public byte[] SignHash (byte[] rgbHash, string str)
{
if (rgbHash == null)
throw new ArgumentNullException ("rgbHash");
#if NET_2_0
// Fx 2.0 defaults to the SHA-1
string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
#else
if (str == null)
throw new CryptographicException (Locale.GetText ("No OID specified"));
string hashName = GetHashNameFromOID (str);
#endif
HashAlgorithm hash = HashAlgorithm.Create (hashName);
return PKCS1.Sign_v15 (this, hash, rgbHash);
}