Wormhole资产跨链项目代码解析

1. 引言

Wormhole支持基于Solana与多个链进行资产转移，开源代码为：

• https://github.com/certusone/wormhole/tree/main

实际部署配置信息参见：

• https://github.com/certusone/wormhole-networks

当前已上线V1，已支持：

未来V2将支持：

2. Wormhole V1

Connected chain contracts：

NetworkBridge contract addresssEthereum Mainnet (Bridge)0xf92cD566Ea4864356C5491c177A430C222d7e678 (verified on Etherscan)Ethereum Mainnet (Token)0x9A5e27995309a03f8B583feBdE7eF289FcCdC6Ae (verified on Etherscan)Solana Mainnet BetaWormT3McKhFJ2RkiGpdw9GKvNCrB2aB54gb2uV9MfQC

Guardian set with 19 decentralized guardians：

NetworkGuardian Set initializationSolana3mQpDW2ofC3YpAsDzP4w5FNVzYRSmJjKoio4fcapL7xDAdaatvvKXCzrd2cfHiVNwYZs4hH1ePZ9Hep4zaasL27LEthereum0x833e7bec034d9904713d6a7dc13d197ec41af2d0611122603289a1e69ae72c43

19个Guardians采用PoA共识，不存在leader。Wormhole V1版本中的调用Solana合约的submitVAA()函数的手续费由Guardian承担。由于没有leader，会存在有多个同时提交的情况：

• https://explorer.solana.com/tx/67dyCCe2cb3UEab8J64p8gMTxc5WaiQww64JUXQddyjt53HfCzumgt1JhsKjG2qTo2phHS5e6rSTzWD8gupa8PgP 成功。
• https://explorer.solana.com/tx/TZKNGEK5bkd3kY92NKXDxAtA8ZTmiR4C3MvyyBgMT6P3drn5XhcUUdUPaL7WViZkN6wqRWCBRKvNzMuvwgredty 失败，Solana合约中报错：AlreadyExists。
• https://explorer.solana.com/tx/2nbGGDxyqRKb9edcraZK3EoPHVq8CGm5BQEy6iiVzipzDqoWD3Smx9bTvapWjDYUhVt8boQBn6GvdGQRdrdrBDJV 失败，Solana合约中报错：AlreadyExists。
• https://explorer.solana.com/tx/4d2KwDKRtifdq6NCNztF3wk6iZBD77fq7aRf7TSnAgeVPL9fRUj3PtkhNL2GJ9M5TQXeku6ffMLfdAF7C5dyzwgj 失败，Solana合约中报错：AlreadyExists。
• https://explorer.solana.com/tx/4q55JYoo5Cb8XaXpxsZVyBdXs1imHhv44ygdti6Lf49ZddFzy3gCknRNiAHr5ZQmhXd9wdBkUeZKubAZWHMQTNet 合约中报错：AlreadyExists。

Solana端合约日志为：

Program WormT3McKhFJ2RkiGpdw9GKvNCrB2aB54gb2uV9MfQC invoke [1]
Instruction: VerifySignatures
Error: AlreadyExists
Program WormT3McKhFJ2RkiGpdw9GKvNCrB2aB54gb2uV9MfQC consumed 50274 of 200000 compute units
Program WormT3McKhFJ2RkiGpdw9GKvNCrB2aB54gb2uV9MfQC failed: custom program error: 0xb
Transaction failed: Error processing Instruction 1: Unknown instruction error

2.1 关键代码解析

支持的chain_id命名及支持的action类型有：

	ActionGuardianSetUpdate Action = 0x01
	ActionContractUpgrade   Action = 0x02
	ActionTransfer          Action = 0x10

	// ChainIDSolana is the ChainID of Solana
	ChainIDSolana = 1
	// ChainIDEthereum is the ChainID of Ethereum
	ChainIDEthereum = 2
	// ChainIDTerra is the ChainID of Terra
	ChainIDTerra = 3

以 0x22557d54dfc8adb1a888478258f89abb4a11a7069c983e6db1bc14de6d6e7946 lockAssets交易为例： 会将相应的token发送到black hole: 0x0000000000000000000000000000000000000000 中 burn掉：

		if (isWrappedAsset[asset]) {
            WrappedAsset(asset).burn(msg.sender, amount);
            asset_chain = WrappedAsset(asset).assetChain();
            asset_address = WrappedAsset(asset).assetAddress();
        }

Solana端Wrapped Ether (Wormhole) token地址为：FeGn77dhg1KXRRFeSwwMiykZnZPw5JXW6naf2aQgZDQf

