C# 中是否有任何 JSON Web 令牌 (JWT) 示例

本文关键字:令牌 JWT 示例 Web JSON 是否 任何 | 更新日期: 2023-09-27 18:30:32

我觉得我在这里吃了疯狂的药。通常,对于任何给定的任务,网络上总有一百万个库和样本。我正在尝试使用 JSON Web 令牌 (JWT) 通过 Google "服务帐户"实现身份验证,如此处所述。

但是,只有PHP,Python和Java中的客户端库。即使在谷歌身份验证之外搜索 JWT 示例,也只有 JWT 概念上的蟋蟀和草稿。这真的是那么新,可能是谷歌专有的系统吗?

我能解释的最接近的 java 示例看起来非常密集且令人生畏。C#中一定有一些东西,我至少可以从开始。对此的任何帮助都会很棒!

C# 中是否有任何 JSON Web 令牌 (JWT) 示例

我找到了Json Web Token的基本实现,并用Google风格对其进行了扩展。我还没有完全解决它,但它在那里有 97%。这个项目失去了动力,所以希望这能帮助其他人获得良好的开端:

注意:我对基本实现所做的更改(不记得在哪里找到它)是:

  1. 更改 HS256 -> RS256
  2. 交换了标头中的 JWT 和 alg 顺序。不确定谁弄错了,谷歌或规范,但谷歌根据他们的文档采取
  3. 的方式如下。
public enum JwtHashAlgorithm
{
    RS256,
    HS384,
    HS512
}
    
public class JsonWebToken
{
    private static Dictionary<JwtHashAlgorithm, Func<byte[], byte[], byte[]>> HashAlgorithms;
    static JsonWebToken()
    {
        HashAlgorithms = new Dictionary<JwtHashAlgorithm, Func<byte[], byte[], byte[]>>
            {
                { JwtHashAlgorithm.RS256, (key, value) => { using (var sha = new HMACSHA256(key)) { return sha.ComputeHash(value); } } },
                { JwtHashAlgorithm.HS384, (key, value) => { using (var sha = new HMACSHA384(key)) { return sha.ComputeHash(value); } } },
                { JwtHashAlgorithm.HS512, (key, value) => { using (var sha = new HMACSHA512(key)) { return sha.ComputeHash(value); } } }
            };
    }
    public static string Encode(object payload, string key, JwtHashAlgorithm algorithm)
    {
        return Encode(payload, Encoding.UTF8.GetBytes(key), algorithm);
    }
    public static string Encode(object payload, byte[] keyBytes, JwtHashAlgorithm algorithm)
    {
        var segments = new List<string>();
        var header = new { alg = algorithm.ToString(), typ = "JWT" };
        byte[] headerBytes = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(header, Formatting.None));
        byte[] payloadBytes = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(payload, Formatting.None));
        //byte[] payloadBytes = Encoding.UTF8.GetBytes(@"{"iss":"761326798069-r5mljlln1rd4lrbhg75efgigp36m78j5@developer.gserviceaccount.com","scope":"https://www.googleapis.com/auth/prediction","aud":"https://accounts.google.com/o/oauth2/token","exp":1328554385,"iat":1328550785}");
        segments.Add(Base64UrlEncode(headerBytes));
        segments.Add(Base64UrlEncode(payloadBytes));
        var stringToSign = string.Join(".", segments.ToArray());
        var bytesToSign = Encoding.UTF8.GetBytes(stringToSign);
        byte[] signature = HashAlgorithms[algorithm](keyBytes, bytesToSign);
        segments.Add(Base64UrlEncode(signature));
        return string.Join(".", segments.ToArray());
    }
    public static string Decode(string token, string key)
    {
