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, 4 insertions, 2 deletions

diff --git a/agent/protect-tool.c b/agent/protect-tool.c
index 17f6fd559..c6450a20e 100644
--- a/agent/protect-tool.c
+++ b/agent/protect-tool.c
@@ -755,8 +755,9 @@ release_passphrase (char *pw)
 
 /* Stub function.  */
 int
-agent_key_available (const unsigned char *grip)
+agent_key_available (ctrl_t ctrl, const unsigned char *grip)
 {
+  (void)ctrl;
   (void)grip;
   return -1;  /* Not available.  */
 }
@@ -814,7 +815,7 @@ agent_askpin (ctrl_t ctrl,
 /* Replacement for the function in findkey.c.  Here we write the key
  * to stdout. */
 gpg_error_t
-agent_write_private_key (const unsigned char *grip,
+agent_write_private_key (ctrl_t ctrl, const unsigned char *grip,
                          const void *buffer, size_t length, int force,
                          const char *serialno, const char *keyref,
                          const char *dispserialno, time_t timestamp)
@@ -822,6 +823,7 @@ agent_write_private_key (const unsigned char *grip,
   char hexgrip[40+4+1];
   char *p;
 
+  (void)ctrl;
   (void)force;
   (void)serialno;
   (void)keyref;