SPNEGO troubleshooting tips


 

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  1. Microsoft Security patch 974455
  2. Unable to resolve the Kerberos principal name
  3. WAS and the time on the Active Directory domain controller are not synchronized within 5 minutes
  4. No factory is available to create name for mechanism 1.3.6.1.5.5.2
  5. A Kerberos error is received while decoding and verifying the SPNEGO token
  6. Single sign-on does not occur
  7. Unable to use sign-on with RC4-HMAC encryption
  8. Problems when accessing a protected URL through the SPNEGO single sign-on
  9. Even with JGSS tracing disabled, some KRB_DBG_KDC messages appear in the SystemOut.log
  10. ktpass is unable to find the userid
  11. Credential delegation might not work due to an invalid option in the ticket request
  12. A user is challenged for credentials even though the browser is properly configured
  13. A user using the Novell client cannot authenticate using SPNEGO
  14. Accessing SPNEGO sites via some caching proxy servers can cause SPNEGO authentication issues
  15. VPN software and firewalls might interfere with SPNEGO operations
  16. Possible browser issue when accessing a SPNEGO protected application
  17. Error pages defined for the NTLMTokenReceivedPage or the SpnegoNotSupportedPage properties do load from an http:// URL

 

 

Microsoft Security patch 974455

Nov 30, 2009:

Microsoft has recently come out with a Hot-Fix to Internet Explorer that changes the contents of the SPNEGO token in such a way that the JGSS runtime does not accept it. In particular, one will see the following in the logs:

[11/24/09 15:10:16:656 EST] 00000058 SystemOut O [JGSS_DBG_CTX] Received channel binding checksum
[11/24/09 15:10:16:656 EST] 00000058 SystemOut O [JGSS_DBG_MARSH] Encoded null channel binding
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R org.ietf.jgss.GSSException, major code: 1, minor code: 0
major string: Channel binding mismatch
minor string: ChannelBinding checksum failed verification
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R at com.ibm.security.jgss.i18n.I18NException.throwGSSException(I18NException.java:17)
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R at com.ibm.security.jgss.mech.krb5.p.a(p.java:703)
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R at com.ibm.security.jgss.mech.krb5.p.b(p.java:727)
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R at com.ibm.security.jgss.mech.krb5.p.acceptSecContext(p.java:162)
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R at com.ibm.security.jgss.mech.spnego.SPNEGOContext.processInitToken(Unknown Source)
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R at com.ibm.security.jgss.mech.spnego.SPNEGOContext.acceptSecContext(Unknown Source)
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R at com.ibm.security.jgss.GSSContextImpl.acceptSecContext(GSSContextImpl.java:214)
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R at com.ibm.security.jgss.GSSContextImpl.acceptSecContext(GSSContextImpl.java:269)
[11/24/09 15:10:16:656 EST] 00000058 SystemErr R at com.ibm.ws.security.spnego.Context.begin(Context.java:87)

WAS 5.1.1.4 through to WAS 7.0.0.7. instances that have implemented SPNEGO SSO with WAS, both the ISSW and the WebSphere based code, are effected by this.

To the end user, the impression is that they are no longer unable to login (yes, they can fall back to the Form Login, but most end users will not be aware of this back-door).

As of Nov 30, 2009, WAS development has not yet had a chance to create a fix.

 

 

Unable to resolve the Kerberos principal name

If unable to resolve the Kerberos principal name, as shown in the following trace example: 

[11/11/03 1:42:29:795 EST] 1d01b21e GetKrbToken   > Negotiation (GSS): Begin handshake
[11/11/03 1:42:29:795 EST] 1d01b21e Context       > GSS Context init, servername:HTTP@johnwang5.jwcmd.com
[11/11/03 1:42:29:866 EST] 1d01b21e TraceNLS      u No message text associated with key Error.getting.the.Token, .GSS.Exception:org.ietf.jgss.GSSException,.major.code:.13,.minor.code:.0
  major.string:.Invalid.credentials
  minor.string:.Cannot.get.credential.from.JAAS.Subject.for.principal:.HTTP/192.168.0.4@168.0.4 in bundle  com.ibm.ejs.resources.security
[11/11/03 1:42:29:866 EST] 1d01b21e GetKrbToken   E Error getting the Token, GSS Exception:org.ietf.jgss.GSSException,  major code: 13, minor code: 0
  major string: Invalid credentials
  minor string: Cannot get credential from JAAS Subject for principal: HTTP/192.168.0.4@168.0.4
[11/11/03 1:42:29:876 EST] 1d01b21e TraceNLS      u No message text associated with key SpnegoTAI.exits.due.to.an.exception.  in bundle com.ibm.ejs.resources.security
[11/11/03 1:42:29:876 EST] 1d01b21e SpnegoTAI     E SpnegoTAI exits due to an exception.

add the IP address of the server in its host file. You must also recycle the appserver to load the new host file.

