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

11 files changed, 497 insertions, 207 deletions

diff --git a/agent/agent.h b/agent/agent.h
index 531fad210..f0b2a334e 100644
--- a/agent/agent.h
+++ b/agent/agent.h
@@ -225,6 +225,17 @@ typedef struct ssh_control_file_s *ssh_control_file_t;
 /* Forward reference for local definitions in call-scd.c.  */
 struct daemon_local_s;
 
+/* Object to hold ephemeral secret keys.  */
+struct ephemeral_private_key_s
+{
+  struct ephemeral_private_key_s *next;
+  unsigned char grip[KEYGRIP_LEN];
+  unsigned char *keybuf;  /* Canon-s-exp with the private key (malloced). */
+  size_t keybuflen;
+};
+typedef struct ephemeral_private_key_s *ephemeral_private_key_t;
+
+
 /* Collection of data per session (aka connection). */
 struct server_control_s
 {
@@ -246,6 +257,12 @@ struct server_control_s
   /* Private data of the daemon (call-XXX.c). */
   struct daemon_local_s *d_local[DAEMON_MAX_TYPE];
 
+  /* Linked list with ephemeral stored private keys.  */
+  ephemeral_private_key_t ephemeral_keys;
+
+  /* If set functions will lookup keys in the ephemeral_keys list.  */
+  int ephemeral_mode;
+
   /* Environment settings for the connection.  */
   session_env_t session_env;
   char *lc_ctype;
@@ -452,7 +469,8 @@ void start_command_handler_ssh (ctrl_t, gnupg_fd_t);
 /*-- findkey.c --*/
 gpg_error_t agent_modify_description (const char *in, const char *comment,
                                       const gcry_sexp_t key, char **result);
-gpg_error_t agent_write_private_key (const unsigned char *grip,
+gpg_error_t 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,
@@ -477,7 +495,7 @@ gpg_error_t agent_ssh_key_from_file (ctrl_t ctrl,
                                      gcry_sexp_t *result, int *r_order);
 int agent_pk_get_algo (gcry_sexp_t s_key);
 int agent_is_tpm2_key(gcry_sexp_t s_key);
-int agent_key_available (const unsigned char *grip);
+int agent_key_available (ctrl_t ctrl, const unsigned char *grip);
 gpg_error_t agent_key_info_from_file (ctrl_t ctrl, const unsigned char *grip,
                                       int *r_keytype,
                                       unsigned char **r_shadow_info,
@@ -485,7 +503,8 @@ gpg_error_t agent_key_info_from_file (ctrl_t ctrl, const unsigned char *grip,
 gpg_error_t agent_delete_key (ctrl_t ctrl, const char *desc_text,
                               const unsigned char *grip,
                               int force, int only_stubs);
-gpg_error_t agent_update_private_key (const unsigned char *grip, nvc_t pk);
+gpg_error_t agent_update_private_key (ctrl_t ctrl,
+                                      const unsigned char *grip, nvc_t pk);
 
 /*-- call-pinentry.c --*/
 void initialize_module_call_pinentry (void);
@@ -541,15 +560,21 @@ gpg_error_t agent_pkdecrypt (ctrl_t ctrl, const char *desc_text,
 #define CHECK_CONSTRAINTS_NOT_EMPTY  1
 #define CHECK_CONSTRAINTS_NEW_SYMKEY 2
 
+#define GENKEY_FLAG_NO_PROTECTION 1
+#define GENKEY_FLAG_PRESET        2
+
+void clear_ephemeral_keys (ctrl_t ctrl);
+
 int check_passphrase_constraints (ctrl_t ctrl, const char *pw,
                                   unsigned int flags,
 				  char **failed_constraint);
 gpg_error_t agent_ask_new_passphrase (ctrl_t ctrl, const char *prompt,
                                       char **r_passphrase);
-int agent_genkey (ctrl_t ctrl, const char *cache_nonce, time_t timestamp,
+int agent_genkey (ctrl_t ctrl, unsigned int flags,
+                  const char *cache_nonce, time_t timestamp,
                   const char *keyparam, size_t keyparmlen,
-                  int no_protection, const char *override_passphrase,
-                  int preset, membuf_t *outbuf);
+                  const char *override_passphrase,
+                  membuf_t *outbuf);
 gpg_error_t agent_protect_and_store (ctrl_t ctrl, gcry_sexp_t s_skey,
                                      char **passphrase_addr);
 
@@ -587,7 +612,7 @@ gpg_error_t s2k_hash_passphrase (const char *passphrase, int hashalgo,
                                  const unsigned char *s2ksalt,
                                  unsigned int s2kcount,
                                  unsigned char *key, size_t keylen);
-gpg_error_t agent_write_shadow_key (const unsigned char *grip,
+gpg_error_t agent_write_shadow_key (ctrl_t ctrl, const unsigned char *grip,
                                     const char *serialno, const char *keyid,
                                     const unsigned char *pkbuf, int force,
                                     const char *dispserialno);
diff --git a/agent/command-ssh.c b/agent/command-ssh.c
index ca3993321..189acd7f8 100644
--- a/agent/command-ssh.c
+++ b/agent/command-ssh.c
@@ -2430,14 +2430,14 @@ card_key_available (ctrl_t ctrl, const struct card_key_info_s *keyinfo,
     }
 
   hex2bin (keyinfo->keygrip, grip, sizeof (grip));
-  if ( agent_key_available (grip) )
+  if (!ctrl->ephemeral_mode && agent_key_available (ctrl, grip) )
     {
       char *dispserialno;
 
       /* (Shadow)-key is not available in our key storage.  */
       agent_card_getattr (ctrl, "$DISPSERIALNO", &dispserialno,
                           keyinfo->keygrip);
-      err = agent_write_shadow_key (grip, keyinfo->serialno,
+      err = agent_write_shadow_key (ctrl, grip, keyinfo->serialno,
                                     keyinfo->idstr, pkbuf, 0, dispserialno);
       xfree (dispserialno);
       if (err)
@@ -3222,7 +3222,7 @@ ssh_identity_register (ctrl_t ctrl, ssh_key_type_spec_t *spec,
 
   /* Check whether the key is already in our key storage.  Don't do
      anything then besides (re-)adding it to sshcontrol.  */
-  if ( !agent_key_available (key_grip_raw) )
+  if ( !agent_key_available (ctrl, key_grip_raw) )
     goto key_exists; /* Yes, key is available.  */
 
   err = ssh_key_extract_comment (key, &comment);
@@ -3286,7 +3286,7 @@ ssh_identity_register (ctrl_t ctrl, ssh_key_type_spec_t *spec,
 
