xref: /PHP-5.3/ext/zip/lib/zip_source_crc.c (revision 335a11b1)
1 /*
2   zip_source_crc.c -- pass-through source that calculates CRC32 and size
3   Copyright (C) 2009 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 #include <string.h>
38 
39 #include "zipint.h"
40 
41 struct crc {
42     int eof;
43     int validate;
44     int e[2];
45     zip_uint64_t size;
46     zip_uint32_t crc;
47 };
48 
49 static zip_int64_t crc_read(struct zip_source *, void *, void *
50 			    , zip_uint64_t, enum zip_source_cmd);
51 
52 
53 
54 ZIP_EXTERN(struct zip_source *)
zip_source_crc(struct zip * za,struct zip_source * src,int validate)55 zip_source_crc(struct zip *za, struct zip_source *src, int validate)
56 {
57     struct crc *ctx;
58 
59     if (src == NULL) {
60 	_zip_error_set(&za->error, ZIP_ER_INVAL, 0);
61 	return NULL;
62     }
63 
64     if ((ctx=(struct crc *)malloc(sizeof(*ctx))) == NULL) {
65 	_zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
66 	return NULL;
67     }
68 
69     ctx->validate = validate;
70 
71     return zip_source_layered(za, src, crc_read, ctx);
72 }
73 
74 
75 
76 static zip_int64_t
crc_read(struct zip_source * src,void * _ctx,void * data,zip_uint64_t len,enum zip_source_cmd cmd)77 crc_read(struct zip_source *src, void *_ctx, void *data,
78 	 zip_uint64_t len, enum zip_source_cmd cmd)
79 {
80     struct crc *ctx;
81     zip_int64_t n;
82 
83     ctx = (struct crc *)_ctx;
84 
85     switch (cmd) {
86     case ZIP_SOURCE_OPEN:
87 	ctx->eof = 0;
88 	ctx->crc = crc32(0, NULL, 0);
89 	ctx->size = 0;
90 
91 	return 0;
92 
93     case ZIP_SOURCE_READ:
94 	if (ctx->eof || len == 0)
95 	    return 0;
96 
97 	if ((n=zip_source_read(src, data, len)) < 0)
98 	    return ZIP_SOURCE_ERR_LOWER;
99 
100 	if (n == 0) {
101 	    ctx->eof = 1;
102 	    if (ctx->validate) {
103 		struct zip_stat st;
104 
105 		if (zip_source_stat(src, &st) < 0)
106 		    return ZIP_SOURCE_ERR_LOWER;
107 
108 		if ((st.valid & ZIP_STAT_CRC) && st.crc != ctx->crc) {
109 		    ctx->e[0] = ZIP_ER_CRC;
110 		    ctx->e[1] = 0;
111 
112 		    return -1;
113 		}
114 		if ((st.valid & ZIP_STAT_SIZE) && st.size != ctx->size) {
115 		    ctx->e[0] = ZIP_ER_INCONS;
116 		    ctx->e[1] = 0;
117 
118 		    return -1;
119 		}
120 	    }
121 	}
122 	else {
123 	    ctx->size += n;
124 	    ctx->crc = crc32(ctx->crc, data, n);
125 	}
126 	return n;
127 
128     case ZIP_SOURCE_CLOSE:
129 	return 0;
130 
131     case ZIP_SOURCE_STAT:
132 	{
133 	    struct zip_stat *st;
134 
135 	    st = (struct zip_stat *)data;
136 
137 	    if (ctx->eof) {
138 		/* XXX: Set comp_size, comp_method, encryption_method?
139 		        After all, this only works for uncompressed data. */
140 		st->size = ctx->size;
141 		st->crc = ctx->crc;
142 		st->valid |= ZIP_STAT_SIZE|ZIP_STAT_CRC;
143 	    }
144 	}
145 	return 0;
146 
147     case ZIP_SOURCE_ERROR:
148 	memcpy(data, ctx->e, sizeof(ctx->e));
149 	return 0;
150 
151     case ZIP_SOURCE_FREE:
152 	free(ctx);
153 	return 0;
154 
155     default:
156 	return -1;
157     }
158 
159 }
160