(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 key of the options parameter was
added to make it possible to create EC keys based on Elliptic Curve algorithms.
|
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, PHP_EOL;
$public_key = openssl_pkey_get_public($public_key_pem);
var_dump($public_key);
?>The above example will output something similar to:
// Output prior to PHP 8.0.0; note, the function returns a resource
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwknBFEherZe74BiRjTFA
hqwZ1SK7brwq7C/afnLXKhRR7jnrpfM0ypC46q8xz5UZswenZakJ7kd5fls+r4Bv
3P8XsKYLTh2m1GiWQhV1g77cNIN4qNWh70PiDO3fB2446o1LBgToQYuRZS5YQRfJ
rVD0ysgtVcCU9tjaey28HlgApOpYFTaaKPj2MBmEYpMC+kG2HhL12GfpHUi2eiXI
dXT2WskWHWvUrmQ7fJIfI92JlDokV62DH/q1oiedLs9OPNb0rL1aAmYdzaVN6XNH
x/o4Lh125v2vAPV9E3fZCDc/HDEUaahpjanMiCQEgEDp5Hr+CRkvERT5/ydN+p08
5wIDAQAB
-----END PUBLIC KEY-----
resource(6) of type (OpenSSL key)
// Output as of PHP 8.0.0; note, the function returns an object
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwknBFEherZe74BiRjTFA
hqwZ1SK7brwq7C/afnLXKhRR7jnrpfM0ypC46q8xz5UZswenZakJ7kd5fls+r4Bv
3P8XsKYLTh2m1GiWQhV1g77cNIN4qNWh70PiDO3fB2446o1LBgToQYuRZS5YQRfJ
rVD0ysgtVcCU9tjaey28HlgApOpYFTaaKPj2MBmEYpMC+kG2HhL12GfpHUi2eiXI
dXT2WskWHWvUrmQ7fJIfI92JlDokV62DH/q1oiedLs9OPNb0rL1aAmYdzaVN6XNH
x/o4Lh125v2vAPV9E3fZCDc/HDEUaahpjanMiCQEgEDp5Hr+CRkvERT5/ydN+p08
5wIDAQAB
-----END PUBLIC KEY-----
object(OpenSSLAsymmetricKey)#2 (0) {
}