1 /*
2 zip_source_zip_new.c -- prepare data structures for zip_fopen/zip_source_zip
3 Copyright (C) 2012 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
36 #include <stdlib.h>
37
38 #include "zipint.h"
39
40
41
42 struct zip_source *
_zip_source_zip_new(struct zip * za,struct zip * srcza,zip_uint64_t srcidx,zip_flags_t flags,zip_uint64_t start,zip_uint64_t len,const char * password)43 _zip_source_zip_new(struct zip *za, struct zip *srcza, zip_uint64_t srcidx, zip_flags_t flags,
44 zip_uint64_t start, zip_uint64_t len, const char *password)
45 {
46 zip_compression_implementation comp_impl;
47 zip_encryption_implementation enc_impl;
48 struct zip_source *src, *s2;
49 zip_uint64_t offset;
50 struct zip_stat st;
51
52 if (za == NULL)
53 return NULL;
54
55 if (srcza == NULL || srcidx >= srcza->nentry) {
56 _zip_error_set(&za->error, ZIP_ER_INVAL, 0);
57 return NULL;
58 }
59
60 if ((flags & ZIP_FL_UNCHANGED) == 0
61 && (ZIP_ENTRY_DATA_CHANGED(srcza->entry+srcidx) || srcza->entry[srcidx].deleted)) {
62 _zip_error_set(&za->error, ZIP_ER_CHANGED, 0);
63 return NULL;
64 }
65
66 if (zip_stat_index(srcza, srcidx, flags|ZIP_FL_UNCHANGED, &st) < 0) {
67 _zip_error_set(&za->error, ZIP_ER_INTERNAL, 0);
68 return NULL;
69 }
70
71 if (flags & ZIP_FL_ENCRYPTED)
72 flags |= ZIP_FL_COMPRESSED;
73
74 if ((start > 0 || len > 0) && (flags & ZIP_FL_COMPRESSED)) {
75 _zip_error_set(&za->error, ZIP_ER_INVAL, 0);
76 return NULL;
77 }
78
79 /* overflow or past end of file */
80 if ((start > 0 || len > 0) && (start+len < start || start+len > st.size)) {
81 _zip_error_set(&za->error, ZIP_ER_INVAL, 0);
82 return NULL;
83 }
84
85 enc_impl = NULL;
86 if (((flags & ZIP_FL_ENCRYPTED) == 0) && (st.encryption_method != ZIP_EM_NONE)) {
87 if (password == NULL) {
88 _zip_error_set(&za->error, ZIP_ER_NOPASSWD, 0);
89 return NULL;
90 }
91 if ((enc_impl=_zip_get_encryption_implementation(st.encryption_method)) == NULL) {
92 _zip_error_set(&za->error, ZIP_ER_ENCRNOTSUPP, 0);
93 return NULL;
94 }
95 }
96
97 comp_impl = NULL;
98 if ((flags & ZIP_FL_COMPRESSED) == 0) {
99 if (st.comp_method != ZIP_CM_STORE) {
100 if ((comp_impl=_zip_get_compression_implementation(st.comp_method)) == NULL) {
101 _zip_error_set(&za->error, ZIP_ER_COMPNOTSUPP, 0);
102 return NULL;
103 }
104 }
105 }
106
107 if ((offset=_zip_file_get_offset(srcza, srcidx, &za->error)) == 0)
108 return NULL;
109
110 if (st.comp_size == 0) {
111 if ((src=zip_source_buffer(za, NULL, 0, 0)) == NULL)
112 return NULL;
113 }
114 else {
115 if (start+len > 0 && enc_impl == NULL && comp_impl == NULL) {
116 struct zip_stat st2;
117
118 st2.size = len ? len : st.size-start;
119 st2.comp_size = st2.size;
120 st2.comp_method = ZIP_CM_STORE;
121 st2.mtime = st.mtime;
122 st2.valid = ZIP_STAT_SIZE|ZIP_STAT_COMP_SIZE|ZIP_STAT_COMP_METHOD|ZIP_STAT_MTIME;
123
124 /* TODO: check for overflow of st2.size */
125 if ((src=_zip_source_file_or_p(za, NULL, srcza->zp, offset+start, (zip_int64_t)st2.size, 0, &st2)) == NULL)
126 return NULL;
127 }
128 else {
129 /* TODO: check for overflow of st.comp_size */
130 if ((src=_zip_source_file_or_p(za, NULL, srcza->zp, offset, (zip_int64_t)st.comp_size, 0, &st)) == NULL)
131 return NULL;
132 }
133
134 if (enc_impl) {
135 if ((s2=enc_impl(za, src, st.encryption_method, 0, password)) == NULL) {
136 zip_source_free(src);
137 /* TODO: set error (how?) */
138 return NULL;
139 }
140 src = s2;
141 }
142 if (comp_impl) {
143 if ((s2=comp_impl(za, src, st.comp_method, 0)) == NULL) {
144 zip_source_free(src);
145 /* TODO: set error (how?) */
146 return NULL;
147 }
148 src = s2;
149 }
150 if (((flags & ZIP_FL_COMPRESSED) == 0 || st.comp_method == ZIP_CM_STORE)
151 && (len == 0 || len == st.comp_size)) {
152 /* when reading the whole file, check for crc errors */
153 if ((s2=zip_source_crc(za, src, 1)) == NULL) {
154 zip_source_free(src);
155 /* TODO: set error (how?) */
156 return NULL;
157 }
158 src = s2;
159 }
160
161 if (start+len > 0 && (comp_impl || enc_impl)) {
162 if ((s2=zip_source_window(za, src, start, len ? len : st.size-start)) == NULL) {
163 zip_source_free(src);
164 /* TODO: set error (how?) (why?) */
165 return NULL;
166 }
167 src = s2;
168 }
169 }
170
171 return src;
172 }
173
