remapping NameID in service provider to Alias attribute from office365 identity provider - wso2

Question

I am setting up wso2 between office365 and a help desk app that uses SAML 2 for auth. the app expect username in NameID.wso2is identity providers sends guid-like id in the NameID field instead of the alias field which i need in my app.
I already did all the steps from this doc https://github.com/wso2-extensions/identity-outbound-auth-office365/blob/v1.0.4/docs/config.md in addition to defining an Alias claim and then in service provider added a custom mapping for NameID to alias nad specified subject uri to NameID claim
<saml2:Subject>
<saml2:NameID Format="urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified">0cccccc-444444-45553-1111-92387492387#23423423-sdfs-3333-5555-222222222</saml2:NameID>
<saml2:AttributeStatement>
<saml2:Attribute Name="Alias"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:basic"
>
<saml2:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="xs:string"
>j.smith</saml2:AttributeValue>
</saml2:Attribute>
<saml2:Attribute Name="DisplayName"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:basic"
>
<saml2:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="xs:string"
>John Smith</saml2:AttributeValue>
</saml2:Attribute>
<saml2:Attribute Name="Id"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:basic"
>
<saml2:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="xs:string"
>0cccccc-444444-45553-1111-92387492387#23423423-sdfs-3333-5555-222222222</saml2:AttributeValue>
</saml2:Attribute>
<saml2:Attribute Name="#odata.context"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:basic"
>
<saml2:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="xs:string"
>https://outlook.office365.com/api/v2.0/$metadata#Me</saml2:AttributeValue>
</saml2:Attribute>
<saml2:Attribute Name="EmailAddress"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:basic"
>
<saml2:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="xs:string"
>a#b.com</saml2:AttributeValue>
</saml2:Attribute>
</saml2:AttributeStatement>
</saml2:Assertion>
I need NameID to be NameID to be j.smith from alias attribute
j.smith

Answer 1

Just select the required claim for the Subject Claim URI in the service provider claim configurations. Subject Claim URI defines the authenticated user identifier which will return with the authentication response to the service provider. This will be returned as the NameID in the SAML response.
You can refer this document for more info on service provider claim configuration.