agent: Add "ephemeral" Assuan option.

* agent/agent.h (struct ephemeral_private_key_s): New.
(struct server_control_s): Add ephemeral_mode and ephemeral_keys.
(GENKEY_FLAG_NO_PROTECTION, GENKEY_FLAG_PRESET): New.
* agent/genkey.c (clear_ephemeral_keys): New.
(store_key): Add arg ctrl and implement ephemeral_mode.  Change all
callers.
(agent_genkey): Replace args no_protection and preset by a generic new
flags arg.
* agent/findkey.c (wipe_and_fclose): New.
(agent_write_private_key): Add arg ctrl and implement ephemeral_mode.
Change all callers.
(agent_update_private_key): Ditto
(read_key_file): Ditto.
(agent_key_available): Ditto.
* agent/command-ssh.c (card_key_available): Do not update display s/n
in ephemeral mode.  This is however enver triggred.
* agent/gpg-agent.c (agent_deinit_default_ctrl): Cleanup ephemeral
keys.
* agent/command.c (cmd_genkey): Use the new flags instead of separate
vars.
(cmd_readkey): Create a shadow key only in non-ephemeral_mode.
(cmd_getinfo): Add sub-command "ephemeral".
(option_handler): Add option "ephemeral".
--

The idea here that a session can be switched in an ephemeral mode
which does not store or read keys from disk but keeps them local to
the session.

GnuPG-bug-id: 6944

1 files changed, 6 insertions, 4 deletions

diff --git a/agent/cvt-openpgp.c b/agent/cvt-openpgp.c
index 6aad35bff..50755c0fd 100644
--- a/agent/cvt-openpgp.c
+++ b/agent/cvt-openpgp.c
@@ -969,7 +969,7 @@ convert_from_openpgp_main (ctrl_t ctrl, gcry_sexp_t s_pgp, int dontcare_exist,
   if (err)
     goto leave;
 
-  if (!dontcare_exist && !from_native && !agent_key_available (grip))
+  if (!dontcare_exist && !from_native && !agent_key_available (ctrl, grip))
     {
       err = gpg_error (GPG_ERR_EEXIST);
       goto leave;
@@ -1147,14 +1147,16 @@ convert_from_openpgp_native (ctrl_t ctrl,
           if (!agent_protect (*r_key, passphrase,
                               &protectedkey, &protectedkeylen,
                               ctrl->s2k_count))
-            agent_write_private_key (grip, protectedkey, protectedkeylen, 1,
-                                     NULL, NULL, NULL, 0);
+            agent_write_private_key (ctrl, grip,
+                                     protectedkey,
+                                     protectedkeylen,
+                                     1, NULL, NULL, NULL, 0);
           xfree (protectedkey);
         }
       else
         {
           /* Empty passphrase: write key without protection.  */
-          agent_write_private_key (grip,
+          agent_write_private_key (ctrl, grip,
                                    *r_key,
                                    gcry_sexp_canon_len (*r_key, 0, NULL,NULL),
                                    1, NULL, NULL, NULL, 0);