   /* Store this key to our key storage.  We do not store a creation
    * timestamp because we simply do not know.  */
-  err = agent_write_private_key (key_grip_raw, buffer, buffer_n, 0,
+  err = agent_write_private_key (ctrl, key_grip_raw, buffer, buffer_n, 0,
                                  NULL, NULL, NULL, 0);
   if (err)
     goto out;
diff --git a/agent/command.c b/agent/command.c
index da91053d8..20ae08e9f 100644
--- a/agent/command.c
+++ b/agent/command.c
@@ -251,6 +251,9 @@ reset_notify (assuan_context_t ctx, char *line)
 
   clear_nonce_cache (ctrl);
 
+  /* Note that a RESET does not clear the ephemeral store becuase
+   * clients are used to issue a RESET on a connection.  */
+
   return 0;
 }
 
@@ -643,15 +646,15 @@ static const char hlp_havekey[] =
 static gpg_error_t
 cmd_havekey (assuan_context_t ctx, char *line)
 {
-  ctrl_t ctrl;
+  ctrl_t ctrl = assuan_get_pointer (ctx);
   gpg_error_t err;
   unsigned char grip[20];
   char *p;
   int list_mode = 0;  /* Less than 0 for no limit.  */
   int info_mode = 0;
   int counter;
-  char *dirname;
-  gnupg_dir_t dir;
+  char *dirname = NULL;
+  gnupg_dir_t dir = NULL;
   gnupg_dirent_t dir_entry;
   char hexgrip[41];
   struct card_key_info_s *keyinfo_on_cards, *l;
@@ -668,14 +671,11 @@ cmd_havekey (assuan_context_t ctx, char *line)
 
   line = skip_options (line);
 
-
   if (info_mode)
     {
       int keytype;
       const char *infostring;
 
-      ctrl = assuan_get_pointer (ctx);
-
       err = parse_keygrip (ctx, line, grip);
       if (err)
         goto leave;
@@ -706,7 +706,7 @@ cmd_havekey (assuan_context_t ctx, char *line)
           if (err)
             return err;
 
-          if (!agent_key_available (grip))
+          if (!agent_key_available (ctrl, grip))
             return 0; /* Found.  */
 
           while (*line && *line != ' ' && *line != '\t')
@@ -724,7 +724,6 @@ cmd_havekey (assuan_context_t ctx, char *line)
   /* List mode.  */
   dir = NULL;
   dirname = NULL;
-  ctrl = assuan_get_pointer (ctx);
 
   if (ctrl->restricted)
     {
@@ -1117,26 +1116,27 @@ cmd_genkey (assuan_context_t ctx, char *line)
 {
   ctrl_t ctrl = assuan_get_pointer (ctx);
   int rc;
-  int no_protection;
   unsigned char *value = NULL;
   size_t valuelen;
   unsigned char *newpasswd = NULL;
   membuf_t outbuf;
   char *cache_nonce = NULL;
   char *passwd_nonce = NULL;
-  int opt_preset;
   int opt_inq_passwd;
   size_t n;
   char *p, *pend;
   const char *s;
   time_t opt_timestamp;
   int c;
+  unsigned int flags = 0;
 
   if (ctrl->restricted)
     return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN));
 
-  no_protection = has_option (line, "--no-protection");
-  opt_preset = has_option (line, "--preset");
+  if (has_option (line, "--no-protection"))
+    flags |= GENKEY_FLAG_NO_PROTECTION;
+  if (has_option (line, "--preset"))
+    flags |= GENKEY_FLAG_PRESET;
   opt_inq_passwd = has_option (line, "--inq-passwd");
   passwd_nonce = option_value (line, "--passwd-nonce");
   if (passwd_nonce)
@@ -1191,7 +1191,7 @@ cmd_genkey (assuan_context_t ctx, char *line)
 
   /* If requested, ask for the password to be used for the key.  If
      this is not used the regular Pinentry mechanism is used.  */
-  if (opt_inq_passwd && !no_protection)
+  if (opt_inq_passwd && !(flags & GENKEY_FLAG_NO_PROTECTION))
     {
       /* (N is used as a dummy) */
       assuan_begin_confidential (ctx);
@@ -1204,16 +1204,17 @@ cmd_genkey (assuan_context_t ctx, char *line)
           /* Empty password given - switch to no-protection mode.  */
           xfree (newpasswd);
           newpasswd = NULL;
-          no_protection = 1;
+          flags |= GENKEY_FLAG_NO_PROTECTION;
         }
 
     }
   else if (passwd_nonce)
     newpasswd = agent_get_cache (ctrl, passwd_nonce, CACHE_MODE_NONCE);
 
-  rc = agent_genkey (ctrl, cache_nonce, opt_timestamp,
-                     (char*)value, valuelen, no_protection,
-                     newpasswd, opt_preset, &outbuf);
+
+  rc = agent_genkey (ctrl, flags, cache_nonce, opt_timestamp,
+                     (char*)value, valuelen,
+                     newpasswd, &outbuf);
 
  leave:
   if (newpasswd)
@@ -1317,7 +1318,7 @@ cmd_keyattr (assuan_context_t ctx, char *line)
           if (!err)
             err = nvc_set_private_key (keymeta, s_key);
           if (!err)
-            err = agent_update_private_key (grip, keymeta);
+            err = agent_update_private_key (ctrl, grip, keymeta);
         }
 
       nvc_release (keymeta);
@@ -1327,6 +1328,8 @@ cmd_keyattr (assuan_context_t ctx, char *line)
  leave:
   return leave_cmd (ctx, err);
 }
+
+
 
 static const char hlp_readkey[] =
   "READKEY [--no-data] [--format=ssh] <hexstring_with_keygrip>\n"
@@ -1390,7 +1393,7 @@ cmd_readkey (assuan_context_t ctx, char *line)
           goto leave;
         }
 
