Use pipefail and randomize intermediate encrypted.1.5

Matthew writes:

    If the initial decrypt fails then the rest of the line shouldn't
    continue, as it won't be a properly decrypted password being
    re-encrypted and written over the existing passfile.

    One solution to this would be to enable pipefail (set -o pipefail) -
    either just before, or at the start of this script.  This would
    cause the failure of any of the commands in a pipe to set the return
    status of the whole pipeline to non-zero (the last failed command's
    return code is used).

We take his suggestion with this patch. While we're at it, we take a
little bit extra care (though not too much extra care) to select a more
random intermediate password, in case folks have a strange habit of
using a dot-new extension on files.

Suggested-by: Matthew Richardson <m.richardson@ed.ac.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/password-store.sh b/src/password-store.sh
index 0d03520..a7a5604 100755
--- a/src/password-store.sh
+++ b/src/password-store.sh
@@ -4,6 +4,7 @@
 # This file is licensed under the GPLv2+. Please see COPYING for more information.
 
 umask "${PASSWORD_STORE_UMASK:-077}"
+set -o pipefail
 
 GPG_OPTS="--quiet --yes --compress-algo=none"
 GPG="gpg"
@@ -209,12 +210,13 @@ case "$command" in
 
 		if [[ $reencrypt -eq 1 ]]; then
 			find "$PREFIX/$id_path" -iname '*.gpg' | while read -r passfile; do
+				fake_uniqueness_safety="$RANDOM"
 				passfile_dir=${passfile%/*}
 				passfile_dir=${passfile_dir#$PREFIX}
 				passfile_dir=${passfile_dir#/}
 				set_gpg_recipients "$passfile_dir"
-				$GPG -d $GPG_OPTS "$passfile" | $GPG -e "${gpg_recipient_args[@]}" -o "$passfile.new" $GPG_OPTS &&
-				mv -v "$passfile.new" "$passfile"
+				$GPG -d $GPG_OPTS "$passfile" | $GPG -e "${gpg_recipient_args[@]}" -o "$passfile.new.$fake_uniqueness_safety" $GPG_OPTS &&
+				mv -v "$passfile.new.$fake_uniqueness_safety" "$passfile"
 			done
 			git_add_file "$PREFIX/$id_path" "Reencrypted password store using new GPG id ${id_print}."
 		fi