Solana端Wormhole合约中的mint交易为：https://solscan.io/tx/wwwFsn2cx69HPEg64iRErNHaUx4GbLt48vGSgFguAfgDBZtiYjFsXc6eH7CzEJuMv8RQ1UD41JZ1iMy5CYW5Hvr

以太坊端Wormhole:Solana Bridge合约地址为：

• https://etherscan.io/address/0xf92cd566ea4864356c5491c177a430c222d7e678

Solana端Wormhole合约地址为：

• WormT3McKhFJ2RkiGpdw9GKvNCrB2aB54gb2uV9MfQC

以太坊端Wormhole:Solana Bridge合约关键函数有：

• （1）submitVAA()，若action为0x10，即ActionTransfer，则将Solana中的资产通过Wormhole:Solana Bridge合约转移出来，对应的target_chain应设置为以太坊，若资产为以太坊ERC20 token（即token_chain=2），则直接将Solana Bridge合约中的ERC20 token转移到指定账号即可；若资产为其他链上的值，则在以太坊上根据token_chain和token_address在以太坊上创建相应的wrapped合约，往该合约mint或burn。

	if (token_chain != CHAIN_ID) {
            bytes32 token_address = data.toBytes32(71);
            bytes32 asset_id = keccak256(abi.encodePacked(token_chain, token_address));

            // if yes: mint to address
            // if no: create and mint
            address wrapped_asset = wrappedAssets[asset_id];
            if (wrapped_asset == address(0)) {
                uint8 asset_decimals = data.toUint8(103);
                wrapped_asset = deployWrappedAsset(asset_id, token_chain, token_address, asset_decimals);
            }

            WrappedAsset(wrapped_asset).mint(target_address, amount);
        } else {
            address token_address = data.toAddress(71 + 12);

            uint8 decimals = ERC20(token_address).decimals();

            // Readjust decimals if they've previously been truncated
            if (decimals > 9) {
                amount = amount.mul(10 ** uint256(decimals - 9));
            }
            IERC20(token_address).safeTransfer(target_address, amount);
        }

• （2）LockAssets()，用于将以太坊上的资产转移至Solana。

		if (isWrappedAsset[asset]) { //非以太坊上发行的token，通过wrapped合约销毁
            WrappedAsset(asset).burn(msg.sender, amount);
            asset_chain = WrappedAsset(asset).assetChain();
            asset_address = WrappedAsset(asset).assetAddress();
        } else { //以太坊上的ERC20 token，直接将相应金额转入本Solana Bridge合约。
            uint256 balanceBefore = IERC20(asset).balanceOf(address(this));
            IERC20(asset).safeTransferFrom(msg.sender, address(this), amount);
            uint256 balanceAfter = IERC20(asset).balanceOf(address(this));

            // The amount that was transferred in is the delta between balance before and after the transfer.
            // This is to properly handle tokens that charge a fee on transfer.
            amount = balanceAfter.sub(balanceBefore);

            // Decimal adjust amount - we keep the dust
            if (decimals > 9) {
                uint256 original_amount = amount;
                amount = amount.div(10 ** uint256(decimals - 9));

                if (refund_dust) {
                    IERC20(asset).safeTransfer(msg.sender, original_amount.mod(10 ** uint256(decimals - 9)));
                }

                decimals = 9;
            }

            require(balanceAfter.div(10 ** uint256(ERC20(asset).decimals() - 9))  {
            if t.source_chain == CHAIN_ID_SOLANA {
                // Solana (any) -> Ethereum (any)
                let transfer_key = Bridge::derive_transfer_id(
                    program_id,
                    &bridge_key,
                    t.asset.chain,
                    t.asset.address,
                    t.target_chain,
                    t.target_address,
                    t.source_address,
                    t.nonce,
                )?;
                accounts.push(AccountMeta::new(transfer_key, false))
            } 
            ......
        }

5）用户Agent监听4）中的Unlock签名，然后Aggregates & Publish Signatures 向以太坊发起SubmitVAA()交易。详细代码见：wormhole/bridge/pkg/solana/submitter.go。

// handleObservation processes a remote VAA observation, verifies it, checks whether the VAA has met quorum,
// and assembles and submits a valid VAA if possible.
func (p *Processor) handleObservation(ctx context.Context, m *gossipv1.SignedObservation) {
	// SECURITY: at this point, observations received from the p2p network are fully untrusted (all fields!)
	//
	// Note that observations are never tied to the (verified) p2p identity key - the p2p network
	// identity is completely decoupled from the guardian identity, p2p is just transport.
.......
}

				timeout, cancel := context.WithTimeout(ctx, 120*time.Second)
				res, err := c.SubmitVAA(timeout, &agentv1.SubmitVAARequest{Vaa: vaaBytes, SkipPreflight: e.skipPreflight})

