Transfer Hook - How to get destination ATA owner public key

Question

For my program, I need to implement the Token2022 transfer hook. Inside the transfer hook, I need to read and write a PDA account driven from the address of the owner of the destination ATA.

EDIT: In the transfer hook I need to update 2 PDAs (user state). One is for the sender, and one is for the receiver. Everything is fine with the sender since we have it as a parameter in the transfer instruction. But we don't have the receiver's wallet address.

Here is how I initialize the PDA account

    pub user: AccountInfo<'info>,
    #[account(
        init,
        payer = _payer,
        space =  UserCampaignState::space(),
        seeds = [
            USER_CAMPAIGN_STATE_SEED.as_ref(),
            user.key().as_ref(),
        ],
        bump
    )]
    pub user_state: Account<'info, UserCampaignState>,

According to documentation, in ExtraAccountMetaList we have the owner of the source ATA (index 3), but no receiver, unfortunately.

index 0-3 are the accounts required for token transfer (source, mint, destination, owner)

So, my question is how to initialize ExtraAccountMetaList with the receiver's address and/or PDA. OR is there a workaround inside transfer_hook to get a PDA by the receiver's address and, most importantly, write in it?

Thank you in advance! I hope this will help others who struggle with receiver in transfer hook as well :)

Answer 1

The 3rd account (index 2) labeled destination_token is the recipient token account from the initial token transfer.

You should be able to access the address of the owner stored on the token account to derive the PDA.

Answer 2

        let destination_token_info = ctx.accounts.destination_token.to_account_info();
        let destination_token_data = destination_token_info.try_borrow_data()?;
        let destination_owner = Pubkey::try_from(&destination_token_data[32..64]).unwrap();

I think this code can help you.