gpg,gpgsm: Record the creation time of a private key.

* sm/call-agent.c (gpgsm_agent_genkey): Pass --timestamp option.
(gpgsm_agent_import_key): Ditto.
* g10/call-agent.c (agent_genkey): Add arg timestamp and pass it on.
(agent_import_key): Ditto.
* g10/import.c (transfer_secret_keys): Pass the creation date to the
agent.
* g10/keygen.c (common_gen): Ditto.
--

Having the creation time in the private key file makes it a lot easier
to re-create an OpenPGP public keyblock in case it was accidentally
lost.

Signed-off-by: Werner Koch <wk@gnupg.org>
Cherry-picked-from-master: 4031c42bfd

g10/keygen.c

@@ -1367,7 +1367,7 @@ common_gen (const char *keyparms, int algo, const char *algoelem,
 
   err = agent_genkey (NULL, cache_nonce_addr, passwd_nonce_addr, keyparms,
                       !!(keygen_flags & KEYGEN_FLAG_NO_PROTECTION),
-                      passphrase,
+                      passphrase, timestamp,
                       &s_key);
   if (err)
     {