- Production Mainnet: auditor.mobilecoin.foundation
- Production Testnet: auditor.test.mobilecoin.com
- Staging Mainnet: auditor.stage.main.mobilecoin.com
- Staging Testnet: auditor.stage.test.mobilecoin.com
This is a service which provides a gRPC API for auditing mints and burns on the MobileCoin blockchain, and optionally correlating them with deposits and withdrawals on a Gnosis Safe.
The reserve auditor stores its audit information in a SQLite database, and provides a gRPC for querying this database. It also provides some Prometheus metrics to ease automated monitoring.
Full use of the Reserve Auditor requires a local ledger of the mobilecoin network, a scanning layer to ingest the contents of the local ledger, an http server to serve the results to http://localhost:3000, and a front end to visualize the data. See BUILD.md for more information
The reserve auditor supports syncing data from a Gnosis safe. It uses the Gnosis transaction service API to get the data. This service is operated by Gnosis, and is available for ETH main net and Sepolia, an ETH test net.
Mints on the MobileCoin blockchain are expected to correlate with a deposit to a safe. The expected process is:
- A deposit of the appropriate backing token is made to the safe using a standard Ethereum transaction.
- A MintTx is then submitted to the MobileCoin blockchain, embedding the deposit transaction hash in the nonce of the MobileCoin MintTx. The nonce allows linking the MobileCoin mint to the Gnosis safe deposit.
Similarly, burns on the MobileCoin blockchain are expected to correlate with a withdrawal from a safe. The expected process is:
- A transaction on the MobileCoin blockchain that moves the desired token to the burn address is issued.
- A batched transaction is issued to the Ethereum blockchain. The batched transaction needs to contain two transactions:
- A transaction that moves the desired token out of the safe
- A transaction to an auxiliary contract (see more details below) that is used to link withdrawal to the MobileCoin burn.
Gnosis deposits are easily linked to the matching MobileCoin mints via the Ethereum transaction hash. Linking withdrawals is more difficult since standard Ethereum transactions do not have a way of including metadata. In an ideal world we would've had the option of including the MobileCoin burn transaction TxOut public key in the Ethereum withdrawal transaction, but there is no easy way to do that. The solution we came up with is to deploy an "auxiliary contract", who has a single function that accepts arbitrary metadata bytes, and use that as part of a Gnosis batched transfer to include extra data in addition to the token transfer. Such contract can be seen here and is deployed to the Sepolia network.
The first step is to decide which asset you are going to use on the Ethereum blockchain, and get some ETH (for paying gas fees) and some of this test asset. For testing purposes we have used seUSD (Sepolia eUSD) - https://sepolia.etherscan.io/token/0xfdc112c39d0fafa45ec8b2ca9e46dfab43b41575. You need to get some ETH, and some of this asset. Google around to find working faucets.
To play around with Gnosis auditing the first step is to create a safe. This can be done on https://app.safe.global/ Once the safe is created, it will be assigned an address on the Ethereum blockchain. This assumes you have a wallet that your browser can connect to such as MetaMask. Note that creating a Gnosis Safe requires submitting a transaction to the Ethereum blockchain, so your wallet will need to have some ETH to pay the gas fees.
The Ethereum network you are testing with will need to have the metadata contract deployed. For the Sepolia test network, this was already done and assigned the address 0xF6970481dd09494099b5A2559E05Fa1Db6D6660B.
You will also need to know the 4 byte signature of the metadata contract emitBytes function. For the contract mentioned above, this is AUX_BURN_FUNCTION_SIG.to_vec() (since this is derived from the function signature, it should be the same for all unmodified deployments of this contract).
Depositing to the safe is as simple as sending a standard Ethereum transaction that moves your desired token (seUSD in this example) into the safe's address.
Once the Gnosis transaction service notices the transaction and the auditor syncs it you should see a log message similar to this:
2022-06-21 20:40:42.785395662 UTC INFO Processing gnosis safe deposit: EthereumTransfer { from: EthAddr("0xdc079a637a1417020916FfB8a39fF5a2801A0F07"), to: EthAddr("0xeC018400FFe5Ad6E0B42Aa592Ee1CF6092972dEe"), token_addr: Some(EthAddr("0xeC76FbFD75481839e456C4cb2cd23cda813f19B1")), tx_hash: EthTxHash("0x744372bb82b2d0f0e7b2722d163ffef97656562b40cc7fad9a1809d14aaf626a"), tx_type: "ERC20_TRANSFER", value: JsonU64(10000000000000000000) }, mc.app: mc-reserve-auditor, mc.module: mc_reserve_auditor::gnosis::sync, mc.src: reserve-auditor/src/gnosis/sync.rs:128
Withdrawal is slightly move involved since you will need to construct a multi-transaction that both moves the token out of the safe and transacts with the auxiliary metadata contracts to record the matching MobileCoin burn TxOut public key.