        return Decode(token, key, true);
    }
    public static string Decode(string token, string key, bool verify)
    {
        var parts = token.Split('.');
        var header = parts[0];
        var payload = parts[1];
        byte[] crypto = Base64UrlDecode(parts[2]);
        var headerJson = Encoding.UTF8.GetString(Base64UrlDecode(header));
        var headerData = JObject.Parse(headerJson);
        var payloadJson = Encoding.UTF8.GetString(Base64UrlDecode(payload));
        var payloadData = JObject.Parse(payloadJson);
        if (verify)
        {
            var bytesToSign = Encoding.UTF8.GetBytes(string.Concat(header, ".", payload));
            var keyBytes = Encoding.UTF8.GetBytes(key);
            var algorithm = (string)headerData["alg"];
            var signature = HashAlgorithms[GetHashAlgorithm(algorithm)](keyBytes, bytesToSign);
            var decodedCrypto = Convert.ToBase64String(crypto);
            var decodedSignature = Convert.ToBase64String(signature);
            if (decodedCrypto != decodedSignature)
            {
                throw new ApplicationException(string.Format("Invalid signature. Expected {0} got {1}", decodedCrypto, decodedSignature));
            }
        }
        return payloadData.ToString();
    }
    private static JwtHashAlgorithm GetHashAlgorithm(string algorithm)
    {
        switch (algorithm)
        {
            case "RS256": return JwtHashAlgorithm.RS256;
            case "HS384": return JwtHashAlgorithm.HS384;
            case "HS512": return JwtHashAlgorithm.HS512;
            default: throw new InvalidOperationException("Algorithm not supported.");
        }
    }
    // from JWT spec
    private static string Base64UrlEncode(byte[] input)
    {
        var output = Convert.ToBase64String(input);
        output = output.Split('=')[0]; // Remove any trailing '='s
        output = output.Replace('+', '-'); // 62nd char of encoding
        output = output.Replace('/', '_'); // 63rd char of encoding
        return output;
    }
    // from JWT spec
    private static byte[] Base64UrlDecode(string input)
    {
        var output = input;
        output = output.Replace('-', '+'); // 62nd char of encoding
        output = output.Replace('_', '/'); // 63rd char of encoding
        switch (output.Length % 4) // Pad with trailing '='s
        {
            case 0: break; // No pad chars in this case
            case 2: output += "=="; break; // Two pad chars
            case 3: output += "="; break; // One pad char
            default: throw new System.Exception("Illegal base64url string!");
        }
        var converted = Convert.FromBase64String(output); // Standard base64 decoder
        return converted;
    }
}

