xarchiver/debian-bug-959914_part3.patch
2020-07-28 15:51:55 +08:00

113 lines
3.2 KiB
Diff

From 62249180ee80494fc74ea3731af9bd52a78d1e02 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ingo=20Br=C3=BCckl?= <ib@wupperonline.de>
Date: Wed, 17 Jun 2020 21:40:59 +0200
Subject: [PATCH] Handle header encrypted multi-volume 7zip archives
Keep skipping volumes until the offset is reached and proceed
with is7zip_mhe() to detect header encryption as before.
This fixes github issue #92, reported by Ski-lleR.
---
src/7zip.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 63 insertions(+), 3 deletions(-)
diff --git a/src/7zip.c b/src/7zip.c
index 54ceb956..71bba0cd 100644
--- a/src/7zip.c
+++ b/src/7zip.c
@@ -17,6 +17,7 @@
*/
#include <string.h>
+#include <glib/gstdio.h>
#include "7zip.h"
#include "gzip_et_al.h"
#include "interface.h"
@@ -29,9 +30,67 @@
static gboolean data_line, encrypted, last_line;
-static void xa_7zip_seek_position (GIOChannel *file, gint64 offset, GSeekType type)
+static void xa_7zip_seek_position (const gchar *filename, GIOChannel **file, gint64 offset, GSeekType type)
{
- g_io_channel_seek_position(file, offset, type, NULL);
+ gchar byte;
+
+ g_io_channel_seek_position(*file, offset, type, NULL);
+
+ /* check whether it's a volume. i.e. whether offset is beyond the end of the file */
+ if (g_io_channel_read_chars(*file, &byte, sizeof(byte), NULL, NULL) == G_IO_STATUS_NORMAL)
+ /* doesn't seem so - back to requested position */
+ g_io_channel_seek_position(*file, -(gint64) sizeof(byte), G_SEEK_CUR, NULL);
+ else /* find the volume the offset is pointing to */
+ {
+ guint64 position, volsizes = 0;
+ gchar *fvname;
+ size_t ext;
+ guint i;
+ GStatBuf st;
+ GIOChannel *fnew;
+
+ if (!g_str_has_suffix(filename, ".001"))
+ return;
+
+ position = 12 + 8 + (guint64) offset; // absolute position
+
+ fvname = g_strdup(filename);
+ ext = strlen(fvname) - 4;
+
+ /* check volumes ... */
+ for (i = 1; i < 1000; i++)
+ {
+ fvname[ext] = 0;
+ sprintf(fvname, "%s.%03u", fvname, i);
+
+ if (!g_file_test(fvname, G_FILE_TEST_EXISTS) || (g_stat(fvname, &st) != 0))
+ break;
+
+ volsizes += (guint64) st.st_size;
+
+ /* ... up to the one we're looking for */
+ if (volsizes > position)
+ {
+ fnew = g_io_channel_new_file(fvname, "r", NULL);
+
+ if (!fnew)
+ break;
+
+ /* switch to volume */
+
+ g_io_channel_shutdown(*file, FALSE, NULL);
+
+ *file = fnew;
+
+ g_io_channel_set_encoding(*file, NULL, NULL);
+ g_io_channel_seek_position(*file, position - (volsizes - (guint64) st.st_size), G_SEEK_SET, NULL);
+
+ break;
+ }
+ }
+
+ g_free(fvname);
+ }
}
static void xa_7zip_uint64_skip (GIOChannel *file)
@@ -78,6 +137,7 @@ gboolean is7zip_mhe (const gchar *filename)
if (file)
{
g_io_channel_set_encoding(file, NULL, NULL);
+ g_io_channel_set_buffered(file, FALSE);
/* skip signature, version and header CRC32 */
g_io_channel_seek_position(file, 12, G_SEEK_SET, NULL);
@@ -90,7 +150,7 @@ gboolean is7zip_mhe (const gchar *filename)
}
/* skip next header size and CRC32 */
- xa_7zip_seek_position(file, 12 + offset, G_SEEK_CUR);
+ xa_7zip_seek_position(filename, &file, 12 + offset, G_SEEK_CUR);
/* header info */
g_io_channel_read_chars(file, &byte, sizeof(byte), NULL, NULL);