public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            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());
        }
    }

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[] { "*" });
        //验证用户名密码
        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);
    }
}

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);
        }
    }
}

 [Authorize]
    public class DefaultController : ApiController
    {
        [HttpPost]
        public string getPost()
        {
            return JsonConvert.SerializeObject(new { state = 1, msg = "ok" });
        }

        [HttpGet]
        [AllowAnonymous]
        public string validatePass(string name)
        {
            return JsonConvert.SerializeObject(new { state = 2, msg = "validatePass_ok" });
        }
    }