add NFT Trading bridge

.gitignore

@@ -3,4 +3,5 @@ out/
 node_modules/
 yarn-error.log
 typechain-types/
-broadcast/ 
+broadcast/ 
+compose-dev.yaml

specs/bridges/nft_trading/readme.md

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+# Spec for NFT Trading Bridge
+
+## What does the bridge do? Why build it?
+
+This bridge enables user to  trading their NFT on the established Layer 1 NFT marketplaces, aka [OpenSea](https://opensea.io/), where users can list and purchase NFTs from Aztec L2 without revealing their L1 identities.
+In this way, the owner of one NFT owner is in private with the power of Aztec's zero knowledge rollup. So this bridge can enhance the secret characterist of Layer 1 user.
+
+
+## What protocol(s) does the bridge interact with ?
+The bridge interacts with [OpenSea](https://opensea.io/).
+
+## What is the flow of the bridge?
+
+The NFT bridge will design as a Wrap Erc721 Contract, that means everytime when the contract received a NFT, it will mint a relevant Wrapped NFT to this user, This Wrapped NFT can be transfer to Aztec L2, also can be unwrap and redeem the original NFT anytimes.
+
+The `BUY` flow as below:
+1. User A on Aztec chain bridge interface pay and buy an NFT on Opensea in Ethereum.
+2. The "Buy" order and relevant fee is send to L1 by Aztec's rollup.
+3. The bridge contract in L1 is triggered to interact with OpenSea protocol.
+4. Then the bridge contract own this NFT and Mint a Wrapped NFT for Aztec L2 to bridge.
+5. The User A On Aztec Owned this Wrapped NFT. 
+
+The `REDEEM` flow as below:
+1. User A hold an wrapped NFT in Aztec L2.
+2. He call the bridge to unwrapped and send the real NFT to a L1 address.
+3. The Bridge contract is trigged, and send the resl NFT to the user specifed address, and burn the wrapped NFT.
+
+### General Properties of convert(...) function
+  The `AztecTypes.AztecAsset calldata _inputAssetA` should be specificed as the Bridge's wrapped NFT. 
+  And the relevant function calling is encoded into the `_auxData` Info.
+  In the Bridge contract, the function will be routed by the decoded 
+`_auxData`.
+
+- The bridge is synchronous, and will always return `isAsync = false`.
+
+- The bridge uses `_auxData` to encode the target NFT, id, price.
+
+- The Bridge perform token pre-approvals to allow the `ROLLUP_PROCESSOR` to pull tokens from it.
+
+
+## Is the contract upgradeable?
+
+No, the bridge is immutable without any admin role.
+
+## Does the bridge maintain state?
+
+No, the bridge doesn't maintain a state.
+However, it keeps an insignificant amount of tokens (dust) in the bridge to reduce gas-costs of future transactions (in case the DUST was sent to the bridge).
+By having a dust, we don't need to do a `sstore` from `0` to `non-zero`.
+
+## Does this bridge maintain state? If so, what is stored and why?
+
+Yes, this bridge maintain the NFT bought from NFT to relevant user's private identity. 
+This state is a record for user to redeem their NFT asset.

