Add in the Microsoft.IdentityModel.Tokens.Jwt library

[mafurman]

The library should meet the following requirements:

• Remove automatic short-to-long claim type mapping that occurs when tokens are created.
• Prepare a framework for future work that will involve asynchronous token validation and creation.
• Improve the speed of JWT token validation and creation.
• Simplify the way in which JWT tokens are stored and dealt with.
• Provide a single extensibility model using delegates. Previous models provided two models: virtual methods and delegates.

[brentschmaltz]

library was added

[EatonZ]

Is it safe to assume that JsonWebTokenHandler is basically the new version of JwtSecurityTokenHandler? I've been using JwtSecurityTokenHandler and I saw the latest version added JsonWebTokenHandler. Is there a reason to use one over the other? Looking over it, it seems the basic difference is encryption support, but I just want some additional clarification here on why this new handler was added.

[EatonZ]

Hi @mafurman @brentschmaltz, any insight into the above?

[brentschmaltz]

@EatonZ JwtSecurityTokenHandler was modeled after the existing System.IdentityModel.SecurityTokenHandler. There were some compromises that we had to make, such as using System.Security.ClaimsIdentity as the type to build the JWS or JWE when using SecurityTokenDescriptor. ValidateToken had an out parameter of type SecurityToken, which doesn't for async.
A ClaimsPrincipal was returned, sometimes using claim type mapping to build the claims.
This model new model, is much lighter weight and works with native Json.Net objects.
We plan on layering on top, so that you can get back to the existing types, but we will allow users to control what is returned using injection and delegates.

We saw performance improvements of up to 100% in some scenarios.