/src/libzip/lib/zip_algorithm_deflate.c

Source
/*
  zip_algorithm_deflate.c -- deflate (de)compression routines
  Copyright (C) 2017-2023 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 <stdlib.h>
#include <zlib.h>

struct ctx {
    zip_error_t *error;
    bool compress;
    int level;
    int mem_level;
    bool end_of_input;
    z_stream zstr;
};


static zip_uint64_t
maximum_compressed_size(zip_uint64_t uncompressed_size) {
    /* max deflate size increase: size + ceil(size/16k)*5+6 */

    zip_uint64_t compressed_size = uncompressed_size + (uncompressed_size + 16383) / 16384 * 5 + 6;

    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) {
    struct ctx *ctx;

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

    ctx->error = error;
    ctx->compress = compress;
    if (compression_flags >= 1 && compression_flags <= 9) {
        ctx->level = (int)compression_flags;
    }
    else {
        ctx->level = Z_BEST_COMPRESSION;
    }
    ctx->mem_level = compression_flags == TORRENTZIP_COMPRESSION_FLAGS ? TORRENTZIP_MEM_LEVEL : MAX_MEM_LEVEL;
    ctx->end_of_input = false;

    ctx->zstr.zalloc = Z_NULL;
    ctx->zstr.zfree = Z_NULL;
    ctx->zstr.opaque = NULL;

    return ctx;
}


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


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


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->level < 3) {
        return 2 << 1;
    }
    else if (ctx->level > 7) {
        return 1 << 1;
    }
    return 0;
}


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

    (void)st;
    (void)attributes;

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

    if (ctx->compress) {
        /* negative value to tell zlib not to write a header */
        ret = deflateInit2(&ctx->zstr, ctx->level, Z_DEFLATED, -MAX_WBITS, ctx->mem_level, Z_DEFAULT_STRATEGY);
    }
    else {
        ret = inflateInit2(&ctx->zstr, -MAX_WBITS);
    }

    if (ret != Z_OK) {
        zip_error_set(ctx->error, ZIP_ER_ZLIB, ret);
        return false;
    }


    return true;
}


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

    if (ctx->compress) {
        err = deflateEnd(&ctx->zstr);
    }
    else {
        err = inflateEnd(&ctx->zstr);
    }

    if (err != Z_OK) {
        zip_error_set(ctx->error, ZIP_ER_ZLIB, err);
        return false;
    }

    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;
    }

    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;

    int ret;

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

    if (ctx->compress) {
        ret = deflate(&ctx->zstr, ctx->end_of_input ? Z_FINISH : 0);
    }
    else {
        ret = inflate(&ctx->zstr, Z_SYNC_FLUSH);
    }

    *length = avail_out - ctx->zstr.avail_out;

    switch (ret) {
    case Z_OK:
        return ZIP_COMPRESSION_OK;

    case Z_STREAM_END:
        return ZIP_COMPRESSION_END;

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

        /* fallthrough */

    default:
        zip_error_set(ctx->error, ZIP_ER_ZLIB, ret);
        return ZIP_COMPRESSION_ERROR;
    }
}

/* clang-format off */

zip_compression_algorithm_t zip_algorithm_deflate_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_deflate_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: 2025-10-28 07:10

