[gcab] Add header reserve space for signing

[Marc-Andre Lureau <malureau src gnome org>]

commit 20d27126f03f63acf376005c35ad907e5883f08f
Author: Marc-Andrà Lureau <marcandre lureau gmail com>
Date:   Tue Feb 12 17:50:50 2013 +0100

    Add header reserve space for signing

 gcab.1.in              |    3 +++
 gcab.c                 |    9 +++++++++
 libgcab/cabinet.c      |   11 +++++++++++
 libgcab/gcab-cabinet.c |   13 +++++++++++--
 4 files changed, 34 insertions(+), 2 deletions(-)
---
diff --git a/gcab.1.in b/gcab.1.in
index 3f0e7f0..f4f0261 100644
--- a/gcab.1.in
+++ b/gcab.1.in
@@ -24,6 +24,9 @@ create files without pathnames
 \fB\-C, --directory DIR\fR
 change or extract to directory DIR
 .TP
+\fB\-s, --space\fR
+Reserve space in cabinet for signing (e.g. -s 6144 reserves 6K bytes)
+.TP
 \fB\-v, --verbose\fR
 verbosely list files processed
 .TP
diff --git a/gcab.c b/gcab.c
index b99cce6..9fa86bf 100644
--- a/gcab.c
+++ b/gcab.c
@@ -77,6 +77,7 @@ main (int argc, char *argv[])
     gchar *change = NULL;
     int version = 0;
     int nopath = 0;
+    int space = 0;
     int compress = 0;
     int list = 0;
     int create = 0;
@@ -90,6 +91,7 @@ main (int argc, char *argv[])
         { "directory", 'C', 0, G_OPTION_ARG_FILENAME, &change, N_("Change to directory DIR"), N_("DIR") },
         { "zip", 'z', 0, G_OPTION_ARG_NONE, &compress, N_("Use zip compression"), NULL },
         { "nopath", 'n', 0, G_OPTION_ARG_NONE, &nopath, N_("Do not include path"), NULL },
+        { "space", 's', 0, G_OPTION_ARG_INT, &space, N_("Reserve space in cabinet for signing (e.g. -s 6144 reserves 6K bytes)"), NULL },
         { G_OPTION_REMAINING, '\0', 0, G_OPTION_ARG_FILENAME_ARRAY, &args, NULL, N_("FILE INPUT_FILES...") },
         { NULL }
     };
@@ -171,6 +173,13 @@ individual files from the archive.\
     if (args[1] == NULL)
         gcab_error (_("please specify input files."));
 
+    if (space) {
+        GByteArray *reserved = g_byte_array_sized_new (space);
+        g_byte_array_set_size (reserved, space);
+        g_object_set (cabinet, "reserved", reserved, NULL);
+        g_byte_array_unref (reserved);
+    }
+
     folder = gcab_folder_new (compress ? GCAB_COMPRESSION_MSZIP : 0);
 
     for (i = 1; args[i]; i++) {
diff --git a/libgcab/cabinet.c b/libgcab/cabinet.c
index 518026c..cdcd4dd 100644
--- a/libgcab/cabinet.c
+++ b/libgcab/cabinet.c
@@ -157,6 +157,8 @@ G_GNUC_INTERNAL gboolean
 cheader_write (cheader_t *ch, GDataOutputStream *out,
                GCancellable *cancellable, GError **error)
 {
+    GOutputStream *stream = g_filter_output_stream_get_base_stream (G_FILTER_OUTPUT_STREAM (out));
+
     if (!W1 ('M') || !W1 ('S') || !W1 ('C') || !W1 ('F') ||
         !W4 (ch->res1) ||
         !W4 (ch->size) ||
@@ -172,6 +174,15 @@ cheader_write (cheader_t *ch, GDataOutputStream *out,
         !W2 (ch->cabID))
         return FALSE;
 
+    if (ch->flags & CABINET_HEADER_RESERVE) {
+        W2 (ch->res_header);
+        W1 (ch->res_folder);
+        W1 (ch->res_data);
+        if (g_output_stream_write (stream, ch->reserved, ch->res_header,
+                                   cancellable, error) == -1)
+            return FALSE;
+    }
+
     return TRUE;
 }
 
diff --git a/libgcab/gcab-cabinet.c b/libgcab/gcab-cabinet.c
index e5f10ce..ec50a93 100644
--- a/libgcab/gcab-cabinet.c
+++ b/libgcab/gcab-cabinet.c
@@ -209,12 +209,21 @@ gcab_cabinet_write (GCabCabinet *self,
     dstream = g_data_output_stream_new (out);
     g_data_output_stream_set_byte_order (dstream, G_DATA_STREAM_BYTE_ORDER_LITTLE_ENDIAN);
 
+    if (self->reserved) {
+        header.offsetfiles += self->reserved->len + 4;
+        header.flags = CABINET_HEADER_RESERVE;
+        header.res_header = self->reserved->len;
+        header.res_folder = 0;
+        header.res_data = 0;
+        header.reserved = self->reserved->data;
+    }
+
     files = gcab_folder_get_files (cabfolder);
     for (l = files; l != NULL; l = l->next)
         sumstr += strlen (GCAB_FILE (l->data)->name) + 1;
 
     folder.typecomp = cabfolder->comptype;
-    folder.offsetdata = CFI_START + nfiles * 16 + sumstr;
+    folder.offsetdata = header.offsetfiles + nfiles * 16 + sumstr;
     folder.ndatab = gcab_folder_get_ndatablocks (cabfolder);
 
     /* avoid seeking to allow growing output streams */
@@ -257,7 +266,7 @@ gcab_cabinet_write (GCabCabinet *self,
         goto end;
 
     header.nfiles = nfiles;
-    header.size += CFI_START + nfiles * 16; /* 1st part cfile struct = 16 bytes */
+    header.size += header.offsetfiles + nfiles * 16; /* 1st part cfile struct = 16 bytes */
     header.size += sumstr;
 
     if (!cheader_write (&header, dstream, cancellable, error))