PHP Manual: openssl_private

function openssl_private_decrypt(
    string $data,
    #[\SensitiveParameter] string &$decrypted_data,
    #[\SensitiveParameter] OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $private_key,
    int $padding = OPENSSL_PKCS1_PADDING,
    ?string $digest_algo = null
): bool

openssl_private_decrypt() decrypts data that was previously encrypted via openssl_public_encrypt() and stores the result into decrypted_data.

You can use this function e.g. to decrypt data which is supposed to only be available to you.

data
decrypted_data
private_key: private_key must be the private key that corresponds to the public key that was used to encrypt the data.
padding: padding can be one of OPENSSL_PKCS1_PADDING, OPENSSL_SSLV23_PADDING, OPENSSL_PKCS1_OAEP_PADDING, OPENSSL_NO_PADDING.
digest_algo: The digest algorithm for OAEP padding, or null to use the default algorithm.

Returns true on success or false on failure.

Version	Description
8.5.0	The optional parameter `digest_algo` has been added.
8.0.0	`private_key` accepts an OpenSSLAsymmetricKey or OpenSSLCertificate instance now; previously, a resource of type `OpenSSL key` or `OpenSSL X.509` was accepted.

openssl_private_decrypt