VeraCrypt
aboutsummaryrefslogtreecommitdiff
path: root/src/Common/libzip/zip_source_window.c
blob: f4701a04b2ca599d1bc7f1ac040d80a53c64fdb4 (plain)
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
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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
/*
  zip_source_window.c -- return part of lower source
  Copyright (C) 2012-2017 Dieter Baron and Thomas Klausner

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

  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 <stdlib.h>
#include <string.h>

#include "zipint.h"

struct window {
    zip_uint64_t start; /* where in file we start reading */
    zip_uint64_t end;   /* where in file we stop reading */

    /* if not NULL, read file data for this file */
    zip_t *source_archive;
    zip_uint64_t source_index;

    zip_uint64_t offset; /* offset in src for next read */

    zip_stat_t stat;
    zip_int8_t compression_flags;
    zip_error_t error;
    zip_int64_t supports;
    bool needs_seek;
};

static zip_int64_t window_read(zip_source_t *, void *, void *, zip_uint64_t, zip_source_cmd_t);


zip_source_t *
zip_source_window(zip_t *za, zip_source_t *src, zip_uint64_t start, zip_uint64_t len) {
    return _zip_source_window_new(src, start, len, NULL, 0, NULL, 0, &za->error);
}


zip_source_t *
_zip_source_window_new(zip_source_t *src, zip_uint64_t start, zip_uint64_t length, zip_stat_t *st, zip_int8_t compression_flags, zip_t *source_archive, zip_uint64_t source_index, zip_error_t *error) {
    struct window *ctx;

    if (src == NULL || start + length < start || (source_archive == NULL && source_index != 0)) {
	zip_error_set(error, ZIP_ER_INVAL, 0);
	return NULL;
    }

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

    ctx->start = start;
    ctx->end = start + length;
    zip_stat_init(&ctx->stat);
    ctx->compression_flags = compression_flags;
    ctx->source_archive = source_archive;
    ctx->source_index = source_index;
    zip_error_init(&ctx->error);
    ctx->supports = (zip_source_supports(src) & ZIP_SOURCE_SUPPORTS_SEEKABLE) | (zip_source_make_command_bitmap(ZIP_SOURCE_GET_COMPRESSION_FLAGS, ZIP_SOURCE_SUPPORTS, ZIP_SOURCE_TELL, -1));
    ctx->needs_seek = (ctx->supports & ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_SEEK)) ? true : false;

    if (st) {
	if (_zip_stat_merge(&ctx->stat, st, error) < 0) {
	    free(ctx);
	    return NULL;
	}
    }

    return zip_source_layered_create(src, window_read, ctx, error);
}


int
_zip_source_set_source_archive(zip_source_t *src, zip_t *za) {
    src->source_archive = za;
    return _zip_register_source(za, src);
}


/* called by zip_discard to avoid operating on file from closed archive */
void
_zip_source_invalidate(zip_source_t *src) {
    src->source_closed = 1;

    if (zip_error_code_zip(&src->error) == ZIP_ER_OK) {
	zip_error_set(&src->error, ZIP_ER_ZIPCLOSED, 0);
    }
}


static zip_int64_t
window_read(zip_source_t *src, void *_ctx, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
    struct window *ctx;
    zip_int64_t ret;
    zip_uint64_t n, i;
    char b[8192];

    ctx = (struct window *)_ctx;

    switch (cmd) {
    case ZIP_SOURCE_CLOSE:
	return 0;

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

    case ZIP_SOURCE_FREE:
	free(ctx);
	return 0;

    case ZIP_SOURCE_OPEN:
	if (ctx->source_archive) {
	    zip_uint64_t offset;

	    if ((offset = _zip_file_get_offset(ctx->source_archive, ctx->source_index, &ctx->error)) == 0) {
		return -1;
	    }
	    if (ctx->end + offset < ctx->end) {
		/* zip archive data claims end of data past zip64 limits */
		zip_error_set(&ctx->error, ZIP_ER_INCONS, 0);
		return -1;
	    }
	    ctx->start += offset;
	    ctx->end += offset;
	    ctx->source_archive = NULL;
	}

	if (!ctx->needs_seek) {
	    for (n = 0; n < ctx->start; n += (zip_uint64_t)ret) {
		i = (ctx->start - n > sizeof(b) ? sizeof(b) : ctx->start - n);
		if ((ret = zip_source_read(src, b, i)) < 0) {
		    _zip_error_set_from_source(&ctx->error, src);
		    return -1;
		}
		if (ret == 0) {
		    zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
		    return -1;
		}
	    }
	}
	ctx->offset = ctx->start;
	return 0;

    case ZIP_SOURCE_READ:
	if (len > ctx->end - ctx->offset)
	    len = ctx->end - ctx->offset;

	if (len == 0)
	    return 0;

	if (ctx->needs_seek) {
	    if (zip_source_seek(src, (zip_int64_t)ctx->offset, SEEK_SET) < 0) {
		_zip_error_set_from_source(&ctx->error, src);
		return -1;
	    }
	}

	if ((ret = zip_source_read(src, data, len)) < 0) {
	    zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
	    return -1;
	}

	ctx->offset += (zip_uint64_t)ret;

	if (ret == 0) {
	    if (ctx->offset < ctx->end) {
		zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
		return -1;
	    }
	}
	return ret;

    case ZIP_SOURCE_SEEK: {
	zip_int64_t new_offset = zip_source_seek_compute_offset(ctx->offset - ctx->start, ctx->end - ctx->start, data, len, &ctx->error);

	if (new_offset < 0) {
	    return -1;
	}

	ctx->offset = (zip_uint64_t)new_offset + ctx->start;
	return 0;
    }

    case ZIP_SOURCE_STAT: {
	zip_stat_t *st;

	st = (zip_stat_t *)data;

	if (_zip_stat_merge(st, &ctx->stat, &ctx->error) < 0) {
	    return -1;
	}
	return 0;
    }

    case ZIP_SOURCE_GET_COMPRESSION_FLAGS:
	return ctx->compression_flags;

    case ZIP_SOURCE_SUPPORTS:
	return ctx->supports;

    case ZIP_SOURCE_TELL:
	return (zip_int64_t)(ctx->offset - ctx->start);

    default:
	zip_error_set(&ctx->error, ZIP_ER_OPNOTSUPP, 0);
	return -1;
    }
}


void
_zip_deregister_source(zip_t *za, zip_source_t *src) {
    unsigned int i;

    for (i = 0; i < za->nopen_source; i++) {
	if (za->open_source[i] == src) {
	    za->open_source[i] = za->open_source[za->nopen_source - 1];
	    za->nopen_source--;
	    break;
	}
    }
}


int
_zip_register_source(zip_t *za, zip_source_t *src) {
    zip_source_t **open_source;

    if (za->nopen_source + 1 >= za->nopen_source_alloc) {
	unsigned int n;
	n = za->nopen_source_alloc + 10;
	open_source = (zip_source_t **)realloc(za->open_source, n * sizeof(zip_source_t *));
	if (open_source == NULL) {
	    zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
	    return -1;
	}
	za->nopen_source_alloc = n;
	za->open_source = open_source;
    }

    za->open_source[za->nopen_source++] = src;

    return 0;
}