Ensure we can decrypt the luks key before attempting to use it

This just fails earlier when the wrong GPG key is used.

The correct solution is to avoid the failure by testing for GPG keys
before offering disks to boot.

1 files changed, 8 insertions, 2 deletions

diff --git a/src/initrd/btrfs-create.sh b/src/initrd/btrfs-create.sh
index 3066331..c076b9e 100644
--- a/src/initrd/btrfs-create.sh
+++ b/src/initrd/btrfs-create.sh
@@ -224,12 +224,18 @@ open_samizdat_blockdev_from_loop()
 open_samizdat_blockdev()
 {
   local dev="$1" keyfile="$2"
+  local cryptname=samizdatcrypt decrypted_keyfile=/luks.secret
 
-  local cryptname=samizdatcrypt
   gpg2 --verify "$keyfile" || return
+
+  # TODO: we should be ensuring we can decrypt this secret key before even
+  # offering the option to boot the encrypted filesystem
+
   # The first --decrypt merely strips the signature.  The option is
   # poorly named for that case.
-  gpg2 --decrypt "$keyfile" | gpg2 --decrypt | cryptsetup --key-file - luksOpen "$dev" "$cryptname" || return
+  gpg2 --decrypt "$keyfile" | gpg2 --decrypt > "$decrypted_keyfile" || return
+
+  cryptsetup --key-file "$decrypted_keyfile" luksOpen "$dev" "$cryptname" || return
 
   [ -b /dev/mapper/"$cryptname" ] || return