Add decryption of PGP/MIME-encrypted parts with --decrypt.

This adds support for decrypting PGP/MIME-encrypted parts to
notmuch-show and notmuch-reply.  The --decrypt option implies
--verify.  Once decryption (and possibly signature verification) is
done, a new part_encstatus formatter is emitted, the part_sigstatus
formatter is emitted, and the entire multipart/encrypted part is
replaced by the contents of the encrypted part.

At the moment only a json part_encstatus formatting function is
available, even though decryption is done for all formats.  Emacs
support to follow.

1 files changed, 8 insertions, 0 deletions

diff --git a/notmuch.c b/notmuch.c
index cd3cb1b5..93f31944 100644
--- a/notmuch.c
+++ b/notmuch.c
@@ -302,6 +302,14 @@ static command_t commands[] = {
       "\t\treported (currently only supported with --format=json) and\n"
       "\t\tthe multipart/signed part will be replaced by the signed data.\n"
       "\n"
+      "\t--decrypt\n"
+      "\n"
+      "\t\tDecrypt any MIME encrypted parts found in the selected content\n"
+      "\t\t(ie. \"multipart/encrypted\" parts). Status of the decryption\n"
+      "\t\twill be reported (currently only supported with --format=json)\n"
+      "\t\tand the multipart/encrypted part will be replaced by the\n"
+      "\t\tdecrypted content.\n"
+      "\n"
       "\n"
       "\tA common use of \"notmuch show\" is to display a single\n"
       "\tthread of email messages. For this, use a search term of\n"