-      if (agent_key_available (grip))
+      if (!ctrl->ephemeral_mode && agent_key_available (ctrl, grip))
         {
           /* (Shadow)-key is not available in our key storage.  */
           char *dispserialno;
@@ -1398,7 +1401,7 @@ cmd_readkey (assuan_context_t ctx, char *line)
 
           bin2hex (grip, 20, hexgrip);
           agent_card_getattr (ctrl, "$DISPSERIALNO", &dispserialno, hexgrip);
-          rc = agent_write_shadow_key (grip, serialno, keyid, pkbuf, 0,
+          rc = agent_write_shadow_key (ctrl, grip, serialno, keyid, pkbuf, 0,
                                        dispserialno);
           xfree (dispserialno);
           if (rc)
@@ -2934,7 +2937,7 @@ cmd_import_key (assuan_context_t ctx, char *line)
     }
   else
     {
-      if (!force && !agent_key_available (grip))
+      if (!force && !agent_key_available (ctrl, grip))
         err = gpg_error (GPG_ERR_EEXIST);
       else
         {
@@ -2956,11 +2959,11 @@ cmd_import_key (assuan_context_t ctx, char *line)
       err = agent_protect (key, passphrase, &finalkey, &finalkeylen,
                            ctrl->s2k_count);
       if (!err)
-        err = agent_write_private_key (grip, finalkey, finalkeylen, force,
+        err = agent_write_private_key (ctrl, grip, finalkey, finalkeylen, force,
                                        NULL, NULL, NULL, opt_timestamp);
     }
   else
-    err = agent_write_private_key (grip, key, realkeylen, force,
+    err = agent_write_private_key (ctrl, grip, key, realkeylen, force,
                                    NULL, NULL, NULL, opt_timestamp);
 
  leave:
@@ -2979,7 +2982,8 @@ cmd_import_key (assuan_context_t ctx, char *line)
 
 
 static const char hlp_export_key[] =
-  "EXPORT_KEY [--cache-nonce=<nonce>] [--openpgp|--mode1003] <hexkeygrip>\n"
+  "EXPORT_KEY [--cache-nonce=<nonce>] \\\n"
+  "           [--openpgp|--mode1003] <hexkeygrip>\n"
   "\n"
   "Export a secret key from the key store.  The key will be encrypted\n"
   "using the current session's key wrapping key (cf. command KEYWRAP_KEY)\n"
@@ -2987,8 +2991,8 @@ static const char hlp_export_key[] =
   "prior to using this command.  The function takes the keygrip as argument.\n"
   "\n"
   "If --openpgp is used, the secret key material will be exported in RFC 4880\n"
-  "compatible passphrase-protected form.  If --mode1003 is use the secret key\n"
-  "is exported as s-expression as storred locally.  Without those options,\n"
+  "compatible passphrase-protected form.  In --mode1003 the secret key\n"
+  "is exported as s-expression as stored locally.  Without those options,\n"
   "the secret key material will be exported in the clear (after prompting\n"
   "the user to unlock it, if needed).\n";
 static gpg_error_t
@@ -3045,7 +3049,7 @@ cmd_export_key (assuan_context_t ctx, char *line)
   if (err)
     goto leave;
 
-  if (agent_key_available (grip))
+  if (agent_key_available (ctrl, grip))
     {
       err = gpg_error (GPG_ERR_NO_SECKEY);
       goto leave;
@@ -3257,9 +3261,9 @@ cmd_keytocard (assuan_context_t ctx, char *line)
   if (err)
     goto leave;
 
-  if (agent_key_available (grip))
+  if (agent_key_available (ctrl, grip))
     {
-      err =gpg_error (GPG_ERR_NO_SECKEY);
+      err = gpg_error (GPG_ERR_NO_SECKEY);
       goto leave;
     }
 
@@ -3577,7 +3581,7 @@ cmd_keytotpm (assuan_context_t ctx, char *line)
   if (err)
     goto leave;
 
-  if (agent_key_available (grip))
+  if (agent_key_available (ctrl, grip))
     {
       err =gpg_error (GPG_ERR_NO_SECKEY);
       goto leave;
@@ -3869,6 +3873,7 @@ static const char hlp_getinfo[] =
   "  getenv NAME     - Return value of envvar NAME.\n"
   "  connections     - Return number of active connections.\n"
   "  jent_active     - Returns OK if Libgcrypt's JENT is active.\n"
+  "  ephemeral       - Returns OK if the connection is in ephemeral mode.\n"
   "  restricted      - Returns OK if the connection is in restricted mode.\n"
   "  cmd_has_option CMD OPT\n"
   "                  - Returns OK if command CMD has option OPT.\n";
@@ -3922,6 +3927,10 @@ cmd_getinfo (assuan_context_t ctx, char *line)
       snprintf (numbuf, sizeof numbuf, "%lu", get_standard_s2k_count ());
       rc = assuan_send_data (ctx, numbuf, strlen (numbuf));
     }
+  else if (!strcmp (line, "ephemeral"))
+    {
+      rc = ctrl->ephemeral_mode? 0 : gpg_error (GPG_ERR_FALSE);
+    }
   else if (!strcmp (line, "restricted"))
     {
       rc = ctrl->restricted? 0 : gpg_error (GPG_ERR_FALSE);
@@ -4078,6 +4087,10 @@ option_handler (assuan_context_t ctx, const char *key, const char *value)
       ctrl->server_local->allow_fully_canceled =
         gnupg_compare_version (value, "2.1.0");
     }
+  else if (!strcmp (key, "ephemeral"))
+    {
+      ctrl->ephemeral_mode = *value? atoi (value) : 0;
+    }
   else if (ctrl->restricted)
     {
       err = gpg_error (GPG_ERR_FORBIDDEN);
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);
diff --git a/agent/divert-tpm2.c b/agent/divert-tpm2.c
index e7c6a8aae..2496d091a 100644
--- a/agent/divert-tpm2.c
+++ b/agent/divert-tpm2.c
@@ -57,7 +57,7 @@ agent_write_tpm2_shadow_key (ctrl_t ctrl, const unsigned char *grip,
     }
 
   len = gcry_sexp_canon_len (shdkey, 0, NULL, NULL);
-  err = agent_write_private_key (grip, shdkey, len, 1 /*force*/,
+  err = agent_write_private_key (ctrl, grip, shdkey, len, 1 /*force*/,
                                  NULL, NULL, NULL, 0);
   xfree (shdkey);
   if (err)
@@ -70,7 +70,7 @@ agent_write_tpm2_shadow_key (ctrl_t ctrl, const unsigned char *grip,
 	return GPG_ERR_ENOMEM;
 
       gcry_sexp_sprint(s_key, GCRYSEXP_FMT_CANON, pkbuf, len);
-      err1 = agent_write_private_key (grip, pkbuf, len, 1 /*force*/,
+      err1 = agent_write_private_key (ctrl, grip, pkbuf, len, 1 /*force*/,
 				      NULL, NULL, NULL, 0);
       xfree(pkbuf);
       if (err1)
diff --git a/agent/findkey.c b/agent/findkey.c
index 4e55119e3..1f2938ea3 100644
--- a/agent/findkey.c
+++ b/agent/findkey.c
@@ -40,7 +40,7 @@
 #endif
 
 
-static gpg_error_t read_key_file (const unsigned char *grip,
+static gpg_error_t read_key_file (ctrl_t ctrl, const unsigned char *grip,
                                   gcry_sexp_t *result, nvc_t *r_keymeta,
                                   char **r_orig_key_value);
 static gpg_error_t is_shadowed_key (gcry_sexp_t s_skey);
@@ -73,6 +73,30 @@ fname_from_keygrip (const unsigned char *grip, int for_new)
 }
 
