From 9b47ae89c3840eb2af9a57a885e19ccbe36957d5 Mon Sep 17 00:00:00 2001
From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Date: Fri, 20 Feb 2009 01:39:29 -0500
Subject: [PATCH] trivial implementation of monkeysphere-host revoke-key: just
 prints ascii-armored revocation certificate to stdout, and admin is expected
 to know what to do with it.

---
 man/man8/monkeysphere-host.8 |  7 +++++--
 src/share/mh/revoke_key      | 28 ++++++++++++++++++++++++++--
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/man/man8/monkeysphere-host.8 b/man/man8/monkeysphere-host.8
index 2b71807..2ccaaec 100644
--- a/man/man8/monkeysphere-host.8
+++ b/man/man8/monkeysphere-host.8
@@ -66,8 +66,11 @@ or by specifying `-` to load from stdin.  `o' may be be used in place
 of `add-revoker'.
 .TP
 .B revoke-key
-Revoke the host's OpenPGP key.  `r' may be used in place of
-`revoke-key'.
+Revoke the host's OpenPGP key.  This will ask you a series of
+questions, and then generate a key revocation certificate on standard
+out.  If you publish this revocation certificate to the public
+keyservers, your host key will be permanently revoked.  `r' may be
+used in place of `revoke-key'.
 .TP
 .B publish-key
 Publish the host's OpenPGP key to the keyserver.  `p' may be used in
diff --git a/src/share/mh/revoke_key b/src/share/mh/revoke_key
index cccdc22..380236b 100644
--- a/src/share/mh/revoke_key
+++ b/src/share/mh/revoke_key
@@ -15,7 +15,31 @@
 
 revoke_key() {
 
-# FIXME: implement!
-failure "not implemented yet!"
+# Coming in here, we expect $HOST_FINGERPRINT to be set, and we
+# believe that there is in fact a key.
 
+    # our current implementation is very simple: we just want to
+    # generate the revocation certificate on stdout.  This provides
+    # for the two most likely (but hopefully not common) scenarios:
+
+    # an admin wants a revocation certificate for the host which they
+    # can store securely offline.  In this case, the admin can
+    # redirect stdout to a file, or can simply copy/paste or
+    # transcribe from the terminal.
+
+    # Alternately, an admin might want to publish the revocation
+    # certificate immediately.  here's a quick way to do this:
+
+
+    # tmp=$(mktemp -d)
+    # export GNUPGHOME="$tmp"
+    # gpg --import < /var/lib/monkeysphere/ssh_host_rsa_key.pub.gpg
+    # monkeysphere-host revoke-key | gpg --import
+    # gpg --keyserver pool.sks-keyservers.net --send $(hostname -f)
+
+
+    # note: we're not using the gpg_host function because we actually
+    # want to use gpg's UI in this case, so we want to omit --no-tty
+
+    GNUPGHOME="$GNUPGHOME_HOST" gpg --no-greeting --quiet --armor --gen-revoke "0x${HOST_FINGERPRINT}!"
 }
-- 
2.26.2