The ASP. NET Web API implements identity authentication with the authentication feature

1 usingSystem;2 usingSystem.Collections.Generic;3 usingSystem.Net.Http.Headers;4 usingSystem.Security.Principal;5 usingSystem.Text;6 usingSystem.Threading;7 usingSystem.Threading.Tasks;8 usingSystem.Web.Http.Filters;9 usingSystem.Web.Http.Results;Ten  One namespaceWebApi A { -[AttributeUsage (AttributeTargets.Class |AttributeTargets.Method)] -      Public classAuthenticateattribute:filterattribute, Iauthenticationfilter the     { -         Private Static ReadOnlydictionary<string,string>useraccounts; -  -         StaticAuthenticateattribute () +         { -UserAccounts =Newdictionary<string,string>(stringcomparer.ordinalignorecase) +             { A{"Foo","Password"}, at{"Bar","Password"}, -{"Baz","Password"} -             }; -         } -  -          PublicTask Authenticateasync (httpauthenticationcontext context, CancellationToken CancellationToken) in         { -IPrincipal user =NULL; to             varHeadervalue =context. Request.Headers.Authorization; +             if(NULL! = Headervalue && Headervalue.scheme = ="Basic") -             { the                 varCredential =Encoding.Default.GetString (convert.frombase64string (Headervalue.parameter)); *                 varSplit = credential. Split (':'); $                 if(split.) Length = =2)Panax Notoginseng                 { -                     varUserName = split[0]; the                     stringpassword; +                     if(Useraccounts.trygetvalue (UserName, outpassword)) A                     { the                         if(Password = = split[1]) +                         { -                             varIdentity =Newgenericidentity (userName); $user =NewGenericPrincipal (Identity,New string[0]); $                         } -                     } -                 } the             } -Context. Principal =user;Wuyi             returntask.fromresult<Object> (NULL); the         } -  Wu          PublicTask Challengeasync (httpauthenticationchallengecontext context, CancellationToken CancellationToken) -         { About             varuser =context. ActionContext.ControllerContext.RequestContext.Principal; $             if(NULL! = User && user. identity.isauthenticated)returntask.fromresult<Object> (NULL); -             varParameter = $"Realm={context. Request.RequestUri.DnsSafeHost}"; -             varChallenge =NewAuthenticationheadervalue ("Basic", parameter); -Context. Result =NewUnauthorizedresult (New[] {challenge}, context. Request); A             returntask.fromresult<Object> (NULL); +         } the     } -}

The ASP. NET Web API implements identity authentication with the authentication feature