src/bridges/nft-basic/NFTVault.sol

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+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2022 Aztec.
+pragma solidity >=0.8.4;
+
+import {IERC721} from "../../../lib/openzeppelin-contracts/contracts/interfaces/IERC721.sol";
+import {AztecTypes} from "../../../lib/rollup-encoder/src/libraries/AztecTypes.sol";
+import {ErrorLib} from "../base/ErrorLib.sol";
+import {BridgeBase} from "../base/BridgeBase.sol";
+import {AddressRegistry} from "../registry/AddressRegistry.sol";
+
+/**
+ * @title Basic NFT Vault for Aztec.
+ * @author Josh Crites, (@critesjosh on Github),  Aztec Team
+ * @notice You can use this contract to hold your NFTs on Aztec. Whoever holds the corresponding virutal asset note can withdraw the NFT.
+ * @dev This bridge demonstrates basic functionality for an NFT bridge. This may be extended to support more features.
+ */
+contract NFTVault is BridgeBase {
+    struct NFTAsset {
+        address collection;
+        uint256 tokenId;
+    }
+
+    AddressRegistry public immutable REGISTRY;
+
+    mapping(uint256 => NFTAsset) public nftAssets;
+
+    error InvalidVirtualAssetId();
+
+    event NFTDeposit(uint256 indexed virtualAssetId, address indexed collection, uint256 indexed tokenId);
+    event NFTWithdraw(uint256 indexed virtualAssetId, address indexed collection, uint256 indexed tokenId);
+
+    /**
+     * @notice Set the addresses of RollupProcessor and AddressRegistry
+     * @param _rollupProcessor Address of the RollupProcessor
+     * @param _registry Address of the AddressRegistry
+     */
+    constructor(address _rollupProcessor, address _registry) BridgeBase(_rollupProcessor) {
+        REGISTRY = AddressRegistry(_registry);
+    }
+
+    /**
+     * @notice Function for the first step of a NFT deposit, a NFT withdrawal, or transfer to another NFTVault.
+     * @dev This method can only be called from the RollupProcessor. The first step of the
+     * deposit flow returns a virutal asset note that will represent the NFT on Aztec. After the
+     * virutal asset note is received on Aztec, the user calls matchAndPull which deposits the NFT
+     * into Aztec and matches it with the virtual asset. When the virutal asset is sent to this function
+     * it is burned and the NFT is sent to the recipient passed in _auxData.
+     *
+     * @param _inputAssetA - ETH (Deposit) or VIRTUAL (Withdrawal)
+     * @param _outputAssetA - VIRTUAL (Deposit) or 0 ETH (Withdrawal)
+     * @param _totalInputValue - must be 1 wei (Deposit) or 1 VIRTUAL (Withdrawal)
+     * @param _interactionNonce - A globally unique identifier of this interaction/`convert(...)` call
+     *                              corresponding to the returned virtual asset id
+     * @param _auxData - corresponds to the Ethereum address id in the AddressRegistry.sol for withdrawals
+     * @return outputValueA - 1 VIRTUAL asset (Deposit) or 0 ETH (Withdrawal)
+     *
+     */
+
+    function convert(
+        AztecTypes.AztecAsset calldata _inputAssetA,
+        AztecTypes.AztecAsset calldata,
+        AztecTypes.AztecAsset calldata _outputAssetA,
+        AztecTypes.AztecAsset calldata,
+        uint256 _totalInputValue,
+        uint256 _interactionNonce,