然后是我的谷歌特定的 JWT 类:

public class GoogleJsonWebToken
{
    public static string Encode(string email, string certificateFilePath)
    {
        var utc0 = new DateTime(1970,1,1,0,0,0,0, DateTimeKind.Utc);
        var issueTime = DateTime.Now;
        var iat = (int)issueTime.Subtract(utc0).TotalSeconds;
        var exp = (int)issueTime.AddMinutes(55).Subtract(utc0).TotalSeconds; // Expiration time is up to 1 hour, but lets play on safe side
        var payload = new
        {
            iss = email,
            scope = "https://www.googleapis.com/auth/gan.readonly",
            aud = "https://accounts.google.com/o/oauth2/token",
            exp = exp,
            iat = iat
        };
        var certificate = new X509Certificate2(certificateFilePath, "notasecret");
        var privateKey = certificate.Export(X509ContentType.Cert);
        return JsonWebToken.Encode(payload, privateKey, JwtHashAlgorithm.RS256);
    }
}

我从未使用过它,但是NuGet上有一个JWT实现。

包装:https://nuget.org/packages/JWT

来源: https://github.com/johnsheehan/jwt

兼容 .NET 4.0:https://www.nuget.org/packages/jose-jwt/

您也可以转到此处:https://jwt.io/然后单击"库"。

这是我

在.NET中实现的(Google)JWT验证。它基于Stack Overflow和GitHub gist上的其他实现。

using Microsoft.IdentityModel.Tokens;
using System;
using System.Collections.Generic;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Net.Http;
using System.Security.Claims;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Threading.Tasks;
namespace QuapiNet.Service
{
    public class JwtTokenValidation
    {
        public async Task<Dictionary<string, X509Certificate2>> FetchGoogleCertificates()
        {
            using (var http = new HttpClient())
            {
                var response = await http.GetAsync("https://www.googleapis.com/oauth2/v1/certs");
                var dictionary = await response.Content.ReadAsAsync<Dictionary<string, string>>();
                return dictionary.ToDictionary(x => x.Key, x => new X509Certificate2(Encoding.UTF8.GetBytes(x.Value)));
            }
        }
        private string CLIENT_ID = "xxx.apps.googleusercontent.com";
        public async Task<ClaimsPrincipal> ValidateToken(string idToken)
        {
            var certificates = await this.FetchGoogleCertificates();
            TokenValidationParameters tvp = new TokenValidationParameters()
            {
                ValidateActor = false, // check the profile ID
                ValidateAudience = true, // check the client ID
                ValidAudience = CLIENT_ID,
                ValidateIssuer = true, // check token came from Google
                ValidIssuers = new List<string> { "accounts.google.com", "https://accounts.google.com" },
                ValidateIssuerSigningKey = true,
                RequireSignedTokens = true,
                IssuerSigningKeys = certificates.Values.Select(x => new X509SecurityKey(x)),
                IssuerSigningKeyResolver = (token, securityToken, kid, validationParameters) =>
                {
                    return certificates
                    .Where(x => x.Key.ToUpper() == kid.ToUpper())
                    .Select(x => new X509SecurityKey(x.Value));
                },
                ValidateLifetime = true,
                RequireExpirationTime = true,
                ClockSkew = TimeSpan.FromHours(13)
            };
            JwtSecurityTokenHandler jsth = new JwtSecurityTokenHandler();
            SecurityToken validatedToken;
            ClaimsPrincipal cp = jsth.ValidateToken(idToken, tvp, out validatedToken);
            return cp;
        }
    }
}

请注意,为了使用它,您需要添加对 NuGet 包System.Net.Http.Formatting.Extension的引用。否则,编译器将无法识别ReadAsAsync<>方法。

最好使用标准库和著名库,而不是从头开始编写代码。

  1. 用于编码和解码 JWT 令牌的 JWT
  2. 充气城堡支持加密和解密,尤其是RS256在这里得到它

使用这些库,您可以生成 JWT 令牌并使用 RS256 对其进行签名,如下所示。

public string GenerateJWTToken(string rsaPrivateKey)
{
    var rsaParams = GetRsaParameters(rsaPrivateKey);
    var encoder = GetRS256JWTEncoder(rsaParams);
    // create the payload according to the Google's doc
    var payload = new Dictionary<string, object>
    {
        { "iss", ""},
        { "sub", "" },
        // and other key-values according to the doc
    };
    // add headers. 'alg' and 'typ' key-values are added automatically.
    var header = new Dictionary<string, object>
    {
        { "kid", "{your_private_key_id}" },
    };
    var token = encoder.Encode(header,payload, new byte[0]);
    return token;
}
private static IJwtEncoder GetRS256JWTEncoder(RSAParameters rsaParams)
{
    var csp = new RSACryptoServiceProvider();
    csp.ImportParameters(rsaParams);
    var algorithm = new RS256Algorithm(csp, csp);
    var serializer = new JsonNetSerializer();
    var urlEncoder = new JwtBase64UrlEncoder();
    var encoder = new JwtEncoder(algorithm, serializer, urlEncoder);
    return encoder;
}
private static RSAParameters GetRsaParameters(string rsaPrivateKey)
{
    var byteArray = Encoding.ASCII.GetBytes(rsaPrivateKey);
    using (var ms = new MemoryStream(byteArray))
    {
        using (var sr = new StreamReader(ms))
        {
            // use Bouncy Castle to convert the private key to RSA parameters
            var pemReader = new PemReader(sr);
            var keyPair = pemReader.ReadObject() as AsymmetricCipherKeyPair;
            return DotNetUtilities.ToRSAParameters(keyPair.Private as RsaPrivateCrtKeyParameters);
        }
    }
}

ps:RSA 私钥应具有以下格式:

-----BEGIN RSA PRIVATE KEY-----
 {base64 formatted value}
-----END RSA PRIVATE KEY-----

这是另一个仅 REST 的工作示例,用于访问 G Suite 用户和群组的 Google 服务帐户,通过 JWT 进行身份验证。这只能通过 Google 库的反射来实现,因为 Google 对这些 API 的文档非常糟糕。任何习惯于用MS技术编码的人都很难弄清楚Google服务中所有内容是如何结合在一起的。

