break;
293
294	0	case ZIP_COMPRESSION_ERROR:
295		/* error set by algorithm */
296	0	if (zip_error_code_zip(&ctx->error) == ZIP_ER_OK) {
297	0	zip_error_set(&ctx->error, ZIP_ER_INTERNAL, 0);
298	0	}
299	0	end = true;
300	0	break;
301	0	}
302	0	}
303
304	0	if (out_offset > 0) {
305	0	ctx->can_store = false;
306	0	ctx->size += out_offset;
307	0	return (zip_int64_t)out_offset;
308	0	}
309
310	0	return (zip_error_code_zip(&ctx->error) == ZIP_ER_OK) ? 0 : -1;
311	0	}
312
313
314	0	static zip_int64_t compress_callback(zip_source_t src, void ud, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
315	0	struct context *ctx;
316
317	0	ctx = (struct context *)ud;
318
319	0	switch (cmd) {
320	0	case ZIP_SOURCE_OPEN: {
321	0	zip_stat_t st;
322	0	zip_file_attributes_t attributes;
323
324	0	ctx->size = 0;
325	0	ctx->end_of_input = false;
326	0	ctx->end_of_stream = false;
327	0	ctx->is_stored = false;
328	0	ctx->first_read = -1;
329
330	0	if (zip_source_stat(src, &st) < 0 \|\| zip_source_get_file_attributes(src, &attributes) < 0) {
331	0	zip_error_set_from_source(&ctx->error, src);
332	0	return -1;
333	0	}
334
335	0	if (!ctx->algorithm->start(ctx->ud, &st, &attributes)) {
336	0	return -1;
337	0	}
338
339	0	return 0;
340	0	}
341
342	0	case ZIP_SOURCE_READ:
343	0	return compress_read(src, ctx, data, len);
344
345	0	case ZIP_SOURCE_CLOSE:
346	0	if (!ctx->algorithm->end(ctx->ud)) {
347	0	return -1;
348	0	}
349	0	return 0;
350
351	0	case ZIP_SOURCE_STAT: {
352	0	zip_stat_t *st;
353
354	0	st = (zip_stat_t *)data;
355
356	0	if (ctx->compress) {
357	0	if (ctx->end_of_stream) {
358	0	st->comp_method = ctx->is_stored ? ZIP_CM_STORE : ZIP_CM_ACTUAL(ctx->method);
359	0	st->comp_size = ctx->size;
360	0	st->valid \|= ZIP_STAT_COMP_SIZE \| ZIP_STAT_COMP_METHOD;
361	0	}
362	0	else {
363	0	st->valid &= ~(ZIP_STAT_COMP_SIZE \| ZIP_STAT_COMP_METHOD);
364	0	}
365	0	}
366	0	else {
367	0	st->comp_method = ZIP_CM_STORE;
368	0	st->valid \|= ZIP_STAT_COMP_METHOD;
369	0	st->valid &= ~ZIP_STAT_COMP_SIZE;
370	0	if (ctx->end_of_stream) {
371	0	st->size = ctx->size;
372	0	st->valid \|= ZIP_STAT_SIZE;
373	0	}
374	0	}
375	0	}
376	0	return 0;
377
378	0	case ZIP_SOURCE_ERROR:
379	0	return zip_error_to_data(&ctx->error, data, len);
380
381	0	case ZIP_SOURCE_FREE:
382	0	context_free(ctx);
383	0	return 0;
384
385	0	case ZIP_SOURCE_GET_FILE_ATTRIBUTES: {
386	0	zip_file_attributes_t attributes = (zip_file_attributes_t )data;
387
388	0	if (len < sizeof(*attributes)) {
389	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
390	0	return -1;
391	0	}
392
393	0	attributes->valid \|= ZIP_FILE_ATTRIBUTES_VERSION_NEEDED \| ZIP_FILE_ATTRIBUTES_GENERAL_PURPOSE_BIT_FLAGS;
394	0	attributes->version_needed = ctx->algorithm->version_needed;
395	0	attributes->general_purpose_bit_mask = ZIP_FILE_ATTRIBUTES_GENERAL_PURPOSE_BIT_FLAGS_ALLOWED_MASK;
396	0	attributes->general_purpose_bit_flags = (ctx->is_stored ? 0 : ctx->algorithm->general_purpose_bit_flags(ctx->ud));
397
398	0	return sizeof(*attributes);
399	0	}
400
401	0	case ZIP_SOURCE_SUPPORTS:
402	0	return ZIP_SOURCE_SUPPORTS_READABLE \| zip_source_make_command_bitmap(ZIP_SOURCE_GET_FILE_ATTRIBUTES, ZIP_SOURCE_SUPPORTS_REOPEN, -1);
403
404	0	default:
405	0	return zip_source_pass_to_lower_layer(src, data, len, cmd);
406	0	}
407	0	}