--- /dev/null
+#!/usr/bin/python
+from k5test import *
+
+rollover_krb5_conf = {'all' : {'libdefaults' : {'allow_weak_crypto' : 'true'}}}
+
+realm = K5Realm(krbtgt_keysalt='des-cbc-crc:normal',
+ krb5_conf=rollover_krb5_conf)
+
+princ1 = 'host/test1@%s' % (realm.realm,)
+princ2 = 'host/test2@%s' % (realm.realm,)
+realm.addprinc(princ1)
+realm.addprinc(princ2)
+
+realm.run_as_client([kvno, realm.host_princ])
+
+# Change key for TGS, keeping old key.
+realm.run_kadminl('cpw -randkey -e aes256-cts:normal -keepold krbtgt/%s@%s' %
+ (realm.realm, realm.realm))
+
+# Ensure that kvno still works with an old TGT.
+realm.run_as_client([kvno, princ1])
+
+realm.run_kadminl('purgekeys krbtgt/%s@%s' % (realm.realm, realm.realm))
+# Make sure an old TGT fails after purging old TGS key.
+realm.run_as_client([kvno, princ2], expected_code=1)
+output = realm.run_as_client([klist, '-e'])
+
+expected = 'krbtgt/%s@%s\n\tEtype (skey, tkt): des-cbc-crc, des-cbc-crc' % \
+ (realm.realm, realm.realm)
+
+if expected not in output:
+ fail('keyrollover: expected TGS enctype not found')
+
+# Check that new key actually works.
+realm.kinit(realm.user_princ, password('user'))
+realm.run_as_client([kvno, realm.host_princ])
+output = realm.run_as_client([klist, '-e'])
+
+expected = 'krbtgt/%s@%s\n\tEtype (skey, tkt): ' \
+ 'aes256-cts-hmac-sha1-96, aes256-cts-hmac-sha1-96' % \
+ (realm.realm, realm.realm)
+
+if expected not in output:
+ fail('keyrollover: expected TGS enctype not found after change')
+
+success('keyrollover')