Add acknowledgement for irrevocable actions using EIP712 (#599)

* Require signed user ack

* Added test

* Small fix

* WIP

* Cleanup

* More cleanup

* Cleaned up tests

* Skip acknowledgement tests in coverage

* Test fix

* Merge fix

contracts/libraries/TokenLib.sol

@@ -12,6 +12,24 @@ library TokenLib {
 
     using SafeMath for uint256;
 
+    struct EIP712Domain {
+        string  name;
+        uint256 chainId;
+        address verifyingContract;
+    }
+
+    struct Acknowledgment {
+        string text;
+    }
+
+    bytes32 constant EIP712DOMAIN_TYPEHASH = keccak256(
+        "EIP712Domain(string name,uint256 chainId,address verifyingContract)"
+    );
+
+    bytes32 constant ACK_TYPEHASH = keccak256(
+        "Acknowledgment(string text)"
+    );
+
     bytes32 internal constant WHITELIST = "WHITELIST";
     bytes32 internal constant INVESTORSKEY = 0xdf3a8dd24acdd05addfc6aeffef7574d2de3f844535ec91e8e0f3e45dba96731; //keccak256(abi.encodePacked("INVESTORS"))
 
@@ -26,6 +44,80 @@ library TokenLib {
     // Emit when the budget allocated to a module is changed
     event ModuleBudgetChanged(uint8[] _moduleTypes, address _module, uint256 _oldBudget, uint256 _budget);
 
+    function hash(EIP712Domain memory _eip712Domain) internal pure returns (bytes32) {
+        return keccak256(
+            abi.encode(
+                EIP712DOMAIN_TYPEHASH,
+                keccak256(bytes(_eip712Domain.name)),
+                _eip712Domain.chainId,
+                _eip712Domain.verifyingContract
+            )
+        );
+    }
+
+    function hash(Acknowledgment memory _ack) internal pure returns (bytes32) {
+        return keccak256(abi.encode(ACK_TYPEHASH, keccak256(bytes(_ack.text))));
+    }
+
+    function recoverFreezeIssuanceAckSigner(bytes memory _signature) public view returns (address) {
+        Acknowledgment memory ack = Acknowledgment("I acknowledge that freezing Issuance is a permanent and irrevocable change");
+        return extractSigner(ack, _signature);
+    }
+
+    function recoverDisableControllerAckSigner(bytes memory _signature) public view returns (address) {
+        Acknowledgment memory ack = Acknowledgment("I acknowledge that disabling controller is a permanent and irrevocable change");
+        return extractSigner(ack, _signature);
+    }
+
+    function extractSigner(Acknowledgment memory _ack, bytes memory _signature) internal view returns (address) {
+        bytes32 r;
+        bytes32 s;
+        uint8 v;
+
+        // Check the signature length
+        if (_signature.length != 65) {
+            return (address(0));
+        }
+
+        // Divide the signature in r, s and v variables
+        // ecrecover takes the signature parameters, and the only way to get them
+        // currently is to use assembly.
+        // solhint-disable-next-line no-inline-assembly
+        assembly {
+            r := mload(add(_signature, 0x20))
+            s := mload(add(_signature, 0x40))
+            v := byte(0, mload(add(_signature, 0x60)))
+        }
+
+        // Version of signature should be 27 or 28, but 0 and 1 are also possible versions
+        if (v < 27) {
+            v += 27;
+        }
+
+        // If the version is correct return the signer address
+        if (v != 27 && v != 28) {
+            return (address(0));
+        }
+
+        bytes32 DOMAIN_SEPARATOR = hash(
+            EIP712Domain(
+                {
+                    name: "Polymath",
+                    chainId: 1,
+                    verifyingContract: address(this)
+                }
+            )
+        );
+
+        // Note: we need to use `encodePacked` here instead of `encode`.
+        bytes32 digest = keccak256(abi.encodePacked(
+            "\x19\x01",
+            DOMAIN_SEPARATOR,
+            hash(_ack)
+        ));
+        return ecrecover(digest, v, r, s);
+    }
+
     /**
     * @notice Archives a module attached to the SecurityToken
     * @param _moduleData Storage data

contracts/tokens/SecurityToken.sol

@@ -12,7 +12,6 @@ import "../interfaces/token/IERC1594.sol";
 import "../interfaces/token/IERC1643.sol";
 import "../interfaces/token/IERC1644.sol";
 import "../interfaces/IModuleRegistry.sol";
-import "../interfaces/IFeatureRegistry.sol";
 import "../interfaces/ITransferManager.sol";
 import "openzeppelin-solidity/contracts/ownership/Ownable.sol";
 import "openzeppelin-solidity/contracts/utils/ReentrancyGuard.sol";
@@ -115,11 +114,6 @@ contract SecurityToken is ERC20, ERC20Detailed, Ownable, ReentrancyGuard, Securi
         _;
     }
 