+        uint64 _auxData,
+        address
+    )
+        external
+        payable
+        override (BridgeBase)
+        onlyRollup
+        returns (uint256 outputValueA, uint256 outputValueB, bool isAsync)
+    {
+        if (
+            _inputAssetA.assetType == AztecTypes.AztecAssetType.NOT_USED
+                || _inputAssetA.assetType == AztecTypes.AztecAssetType.ERC20
+        ) revert ErrorLib.InvalidInputA();
+        if (
+            _outputAssetA.assetType == AztecTypes.AztecAssetType.NOT_USED
+                || _outputAssetA.assetType == AztecTypes.AztecAssetType.ERC20
+        ) revert ErrorLib.InvalidOutputA();
+        if (_totalInputValue != 1) {
+            revert ErrorLib.InvalidInputAmount();
+        }
+        if (
+            _inputAssetA.assetType == AztecTypes.AztecAssetType.ETH
+                && _outputAssetA.assetType == AztecTypes.AztecAssetType.VIRTUAL
+        ) {
+            return (1, 0, false);
+        } else if (_inputAssetA.assetType == AztecTypes.AztecAssetType.VIRTUAL) {
+            NFTAsset memory token = nftAssets[_inputAssetA.id];
+            if (token.collection == address(0x0)) {
+                revert ErrorLib.InvalidInputA();
+            }
+
+            address to = REGISTRY.addresses(_auxData);
+            if (to == address(0x0)) {
+                revert ErrorLib.InvalidAuxData();
+            }
+            delete nftAssets[_inputAssetA.id];
+            emit NFTWithdraw(_inputAssetA.id, token.collection, token.tokenId);
+
+            if (_outputAssetA.assetType == AztecTypes.AztecAssetType.ETH) {
+                IERC721(token.collection).transferFrom(address(this), to, token.tokenId);
+                return (0, 0, false);
+            } else {
+                IERC721(token.collection).approve(to, token.tokenId);
+                NFTVault(to).matchAndPull(_interactionNonce, token.collection, token.tokenId);
+                return (1, 0, false);
+            }
+        }
+    }
+
+    /**
+     * @notice Function for the second step of a NFT deposit or for transfers from other NFTVaults.
+     * @dev For a deposit, this method is called by an Ethereum L1 account that owns the NFT to deposit.
+     * The user must approve this bridge contract to transfer the users NFT before this function
+     * is called. This function assumes the NFT contract complies with the ERC721 standard.
+     * For a transfer from another NFTVault, this method is called by the NFTVault that is sending the NFT.
+     *
+     * @param _virtualAssetId - the virutal asset id of the note returned in the deposit step of the convert function
+     * @param _collection - collection address of the NFT
+     * @param _tokenId - the token id of the NFT
+     */
+
+    function matchAndPull(uint256 _virtualAssetId, address _collection, uint256 _tokenId) external {
+        if (nftAssets[_virtualAssetId].collection != address(0x0)) {
+            revert InvalidVirtualAssetId();
+        }
+        nftAssets[_virtualAssetId] = NFTAsset({collection: _collection, tokenId: _tokenId});
+        IERC721(_collection).transferFrom(msg.sender, address(this), _tokenId);
+        emit NFTDeposit(_virtualAssetId, _collection, _tokenId);
+    }
+}

