krb5 commit: Log unknown enctypes as unsupported in KDC

https://github.com/krb5/krb5/commit/5ee99b0007f480f01f86340d1c30da51cc80da96
commit 5ee99b0007f480f01f86340d1c30da51cc80da96
Author: Greg Hudson <[email protected]>
Date:   Fri Sep 27 16:55:37 2019 -0400

    Log unknown enctypes as unsupported in KDC
    
    Commit 8d8e68283b599e680f9fe45eff8af397e827bd6c logs both invalid and
    deprecated enctypes as "DEPRECATED:".  An invalid enctype might be too
    old or marginal to be supported (like single-DES) or too new to be
    recognized.  For clarity, prefix invalid enctypes with "UNSUPPORTED:"
    instead.
    
    ticket: 8773

 src/kdc/kdc_util.c |   18 ++++++++++--------
 1 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/kdc/kdc_util.c b/src/kdc/kdc_util.c
index 8c0fa8c..1982334 100644
--- a/src/kdc/kdc_util.c
+++ b/src/kdc/kdc_util.c
@@ -1073,20 +1073,22 @@ void limit_string(char *name)
 static krb5_error_code
 enctype_name(krb5_enctype ktype, char *buf, size_t buflen)
 {
-    char *name;
+    const char *name, *prefix = "";
     size_t len;
 
     if (buflen == 0)
         return EINVAL;
     *buf = '\0'; /* ensure these are always valid C-strings */
 
-    if (krb5int_c_deprecated_enctype(ktype)) {
-        len = strlcpy(buf, "DEPRECATED:", buflen);
-        if (len >= buflen)
-            return ENOMEM;
-        buflen -= len;
-        buf += len;
-    }
+    if (!krb5_c_valid_enctype(ktype))
+        prefix = "UNSUPPORTED:";
+    else if (krb5int_c_deprecated_enctype(ktype))
+        prefix = "DEPRECATED:";
+    len = strlcpy(buf, prefix, buflen);
+    if (len >= buflen)
+        return ENOMEM;
+    buflen -= len;
+    buf += len;
 
     /* rfc4556 recommends that clients wishing to indicate support for these
      * pkinit algorithms include them in the etype field of the AS-REQ. */