WSO2 Identity Server OAuth2 Bearer SAML Assertion - oauth-2.0

Question

I encountered a problem in using WSO2 Identity Server.
I have a web server using SAML2 in Identity Server for SSO.
After login, Identity Server return the saml response message:
<?xml version="1.0" encoding="UTF-8"?>
<saml2p:Response Destination="http://localhost:8080/travelocity.com/home.jsp" ID="lfkelagpefmnohdlcalkpoeobnahpjapkfljnoah" InResponseTo="mieoddeiiebbaphejlfdgaiojbnogmpnnhijaema" IssueInstant="2016-01-02T17:31:47.863Z" Version="2.0" xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol"><saml2:Issuer Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity" xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">localhost</saml2:Issuer><ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:SignedInfo><ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/><ds:Reference URI="#lfkelagpefmnohdlcalkpoeobnahpjapkfljnoah"><ds:Transforms><ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/><ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/></ds:Transforms><ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><ds:DigestValue>HCnAalpftzdBW6dZbB+0nJf2A7c=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>QKXtIMRFkw/eqAX1b30PGbCHqPTYrlOEGl0UobvK/hqaYz+2wuoJfMz9t0BS5CFYUT/OqAsv9eR2IVTDUq+Wp17xOu48yAPI9gl9L1gH9YZ4+k12y19C3WbAgTwaZ+IOqa9a01N5nWAKa3G38rhX58KAX31FgILvFT6aegQYXMU=</ds:SignatureValue><ds:KeyInfo><ds:X509Data><ds:X509Certificate>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</ds:X509Certificate></ds:X509Data></ds:KeyInfo></ds:Signature><saml2p:Status><saml2p:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/></saml2p:Status><saml2:Assertion ID="jajekgbkamaadloajjnhckhdofjdiicgkcfbjbmd" IssueInstant="2016-01-02T17:31:47.863Z" Version="2.0" xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion"><saml2:Issuer Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">localhost</saml2:Issuer><ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:SignedInfo><ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/><ds:Reference URI="#jajekgbkamaadloajjnhckhdofjdiicgkcfbjbmd"><ds:Transforms><ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/><ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/></ds:Transforms><ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><ds:DigestValue>pDzChf9Ote3Ljws9ErogUQxfN0I=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>ZFw9zwyuB2xJuChBdkQArV+yb2NW0LcTkoZK+GuhTRqoD/Ndk880U18cRT4am/Ut1qxIR90ec9pqosCd9ax/UZzu/ZZ69mNfn0xB6Uni/1MQ9G+FijjmuTHPWK2jyO1PrkbK7OUNTD1UgQxQGaMufbuWR2BsNFWnRbLBB5PG8e0=</ds:SignatureValue><ds:KeyInfo><ds:X509Data><ds:X509Certificate>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</ds:X509Certificate></ds:X509Data></ds:KeyInfo></ds:Signature><saml2:Subject><saml2:NameID Format="urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress">admin#carbon.super</saml2:NameID><saml2:SubjectConfirmation Method="urn:oasis:names:tc:SAML:2.0:cm:bearer"><saml2:SubjectConfirmationData InResponseTo="mieoddeiiebbaphejlfdgaiojbnogmpnnhijaema" NotOnOrAfter="2016-01-02T17:36:47.863Z" Recipient="http://localhost:8080/travelocity.com/home.jsp"/></saml2:SubjectConfirmation><saml2:SubjectConfirmation Method="urn:oasis:names:tc:SAML:2.0:cm:bearer"><saml2:SubjectConfirmationData InResponseTo="mieoddeiiebbaphejlfdgaiojbnogmpnnhijaema" NotOnOrAfter="2016-01-02T17:36:47.863Z" Recipient="https://localhost:9443/oauth2/token"/></saml2:SubjectConfirmation></saml2:Subject><saml2:Conditions NotBefore="2016-01-02T17:31:47.863Z" NotOnOrAfter="2016-01-02T17:36:47.863Z"><saml2:AudienceRestriction><saml2:Audience>travelocity.com</saml2:Audience><saml2:Audience>https://localhost:9443/oauth2/token</saml2:Audience></saml2:AudienceRestriction></saml2:Conditions><saml2:AuthnStatement AuthnInstant="2016-01-02T17:31:47.864Z" SessionIndex="fed8981e-65b5-4a07-b7b0-b5b2dfcd1c35"><saml2:AuthnContext><saml2:AuthnContextClassRef>urn:oasis:names:tc:SAML:2.0:ac:classes:Password</saml2:AuthnContextClassRef></saml2:AuthnContext></saml2:AuthnStatement></saml2:Assertion></saml2p:Response>
I extract the Assertion tag from the SAML2 response and encode it using base64 and send the request to the identity server for requesting the OAuth2 Bearer token using OAuth2 SAML Aseertion.
However I got the following exception message in the server:
[2016-01-02 12:33:34,938] ERROR {org.wso2.carbon.identity.oauth2.token.handlers.grant.saml.SAML2BearerGrantHandler} - Error while validating the signature.
org.opensaml.xml.validation.ValidationException: Signature did not validate against the credential's key
at org.opensaml.xml.signature.SignatureValidator.validate(SignatureValidator.java:78)
at org.wso2.carbon.identity.oauth2.token.handlers.grant.saml.SAML2BearerGrantHandler.validateGrant(SAML2BearerGrantHandler.java:451)
at org.wso2.carbon.identity.oauth2.token.AccessTokenIssuer.issue(AccessTokenIssuer.java:154)
at org.wso2.carbon.identity.oauth2.OAuth2Service.issueAccessToken(OAuth2Service.java:196)
at org.wso2.carbon.identity.oauth.endpoint.token.OAuth2TokenEndpoint.getAccessToken(OAuth2TokenEndpoint.java:245)
at org.wso2.carbon.identity.oauth.endpoint.token.OAuth2TokenEndpoint.issueAccessToken(OAuth2TokenEndpoint.java:111)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:188)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:104)
at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:204)
at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:101)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:58)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:94)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:272)
at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:249)
at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:248)
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:222)
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:153)
at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:171)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:289)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doPost(AbstractHTTPServlet.java:209)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:265)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.wso2.carbon.ui.filters.CSRFPreventionFilter.doFilter(CSRFPreventionFilter.java:88)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.wso2.carbon.ui.filters.CRLFPreventionFilter.doFilter(CRLFPreventionFilter.java:59)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.wso2.carbon.tomcat.ext.valves.CompositeValve.continueInvocation(CompositeValve.java:99)
at org.wso2.carbon.tomcat.ext.valves.CarbonTomcatValve$1.invoke(CarbonTomcatValve.java:47)
at org.wso2.carbon.webapp.mgt.TenantLazyLoaderValve.invoke(TenantLazyLoaderValve.java:57)
at org.wso2.carbon.tomcat.ext.valves.TomcatValveContainer.invokeValves(TomcatValveContainer.java:47)
at org.wso2.carbon.tomcat.ext.valves.CompositeValve.invoke(CompositeValve.java:62)
at org.wso2.carbon.tomcat.ext.valves.CarbonStuckThreadDetectionValve.invoke(CarbonStuckThreadDetectionValve.java:159)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.wso2.carbon.tomcat.ext.valves.CarbonContextCreatorValve.invoke(CarbonContextCreatorValve.java:57)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1074)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1739)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1698)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
I only set the SAML2 service provider in the Identity Server and use the default Resident Identity Provider as the identity provider in Identity Server.
Am i doing something wrong in the OAuth2 SAML Assertion flow or Am I missing some configuration in the server?
Thank you very much.

