runtime-sdk/modules/evm: Do not zeroize query caller in new contracts

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> {

runtime-sdk/modules/evm/src/lib.rs

@@ -39,8 +39,9 @@ use oasis_runtime_sdk::{
     },
 };
 
-use types::{H160, H256, U256};
+use types::{FeatureMask, H160, H256, U256};
 
+#[cfg(any(test, feature = "test"))]
 pub mod mock;
 #[cfg(test)]
 mod test;
@@ -596,6 +597,7 @@ impl<Cfg: Config> Module<Cfg> {
         if !Cfg::CONFIDENTIAL {
             return Ok((call, callformat::Metadata::Empty));
         }
+
         if let Ok(types::SignedCallDataPack {
             data,
             leash,
@@ -615,13 +617,22 @@ impl<Cfg: Config> Module<Cfg> {
             ));
         }
 
+        // 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
             },

runtime-sdk/modules/evm/src/mock.rs

@@ -2,13 +2,20 @@
 use uint::hex::FromHex;
 
 use oasis_runtime_sdk::{
+    callformat,
+    core::common::crypto::mrae::deoxysii,
     dispatcher,
+    error::RuntimeError,
+    module,
     testing::mock::{CallOptions, Signer},
-    types::address::SignatureAddressSpec,
+    types::{address::SignatureAddressSpec, transaction},
     BatchContext,
 };
 
-use crate::types::{self, H160};
+use crate::{
+    derive_caller,
+    types::{self, H160},
+};
 
 /// A mock EVM signer for use during tests.
 pub struct EvmSigner(Signer);
@@ -64,6 +71,104 @@ impl EvmSigner {
             opts,
         )
     }
+
+    /// Ethereum address for this signer.
+    pub fn address(&self) -> H160 {
+        derive_caller::from_sigspec(self.sigspec()).expect("caller should be evm-compatible")
+    }
+
+    /// Dispatch a query to the given EVM contract method.
+    pub fn query_evm<C>(
+        &self,
+        ctx: &mut C,
+        address: H160,
+        name: &str,
+        param_types: &[ethabi::ParamType],
+        params: &[ethabi::Token],
+    ) -> Result<Vec<u8>, RuntimeError>
+    where
+        C: BatchContext,
+    {
+        self.query_evm_opts(ctx, address, name, param_types, params, Default::default())
+    }
+
+    /// Dispatch a query to the given EVM contract method.
+    pub fn query_evm_opts<C>(
+        &self,
+        ctx: &mut C,
+        address: H160,
+        name: &str,
+        param_types: &[ethabi::ParamType],
+        params: &[ethabi::Token],
+        opts: QueryOptions,
+    ) -> Result<Vec<u8>, RuntimeError>
+    where
+        C: BatchContext,
+    {
+        let mut data = [
+            ethabi::short_signature(name, param_types).to_vec(),
+            ethabi::encode(params),
+        ]
+        .concat();
+
+        // Handle optional encryption.
+        let client_keypair = deoxysii::generate_key_pair();
+        if opts.encrypt {
+            data = cbor::to_vec(
+                callformat::encode_call(
+                    ctx,
+                    transaction::Call {
+                        format: transaction::CallFormat::EncryptedX25519DeoxysII,
+                        method: "".into(),
+                        body: cbor::Value::from(data),
+                        ..Default::default()
+                    },
+                    &client_keypair,
+                )
+                .unwrap(),
+            );
+        }
+
+        let mut result: Vec<u8> = self.query(
+            ctx,
+            "evm.SimulateCall",
+            types::SimulateCallQuery {
+                gas_price: 0.into(),
+                gas_limit: opts.gas_limit,
+                caller: opts.caller.unwrap_or_else(|| self.address()),
+                address,
+                value: 0.into(),
+                data,
+            },
+        )?;
+
+        // Handle optional decryption.
+        if opts.encrypt {
+            let call_result: transaction::CallResult =
+                cbor::from_slice(&result).expect("result from EVM should be properly encoded");
+            let call_result = callformat::decode_result(
+                ctx,
+                transaction::CallFormat::EncryptedX25519DeoxysII,
+                call_result,
+                &client_keypair,
+            )
+            .expect("callformat decoding should succeed");
+
+            result = match call_result {
+                module::CallResult::Ok(v) => {
+                    cbor::from_value(v).expect("result from EVM should be correct")
+                }
+                module::CallResult::Failed {
+                    module,
+                    code,
+                    message,
+                } => return Err(RuntimeError::new(&module, code, &message)),
+                module::CallResult::Aborted(e) => panic!("aborted with error: {e}"),
+            };
+        }
+
+        Ok(result)
+    }
 }
 
 impl std::ops::Deref for EvmSigner {
@@ -80,6 +185,26 @@ impl std::ops::DerefMut for EvmSigner {
     }
 }
 
