1 files changed, 62 insertions, 0 deletions
diff --git a/archival/libunarchive/check_trailer_gzip.c b/archival/libunarchive/check_trailer_gzip.c
new file mode 100644
index 000000000..215e8293f
--- /dev/null
+++ b/archival/libunarchive/check_trailer_gzip.c
@@ -0,0 +1,62 @@
+/* vi: set sw=4 ts=4: */
+/*
+ *  busybox gunzip trailing header handler
+ *  Copyright Glenn McGrath 2002
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include "config.h"
+#include "busybox.h"
+#include "unarchive.h"
+
+extern unsigned int gunzip_crc;
+extern unsigned int gunzip_bytes_out;
+extern unsigned char *gunzip_in_buffer;
+extern unsigned char gunzip_in_buffer_count;
+
+extern void check_trailer_gzip(int src_fd)
+{
+
+	unsigned int stored_crc = 0;
+	unsigned char count;
+
+	/* top up the input buffer with the rest of the trailer */
+	xread_all(src_fd, &gunzip_in_buffer[gunzip_in_buffer_count], 8 - gunzip_in_buffer_count);
+	for (count = 0; count != 4; count++) {
+		stored_crc |= (gunzip_in_buffer[count] << (count * 8));
+	}
+
+	/* Validate decompression - crc */
+	if (stored_crc != (gunzip_crc ^ 0xffffffffL)) {
+		error_msg("invalid compressed data--crc error");
+	}
+
+	/* Validate decompression - size */
+	if (gunzip_bytes_out != 
+		(gunzip_in_buffer[4] | (gunzip_in_buffer[5] << 8) |
+		(gunzip_in_buffer[6] << 16) | (gunzip_in_buffer[7] << 24))) {
+		error_msg("invalid compressed data--length error");
+	}
+
+}