{
    "Function": "permit",
    "File": "contracts/cgp/ERC20Permit.sol",
    "Parent Contracts": [
        "contracts/cgp/ERC20.sol",
        "contracts/cgp/interfaces/IERC20Permit.sol",
        "contracts/cgp/interfaces/IERC20.sol"
    ],
    "High-Level Calls": [],
    "Internal Calls": [
        "revert PermitExpired()",
        "_approve",
        "keccak256(bytes)",
        "keccak256(bytes)",
        "abi.encodePacked()",
        "revert InvalidV()",
        "revert InvalidSignature()",
        "revert InvalidS()",
        "abi.encode()",
        "ecrecover(bytes32,uint8,bytes32,bytes32)"
    ],
    "Library Calls": [],
    "Low-Level Calls": [],
    "Code": "function permit(\n        address issuer,\n        address spender,\n        uint256 value,\n        uint256 deadline,\n        uint8 v,\n        bytes32 r,\n        bytes32 s\n    ) external {\n        if (block.timestamp > deadline) revert PermitExpired();\n\n        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) revert InvalidS();\n\n        if (v != 27 && v != 28) revert InvalidV();\n\n        bytes32 digest = keccak256(\n            abi.encodePacked(\n                EIP191_PREFIX_FOR_EIP712_STRUCTURED_DATA,\n                DOMAIN_SEPARATOR,\n                keccak256(abi.encode(PERMIT_SIGNATURE_HASH, issuer, spender, value, nonces[issuer]++, deadline))\n            )\n        );\n\n        address recoveredAddress = ecrecover(digest, v, r, s);\n\n        if (recoveredAddress != issuer) revert InvalidSignature();\n\n        // _approve will revert if issuer is address(0x0)\n        _approve(issuer, spender, value);\n    }"
}