+/// Options for making queries.
+pub struct QueryOptions {
+    /// Whether the call should be encrypted.
+    pub encrypt: bool,
+    /// Gas limit.
+    pub gas_limit: u64,
+    /// Use specified caller instead of signer.
+    pub caller: Option<H160>,
+}
+
+impl Default for QueryOptions {
+    fn default() -> Self {
+        Self {
+            encrypt: false,
+            gas_limit: 10_000_000,
+            caller: None,
+        }
+    }
+}
+
 /// Load contract bytecode from a hex-encoded string.
 pub fn load_contract_bytecode(raw: &str) -> Vec<u8> {
     Vec::from_hex(raw.split_whitespace().collect::<String>())

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<u8>).
 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<impl Store + 'a>
     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()
+    })
+}

runtime-sdk/modules/evm/src/test.rs

@@ -27,7 +27,8 @@ use oasis_runtime_sdk::{
 
 use crate::{
     derive_caller,
-    mock::{decode_reverted, decode_reverted_raw, load_contract_bytecode, EvmSigner},
+    mock::{decode_reverted, decode_reverted_raw, load_contract_bytecode, EvmSigner, QueryOptions},
+    state,
     types::{self, H160},
     Config, Genesis, Module as EVMModule,
 };
@@ -792,6 +793,91 @@ fn test_c10l_evm_runtime() {
     do_test_evm_runtime::<ConfidentialEVMConfig>();
 }
 
+#[test]
+fn test_c10l_queries() {
+    let mut mock = mock::Mock::default();
+    let mut ctx = mock.create_ctx_for_runtime::<EVMRuntime<ConfidentialEVMConfig>>(
+        context::Mode::ExecuteTx,
+        true,
+    );
+    let mut signer = EvmSigner::new(0, keys::dave::sigspec());
+
+    EVMRuntime::<ConfidentialEVMConfig>::migrate(&mut ctx);
+
+    static QUERY_CONTRACT_CODE_HEX: &str =
+        include_str!("../../../../tests/e2e/contracts/query/query.hex");
+
+    // Create contract.
+    let dispatch_result = signer.call(
+        &mut ctx,
+        "evm.Create",
+        types::Create {
+            value: 0.into(),
+            init_code: load_contract_bytecode(QUERY_CONTRACT_CODE_HEX),
+        },
+    );
+    let result = dispatch_result.result.unwrap();
+    let result: Vec<u8> = cbor::from_value(result).unwrap();
+    let contract_address = H160::from_slice(&result);
+
+    let mut ctx = mock
+        .create_ctx_for_runtime::<EVMRuntime<ConfidentialEVMConfig>>(context::Mode::CheckTx, true);
+
+    // Call the `test` method on the contract via a query.
+    let result = signer
+        .query_evm(&mut ctx, contract_address, "test", &[], &[])
+        .expect("query should succeed");
+
+    let mut result =
+        ethabi::decode(&[ParamType::Address], &result).expect("output should be correct");
+
+    let test = result.pop().unwrap().into_address().unwrap();
+    assert_eq!(
+        test,
+        signer.address().into(),
+        "msg.signer should be correct (non-zeroized)"
+    );
+
+    // Test call with confidential envelope.
+    let result = signer
+        .query_evm_opts(
+            &mut ctx,
+            contract_address,
+            "test",
+            &[],
+            &[],
+            QueryOptions {
+                encrypt: true,
+                ..Default::default()
+            },
+        )
+        .expect("query should succeed");
+
+    let mut result =
+        ethabi::decode(&[ParamType::Address], &result).expect("output should be correct");
+
+    let test = result.pop().unwrap().into_address().unwrap();
+    assert_eq!(
+        test,
+        signer.address().into(),
+        "msg.signer should be correct (non-zeroized)"
+    );
+
+    // Reset the contract metadata to remove the QUERIES_NO_CALLER_ZEROIZE feature.
+    state::set_metadata(&contract_address, Default::default());
+
+    // Call the `test` method again on the contract via a query.
+    let result = signer
+        .query_evm(&mut ctx, contract_address, "test", &[], &[])
+        .expect("query should succeed");
+
+    let mut result =
+        ethabi::decode(&[ParamType::Address], &result).expect("output should be correct");
+
+    let test = result.pop().unwrap().into_address().unwrap();
+    assert_eq!(test, Default::default(), "msg.signer should be zeroized");
+}
+
 #[test]
 fn test_fee_refunds() {
     let mut mock = mock::Mock::default();