EIP-3607: transactions from senders with deployed contract are forbidden

[MariusVanDerWijden]

Draft PR for EIP-3607 (https://eips.ethereum.org/EIPS/eip-3607).
Waits for 3607 to be approved by the Core Devs

cc @dankrad

[holiman]

LGTM (text-wise, haven't reviewed the rendered diff)

[yperbasis]

The condition should be

\boldsymbol{\sigma}[S(T)]_{\mathrm{c}} = \texttt{KEC}\big( () \big)

i.e. that sender's codeHash is that of an empty string.
For example, check the definition of an empty account in Eq (14).

I_{\mathbf{b}} isn't correct: it refers to initialising code, not sender's code.

Also, please add the condition to the validity Eq (59).

[MariusVanDerWijden]

@yperbasis we discussed the change on ACD and decided to go with empty codehash as the condition instead of codesize as you proposed. Will un-draft the PR once the changes are merged into the EIP, the tests and the EIP is moved into Final

[holiman]

See ethereum/go-ethereum#23002 (comment)

Basically, a client implementing this change must be careful. If the same 'check' as EXTCODEHASH is reused for this check, then it needs to allow both 0x000.. and emptyCodeHash. Because a transaction from an account that did not previously exist is historically OK, if a miner accepts a gasPrice of zero. Which has happened.

[yperbasis]

Shall we merge it, given that it's already in geth (ethereum/go-ethereum#23303) ?