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>();
    }
}