Have a look at Authen::NZRealMe and its sub modules

Authen::NZRealMe	Integrate with RealMe login and identity services (formerly "igovt logon")
Authen::NZRealMe::AuthenRequest	Generate a SAML2 AuthenRequest message
Authen::NZRealMe::ICMSResolutionRequest	Generate a WS-Trust request for resolving an opaque token to a RealMe FLT.
Authen::NZRealMe::IdentityProvider	Class representing the NZ RealMe Login SAML IdP
Authen::NZRealMe::LogonStrength	Manipulate NZ RealMe Login service AuthnContextClassRef values
Authen::NZRealMe::ResolutionRequest	Generate a SOAP request for resolving an artifact to an FLT
Authen::NZRealMe::ResolutionResponse	Encapsulates the response from the IdP to the artifact resolution request
Authen::NZRealMe::ServiceProvider	Class representing the local SAML2 Service Provider
Authen::NZRealMe::ServiceProvider::Builder	interactively create/edit Service Provider metadata
Authen::NZRealMe::ServiceProvider::CertFactory	generate certificates or CSRs
Authen::NZRealMe::TokenGenerator	generate SAML ID strings
Authen::NZRealMe::XMLSig	XML digital signature generation/verification