WebApi 增加身份验证 （OAuth 2.0方式）

1，在Webapi项目下添加如下引用：

Microsoft.AspNet.WebApi.Owin

Owin

Microsoft.Owin.Host.SystemWeb

Microsoft.Owin.Security.OAuth

Microsoft.Owin.Security.Cookies

Microsoft.AspNet.Identity.Owin

Microsoft.Owin.Cors

2， 在项目下新建Startup类，这个类将作为owin的启动入口，添加下面的代码

3，修改 Startup类中方法

    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            // 有关如何配置应用程序的详细信息，请访问 http://go.microsoft.com/fwlink/?LinkID=316888
            ConfigAuth(app);

            HttpConfiguration config = new HttpConfiguration();
            WebApiConfig.Register(config);
            app.UseCors(CorsOptions.AllowAll);
            app.UseWebApi(config);
        }
        public void ConfigAuth(IAppBuilder app)
        {
            OAuthAuthorizationServerOptions option = new OAuthAuthorizationServerOptions()
            {
                AllowInsecureHttp = true,
                TokenEndpointPath = new PathString("/token"), //获取 access_token 授权服务请求地址
                AccessTokenExpireTimeSpan = TimeSpan.FromDays(1), //access_token 过期时间
                Provider = new SimpleAuthorizationServerProvider(), //access_token 相关授权服务
                RefreshTokenProvider = new SimpleRefreshTokenProvider() //refresh_token 授权服务
            };
            app.UseOAuthAuthorizationServer(option);
            app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());
        }
    }

4， OAuth身份认证，新建SimpleAuthorizationServerProvider类

    public class SimpleAuthorizationServerProvider : OAuthAuthorizationServerProvider
    {
        public override Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
        {
            context.Validated();
            return Task.FromResult<object>(null);
        }
        public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
        {
            context.OwinContext.Response.Headers.Add("Access-Control-Allow-Origin", new[] { "*" });
            AccountService accService = new AccountService();
            string md5Pwd = LogHelper.MD5CryptoPasswd(context.Password);
            IList<object[]> ul = accService.Login(context.UserName, md5Pwd);
            if (ul.Count() == 0)
            {
                context.SetError("invalid_grant", "The username or password is incorrect");
                return;
            }
            var identity = new ClaimsIdentity(context.Options.AuthenticationType);
            identity.AddClaim(new Claim("sub", context.UserName));
            identity.AddClaim(new Claim("role", "user"));
            context.Validated(identity);
        }
    }

5， 新建SimpleRefreshTokenProvider类

    public class SimpleRefreshTokenProvider : AuthenticationTokenProvider
    {
        private static ConcurrentDictionary<string, string> _refreshTokens = new ConcurrentDictionary<string, string>();

        /// <summary>
        /// 生成 refresh_token
        /// </summary>
        public override void Create(AuthenticationTokenCreateContext context)
        {
            context.Ticket.Properties.IssuedUtc = DateTime.UtcNow;
            context.Ticket.Properties.ExpiresUtc = DateTime.UtcNow.AddDays(60);

            context.SetToken(Guid.NewGuid().ToString("n"));
            _refreshTokens[context.Token] = context.SerializeTicket();
        }

        /// <summary>
        /// 由 refresh_token 解析成 access_token
        /// </summary>
        public override void Receive(AuthenticationTokenReceiveContext context)
        {
            string value;
            if (_refreshTokens.TryRemove(context.Token, out value))
            {
                context.DeserializeTicket(value);
            }
        }
    }

6， 在要加验证的接口上加上[Authorize]标记

    [Authorize]
    public class EmployeeController : ApiController
    {
        //查询所有员工
        [HttpGet]
        public IList<UC_Employee> GetAllEmps()
        {
　　　　　　    return new List<UC_Employee>();
        }
    }

7，调用api程序

8,传入参数，获取token

9，传入access_token