From 4168cfe85d2a99c4b0f3eeef889f3bef637cd5e2 Mon Sep 17 00:00:00 2001
From: Mats Erik Andersson <gnu@gisladisker.se>
Date: Fri, 17 Aug 2012 03:29:15 +0200
Subject: [PATCH] telnet: Activate principal naming.

---
 ChangeLog          | 10 ++++++++++
 libtelnet/shishi.c |  8 +++++++-
 telnet/commands.c  | 14 +++++++++++++-
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 356d739f..d25bdb49 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2012-08-17  Mats Erik Andersson  <gnu@gisladisker.se>
+
+	telnet: Selectable principal name.
+
+	* libtelnet/shishi.c (krb5shishi_send): Add a prefix
+	`host/' to RemoteHostName only if a prefix is missing.
+	* telnet/commands.c (tn) [AUTHENTICATION || ENCRYPTION]:
+	Strip off any prefix from HOSTP before resolving address.
+	[IPV6]: Improve error message at failed resolution.
+
 2012-08-16  Mats Erik Andersson  <gnu@gisladisker.se>
 
 	telnetd: Configurable principal name.
diff --git a/libtelnet/shishi.c b/libtelnet/shishi.c
index 1a21624e..0ffd6a98 100644
--- a/libtelnet/shishi.c
+++ b/libtelnet/shishi.c
@@ -173,7 +173,13 @@ krb5shishi_send (TN_Authenticator * ap)
       DEBUG (("telnet: Kerberos V5: shishi memory allocation failed\r\n"));
       return 0;
     }
-  sprintf (tmp, "host/%s", RemoteHostName);
+
+  /* Check for Kerberos prefix in principal name.  */
+  if (strchr (RemoteHostName, '/'))
+    strcpy (tmp, RemoteHostName);
+  else
+    sprintf (tmp, "host/%s", RemoteHostName);
+
   memset (&hint, 0, sizeof (hint));
   hint.server = tmp;
   hint.client = UserNameRequested;
diff --git a/telnet/commands.c b/telnet/commands.c
index 6a1be367..b511e4ce 100644
--- a/telnet/commands.c
+++ b/telnet/commands.c
@@ -2555,6 +2555,18 @@ tn (int argc, char *argv[])
       return 0;
     }
 
+#if defined AUTHENTICATION || defined ENCRYPTION
+  {
+    /* Extract instance name of server, eliminating
+     * the Kerberos principal prefix.
+     */
+    char *p = strchr (hostp, '/');
+
+    if (p)
+      hostp = ++p;
+  }
+#endif /* AUTHENTICATION || ENCRYPTION */
+
 #ifdef IPV6
   hints.ai_socktype = SOCK_STREAM;
 
@@ -2568,7 +2580,7 @@ tn (int argc, char *argv[])
       else
 	errmsg = gai_strerror (err);
 
-      printf ("%s/%s: lookup failure: %s\n", hostp, portp, errmsg);
+      printf ("Server lookup failure:  %s:%s, %s\n", hostp, portp, errmsg);
       return 0;
     }