{
    "Function": "tryRecover",
    "File": "contracts/lib/openzeppelin-contracts/contracts/utils/cryptography/ECDSA.sol",
    "Parent Contracts": [],
    "High-Level Calls": [],
    "Internal Calls": [
        "ecrecover(bytes32,uint8,bytes32,bytes32)"
    ],
    "Library Calls": [],
    "Low-Level Calls": [],
    "Code": "function tryRecover(\n        bytes32 hash,\n        uint8 v,\n        bytes32 r,\n        bytes32 s\n    ) internal pure returns (address, RecoverError) {\n        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature\n        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines\n        // the valid range for s in (301): 0 < s < secp256k1n \u00f7 2 + 1, and for v in (302): v \u2208 {27, 28}. Most\n        // signatures from current libraries generate a unique signature with an s-value in the lower half order.\n        //\n        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value\n        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or\n        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept\n        // these malleable signatures as well.\n        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {\n            return (address(0), RecoverError.InvalidSignatureS);\n        }\n        if (v != 27 && v != 28) {\n            return (address(0), RecoverError.InvalidSignatureV);\n        }\n\n        // If the signature is valid (and not malleable), return the signer address\n        address signer = ecrecover(hash, v, r, s);\n        if (signer == address(0)) {\n            return (address(0), RecoverError.InvalidSignature);\n        }\n\n        return (signer, RecoverError.NoError);\n    }"
}