pyth-crosschain/target_chains/ethereum/contracts/wormhole/Messages.sol

141 lines
4.0 KiB
Solidity

// contracts/Messages.sol
// SPDX-License-Identifier: Apache 2
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;
import "./Getters.sol";
import "./Structs.sol";
import "../libraries/external/BytesLib.sol";
contract Messages is Getters {
using BytesLib for bytes;
function parseAndVerifyVM(
bytes calldata encodedVM
)
public
view
returns (Structs.VM memory vm, bool valid, string memory reason)
{
vm = parseVM(encodedVM);
(valid, reason) = verifyVM(vm);
}
function verifyVM(
Structs.VM memory vm
) public view returns (bool valid, string memory reason) {
Structs.GuardianSet memory guardianSet = getGuardianSet(
vm.guardianSetIndex
);
if (guardianSet.keys.length == 0) {
return (false, "invalid guardian set");
}
if (
vm.guardianSetIndex != getCurrentGuardianSetIndex() &&
guardianSet.expirationTime < block.timestamp
) {
return (false, "guardian set has expired");
}
// We're using a fixed point number transformation with 1 decimal to deal with rounding.
if (
(((guardianSet.keys.length * 10) / 3) * 2) / 10 + 1 >
vm.signatures.length
) {
return (false, "no quorum");
}
// Verify signatures
(bool signaturesValid, string memory invalidReason) = verifySignatures(
vm.hash,
vm.signatures,
guardianSet
);
if (!signaturesValid) {
return (false, invalidReason);
}
return (true, "");
}
function verifySignatures(
bytes32 hash,
Structs.Signature[] memory signatures,
Structs.GuardianSet memory guardianSet
) public pure returns (bool valid, string memory reason) {
uint8 lastIndex = 0;
for (uint i = 0; i < signatures.length; i++) {
Structs.Signature memory sig = signatures[i];
require(
i == 0 || sig.guardianIndex > lastIndex,
"signature indices must be ascending"
);
lastIndex = sig.guardianIndex;
if (
ecrecover(hash, sig.v, sig.r, sig.s) !=
guardianSet.keys[sig.guardianIndex]
) {
return (false, "VM signature invalid");
}
}
return (true, "");
}
function parseVM(
bytes memory encodedVM
) public pure virtual returns (Structs.VM memory vm) {
uint index = 0;
vm.version = encodedVM.toUint8(index);
index += 1;
require(vm.version == 1, "VM version incompatible");
vm.guardianSetIndex = encodedVM.toUint32(index);
index += 4;
// Parse Signatures
uint256 signersLen = encodedVM.toUint8(index);
index += 1;
vm.signatures = new Structs.Signature[](signersLen);
for (uint i = 0; i < signersLen; i++) {
vm.signatures[i].guardianIndex = encodedVM.toUint8(index);
index += 1;
vm.signatures[i].r = encodedVM.toBytes32(index);
index += 32;
vm.signatures[i].s = encodedVM.toBytes32(index);
index += 32;
vm.signatures[i].v = encodedVM.toUint8(index) + 27;
index += 1;
}
// Hash the body
bytes memory body = encodedVM.slice(index, encodedVM.length - index);
vm.hash = keccak256(abi.encodePacked(keccak256(body)));
// Parse the body
vm.timestamp = encodedVM.toUint32(index);
index += 4;
vm.nonce = encodedVM.toUint32(index);
index += 4;
vm.emitterChainId = encodedVM.toUint16(index);
index += 2;
vm.emitterAddress = encodedVM.toBytes32(index);
index += 32;
vm.sequence = encodedVM.toUint64(index);
index += 8;
vm.consistencyLevel = encodedVM.toUint8(index);
index += 1;
vm.payload = encodedVM.slice(index, encodedVM.length - index);
}
}