[krbdev.mit.edu #6049] krb5_ktfile_get_entry() not dealing with enctype arg properly

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Date: Wed, 23 Jul 2008 16:33:44 -0500
From: Will Fiveash <William.Fiveash at Sun.COM>
To: krb5-bugs at mit.edu
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>Submitter-Id:	net
>Originator:	William Fiveash
>Organization:
	Sun Microsystems
>Confidential:	no 
>Synopsis:	krb5_ktfile_get_entry() not dealing with enctype arg properly 
>Severity:	serious 
>Priority:	medium 
>Category:	krb5-libs 
>Class:		sw-bug 
>Release:	krb5-1.6.3
>Environment:
	
System: SunOS alton 5.11 snv_88 i86pc i386 i86pc
Architecture: i86pc

>Description:
	
In krb5_ktfile_get_entry() there is this code:

    /* if the enctype is not ignored and doesn't match, free new_entry
       and continue to the next */

    if (enctype != IGNORE_ENCTYPE) {
        if ((kerror = krb5_c_enctype_compare(context, enctype, 
                         new_entry.key.enctype,
                         &similar))) {
        krb5_kt_free_entry(context, &new_entry);
        break;
        }

Seems to me the break; should actually be continue; in the case that the
keytab has an entry with an unknown enctype.

A refinement to this would be to verify that the enctype input arg is a
valid enctype early on.

>How-To-Repeat:
	

Create a keytab with an unsupported enctype followed by a supported
enctype then try to get a key with the supported enctype.

>Fix:
	
--- ./lib/krb5/keytab/kt_file.c Wed Jul 23 13:35:30 2008
+++ /tmp/kt_file.c      Wed Jul 23 16:08:47 2008
@@ -333,7 +333,7 @@
                                                 new_entry.key.enctype,
                                                 &similar))) {
                krb5_kt_free_entry(context, &new_entry);
-               break;
+               continue;
            }
 
            if (!similar) {