Top 20 NuGet oauth2 Packages

OpenID Connect & OAuth 2.0 client library
Chilkat .NET Class Library (64-bit) for SSH/SFTP, FTP, POP3, SMTP, IMAP, SSL/TLS, Zip, REST, OAuth2, HTTP, RSA, XML DSig, Encryption, Compression, XML, Socket, XMP, HTML to XML, JSON, JWT, OAuth1, conversion, PKCS12/PFX, Java Keystore, ASN.1, PEM, ECC, Async, ...
OpenID Connect and OAuth 2.0 Framework for ASP.NET Core
ASP.NET Core 2.0 Middleware for validating tokens using OAuth 2.0 introspection
ASP.NET Core authentication handler to validate JWT and reference tokens from IdentityServer4
Package Description
Access token validation middleware for JWT and reference tokens issued by IdentityServer3.
Provides various authenticators for user authentication in Crosslight apps, including HttpBasic, NTLM, OAuth, OAuth2, and WebAPI authenticator.
EntityFramework persistence layer for IdentityServer4
ASP.NET Core Identity Integration for IdentityServer4
Package Description
ASP.NET Identity support for IdentityServer3 repackaged as a dll client library, preventing the addition of volatile source code to the destination project
Chilkat .NET Core Class Library
A Rest-only client for DSharpPlus.
Helper library for claims based identity & access control in ASP.NET Web API v2.
Helper library for claims based identity & access control in OWIN/Katana based applications.
ASP.NET Core Middleware for validating scope claims
Chilkat .NET Class Library (32-bit) for SSH/SFTP, FTP, POP3, SMTP, IMAP, SSL/TLS, Zip, REST, OAuth2, HTTP, RSA, XML DSig, Encryption, Compression, XML, Socket, XMP, HTML to XML, JSON, JWT, OAuth1, conversion, PKCS12/PFX, Java Keystore, ASN.1, PEM, ECC, Async, ...
IdentityServer is a framework and a hostable component that allows implementing single sign-on and access control for modern web applications and APIs using protocols like OpenID Connect and OAuth2. It supports a wide range of clients like mobile, web, SPAs and desktop applications and is extensible...
Adds OAuth2 Providers for use in ServiceStack Web and REST Services. Includes built-in support for Google and LinkedIn OAuth2 providers. More Info on Auth Providers: http://docs.servicestack.net/authentication-and-authorization