I want customize a transaction to include some data. Monero has tx_extra (src/cryptonote_basic/tx_extra.h) and I know how to use monerod RPC /send_raw_transaction.
I want to send nonce data whose length is 256bit, but I don't know how to change data to hex. Please teach me how can I change data to hex (i.e. send raw data).
Here is the example scenario.
sender Alice(0xaa), receiver Bob(0xbb)
Alice wants to send a transaction to Bob using monero which includeds sha256(hello bob).
(I want to use Monero to guarantee 'hello bob' but they don't know who sends and receives except Alice and Bob, so I use Monero.)