ASP.NET Core：验证Auth0的JWT令牌

Question

我正在使用Auth0并按如下方式解析其idToken服务器端：

    var tokenHandler = new JwtSecurityTokenHandler();
    var jwtToken = tokenHandler.ReadJwtToken(idToken); // idToken comes from client using auth0.js
    var sub = jwtToken.Claims.First(claim => claim.Type == "sub").Value;

上面的代码运行良好，我能够成功解析idToken，但是我想在信任idToken之前先对其进行验证，所以我尝试了此操作：

        string clientSecret = "{client_secret}"; // comes from Auth0 application's client secret
        var validations = new TokenValidationParameters
        {
            ValidateIssuer = true,
            ValidateAudience = true,
            ValidateIssuerSigningKey = true,
            ValidIssuer = "some value", // used "iss" from here: https://jwt.io/
            ValidAudience = "some value", // used "aud" from here: https://jwt.io/
            IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(clientSecret)),
        };

        var principal = tokenHandler.ValidateToken(idToken, validations, out var validatedToken);

[尝试验证令牌时，将导致此异常：

Microsoft.IdentityModel.Tokens.SecurityTokenSignatureKeyNotFoundException
  HResult=0x80131500
  Message=IDX10501: Signature validation failed. Unable to match key: 
kid: '[PII is hidden. For more details, see https://aka.ms/IdentityModel/PII.]'

我通过在此处解析其中一个令牌来获取发行者和受众的价值：https://jwt.io/。客户密码是我的应用程序在Auth0处的客户密码。

如何使用idToken验证Auth0的JwtSecurityTokenHandler？

Answer 1

要手动验证Auth0的JWT令牌，您需要以下2个Nuget软件包：

System.IdentityModel.Tokens.Jwt
Microsoft.IdentityModel.Protocols.OpenIdConnect

然后从Auth0的应用程序设置中获取这些值

string auth0Domain = ""; // Note: if your Domain is foo.auth0.com, this needs to be https://foo.auth0.com/
string auth0ClientId = "";

如下验证Auth0的令牌：

IConfigurationManager<OpenIdConnectConfiguration> configurationManager = new ConfigurationManager<OpenIdConnectConfiguration>($"{auth0Domain}.well-known/openid-configuration", new OpenIdConnectConfigurationRetriever());
OpenIdConnectConfiguration openIdConfig = await configurationManager.GetConfigurationAsync(CancellationToken.None);

var validations = new TokenValidationParameters
{
    ValidIssuer = auth0Domain,
    ValidAudiences = new[] { auth0ClientId },
    IssuerSigningKeys = openIdConfig.SigningKeys
};

var user = tokenHandler.ValidateToken(idToken, validations, out var validatedToken);

使用经过验证的令牌，您可以像这样提取有用的信息：

var securityToken = (JwtSecurityToken)validatedToken;
var userId = user.Claims.First(c => c.Type == ClaimTypes.NameIdentifier).Value;

来源：Manually validating a JWT using .NET

信用：@Nkosi