$iss = "<name>@<serviceaccount>.iam.gserviceaccount.com"; # The email address of the service account.
$sub = "impersonate.user@mydomain.com"; # The user to impersonate (required).
$scope = "https://www.googleapis.com/auth/admin.directory.user.readonly https://www.googleapis.com/auth/admin.directory.group.readonly";
$certPath = "D:'temp'mycertificate.p12";
$grantType = "urn:ietf:params:oauth:grant-type:jwt-bearer";
# Auxiliary functions
function UrlSafeEncode([String] $Data) {
    return $Data.Replace("=", [String]::Empty).Replace("+", "-").Replace("/", "_");
}
function UrlSafeBase64Encode ([String] $Data) {
    return (UrlSafeEncode -Data ([Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($Data))));
}
function KeyFromCertificate([System.Security.Cryptography.X509Certificates.X509Certificate2] $Certificate) {
    $privateKeyBlob = $Certificate.PrivateKey.ExportCspBlob($true);
    $key = New-Object System.Security.Cryptography.RSACryptoServiceProvider;
    $key.ImportCspBlob($privateKeyBlob);
    return $key;
}
function CreateSignature ([Byte[]] $Data, [System.Security.Cryptography.X509Certificates.X509Certificate2] $Certificate) {
    $sha256 = [System.Security.Cryptography.SHA256]::Create();
    $key = (KeyFromCertificate $Certificate);
    $assertionHash = $sha256.ComputeHash($Data);
    $sig = [Convert]::ToBase64String($key.SignHash($assertionHash, "2.16.840.1.101.3.4.2.1"));
    $sha256.Dispose();
    return $sig;
}
function CreateAssertionFromPayload ([String] $Payload, [System.Security.Cryptography.X509Certificates.X509Certificate2] $Certificate) {
    $header = @"
{"alg":"RS256","typ":"JWT"}
"@;
    $assertion = New-Object System.Text.StringBuilder;
    $assertion.Append((UrlSafeBase64Encode $header)).Append(".").Append((UrlSafeBase64Encode $Payload)) | Out-Null;
    $signature = (CreateSignature -Data ([System.Text.Encoding]::ASCII.GetBytes($assertion.ToString())) -Certificate $Certificate);
    $assertion.Append(".").Append((UrlSafeEncode $signature)) | Out-Null;
    return $assertion.ToString();
}
$baseDateTime = New-Object DateTime(1970, 1, 1, 0, 0, 0, [DateTimeKind]::Utc);
$timeInSeconds = [Math]::Truncate([DateTime]::UtcNow.Subtract($baseDateTime).TotalSeconds);
$jwtClaimSet = @"
{"scope":"$scope","email_verified":false,"iss":"$iss","sub":"$sub","aud":"https://oauth2.googleapis.com/token","exp":$($timeInSeconds + 3600),"iat":$timeInSeconds}
"@;

$cert = New-Object System.Security.Cryptography.X509Certificates.X509Certificate2($certPath, "notasecret", [System.Security.Cryptography.X509Certificates.X509KeyStorageFlags]::Exportable);
$jwt = CreateAssertionFromPayload -Payload $jwtClaimSet -Certificate $cert;

# Retrieve the authorization token.
$authRes = Invoke-WebRequest -Uri "https://oauth2.googleapis.com/token" -Method Post -ContentType "application/x-www-form-urlencoded" -UseBasicParsing -Body @"
assertion=$jwt&grant_type=$([Uri]::EscapeDataString($grantType))
"@;
$authInfo = ConvertFrom-Json -InputObject $authRes.Content;
$resUsers = Invoke-WebRequest -Uri "https://www.googleapis.com/admin/directory/v1/users?domain=<required_domain_name_dont_trust_google_documentation_on_this>" -Method Get -Headers @{
    "Authorization" = "$($authInfo.token_type) $($authInfo.access_token)"
}
$users = ConvertFrom-Json -InputObject $resUsers.Content;
$users.users | ft primaryEmail, isAdmin, suspended;

以下是类和函数的列表:

open System
open System.Collections.Generic
open System.Linq
open System.Threading.Tasks
open Microsoft.AspNetCore.Mvc
open Microsoft.Extensions.Logging
open Microsoft.AspNetCore.Authorization
open Microsoft.AspNetCore.Authentication
open Microsoft.AspNetCore.Authentication.JwtBearer
open Microsoft.IdentityModel.Tokens
open System.IdentityModel.Tokens
open System.IdentityModel.Tokens.Jwt
open Microsoft.IdentityModel.JsonWebTokens
open System.Text
open Newtonsoft.Json
open System.Security.Claims
    let theKey = "VerySecretKeyVerySecretKeyVerySecretKey"
    let securityKey = SymmetricSecurityKey(Encoding.UTF8.GetBytes(theKey))
    let credentials = SigningCredentials(securityKey, SecurityAlgorithms.RsaSsaPssSha256)
    let expires = DateTime.UtcNow.AddMinutes(123.0) |> Nullable
    let token = JwtSecurityToken(
                    "lahoda-pro-issuer", 
                    "lahoda-pro-audience",
                    claims = null,
                    expires =  expires,
                    signingCredentials = credentials
        )
    let tokenString = JwtSecurityTokenHandler().WriteToken(token)

