agent: Support pinentries with integrated repeat passphrase feature.

* agent/agent.h (struct pin_entry_info_s): Add fields repeat_okay and
with_repeat.
* agent/call-pinentry.c (close_button_status_cb): Rewrite and check
for PIN_REPEAT.  Change users to check only the relevant bit.
(agent_askpin): Support repeat logic of new Pinentries.

* agent/command-ssh.c (ssh_identity_register): Use the new repeat
feature.
* agent/genkey.c (agent_ask_new_passphrase): Ditto.

--

If we need to confirm a passphrase entry (e.g. for new passphrase) we
set a flag into the pinentry info block.  The we try to use the new
pinentry command SETREPEATERROR; if that fails, we continue as usual.
If that succeeds we ask the pinentry to show the repeat (confirmation)
prompt and on successful return we set another flag in the pinentry
info block so that the caller can skip its own confirmation check. A
new status line from the pinentry indicates that the feature is
actually supported (it may not be supported on certain systems for
example when using the ncurses backend).

Signed-off-by: Werner Koch <[email protected]>

1 files changed, 42 insertions, 15 deletions

diff --git a/agent/call-pinentry.c b/agent/call-pinentry.c
index 126d6968b..e5977ad6a 100644
--- a/agent/call-pinentry.c
+++ b/agent/call-pinentry.c
@@ -682,23 +682,23 @@ setup_qualitybar (void)
 }
 
 
-/* Check the button_info line for a close action.  */
+/* Check the button_info line for a close action.  Also check for the
+   PIN_REPEATED flag.  */
 static gpg_error_t
 close_button_status_cb (void *opaque, const char *line)
 {
-  int *flag = opaque;
-  const char *keyword = line;
-  int keywordlen;
+  unsigned int *flag = opaque;
+  const char *args;
 
-  for (keywordlen=0; *line && !spacep (line); line++, keywordlen++)
-    ;
-  while (spacep (line))
-    line++;
-  if (keywordlen == 11 && !memcmp (keyword, "BUTTON_INFO", keywordlen))
+  if ((args = has_leading_keyword (line, "BUTTON_INFO")))
     {
-      if ( !strcmp (line, "close") )
+      if (!strcmp (args, "close"))
         *flag = 1;
     }
+  else if (has_leading_keyword (line, "PIN_REPEATED"))
+    {
+      *flag |= 256;
+    }
 
   return 0;
 }
@@ -721,7 +721,7 @@ agent_askpin (ctrl_t ctrl,
   const char *errtext = NULL;
   int is_pin = 0;
   int saveflag;
-  int close_button;
+  unsigned int close_button;
 
   if (opt.batch)
     return 0; /* fixme: we should return BAD PIN */
@@ -806,6 +806,18 @@ agent_askpin (ctrl_t ctrl,
         return unlock_pinentry (rc);
     }
 
+  if (pininfo->with_repeat)
+    {
+      snprintf (line, DIM(line)-1, "SETREPEATERROR %s",
+                _("does not match - try again"));
+      line[DIM(line)-1] = 0;
+      rc = assuan_transact (entry_ctx, line,
+                            NULL, NULL, NULL, NULL, NULL, NULL);
+      if (rc)
+        pininfo->with_repeat = 0; /* Pinentry does not support it.  */
+    }
+  pininfo->repeat_okay = 0;
+
   for (;pininfo->failed_tries < pininfo->max_tries; pininfo->failed_tries++)
     {
       memset (&parm, 0, sizeof parm);
@@ -828,6 +840,16 @@ agent_askpin (ctrl_t ctrl,
           errtext = NULL;
         }
 
+      if (pininfo->with_repeat)
+        {
+          snprintf (line, DIM(line)-1, "SETREPEAT %s", _("Repeat:"));
+          line[DIM(line)-1] = 0;
+          rc = assuan_transact (entry_ctx, line,
+                                NULL, NULL, NULL, NULL, NULL, NULL);
+          if (rc)
+            return unlock_pinentry (rc);
+        }
+
       saveflag = assuan_get_flag (entry_ctx, ASSUAN_CONFIDENTIAL);
       assuan_begin_confidential (entry_ctx);
       close_button = 0;
@@ -842,9 +864,10 @@ agent_askpin (ctrl_t ctrl,
           && gpg_err_code (rc) == GPG_ERR_ASS_CANCELED)
         rc = gpg_err_make (gpg_err_source (rc), GPG_ERR_CANCELED);
 
+
       /* Change error code in case the window close button was clicked
          to cancel the operation.  */
-      if (close_button && gpg_err_code (rc) == GPG_ERR_CANCELED)
+      if ((close_button & 1) && gpg_err_code (rc) == GPG_ERR_CANCELED)
         rc = gpg_err_make (gpg_err_source (rc), GPG_ERR_FULLY_CANCELED);
 
       if (gpg_err_code (rc) == GPG_ERR_ASS_TOO_MUCH_DATA)
@@ -881,7 +904,11 @@ agent_askpin (ctrl_t ctrl,
         }
 
       if (!errtext)
-        return unlock_pinentry (0); /* okay, got a PIN or passphrase */
+        {
+          if (pininfo->with_repeat && (close_button & 256))
+            pininfo->repeat_okay = 1;
+          return unlock_pinentry (0); /* okay, got a PIN or passphrase */
+        }
     }
 
   return unlock_pinentry (gpg_error (pininfo->min_digits? GPG_ERR_BAD_PIN
@@ -902,7 +929,7 @@ agent_get_passphrase (ctrl_t ctrl,
   char line[ASSUAN_LINELENGTH];
   struct entry_parm_s parm;
   int saveflag;
-  int close_button;
+  unsigned int close_button;
 
   *retpass = NULL;
   if (opt.batch)
@@ -991,7 +1018,7 @@ agent_get_passphrase (ctrl_t ctrl,
     rc = gpg_err_make (gpg_err_source (rc), GPG_ERR_CANCELED);
   /* Change error code in case the window close button was clicked
      to cancel the operation.  */
-  if (close_button && gpg_err_code (rc) == GPG_ERR_CANCELED)
+  if ((close_button & 1) && gpg_err_code (rc) == GPG_ERR_CANCELED)
     rc = gpg_err_make (gpg_err_source (rc), GPG_ERR_FULLY_CANCELED);
 
   if (rc)