Fix (APAR):  PI56581

Status:  Fix

Release:  8.0.0.12,8.0.0.11,8.0.0.10,8.0.0.9

Operating System:  AIX,HP-UX,IBM i,Linux,Solaris,Windows,z/OS

Supersedes Fixes:  

CMVC Defect:  xxxxxx

Byte size of APAR:  285144

Date: 2016-08-09

Abstract:  signature in propagated saml token may not be valid due to added namespace declarations

Description/symptom of problem:  
PI56581 resolves the following problem:

ERROR DESCRIPTION:                                              
When a JAX-WS provider application receives a signed SAML       
token in an inbound SOAP request, then propagates the token to  
a downstream service, the token fails signature validation.     

LOCAL FIX:                                                      
N/A                                                             

PROBLEM SUMMARY

USERS AFFECTED:
 IBM WebSphere Application Server
administrators of WS-Security
enabled JAX-WS applications and SAML

PROBLEM DESCRIPTION:
SAML token may fail signature
validation after being propagated
by WS-Security

RECOMMENDATION:
 Install a fix pack that contains this
APAR.

After installing fix packs 7.0.0.39, 7.0.0.41, 8.0.0.11,
8.0.0.12, 8.5.5.7, 8.5.5.8 or 8.5.5.9, signed SAML tokens can
no longer be propagated on downstream JAX-WS or trust client
invocations.  If your scenario meets all of the following
conditions then you may experience this issue.
.
1. The SAML token is obtained from the Security header of a
JAX-WS web service request.
2. The WS-Security constraints for the service contains a
caller configuration for the SAML token.
3. The SAML token contains a signature.
4. The SAML token is not encrypted.
5. The SAML token to be sent is retrieved from the auth cache
or runAs subject.
6. The receiver of the token will validate the signature.
.
A SAML token may fail signature validation after being
propagated by WS-Security.  The XML in the token emitted will
differ from the one received on each element where a namespace
prefix is used.  The emitted XML will be logically the same as
the one received, but signature validation may fail.  For
example:
.
<saml2:Issuer>IS02</saml2:Issuer>
.
becomes
.
<saml2:Issuer
xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">IS02</saml2:
Issuer>
.
The following SAML token types are not affected:
* Unsigned SAML tokens
Although the XML is altered, since the token emitted is
logically the same as the one that was received, the token
will pass validation.
.
* Encrypted SAML tokens
Since the signature in an encrypted SAML token is included in
the encrypted token bytes, it cannot be modified.  After the
token is decrypted, the signature validation will pass.

PROBLEM CONCLUSION:                                             
To fix a memory leak, APAR PI32262 used an alternative cloning  
mechanism to clone a SAML token before it is put on the runAs   
subject.  This alternative cloning method produced an element   
that has XML that is logically the same, but the XML text is    
different.  The difference is that the namespace declaration    
is replicated on each element that uses a namespace prefix.     
In many cases that is ok, however, if the token was signed,     
the signature in the token will no longer be valid.             
                                                                
If the SAML token that has a signature is pulled from the       
runAs subject or auth cache and re-used in any way where the    
signature must be validated, the signature validation will      
fail.  For instance, it cannot be propagated on a downstream    
web services invocation or used in a trust client token         
exchange.                                                       
                                                                
A new cloning mechanism is added to ensure that all tokens are  
cloned in a way that their XML remains unchanged.  Previously,  
only for LTPA and SAML token token types were cloned before     
being added to the runAs subject. The implementation for this   
APAR will clone all token types before they are added to the    
runAs subject.                                                  
                                                                
The fix for this APAR is currently targeted for inclusion in    
fix packs 7.0.0.43, 8.0.0.13 and 8.5.5.10.  Please refer to     
the Recommended Updates page for delivery information:          
                                                                
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980   
                                                                
Keywords: IBMWL3WSS SAMLWSSEC                                   


Directions to apply fix:  Fix applies to Editions:
Release 8.0
_x_ Application Server (Express or BASE)
_x_ Network Deployment (ND)
__ Edge Components
__ Developer

Install Fix to all WebSphere installations unless special instructions are included below.

Special Instructions: None

NOTE:
The user must:
* Logged in with the same authority level when unpacking a fix, fix pack or refresh pack.
* Be at V1.4.3 or newer of the Installation Manager. Certain iFixes may require a newer version of the Installation Manager and the Installation Manager will inform you during the installation process if a newer version is required.

The IBM Knowledge Center can provide details, if needed, on the use of the Installation Manager to apply the iFixes.
http://publib.boulder.ibm.com/infocenter/install/v1r4/index.jsp.  Shutdown WebSphere Application Server before applying the iFixes.  Restart WebSphere Application Server after applying the iFixes.

Directions to remove fix:  

The IBM Knowledge Center can provide details, if needed, on the use of the Installation Manager to remove the iFixes.
http://publib.boulder.ibm.com/infocenter/install/v1r4/index.jsp.  Shutdown WebSphere Application Server before removing the iFixes.  Restart WebSphere Application Server after removing the iFixes.

Directions to re-apply fix:  
1) Shutdown WebSphere Application Server.

2) Follow the Fix instructions to apply the fix.

3) Restart WebSphere Application Server.



Additional Information: