Merge GSNContext into GSNRecipient (#1906)
* Merge GSNContext into GSNRecipient
* Update GSNRecipient.test.js
* Update GSNRecipient.sol
* Make GSNRecipient inherit from Context
(cherry picked from commit 1efa9f6281)
release-v2.4.0
Nicolás Venturo
6 years ago
committed by
Francisco Giordano
parent
5f1d8e19da
commit
dba4d5023d
@ -1,88 +0,0 @@ |
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pragma solidity ^0.5.0; |
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import "./Context.sol"; |
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/** |
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* @dev Enables GSN support on `Context` contracts by recognizing calls from |
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* RelayHub and extracting the actual sender and call data from the received |
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* calldata. |
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* |
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* > This contract does not perform all required tasks to implement a GSN |
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* recipient contract: end users should use `GSNRecipient` instead. |
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*/ |
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contract GSNContext is Context { |
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address internal _relayHub = 0xD216153c06E857cD7f72665E0aF1d7D82172F494; |
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event RelayHubChanged(address indexed oldRelayHub, address indexed newRelayHub); |
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constructor() internal { |
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// solhint-disable-previous-line no-empty-blocks |
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} |
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function _upgradeRelayHub(address newRelayHub) internal { |
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address currentRelayHub = _relayHub; |
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require(newRelayHub != address(0), "GSNContext: new RelayHub is the zero address"); |
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require(newRelayHub != currentRelayHub, "GSNContext: new RelayHub is the current one"); |
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emit RelayHubChanged(currentRelayHub, newRelayHub); |
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_relayHub = newRelayHub; |
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} |
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// Overrides for Context's functions: when called from RelayHub, sender and |
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// data require some pre-processing: the actual sender is stored at the end |
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// of the call data, which in turns means it needs to be removed from it |
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// when handling said data. |
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function _msgSender() internal view returns (address) { |
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if (msg.sender != _relayHub) { |
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return msg.sender; |
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} else { |
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return _getRelayedCallSender(); |
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} |
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} |
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function _msgData() internal view returns (bytes memory) { |
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if (msg.sender != _relayHub) { |
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return msg.data; |
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} else { |
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return _getRelayedCallData(); |
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} |
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} |
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function _getRelayedCallSender() private pure returns (address result) { |
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// We need to read 20 bytes (an address) located at array index msg.data.length - 20. In memory, the array |
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// is prefixed with a 32-byte length value, so we first add 32 to get the memory read index. However, doing |
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// so would leave the address in the upper 20 bytes of the 32-byte word, which is inconvenient and would |
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// require bit shifting. We therefore subtract 12 from the read index so the address lands on the lower 20 |
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// bytes. This can always be done due to the 32-byte prefix. |
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// The final memory read index is msg.data.length - 20 + 32 - 12 = msg.data.length. Using inline assembly is the |
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// easiest/most-efficient way to perform this operation. |
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// These fields are not accessible from assembly |
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bytes memory array = msg.data; |
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uint256 index = msg.data.length; |
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// solhint-disable-next-line no-inline-assembly |
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assembly { |
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// Load the 32 bytes word from memory with the address on the lower 20 bytes, and mask those. |
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result := and(mload(add(array, index)), 0xffffffffffffffffffffffffffffffffffffffff) |
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} |
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return result; |
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} |
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function _getRelayedCallData() private pure returns (bytes memory) { |
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// RelayHub appends the sender address at the end of the calldata, so in order to retrieve the actual msg.data, |
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// we must strip the last 20 bytes (length of an address type) from it. |
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uint256 actualDataLength = msg.data.length - 20; |
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bytes memory actualData = new bytes(actualDataLength); |
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for (uint256 i = 0; i < actualDataLength; ++i) { |
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actualData[i] = msg.data[i]; |
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} |
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return actualData; |
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} |
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} |
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@ -1,46 +0,0 @@ |
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pragma solidity ^0.5.0; |
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import "./ContextMock.sol"; |
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import "../GSN/GSNContext.sol"; |
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import "../GSN/IRelayRecipient.sol"; |
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// By inheriting from GSNContext, Context's internal functions are overridden automatically |
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contract GSNContextMock is ContextMock, GSNContext, IRelayRecipient { |
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function getHubAddr() public view returns (address) { |
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return _relayHub; |
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} |
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function acceptRelayedCall( |
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address, |
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address, |
