EVMHost: Add size%192 check to bn128pairing

And also refactor resultWithFailure

Author: axic

test/EVMHost.cpp

@@ -495,9 +495,7 @@ evmc::result EVMHost::precompileIdentity(evmc_message const& _message) noexcept
 evmc::result EVMHost::precompileModExp(evmc_message const&) noexcept
 {
 	// TODO implement
-	evmc::result result({});
-	result.status_code = EVMC_FAILURE;
-	return result;
+	return resultWithFailure();
 }
 
 evmc::result EVMHost::precompileALTBN128G1Add(evmc_message const& _message) noexcept
@@ -773,6 +771,11 @@ evmc::result EVMHost::precompileALTBN128G1Mul(evmc_message const& _message) noex
 
 evmc::result EVMHost::precompileALTBN128PairingProduct(evmc_message const& _message) noexcept
 {
+	// Input must be divisible by 192.
+	// TODO: validate points
+	if (_message.input_size % 192)
+		return resultWithFailure();
+
 	// This is a partial implementation - it always returns "success"
 	bytes static data = fromHex("0000000000000000000000000000000000000000000000000000000000000001");
 	return resultWithGas(_message, data);
@@ -786,11 +789,14 @@ evmc::result EVMHost::precompileGeneric(
 	if (_inOut.count(input))
 		return resultWithGas(_message, _inOut.at(input));
 	else
-	{
-		evmc::result result({});
-		result.status_code = EVMC_FAILURE;
-		return result;
-	}
+		return resultWithFailure();
+}
+
+evmc::result EVMHost::resultWithFailure() noexcept
+{
+	evmc::result result({});
+	result.status_code = EVMC_FAILURE;
+	return result;
 }
 
 evmc::result EVMHost::resultWithGas(

test/EVMHost.h

@@ -116,6 +116,7 @@ class EVMHost: public evmc::MockedHost
 	/// @returns a result object with no gas usage and result data taken from @a _data.
 	/// @note The return value is only valid as long as @a _data is alive!
 	static evmc::result resultWithGas(evmc_message const& _message, bytes const& _data) noexcept;
+	static evmc::result resultWithFailure() noexcept;
 
 	evmc::VM& m_vm;
 	/// EVM version requested by the testing tool