Firebase 身份验证 asp.net 核心

Question

成功登录 Firebase 后，我们收到了一个 JWT 令牌。

为了向我的 asp.net 应用程序添加授权，我尝试将 JwtBearerAuthentication 添加到我的中间件。

我尝试了以下 JwtBearerOptions：

 var options = new JwtBearerOptions
        {
            Audience = "myApp",
            Authority = "https://securetoken.google.com"
        };

和

 var options = new JwtBearerOptions
        {
            Audience = "myApp",
            Authority = "https://securetoken.google.com/myApp"
        };

不幸的是，这不起作用。我的授权 URL 可能不正确。

有人知道哪个权威网址是正确的吗？

Answer 1

Firebase 在此处发布标准格式的 JWK：

https://www.googleapis.com/service_accounts/v1/jwk/securetoken@system.gserviceaccount.com

（尽管他们在文档中没有提及）

我在这里找到了这个信息：https://github.com/cfworker/cfworker/issues/89#issuecomment-748422827

Answer 2

JWT 验证需要手动：source

以下代码正在验证 FirebaseToken (JWT)：

    //Download certificates from google
    HttpClient client = new HttpClient();
    var jsonResult = client.GetStringAsync("https://www.googleapis.com/robot/v1/metadata/x509/securetoken@system.gserviceaccount.com").Result;

    //Convert JSON Result
    var x509Metadata = JObject.Parse(jsonResult)
                        .Children()
                        .Cast<JProperty>()
                        .Select(i => new x509Metadata(i.Path, i.Value.ToString()));

    //Extract IssuerSigningKeys
    var issuerSigningKeys = x509Metadata.Select(s => s.X509SecurityKey);

    //Setup JwtTokenHandler 
    var handler = new JwtSecurityTokenHandler();
    SecurityToken token;
    handler.ValidateToken(user.FirebaseToken, new TokenValidationParameters
    {
        IssuerSigningKeys = issuerSigningKeys,
        ValidAudience = "myApp",
        ValidIssuer = "https://securetoken.google.com/myApp",
        IssuerSigningKeyResolver = (arbitrarily, declaring, these, parameters) => issuerSigningKeys
    }, out token);

public class x509Metadata
{
    public string KID { get; set; }
    public string Certificate { get; set; }
    public X509SecurityKey X509SecurityKey { get; set; }

    public x509Metadata(string kid, string certificate)
    {
        KID = kid;
        Certificate = certificate;
        X509SecurityKey = BuildSecurityKey(Certificate);
    }

    private X509SecurityKey BuildSecurityKey(string certificate)
    {
        //Remove : -----BEGIN CERTIFICATE----- & -----END CERTIFICATE-----
        var lines = certificate.Split('\n');
        var selectedLines = lines.Skip(1).Take(lines.Length - 3);
        var key = string.Join(Environment.NewLine, selectedLines);

        return new X509SecurityKey(new X509Certificate2(Convert.FromBase64String(key)));
    }
}