1 /*
2 zip_source_zip_new.c -- prepare data structures for zip_fopen/zip_source_zip
3 Copyright (C) 2012-2015 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 <libzip@nih.at>
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
35 #include <stdlib.h>
36
37 #include "zipint.h"
38
39
40 zip_source_t *
_zip_source_zip_new(zip_t * za,zip_t * srcza,zip_uint64_t srcidx,zip_flags_t flags,zip_uint64_t start,zip_uint64_t len,const char * password)41 _zip_source_zip_new(zip_t *za, zip_t *srcza, zip_uint64_t srcidx, zip_flags_t flags, zip_uint64_t start, zip_uint64_t len, const char *password)
42 {
43 zip_compression_implementation comp_impl;
44 zip_encryption_implementation enc_impl;
45 zip_source_t *src, *s2;
46 zip_uint64_t offset;
47 struct zip_stat st;
48
49 if (za == NULL)
50 return NULL;
51
52 if (srcza == NULL || srcidx >= srcza->nentry) {
53 zip_error_set(&za->error, ZIP_ER_INVAL, 0);
54 return NULL;
55 }
56
57 if ((flags & ZIP_FL_UNCHANGED) == 0
58 && (ZIP_ENTRY_DATA_CHANGED(srcza->entry+srcidx) || srcza->entry[srcidx].deleted)) {
59 zip_error_set(&za->error, ZIP_ER_CHANGED, 0);
60 return NULL;
61 }
62
63 if (zip_stat_index(srcza, srcidx, flags|ZIP_FL_UNCHANGED, &st) < 0) {
64 zip_error_set(&za->error, ZIP_ER_INTERNAL, 0);
65 return NULL;
66 }
67
68 if (flags & ZIP_FL_ENCRYPTED)
69 flags |= ZIP_FL_COMPRESSED;
70
71 if ((start > 0 || len > 0) && (flags & ZIP_FL_COMPRESSED)) {
72 zip_error_set(&za->error, ZIP_ER_INVAL, 0);
73 return NULL;
74 }
75
76 /* overflow or past end of file */
77 if ((start > 0 || len > 0) && (start+len < start || start+len > st.size)) {
78 zip_error_set(&za->error, ZIP_ER_INVAL, 0);
79 return NULL;
80 }
81
82 enc_impl = NULL;
83 if (((flags & ZIP_FL_ENCRYPTED) == 0) && (st.encryption_method != ZIP_EM_NONE)) {
84 if (password == NULL) {
85 zip_error_set(&za->error, ZIP_ER_NOPASSWD, 0);
86 return NULL;
87 }
88 if ((enc_impl=_zip_get_encryption_implementation(st.encryption_method)) == NULL) {
89 zip_error_set(&za->error, ZIP_ER_ENCRNOTSUPP, 0);
90 return NULL;
91 }
92 }
93
94 comp_impl = NULL;
95 if ((flags & ZIP_FL_COMPRESSED) == 0) {
96 if (st.comp_method != ZIP_CM_STORE) {
97 if ((comp_impl=_zip_get_compression_implementation(st.comp_method)) == NULL) {
98 zip_error_set(&za->error, ZIP_ER_COMPNOTSUPP, 0);
99 return NULL;
100 }
101 }
102 }
103
104 if ((offset=_zip_file_get_offset(srcza, srcidx, &za->error)) == 0)
105 return NULL;
106
107 if (st.comp_size == 0) {
108 return zip_source_buffer(za, NULL, 0, 0);
109 }
110
111 if (start+len > 0 && enc_impl == NULL && comp_impl == NULL) {
112 struct zip_stat st2;
113
114 st2.size = len ? len : st.size-start;
115 st2.comp_size = st2.size;
116 st2.comp_method = ZIP_CM_STORE;
117 st2.mtime = st.mtime;
118 st2.valid = ZIP_STAT_SIZE|ZIP_STAT_COMP_SIZE|ZIP_STAT_COMP_METHOD|ZIP_STAT_MTIME;
119
120 if ((src = _zip_source_window_new(srcza->src, offset+start, st2.size, &st2, &za->error)) == NULL) {
121 return NULL;
122 }
123 }
124 else {
125 if ((src = _zip_source_window_new(srcza->src, offset, st.comp_size, &st, &za->error)) == NULL) {
126 return NULL;
127 }
128 }
129
130 if (_zip_source_set_source_archive(src, srcza) < 0) {
131 zip_source_free(src);
132 return NULL;
133 }
134
135 /* creating a layered source calls zip_keep() on the lower layer, so we free it */
136
137 if (enc_impl) {
138 s2 = enc_impl(za, src, st.encryption_method, 0, password);
139 zip_source_free(src);
140 if (s2 == NULL) {
141 return NULL;
142 }
143 src = s2;
144 }
145 if (comp_impl) {
146 s2 = comp_impl(za, src, st.comp_method, 0);
147 zip_source_free(src);
148 if (s2 == NULL) {
149 return NULL;
150 }
151 src = s2;
152 }
153 if (((flags & ZIP_FL_COMPRESSED) == 0 || st.comp_method == ZIP_CM_STORE) && (len == 0 || len == st.comp_size)) {
154 /* when reading the whole file, check for CRC errors */
155 s2 = zip_source_crc(za, src, 1);
156 zip_source_free(src);
157 if (s2 == NULL) {
158 return NULL;
159 }
160 src = s2;
161 }
162
163 if (start+len > 0 && (comp_impl || enc_impl)) {
164 s2 = zip_source_window(za, src, start, len ? len : st.size-start);
165 zip_source_free(src);
166 if (s2 == NULL) {
167 return NULL;
168 }
169 src = s2;
170 }
171
172 return src;
173 }
174
