2 zip_source_crc.c -- pass-through source that calculates CRC32 and size
3 Copyright (C) 2009-2019 Dieter Baron and Thomas Klausner
5 This file is part of libzip, a library to manipulate ZIP archives.
6 The authors can be contacted at <libzip@nih.at>
8 Redistribution and use in source and binary forms, with or without
9 modification, are permitted provided that the following conditions
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
17 3. The names of the authors may not be used to endorse or promote
18 products derived from this software without specific prior
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.
42 int validate; /* whether to check CRC on EOF and return error on mismatch */
43 int crc_complete; /* whether CRC was computed for complete file */
46 zip_uint64_t position; /* current reading position */
47 zip_uint64_t crc_position; /* how far we've computed the CRC */
51 static zip_int64_t crc_read(zip_source_t *, void *, void *, zip_uint64_t, zip_source_cmd_t);
55 zip_source_crc(zip_t *za, zip_source_t *src, int validate) {
56 struct crc_context *ctx;
59 zip_error_set(&za->error, ZIP_ER_INVAL, 0);
63 if ((ctx = (struct crc_context *)malloc(sizeof(*ctx))) == NULL) {
64 zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
68 zip_error_init(&ctx->error);
69 ctx->validate = validate;
70 ctx->crc_complete = 0;
71 ctx->crc_position = 0;
72 ctx->crc = (zip_uint32_t)crc32(0, NULL, 0);
75 return zip_source_layered(za, src, crc_read, ctx);
80 crc_read(zip_source_t *src, void *_ctx, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
81 struct crc_context *ctx;
84 ctx = (struct crc_context *)_ctx;
92 if ((n = zip_source_read(src, data, len)) < 0) {
93 _zip_error_set_from_source(&ctx->error, src);
98 if (ctx->crc_position == ctx->position) {
99 ctx->crc_complete = 1;
100 ctx->size = ctx->position;
105 if (zip_source_stat(src, &st) < 0) {
106 _zip_error_set_from_source(&ctx->error, src);
110 if ((st.valid & ZIP_STAT_CRC) && st.crc != ctx->crc) {
111 zip_error_set(&ctx->error, ZIP_ER_CRC, 0);
114 if ((st.valid & ZIP_STAT_SIZE) && st.size != ctx->size) {
115 zip_error_set(&ctx->error, ZIP_ER_INCONS, 0);
121 else if (!ctx->crc_complete && ctx->position <= ctx->crc_position) {
124 for (i = ctx->crc_position - ctx->position; i < (zip_uint64_t)n; i += nn) {
125 nn = ZIP_MIN(UINT_MAX, (zip_uint64_t)n - i);
127 ctx->crc = (zip_uint32_t)crc32(ctx->crc, (const Bytef *)data + i, (uInt)nn);
128 ctx->crc_position += nn;
131 ctx->position += (zip_uint64_t)n;
134 case ZIP_SOURCE_CLOSE:
137 case ZIP_SOURCE_STAT: {
140 st = (zip_stat_t *)data;
142 if (ctx->crc_complete) {
143 /* TODO: Set comp_size, comp_method, encryption_method?
144 After all, this only works for uncompressed data. */
145 st->size = ctx->size;
147 st->comp_size = ctx->size;
148 st->comp_method = ZIP_CM_STORE;
149 st->encryption_method = ZIP_EM_NONE;
150 st->valid |= ZIP_STAT_SIZE | ZIP_STAT_CRC | ZIP_STAT_COMP_SIZE | ZIP_STAT_COMP_METHOD | ZIP_STAT_ENCRYPTION_METHOD;
155 case ZIP_SOURCE_ERROR:
156 return zip_error_to_data(&ctx->error, data, len);
158 case ZIP_SOURCE_FREE:
162 case ZIP_SOURCE_SUPPORTS: {
163 zip_int64_t mask = zip_source_supports(src);
166 _zip_error_set_from_source(&ctx->error, src);
170 return mask & ~zip_source_make_command_bitmap(ZIP_SOURCE_BEGIN_WRITE, ZIP_SOURCE_COMMIT_WRITE, ZIP_SOURCE_ROLLBACK_WRITE, ZIP_SOURCE_SEEK_WRITE, ZIP_SOURCE_TELL_WRITE, ZIP_SOURCE_REMOVE, ZIP_SOURCE_GET_FILE_ATTRIBUTES, -1);
173 case ZIP_SOURCE_SEEK: {
174 zip_int64_t new_position;
175 zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, len, &ctx->error);
180 if (zip_source_seek(src, args->offset, args->whence) < 0 || (new_position = zip_source_tell(src)) < 0) {
181 _zip_error_set_from_source(&ctx->error, src);
185 ctx->position = (zip_uint64_t)new_position;
190 case ZIP_SOURCE_TELL:
191 return (zip_int64_t)ctx->position;
194 zip_error_set(&ctx->error, ZIP_ER_OPNOTSUPP, 0);