使用System.Security.Cryptography.RSA,我修改了John Sheehan的JWT库代码,该代码由@Levitikon扩展为使用RS256RSASSA-PKCS1-v1_5 with the SHA-256 hash algorithm

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.Text;
/// <summary>
/// adapted from<br/>
/// https://github.com/jwt-dotnet/jwt<br/>
/// https://stackoverflow.com/questions/10055158/is-there-any-json-web-token-jwt-example-in-c<br/>
/// https://stackoverflow.com/a/10106800/6620171<br/>
/// <br/>
/// JSON Web Token (JWT) is a compact, URL-safe means of representing<br/>
/// claims to be transferred between two parties.  The claims in a JWT<br/>
/// are encoded as a JSON object that is used as the payload of a JSON<br/>
/// Web Signature (JWS) structure or as the plaintext of a JSON Web<br/>
/// Encryption(JWE) structure, enabling the claims to be digitally<br/>
/// signed or integrity protected with a Message Authentication Code<br/>
/// (MAC) and/or encrypted.<br/>
/// <br/>
/// https://www.rfc-editor.org/rfc/rfc7519
/// </summary>
internal class JsonWebToken
{
    /// <summary>
    /// JWS uses cryptographic algorithms to digitally sign or create a MAC<br/>
    /// of the contents of the JWS Protected Header and the JWS Payload.<br/>
    /// <br/>
    /// https://www.rfc-editor.org/rfc/rfc7518#section-3
    /// </summary>
    public enum JwsAlgorythm
    {
        /// <summary>
        /// RSASSA-PKCS1-v1_5 using SHA-256<br/>
        /// This section defines the use of the RSASSA-PKCS1-v1_5 digital<br/>
        /// signature algorithm as defined in Section 8.2 of RFC 3447 [RFC3447]<br/>
        /// (commonly known as PKCS #1), using SHA-2 [SHS] hash functions.<br/>
        /// The RSASSA-PKCS1-v1_5 SHA-256 digital signature is generated as<br/>
        /// follows: generate a digital signature of the JWS Signing Input using<br/>
        /// RSASSA-PKCS1-v1_5-SIGN and the SHA-256 hash function with the desired<br/>
        /// private key.  This is the JWS Signature value.<br/>
        /// <br/>
        /// https://www.rfc-editor.org/rfc/rfc7518#section-3.3<br/>
        /// https://www.rfc-editor.org/rfc/rfc3447#section-8.2<br/>
        /// https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf
        /// </summary>
        RS256,
        /// <summary>
        /// No digital signature or MAC performed<br/>
        /// JWSs MAY also be created that do not provide integrity protection.<br/>
        /// Such a JWS is called an Unsecured JWS.  An Unsecured JWS uses the<br/>
        /// "alg" value "none" and is formatted identically to other JWSs, but<br/>
        /// MUST use the empty octet sequence as its JWS Signature value.<br/>
        /// Recipients MUST verify that the JWS Signature value is the empty<br/>
        /// octet sequence.<br/>
        /// <br/>
        /// https://www.rfc-editor.org/rfc/rfc7518#section-3.6<br/>
        /// https://www.rfc-editor.org/rfc/rfc7519#section-6
        /// </summary>
        none
    }
    public static string Encode(object payload, JwsAlgorythm algo, RSA rsa)
    {
        if (payload == null) { throw new ArgumentNullException("payload"); }
        if (algo != JwsAlgorythm.RS256 && algo != JwsAlgorythm.none) { throw new ArgumentException("Invalid JwsAlgorythm specified"); }
        if (rsa == null && algo == JwsAlgorythm.RS256) { throw new ArgumentNullException("Encoding of secured JWT requires an RSA object"); }
        List<string> segments = new List<string>();
        var header = new { typ = "JWT", alg = algo.ToString() };
        string strHeader = JsonConvert.SerializeObject(header, Formatting.None);
        string strPayload = JsonConvert.SerializeObject(payload, Formatting.None);
        byte[] headerBytes = Encoding.UTF8.GetBytes(strHeader);
        byte[] payloadBytes = Encoding.UTF8.GetBytes(strPayload);
        segments.Add(Base64UrlEncode(headerBytes));
        segments.Add(Base64UrlEncode(payloadBytes));
        if (algo == JwsAlgorythm.none)
        {
            segments.Add(string.Empty);
