From a3603b9098a932534e082829c939706871e69e66 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nicol=C3=A1s=20Venturo?= Date: Fri, 6 Sep 2019 16:02:09 -0300 Subject: [PATCH] Remove SignatureBouncer contract (cherry picked from commit c876254457fcfff717cd79b6122d5dfa228d348f) --- contracts/drafts/SignatureBouncer.sol | 125 -------------------------- 1 file changed, 125 deletions(-) delete mode 100644 contracts/drafts/SignatureBouncer.sol diff --git a/contracts/drafts/SignatureBouncer.sol b/contracts/drafts/SignatureBouncer.sol deleted file mode 100644 index 239a79248..000000000 --- a/contracts/drafts/SignatureBouncer.sol +++ /dev/null @@ -1,125 +0,0 @@ -pragma solidity ^0.5.0; - -import "../GSN/Context.sol"; -import "../access/roles/SignerRole.sol"; -import "../cryptography/ECDSA.sol"; - -/** - * @title SignatureBouncer - * @author PhABC, Shrugs and aflesher - * @dev SignatureBouncer allows users to submit a signature as a permission to - * do an action. - * If the signature is from one of the authorized signer addresses, the - * signature is valid. - * Note that SignatureBouncer offers no protection against replay attacks, users - * must add this themselves! - * - * Signer addresses can be individual servers signing grants or different - * users within a decentralized club that have permission to invite other - * members. This technique is useful for whitelists and airdrops; instead of - * putting all valid addresses on-chain, simply sign a grant of the form - * keccak256(abi.encodePacked(`:contractAddress` + `:granteeAddress`)) using a - * valid signer address. - * Then restrict access to your crowdsale/whitelist/airdrop using the - * `onlyValidSignature` modifier (or implement your own using _isValidSignature). - * In addition to `onlyValidSignature`, `onlyValidSignatureAndMethod` and - * `onlyValidSignatureAndData` can be used to restrict access to only a given - * method or a given method with given parameters respectively. - * See the tests in SignatureBouncer.test.js for specific usage examples. - * - * @notice A method that uses the `onlyValidSignatureAndData` modifier must make - * the _signature parameter the "last" parameter. You cannot sign a message that - * has its own signature in it so the last 128 bytes of msg.data (which - * represents the length of the _signature data and the _signature data itself) - * is ignored when validating. Also non fixed sized parameters make constructing - * the data in the signature much more complex. - * See https://ethereum.stackexchange.com/a/50616 for more details. - */ -contract SignatureBouncer is Context, SignerRole { - using ECDSA for bytes32; - - // Function selectors are 4 bytes long, as documented in - // https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector - uint256 private constant _METHOD_ID_SIZE = 4; - // Signature size is 65 bytes (tightly packed v + r + s), but gets padded to 96 bytes - uint256 private constant _SIGNATURE_SIZE = 96; - - constructor () internal { - // solhint-disable-previous-line no-empty-blocks - } - - /** - * @dev Requires that a valid signature of a signer was provided. - */ - modifier onlyValidSignature(bytes memory signature) { - require(_isValidSignature(_msgSender(), signature), "SignatureBouncer: invalid signature for caller"); - _; - } - - /** - * @dev Requires that a valid signature with a specified method of a signer was provided. - */ - modifier onlyValidSignatureAndMethod(bytes memory signature) { - // solhint-disable-next-line max-line-length - require(_isValidSignatureAndMethod(_msgSender(), signature), "SignatureBouncer: invalid signature for caller and method"); - _; - } - - /** - * @dev Requires that a valid signature with a specified method and params of a signer was provided. - */ - modifier onlyValidSignatureAndData(bytes memory signature) { - // solhint-disable-next-line max-line-length - require(_isValidSignatureAndData(_msgSender(), signature), "SignatureBouncer: invalid signature for caller and data"); - _; - } - - /** - * @dev is the signature of `this + account` from a signer? - * @return bool - */ - function _isValidSignature(address account, bytes memory signature) internal view returns (bool) { - return _isValidDataHash(keccak256(abi.encodePacked(address(this), account)), signature); - } - - /** - * @dev is the signature of `this + account + methodId` from a signer? - * @return bool - */ - function _isValidSignatureAndMethod(address account, bytes memory signature) internal view returns (bool) { - bytes memory msgData = _msgData(); - bytes memory data = new bytes(_METHOD_ID_SIZE); - for (uint256 i = 0; i < data.length; i++) { - data[i] = msgData[i]; - } - return _isValidDataHash(keccak256(abi.encodePacked(address(this), account, data)), signature); - } - - /** - * @dev is the signature of `this + account + methodId + params(s)` from a signer? - * @notice the signature parameter of the method being validated must be the "last" parameter - * @return bool - */ - function _isValidSignatureAndData(address account, bytes memory signature) internal view returns (bool) { - bytes memory msgData = _msgData(); - require(msgData.length > _SIGNATURE_SIZE, "SignatureBouncer: data is too short"); - - bytes memory data = new bytes(msgData.length - _SIGNATURE_SIZE); - for (uint256 i = 0; i < data.length; i++) { - data[i] = msgData[i]; - } - - return _isValidDataHash(keccak256(abi.encodePacked(address(this), account, data)), signature); - } - - /** - * @dev Internal function to convert a hash to an eth signed message - * and then recover the signature and check it against the signer role. - * @return bool - */ - function _isValidDataHash(bytes32 hash, bytes memory signature) internal view returns (bool) { - address signer = hash.toEthSignedMessageHash().recover(signature); - - return signer != address(0) && isSigner(signer); - } -}