 
+/* Helper until we have a "wipe" mode flag in es_fopen.  */
+static void
+wipe_and_fclose (estream_t fp)
+{
+  void *blob;
+  size_t blob_size;
+
+  if (!fp)
+    ;
+  else if (es_fclose_snatch (fp, &blob, &blob_size))
+    {
+      log_error ("error wiping buffer during fclose\n");
+      es_fclose (fp);
+    }
+  else if (blob)
+    {
+      wipememory (blob, blob_size);
+      gpgrt_free (blob);
+    }
+}
+
+
+
+
 /* Replace all linefeeds in STRING by "%0A" and return a new malloced
  * string.  May return NULL on memory error.  */
 static char *
@@ -110,7 +134,8 @@ linefeed_to_percent0A (const char *string)
  * TIMESTAMP is not zero and the key does not yet exists it will be
  * recorded as creation date.  */
 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,
@@ -120,7 +145,7 @@ agent_write_private_key (const unsigned char *grip,
   char *fname = NULL;
   char *tmpfname = NULL;
   estream_t fp = NULL;
-  int newkey;
+  int newkey = 0;
   nvc_t pk = NULL;
   gcry_sexp_t key = NULL;
   int removetmp = 0;
@@ -134,11 +159,13 @@ agent_write_private_key (const unsigned char *grip,
   const char *s;
   int force_modify = 0;
 
-  fname = fname_from_keygrip (grip, 0);
+  fname = (ctrl->ephemeral_mode
+           ? xtrystrdup ("[ephemeral key store]")
+           : fname_from_keygrip (grip, 0));
   if (!fname)
     return gpg_error_from_syserror ();
 
-  err = read_key_file (grip, &key, &pk, &orig_key_value);
+  err = read_key_file (ctrl, grip, &key, &pk, &orig_key_value);
   if (err)
     {
       if (gpg_err_code (err) == GPG_ERR_ENOENT)
@@ -289,43 +316,99 @@ agent_write_private_key (const unsigned char *grip,
       goto leave;
     }
 
-  /* Create a temporary file for writing.  */
-  tmpfname = fname_from_keygrip (grip, 1);
-  fp = tmpfname ? es_fopen (tmpfname, "wbx,mode=-rw") : NULL;
-  if (!fp)
+  if (ctrl->ephemeral_mode)
     {
-      err = gpg_error_from_syserror ();
-      log_error ("can't create '%s': %s\n", tmpfname, gpg_strerror (err));
-      goto leave;
-    }
+      ephemeral_private_key_t ek;
+      void *blob;
+      size_t blobsize;
 
-  err = nvc_write (pk, fp);
-  if (!err && es_fflush (fp))
-    err = gpg_error_from_syserror ();
-  if (err)
-    {
-      log_error ("error writing '%s': %s\n", tmpfname, gpg_strerror (err));
-      removetmp = 1;
-      goto leave;
-    }
+      for (ek = ctrl->ephemeral_keys; ek; ek = ek->next)
+        if (!memcmp (ek->grip, grip, KEYGRIP_LEN))
+          break;
+      if (!ek)
+        {
+          ek = xtrycalloc (1, sizeof *ek);
+          if (!ek)
+            {
+              err = gpg_error_from_syserror ();
+              goto leave;
+            }
+          memcpy (ek->grip, grip, KEYGRIP_LEN);
+          ek->next = ctrl->ephemeral_keys;
+          ctrl->ephemeral_keys = ek;
+        }
 
-  if (es_fclose (fp))
-    {
-      err = gpg_error_from_syserror ();
-      log_error ("error closing '%s': %s\n", tmpfname, gpg_strerror (err));
-      removetmp = 1;
-      goto leave;
+      fp = es_fopenmem (0, "wb,wipe");
+      if (!fp)
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("can't open memory stream: %s\n", gpg_strerror (err));
+          goto leave;
+        }
+
+      err = nvc_write (pk, fp);
+      if (err)
+        {
+          log_error ("error writing to memory stream: %s\n",gpg_strerror (err));
+          goto leave;
+        }
+
+      if (es_fclose_snatch (fp, &blob, &blobsize) || !blob)
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("error getting memory stream buffer: %s\n",
+                     gpg_strerror (err));
+          /* Closing right away so that we don't try another snatch in
+           * the cleanup.  */
+          es_fclose (fp);
+          fp = NULL;
+          goto leave;
+        }
+      fp = NULL;
+      xfree (ek->keybuf);
+      ek->keybuf = blob;
+      ek->keybuflen = blobsize;
     }
   else
-    fp = NULL;
-
-  err = gnupg_rename_file (tmpfname, fname, &blocksigs);
-  if (err)
     {
-      err = gpg_error_from_syserror ();
-      log_error ("error renaming '%s': %s\n", tmpfname, gpg_strerror (err));
-      removetmp = 1;
-      goto leave;
+      /* Create a temporary file for writing.  */
+      tmpfname = fname_from_keygrip (grip, 1);
+      fp = tmpfname ? es_fopen (tmpfname, "wbx,mode=-rw") : NULL;
+      if (!fp)
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("can't create '%s': %s\n", tmpfname, gpg_strerror (err));
+          goto leave;
+        }
+
+      err = nvc_write (pk, fp);
+      if (!err && es_fflush (fp))
+        err = gpg_error_from_syserror ();
+      if (err)
+        {
+          log_error ("error writing '%s': %s\n", tmpfname, gpg_strerror (err));
+          removetmp = 1;
+          goto leave;
+        }
+
+      if (es_fclose (fp))
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("error closing '%s': %s\n", tmpfname, gpg_strerror (err));
+          removetmp = 1;
+          goto leave;
+        }
+      else
+        fp = NULL;
+
+      err = gnupg_rename_file (tmpfname, fname, &blocksigs);
+      if (err)
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("error renaming '%s': %s\n", tmpfname, gpg_strerror (err));
+          removetmp = 1;
+          goto leave;
+        }
     }
 
   bump_key_eventcounter ();
@@ -333,7 +416,10 @@ agent_write_private_key (const unsigned char *grip,
  leave:
   if (blocksigs)
     gnupg_unblock_all_signals ();
-  es_fclose (fp);
+  if (ctrl->ephemeral_mode)
+    wipe_and_fclose (fp);
+  else
+    es_fclose (fp);
   if (removetmp && tmpfname)
     gnupg_remove (tmpfname);
   xfree (orig_key_value);
@@ -350,7 +436,7 @@ agent_write_private_key (const unsigned char *grip,
 
 
 gpg_error_t
-agent_update_private_key (const unsigned char *grip, nvc_t pk)
+agent_update_private_key (ctrl_t ctrl, const unsigned char *grip, nvc_t pk)
 {
   gpg_error_t err;
   char *fname0 = NULL;   /* The existing file name.  */
@@ -359,6 +445,57 @@ agent_update_private_key (const unsigned char *grip, nvc_t pk)
   int removetmp = 0;
   int blocksigs = 0;
 
