Firebase 3：使用 .net 和 C# 创建自定义身份验证令牌

Question

我正在尝试使用自定义令牌实施 Firebase 3 身份验证机制（如 https:// firebase.google.com/docs/auth/server/create-custom-tokens 所述）。

我的服务器是 ASP.NET MVC 应用程序。

因此，根据说明 (https://firebase.google.com/docs/server/setup)，我为我的 Firebase 应用程序创建了一个服务帐户，并生成了一个“.p12”格式的密钥。

之后，根据此处的说明 (https://firebase.google.com/docs/auth/server/create-custom-tokens#create_custom_tokens_using_a_third-party_jwt_library)，我尝试生成自定义令牌并使用上一步收到的密钥对其进行签名。对于令牌生成，我使用了 Microsoft 的 SystemIdentityModel.Tokens.Jwt 库，因此代码如下所示：

var now = DateTime.UtcNow;
var tokenHandler = new JwtSecurityTokenHandler();
var key = new X509AsymmetricSecurityKey(new X509Certificate2(p12path, p12pwd));
var signinCredentials = new SigningCredentials(key, "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256", "http://www.w3.org/2001/04/xmlenc#rsa-sha256");
Int32 nowInUnixTimestamp = (Int32)(now.Subtract(new DateTime(1970, 1, 1))).TotalSeconds;

var token = tokenHandler.CreateToken(
            issuer: serviceAccountEmail,
            audience: "https://identitytoolkit.googleapis.com/google.identity.identitytoolkit.v1.IdentityToolkit",                
            signingCredentials: signinCredentials,
            subject: new ClaimsIdentity(new Claim[]
                    {
                    new Claim("sub", serviceAccountEmail),
                    new Claim("iat", nowInUnixTimestamp.ToString()),
                    new Claim("exp", (nowInUnixTimestamp + (60*60)).ToString()),
                    new Claim("uid", uid)
                    })
            );

var tokenString = tokenHandler.WriteToken(token);

然后尝试使用 Firebase Javascript SDK 在 React Native 应用程序中登录用户，代码如下：

//omitting initialization code
firebase.auth().signInWithCustomToken(firebaseJWT).catch(function(error) {
            console.log('Error authenticating Firebase user. Code: ' + error.code + ' Message: ' + error.message);            
        });

但是从 Firebase 得到一个错误说：

Error authenticating Firebase user. Code: auth/invalid-custom-token Message: The custom token format is incorrect. Please check the documentation.

尝试添加不同的令牌过期控制声明也无济于事。

我还尝试使用 "dvsekhvalnov/jose-jwt" 库生成令牌，但无法使用 "RS256" 算法。

所以问题：

对我做错了什么有什么建议吗？

Answer 1

到目前为止还没有找到问题的直接答案，所以现在最终得到以下解决方案：

Using instruction here 生成了一个包含服务帐户详细信息的 JSON 文件，并使用 Firebase 服务器 SDK 创建了一个基本的 Node.js 服务器，它使用以下代码为 Firebase 生成正确的自定义令牌：

var http = require('http');
var httpdispatcher = require('httpdispatcher');
var firebase = require('firebase');

var config = {
    serviceAccount: {
    projectId: "{projectId}",
    clientEmail: "{projectServiceEmail}",
    privateKey: "-----BEGIN PRIVATE KEY----- ... ---END PRIVATE KEY-----\n"
  },
  databaseURL: "https://{projectId}.firebaseio.com"
};

firebase.initializeApp(config);    

const PORT=8080; 

httpdispatcher.onGet("/firebaseCustomToken", function(req, res) {
    var uid = req.params.uid;

    if (uid) {
        var customToken = firebase.auth().createCustomToken(uid);
        res.writeHead(200, {'Content-Type': 'application/json'});
        res.end(JSON.stringify({'firebaseJWT' : customToken}));
    } else {
        res.writeHead(400, {'Content-Type': 'text/plain'});
        res.end('No uid parameter specified');
    }
});    

function handleRequest(request, response){
     try {
        //log the request on console
        console.log(request.url);
        //Disptach
        httpdispatcher.dispatch(request, response);
    } catch(err) {
        console.log(err);
    }    
}

//create a server
var server = http.createServer(handleRequest);

//start our server
server.listen(PORT, function(){       
    console.log("Server listening on: http://localhost:%s", PORT);
});

