(PHP 4 >= 4.2.0, PHP 5)
openssl_pkey_new — Generates a new private key
$configargs
] )openssl_pkey_new() generates a new private and public key pair. The public component of the key can be obtained using openssl_pkey_get_public().
Note: 必须安装有效的 openssl.cnf 以保证此函数正确运行。参考有关安装的说明以获得更多信息。
configargs
You can finetune the key generation (such as specifying the number of
bits) using configargs. See
openssl_csr_new() for more information about
configargs.
Returns a resource identifier for the pkey on success, or FALSE on
error.
dirt at awoms dot com (2013-03-26 20:52:09)
Working example:
$config = array(
"digest_alg" => "sha512",
"private_key_bits" => 4096,
"private_key_type" => OPENSSL_KEYTYPE_RSA,
);
// Create the private and public key
$res = openssl_pkey_new($config);
// Extract the private key from $res to $privKey
openssl_pkey_export($res, $privKey);
// Extract the public key from $res to $pubKey
$pubKey = openssl_pkey_get_details($res);
$pubKey = $pubKey["key"];
$data = 'plaintext data goes here';
// Encrypt the data to $encrypted using the public key
openssl_public_encrypt($data, $encrypted, $pubKey);
// Decrypt the data using the private key and store the results in $decrypted
openssl_private_decrypt($encrypted, $decrypted, $privKey);
echo $decrypted;
zelnaga at gmail dot com (2012-06-07 17:21:16)
Getting the public key corresponding to a particular private key, through the methods provided for by OpenSSL, is a bit cumbersome. An easier way to do it is to use phpseclib, a pure PHP RSA implementation:
<?php
include('Crypt/RSA.php');
$rsa = new Crypt_RSA();
$rsa->loadKey('...');
$privatekey = $rsa->getPrivateKey();
$publickey = $rsa->getPublicKey();
?>
Doesn't require any extensions be installed. It'll use bcmath or gmp if they're available, for speed, but doesn't even require those.
jthijssen at notloxic dot nl (2011-02-11 06:17:53)
If you want to change the default private key size (1024) too something else you can use the following code:
<?php
$config = array('private_key_bits' => 512);
$privKey = openssl_pkey_new($config);
?>
Mind though that the minimum number of bits is 384. Any lower will trigger an error.
Brad (2008-04-02 12:17:50)
It's easier than all that, if you just want the keys:
<?php
// Create the keypair
$res=openssl_pkey_new();
// Get private key
openssl_pkey_export($res, $privkey);
// Get public key
$pubkey=openssl_pkey_get_details($res);
$pubkey=$pubkey["key"];
?>
NOSPAM dot alchaemist at hiperlinux dot com dot ar (2004-05-30 00:17:25)
As you probably found, getting the public key is not as direct as you might think with this documentation.
You can easily get into messages like:
Warning: openssl_pkey_get_public(): Don't know how to get public key from this private key (the documentation lied) in D:\www\keys.php on line 4
The correct steps to get the whole thing seem to be these:
<?
$dn = array("countryName" => 'XX', "stateOrProvinceName" => 'State', "localityName" => 'SomewhereCity', "organizationName" => 'MySelf', "organizationalUnitName" => 'Whatever', "commonName" => 'mySelf', "emailAddress" => 'user@domain.com');
$privkeypass = '1234';
$numberofdays = 365;
$privkey = openssl_pkey_new();
$csr = openssl_csr_new($dn, $privkey);
$sscert = openssl_csr_sign($csr, null, $privkey, $numberofdays);
openssl_x509_export($sscert, $publickey);
openssl_pkey_export($privkey, $privatekey, $privkeypass);
openssl_csr_export($csr, $csrStr);
echo $privatekey; // Will hold the exported PriKey
echo $publickey; // Will hold the exported PubKey
echo $csrStr; // Will hold the exported Certificate
?>
Now all you need to do is to make some research on each individual function.