The steps to do that are:
- On the Gnosis safe web app click
Appsand then select theTransaction Builderapplication. - We will first construct the transaction that moves the
seUSDtoken. In theEnter Address or ENS Nameyou need to put the contract address, which forseUSDon Sepolia is0xfdc112c39d0fafa45ec8b2ca9e46dfab43b41575 - Under
Enter ABIyou need to put the contract ABI
View Contract
[
{
"constant": true,
"inputs": [],
"name": "name",
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"payable": false,
"stateMutability": "view",
"type": "function"
},
{
"constant": false,
"inputs": [{ "name": "_upgradedAddress", "type": "address" }],
"name": "deprecate",
"outputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "function"
},
{
"constant": false,
"inputs": [
{ "name": "_spender", "type": "address" },
{ "name": "_value", "type": "uint256" }
],
"name": "approve",
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"payable": false,
"stateMutability": "nonpayable",
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{
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"stateMutability": "view",
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},
{
"constant": false,
"inputs": [{ "name": "_evilUser", "type": "address" }],
"name": "addBlackList",
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{
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{
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"inputs": [
{ "name": "_from", "type": "address" },
{ "name": "_to", "type": "address" },
{ "name": "_value", "type": "uint256" }
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"name": "transferFrom",
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{
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{
"constant": true,
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"name": "balances",
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{
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{
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{
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{
"constant": false,
"inputs": [],
"name": "unpause",
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"stateMutability": "nonpayable",
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{
"constant": true,
"inputs": [{ "name": "_maker", "type": "address" }],
"name": "getBlackListStatus",
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"stateMutability": "view",
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{
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{ "name": "", "type": "address" },
{ "name": "", "type": "address" }
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{
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{
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"name": "balanceOf",
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"stateMutability": "view",
"type": "function"
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{
"constant": false,
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{
"constant": true,
"inputs": [],
"name": "getOwner",
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{
"constant": true,
"inputs": [],
"name": "owner",
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"stateMutability": "view",
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},
{
"constant": true,
"inputs": [],
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{
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{ "name": "_to", "type": "address" },
{ "name": "_value", "type": "uint256" }
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"name": "transfer",
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"stateMutability": "nonpayable",
"type": "function"
},
{
"constant": false,
"inputs": [
{ "name": "newBasisPoints", "type": "uint256" },
{ "name": "newMaxFee", "type": "uint256" }
],
"name": "setParams",
"outputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "function"
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{
"constant": false,
"inputs": [{ "name": "amount", "type": "uint256" }],
"name": "issue",
"outputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "function"
},
{
"constant": false,
"inputs": [{ "name": "amount", "type": "uint256" }],
"name": "redeem",
"outputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "function"
},
{
"constant": true,
"inputs": [
{ "name": "_owner", "type": "address" },
{ "name": "_spender", "type": "address" }
],
"name": "allowance",
"outputs": [{ "name": "remaining", "type": "uint256" }],
"payable": false,
"stateMutability": "view",
"type": "function"
},
{
"constant": true,
"inputs": [],
"name": "basisPointsRate",
"outputs": [{ "name": "", "type": "uint256" }],
"payable": false,
"stateMutability": "view",
"type": "function"
},
{
"constant": true,
"inputs": [{ "name": "", "type": "address" }],
"name": "isBlackListed",
"outputs": [{ "name": "", "type": "bool" }],
"payable": false,
"stateMutability": "view",
"type": "function"
},
{
"constant": false,
"inputs": [{ "name": "_clearedUser", "type": "address" }],
"name": "removeBlackList",
"outputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "function"
},
{
"constant": true,
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"name": "MAX_UINT",
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"type": "function"
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{
"constant": false,
"inputs": [{ "name": "newOwner", "type": "address" }],
"name": "transferOwnership",
"outputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "function"
},
{
"constant": false,
"inputs": [{ "name": "_blackListedUser", "type": "address" }],
"name": "destroyBlackFunds",
"outputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "function"
},
{
"inputs": [
{ "name": "_initialSupply", "type": "uint256" },
{ "name": "_name", "type": "string" },
{ "name": "_symbol", "type": "string" },
{ "name": "_decimals", "type": "uint256" }
],
"payable": false,
"stateMutability": "nonpayable",
"type": "constructor"
},
{
"anonymous": false,
"inputs": [{ "indexed": false, "name": "amount", "type": "uint256" }],
"name": "Issue",
"type": "event"
},
{
"anonymous": false,
"inputs": [{ "indexed": false, "name": "amount", "type": "uint256" }],
"name": "Redeem",
"type": "event"
},
{
"anonymous": false,
"inputs": [{ "indexed": false, "name": "newAddress", "type": "address" }],
"name": "Deprecate",
"type": "event"
},
{
"anonymous": false,
"inputs": [
{ "indexed": false, "name": "feeBasisPoints", "type": "uint256" },
{ "indexed": false, "name": "maxFee", "type": "uint256" }
],
"name": "Params",
"type": "event"
},
{
"anonymous": false,
"inputs": [
{ "indexed": false, "name": "_blackListedUser", "type": "address" },
{ "indexed": false, "name": "_balance", "type": "uint256" }
],
"name": "DestroyedBlackFunds",
"type": "event"
},
{
"anonymous": false,
"inputs": [{ "indexed": false, "name": "_user", "type": "address" }],
"name": "AddedBlackList",
"type": "event"
},
{
"anonymous": false,
"inputs": [{ "indexed": false, "name": "_user", "type": "address" }],
"name": "RemovedBlackList",
"type": "event"
},
{
"anonymous": false,
"inputs": [
{ "indexed": true, "name": "owner", "type": "address" },
{ "indexed": true, "name": "spender", "type": "address" },
{ "indexed": false, "name": "value", "type": "uint256" }
],
"name": "Approval",
"type": "event"
},
{
"anonymous": false,
"inputs": [
{ "indexed": true, "name": "from", "type": "address" },
{ "indexed": true, "name": "to", "type": "address" },
{ "indexed": false, "name": "value", "type": "uint256" }
],
"name": "Transfer",
"type": "event"
},
{ "anonymous": false, "inputs": [], "name": "Pause", "type": "event" },
{ "anonymous": false, "inputs": [], "name": "Unpause", "type": "event" }
]https://sepolia.etherscan.io/address/0xfdc112c39d0fafa45ec8b2ca9e46dfab43b41575#code contains a Contract ABI section that you copy-paste from.