update ECDSA version to fix a sig malleability issue

see also: OpenZeppelin/openzeppelin-contracts#3610
and: code-423n4/2023-07-nounsdao-findings#198

packages/nouns-contracts/contracts/external/openzeppelin/ECDSA.sol

@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v4.9.0) (utils/cryptography/ECDSA.sol)
+
+pragma solidity ^0.8.0;
+
+import { Strings } from '@openzeppelin/contracts/utils/Strings.sol';
+
+/**
+ * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
+ *
+ * These functions can be used to verify that a message was signed by the holder
+ * of the private keys of a given address.
+ */
+library ECDSA {
+    enum RecoverError {
+        NoError,
+        InvalidSignature,
+        InvalidSignatureLength,
+        InvalidSignatureS,
+        InvalidSignatureV // Deprecated in v4.8
+    }
+
+    function _throwError(RecoverError error) private pure {
+        if (error == RecoverError.NoError) {
+            return; // no error: do nothing
+        } else if (error == RecoverError.InvalidSignature) {
+            revert('ECDSA: invalid signature');
+        } else if (error == RecoverError.InvalidSignatureLength) {
+            revert('ECDSA: invalid signature length');
+        } else if (error == RecoverError.InvalidSignatureS) {
+            revert("ECDSA: invalid signature 's' value");
+        }
+    }
+
+    /**
+     * @dev Returns the address that signed a hashed message (`hash`) with
+     * `signature` or error string. This address can then be used for verification purposes.
+     *
+     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
+     * this function rejects them by requiring the `s` value to be in the lower
+     * half order, and the `v` value to be either 27 or 28.
+     *
+     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
+     * verification to be secure: it is possible to craft signatures that
+     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
+     * this is by receiving a hash of the original message (which may otherwise
+     * be too long), and then calling {toEthSignedMessageHash} on it.
+     *
+     * Documentation for signature generation:
+     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
+     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
+     *
+     * _Available since v4.3._
+     */
+    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
+        if (signature.length == 65) {
+            bytes32 r;
+            bytes32 s;
+            uint8 v;
+            // ecrecover takes the signature parameters, and the only way to get them
+            // currently is to use assembly.
+            /// @solidity memory-safe-assembly
+            assembly {
+                r := mload(add(signature, 0x20))
+                s := mload(add(signature, 0x40))
+                v := byte(0, mload(add(signature, 0x60)))
+            }
+            return tryRecover(hash, v, r, s);
+        } else {
+            return (address(0), RecoverError.InvalidSignatureLength);
+        }
+    }
+
+    /**
+     * @dev Returns the address that signed a hashed message (`hash`) with
+     * `signature`. This address can then be used for verification purposes.
+     *
+     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
+     * this function rejects them by requiring the `s` value to be in the lower
+     * half order, and the `v` value to be either 27 or 28.
+     *
+     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
+     * verification to be secure: it is possible to craft signatures that
+     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
+     * this is by receiving a hash of the original message (which may otherwise
+     * be too long), and then calling {toEthSignedMessageHash} on it.
+     */
+    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
+        (address recovered, RecoverError error) = tryRecover(hash, signature);
+        _throwError(error);
+        return recovered;
+    }
+
+    /**
+     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
+     *
+     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
+     *
+     * _Available since v4.3._
+     */
+    function tryRecover(
+        bytes32 hash,
+        bytes32 r,
+        bytes32 vs
+    ) internal pure returns (address, RecoverError) {
+        bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
+        uint8 v = uint8((uint256(vs) >> 255) + 27);
+        return tryRecover(hash, v, r, s);
+    }
+
+    /**
+     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
+     *
+     * _Available since v4.2._
+     */
+    function recover(
+        bytes32 hash,
+        bytes32 r,
+        bytes32 vs
+    ) internal pure returns (address) {
+        (address recovered, RecoverError error) = tryRecover(hash, r, vs);
+        _throwError(error);
+        return recovered;
+    }
+
+    /**
+     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
+     * `r` and `s` signature fields separately.
+     *
+     * _Available since v4.3._
+     */
+    function tryRecover(
+        bytes32 hash,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) internal pure returns (address, RecoverError) {
+        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
+        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
+        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
+        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
+        //
+        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
+        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
+        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
+        // these malleable signatures as well.
+        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
+            return (address(0), RecoverError.InvalidSignatureS);
+        }
+
+        // If the signature is valid (and not malleable), return the signer address
+        address signer = ecrecover(hash, v, r, s);
+        if (signer == address(0)) {
+            return (address(0), RecoverError.InvalidSignature);
+        }
+
+        return (signer, RecoverError.NoError);
+    }
+
+    /**
+     * @dev Overload of {ECDSA-recover} that receives the `v`,
+     * `r` and `s` signature fields separately.
+     */
+    function recover(
+        bytes32 hash,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) internal pure returns (address) {
+        (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
+        _throwError(error);
+        return recovered;
+    }
+
+    /**
+     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
+     * produces hash corresponding to the one signed with the
+     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
+     * JSON-RPC method as part of EIP-191.
+     *
+     * See {recover}.
+     */
+    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32 message) {
+        // 32 is the length in bytes of hash,
+        // enforced by the type signature above
+        /// @solidity memory-safe-assembly
+        assembly {
+            mstore(0x00, '\x19Ethereum Signed Message:\n32')
+            mstore(0x1c, hash)
+            message := keccak256(0x00, 0x3c)
+        }
+    }
+
+    /**
+     * @dev Returns an Ethereum Signed Message, created from `s`. This
+     * produces hash corresponding to the one signed with the
+     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
+     * JSON-RPC method as part of EIP-191.
+     *
+     * See {recover}.
+     */
+    function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
+        return keccak256(abi.encodePacked('\x19Ethereum Signed Message:\n', Strings.toString(s.length), s));
+    }
+
+    /**
+     * @dev Returns an Ethereum Signed Typed Data, created from a
+     * `domainSeparator` and a `structHash`. This produces hash corresponding
+     * to the one signed with the
+     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
+     * JSON-RPC method as part of EIP-712.
+     *
+     * See {recover}.
+     */
+    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32 data) {
+        /// @solidity memory-safe-assembly
+        assembly {
+            let ptr := mload(0x40)
+            mstore(ptr, '\x19\x01')
+            mstore(add(ptr, 0x02), domainSeparator)
+            mstore(add(ptr, 0x22), structHash)
+            data := keccak256(ptr, 0x42)
+        }
+    }
+
+    /**
+     * @dev Returns an Ethereum Signed Data with intended validator, created from a
+     * `validator` and `data` according to the version 0 of EIP-191.
+     *
+     * See {recover}.
+     */
+    function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
+        return keccak256(abi.encodePacked('\x19\x00', validator, data));
+    }
+}

