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 (data) {
            var encryptedData = new Uint8Array(data);
            var sentinel = '';
            var version = null;
            if (encryptedData.byteLength >= 4) {
                sentinel = encryptedData.slice(0, 4);
                if (this.decoder.decode(sentinel) !== CryptorHeader.SENTINEL)
                    return '';
            }
            if (encryptedData.byteLength >= 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.byteLength >= pos) {
                identifier = encryptedData.slice(5, pos);
            }
            else {
                throw new Error('decryption error. invalid crypto identifier');
            }
            var metadataLength = null;
            if (encryptedData.byteLength >= pos + 1) {
                metadataLength = encryptedData[pos];
            }
            else {
                throw new Error('decryption error. invalid metadata length');
            }
            pos += 1;
            if (metadataLength === 255 && encryptedData.byteLength >= pos + 2) {
                metadataLength = new Uint16Array(encryptedData.slice(pos, pos + 2)).reduce(function (acc, val) { return (acc << 8) + val; }, 0);
                pos += 2;
            }
            return new CryptorHeaderV1(this.decoder.decode(identifier), metadataLength);
        };