(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
openssl_pkey_new — Generates a new private key
openssl_pkey_new() generates a new private key. How to obtain the public component of the key is shown in an example below.
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.
options
You can finetune the key generation (such as specifying the number of
bits) using options. See
openssl_csr_new() for more information about
options.
Returns an OpenSSLAsymmetricKey instance for the pkey on success, or false on
error.
| Version | Description |
|---|---|
| 8.0.0 |
On success, this function returns an OpenSSLAsymmetricKey instance now;
previously, a resource of type OpenSSL key was returned.
|
| 7.1.0 | The curve_name option was added to make it possible to create EC keys. |
Example #1 Obtain the public key from a private key
<?php
$private_key = openssl_pkey_new();
$public_key_pem = openssl_pkey_get_details($private_key)['key'];
echo $public_key_pem;
$public_key = openssl_pkey_get_public($public_key_pem);
var_dump($public_key);
?>
The above example will output something similar to:
-----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEArZFsmN2P6rx1Xt7YV95o gcdlal0k3ryiIhFNzjwtRNNTXfEfBr6lUuaIJYQ8/XqEBX0hpcfuuF6tTRlonA3t WLME0QFD93YVsAaXcy76YqjjqcRRodIBphAbYyyMI/lXkQAdn7kbAmr7neSOsMYJ El9Wo4Hl4oG6e52ZnYHyqW9dxh4hX93eupR2TmcCdVf+r9xoHewP0KJYSHt7vDUX AQlWYcQiWHIadFsmL0orr6mutlXFReoHbesgKY9/3YLOu0JfxflSjIZ2JeL1NTl1 MsmODsUwgAUrwnWKKx+eQUP5g3GnSB3dPkRh9zRVRiLNWbCugyjrf3e6DgQWrW7j pwIDAQAB -----END PUBLIC KEY----- resource(5) of type (OpenSSL key)