From 8bb94b81e14a4226eba2047b50903de5bf1e2f51 Mon Sep 17 00:00:00 2001 From: Jernej Kos Date: Mon, 11 Sep 2023 15:05:35 +0200 Subject: [PATCH] runtime-sdk/modules/evm: Do not zeroize query caller in new contracts --- runtime-sdk/modules/evm/src/backend.rs | 9 ++++ runtime-sdk/modules/evm/src/lib.rs | 14 +++++- runtime-sdk/modules/evm/src/state.rs | 25 ++++++++++- runtime-sdk/modules/evm/src/types.rs | 61 ++++++++++++++++++++++++++ 4 files changed, 106 insertions(+), 3 deletions(-) diff --git a/runtime-sdk/modules/evm/src/backend.rs b/runtime-sdk/modules/evm/src/backend.rs index 0ae4daac80..030d7b282b 100644 --- a/runtime-sdk/modules/evm/src/backend.rs +++ b/runtime-sdk/modules/evm/src/backend.rs @@ -550,6 +550,15 @@ impl<'ctx, 'backend, 'config, C: TxContext, Cfg: Config> StackState<'config> let mut store = state::codes(store); store.insert(address, code); }); + + // Set metadata for newly created contracts. + state::set_metadata( + &address.into(), + types::ContractMetadata { + // For all new contracts we don't zeroize the caller in queries. + features: types::FeatureMask::QUERIES_NO_CALLER_ZEROIZE, + }, + ); } fn transfer(&mut self, transfer: Transfer) -> Result<(), ExitError> { diff --git a/runtime-sdk/modules/evm/src/lib.rs b/runtime-sdk/modules/evm/src/lib.rs index 836ffb22b5..017b17282e 100644 --- a/runtime-sdk/modules/evm/src/lib.rs +++ b/runtime-sdk/modules/evm/src/lib.rs @@ -39,7 +39,7 @@ use oasis_runtime_sdk::{ }, }; -use types::{H160, H256, U256}; +use types::{FeatureMask, H160, H256, U256}; pub mod mock; #[cfg(test)] @@ -596,6 +596,7 @@ impl Module { if !Cfg::CONFIDENTIAL { return Ok((call, callformat::Metadata::Empty)); } + if let Ok(types::SignedCallDataPack { data, leash, @@ -615,13 +616,22 @@ impl Module { )); } + // Determine the caller based on per-contract features. + let caller = if state::get_metadata(&call.address) + .has_features(FeatureMask::QUERIES_NO_CALLER_ZEROIZE) + { + call.caller + } else { + Default::default() // Zeroize caller. + }; + // The call is not signed, but it must be encoded as an oasis-sdk call. let tx_call_format = transaction::CallFormat::Plain; // Queries cannot be encrypted. let (data, tx_metadata) = Self::decode_call_data(ctx, call.data, tx_call_format, 0, true)? .expect("processing always proceeds"); Ok(( types::SimulateCallQuery { - caller: Default::default(), // The sender cannot be spoofed. + caller, data, ..call }, diff --git a/runtime-sdk/modules/evm/src/state.rs b/runtime-sdk/modules/evm/src/state.rs index 41f3a3e0ba..4950aca2d4 100644 --- a/runtime-sdk/modules/evm/src/state.rs +++ b/runtime-sdk/modules/evm/src/state.rs @@ -3,7 +3,10 @@ use oasis_runtime_sdk::{ storage::{ConfidentialStore, CurrentStore, HashedStore, PrefixStore, Store, TypedStore}, }; -use crate::{types::H160, Config}; +use crate::{ + types::{ContractMetadata, H160}, + Config, +}; /// Prefix for Ethereum account code in our storage (maps H160 -> Vec). pub const CODES: &[u8] = &[0x01]; @@ -14,6 +17,8 @@ pub const STORAGES: &[u8] = &[0x02]; pub const BLOCK_HASHES: &[u8] = &[0x03]; /// Prefix for Ethereum account storage in our confidential storage (maps H160||H256 -> H256). pub const CONFIDENTIAL_STORAGES: &[u8] = &[0x04]; +/// Prefix for contract metadata (maps H160 -> ContractMetadata). +pub const METADATA: &[u8] = &[0x05]; /// Confidential store key pair ID domain separation context base. pub const CONFIDENTIAL_STORE_KEY_PAIR_ID_CONTEXT_BASE: &[u8] = b"oasis-runtime-sdk/evm: state"; @@ -118,3 +123,21 @@ pub fn block_hashes<'a, S: Store + 'a>(state: S) -> TypedStore let store = PrefixStore::new(state, &crate::MODULE_NAME); TypedStore::new(PrefixStore::new(store, &BLOCK_HASHES)) } + +/// Set contract metadata. +pub fn set_metadata(address: &H160, metadata: ContractMetadata) { + CurrentStore::with(|store| { + let store = PrefixStore::new(store, &crate::MODULE_NAME); + let mut store = TypedStore::new(PrefixStore::new(store, &METADATA)); + store.insert(address, metadata); + }) +} + +/// Get contract metadata. +pub fn get_metadata(address: &H160) -> ContractMetadata { + CurrentStore::with(|store| { + let store = PrefixStore::new(store, &crate::MODULE_NAME); + let store = TypedStore::new(PrefixStore::new(store, &METADATA)); + store.get(address).unwrap_or_default() + }) +} diff --git a/runtime-sdk/modules/evm/src/types.rs b/runtime-sdk/modules/evm/src/types.rs index 6898f66bab..0b80fa82cd 100644 --- a/runtime-sdk/modules/evm/src/types.rs +++ b/runtime-sdk/modules/evm/src/types.rs @@ -102,6 +102,46 @@ pub struct Leash { pub block_range: u64, } +/// Features affecting a contract's behavior. +#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, cbor::Encode, cbor::Decode)] +#[cbor(transparent)] +pub struct FeatureMask(pub u32); + +impl FeatureMask { + /// Caller should never be zeroized in queries. + pub const QUERIES_NO_CALLER_ZEROIZE: FeatureMask = FeatureMask(1 << 0); +} + +impl std::ops::BitOr for FeatureMask { + type Output = Self; + + fn bitor(self, rhs: Self) -> Self::Output { + Self(self.0 | rhs.0) + } +} + +impl std::ops::BitAnd for FeatureMask { + type Output = Self; + + fn bitand(self, rhs: Self) -> Self::Output { + Self(self.0 & rhs.0) + } +} + +/// Contract metadata. +#[derive(Clone, Debug, Default, cbor::Encode, cbor::Decode)] +pub struct ContractMetadata { + /// Features supported by the contract. + pub features: FeatureMask, +} + +impl ContractMetadata { + /// Check whether the contract has the specified features. + pub fn has_features(&self, mask: FeatureMask) -> bool { + self.features & mask == mask + } +} + // The rest of the file contains wrappers for primitive_types::{H160, H256, U256}, // so that we can implement cbor::{Encode, Decode} for them, ugh. // Remove this once oasis-cbor#8 is implemented. @@ -219,3 +259,24 @@ mod eth { impl_upstream_conversions!(H160, H256, U256); } pub use eth::{H160, H256, U256}; + +#[cfg(test)] +mod test { + use super::*; + + #[test] + fn test_contract_metadata() { + let meta = ContractMetadata::default(); + assert!(!meta.has_features(FeatureMask::QUERIES_NO_CALLER_ZEROIZE)); + + let meta = ContractMetadata { + features: FeatureMask::QUERIES_NO_CALLER_ZEROIZE, + }; + assert!(meta.has_features(FeatureMask::QUERIES_NO_CALLER_ZEROIZE)); + + let meta = ContractMetadata { + features: FeatureMask(0xff), + }; + assert!(meta.has_features(FeatureMask::QUERIES_NO_CALLER_ZEROIZE)); + } +}