security/src/main/java/io/airlift/security/der/DerUtils.java
public static byte[] encodeOctetString(byte[] value)
    {
        byte[] lengthEncoded = encodeLength(value.length);
        ByteArrayDataOutput out = ByteStreams.newDataOutput(2 + lengthEncoded.length + value.length);
        out.write(OCTET_STRING_TAG);
        out.write(lengthEncoded);
        out.write(value);
        return out.toByteArray();
    }
public static byte[] encodeOctetString(byte[] value)
    {
        byte[] lengthEncoded = encodeLength(value.length);
        ByteArrayDataOutput out = ByteStreams.newDataOutput(2 + lengthEncoded.length + value.length);
        out.write(OCTET_STRING_TAG);
        out.write(lengthEncoded);
        out.write(value);
        return out.toByteArray();
    }
Encodes an octet string.