Line	Count	Source
1		/*
2		zip_algorithm_deflate.c -- deflate (de)compression routines
3		Copyright (C) 2017-2023 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 <limits.h>
37		#include <stdlib.h>
38		#include <zlib.h>
39
40		struct ctx {
41		zip_error_t *error;
42		bool compress;
43		int level;
44		int mem_level;
45		bool end_of_input;
46		z_stream zstr;
47		};
48
49
50		static zip_uint64_t
51	939	maximum_compressed_size(zip_uint64_t uncompressed_size) {
52		/* max deflate size increase: size + ceil(size/16k)5+6 /
53
54	939	zip_uint64_t compressed_size = uncompressed_size + (uncompressed_size + 16383) / 16384 * 5 + 6;
55
56	939	if (compressed_size < uncompressed_size) {
57	0	return ZIP_UINT64_MAX;
58	0	}
59	939	return compressed_size;
60	939	}
61
62
63		static void *
64	19.7k	allocate(bool compress, zip_uint32_t compression_flags, zip_error_t *error) {
65	19.7k	struct ctx *ctx;
66
67	19.7k	if ((ctx = (struct ctx )malloc(sizeof(ctx))) == NULL) {
68	0	zip_error_set(error, ZIP_ET_SYS, errno);
69	0	return NULL;
70	0	}
71
72	19.7k	ctx->error = error;
73	19.7k	ctx->compress = compress;
74	19.7k	if (compression_flags >= 1 && compression_flags <= 9) {
75	0	ctx->level = (int)compression_flags;
76	0	}
77	19.7k	else {
78	19.7k	ctx->level = Z_BEST_COMPRESSION;
79	19.7k	}
80	19.7k	ctx->mem_level = compression_flags == TORRENTZIP_COMPRESSION_FLAGS ? TORRENTZIP_MEM_LEVEL : MAX_MEM_LEVEL;
81	19.7k	ctx->end_of_input = false;
82
83	19.7k	ctx->zstr.zalloc = Z_NULL;
84	19.7k	ctx->zstr.zfree = Z_NULL;
85	19.7k	ctx->zstr.opaque = NULL;
86
87	19.7k	return ctx;
88	19.7k	}
89
90
91		static void *
92	939	compress_allocate(zip_uint16_t method, zip_uint32_t compression_flags, zip_error_t *error) {
93	939	(void)method;
94	939	return allocate(true, compression_flags, error);
95	939	}
96
97
98		static void *
99	18.7k	decompress_allocate(zip_uint16_t method, zip_uint32_t compression_flags, zip_error_t *error) {
100	18.7k	(void)method;
101	18.7k	return allocate(false, compression_flags, error);
102	18.7k	}
103
104
105		static void
106	19.7k	deallocate(void *ud) {
107	19.7k	struct ctx ctx = (struct ctx )ud;
108
109	19.7k	free(ctx);
110	19.7k	}
111
112
113		static zip_uint16_t
114	1.61k	general_purpose_bit_flags(void *ud) {
115	1.61k	struct ctx ctx = (struct ctx )ud;
116
117	1.61k	if (!ctx->compress) {
118	0	return 0;
119	0	}
120
121	1.61k	if (ctx->level < 3) {
122	0	return 2 << 1;
123	0	}
124	1.61k	else if (ctx->level > 7) {
125	1.61k	return 1 << 1;
126	1.61k	}
127	0	return 0;
128	1.61k	}
129
130
131		static bool
132	17.0k	start(void ud, zip_stat_t st, zip_file_attributes_t *attributes) {
133	17.0k	struct ctx ctx = (struct ctx )ud;
134	17.0k	int ret;
135
136	17.0k	(void)st;
137	17.0k	(void)attributes;
138
139	17.0k	ctx->zstr.avail_in = 0;
140	17.0k	ctx->zstr.next_in = NULL;
141	17.0k	ctx->zstr.avail_out = 0;
142	17.0k	ctx->zstr.next_out = NULL;
143
144	17.0k	if (ctx->compress) {
145		/* negative value to tell zlib not to write a header */
