RSA

RSA PKCS#1 v1.5 signature verification implementation according to https://datatracker.ietf.org/doc/html/rfc8017[RFC8017]. This library supports PKCS#1 v1.5 padding to avoid malleability via chosen plaintext attacks in practical implementations. The padding follows the EMSA-PKCS1-v1_5-ENCODE encoding definition as per section 9.2 of the RFC. This padding makes RSA semantically secure for signing messages. Inspired by https://github.com/adria0/SolRsaVerify/blob/79c6182cabb9102ea69d4a2e996816091d5f1cd1[Adrià Massanet's work] (GNU General Public License v3.0). Available since v5.1.

Functions

pkcs1Sha256

Same as pkcs1Sha256 but using SHA256 to calculate the digest of data.

function pkcs1Sha256(bytes memory data, bytes memory s, bytes memory e, bytes memory n) internal view returns (bool);

pkcs1Sha256

Verifies a PKCSv1.5 signature given a digest according to the verification method described in https://datatracker.ietf.org/doc/html/rfc8017#section-8.2.2[section 8.2.2 of RFC8017] with support for explicit or implicit NULL parameters in the DigestInfo (no other optional parameters are supported). IMPORTANT: For security reason, this function requires the signature and modulus to have a length of at least 2048 bits. If you use a smaller key, consider replacing it with a larger, more secure, one. WARNING: This verification algorithm doesn't prevent replayability. If called multiple times with the same digest, public key and (valid signature), it will return true every time. Consider including an onchain nonce or unique identifier in the message to prevent replay attacks. WARNING: This verification algorithm supports any exponent. NIST recommends using 65537 (or higher). That is the default value many libraries use, such as OpenSSL. Developers may choose to reject public keys using a low exponent out of security concerns.

function pkcs1Sha256(bytes32 digest, bytes memory s, bytes memory e, bytes memory n) internal view returns (bool);

Parameters

_unsafeReadBytes32

Reads a bytes32 from a bytes array without bounds checking.

function _unsafeReadBytes32(bytes memory array, uint256 offset) private pure returns (bytes32 result);