var validationParameters = new TokenValidationParameters
{
    RequireExpirationTime = true,
    RequireSignedTokens = true,
    ValidateIssuer = true,
    ValidIssuer = issuer,
    ValidateIssuerSigningKey = true,
    IssuerSigningKey = signingKey,
    ValidateAudience = true,
    ValidAudience = audience,
    ValidateLifetime = true,
    AuthenticationType = "ApplicationCookie"
};