(PHP 4 = 4.2.0)
openssl_pkey_export_to_file()
saves an ascii-armoured (PEM encoded) rendition of key into the file named by outfilename. The key can be
optionally protected by a
passphrase.
configargs 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 configargs. 成功回傳TRUE失敗回傳FALSE。
注: 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.