PHP Manual
OpenSSL Functions
Gets an exportable representation of a key into a string

openssl_pkey_export

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

openssl_pkey_export — Gets an exportable representation of a key into a string

Description

openssl_pkey_export(
    OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $key,
    string &$output,
    ?string $passphrase = null,
    ?array $options = null
): bool

openssl_pkey_export() exports key as a PEM encoded string and stores it into output (which is passed by reference).

Note: You need to have a valid openssl.cnf installed for this function to operate correctly. See the notes under the installation section for more information.

Parameters

key
output
passphrase: The key is optionally protected by passphrase.
options: options can be used to fine-tune the export process by specifying and/or overriding options for the openssl configuration file. See openssl_csr_new() for more information about options.

Return Values

Returns true on success or false on failure.

Changelog

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