Can I redirect users to login pages in different languages?

[Peter Schober]

* Mert metin <mertmetin at outlook.com> [2015-03-12 19:48]:
> My application uses Shibboleth. Shibboleth.sso/Login page redirects me to my customer's iDP server which is fine. This login page is English. There is also French version. What I want to do is to send users login pages according to their default language in my application.  I use below link for login process.
> https://myapp.com/Shibboleth.sso/Login?entityID=https://dev.mycustomersidpserver.ca/idp/
> 
> So Can I tell my service provider to send to related login page?

I wouldn't know how, other than putting an extension into the SAML2
authentication request (that's the thing the SP sends to the IDP) and
agreeing with the IDP on the expected behaviour, i.e., the IDP must be
willing to implement this.
(The extension could contain a SAML attribute element with
preferredLanguage/urn:oid:2.16.840.1.113730.3.1.39 and the ISO639
code as value.)

/But/ it would be much easier for the IDP to just parse the HTTP User
Agent's Accept-Language HTTP request header and select the language
based on that, plus probably allowing the subject to change the
language herself while at the login page.

Either way, without the IDP's cooperation there's nothing you can do.
-peter