kerberos/gss enhancements

add a parameter *datalen to decrypt_krb5_data() so that we can pass back 
the length of the decrypted blob back to the caller.
This is useful for when there are "junk" at the end of the blob and thus 
the decrypted data is not the same size as the encrypted blob.
GSS CFX is one such example.
(we should have done this earlier since it might have made some other 
stuff easier to imlement...)


make the preference setting krb_decrypt a globally visible variable so 
we can see its value and act on it from callers of krb decryption from 
outside of packet-kerberos.c    i.e.   from GSS CFX


Make keytype == -1  a wildcard that when passed to decrypt_krb5_data() 
will try any/all encryption keys.
This since GSS CFX does not provide the enctype in the GSS layer.
(The GSS CFX enctype is only negotiated during the AP-REQ/REP  so we 
should later pick this value up and store it in a CFX session variable.
That is for a later enhancement.
)


Enhance the GSS decryption (that for hitorical reasons are implemented 
in packet-spnego.c  and not packet-gssapi.c :-)  )
to also handle decryption of GSS CFX

This should make wireshark able to decrypt any/all GSSAPI  RFC4121 
packets, if the keytab file is provided.


I have successfully decrypted LDAP using GSS CFX with AES encryption 
with this.




svn path=/trunk/; revision=26350

1 files changed, 4 insertions, 1 deletions

diff --git a/epan/dissectors/packet-kerberos.h b/epan/dissectors/packet-kerberos.h
index 748971a5b7..c9607bd7a6 100644
--- a/epan/dissectors/packet-kerberos.h
+++ b/epan/dissectors/packet-kerberos.h
@@ -79,10 +79,13 @@ decrypt_krb5_data(proto_tree *tree, packet_info *pinfo,
 			int usage,
 			int length,
 			const guint8 *cryptotext,
-			int keytype);
+			int keytype,
+			int *datalen);
 
 #endif /* HAVE_HEIMDAL_KERBEROS || HAVE_MIT_KERBEROS */
 
+extern gboolean krb_decrypt;
+
 #endif /* HAVE_KERBEROS */
 
 #endif /* __PACKET_KERBEROS_H */