[tor-bugs] #16685 [Tor]: Abnormal behavior when signing key expires if Ed25519 master ID key is offline (missing from /datadirectory/keys)

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#16685: Abnormal behavior when signing key expires if Ed25519 master ID key is
offline (missing from /datadirectory/keys)
------------------------+------------------------------------------
     Reporter:  s7r     |      Owner:
         Type:  defect  |     Status:  new
     Priority:  normal  |  Milestone:  Tor: 0.2.7.x-final
    Component:  Tor     |    Version:  Tor: 0.2.7.2-alpha
   Resolution:          |   Keywords:  ed25519 key, offline id keys
Actual Points:          |  Parent ID:
       Points:          |
------------------------+------------------------------------------

Comment (by s7r):

 Found a part of what was wrong.

 The signing key and key-cert were generated in /datadirectory/keys by Tor
 before I changed the SigningKeyLifetime to 2 (so assume the key-cert was
 generated with a default validity period of 30 days). After I changed
 SigningKeyLifetime to 2 in torrc, I have reloaded Tor but left the old
 signing key and key-cert in /datadirectory/keys as they were with validity
 period of 30 days (only exported the ed25519 master ID key).

 I have deleted the signing key manually and the key cert from
 /datadirectory/keys. Now Tor won't start:

 Jul 29 03:37:44.000 [warn] Missing identity key
 Jul 29 03:37:44.000 [err] do_main_loop(): Bug: Error initializing keys;
 exiting (on Tor 0.2.7.2-alpha-dev )

 So this answers my question if it's using another unrequested ed25519
 identity: No, it is not.

 Also manually deleted /root/.tor/keys folder and it wasn't generated again
 when tried to start Tor and it failed. Still investigating why did that
 appear there in the first place.

 Now I have moved the previous initial Ed25519 master ID key which I
 exported offline to /var/lib/tor/keys, started Tor with SigningKeyLifetime
 2 days in torrc and it correclty gneerated signing key and key-cert and
 did not fail to start. Exported the ed25519 master ID key offline gain and
 tried a servie tor reload. I got this again:

 Jul 29 03:47:48.000 [notice] Received reload signal (hup). Reloading
 config and resetting internal state.
 Jul 29 03:47:48.000 [notice] Read configuration file "/usr/share/tor/tor-
 service-defaults-torrc".
 Jul 29 03:47:48.000 [notice] Configuration file "/etc/tor/torrc" not
 present, using reasonable defaults.
 Jul 29 03:47:48.000 [notice] Opening Socks listener on 127.0.0.1:9050
 Jul 29 03:47:48.000 [notice] Closing no-longer-configured Control listener
 on 127.0.0.1:9051
 Jul 29 03:47:48.000 [notice] Closing no-longer-configured OR listener on
 <ipv6>:port
 Jul 29 03:47:48.000 [notice] Closing no-longer-configured OR listener on
 <ipv4>:port

 The signing key and key-cert available now are valid for at least 48
 hours. If this is too short for Tor, it should warn accordingly, not
 ignore the torrc file in /etc/tor/torrc which worked few seconds before
 just fine.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/16685#comment:1>
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