 

WAS and the time on the Active Directory (AD) domain controller are not synchronized within 5 minutes

The trace.log file for this issue is similar to the following: 

[11/11/03 1:44:09:499 EST] 1d01b21e GetKrbToken   > Negotiation (GSS): Begin handshake
[11/11/03 1:44:09:499 EST] 1d01b21e Context       > GSS Context init, servername:HTTP@backendrc4.ibm.net
[11/11/03 1:44:09:499 EST] 1d01b21e Context       > GSS Context init, done.
[11/11/03 1:44:09:679 EST] 1d01b21e SpnegoTAI     > Server response token as follows...
0000:  6082014f 06062b06 01050502 a1820143     `?.O..+.....¡?.C
0010:  3082013f a0030a01 01a10b06 092a8648     0?.? ....¡...*?H
0020:  82f71201 0202a282 01290482 01256082     ?÷....¢?.).?.%`?
0030:  01210609 2a864886 f7120102 0203007e     .!..*?H?÷......~
0040:  82011030 82010ca0 03020105 a1030201     ?..0?.. ....¡...
0050:  1ea41118 0f323030 33313131 31303634     .¤...20031111064
0060:  3430395a a5050203 0a3548a6 03020125     409Z¥....5H¦...%
0070:  a90b1b09 4a57434d 442e434f 4daa2630     ©.....IBM.NETª&0
0080:  24a00302 0100a11d 301b1b04 48545450     $ ....¡.0...HTTP
0090:  1b136a6f 686e7761 6e67352e 6a77636d     ..backendrc4.ibm
00a0:  642e636f 6dab81ab 1b81a86f 72672e69     .net.«?«.?¨org.i
00b0:  6574662e 6a677373 2e475353 45786365     etf.jgss.GSSExce
00c0:  7074696f 6e2c206d 616a6f72 20636f64     ption, major cod
00d0:  653a2031 302c206d 696e6f72 20636f64     e: 10, minor cod
00e0:  653a2033 370a096d 616a6f72 20737472     e: 37..major str
00f0:  696e673a 20446566 65637469 76652074     ing: Defective t
0100:  6f6b656e 0a096d69 6e6f7220 73747269     oken..minor stri
0110:  6e673a20 436c6965 6e742074 696d6520     ng: Client time 
0120:  54756573 6461792c 204e6f76 656d6265     Tuesday, Novembe
0130:  72203131 2c203230 30332061 7420313a     r 11, 2003 at 1:
0140:  33353a30 3120414d 20746f6f 20736b65     35:01 AM too ske
0150:  776564                                  wed

You can fix this issue in one of two ways. The preferred method is to synchronize the WebSphere system time to within 5 minutes of the time of the AD server. A best practice is to use a time server to keep all of the systems synchronized. Alternatively, we can also add or adjust the clockskew parameter in the Kerberos configuration file. Note that the default is 300 seconds (5 minutes).

 

No factory is available to create name for mechanism 1.3.6.1.5.5.2

If the systemout.log file contains an exception error similar to the following: 

[4/8/05 22:51:24:542 EDT] 5003e481 SystemOut     O [JGSS_DBG_PROV] Provider IBMJGSSProvider version 1.01  does not support mech 1.3.6.1.5.5.2
[4/8/05 22:51:24:582 EDT] 5003e481 ServerCredent E com.ibm.issw.spnegoTAI.ServerCredential initialize() SPNEGO014:  Kerberos initialization Failure: org.ietf.jgss.GSSException, major code: 2, minor code: 0
  major string: Unsupported mechanism
  minor string: No factory available to create name for mechanism 1.3.6.1.5.5.2
  at com.ibm.security.jgss.i18n.I18NException.throwGSSException(I18NException.java:30)
  at com.ibm.security.jgss.GSSManagerImpl.a(GSSManagerImpl.java:36)
  at com.ibm.security.jgss.GSSCredentialImpl.add(GSSCredentialImpl.java:217)
  at com.ibm.security.jgss.GSSCredentialImpl.<init>(GSSCredentialImpl.java:264) 
.
.
make sure that the java.security file contains the IBMSPNEGO security provider and is defined correctly. It should contain a line similar to the following: 

security.provider.6=com.ibm.security.jgss.mech.spnego.IBMSPNEGO

 

