VeraCrypt
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Diffstat (limited to 'src/Common/libzip/zip_source_pkware.c')
-rw-r--r--src/Common/libzip/zip_source_pkware.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/src/Common/libzip/zip_source_pkware.c b/src/Common/libzip/zip_source_pkware.c
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+++ b/src/Common/libzip/zip_source_pkware.c
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+/*
+ zip_source_pkware.c -- Traditional PKWARE de/encryption routines
+ Copyright (C) 2009-2015 Dieter Baron and Thomas Klausner
+
+ This file is part of libzip, a library to manipulate ZIP archives.
+ The authors can be contacted at <libzip@nih.at>
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ 1. Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in
+ the documentation and/or other materials provided with the
+ distribution.
+ 3. The names of the authors may not be used to endorse or promote
+ products derived from this software without specific prior
+ written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
+ OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
+ DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "zipint.h"
+
+struct trad_pkware {
+ zip_error_t error;
+ zip_uint32_t key[3];
+};
+
+#define HEADERLEN 12
+#define KEY0 305419896
+#define KEY1 591751049
+#define KEY2 878082192
+
+
+static void decrypt(struct trad_pkware *, zip_uint8_t *,
+ const zip_uint8_t *, zip_uint64_t, int);
+static int decrypt_header(zip_source_t *, struct trad_pkware *);
+static zip_int64_t pkware_decrypt(zip_source_t *, void *, void *,
+ zip_uint64_t, zip_source_cmd_t);
+static void pkware_free(struct trad_pkware *);
+
+
+zip_source_t *
+zip_source_pkware(zip_t *za, zip_source_t *src,
+ zip_uint16_t em, int flags, const char *password)
+{
+ struct trad_pkware *ctx;
+ zip_source_t *s2;
+
+ if (password == NULL || src == NULL || em != ZIP_EM_TRAD_PKWARE) {
+ zip_error_set(&za->error, ZIP_ER_INVAL, 0);
+ return NULL;
+ }
+ if (flags & ZIP_CODEC_ENCODE) {
+ zip_error_set(&za->error, ZIP_ER_ENCRNOTSUPP, 0);
+ return NULL;
+ }
+
+ if ((ctx=(struct trad_pkware *)malloc(sizeof(*ctx))) == NULL) {
+ zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
+ return NULL;
+ }
+
+ zip_error_init(&ctx->error);
+
+ ctx->key[0] = KEY0;
+ ctx->key[1] = KEY1;
+ ctx->key[2] = KEY2;
+ decrypt(ctx, NULL, (const zip_uint8_t *)password, strlen(password), 1);
+
+ if ((s2=zip_source_layered(za, src, pkware_decrypt, ctx)) == NULL) {
+ pkware_free(ctx);
+ return NULL;
+ }
+
+ return s2;
+}
+
+
+static void
+decrypt(struct trad_pkware *ctx, zip_uint8_t *out, const zip_uint8_t *in,
+ zip_uint64_t len, int update_only)
+{
+ zip_uint16_t tmp;
+ zip_uint64_t i;
+ Bytef b;
+
+ for (i=0; i<len; i++) {
+ b = in[i];
+
+ if (!update_only) {
+ /* decrypt next byte */
+ tmp = (zip_uint16_t)(ctx->key[2] | 2);
+ tmp = (zip_uint16_t)(((zip_uint32_t)tmp * (tmp ^ 1)) >> 8);
+ b ^= (Bytef)tmp;
+ }
+
+ /* store cleartext */
+ if (out)
+ out[i] = b;
+
+ /* update keys */
+ ctx->key[0] = (zip_uint32_t)crc32(ctx->key[0] ^ 0xffffffffUL, &b, 1) ^ 0xffffffffUL;
+ ctx->key[1] = (ctx->key[1] + (ctx->key[0] & 0xff)) * 134775813 + 1;
+ b = (Bytef)(ctx->key[1] >> 24);
+ ctx->key[2] = (zip_uint32_t)crc32(ctx->key[2] ^ 0xffffffffUL, &b, 1) ^ 0xffffffffUL;
+ }
+}
+
+
+static int
+decrypt_header(zip_source_t *src, struct trad_pkware *ctx)
+{
+ zip_uint8_t header[HEADERLEN];
+ struct zip_stat st;
+ zip_int64_t n;
+ unsigned short dostime, dosdate;
+
+ if ((n=zip_source_read(src, header, HEADERLEN)) < 0) {
+ _zip_error_set_from_source(&ctx->error, src);
+ return -1;
+ }
+
+ if (n != HEADERLEN) {
+ zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
+ return -1;
+ }
+
+ decrypt(ctx, header, header, HEADERLEN, 0);
+
+ if (zip_source_stat(src, &st) < 0) {
+ /* stat failed, skip password validation */
+ return 0;
+ }
+
+ _zip_u2d_time(st.mtime, &dostime, &dosdate);
+
+ if (header[HEADERLEN-1] != st.crc>>24 && header[HEADERLEN-1] != dostime>>8) {
+ zip_error_set(&ctx->error, ZIP_ER_WRONGPASSWD, 0);
+ return -1;
+ }
+
+ return 0;
+}
+
+
+static zip_int64_t
+pkware_decrypt(zip_source_t *src, void *ud, void *data,
+ zip_uint64_t len, zip_source_cmd_t cmd)
+{
+ struct trad_pkware *ctx;
+ zip_int64_t n;
+
+ ctx = (struct trad_pkware *)ud;
+
+ switch (cmd) {
+ case ZIP_SOURCE_OPEN:
+ if (decrypt_header(src, ctx) < 0)
+ return -1;
+ return 0;
+
+ case ZIP_SOURCE_READ:
+ if ((n=zip_source_read(src, data, len)) < 0) {
+ _zip_error_set_from_source(&ctx->error, src);
+ return -1;
+ }
+
+ decrypt((struct trad_pkware *)ud, (zip_uint8_t *)data, (zip_uint8_t *)data, (zip_uint64_t)n, 0);
+ return n;
+
+ case ZIP_SOURCE_CLOSE:
+ return 0;
+
+ case ZIP_SOURCE_STAT:
+ {
+ zip_stat_t *st;
+
+ st = (zip_stat_t *)data;
+
+ st->encryption_method = ZIP_EM_NONE;
+ st->valid |= ZIP_STAT_ENCRYPTION_METHOD;
+ /* TODO: deduce HEADERLEN from size for uncompressed */
+ if (st->valid & ZIP_STAT_COMP_SIZE)
+ st->comp_size -= HEADERLEN;
+
+ return 0;
+ }
+
+ case ZIP_SOURCE_SUPPORTS:
+ 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);
+
+ case ZIP_SOURCE_ERROR:
+ return zip_error_to_data(&ctx->error, data, len);
+
+ case ZIP_SOURCE_FREE:
+ pkware_free(ctx);
+ return 0;
+
+ default:
+ zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
+ return -1;
+ }
+}
+
+
+static void
+pkware_free(struct trad_pkware *ctx)
+{
+ free(ctx);
+}