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<openssl_pkey_deriveopenssl_pkey_export_to_file>
^OpenSSL FunctionsLast updated: Mon, 26 Oct 2026

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

function openssl_pkey_export(
    #[\SensitiveParameter] OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $key,
    string &$output,
    #[\SensitiveParameter] ?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.

<openssl_pkey_deriveopenssl_pkey_export_to_file>
^OpenSSL FunctionsLast updated: Mon, 26 Oct 2026