146	939	ret = deflateInit2(&ctx->zstr, ctx->level, Z_DEFLATED, -MAX_WBITS, ctx->mem_level, Z_DEFAULT_STRATEGY);
147	939	}
148	16.0k	else {
149	16.0k	ret = inflateInit2(&ctx->zstr, -MAX_WBITS);
150	16.0k	}
151
152	17.0k	if (ret != Z_OK) {
153	0	zip_error_set(ctx->error, ZIP_ER_ZLIB, ret);
154	0	return false;
155	0	}
156
157
158	17.0k	return true;
159	17.0k	}
160
161
162		static bool
163	17.0k	end(void *ud) {
164	17.0k	struct ctx ctx = (struct ctx )ud;
165	17.0k	int err;
166
167	17.0k	if (ctx->compress) {
168	939	err = deflateEnd(&ctx->zstr);
169	939	}
170	16.0k	else {
171	16.0k	err = inflateEnd(&ctx->zstr);
172	16.0k	}
173
174	17.0k	if (err != Z_OK) {
175	0	zip_error_set(ctx->error, ZIP_ER_ZLIB, err);
176	0	return false;
177	0	}
178
179	17.0k	return true;
180	17.0k	}
181
182
183		static bool
184	37.0k	input(void ud, zip_uint8_t data, zip_uint64_t length) {
185	37.0k	struct ctx ctx = (struct ctx )ud;
186
187	37.0k	if (length > UINT_MAX \|\| ctx->zstr.avail_in > 0) {
188	0	zip_error_set(ctx->error, ZIP_ER_INVAL, 0);
189	0	return false;
190	0	}
191
192	37.0k	ctx->zstr.avail_in = (uInt)length;
193	37.0k	ctx->zstr.next_in = (Bytef *)data;
194
195	37.0k	return true;
196	37.0k	}
197
198
199	4.74k	static bool end_of_input(void *ud) {
200	4.74k	struct ctx ctx = (struct ctx )ud;
201
202	4.74k	ctx->end_of_input = true;
203	4.74k	return ctx->zstr.avail_in != 0;
204	4.74k	}
205
206
207		static zip_compression_status_t
208	99.0k	process(void ud, zip_uint8_t data, zip_uint64_t *length) {
209	99.0k	struct ctx ctx = (struct ctx )ud;
210	99.0k	uInt avail_out;
211
212	99.0k	int ret;
213
214	99.0k	avail_out = (uInt)ZIP_MIN(UINT_MAX, *length);
215	99.0k	ctx->zstr.avail_out = avail_out;
216	99.0k	ctx->zstr.next_out = (Bytef *)data;
217
218	99.0k	if (ctx->compress) {
219	64.6k	ret = deflate(&ctx->zstr, ctx->end_of_input ? Z_FINISH : 0);
220	64.6k	}
221	34.3k	else {
222	34.3k	ret = inflate(&ctx->zstr, Z_SYNC_FLUSH);
223	34.3k	}
224
225	99.0k	*length = avail_out - ctx->zstr.avail_out;
226
227	99.0k	switch (ret) {
228	42.2k	case Z_OK:
229	42.2k	return ZIP_COMPRESSION_OK;
230
231	4.36k	case Z_STREAM_END:
232	4.36k	return ZIP_COMPRESSION_END;
233
234	42.3k	case Z_BUF_ERROR:
235	42.3k	if (ctx->zstr.avail_in == 0) {
236	42.3k	return ZIP_COMPRESSION_NEED_DATA;
237	42.3k	}
238
239		/* fallthrough */
240
241	10.0k	default:
242	10.0k	zip_error_set(ctx->error, ZIP_ER_ZLIB, ret);
243	10.0k	return ZIP_COMPRESSION_ERROR;
244	99.0k	}
245	99.0k	}
246
247		/* clang-format off */
248
249		zip_compression_algorithm_t zip_algorithm_deflate_compress = {
250		maximum_compressed_size,
251		compress_allocate,
252		deallocate,
253		general_purpose_bit_flags,
254		20,
255		start,
256		end,
257		input,
258		end_of_input,
259		process
260		};
261
262
263		zip_compression_algorithm_t zip_algorithm_deflate_decompress = {
264		maximum_compressed_size,
265		decompress_allocate,
266		deallocate,
267		general_purpose_bit_flags,
268		20,
269		start,
270		end,
271		input,
272		end_of_input,
273		process
274		};
275
276		/* clang-format on */