也许有人会觉得这有帮助。

Answer 2

这个纯 .NET 解决方案适用于我，使用 Org.BouncyCastle (https://www.nuget.org/packages/BouncyCastle/) and Jose.JWT (https://www.nuget.org/packages/jose-jwt/) 库。

我遵循了这些步骤：

在 Firebase 控制台中，单击左上角项目名称旁边的 'cog' 图标，然后单击 'Permissions'。
在 IAM 和管理页面，单击左侧的 'Service Accounts'
点击上方的'Create Service Account'，在selection中输入'Service Account Name'、select、'Project->Editor'，勾选'Furnish a new private key'复选框和 select JSON
单击 'Create' 并下载服务帐户 JSON 文件并妥善保管。

在合适的文本编辑器中打开服务帐户 JSON 文件并将值放入以下代码中：

// private_key from the Service Account JSON file
public static string firebasePrivateKey=@"-----BEGIN PRIVATE KEY-----\nMIIE...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n...\n-----END PRIVATE KEY-----\n";

// Same for everyone
public static string firebasePayloadAUD="https://identitytoolkit.googleapis.com/google.identity.identitytoolkit.v1.IdentityToolkit";

// client_email from the Service Account JSON file
public static string firebasePayloadISS="serviceaccountname@projectname.iam.gserviceaccount.com";
public static string firebasePayloadSUB="serviceaccountname@projectname.iam.gserviceaccount.com";

// the token 'exp' - max 3600 seconds - see https://firebase.google.com/docs/auth/server/create-custom-tokens
public static int firebaseTokenExpirySecs=3600;

private static RsaPrivateCrtKeyParameters _rsaParams;
private static object _rsaParamsLocker=new object();

void Main() {
    // Example with custom claims
    var uid="myuserid";
    var claims=new Dictionary<string, object> {
        {"premium_account", true}
    };
    Console.WriteLine(EncodeToken(uid, claims));
}

public static string EncodeToken(string uid, Dictionary<string, object> claims) {
    // Get the RsaPrivateCrtKeyParameters if we haven't already determined them
    if (_rsaParams == null) {
        lock (_rsaParamsLocker) {
            if (_rsaParams == null) {
                StreamReader sr = new StreamReader(GenerateStreamFromString(firebasePrivateKey.Replace(@"\n","\n")));
                var pr = new Org.BouncyCastle.OpenSsl.PemReader(sr);
                _rsaParams = (RsaPrivateCrtKeyParameters)pr.ReadObject();
            }
        }
    }

    var payload = new Dictionary<string, object> {
        {"claims", claims}
        ,{"uid", uid}
        ,{"iat", secondsSinceEpoch(DateTime.UtcNow)}
        ,{"exp", secondsSinceEpoch(DateTime.UtcNow.AddSeconds(firebaseTokenExpirySecs))}
        ,{"aud", firebasePayloadAUD}
        ,{"iss", firebasePayloadISS}
        ,{"sub", firebasePayloadSUB}
    };

    return Jose.JWT.Encode(payload, Org.BouncyCastle.Security.DotNetUtilities.ToRSA(_rsaParams), JwsAlgorithm.RS256);
}

private static long secondsSinceEpoch(DateTime dt) {
    TimeSpan t = dt - new DateTime(1970, 1, 1);
    return (long)t.TotalSeconds;
}

private static Stream GenerateStreamFromString(string s) {
    MemoryStream stream = new MemoryStream();
    StreamWriter writer = new StreamWriter(stream);
    writer.Write(s);
    writer.Flush();
    stream.Position = 0;
    return stream;
}

为了使它在 IIS 中工作，我需要更改应用程序的池标识并将 "load user profile" 设置设置为 true。

Answer 3

@Elliveny 的回答对我很有效。我在 .NET Core 2.0 应用程序中使用它，并在已接受的答案的基础上将此解决方案转变为 class，可以在应用程序服务容器中注册为单例依赖项，并传入配置通过构造函数，以便我们可以利用 .NET 机密进行本地开发配置和环境变量进行生产配置。

我也整理了一下流处理。

.NET Core 开发人员注意事项 - 您需要使用 Portable.BouncyCastle

您可以通过使用 Jwt.IO

解析输出 JWT 令牌来测试编码结果

using Jose;
using Org.BouncyCastle.Crypto.Parameters;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

public class FirebaseTokenGenerator
{
    // private_key from the Service Account JSON file
    public static string firebasePrivateKey;

    // Same for everyone
    public static string firebasePayloadAUD = "https://identitytoolkit.googleapis.com/google.identity.identitytoolkit.v1.IdentityToolkit";