packages/nouns-contracts/contracts/external/openzeppelin/SignatureChecker.sol

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v4.9.0) (utils/cryptography/SignatureChecker.sol)
+
+pragma solidity ^0.8.0;
+
+import './ECDSA.sol';
+import '@openzeppelin/contracts/interfaces/IERC1271.sol';
+
+/**
+ * @dev Signature verification helper that can be used instead of `ECDSA.recover` to seamlessly support both ECDSA
+ * signatures from externally owned accounts (EOAs) as well as ERC1271 signatures from smart contract wallets like
+ * Argent and Gnosis Safe.
+ *
+ * _Available since v4.1._
+ */
+library SignatureChecker {
+    /**
+     * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
+     * signature is validated against that smart contract using ERC1271, otherwise it's validated using `ECDSA.recover`.
+     *
+     * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
+     * change through time. It could return true at block N and false at block N+1 (or the opposite).
+     */
+    function isValidSignatureNow(
+        address signer,
+        bytes32 hash,
+        bytes memory signature
+    ) internal view returns (bool) {
+        (address recovered, ECDSA.RecoverError error) = ECDSA.tryRecover(hash, signature);
+        return
+            (error == ECDSA.RecoverError.NoError && recovered == signer) ||
+            isValidERC1271SignatureNow(signer, hash, signature);
+    }
+
+    /**
+     * @dev Checks if a signature is valid for a given signer and data hash. The signature is validated
+     * against the signer smart contract using ERC1271.
+     *
+     * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
+     * change through time. It could return true at block N and false at block N+1 (or the opposite).
+     */
+    function isValidERC1271SignatureNow(
+        address signer,
+        bytes32 hash,
+        bytes memory signature
+    ) internal view returns (bool) {
+        (bool success, bytes memory result) = signer.staticcall(
+            abi.encodeWithSelector(IERC1271.isValidSignature.selector, hash, signature)
+        );
+        return (success &&
+            result.length >= 32 &&
+            abi.decode(result, (bytes32)) == bytes32(IERC1271.isValidSignature.selector));
+    }
+}

packages/nouns-contracts/contracts/governance/NounsDAOV3Proposals.sol

@@ -20,8 +20,8 @@ pragma solidity ^0.8.19;
 import './NounsDAOInterfaces.sol';
 import { NounsDAOV3DynamicQuorum } from './NounsDAOV3DynamicQuorum.sol';
 import { NounsDAOV3Fork } from './fork/NounsDAOV3Fork.sol';
-import { SignatureChecker } from '@openzeppelin/contracts/utils/cryptography/SignatureChecker.sol';
-import { ECDSA } from '@openzeppelin/contracts/utils/cryptography/ECDSA.sol';
+import { SignatureChecker } from '../external/openzeppelin/SignatureChecker.sol';
+import { ECDSA } from '../external/openzeppelin/ECDSA.sol';
 import { SafeCast } from '@openzeppelin/contracts/utils/math/SafeCast.sol';
 
 library NounsDAOV3Proposals {