+  if (ctrl->ephemeral_mode)
+    {
+      ephemeral_private_key_t ek;
+      void *blob;
+      size_t blobsize;
+
+      for (ek = ctrl->ephemeral_keys; ek; ek = ek->next)
+        if (!memcmp (ek->grip, grip, KEYGRIP_LEN))
+          break;
+      if (!ek)
+        {
+          err = gpg_error (GPG_ERR_ENOENT);
+          goto leave;
+        }
+
+      fp = es_fopenmem (0, "wbx,wipe");
+      if (!fp)
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("can't open memory stream: %s\n", gpg_strerror (err));
+          goto leave;
+        }
+
+      err = nvc_write (pk, fp);
+      if (err)
+        {
+          log_error ("error writing to memory stream: %s\n",gpg_strerror (err));
+          goto leave;
+        }
+
+      if (es_fclose_snatch (fp, &blob, &blobsize) || !blob)
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("error getting memory stream buffer: %s\n",
+                     gpg_strerror (err));
+          /* Closing right away so that we don't try another snatch in
+           * the cleanup.  */
+          es_fclose (fp);
+          fp = NULL;
+          goto leave;
+        }
+      fp = NULL;
+      /* No need to revisit the linked list because the found EK is
+       * not expected to change due to the other syscalls above.  */
+      xfree (ek->keybuf);
+      ek->keybuf = blob;
+      ek->keybuflen = blobsize;
+      goto leave;
+    }
+
+
   fname0 = fname_from_keygrip (grip, 0);
   if (!fname0)
     {
@@ -404,7 +541,10 @@ agent_update_private_key (const unsigned char *grip, nvc_t pk)
  leave:
   if (blocksigs)
     gnupg_unblock_all_signals ();
-  es_fclose (fp);
+  if (ctrl->ephemeral_mode)
+    wipe_and_fclose (fp);
+  else
+    es_fclose (fp);
   if (removetmp && fname)
     gnupg_remove (fname);
   xfree (fname);
@@ -888,17 +1028,17 @@ unprotect (ctrl_t ctrl, const char *cache_nonce, const char *desc_text,
  * caller must free it.  On failure returns an error code and stores
  * NULL at RESULT and R_KEYMETA. */
 static gpg_error_t
-read_key_file (const unsigned char *grip, gcry_sexp_t *result, nvc_t *r_keymeta,
-               char **r_orig_key_value)
+read_key_file (ctrl_t ctrl, const unsigned char *grip,
+               gcry_sexp_t *result, nvc_t *r_keymeta, char **r_orig_key_value)
 {
   gpg_error_t err;
   char *fname;
-  estream_t fp;
-  struct stat st;
-  unsigned char *buf;
+  estream_t fp = NULL;
+  unsigned char *buf = NULL;
   size_t buflen, erroff;
-  gcry_sexp_t s_skey;
+  nvc_t pk = NULL;
   char first;
+  size_t keybuflen;
 
   *result = NULL;
   if (r_keymeta)
@@ -906,19 +1046,42 @@ read_key_file (const unsigned char *grip, gcry_sexp_t *result, nvc_t *r_keymeta,
   if (r_orig_key_value)
     *r_orig_key_value = NULL;
 
-  fname = fname_from_keygrip (grip, 0);
+  fname = (ctrl->ephemeral_mode
+           ? xtrystrdup ("[ephemeral key store]")
+           : fname_from_keygrip (grip, 0));
   if (!fname)
     {
-      return gpg_error_from_syserror ();
+      err = gpg_error_from_syserror ();
+      goto leave;
+    }
+
+  if (ctrl->ephemeral_mode)
+    {
+      ephemeral_private_key_t ek;
+
+      for (ek = ctrl->ephemeral_keys; ek; ek = ek->next)
+        if (!memcmp (ek->grip, grip, KEYGRIP_LEN)
+            && ek->keybuf && ek->keybuflen)
+          break;
+      if (!ek || !ek->keybuf || !ek->keybuflen)
+        {
+          err = gpg_error (GPG_ERR_ENOENT);
+          goto leave;
+        }
+      keybuflen = ek->keybuflen;
+      fp = es_fopenmem_init (0, "rb", ek->keybuf, ek->keybuflen);
+    }
+  else
+    {
+      keybuflen = 0;  /* Indicates that this is not ephemeral mode.  */
+      fp = es_fopen (fname, "rb");
     }
-  fp = es_fopen (fname, "rb");
   if (!fp)
     {
       err = gpg_error_from_syserror ();
       if (gpg_err_code (err) != GPG_ERR_ENOENT)
         log_error ("can't open '%s': %s\n", fname, gpg_strerror (err));
-      xfree (fname);
-      return err;
+      goto leave;
     }
 
   if (es_fread (&first, 1, 1, fp) != 1)
@@ -926,28 +1089,22 @@ read_key_file (const unsigned char *grip, gcry_sexp_t *result, nvc_t *r_keymeta,
       err = gpg_error_from_syserror ();
       log_error ("error reading first byte from '%s': %s\n",
                  fname, gpg_strerror (err));
-      xfree (fname);
-      es_fclose (fp);
-      return err;
+      goto leave;
     }
 
   if (es_fseek (fp, 0, SEEK_SET))
     {
       err = gpg_error_from_syserror ();
       log_error ("error seeking in '%s': %s\n", fname, gpg_strerror (err));
-      xfree (fname);
-      es_fclose (fp);
-      return err;
+      goto leave;
     }
 
   if (first != '(')
     {
       /* Key is in extended format.  */
-      nvc_t pk = NULL;
       int line;
 
       err = nvc_parse_private_key (&pk, &line, fp);
-      es_fclose (fp);
 
       if (err)
         log_error ("error parsing '%s' line %d: %s\n",
@@ -969,9 +1126,7 @@ read_key_file (const unsigned char *grip, gcry_sexp_t *result, nvc_t *r_keymeta,
                       if (!*r_orig_key_value)
                         {
                           err = gpg_error_from_syserror ();
-                          nvc_release (pk);
-                          xfree (fname);
-                          return err;
+                          goto leave;
                         }
                     }
                 }
@@ -979,35 +1134,31 @@ read_key_file (const unsigned char *grip, gcry_sexp_t *result, nvc_t *r_keymeta,
             }
         }
 
-      if (!err && r_keymeta)
-        *r_keymeta = pk;
-      else
-        nvc_release (pk);
-      xfree (fname);
-      return err;
+      goto leave; /* Ready. */
     }
 
