title: GSS-API Java strange error
body: <p>I'm running the following tutorial:
  <a href="http://download.oracle.com/javase/6/docs/technotes/guides/security/jgss/tutorials/BasicClientServer.html" rel="nofollow">http://download.oracle.com/javase/6/docs/technotes/guides/security/jgss/tutorials/BasicClientServer.html</a></p>
  
  <p>I'm getting the following prompts:</p>
  
  <pre><code>Connected to server localhost/127.0.0.1
  Kerberos username [login]: {I enter my username here}
  Kerberos password for login: {I enter my password here}
  </code></pre>
  
  <p>I get the following error:</p>
  
  <p>Can you ascertain the root cause of this?</p>
  
  <pre><code>Exception in thread "main" GSSException: No valid credentials provided (Mechanism level: Attempt to obtain new INITIATE credentials failed! (null))
  at sun.security.jgss.krb5.Krb5InitCredential.getTgt(Krb5InitCredential.java:333)
  at sun.security.jgss.krb5.Krb5InitCredential.getInstance(Krb5InitCredential.java:128)
  at sun.security.jgss.krb5.Krb5MechFactory.getCredentialElement(Krb5MechFactory.java:106)
  at sun.security.jgss.krb5.Krb5MechFactory.getMechanismContext(Krb5MechFactory.java:172)
  at sun.security.jgss.GSSManagerImpl.getMechanismContext(GSSManagerImpl.java:209)
  at sun.security.jgss.GSSContextImpl.initSecContext(GSSContextImpl.java:195)
  at sun.security.jgss.GSSContextImpl.initSecContext(GSSContextImpl.java:162)
  at demo.SampleClient.main(SampleClient.java:145)
  Caused by: javax.security.auth.login.LoginException: Message stream modified (41)
  at com.sun.security.auth.module.Krb5LoginModule.attemptAuthentication(Krb5LoginModule.java:696)
  at com.sun.security.auth.module.Krb5LoginModule.login(Krb5LoginModule.java:542)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at javax.security.auth.login.LoginContext.invoke(LoginContext.java:769)
  at javax.security.auth.login.LoginContext.access$000(LoginContext.java:186)
  at javax.security.auth.login.LoginContext$5.run(LoginContext.java:706)
  at java.security.AccessController.doPrivileged(Native Method)
  at javax.security.auth.login.LoginContext.invokeCreatorPriv(LoginContext.java:703)
  at javax.security.auth.login.LoginContext.login(LoginContext.java:575)
  at sun.security.jgss.GSSUtil.login(GSSUtil.java:246)
  at sun.security.jgss.krb5.Krb5Util.getTicket(Krb5Util.java:136)
  at sun.security.jgss.krb5.Krb5InitCredential$1.run(Krb5InitCredential.java:328)
  at java.security.AccessController.doPrivileged(Native Method)
  at sun.security.jgss.krb5.Krb5InitCredential.getTgt(Krb5InitCredential.java:325)
  ... 7 more
  Caused by: KrbException: Message stream modified (41)
  at sun.security.krb5.KrbKdcRep.check(KrbKdcRep.java:53)
  at sun.security.krb5.KrbAsRep.&lt;init&gt;(KrbAsRep.java:96)
  at sun.security.krb5.KrbAsReq.getReply(KrbAsReq.java:449)
  at sun.security.krb5.Credentials.sendASRequest(Credentials.java:410)
  at sun.security.krb5.Credentials.acquireTGT(Credentials.java:378)
  at com.sun.security.auth.module.Krb5LoginModule.attemptAuthentication(Krb5LoginModule.java:662)
  ... 23 more
  </code></pre>