[Feature Request] Support additional properties for POP token generation

[johnthcall]

MSAL client type

Confidential

Problem statement

Currently POP token generation supports the requests Method, Host, and Path to be part of the signed body. Packages like Microsoft.IdentityModel.Protocols.SignedHttpRequest have dictionaries like AdditionalPayloadClaims for additional aspects of the request.

Proposed solution

Add property AdditonalPayloadClaims to PoPAuthenticationConfiguration and leverage it in PopAuthenticationOperation.CreateBody.

Alternatives

No response

[bgavrilMS]

For confidential client scenarios, we are looking at moving to mTLS POP.