-  if (fstat (es_fileno (fp), &st))
+  if (keybuflen)
+    buflen = keybuflen;
+  else
     {
-      err = gpg_error_from_syserror ();
-      log_error ("can't stat '%s': %s\n", fname, gpg_strerror (err));
-      xfree (fname);
-      es_fclose (fp);
-      return err;
+      struct stat st;
+
+      if (fstat (es_fileno (fp), &st))
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("can't stat '%s': %s\n", fname, gpg_strerror (err));
+          goto leave;
+        }
+      buflen = st.st_size;
     }
 
-  buflen = st.st_size;
   buf = xtrymalloc (buflen+1);
   if (!buf)
     {
       err = gpg_error_from_syserror ();
       log_error ("error allocating %zu bytes for '%s': %s\n",
                  buflen, fname, gpg_strerror (err));
-      xfree (fname);
-      es_fclose (fp);
-      xfree (buf);
-      return err;
-
+      goto leave;
     }
 
   if (es_fread (buf, buflen, 1, fp) != 1)
@@ -1015,25 +1166,32 @@ read_key_file (const unsigned char *grip, gcry_sexp_t *result, nvc_t *r_keymeta,
       err = gpg_error_from_syserror ();
       log_error ("error reading %zu bytes from '%s': %s\n",
                  buflen, fname, gpg_strerror (err));
-      xfree (fname);
-      es_fclose (fp);
-      xfree (buf);
-      return err;
+      goto leave;
     }
 
   /* Convert the file into a gcrypt S-expression object.  */
-  err = gcry_sexp_sscan (&s_skey, &erroff, (char*)buf, buflen);
-  xfree (fname);
-  es_fclose (fp);
-  xfree (buf);
-  if (err)
-    {
+  {
+    gcry_sexp_t s_skey;
+
+    err = gcry_sexp_sscan (&s_skey, &erroff, (char*)buf, buflen);
+    if (err)
       log_error ("failed to build S-Exp (off=%u): %s\n",
                  (unsigned int)erroff, gpg_strerror (err));
-      return err;
-    }
-  *result = s_skey;
-  return 0;
+    else
+      *result = s_skey;
+  }
+
+ leave:
+  if (!err && r_keymeta)
+    *r_keymeta = pk;
+  else
+    nvc_release (pk);
+  if (ctrl->ephemeral_mode)
+    wipe_and_fclose (fp);
+   else
+    es_fclose (fp);
+  xfree (fname);
+  return err;
 }
 
 
@@ -1226,7 +1384,8 @@ agent_key_from_file (ctrl_t ctrl, const char *cache_nonce,
   if (!grip && !ctrl->have_keygrip)
     return gpg_error (GPG_ERR_NO_SECKEY);
 
-  err = read_key_file (grip? grip : ctrl->keygrip, &s_skey, &keymeta, NULL);
+  err = read_key_file (ctrl, grip? grip : ctrl->keygrip,
+                       &s_skey, &keymeta, NULL);
   if (err)
     {
       if (gpg_err_code (err) == GPG_ERR_ENOENT)
@@ -1485,7 +1644,7 @@ agent_raw_key_from_file (ctrl_t ctrl, const unsigned char *grip,
 
   *result = NULL;
 
-  err = read_key_file (grip, &s_skey, r_keymeta, NULL);
+  err = read_key_file (ctrl, grip, &s_skey, r_keymeta, NULL);
   if (!err)
     *result = s_skey;
   return err;
@@ -1528,7 +1687,7 @@ public_key_from_file (ctrl_t ctrl, const unsigned char *grip,
   if (r_sshorder)
     *r_sshorder = 0;
 
-  err = read_key_file (grip, &s_skey, for_ssh? &keymeta : NULL, NULL);
+  err = read_key_file (ctrl, grip, &s_skey, for_ssh? &keymeta : NULL, NULL);
   if (err)
     return err;
 
@@ -1656,13 +1815,23 @@ agent_ssh_key_from_file (ctrl_t ctrl,
 
 
 /* Check whether the secret key identified by GRIP is available.
-   Returns 0 is the key is available.  */
+   Returns 0 is the key is available. */
 int
-agent_key_available (const unsigned char *grip)
+agent_key_available (ctrl_t ctrl, const unsigned char *grip)
 {
   int result;
   char *fname;
   char hexgrip[40+4+1];
+  ephemeral_private_key_t ek;
+
+  if (ctrl && ctrl->ephemeral_mode)
+    {
+      for (ek = ctrl->ephemeral_keys; ek; ek = ek->next)
+        if (!memcmp (ek->grip, grip, KEYGRIP_LEN)
+            && ek->keybuf && ek->keybuflen)
+          return 0;
+      return -1;
+    }
 
   bin2hex (grip, 20, hexgrip);
   strcpy (hexgrip+40, ".key");
@@ -1675,7 +1844,6 @@ agent_key_available (const unsigned char *grip)
 }
 
 
-
 /* Return the information about the secret key specified by the binary
    keygrip GRIP.  If the key is a shadowed one the shadow information
    will be stored at the address R_SHADOW_INFO as an allocated
@@ -1700,7 +1868,7 @@ agent_key_info_from_file (ctrl_t ctrl, const unsigned char *grip,
   {
     gcry_sexp_t sexp;
 
-    err = read_key_file (grip, &sexp, NULL, NULL);
+    err = read_key_file (ctrl, grip, &sexp, NULL, NULL);
     if (err)
       {
         if (gpg_err_code (err) == GPG_ERR_ENOENT)
@@ -1784,7 +1952,13 @@ agent_delete_key (ctrl_t ctrl, const char *desc_text,
   char *default_desc = NULL;
   int key_type;
 
-  err = read_key_file (grip, &s_skey, NULL, NULL);
+  if (ctrl->ephemeral_mode)
+    {
+      err = gpg_error (GPG_ERR_NO_SECKEY);
+      goto leave;
+    }
+
+  err = read_key_file (ctrl, grip, &s_skey, NULL, NULL);
   if (gpg_err_code (err) == GPG_ERR_ENOENT)
     err = gpg_error (GPG_ERR_NO_SECKEY);
   if (err)
@@ -1885,7 +2059,7 @@ agent_delete_key (ctrl_t ctrl, const char *desc_text,
    card's SERIALNO and the IDSTRING.  With FORCE passed as true an
    existing key with the given GRIP will get overwritten.  */
 gpg_error_t
-agent_write_shadow_key (const unsigned char *grip,
+agent_write_shadow_key (ctrl_t ctrl, const unsigned char *grip,
                         const char *serialno, const char *keyid,
                         const unsigned char *pkbuf, int force,
                         const char *dispserialno)
@@ -1915,7 +2089,7 @@ agent_write_shadow_key (const unsigned char *grip,
     }
 
   len = gcry_sexp_canon_len (shdkey, 0, NULL, NULL);
-  err = agent_write_private_key (grip, shdkey, len, force,
+  err = agent_write_private_key (ctrl, grip, shdkey, len, force,
                                  serialno, keyid, dispserialno, 0);
   xfree (shdkey);
   if (err)
diff --git a/agent/genkey.c b/agent/genkey.c
index 741c05f4f..444f89f79 100644
--- a/agent/genkey.c
+++ b/agent/genkey.c
@@ -30,14 +30,36 @@
 #include "../common/exechelp.h"
 #include "../common/sysutils.h"
 
