using System;

using Microsoft.IdentityModel.Tokens;

using System.IdentityModel.Tokens.Jwt;

using System.Security.Claims;

using System.Text;

public class Program

{

    public static string generateToken(string secret_key){;

​

        var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(secret_key));

        var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);

​

        var token = new JwtSecurityToken(

            expires: DateTime.Now.AddMinutes(5), // Token expires in 5 minutes,To Test Expiry DateTime.Now.AddMinutes(-1)

            signingCredentials: creds

        );

        var t = new JwtSecurityTokenHandler().WriteToken(token);

        return t;

    }

    public static bool validateToken(string token,string secret_key){

    try{

        var tokenValidationParameters = new TokenValidationParameters

            {

                ValidateIssuer = false, // Set to true if you want to validate the issuer

                ValidateAudience = false, // Set to true if you want to validate the audience

                ValidateLifetime = true, // Set to true if you want to validate the expiration

                IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(secret_key))

            };

​

            // Create a token handler

            var tokenHandler = new JwtSecurityTokenHandler();

​

            // Decode and validate the token

            ClaimsPrincipal claimsPrincipal = tokenHandler.ValidateToken(token, tokenValidationParameters, out SecurityToken validatedToken);

            long d = long.Parse(claimsPrincipal.FindFirst("exp").Value);

            DateTime expiryDate = DateTimeOffset.FromUnixTimeSeconds(d).DateTime;

            if(expiryDate < DateTime.Now){

                throw new SecurityTokenException("Token has expired");

            }

            // Access the claims

            foreach (Claim claim in claimsPrincipal.Claims)

            {

                Console.WriteLine($"{claim.Type}: {claim.Value}");

            }

            return true;

        }

        catch (SecurityTokenException ex)

        {

            Console.WriteLine($"Token validation failed: {ex.Message}");

            return false;

        }

    }

    public static void Main()

    {

        var secretKey = "2cd3d0b0-284a-403f-8654-1ddae2f775fb"; // Any Uniqie Identifier

        string token = generateToken(secretKey);

​

        Console.WriteLine("Token Is :"+token);

        Console.WriteLine("Is Token Valid :" + validateToken(token,secretKey));

    }

}