upstream: translate and return error codes; retry on bad PIN

Define some well-known error codes in the SK API and pass
them back via ssh-sk-helper.

Use the new "wrong PIN" error code to retry PIN prompting during
ssh-keygen of resident keys.

feedback and ok markus@

OpenBSD-Commit-ID: 9663c6a2bb7a0bc8deaccc6c30d9a2983b481620

1 files changed, 3 insertions, 1 deletions

diff --git a/ssherr.c b/ssherr.c
index 8ad3d5750..38974f51b 100644
--- a/ssherr.c
+++ b/ssherr.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: ssherr.c,v 1.8 2018/07/03 11:39:54 djm Exp $  */
+/*      $OpenBSD: ssherr.c,v 1.9 2019/12/30 09:24:45 djm Exp $  */
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -141,6 +141,8 @@ ssh_err(int n)
                 return "number is too large";
         case SSH_ERR_SIGN_ALG_UNSUPPORTED:
                 return "signature algorithm not supported";
+        case SSH_ERR_FEATURE_UNSUPPORTED:
+                return "requested feature not supported";
         default:
                 return "unknown error";
         }