-static int
-store_key (gcry_sexp_t private, const char *passphrase, int force,
+
+void
+clear_ephemeral_keys (ctrl_t ctrl)
+{
+  while (ctrl->ephemeral_keys)
+    {
+      ephemeral_private_key_t next = ctrl->ephemeral_keys->next;
+      if (ctrl->ephemeral_keys->keybuf)
+        {
+          wipememory (ctrl->ephemeral_keys->keybuf,
+                      ctrl->ephemeral_keys->keybuflen);
+          xfree (ctrl->ephemeral_keys->keybuf);
+        }
+      xfree (ctrl->ephemeral_keys);
+      ctrl->ephemeral_keys = next;
+    }
+}
+
+
+/* Store the key either to a file, or in ctrl->ephemeral_mode in the
+ * session data.  */
+static gpg_error_t
+store_key (ctrl_t ctrl, gcry_sexp_t private,
+           const char *passphrase, int force,
            unsigned long s2k_count, time_t timestamp)
 {
-  int rc;
+  gpg_error_t err;
   unsigned char *buf;
   size_t len;
-  unsigned char grip[20];
+  unsigned char grip[KEYGRIP_LEN];
 
   if ( !gcry_pk_get_keygrip (private, grip) )
     {
@@ -49,7 +71,10 @@ store_key (gcry_sexp_t private, const char *passphrase, int force,
   log_assert (len);
   buf = gcry_malloc_secure (len);
   if (!buf)
-      return out_of_core ();
+    {
+      err = gpg_error_from_syserror ();
+      goto leave;
+    }
   len = gcry_sexp_sprint (private, GCRYSEXP_FMT_CANON, buf, len);
   log_assert (len);
 
@@ -57,20 +82,56 @@ store_key (gcry_sexp_t private, const char *passphrase, int force,
     {
       unsigned char *p;
 
-      rc = agent_protect (buf, passphrase, &p, &len, s2k_count);
-      if (rc)
-        {
-          xfree (buf);
-          return rc;
-        }
+      err = agent_protect (buf, passphrase, &p, &len, s2k_count);
+      if (err)
+        goto leave;
       xfree (buf);
       buf = p;
     }
 
-  rc = agent_write_private_key (grip, buf, len, force,
-                                NULL, NULL, NULL, timestamp);
+  if (ctrl->ephemeral_mode)
+    {
+      ephemeral_private_key_t ek;
+
+      for (ek = ctrl->ephemeral_keys; ek; ek = ek->next)
+        if (!memcmp (ek->grip, grip, KEYGRIP_LEN))
+          break;
+      if (!ek)
+        {
+          ek = xtrycalloc (1, sizeof *ek);
+          if (!ek)
+            {
+              err = gpg_error_from_syserror ();
+              goto leave;
+            }
+          memcpy (ek->grip, grip, KEYGRIP_LEN);
+          ek->next = ctrl->ephemeral_keys;
+          ctrl->ephemeral_keys = ek;
+        }
+      if (ek->keybuf)
+        {
+          wipememory (ek->keybuf, ek->keybuflen);
+          xfree (ek->keybuf);
+        }
+      ek->keybuf = buf;
+      buf = NULL;
+      ek->keybuflen = len;
+    }
+  else
+    err = agent_write_private_key (ctrl, grip, buf, len, force,
+                                   NULL, NULL, NULL, timestamp);
+
+  if (!err)
+    {
+      char hexgrip[2*KEYGRIP_LEN+1];
+
+      bin2hex (grip, KEYGRIP_LEN, hexgrip);
+      agent_write_status (ctrl, "KEYGRIP", hexgrip, NULL);
+    }
+
+ leave:
   xfree (buf);
-  return rc;
+  return err;
 }
 
 
@@ -450,16 +511,19 @@ agent_ask_new_passphrase (ctrl_t ctrl, const char *prompt,
 
 
 /* Generate a new keypair according to the parameters given in
-   KEYPARAM.  If CACHE_NONCE is given first try to lookup a passphrase
-   using the cache nonce.  If NO_PROTECTION is true the key will not
-   be protected by a passphrase.  If OVERRIDE_PASSPHRASE is true that
-   passphrase will be used for the new key.  If TIMESTAMP is not zero
-   it will be recorded as creation date of the key (unless extended
-   format is disabled) . */
+ * KEYPARAM.  If CACHE_NONCE is given first try to lookup a passphrase
+ * using the cache nonce.  If NO_PROTECTION is true the key will not
+ * be protected by a passphrase.  If OVERRIDE_PASSPHRASE is true that
+ * passphrase will be used for the new key.  If TIMESTAMP is not zero
+ * it will be recorded as creation date of the key (unless extended
+ * format is disabled).  In ctrl_ephemeral_mode the key is stored in
+ * the session data and an identifier is returned using a status
+ * line.  */
 int
-agent_genkey (ctrl_t ctrl, const char *cache_nonce, time_t timestamp,
-              const char *keyparam, size_t keyparamlen, int no_protection,
-              const char *override_passphrase, int preset, membuf_t *outbuf)
+agent_genkey (ctrl_t ctrl, unsigned int flags,
+              const char *cache_nonce, time_t timestamp,
+              const char *keyparam, size_t keyparamlen,
+              const char *override_passphrase, membuf_t *outbuf)
 {
   gcry_sexp_t s_keyparam, s_key, s_private, s_public;
   char *passphrase_buffer = NULL;
@@ -478,7 +542,7 @@ agent_genkey (ctrl_t ctrl, const char *cache_nonce, time_t timestamp,
   /* Get the passphrase now, cause key generation may take a while. */
   if (override_passphrase)
     passphrase = override_passphrase;
-  else if (no_protection || !cache_nonce)
+  else if ((flags & GENKEY_FLAG_NO_PROTECTION) || !cache_nonce)
     passphrase = NULL;
   else
     {
@@ -486,8 +550,8 @@ agent_genkey (ctrl_t ctrl, const char *cache_nonce, time_t timestamp,
       passphrase = passphrase_buffer;
     }
 
