基于asp.net MVC 的服务器和客户端的交互(二)之获取Oauth 2.0认证权限

基本Web API的ASP.NET的Oauth2认证

• 增加Token额外字段
• 增加Scope授权字段
• 持久化Token
• 设计Token的时间间隔
• 刷新Token后失效老的Token
• 自定义验证【重启IIS池Token失效,验证权限】

Oauth2 认证的流程

客户端发送口令（grant_type,client_id,client_secret）到服务端请求，认证返回access token ,然后客户端跟据获得的access token，根据Access Token获得权限去访问Web API.

配置与准备：此处我们使用 oauth2服务端实现，需要引入Authorize（授权服务器依赖）和resourceserver（资源服务器依赖）。

加了Authorize 标志之后，进行 API请求测试，如果不通过oauth2认证机制就会出现，请求被拒绝

开始时，当程序开始时，客户端访问API，设计进入安全认证状态

1   public void Configuration(IAppBuilder app)
2         {
3
4             app.UseCors(CorsOptions.AllowAll);
5             ConfigureAuth(app);
6         }

 1  app.UseOAuthBearerTokens(new OAuthAuthorizationServerOptions
 2             {
 3                 TokenEndpointPath = new PathString("/token"),
 4                 Provider = new ApplicationOAuthProvider(),
 5                 //RefreshTokenProvider = new ApplicationRefreshTokenProvider(),
 6                 AccessTokenExpireTimeSpan = TimeSpan.FromHours(2),
 7                 AuthenticationMode = AuthenticationMode.Active,
 8                 //HTTPS is allowed only AllowInsecureHttp = false
 9                 AllowInsecureHttp = true
10                 //ApplicationCanDisplayErrors = false
11             });

第一步：根据密码口令获得Access Token(当密码和账号正确时)

        /// <summary>
        /// 验证客户[client_id与client_secret验证]
        /// </summary>
        /// <param name="context"></param>
        /// <returns></returns>
        public override Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
        {
            //http://localhost:48339/token
            //grant_type=client_credentials&client_id=irving&client_secret=123456
            string client_id;
            string client_secret;
            context.TryGetFormCredentials(out client_id, out client_secret);
            if (client_id == "abc" && client_secret == "123456")
            {
                context.Validated(client_id);
            }
            else
            {
                //context.Response.StatusCode = Convert.ToInt32(HttpStatusCode.OK);
                context.SetError("invalid_client", "client is not valid");
            }
            return base.ValidateClientAuthentication(context);
        }

 /// <summary>
        /// 客户端授权[生成access token]
        /// </summary>
        /// <param name="context"></param>
        /// <returns></returns>
        public override Task GrantClientCredentials(OAuthGrantClientCredentialsContext context)
        {
            /*
                 var client = _oauthClientService.GetClient(context.ClientId);
                 oAuthIdentity.AddClaim(new Claim(ClaimTypes.Name, client.ClientName));
             */

            //var oAuthIdentity = new ClaimsIdentity(context.Options.AuthenticationType);
            //oAuthIdentity.AddClaim(new Claim(ClaimTypes.Name, "iphone"));
            //var ticket = new AuthenticationTicket(oAuthIdentity, new AuthenticationProperties() { AllowRefresh = true });
            //context.Validated(ticket);
            //return base.GrantClientCredentials(context);
            var oAuthIdentity = new ClaimsIdentity(context.Options.AuthenticationType);
            oAuthIdentity.AddClaim(new Claim(ClaimTypes.Name, "iphone"));
            //可以加入用户信息及其他必要信息到Token中，以便在api服务中使用(使用中HttpContext.Current.User.Identity即为oAuthIdentity对象，WebApi的Controller中可直接使用User.Identity)。
            oAuthIdentity.AddClaim(new Claim("UserID", "irving"));
            var ticket = new AuthenticationTicket(oAuthIdentity, new AuthenticationProperties());
            context.Validated(ticket);//认证通过
            return base.GrantClientCredentials(context);
        }

　第二步：刷新Token

 /// <summary>
        /// 刷新Token[刷新refresh_token]
        /// </summary>
        /// <param name="context"></param>
        /// <returns></returns>
        public override Task GrantRefreshToken(OAuthGrantRefreshTokenContext context)
        {
            //enforce client binding of refresh token
            if (context.Ticket == null || context.Ticket.Identity == null || !context.Ticket.Identity.IsAuthenticated)
            {
                context.SetError("invalid_grant", "Refresh token is not valid");
            }
            else
            {
                //Additional claim is needed to separate access token updating from authentication
                //requests in RefreshTokenProvider.CreateAsync() method
            }
            return base.GrantRefreshToken(context);
        }

　　接下来就是可以使用客户端通过账号密码对客户端进行调用，在一随笔中详细介绍。