PHP Manual: openssl_public

function openssl_public_decrypt(
    string $data,
    #[\SensitiveParameter] string &$decrypted_data,
    OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $public_key,
    int $padding = OPENSSL_PKCS1_PADDING
): bool

openssl_public_decrypt() decrypts data that was previous encrypted via openssl_private_encrypt() and stores the result into decrypted_data.

You can use this function e.g. to check if the message was written by the owner of the private key.

data
decrypted_data
public_key: public_key must be the public key that corresponds to the private key that was used to encrypt the data.
padding: padding can be one of OPENSSL_PKCS1_PADDING, OPENSSL_NO_PADDING.

Returns true on success or false on failure.

Version	Description
8.0.0	`public_key` accepts an OpenSSLAsymmetricKey or OpenSSLCertificate instance now; previously, a resource of type `OpenSSL key` or `OpenSSL X.509` was accepted.

openssl_public_decrypt