aspnetcore/src/Microsoft.AspNetCore.Authentication/AuthenticationServiceCollectionExtensions.cs

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using Microsoft.AspNet.Authentication;

namespace Microsoft.Extensions.DependencyInjection
{
    /// <summary>
    /// Extension methods for setting up authentication services in an <see cref="IServiceCollection" />.
    /// </summary>
    public static class AuthenticationServiceCollectionExtensions
    {
        /// <summary>
        /// Adds authentication services to the specified <see cref="IServiceCollection" />. 
        /// </summary>
        /// <param name="services">The <see cref="IServiceCollection" /> to add services to.</param>
        /// <returns>A reference to this instance after the operation has completed.</returns>
        public static IServiceCollection AddAuthentication(this IServiceCollection services)
        {
            if (services == null)
            {
                throw new ArgumentNullException(nameof(services));
            }

            services.AddWebEncoders();
            services.AddDataProtection();
            return services;
        }

        /// <summary>
        /// Adds authentication services to the specified <see cref="IServiceCollection" />. 
        /// </summary>
        /// <param name="services">The <see cref="IServiceCollection" /> to add services to.</param>
        /// <param name="configureOptions">An action delegate to configure the provided <see cref="SharedAuthenticationOptions"/>.</param>
        /// <returns>A reference to this instance after the operation has completed.</returns>
        public static IServiceCollection AddAuthentication(this IServiceCollection services, Action<SharedAuthenticationOptions> configureOptions)
        {
            if (services == null)
            {
                throw new ArgumentNullException(nameof(services));
            }

            if (configureOptions == null)
            {
                throw new ArgumentNullException(nameof(configureOptions));
            }

            services.Configure(configureOptions);
            return services.AddAuthentication();
        }
    }
}