### Is your feature request related to a problem? Please describe... I am trying to connect to a SAML IDP which expects a http://www.w3.org/2007/05/xmldsig-more#sha256-rsa-MGF1 Signature as described in rfc6931 [RSASSA-PSS without Parameters](https://www.rfc-editor.org/rfc/rfc6931.html#section-2.3.10). Unfortunately, I am a bit stuck on how to implement it. ### Describe teh solution you'd like... I would like to have a new option to use http://www.w3.org/2007/05/xmldsig-more#sha256-rsa-MGF1 signatures. ### Describe the alternatives you've considered... I tried to use https://github.com/digitalbazaar/forge to calculate the signature, but did not have any success.