ethers.utils.joinSignature(expandedSig) can not return correct signed transaction

[quicklearnpro]

Describe your Issue

Hi there,

Below is an actual signed transaction which has been sent to Ropsten network: https://ropsten.etherscan.io/tx/0xf4727b35f10cbe2256b38adcc594f25854a7f16c8461e280079e7003a18d446d

signed_transaction =
0xf86b808504a817c800825208942890228d4478e2c3b0ebf5a38479e3396c1d6074872386f26fc100008029a0520e5053c1b573d747f823a0b23d52e5a619298f46cd781d677d0e5e78fbc750a075be461137c2c2a5594beff76ecb11a215384c574a7e5b620dba5cc63b0a0f13

I try to use the following code to get the corresponding signed_transaction from the tx hash id.
const tx = await infuraProvider.getTransaction( "0xf4727b35f10cbe2256b38adcc594f25854a7f16c8461e280079e7003a18d446d ")
const expandedSig = {
r: tx.r,
s: tx.s,
v: tx.v
}
const signature = ethers.utils.joinSignature(expandedSig)

unfortunately, the result of "signature" can't match signed_transaction.
I googled everywhere, this is the solution I found.
I have to figure it out asap to meet my boss's deadline.

Could you please let me know if there is any solution?
Any sugguestion will be highly appreciated!

Regards,

Brad

This is an exception issue

• I understand this form is for exceptional issues and believe my issue qualifies.

[ricmoo]

(This is not a valid use of the exceptional issue template. Please use discussions in the future.)

I don't know what you mean by "the result of "signature" can't match signed_transaction".

The joinSignautre method uses a canonical v (either 27 or 28), while a transaction's v post-EIP-155 is computed from the chain ID.

A signed transaction doesn't have a concept of an opaque transaction; it is either signed (in which case its r, s and v are set) or unsigned (in which case none are). There is no flat "signature" for a transaction.

[quicklearnpro]

Hi ricmoo,

I am so exciting to get the response from you so prompt and from you directly!!!!
I am your fan, and you are legend in my heart!
Sorry for misleading you.
The requirement is very simple, my boss ask me to provide a method to get the tx's signed transaction by input the tx_hash_id:
funciton get_signed_transaction_from_tx( tx_id ){
...............
}
for example: input is: [0xf4727b35f10cbe2256b38adcc594f25854a7f16c8461e280079e7003a18d446d] (https://ropsten.etherscan.io/tx/0xf4727b35f10cbe2256b38adcc594f25854a7f16c8461e280079e7003a18d446d)
and output is the signed_transaction hex:
0xf86b808504a817c800825208942890228d4478e2c3b0ebf5a38479e3396c1d6074872386f26fc100008029a0520e5053c1b573d747f823a0b23d52e5a619298f46cd781d677d0e5e78fbc750a075be461137c2c2a5594beff76ecb11a215384c574a7e5b620dba5cc63b0a0f13
After googled from internet, I know how to generate signed_transaction hex by using a wallet:
let rawTransaction = await wallet.signTransaction(transaction).then(ethers.utils.serializeTransaction(transaction));

But I am stuck to get the signed_transaction hex (signed (in which case its r, s and v are set) ) back by using tx_hash_id.
I can get the V R S, by using
const tx = await infuraProvider.getTransaction( "0xf4727b35f10cbe2256b38adcc594f25854a7f16c8461e280079e7003a18d446d ")
const expandedSig = {
r: tx.r,
s: tx.s,
v: tx.v
}

I used:
const rsTx = await ethers.utils.resolveProperties(txData)

const raw = ethers.utils.serializeTransaction(rsTx)

const msgHash = ethers.utils.keccak256(raw)
but none of them are signed_transaction hex (signed (in which case its r, s and v are set) )

Is it possible for me to get the original signed_transaction hex back?

Thanks a lot, ricmoo! Your ethers.js is a really great product!!!

Regards,

Brad

[ricmoo]

You are looking for serializeTransaction. you will need to remove conflicting keys from a transaction response (in v6 you won’t): see the example in the cookbook here.

It’s similar to what you have, but if you want a signed transaction, you must pass in your signature as the second parameter to serializeTransaction otherwise it just returns the transaction pre-image to sign.

Hope that helps! :)