openssl_private_decrypt() decrypts data that was previous encrypted via openssl_private_encrypt() and stores the result into decrypted. key must be the private key corresponding that was used to encrypt the data. padding defaults to OPENSSL_PKCS1_PADDING, but can also be one of OPENSSL_SSLV23_PADDING, OPENSSL_PKCS1_OAEP_PADDING OPENSSL_NO_PADDING.