-  if (passphrase || no_protection)
-    ;
+  if (passphrase || (flags & GENKEY_FLAG_NO_PROTECTION))
+    ; /* No need to ask for a passphrase.  */
   else
     {
       rc = agent_ask_new_passphrase (ctrl,
@@ -532,11 +596,14 @@ agent_genkey (ctrl_t ctrl, const char *cache_nonce, time_t timestamp,
   gcry_sexp_release (s_key); s_key = NULL;
 
   /* store the secret key */
-  if (DBG_CRYPTO)
-    log_debug ("storing private key\n");
-  rc = store_key (s_private, passphrase, 0, ctrl->s2k_count, timestamp);
-  if (!rc)
+  if (opt.verbose)
+    log_info ("storing %sprivate key\n",
+               ctrl->ephemeral_mode?"ephemeral ":"");
+  rc = store_key (ctrl, s_private, passphrase, 0, ctrl->s2k_count, timestamp);
+  if (!rc && !ctrl->ephemeral_mode)
     {
+      /* FIXME: or does it make sense to also cache passphrases in
+       * ephemeral mode using a dedicated cache?  */
       if (!cache_nonce)
         {
           char tmpbuf[12];
@@ -544,21 +611,23 @@ agent_genkey (ctrl_t ctrl, const char *cache_nonce, time_t timestamp,
           cache_nonce = bin2hex (tmpbuf, 12, NULL);
         }
       if (cache_nonce
-          && !no_protection
+          && !(flags & GENKEY_FLAG_NO_PROTECTION)
           && !agent_put_cache (ctrl, cache_nonce, CACHE_MODE_NONCE,
                                passphrase, ctrl->cache_ttl_opt_preset))
         agent_write_status (ctrl, "CACHE_NONCE", cache_nonce, NULL);
-      if (preset && !no_protection)
-	{
-	  unsigned char grip[20];
-	  char hexgrip[40+1];
-	  if (gcry_pk_get_keygrip (s_private, grip))
-	    {
-	      bin2hex(grip, 20, hexgrip);
-	      rc = agent_put_cache (ctrl, hexgrip, CACHE_MODE_ANY, passphrase,
+      if ((flags & GENKEY_FLAG_PRESET)
+          && !(flags & GENKEY_FLAG_NO_PROTECTION))
+        {
+          unsigned char grip[20];
+          char hexgrip[40+1];
+          if (gcry_pk_get_keygrip (s_private, grip))
+            {
+              bin2hex(grip, 20, hexgrip);
+              rc = agent_put_cache (ctrl, hexgrip,
+                                    CACHE_MODE_ANY, passphrase,
                                     ctrl->cache_ttl_opt_preset);
-	    }
-	}
+            }
+        }
     }
   xfree (passphrase_buffer);
   passphrase_buffer = NULL;
@@ -607,7 +676,8 @@ agent_protect_and_store (ctrl_t ctrl, gcry_sexp_t s_skey,
   if (passphrase_addr && *passphrase_addr)
     {
       /* Take an empty string as request not to protect the key.  */
-      err = store_key (s_skey, **passphrase_addr? *passphrase_addr:NULL, 1,
+      err = store_key (ctrl, s_skey,
+                       **passphrase_addr? *passphrase_addr:NULL, 1,
                        ctrl->s2k_count, 0);
     }
   else
@@ -623,7 +693,7 @@ agent_protect_and_store (ctrl_t ctrl, gcry_sexp_t s_skey,
                                       L_("Please enter the new passphrase"),
                                       &pass);
       if (!err)
-        err = store_key (s_skey, pass, 1, ctrl->s2k_count, 0);
+        err = store_key (ctrl, s_skey, pass, 1, ctrl->s2k_count, 0);
       if (!err && passphrase_addr)
         *passphrase_addr = pass;
       else
diff --git a/agent/gpg-agent.c b/agent/gpg-agent.c
index b0150031d..a5448ac38 100644
--- a/agent/gpg-agent.c
+++ b/agent/gpg-agent.c
@@ -1989,6 +1989,7 @@ agent_deinit_default_ctrl (ctrl_t ctrl)
 {
   unregister_progress_cb ();
   session_env_release (ctrl->session_env);
+  clear_ephemeral_keys (ctrl);
 
   xfree (ctrl->digest.data);
   ctrl->digest.data = NULL;
diff --git a/agent/learncard.c b/agent/learncard.c
index 8d80b809d..83945b8be 100644
--- a/agent/learncard.c
+++ b/agent/learncard.c
@@ -397,7 +397,7 @@ agent_handle_learn (ctrl_t ctrl, int send, void *assuan_context, int force)
       for (p=item->hexgrip, i=0; i < 20; p += 2, i++)
         grip[i] = xtoi_2 (p);
 
-      if (!force && !agent_key_available (grip))
+      if (!force && !agent_key_available (ctrl, grip))
         continue; /* The key is already available. */
 
       /* Unknown key - store it. */
@@ -408,15 +408,17 @@ agent_handle_learn (ctrl_t ctrl, int send, void *assuan_context, int force)
           goto leave;
         }
 
-      {
-        char *dispserialno;
-
-        agent_card_getattr (ctrl, "$DISPSERIALNO", &dispserialno,
-                            item->hexgrip);
-        rc = agent_write_shadow_key (grip, serialno, item->id, pubkey, force,
-                                     dispserialno);
-        xfree (dispserialno);
-      }
+      if (!ctrl->ephemeral_mode)
+        {
+          char *dispserialno;
+
+          agent_card_getattr (ctrl, "$DISPSERIALNO", &dispserialno,
+                              item->hexgrip);
+          rc = agent_write_shadow_key (ctrl,
+                                       grip, serialno, item->id, pubkey, force,
+                                       dispserialno);
+          xfree (dispserialno);
+        }
       xfree (pubkey);
       if (rc)
         goto leave;
diff --git a/agent/pksign.c b/agent/pksign.c
index a7b5c579f..322918969 100644
--- a/agent/pksign.c
+++ b/agent/pksign.c
@@ -371,13 +371,14 @@ agent_pksign_do (ctrl_t ctrl, const char *cache_nonce,
               goto leave;
             }
 
-          if (keyref)
+          if (keyref && !ctrl->ephemeral_mode)
             {
               char *dispserialno;
 
               agent_card_getattr (ctrl, "$DISPSERIALNO", &dispserialno,
                                   hexgrip);
-              agent_write_shadow_key (ctrl->keygrip, serialno, keyref, pkbuf,
+              agent_write_shadow_key (ctrl,
+                                      ctrl->keygrip, serialno, keyref, pkbuf,
                                       0, dispserialno);
               xfree (dispserialno);
             }
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;