public static int GenerateCode(SecurityToken securityToken, string modifier = null)
{
if (securityToken == null)
{
throw new ArgumentNullException("securityToken");
}
// Allow a variance of no greater than 90 seconds in either direction
var currentTimeStep = GetCurrentTimeStepNumber();
using (var hashAlgorithm = new HMACSHA1(securityToken.GetDataNoClone()))
{
return ComputeTotp(hashAlgorithm, currentTimeStep, modifier);
}
}
public static bool ValidateCode(SecurityToken securityToken, int code, string modifier = null)
{
if (securityToken == null)
{
throw new ArgumentNullException("securityToken");
}
// Allow a variance of no greater than 90 seconds in either direction
var currentTimeStep = GetCurrentTimeStepNumber();
using (var hashAlgorithm = new HMACSHA1(securityToken.GetDataNoClone()))
{
for (var i = -2; i <= 2; i++)
{
var computedTotp = ComputeTotp(hashAlgorithm, (ulong) ((long) currentTimeStep + i), modifier);
if (computedTotp == code)
{
return true;
}
}
}
// No match
return false;
}
