--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libzip/lib/zip_source_pkware.c	Wed Feb 24 21:19:28 2016 +0100
@@ -0,0 +1,226 @@
+/*
+  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);
+}