1 files changed, 112 insertions, 0 deletions
diff --git a/src/Common/libzip/zip_pkware.c b/src/Common/libzip/zip_pkware.c
new file mode 100644
index 00000000..eb12b1e9
--- /dev/null
+++ b/src/Common/libzip/zip_pkware.c
@@ -0,0 +1,112 @@
+/*
+  zip_pkware.c -- Traditional PKWARE de/encryption backend 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 <zlib.h>
+
+#include "zipint.h"
+
+#define PKWARE_KEY0 305419896
+#define PKWARE_KEY1 591751049
+#define PKWARE_KEY2 878082192
+
+
+static void
+update_keys(zip_pkware_keys_t *keys, zip_uint8_t b) {
+    keys->key[0] = (zip_uint32_t)crc32(keys->key[0] ^ 0xffffffffUL, &b, 1) ^ 0xffffffffUL;
+    keys->key[1] = (keys->key[1] + (keys->key[0] & 0xff)) * 134775813 + 1;
+    b = (zip_uint8_t)(keys->key[1] >> 24);
+    keys->key[2] = (zip_uint32_t)crc32(keys->key[2] ^ 0xffffffffUL, &b, 1) ^ 0xffffffffUL;
+}
+
+
+static zip_uint8_t
+crypt_byte(zip_pkware_keys_t *keys) {
+    zip_uint16_t tmp;
+    tmp = (zip_uint16_t)(keys->key[2] | 2);
+    tmp = (zip_uint16_t)(((zip_uint32_t)tmp * (tmp ^ 1)) >> 8);
+    return (zip_uint8_t)tmp;
+}
+
+
+void
+_zip_pkware_keys_reset(zip_pkware_keys_t *keys) {
+    keys->key[0] = PKWARE_KEY0;
+    keys->key[1] = PKWARE_KEY1;
+    keys->key[2] = PKWARE_KEY2;
+}
+
+
+void
+_zip_pkware_encrypt(zip_pkware_keys_t *keys, zip_uint8_t *out, const zip_uint8_t *in, zip_uint64_t len) {
+    zip_uint64_t i;
+    zip_uint8_t b;
+    zip_uint8_t tmp;
+
+    for (i = 0; i < len; i++) {
+	b = in[i];
+
+	if (out != NULL) {
+	    tmp = crypt_byte(keys);
+	    update_keys(keys, b);
+	    b ^= tmp;
+	    out[i] = b;
+	}
+	else {
+	    /* during initialization, we're only interested in key updates */
+	    update_keys(keys, b);
+	}
+    }
+}
+
+
+void
+_zip_pkware_decrypt(zip_pkware_keys_t *keys, zip_uint8_t *out, const zip_uint8_t *in, zip_uint64_t len) {
+    zip_uint64_t i;
+    zip_uint8_t b;
+    zip_uint8_t tmp;
+
+    for (i = 0; i < len; i++) {
+	b = in[i];
+
+	/* during initialization, we're only interested in key updates */
+	if (out != NULL) {
+	    tmp = crypt_byte(keys);
+	    b ^= tmp;
+	    out[i] = b;
+	}
+
+	update_keys(keys, b);
+    }
+}