2 zip_source_pkware.c -- Traditional PKWARE de/encryption routines
3 Copyright (C) 2009-2016 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.
46 #define KEY0 305419896
47 #define KEY1 591751049
48 #define KEY2 878082192
51 static void decrypt(struct trad_pkware *, zip_uint8_t *,
52 const zip_uint8_t *, zip_uint64_t, int);
53 static int decrypt_header(zip_source_t *, struct trad_pkware *);
54 static zip_int64_t pkware_decrypt(zip_source_t *, void *, void *,
55 zip_uint64_t, zip_source_cmd_t);
56 static void pkware_free(struct trad_pkware *);
60 zip_source_pkware(zip_t *za, zip_source_t *src,
61 zip_uint16_t em, int flags, const char *password)
63 struct trad_pkware *ctx;
66 if (password == NULL || src == NULL || em != ZIP_EM_TRAD_PKWARE) {
67 zip_error_set(&za->error, ZIP_ER_INVAL, 0);
70 if (flags & ZIP_CODEC_ENCODE) {
71 zip_error_set(&za->error, ZIP_ER_ENCRNOTSUPP, 0);
75 if ((ctx=(struct trad_pkware *)malloc(sizeof(*ctx))) == NULL) {
76 zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
80 zip_error_init(&ctx->error);
85 decrypt(ctx, NULL, (const zip_uint8_t *)password, strlen(password), 1);
87 if ((s2=zip_source_layered(za, src, pkware_decrypt, ctx)) == NULL) {
97 decrypt(struct trad_pkware *ctx, zip_uint8_t *out, const zip_uint8_t *in,
98 zip_uint64_t len, int update_only)
104 for (i=0; i<len; i++) {
108 /* decrypt next byte */
109 tmp = (zip_uint16_t)(ctx->key[2] | 2);
110 tmp = (zip_uint16_t)(((zip_uint32_t)tmp * (tmp ^ 1)) >> 8);
114 /* store cleartext */
119 ctx->key[0] = (zip_uint32_t)crc32(ctx->key[0] ^ 0xffffffffUL, &b, 1) ^ 0xffffffffUL;
120 ctx->key[1] = (ctx->key[1] + (ctx->key[0] & 0xff)) * 134775813 + 1;
121 b = (Bytef)(ctx->key[1] >> 24);
122 ctx->key[2] = (zip_uint32_t)crc32(ctx->key[2] ^ 0xffffffffUL, &b, 1) ^ 0xffffffffUL;
128 decrypt_header(zip_source_t *src, struct trad_pkware *ctx)
130 zip_uint8_t header[HEADERLEN];
133 unsigned short dostime, dosdate;
135 if ((n=zip_source_read(src, header, HEADERLEN)) < 0) {
136 _zip_error_set_from_source(&ctx->error, src);
140 if (n != HEADERLEN) {
141 zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
145 decrypt(ctx, header, header, HEADERLEN, 0);
147 if (zip_source_stat(src, &st) < 0) {
148 /* stat failed, skip password validation */
152 _zip_u2d_time(st.mtime, &dostime, &dosdate);
154 if (header[HEADERLEN-1] != st.crc>>24 && header[HEADERLEN-1] != dostime>>8) {
155 zip_error_set(&ctx->error, ZIP_ER_WRONGPASSWD, 0);
164 pkware_decrypt(zip_source_t *src, void *ud, void *data,
165 zip_uint64_t len, zip_source_cmd_t cmd)
167 struct trad_pkware *ctx;
170 ctx = (struct trad_pkware *)ud;
173 case ZIP_SOURCE_OPEN:
174 if (decrypt_header(src, ctx) < 0)
178 case ZIP_SOURCE_READ:
179 if ((n=zip_source_read(src, data, len)) < 0) {
180 _zip_error_set_from_source(&ctx->error, src);
184 decrypt((struct trad_pkware *)ud, (zip_uint8_t *)data, (zip_uint8_t *)data, (zip_uint64_t)n, 0);
187 case ZIP_SOURCE_CLOSE:
190 case ZIP_SOURCE_STAT:
194 st = (zip_stat_t *)data;
196 st->encryption_method = ZIP_EM_NONE;
197 st->valid |= ZIP_STAT_ENCRYPTION_METHOD;
198 /* TODO: deduce HEADERLEN from size for uncompressed */
199 if (st->valid & ZIP_STAT_COMP_SIZE)
200 st->comp_size -= HEADERLEN;
205 case ZIP_SOURCE_SUPPORTS:
206 return zip_source_make_command_bitmap(ZIP_SOURCE_OPEN, ZIP_SOURCE_READ, ZIP_SOURCE_CLOSE, ZIP_SOURCE_STAT, ZIP_SOURCE_ERROR, ZIP_SOURCE_FREE, -1);
208 case ZIP_SOURCE_ERROR:
209 return zip_error_to_data(&ctx->error, data, len);
211 case ZIP_SOURCE_FREE:
216 zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
223 pkware_free(struct trad_pkware *ctx)