Answer 1

You need to extract the Assertion tag from the SAML2 response and convert it to base64 URL encode. please follow the steps below.
you need to remove the line breaks.
URL encode
encode base 64 the client ID and client secret
(note : you can directly convert it to base64 URL encode, no need to do this using two steps)
then use below curl command
curl -k -d "grant_type=urn:ietf:params:oauth:grant-type:saml2-bearer&assertion=<Assertion_provided_by_client>&scope=PRODUCTION" -H "Authorization: Basic <Base64 encoded consumer key:consumer secret>, Content-Type: application/x-www-form-urlencoded" https://<IP of the APIM server>:9443/oauth2/token
This error occurs when the assertion signed private key's public key and the verification public key does not match. So in this case the public key used at API Manger side to validate the send in SAML assertion has not matched with the private key used at Identity Server to sign the SAML assertion.
The other option is to add the certificate they provide you to the wso2carbon.jks (and remember the alias).
please refer below references for more info.
[1] https://docs.wso2.com/display/AM190/Exchanging+SAML2+Bearer+Tokens+with+OAuth2+-+SAML+Extension+Grant+Type
[2]https://docs.wso2.com/display/IS510/SAML2+Bearer+Assertion+Profile+for+OAuth+2.0+with+WSO2+Travelocity
[3] http://xacmlinfo.org/2014/10/31/saml2-bearer-assertion-profile-for-oauth-2-0/