dexorder

2024-10-17 02:42:28 -04:00
commit 25def69c66
878 changed files with 112489 additions and 0 deletions
--- a/lib_openzeppelin_contracts/contracts/token/ERC20/extensions/ERC20Permit.sol
+++ b/lib_openzeppelin_contracts/contracts/token/ERC20/extensions/ERC20Permit.sol
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/ERC20Permit.sol)
+
+pragma solidity ^0.8.20;
+
+import {IERC20Permit} from "./IERC20Permit.sol";
+import {ERC20} from "../ERC20.sol";
+import {ECDSA} from "../../../utils/cryptography/ECDSA.sol";
+import {EIP712} from "../../../utils/cryptography/EIP712.sol";
+import {Nonces} from "../../../utils/Nonces.sol";
+
+/**
+ * @dev Implementation of the ERC-20 Permit extension allowing approvals to be made via signatures, as defined in
+ * https://eips.ethereum.org/EIPS/eip-2612[ERC-2612].
+ *
+ * Adds the {permit} method, which can be used to change an account's ERC-20 allowance (see {IERC20-allowance}) by
+ * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
+ * need to send a transaction, and thus is not required to hold Ether at all.
+ */
+abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712, Nonces {
+    bytes32 private constant PERMIT_TYPEHASH =
+        keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
+
+    /**
+     * @dev Permit deadline has expired.
+     */
+    error ERC2612ExpiredSignature(uint256 deadline);
+
+    /**
+     * @dev Mismatched signature.
+     */
+    error ERC2612InvalidSigner(address signer, address owner);
+
+    /**
+     * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
+     *
+     * It's a good idea to use the same `name` that is defined as the ERC-20 token name.
+     */
+    constructor(string memory name) EIP712(name, "1") {}
+
+    /**
+     * @inheritdoc IERC20Permit
+     */
+    function permit(
+        address owner,
+        address spender,
+        uint256 value,
+        uint256 deadline,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) public virtual {
+        if (block.timestamp > deadline) {
+            revert ERC2612ExpiredSignature(deadline);
+        }
+
+        bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline));
+
+        bytes32 hash = _hashTypedDataV4(structHash);
+
+        address signer = ECDSA.recover(hash, v, r, s);
+        if (signer != owner) {
+            revert ERC2612InvalidSigner(signer, owner);
+        }
+
+        _approve(owner, spender, value);
+    }
+
+    /**
+     * @inheritdoc IERC20Permit
+     */
+    function nonces(address owner) public view virtual override(IERC20Permit, Nonces) returns (uint256) {
+        return super.nonces(owner);
+    }
+
+    /**
+     * @inheritdoc IERC20Permit
+     */
+    // solhint-disable-next-line func-name-mixedcase
+    function DOMAIN_SEPARATOR() external view virtual returns (bytes32) {
+        return _domainSeparatorV4();
+    }
+}