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bytes calldata, |
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uint256, |
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uint256, |
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uint256, |
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uint256, |
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bytes calldata, |
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uint256 |
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) |
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external |
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view |
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returns (uint256, bytes memory) |
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{ |
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return (0, ""); |
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} |
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function preRelayedCall(bytes calldata) external returns (bytes32) { |
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// solhint-disable-previous-line no-empty-blocks |
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} |
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function postRelayedCall(bytes calldata, bool, uint256, bytes32) external { |
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// solhint-disable-previous-line no-empty-blocks |
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} |
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function getRelayHub() public view returns (address) { |
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return _relayHub; |
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} |
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function upgradeRelayHub(address newRelayHub) public { |
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return _upgradeRelayHub(newRelayHub); |
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} |
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} |
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@ -1,78 +0,0 @@ |
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const { BN, constants, expectEvent, expectRevert } = require('openzeppelin-test-helpers'); |
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const { ZERO_ADDRESS } = constants; |
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const gsn = require('@openzeppelin/gsn-helpers'); |
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const GSNContextMock = artifacts.require('GSNContextMock'); |
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const ContextMockCaller = artifacts.require('ContextMockCaller'); |
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const { shouldBehaveLikeRegularContext } = require('./Context.behavior'); |
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contract('GSNContext', function ([_, deployer, sender, newRelayHub]) { |
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beforeEach(async function () { |
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this.context = await GSNContextMock.new(); |
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this.caller = await ContextMockCaller.new(); |
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}); |
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describe('get/set RelayHub', function () { |
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const singletonRelayHub = '0xD216153c06E857cD7f72665E0aF1d7D82172F494'; |
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it('initially returns the singleton instance address', async function () { |
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expect(await this.context.getRelayHub()).to.equal(singletonRelayHub); |
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}); |
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it('can be upgraded to a new RelayHub', async function () { |
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const { logs } = await this.context.upgradeRelayHub(newRelayHub); |
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expectEvent.inLogs(logs, 'RelayHubChanged', { oldRelayHub: singletonRelayHub, newRelayHub }); |
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}); |
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it('cannot upgrade to the same RelayHub', async function () { |
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await expectRevert( |
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this.context.upgradeRelayHub(singletonRelayHub), |
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'GSNContext: new RelayHub is the current one' |
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); |
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}); |
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it('cannot upgrade to the zero address', async function () { |
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await expectRevert(this.context.upgradeRelayHub(ZERO_ADDRESS), 'GSNContext: new RelayHub is the zero address'); |
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}); |
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context('with new RelayHub', function () { |
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beforeEach(async function () { |
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await this.context.upgradeRelayHub(newRelayHub); |
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}); |
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it('returns the new instance address', async function () { |
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expect(await this.context.getRelayHub()).to.equal(newRelayHub); |
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}); |
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}); |
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}); |
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context('when called directly', function () { |
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shouldBehaveLikeRegularContext(sender); |
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}); |
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context('when receiving a relayed call', function () { |
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beforeEach(async function () { |
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await gsn.fundRecipient(web3, { recipient: this.context.address }); |
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}); |
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describe('msgSender', function () { |
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it('returns the relayed transaction original sender', async function () { |
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const { tx } = await this.context.msgSender({ from: sender, useGSN: true }); |
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await expectEvent.inTransaction(tx, GSNContextMock, 'Sender', { sender }); |
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}); |
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}); |
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describe('msgData', function () { |
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it('returns the relayed transaction original data', async function () { |
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const integerValue = new BN('42'); |
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const stringValue = 'OpenZeppelin'; |
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const callData = this.context.contract.methods.msgData(integerValue.toString(), stringValue).encodeABI(); |
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// The provider doesn't properly estimate gas for a relayed call, so we need to manually set a higher value
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const { tx } = await this.context.msgData(integerValue, stringValue, { gas: 1000000, useGSN: true }); |
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await expectEvent.inTransaction(tx, GSNContextMock, 'Data', { data: callData, integerValue, stringValue }); |
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}); |
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}); |
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}); |
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}); |
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