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:
    CryptorHeader.tryParse = function (encryptedData) {
        var sentinel = '';
        var version = null;
        if (encryptedData.length >= 4) {
            sentinel = encryptedData.slice(0, 4);
            if (sentinel.toString('utf8') !== CryptorHeader.SENTINEL)
                return '';
        }
        if (encryptedData.length >= 5) {
            version = encryptedData[4];
        }
        else {
            throw new Error('decryption error. invalid header version');
        }
        if (version > CryptorHeader.MAX_VERSION)
            throw new Error('unknown cryptor error');
        var identifier;
        var pos = 5 + CryptorHeader.IDENTIFIER_LENGTH;
        if (encryptedData.length >= pos) {
            identifier = encryptedData.slice(5, pos);
        }
        else {
            throw new Error('decryption error. invalid crypto identifier');
        }
        var metadataLength = null;
        if (encryptedData.length >= pos + 1) {
            metadataLength = encryptedData[pos];
        }
        else {
            throw new Error('decryption error. invalid metadata length');
        }
        pos += 1;
        if (metadataLength === 255 && encryptedData.length >= pos + 2) {
            metadataLength = new Uint16Array(encryptedData.slice(pos, pos + 2)).reduce(function (acc, val) { return (acc << 8) + val; }, 0);
            pos += 2;
        }
        return new CryptorHeaderV1(identifier.toString('utf8'), metadataLength);
    };