Invalid AuthnRequest because of &

[lucasmenezesaurea]

In assertionConsumerServiceUrl if URL contains & it is decoded to & . Consequently, AuthnRequest XML is invalid because contains & without encoding.
Some IdP can't parse the XML because it is invalid. This does not happens for OneLogin IdP.

[mauromol]

I think this is due to #309.

[mauromol]

@lucasmenezesaurea I provided a PR that I hope @pitbulk will evaluate. Re-reading again your report, though, I'm not sure I understood it right.
You say that if your ACS URL contains &amp it gets decoded to &... but when? Perhaps after signing?

Before my PR, the com.onelogin.saml2.authn.AuthnRequest.getAuthnRequestXml() method returned an XML message containing all text strings specified in settings literally, so if your URL contained &, the unsigned XML was generated containing &, with no change. I guess that, if you sign that XML file, the signature process, which parses back the XML and then produces a signed version of the same XML file, may indeed parse & as & and hence produce the wrong result.

With my PR, any text (URLs, organization names, other string configuration parameters) are properly escaped when generating the unsigned XML messages, so a URL which should contain & will be escaped as & and hence the signing process should correctly parse it back as & to produce its own output.

Perhaps you may try to build from my branch (https://github.com/mauromol/java-saml/tree/escape-strings-in-xml) and see?

[lucasmenezesaurea]

This is the SP metadata:

<?xml version="1.0"?>

<md:EntityDescriptor xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata" entityID="https://mygnx-qualif/ace202-webgce">

                <md:SPSSODescriptor AuthnRequestsSigned="false" WantAssertionsSigned="false" protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol">

                               <md:SingleLogoutService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect" Location="https://mygnx-qualif/java-saml-tookit-jspsample/sls.jsp"/>

                               <md:NameIDFormat>urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified</md:NameIDFormat>

                               <md:AssertionConsumerService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="https://mygnx-qualif/ace202-webgce/GCE/ServletControl?cinematic=login%28Login%29&amp;chp%3AENTITY=1&amp;sourceview=LOGIN" index="1"/>

                </md:SPSSODescriptor>

                <md:Organization>

                               <md:OrganizationName xml:lang="en">Aurea</md:OrganizationName>

                               <md:OrganizationDisplayName xml:lang="en">Aurea Collaborative Enterprise</md:OrganizationDisplayName>

                               <md:OrganizationURL xml:lang="en">https://www.aurea.com/library/collaborative-enterprise/</md:OrganizationURL>

                </md:Organization>

</md:EntityDescriptor>

This is AuthnRequest:

<samlp:AuthnRequest xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" ID="ONELOGIN_11baec22-8fe2-49cc-8cf4-6e60977f6a60" Version="2.0" IssueInstant="2021-03-29T08:11:11Z" ProviderName="Aurea Collaborative Enterprise" Destination="https://ssopp.ramsaygds.fr/samlv2/AccueilAuth/IdPAccess/Generix_Qualif" ProtocolBinding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" AssertionConsumerServiceURL="https://mygnx-qualif/ace202-webgce/GCE/ServletControl?cinematic=login%28Login%29&chp%3AENTITY=1&sourceview=LOGIN"><saml:Issuer>https://mygnx-qualif/ace202-webgce</saml:Issuer><samlp:NameIDPolicy Format="urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified" AllowCreate="true" /><samlp:RequestedAuthnContext Comparison="exact"><saml:AuthnContextClassRef>urn:oasis:names:tc:SAML:2.0:ac:classes:Password</saml:AuthnContextClassRef></samlp:RequestedAuthnContext></samlp:AuthnRequest>

The error happens when IdP tries to proccess this AuthnRequest.
See &chp is not scaped into &chp . If you try to format this XML (e.g. https://www.freeformatter.com/xml-formatter.html) you will se the AuthnRequest is invalid.

[mauromol]

The error is clear, what I still don't fully understand, since your AuthRequest seems not to be signed, is how you generate the AuthRequest. In particular, do you specify the ACS URL in the settings file (or in a dynamic settings map)?

[lucasmenezesaurea]

Hello @mauromol
replace all & by %26 after authnRequest.getEncodedAuthnRequest();
IdP will accept the request

workaround is to avoid & in your md:AssertionConsumerService , by replacing all & to %26

[mauromol]

I believe this is closed by #315.