public KeyParameter(
byte[] key,
int keyOff,
int keyLen)
{
if(key == null)
throw new ArgumentNullException("key");
if(keyOff < 0 || keyOff > key.Length)
throw new ArgumentOutOfRangeException("keyOff");
if(keyLen < 0 || (keyOff + keyLen) > key.Length)
throw new ArgumentOutOfRangeException("keyLen");
this.key = new byte[keyLen];
Array.Copy(key, keyOff, this.key, 0, keyLen);
}