EIP-7702 Implementation for pallet-revive

[Wizdave97]

Description

This PR implements EIP-7702: Set EOA Account Code for pallet-revive. This implementation allows Externally Owned Accounts (EOAs) to temporarily delegate their execution to smart contract code via signed authorizations.

Key Components Implemented

1. Core Authorization Processing (src/evm/eip7702.rs)

New Module: Complete implementation of authorization tuple processing

• process_authorizations(): Main function to process authorization lists
• process_single_authorization(): Validates individual authorization tuples
• recover_authority(): Recovers signer address using ECDSA signature recovery
• authorization_intrinsic_gas(): Calculates gas costs for authorizations

Key Features:

• Signature validation with EIP-2 compliance (normalized s-values)
• Chain ID validation (0 = any chain, or must match current chain)
• Nonce verification
• Authority recovery using keccak256(MAGIC || rlp([chain_id, address, nonce]))
• Last-valid-wins logic for multiple authorizations from same authority

2. Delegation Indicator Storage (src/storage.rs)

Extended AccountInfo with EIP-7702-specific methods:

// Check if code is a delegation indicator
pub fn is_delegation_indicator(code: &[u8]) -> bool

// Extract target address from delegation indicator
pub fn extract_delegation_target(code: &[u8]) -> Option<H160>

// Check if account has delegation set
pub fn is_delegated(address: &H160) -> bool

// Get delegation target
pub fn get_delegation_target(address: &H160) -> Option<H160>

// Set delegation indicator (0xef0100 || address)
pub fn set_delegation(address: &H160, target: H160, nonce: T::Nonce) -> Result<(), DispatchError>

// Clear delegation, restore to EOA
pub fn clear_delegation(address: &H160) -> Result<(), DispatchError>

Storage Strategy:

• Delegation indicators stored directly in PristineCode without CodeInfo
• No refcounting/ownership tracking needed
• Format: 0xef0100 || <20-byte address> (23 bytes total)

3. Code Execution Resolution (src/exec.rs)

New Function: resolve_delegation(code_hash: H256) -> H256

• Checks if code is a delegation indicator
• Resolves to target contract's code hash
• Only follows one level of delegation (prevents loops per EIP-7702)
• Returns EMPTY_CODE_HASH if target is not a contract
• Integrated into:
  • new_frame() for contract calls
  • Delegate calls

Behavior:

• CALL, CALLCODE, DELEGATECALL, STATICCALL follow delegation
• EXTCODEHASH, EXTCODESIZE, EXTCODECOPY operate on delegation indicator itself
• During delegated execution: CODESIZE ≠ EXTCODESIZE (per spec)

4. Transaction Integration (src/lib.rs, src/evm/call.rs)

Modified Dispatchables:

pub fn eth_call(
    // ... existing parameters ...
    authorization_list: Vec<evm::AuthorizationListEntry>,
) -> DispatchResultWithPostInfo

Note: authorization_list is only added to eth_call, not to eth_instantiate_with_code. EIP-7702 is for setting code on existing EOAs, not for contract creation.

Processing Flow:

1. Authorization list processed (new step)
2. Delegation indicators set/cleared
3. Increment account nonce
4. Contract execution proceeds

New Helper Function:

pub fn process_eip7702_authorizations(
    authorization_list: Vec<evm::AuthorizationListEntry>,
    accessed_addresses: &mut alloc::collections::BTreeSet<H160>,
) -> u64  // Returns gas refund

6. EIP-3607 Modification (src/lib.rs)

Updated ensure_non_contract_if_signed():

// Allow EOAs with delegation indicators to originate transactions
if AccountInfo::<T>::is_contract(&address) {
    if AccountInfo::<T>::is_delegated(&address) {
        return Ok(())  // ✅ Allow delegated EOAs
    }
    return Err(DispatchError::BadOrigin)  // ❌ Reject regular contracts
}

// ❌ Reject precompiles
if exec::is_precompile::<T, ContractBlob<T>>(&address) {
    return Err(DispatchError::BadOrigin)
}

Per EIP-7702: EOAs with valid delegation indicators can originate transactions.

[pgherveou]

/bot fmt

[pgherveou]

can you remove the pure fmt diff, it will make it easier to review

[Wizdave97]

can you remove the pure fmt diff, it will make it easier to review

Done

[pgherveou]

Hey, thanks for putting this together.
I think the implementation still has a few gaps; I’ve added some initial remarks.

[Wizdave97]

@pgherveou I've attended to the comments, please check it out when you can.
Also I wasn't able to run the benchmarks locally because pallet-revive-fixtures gets stuck while building.

[pgherveou]

pallet-revive-fixtures gets stuck while building

it requires some bin like solc & resolc I believe, the build error should tell you why it fails I presume

[Wizdave97]

pallet-revive-fixtures gets stuck while building

it requires some bin like solc & resolc I believe, the build error should tell you why it fails I presume

It doesn't fail, it just gets stuck on building and never progresses.

I'll try again, maybe I wasn't patient enough

[Wizdave97]

pallet-revive-fixtures gets stuck while building

it requires some bin like solc & resolc I believe, the build error should tell you why it fails I presume

It doesn't fail, it just gets stuck on building and never progresses.

I'll try again, maybe I wasn't patient enough

Gets stuck at this point for more than 20 minutes