Asp.net Database Authentication for Firebase

Question

After successfully logging into Firebase, we got a JWT token.

To add authorization to my asp.net application, I tried to add JwtBearerAuthentication to my middleware.

I tried the following JwtBearerOptions:

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

and

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

Unfortunately this does not work. My Auhtority URL is probably invalid.

Does anyone know if Auhtority URL is correct?

Answer 1

JWT verification must be manual: source

The following code checks the FirebaseToken (JWT):

  //Download certificates from google HttpClient client = new HttpClient(); var jsonResult = client.GetStringAsync("https://www.googleapis.com/robot/v1/metadata/x509/ [e-mail] ").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))); } }