A Kerberos error is received while decoding and verifying the SPNEGO token

We might receive the following exception error as the Java Generic Security Service (JGSS) library attempts to process the SPNEGO token: 

Error authenticating request. Reporting to client Major code = 11, Minor code = 31 org.ietf.jgss.GSSException, major code: 11, minor code: 31
  major string: General failure, unspecified at GSSAPI level
  minor string: Kerberos error while decoding and verifying token: com.ibm.security.krb5.internal.KrbException, status code: 31
  message: Integrity check on decrypted field failed

This error is caused when the ticket is encoded by using one key and then an attempt is made to decode the ticket by using another key. There are number of possible explanations for this:

If the problem is with the keytab file, then fix it. If the problem is with multiple SPN definitions, remove the extra or conflicting SPN, confirm that the SPN is no longer registered with AD, and then add the SPN again. Read about Create a Kerberos service principal and keytab file for more information. The Active Directory might need to be searched for other entries with SPNs defined that clash with the SPN using an LDAP browser. To confirm that the SPN is not registered, the following command: 

setspn –l userid
should return with: 

Cannot find account userid

If the userid and keytab are for DES-CBC-MD5, after you create the userid, change the password for the userid and then create the keytab file. If using Windows Server 2003 upgrade to the latest version of ktpass.

 

Single sign-on does not occur

When trace is turned on, the following error message might appear: 

Client sent back a non-SPNEGO authentication header, SpnegoTAI exits

A possible reason for this error is that the client is returning an NT LAN manager (NTLM) response to the authorize challenge, not an SPNEGO token. This can occur due to one or more of the following issues:

 

Unable to use sign-on (SSO) with RC4-HMAC encryption

When trace is turned on we might receive the following error message: 

com.ibm.security.krb5.internal.crypto.KrbCryptoException, status code: 0 message: Checksum error; received checksum does not match computed checksum

Some possible reasons for this error include the following

 

Credential delegation might not work due to an invalid option in the ticket request

When trace is turned on, if the following error message appears: 

com.ibm.security.krb5.KrbException, status code: 101 message: Invalid option in ticket request

the Kerberos configuration file is not properly configured. Ensure that neither renewable nor proxiable are set to true.

 

Problems when accessing a protected URL through the SPNEGO SSO

We might receive an error similar to the following when accessing a protected URL through the SPNEGO SSO: 

Bad Request

Your browser sent a request that this server could not understand. Size of request header field exceeds server limit.

 Authorization: Negotiate YII……

This message is generated by the Apache/IBM HTTP Server, and indicates that the authorization header that the browser has returned is too large. The long string that follows the word Negotiate is the SPNEGO token. This SPNEGO token is a wrapper of the Windows Kerberos token. Windows includes the PAC information of the user in the Kerberos token. The more security groups that the user belongs to, the more PAC information is inserted in the Kerberos token, and the larger SPNEGO becomes. IBM HTTP Server 2.0 (as well as Apache 2.0 and IBM HTTP Server 6.0) limit the size of any acceptable HTTP header to be 8K. In Windows domains with many groups, and with user membership in many groups, the size of the user’s SPNEGO token can exceed the 8K limit.

If possible, reduce the number of security groups that the user is a member of. IBM HTTP Server 2.0.47 cumulative fix PK01070 allows for HTTP header sizes up to and beyond the Microsoft limit of 12K.

After applying the fix specify the LimitRequestFieldSize parameter in the httpd.conf file to increase the size of allowable headers from the default of 8192.

 

Even with JGSS tracing disabled, some KRB_DBG_KDC messages appear in the SystemOut.log

While most of the JGSS tracing is controlled by the com.ibm.security.jgss.debug property, a small set of messages are controlled by the com.ibm.security.krb5.Krb5Debug property. The default value of the krb5 property is to emit some messages to SystemOut.log.

To remove all KRB_DBG_KDC messages from the SystemOut.log, set the JVM property to -Dcom.ibm.security.krb5.Krb5Debug=none.

