How to use the node-opcua-crypto.reduceLength function in node-opcua-crypto

// then verify the signature
    const signatureLength = cert.publicKeyLength; // 1024 bits = 128Bytes or 2048=256Bytes or 3072 or 4096
    assert(signatureLength === 128 || signatureLength === 256 || signatureLength === 384 || signatureLength === 512 );

    const chunk = binaryStream._buffer;

    const signatureIsOK = this.cryptoFactory.asymmetricVerifyChunk(chunk, this.securityHeader.senderCertificate);

    if (!signatureIsOK) {
        console.log(hexDump(binaryStream._buffer));
        this._report_error("SIGN and ENCRYPT asymmetricVerify : Invalid packet signature");
        return false;
    }

    // remove signature
    binaryStream._buffer = crypto_utils.reduceLength(binaryStream._buffer, signatureLength);

    // remove padding
    if (this.securityHeader.receiverCertificateThumbprint) {
        binaryStream._buffer = crypto_utils.removePadding(binaryStream._buffer);
    }

    return true; // success
};

debugLog(hexDump(binaryStream.buffer));
                debugLog(chalk.cyan("-------------------------------"));
            }
        }

        // now check signature ....
        const chunk = binaryStream.buffer;

        const signatureIsOK = verifyChunkSignatureWithDerivedKeys(chunk, derivedKeys);
        if (!signatureIsOK) {
            this._report_error("_decrypt_MSG : Sign and Encrypt : Invalid packet signature");
            return false;
        }

        // remove signature
        binaryStream.buffer = reduceLength(binaryStream.buffer, derivedKeys.signatureLength);

        if (this.securityMode === MessageSecurityMode.SignAndEncrypt) {
            // remove padding
            binaryStream.buffer = removePadding(binaryStream.buffer);
        }

        return true;
    }

const chunk = binaryStream.buffer;

        const signatureIsOK = asymmetricVerifyChunk(this.cryptoFactory, chunk, asymmetricAlgorithmSecurityHeader.senderCertificate);

        if (!signatureIsOK) {
            /* istanbul ignore next */
            if (doDebug) {
                debugLog(hexDump(binaryStream.buffer));
            }
            this._report_error("Sign and Encrypt asymmetricVerify : Invalid packet signature");
            return false;
        }

        // remove signature
        binaryStream.buffer = reduceLength(binaryStream.buffer, signatureLength);

        // remove padding
        if (asymmetricAlgorithmSecurityHeader.receiverCertificateThumbprint) {
            binaryStream.buffer = removePadding(binaryStream.buffer);
        }

        return true; // success
    }

debugLog(hexDump(binaryStream._buffer));
            debugLog("-------------------------------".cyan);
        }
    }

    // now check signature ....
    const chunk = binaryStream._buffer;

    const signatureIsOK = crypto_utils.verifyChunkSignatureWithDerivedKeys(chunk, derivedKeys);
    if (!signatureIsOK) {
        this._report_error("SIGN and ENCRYPT : Invalid packet signature");
        return false;
    }

    // remove signature
    binaryStream._buffer = crypto_utils.reduceLength(binaryStream._buffer, derivedKeys.signatureLength);

    if (this.securityMode === MessageSecurityMode.SIGNANDENCRYPT) {
        // remove padding
        binaryStream._buffer = crypto_utils.removePadding(binaryStream._buffer);
    }

    return true;
};