From 6186637cc9a4cbe4964ae0ca2aa00ed1738fc6a4 Mon Sep 17 00:00:00 2001 From: Werner Koch Date: Mon, 23 Feb 2015 13:10:57 +0100 Subject: doc: Add warning note about not acting as an oracle to --batch. -- --- doc/gpg.texi | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) diff --git a/doc/gpg.texi b/doc/gpg.texi index 67dc3d089..d311732fc 100644 --- a/doc/gpg.texi +++ b/doc/gpg.texi @@ -949,12 +949,23 @@ Try to be as quiet as possible. @opindex batch @opindex no-batch Use batch mode. Never ask, do not allow interactive commands. -@option{--no-batch} disables this option. Note that even with a -filename given on the command line, gpg might still need to read from -STDIN (in particular if gpg figures that the input is a -detached signature and no data file has been specified). Thus if you -do not want to feed data via STDIN, you should connect STDIN to -@file{/dev/null}. +@option{--no-batch} disables this option. This option is commonly +used for unattended operations. + +WARNING: Unattended operation bears a higher risk of being exposed to +security attacks. In particular any unattended use of GnuPG which +involves the use of secret keys should take care not to provide an +decryption oracle. There are several standard pre-cautions against +being used as an oracle. For example never return detailed error +messages or any diagnostics printed by your software to the remote +site. Consult with an expert in case of doubt. + +Note that even with a filename given on the command line, gpg might +still need to read from STDIN (in particular if gpg figures that the +input is a detached signature and no data file has been specified). +Thus if you do not want to feed data via STDIN, you should connect +STDIN to @file{/dev/null}. + @item --no-tty @opindex no-tty -- cgit v1.2.3