相应的submitVAA() data 解析为：

0x01
00000001
0d

00a89efafc639d6fdb746a2a858d7f532bce4bda1314ae34b6ff68a7862d9ef8dc351989a274709e9dc2b2db324a39b8a19fc69add9f42c2e96dd049571bc5452b01
0112dbc46c6a5585829600d4acaaea44dc9f66df32173c2b49f4700df88499a1db4960219683e96541c8f53660228f05d01a5c8cce8fd16e6a0b90cc3d913475b300
02558eef0c8813b7634a8a73955c404ea3c91826ecdbc1272635900ed0b0aee101570c7ab06d41c783c913906b8a553777914e3b783611f93095b3efc0afe67f6801
03445546203c8d9505cee405fdc62ddd4bf1f20ba9e482a373bc9889c885ea7627060d3c08a0b37b570ca14fc7aae8afdbbf022409b2835e63c71c16a154e852c701
04743d7d1e43db5efb32264bdaecd4cad4a1c7ef767b338543f768b083a7b2fc0b198bbaf96ac1c10b53b48f6bb9ed2b2421a49559931af214b6cf0a930f92589301
050dd0655fb879741c94247bb3cf96616f21b35db519f030568b29965add9c7fa23a59de432dcc3f45ecf56399a25ff9d5663816cefe77930450c6ec7f6625472300
076d748bf0fde5cfb93a0dd51cdf98b305c7e44aa9501bad1758061a68715fe35b445b1e94d9058dbd5564805d3a637bd938501027444e93f491e509d458ed7aec01
08b4861bdd15ae8127175c8fe899018ccb43800188af3db27008865e153ed7f9681227778b4cbec7be5a519240730672a44f3ee22b1cf63828299fca157787b50601
0a711a8b9e8201ba17b3072af956217245018f2c9f26fb68bd2aa4e41de405503c6e35d5d73140b38d7e25f9da6c9c05925cfe3c6b60de35edb3380c98aa7a210301
0b8372a1a3a528ccdcb68e5bc3219c474df1e5b78f58ea971b62a6f3b96e408ba67b88863dd9694f5778e4cbe3697c24e78b3b76213ecb60513230ad737c6b214b01
0d8677291bd7e1a8b67a44e5f886a6247d9331a96d46a815fae1781ea72196965234782191666e02016083456cf33573bfa305844a414a4b695fd0ce42f7106e4300
10a1426d82f020df651b1165c8eb165bf6daaeb81e081aeede1490cdf1563fa65e604826f1e6f820b891bccfb0be451afef9a9f62cc92c255a666c8c3251f1bf3f01
12fba1acf05bf2b79eb610d7b979b898234d119351a3b4d1b4ba6918e4926ac6081974799460485b2444ec2f3ddca95426a2f28790c1bed850daf188e6c7e5025301

61405447
10

00016ed6
01
02
c544e189fb7a9ec43914e407145ac395144d22445066411844fd356817b7ea80000000000000000000000000
e0b2026e3db1606ef0beb764ccdf7b3cee30db4a
02
000000000000000000000000df574c24545e5ffecb9a659c229253d4111d87e1
08
0000000000000000000000000000000000000000000000000001614b2224f700

有：

>>> hex(388450300000000)
'0x1614b2224f700'

2.3 以太坊HUSD ERC20 token转移至Solana中HUSD示例

以太坊端交易为：https://etherscan.io/tx/0xffb94e1578a44730baac95782bf8f436ca7bdc5d6ca28c7b0811eb139a45fd83，转出账号为：0x47ed57f375d3dddae2ded7a6de522c35bc9419af。 Solana端交易为：https://explorer.solana.com/tx/4pn6CxjXYuA4nRUdUjXTK5yivwxSRSgDJJ9Rg37KNo5tQnKq61RWfxVmsmsqroUdS18NnQ7R1mz3yZbNajamS8SZ，转入账号为：CUAqsZjcsoaHJPfQTPLLvJRHpQuegguBwEzKehdztovT。

详细流程为： 1）用户调用LockAssets()将以太坊ERC20 token转移至Wormhole: Solana Bridge合约。 2）Validator监听LogTokensLocked event，并对其进行签名。

