Support LondonSigner in Ledger USBWallet

[shrimalmadhur]

Rationale

Why should this feature exist?
Currently Ledger only support LegacyTx and I want it to support DynamicTx as the LegacyTx is well, Legacy.

go-ethereum/accounts/usbwallet/ledger.go

Lines 379 to 387 in f59d013

	// Create the correct signer and signature transform based on the chain ID
	var signer types.Signer
	if chainID == nil {
	signer = new(types.HomesteadSigner)
	} else {
	signer = types.NewEIP155Signer(chainID)
	signature[64] -= byte(chainID.Uint64()*2 + 35)
	}
	signed, err := tx.WithSignature(signer, signature)

What are the use-cases?
Can use EIP1559 dynamic fee tx

Implementation

Do you have ideas regarding the implementation of this feature?
No - I have been reading the code and trying to see what all changes I will have to make, but I can give it a shot.

From what I understand this block needs to support typed transactions as ethereum app on ledger supports parsing that.

go-ethereum/accounts/usbwallet/ledger.go

Lines 336 to 343 in f59d013

	if chainID == nil {
	if txrlp, err = rlp.EncodeToBytes([]interface{}{tx.Nonce(), tx.GasPrice(), tx.Gas(), tx.To(), tx.Value(), tx.Data()}); err != nil {
	return common.Address{}, nil, err
	}
	} else {
	if txrlp, err = rlp.EncodeToBytes([]interface{}{tx.Nonce(), tx.GasPrice(), tx.Gas(), tx.To(), tx.Value(), tx.Data(), chainID, big.NewInt(0), big.NewInt(0)}); err != nil {
	return common.Address{}, nil, err
	}

I still don't know how to deal with this though

go-ethereum/accounts/usbwallet/ledger.go

Lines 353 to 357 in f59d013

	// Chunk size selection to mitigate an underlying RLP deserialization issue on the ledger app.
	// https://github.com/LedgerHQ/app-ethereum/issues/409
	chunk := 255
	for ; len(payload)%chunk <= ledgerEip155Size; chunk-- {
	}

Are you willing to implement this feature?
Yes