 

ktpass is unable to find the userid

When using ktpass, we might receive an error message similar to the following: 

DsCrackNames returned 0x2 in the name entry for server3 Failed getting target domain for specified user.

In an Active Directory forest, the userid lookup used by the ktpass.exe does not have a default domain name to be used. This does not occur when the domain controller is not in a forest.

To fix this problem, instead of specifying option -mapUser userid, use -mapUser userid@domain instead. For example, specify –mapUser server3@WIBM.NET.

 

Credential delegation does not work for any userid

If in the trace.log, an error exception similar to the following appears: 

> com.ibm.issw.spnegoTAI.Context getDelegateCred() Entry d com.ibm.issw.spnegoTAI.Context getDelegateCred() unable to get Delegate Credential
< com.ibm.issw.spnegoTAI.Context getDelegateCred() Exit W com.ibm.issw.spnegoTAI.SpnegoHandler handleRequest() SPNEGO021: No delegated credentials were found for user: nauser@NA.IBM.NET

the domain account on which the SPN is attached does not have the “Account is trusted for Delegation” property defined.

To address this issue, verify the domain account does define the “Account is trusted for Delegation” property.

 

A user is challenged for credentials even though the browser is properly configured

A user might be challenged for credentials even though the browser is configured properly. The TAI might have obtained the user's credentials from the SPNEGO token, and the user might have failed to log in. In the trace.log an exception error similar to the following appears: 

< com.ibm.issw.spnegoTAI.SpnegoTAI getAuthenticatedUsername(): lansche Exit d com.ibm.issw.spnegoTAI.SpnegoTAI negotiateValidateandEstablishTrust(): Handshake finished, sending 200 :SC_OK
< com.ibm.issw.spnegoTAI.SpnegoTAI negotiateAndValidateEstablishedTrust Exit A SECJ0222E: An unexpected exception occurred when trying to create a LoginContext. The LoginModule alias is system.WEB_INBOUND  and the exception is...

The userid (which is lansche in the example above) does not exist in the registry in use by WebSphere. This problem can be caused when:

To fix this problem, verify the user that is being asserted to WAS by the TAI is the configured WebSphere registry.

 

A user using the Novell client cannot authenticate using SPNEGO

If a user using the Novell client cannot authenticate using SPNEGO they might receive a “An NTLM token is received.” message.

The user might have logged into the Novell Client but did not perform a Windows Kerberos login (this can be confirmed using the Kerbtray utility). If a user has logged onto the Windows domain and has a Kerberos ticket, the user cannot utilize SPNEGO authentication.

To fix this problem, remove the Novell client and use the default Windows domain login.

 

Accessing SPNEGO sites via some caching proxy servers can cause SPNEGO authentication issues

If we access SPNEGO sites via some caching proxy servers we might not be able to authenticate using SPNEGO. The message “SPNEGO authentication not supported on this client” might be displayed.

It is possible that the caching proxy is changing the hostname that returns on the HTTP 401 Authenticate Negotiate response.

If we have this issue, contact the proxy vendor for a possible solution.

 

Virtual Private Networks (VPN) software and firewalls might interfere with SPNEGO operations

We might experience problems with VPN software and firewalls that might interfere with SPNEGO operations.

To resolve these issues, contact the VPN and or firewall vendors for any configuration changes that might be necessary.

 

Possible browser issue when accessing a SPNEGO protected application

There might be a browser issue if we log onto a domain machine using one password (for example, passwordA) and then log onto a second domain machine by changing the original password (for example, we might change the password on the second domain machine to passwordB).

Once you return to the original domain machine, we might not be able to obtain either a SPNEGO/Kerberos or an NTLM response to the Negotiate challenge. After two attempts, the browser displays an HTTP 404 error message.

To resolve this issue, log off the original domain machine and log back on with the new password (passwordB).

 

Error pages defined for the NTLMTokenReceivedPage or the SpnegoNotSupportedPage properties do load from an http:// URL

The error pages defined for the NTLMTokenReceivedPage or the SpnegoNotSupportedPage properties do load from an http:// URL.

The following trace message might appear: 

Could not load the SPNEGO not supported content, going with the default content.  Exception received: java.net.ProtocolException: Server redirected too many  times (20)

This issue occurs when the loaded file performs an automatic redirect. It is not possible to both load the file from a Web Server and also use an automatic redirection

To resolve this issue, load the content from a file: /// URL, not an http:// URL.


 

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Troubleshooting security configurations