-    modifier isEnabled(string memory _nameKey) {
-        require(IFeatureRegistry(featureRegistry).getFeatureStatus(_nameKey));
-        _;
-    }
-
     /**
      * @notice constructor
      * @param _name Name of the SecurityToken
@@ -485,7 +479,8 @@ contract SecurityToken is ERC20, ERC20Detailed, Ownable, ReentrancyGuard, Securi
      * @notice Permanently freeze issuance of this security token.
      * @dev It MUST NOT be possible to increase `totalSuppy` after this function is called.
      */
-    function freezeIssuance() external isIssuanceAllowed isEnabled("freezeIssuanceAllowed") onlyOwner {
+    function freezeIssuance(bytes calldata _signature) external isIssuanceAllowed onlyOwner {
+        require(owner() == TokenLib.recoverFreezeIssuanceAckSigner(_signature), "Owner did not sign");
         issuance = false;
         /*solium-disable-next-line security/no-block-members*/
         emit FreezeIssuance();
@@ -614,7 +609,8 @@ contract SecurityToken is ERC20, ERC20Detailed, Ownable, ReentrancyGuard, Securi
      * @notice Used by the issuer to permanently disable controller functionality
      * @dev enabled via feature switch "disableControllerAllowed"
      */
-    function disableController() external isEnabled("disableControllerAllowed") onlyOwner {
+    function disableController(bytes calldata _signature) external onlyOwner {
+        require(owner() == TokenLib.recoverDisableControllerAckSigner(_signature), "Owner did not sign");
         require(isControllable());
         controllerDisabled = true;
         delete controller;
@@ -768,7 +764,6 @@ contract SecurityToken is ERC20, ERC20Detailed, Ownable, ReentrancyGuard, Securi
     function updateFromRegistry() public onlyOwner {
         moduleRegistry = PolymathRegistry(polymathRegistry).getAddress("ModuleRegistry");
         securityTokenRegistry = PolymathRegistry(polymathRegistry).getAddress("SecurityTokenRegistry");
-        featureRegistry = PolymathRegistry(polymathRegistry).getAddress("FeatureRegistry");
         polyToken = PolymathRegistry(polymathRegistry).getAddress("PolyToken");
     }
 }

contracts/tokens/SecurityTokenStorage.sol

@@ -53,7 +53,6 @@ contract SecurityTokenStorage {
     address public polymathRegistry;
     address public moduleRegistry;
     address public securityTokenRegistry;
-    address public featureRegistry;
     address public polyToken;
     address public delegate;
     // Address of the data store used to store shared data

test/helpers/signData.js

@@ -1,4 +1,5 @@
 const Web3 = require("web3");
+//const sigUtil = require('eth-sig-util')
 let BN = Web3.utils.BN;
 
 function getSignSTMData(tmAddress, nonce, validFrom, expiry, fromAddress, toAddress, amount, pk) {
@@ -32,6 +33,90 @@ function getSignSTMData(tmAddress, nonce, validFrom, expiry, fromAddress, toAddr
     return data;
 }
 
+async function getFreezeIssuanceAck(stAddress, from) {
+    const typedData = {
+        types: {
+            EIP712Domain: [
+                { name: 'name', type: 'string' },
+                { name: 'chainId', type: 'uint256' },
+                { name: 'verifyingContract', type: 'address' }
+            ],
+            Acknowledgment: [
+                { name: 'text', type: 'string' }
+            ],
+        },
+        primaryType: 'Acknowledgment',
+        domain: {
+            name: 'Polymath',
+            chainId: 1,
+            verifyingContract: stAddress
+        },
+        message: {
+            text: 'I acknowledge that freezing Issuance is a permanent and irrevocable change',
+        },
+    };
+    const result = await new Promise((resolve, reject) => { 
+        web3.currentProvider.send(
+            {
+                method: 'eth_signTypedData',
+                params: [from, typedData]
+            },
+            (err, result) => {
+                if (err) {
+                    return reject(err);
+                }
+                resolve(result.result);
+            }
+        );
+    });
+    // console.log('signed by', from);
+    // const recovered = sigUtil.recoverTypedSignature({
+    //     data: typedData,
+    //     sig: result 
+    // })
+    // console.log('recovered address', recovered);
+    return result;
+}
+
+async function getDisableControllerAck(stAddress, from) {
+    const typedData = {
+        types: {
+            EIP712Domain: [
+                { name: 'name', type: 'string' },
+                { name: 'chainId', type: 'uint256' },
+                { name: 'verifyingContract', type: 'address' }
+            ],
+            Acknowledgment: [
+                { name: 'text', type: 'string' }
+            ],
+        },
+        primaryType: 'Acknowledgment',
+        domain: {
+            name: 'Polymath',
+            chainId: 1,
+            verifyingContract: stAddress
+        },
+        message: {
+            text: 'I acknowledge that disabling controller is a permanent and irrevocable change',
+        },
+    };
+    const result = await new Promise((resolve, reject) => { 
+        web3.currentProvider.send(
+            {
+                method: 'eth_signTypedData',
+                params: [from, typedData]
+            },
+            (err, result) => {
+                if (err) {
+                    return reject(err);
+                }
+                resolve(result.result);
+            }
+        );
+    });
+    return result;
+}
+
 function getSignGTMData(tmAddress, investorAddress, fromTime, toTime, expiryTime, validFrom, validTo, nonce, pk) {
     let hash = web3.utils.soliditySha3({
         t: 'address',
@@ -109,5 +194,7 @@ module.exports = {
     getSignSTMData,
     getSignGTMData,
     getSignGTMTransferData,
-    getMultiSignGTMData
+    getMultiSignGTMData,
+    getFreezeIssuanceAck,
+    getDisableControllerAck
 };