Language: JavaScript
Label: safe
CWE: CWE-331 \u2014 Insufficient Entropy
The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.

Code:
    CryptoModule.prototype.getHeaderData = function (encrypted) {
        if (!encrypted.metadata)
            return;
        var header = CryptorHeader.from(this.defaultCryptor.identifier, encrypted.metadata);
        var headerData = new Uint8Array(header.length);
        var pos = 0;
        headerData.set(header.data, pos);
        pos += header.length - encrypted.metadata.byteLength;
        headerData.set(new Uint8Array(encrypted.metadata), pos);
        return headerData.buffer;
    };