VeraCrypt
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path: root/src/Common/libzip/zip_source_pkware_decode.c
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-rw-r--r--src/Common/libzip/zip_source_pkware_decode.c222
1 files changed, 222 insertions, 0 deletions
diff --git a/src/Common/libzip/zip_source_pkware_decode.c b/src/Common/libzip/zip_source_pkware_decode.c
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+++ b/src/Common/libzip/zip_source_pkware_decode.c
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+/*
+ zip_source_pkware_decode.c -- Traditional PKWARE decryption routines
+ Copyright (C) 2009-2020 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 {
+ char *password;
+ zip_pkware_keys_t keys;
+ zip_error_t error;
+};
+
+
+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 struct trad_pkware *trad_pkware_new(const char *password, zip_error_t *error);
+static void trad_pkware_free(struct trad_pkware *);
+
+
+zip_source_t *
+zip_source_pkware_decode(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 = trad_pkware_new(password, &za->error)) == NULL) {
+ return NULL;
+ }
+
+ if ((s2 = zip_source_layered(za, src, pkware_decrypt, ctx)) == NULL) {
+ trad_pkware_free(ctx);
+ return NULL;
+ }
+
+ return s2;
+}
+
+
+static int
+decrypt_header(zip_source_t *src, struct trad_pkware *ctx) {
+ zip_uint8_t header[ZIP_CRYPTO_PKWARE_HEADERLEN];
+ struct zip_stat st;
+ zip_int64_t n;
+ bool ok;
+
+ if ((n = zip_source_read(src, header, ZIP_CRYPTO_PKWARE_HEADERLEN)) < 0) {
+ _zip_error_set_from_source(&ctx->error, src);
+ return -1;
+ }
+
+ if (n != ZIP_CRYPTO_PKWARE_HEADERLEN) {
+ zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
+ return -1;
+ }
+
+ _zip_pkware_decrypt(&ctx->keys, header, header, ZIP_CRYPTO_PKWARE_HEADERLEN);
+
+ if (zip_source_stat(src, &st)) {
+ /* stat failed, skip password validation */
+ return 0;
+ }
+
+ /* password verification - two ways:
+ * mtime - InfoZIP way, to avoid computing complete CRC before encrypting data
+ * CRC - old PKWare way
+ */
+
+ ok = false;
+
+ if (st.valid & ZIP_STAT_MTIME) {
+ unsigned short dostime, dosdate;
+ _zip_u2d_time(st.mtime, &dostime, &dosdate);
+ if (header[ZIP_CRYPTO_PKWARE_HEADERLEN - 1] == dostime >> 8) {
+ ok = true;
+ }
+ }
+
+ if (st.valid & ZIP_STAT_CRC) {
+ if (header[ZIP_CRYPTO_PKWARE_HEADERLEN - 1] == st.crc >> 24) {
+ ok = true;
+ }
+ }
+
+ if (!ok && ((st.valid & (ZIP_STAT_MTIME | ZIP_STAT_CRC)) != 0)) {
+ 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:
+ _zip_pkware_keys_reset(&ctx->keys);
+ _zip_pkware_decrypt(&ctx->keys, NULL, (const zip_uint8_t *)ctx->password, strlen(ctx->password));
+ 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;
+ }
+
+ _zip_pkware_decrypt(&ctx->keys, (zip_uint8_t *)data, (zip_uint8_t *)data, (zip_uint64_t)n);
+ 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;
+ if (st->valid & ZIP_STAT_COMP_SIZE) {
+ st->comp_size -= ZIP_CRYPTO_PKWARE_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:
+ trad_pkware_free(ctx);
+ return 0;
+
+ default:
+ zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
+ return -1;
+ }
+}
+
+
+static struct trad_pkware *
+trad_pkware_new(const char *password, zip_error_t *error) {
+ struct trad_pkware *ctx;
+
+ if ((ctx = (struct trad_pkware *)malloc(sizeof(*ctx))) == NULL) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ return NULL;
+ }
+
+ if ((ctx->password = strdup(password)) == NULL) {
+ zip_error_set(error, ZIP_ER_MEMORY, 0);
+ free(ctx);
+ return NULL;
+ }
+
+ zip_error_init(&ctx->error);
+
+ return ctx;
+}
+
+
+static void
+trad_pkware_free(struct trad_pkware *ctx) {
+ if (ctx == NULL) {
+ return;
+ }
+
+ free(ctx->password);
+ free(ctx);
+}