src/bridges/nft_trading/NFTVault.sol

@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2022 Aztec.
+pragma solidity >=0.8.4;
+
+import {IERC721} from "../../../lib/openzeppelin-contracts/contracts/interfaces/IERC721.sol";
+import {AztecTypes} from "../../../lib/rollup-encoder/src/libraries/AztecTypes.sol";
+import {ErrorLib} from "../base/ErrorLib.sol";
+import {BridgeBase} from "../base/BridgeBase.sol";
+import {AddressRegistry} from "../registry/AddressRegistry.sol";
+
+/**
+ * @title Basic NFT Vault for Aztec.
+ * @author Josh Crites, (@critesjosh on Github),  Aztec Team
+ * @notice You can use this contract to hold your NFTs on Aztec. Whoever holds the corresponding virutal asset note can withdraw the NFT.
+ * @dev This bridge demonstrates basic functionality for an NFT bridge. This may be extended to support more features.
+ */
+contract NFTVault is BridgeBase {
+    struct NFTAsset {
+        address collection;
+        uint256 tokenId;
+    }
+
+    AddressRegistry public immutable REGISTRY;
+
+    mapping(uint256 => NFTAsset) public nftAssets;
+
+    error InvalidVirtualAssetId();
+
+    event NFTDeposit(uint256 indexed virtualAssetId, address indexed collection, uint256 indexed tokenId);
+    event NFTWithdraw(uint256 indexed virtualAssetId, address indexed collection, uint256 indexed tokenId);
+
+    /**
+     * @notice Set the addresses of RollupProcessor and AddressRegistry
+     * @param _rollupProcessor Address of the RollupProcessor
+     * @param _registry Address of the AddressRegistry
+     */
+    constructor(address _rollupProcessor, address _registry) BridgeBase(_rollupProcessor) {
+        REGISTRY = AddressRegistry(_registry);
+    }
+
+    /**
+     * @notice Function for the first step of a NFT deposit, a NFT withdrawal, or transfer to another NFTVault.
+     * @dev This method can only be called from the RollupProcessor. The first step of the
+     * deposit flow returns a virutal asset note that will represent the NFT on Aztec. After the
+     * virutal asset note is received on Aztec, the user calls matchAndPull which deposits the NFT
+     * into Aztec and matches it with the virtual asset. When the virutal asset is sent to this function
+     * it is burned and the NFT is sent to the recipient passed in _auxData.
+     *
+     * @param _inputAssetA - ETH (Deposit) or VIRTUAL (Withdrawal)
+     * @param _outputAssetA - VIRTUAL (Deposit) or 0 ETH (Withdrawal)
+     * @param _totalInputValue - must be 1 wei (Deposit) or 1 VIRTUAL (Withdrawal)
+     * @param _interactionNonce - A globally unique identifier of this interaction/`convert(...)` call
+     *                              corresponding to the returned virtual asset id
+     * @param _auxData - corresponds to the Ethereum address id in the AddressRegistry.sol for withdrawals
+     * @return outputValueA - 1 VIRTUAL asset (Deposit) or 0 ETH (Withdrawal)
+     *
+     */
+
+    function convert(
+        AztecTypes.AztecAsset calldata _inputAssetA,
+        AztecTypes.AztecAsset calldata,
+        AztecTypes.AztecAsset calldata _outputAssetA,
+        AztecTypes.AztecAsset calldata,
+        uint256 _totalInputValue,
+        uint256 _interactionNonce,
+        uint64 _auxData,
+        address
+    )
+        external
+        payable
+        override (BridgeBase)
+        onlyRollup
+        returns (uint256 outputValueA, uint256 outputValueB, bool isAsync)
+    {
+        if (
+            _inputAssetA.assetType == AztecTypes.AztecAssetType.NOT_USED
+                || _inputAssetA.assetType == AztecTypes.AztecAssetType.ERC20
+        ) revert ErrorLib.InvalidInputA();
+        if (
+            _outputAssetA.assetType == AztecTypes.AztecAssetType.NOT_USED
+                || _outputAssetA.assetType == AztecTypes.AztecAssetType.ERC20
+        ) revert ErrorLib.InvalidOutputA();
+        if (_totalInputValue != 1) {
+            revert ErrorLib.InvalidInputAmount();
+        }
+        if (
+            _inputAssetA.assetType == AztecTypes.AztecAssetType.ETH
+                && _outputAssetA.assetType == AztecTypes.AztecAssetType.VIRTUAL
+        ) {
+            return (1, 0, false);
+        } else if (_inputAssetA.assetType == AztecTypes.AztecAssetType.VIRTUAL) {
+            NFTAsset memory token = nftAssets[_inputAssetA.id];
+            if (token.collection == address(0x0)) {
+                revert ErrorLib.InvalidInputA();
+            }
+
+            address to = REGISTRY.addresses(_auxData);
+            if (to == address(0x0)) {
+                revert ErrorLib.InvalidAuxData();
+            }
+            delete nftAssets[_inputAssetA.id];
+            emit NFTWithdraw(_inputAssetA.id, token.collection, token.tokenId);
+
+            if (_outputAssetA.assetType == AztecTypes.AztecAssetType.ETH) {
+                IERC721(token.collection).transferFrom(address(this), to, token.tokenId);
+                return (0, 0, false);
+            } else {
+                IERC721(token.collection).approve(to, token.tokenId);
+                NFTVault(to).matchAndPull(_interactionNonce, token.collection, token.tokenId);
+                return (1, 0, false);
+            }
+        }
+    }
+
+    /**
+     * @notice Function for the second step of a NFT deposit or for transfers from other NFTVaults.
+     * @dev For a deposit, this method is called by an Ethereum L1 account that owns the NFT to deposit.
+     * The user must approve this bridge contract to transfer the users NFT before this function
+     * is called. This function assumes the NFT contract complies with the ERC721 standard.
+     * For a transfer from another NFTVault, this method is called by the NFTVault that is sending the NFT.
+     *
+     * @param _virtualAssetId - the virutal asset id of the note returned in the deposit step of the convert function
+     * @param _collection - collection address of the NFT
+     * @param _tokenId - the token id of the NFT
+     */
+
+    function matchAndPull(uint256 _virtualAssetId, address _collection, uint256 _tokenId) external {
+        if (nftAssets[_virtualAssetId].collection != address(0x0)) {
+            revert InvalidVirtualAssetId();
+        }
+        nftAssets[_virtualAssetId] = NFTAsset({collection: _collection, tokenId: _tokenId});
+        IERC721(_collection).transferFrom(msg.sender, address(this), _tokenId);
+        emit NFTDeposit(_virtualAssetId, _collection, _tokenId);
+    }
+}