case Smb2Constants.SMB2_DIALECT_0302:
            signingKey = Smb3KeyDerivation.deriveSigningKey(dialect, sessionKey, new byte[0] /* unimplemented */);
            m = Mac.getInstance("AESCMAC", Crypto.getProvider());
            break;
        case Smb2Constants.SMB2_DIALECT_0311:
            if ( preauthIntegrityHash == null ) {
                throw new IllegalArgumentException("Missing preauthIntegrityHash for SMB 3.1");