LogTokensLocked (uint8 target_chain, uint8 token_chain, uint8 token_decimals, index_topic_1 bytes32 token, index_topic_2 bytes32 sender, bytes32 recipient, uint256 amount, uint32 nonce)View Source
具体值为：
target_chain :
1
token_chain :
2
token_decimals :
8
recipient :
AA665DFB6CDD379DACB27DCCABDB9888128F6B47709FDA8809E72F1CA300901C
amount :
1709034375
nonce :
1409

// handleLockup processes a lockup received from a chain and instantiates our deterministic copy of the VAA. A lockup
// event may be received multiple times until it has been successfully completed.
func (p *Processor) handleLockup(ctx context.Context, k *common.ChainLock) {
	......
	// All nodes will create the exact same VAA and sign its digest.
	// Consensus is established on this digest.

	v := &vaa.VAA{
		Version:          vaa.SupportedVAAVersion,
		GuardianSetIndex: p.gs.Index,
		Signatures:       nil,
		Timestamp:        k.Timestamp,
		Payload: &vaa.BodyTransfer{
			Nonce:         k.Nonce,
			SourceChain:   k.SourceChain,
			TargetChain:   k.TargetChain,
			SourceAddress: k.SourceAddress,
			TargetAddress: k.TargetAddress,
			Asset: &vaa.AssetMeta{
				Chain:    k.TokenChain,
				Address:  k.TokenAddress,
				Decimals: k.TokenDecimals,
			},
			Amount: k.Amount,
		},
	}

	// Generate digest of the unsigned VAA.
	digest, err := v.SigningMsg()
	if err != nil {
		panic(err)
	}

	// Sign the digest using our node's guardian key.
	s, err := crypto.Sign(digest.Bytes(), p.gk)
	if err != nil {
		panic(err)
	}
	......
	p.broadcastSignature(v, s)
}

3）提交post_vaa()给Solana转账。

			else {
                // Foreign (native) -> Solana (wrapped)
                let wrapped_key = Bridge::derive_wrapped_asset_id(
                    program_id,
                    &bridge_key,
                    t.asset.chain,
                    t.asset.decimals,
                    t.asset.address,
                )?;
                let wrapped_meta_key =
                    Bridge::derive_wrapped_meta_id(program_id, &bridge_key, &wrapped_key)?;
                accounts.push(AccountMeta::new_readonly(spl_token::id(), false));
                accounts.push(AccountMeta::new(wrapped_key, false));
                accounts.push(AccountMeta::new(Pubkey::new(&t.target_address), false));
                accounts.push(AccountMeta::new(wrapped_meta_key, false));
            }

相应的log为：

Program WormT3McKhFJ2RkiGpdw9GKvNCrB2aB54gb2uV9MfQC invoke [1]
Instruction: PostVAA
Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA invoke [2]
Instruction: MintTo
Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA consumed 2779 of 104301 compute units
Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA success
deriving key
deploying contract
Program 11111111111111111111111111111111 invoke [2]
Program 11111111111111111111111111111111 success
Program WormT3McKhFJ2RkiGpdw9GKvNCrB2aB54gb2uV9MfQC consumed 124268 of 200000 compute units
Program WormT3McKhFJ2RkiGpdw9GKvNCrB2aB54gb2uV9MfQC success

3. Wormhole V2

Token Bridge 合约为：

NetworkWormhole token bridge contract addressEthereum Mainnet0x3ee18B2214AFF97000D974cf647E7C347E8fa585Solana MainnetwormDTUJ6AWPNvk59vGQbDvGJmqbDTdgWgAqcLBCgUb

Connected chain contracts合约为：

NetworkWormhole core contract addressEthereum Mainnet (Core)0x98f3c9e6E3fAce36bAAd05FE09d375Ef1464288BEthereum Mainnet (Impl)0x736d2a394f7810c17b3c6fed017d5bc7d60c077dBinance Smart Chain (Core)0x98f3c9e6E3fAce36bAAd05FE09d375Ef1464288BBinance Smart Chain (Impl)0x736d2a394f7810c17b3c6fed017d5bc7d60c077dSolana Mainnetworm2ZoG2kUd4vFXhvjh93UUH596ayRfgQ2MgjNMTthTerra Columbus-5terra1dq03ugtd40zu9hcgdzrsq6z2z4hwhc9tqk2uy5

Eth and BSC use the same deployer key, leading to identical addresses. This key has no privileges.

详细的Wormhole V2 token bridge流程参见： https://blog.mercurial.finance/how-to-transfer-eth-assets-to-solana-using-wormhole-v2-514e728dc4fc

详细的Wormhole V2 NFT bridge流程参见： https://decrypt.co/81764/ethereum-solana-wormhole-send-nfts-across-blockchains