Added Web components for accessing the authenticated user

Author: jamesmcroft

src/MADE.Web/Identity/AuthenticatedUserAccessor.cs

@@ -0,0 +1,27 @@
+namespace MADE.Web.Identity
+{
+    using System.Security.Claims;
+    using Microsoft.AspNetCore.Http;
+
+    /// <summary>
+    /// Defines an accessor for retrieving the authenticated user from a <see cref="IHttpContextAccessor"/>.
+    /// </summary>
+    public class AuthenticatedUserAccessor : IAuthenticatedUserAccessor
+    {
+        private readonly IHttpContextAccessor httpContextAccessor;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AuthenticatedUserAccessor"/> class with an instance of the <see cref="IHttpContextAccessor"/>.
+        /// </summary>
+        /// <param name="httpContextAccessor">The <see cref="IHttpContextAccessor"/>.</param>
+        public AuthenticatedUserAccessor(IHttpContextAccessor httpContextAccessor)
+        {
+            this.httpContextAccessor = httpContextAccessor;
+        }
+
+        /// <summary>
+        /// Gets the authenticated user's claims principal.
+        /// </summary>
+        public ClaimsPrincipal ClaimsPrincipal => this.httpContextAccessor.HttpContext.User;
+    }
+}

src/MADE.Web/Identity/IAuthenticatedUserAccessor.cs

@@ -0,0 +1,15 @@
+namespace MADE.Web.Identity
+{
+    using System.Security.Claims;
+
+    /// <summary>
+    /// Defines an interface for accessing an authenticated user's claims principal.
+    /// </summary>
+    public interface IAuthenticatedUserAccessor
+    {
+        /// <summary>
+        /// Gets the authenticated user's claims principal.
+        /// </summary>
+        ClaimsPrincipal ClaimsPrincipal { get; }
+    }
+}