class Program
{
    static string key = "401b09eab3c013d4ca54922bb802bec8fd5318192b0a75f201d8b3727429090fb337591abd3e44453b954555b7a0812e1081c39b740293f765eae731f5a65ed1";

    static void Main(string[] args)
    {
        var stringToken = GenerateToken();
        ValidateToken(stringToken);
    }

    private static string GenerateToken()
    {
        var securityKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(key));
        var credentials = new SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256);

        var secToken = new JwtSecurityToken(
            signingCredentials: credentials,
            issuer: "Sample",
            audience: "Sample",
            claims: new[]
            {
                new Claim(JwtRegisteredClaimNames.Sub, "meziantou")
            },
            expires: DateTime.UtcNow.AddDays(1));

        var handler = new JwtSecurityTokenHandler();
        return handler.WriteToken(secToken);
    }

    private static bool ValidateToken(string authToken)
    {
        var tokenHandler = new JwtSecurityTokenHandler();
        var validationParameters = GetValidationParameters();

        SecurityToken validatedToken;
        IPrincipal principal = tokenHandler.ValidateToken(authToken, validationParameters, out validatedToken);
        return true;
    }

    private static TokenValidationParameters GetValidationParameters()
    {
        return new TokenValidationParameters()
        {
            ValidateLifetime = false, // Because there is no expiration in the generated token
            ValidateAudience = false, // Because there is no audiance in the generated token
            ValidateIssuer = false,   // Because there is no issuer in the generated token
            ValidIssuer = "Sample",
            ValidAudience = "Sample",
            IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(key)) // The same key as the one that generate the token
        };
    }
}