    // client_email from the Service Account JSON file
    public static string firebasePayloadISS;
    public static string firebasePayloadSUB;

    // the token 'exp' - max 3600 seconds - see https://firebase.google.com/docs/auth/server/create-custom-tokens
    public static int firebaseTokenExpirySecs = 3600;

    private static RsaPrivateCrtKeyParameters _rsaParams;
    private static object _rsaParamsLocker = new object();

    public FirebaseTokenGenerator(string privateKey, string clientEmail)
    {
        firebasePrivateKey = privateKey ?? throw new ArgumentNullException(nameof(privateKey));
        firebasePayloadISS = clientEmail ?? throw new ArgumentNullException(nameof(clientEmail));
        firebasePayloadSUB = clientEmail;
    }

    public static string EncodeToken(string uid)
    {
        return EncodeToken(uid, null);
    }

    public static string EncodeToken(string uid, Dictionary<string, object> claims)
    {
        // Get the RsaPrivateCrtKeyParameters if we haven't already determined them
        if (_rsaParams == null)
        {
            lock (_rsaParamsLocker)
            {
                if (_rsaParams == null)
                {
                    using (var streamWriter = WriteToStreamWithString(firebasePrivateKey.Replace(@"\n", "\n")))
                    {
                        using (var sr = new StreamReader(streamWriter.BaseStream))
                        {
                            var pr = new Org.BouncyCastle.OpenSsl.PemReader(sr);
                            _rsaParams = (RsaPrivateCrtKeyParameters)pr.ReadObject();
                        }
                    }
                }
            }
        }

        var payload = new Dictionary<string, object> {
        {"uid", uid}
        ,{"iat", SecondsSinceEpoch(DateTime.UtcNow)}
        ,{"exp", SecondsSinceEpoch(DateTime.UtcNow.AddSeconds(firebaseTokenExpirySecs))}
        ,{"aud", firebasePayloadAUD}
        ,{"iss", firebasePayloadISS}
        ,{"sub", firebasePayloadSUB}
    };

        if (claims != null && claims.Any())
        {
            payload.Add("claims", claims);
        }

        return JWT.Encode(payload, Org.BouncyCastle.Security.DotNetUtilities.ToRSA(_rsaParams), JwsAlgorithm.RS256);
    }


    private static long SecondsSinceEpoch(DateTime dt)
    {
        TimeSpan t = dt - new DateTime(1970, 1, 1);
        return (long) t.TotalSeconds;
    }

    private static StreamWriter WriteToStreamWithString(string s)
    {
        MemoryStream stream = new MemoryStream();
        StreamWriter writer = new StreamWriter(stream);
        writer.Write(s);
        writer.Flush();
        stream.Position = 0;
        return writer;
    }
}

Answer 4

@Elliveny 的代码在本地对我有用，但在天蓝色中会抛出错误："The system cannot find the file specified"。由于我稍微更改了代码，现在可以在两台服务器上使用了。

private string EncodeToken(string uid, Dictionary<string, object> claims)
    {

        string jwt = string.Empty;
        RsaPrivateCrtKeyParameters _rsaParams;

        using (StreamReader sr = new StreamReader(GenerateStreamFromString(private_key.Replace(@"\n", "\n"))))
        {
            var pr = new Org.BouncyCastle.OpenSsl.PemReader(sr);
            _rsaParams = (RsaPrivateCrtKeyParameters)pr.ReadObject();
        }


        using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())
        {
            Dictionary<string, object> payload = new Dictionary<string, object> {
                {"claims", claims}
                ,{"uid", uid}
                ,{"iat", secondsSinceEpoch(DateTime.UtcNow)}
                ,{"exp", secondsSinceEpoch(DateTime.UtcNow.AddSeconds(firebaseTokenExpirySecs))}
                ,{"aud", firebasePayloadAUD}
                ,{"iss", client_email}
                ,{"sub", client_email}
            };

            RSAParameters rsaParams = DotNetUtilities.ToRSAParameters(_rsaParams);
            rsa.ImportParameters(rsaParams);
            jwt = JWT.Encode(payload, rsa, Jose.JwsAlgorithm.RS256);
        }

        return jwt;

    }

Firebase 3：使用 .net 和 C# 创建自定义身份验证令牌

Firebase 3: creating a custom authentication token using .net and c#

c#

asp.net-mvc

firebase

firebase-authentication