pls what hex was hashed and signed in the example

Question

Thank you for your answer.
I get it now, txid "998d1c901447c87698ff7a1c5cab64ad7372d49c71c88446f83e21d54ae7d637" is a source tranasction.

Pls let me update my former question.
The "raw transaction hex" created in step 3 gives "txid" : "9fca64d032736495ba6aaaec1eb117921ddfbaf999a6317b226b2fecdd621bfa",

Please is "9fca64d032736495ba6aaaec1eb117921ddfbaf999a6317b226b2fecdd621bfa" exactly the hash that was signed, or was it a different one?

In the second case pls could you disclose the "example hex" that was hashed in order to be afterward signed, or describe how it was created.

Thank you in advance.

Answer 1

The txid of a transaction is just a hash of its contents. So the txid of the transaction will change from when it is first created, to when it is fully signed and ready for broadcast.

In any event, it's not the txid that is signed, but rather the content of the transaction's inputs and/or outputs (depending on the type of signature).

As for the exact way in which the signature is calculated given those inputs and outputs, please refer to any documentation for the bitcoin protocol, for example: https://bitcoin.stackexchange.com/questions/32305/how-does-the-ecdsa-verification-algorithm-work-during-transaction