            return string.Join(".", segments.ToArray());
        }
        string stringToSign = string.Join(".", segments.ToArray());
        byte[] bytesToSign = Encoding.UTF8.GetBytes(stringToSign);
        byte[] signature = rsa.SignData(bytesToSign, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
        segments.Add(Base64UrlEncode(signature));
        return string.Join(".", segments.ToArray());
    }
    public static Tuple<string, string> Decode(string token, JwsAlgorythm algo, bool verify, RSA rsa = null)
    {
        if (algo != JwsAlgorythm.RS256 && algo != JwsAlgorythm.none) { throw new ArgumentException("Invalid JwsAlgorythm specified"); }
        if (verify && rsa == null && algo == JwsAlgorythm.RS256) { throw new ArgumentNullException("Verification of secured JWT requires an RSA object"); }
        string[] parts = token.Split('.');
        string header = parts[0];
        string payload = parts[1];
        byte[] crypto = Base64UrlDecode(parts[2]);
        string headerJson = Encoding.UTF8.GetString(Base64UrlDecode(header));
        JObject headerData = JObject.Parse(headerJson);
        string payloadJson = Encoding.UTF8.GetString(Base64UrlDecode(payload));
        JObject payloadData = JObject.Parse(payloadJson);
        if (verify)
        {
            if (algo == JwsAlgorythm.none)
            {
                if (crypto.Length != 0)
                {
                    throw new ApplicationException(string.Format("Invalid signature"));
                }
            }
            else if (algo == JwsAlgorythm.RS256)
            {
                byte[] bytesToSign = Encoding.UTF8.GetBytes(string.Concat(header, ".", payload));
                bool valid = rsa.VerifyData(bytesToSign, crypto, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
                if (!valid)
                {
                    throw new ApplicationException(string.Format("Invalid signature"));
                }
            }
        }
        return new Tuple<string, string>(headerData.ToString(), payloadData.ToString());
    }
    // from JWT spec
    private static string Base64UrlEncode(byte[] input)
    {
        string output = Convert.ToBase64String(input);
        output = output.Split('=')[0]; // Remove any trailing '='s
        output = output.Replace('+', '-'); // 62nd char of encoding
        output = output.Replace('/', '_'); // 63rd char of encoding
        return output;
    }
    // from JWT spec
    private static byte[] Base64UrlDecode(string input)
    {
        string output = input;
        output = output.Replace('-', '+'); // 62nd char of encoding
        output = output.Replace('_', '/'); // 63rd char of encoding
        switch (output.Length % 4) // Pad with trailing '='s
        {
            case 0: break; // No pad chars in this case
            case 2: output += "=="; break; // Two pad chars
            case 3: output += "="; break; // One pad char
            default: throw new Exception("Invalid base64url string");
        }
        byte[] converted = Convert.FromBase64String(output); // Standard base64 decoder
        return converted;
    }
}

用法:

X509Certificate2 cert = new X509Certificate2("C:''test''keypair.pfx", "notasecret");
long secsSinceEpoch = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
var jwt = new
{
    exp = secsSinceEpoch + 600,
    iss = "my client id",
    aud = "h++ps://webapi.com",
    sub = "my subscriber id",
    iat = secsSinceEpoch,
    nbf = secsSinceEpoch,
    jti = RandomString(21),
};
string jwtEncoded = JsonWebToken.Encode(jwt, JsonWebToken.JwsAlgorythm.RS256, cert.GetRSAPrivateKey());
Tuple<string, string> jwtDecoded = JsonWebToken.Decode(jwtEncoded, JsonWebToken.JwsAlgorythm.RS256, true, cert.GetRSAPublicKey());
Console.WriteLine(jwtDecoded);

输出:

({
  "typ": "JWT",
  "alg": "RS256"
}, {
  "exp": 1668732075,
  "iss": "my client id",
  "aud": "h++ps://webapi.com",
  "sub": "my subscriber id",
  "iat": 1668731475,
  "nbf": 1668731475,
  "jti": "tCUpk2i5bNBVBcj7LzV5U"
})