How to make an integrated address based on a subaddress?

Question

Monero is getting subaddresses soon. How are integrated addresses built upon those?

I'm trying the standard algorithm, using netbyte 0x35 (I'm on testnet) but the wallet rejects them as invalid.

Example:

• subaddress: BdZHh8j3gieLUtCWEQqQWRbakvLCvffrfMkUALrrAi2gHMrwfRzeeqHM2ZMCPzpqhg5ZsgHJQmAev3i7epY6yV7NJYQNfWf
• PID: c28347cea0f01641
• IA: 4Ghh5chLvwtLUtCWEQqQWRbakvLCvffrfMkUALrrAi2gHMrwfRzeeqHM2ZMCPzpqhg5ZsgHJQmAev3i7epY6yV7NT44nkedwuth8Mp7yns

However, with my algorithm and also with the address tester at https://xmr.llcoins.net/addresstests.html the base address computed back from the IA is: 47124osrKgNLUtCWEQqQWRbakvLCvffrfMkUALrrAi2gHMrwfRzeeqHM2ZMCPzpqhg5ZsgHJQmAev3i7epY6yV7NJZKb2gx

Before I dig into the source, can someone tell me if there are some rules I must follow when making IAs, or this is just not possible?

Answer 1

You don't. Subaddresses also solve the problem integrated addresses were designed for (allowing source identification in a single address). Since you can now generate a subaddress per source/client/customer, you don't need to assign a payment id anymore, so the ability to make integrated subaddresses was not added.