ConFoo 2025

openssl_pkey_new

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

openssl_pkey_newGera uma nova chave privada

Descrição

openssl_pkey_new(?array $options = null): OpenSSLAsymmetricKey|false

openssl_pkey_new() gera uma nova chave privada. Como obter o componente público da chave é mostrado no exemplo abaixo.

Nota: É preciso ter um arquivo openssl.cnf válido instalado para que esta função funcione corretamente. Consulte as notas na seção de instalação para obter mais informações.

Parâmetros

options

Pode ser feito ajuste fino na geração de chaves (como especificar o número de bits) usando options. Consulte openssl_csr_new() para obter mais informações sobre options.

Valor Retornado

Retorna uma instância de OpenSSLAsymmetricKey para a chave privada em caso de sucesso ou false em caso de erro.

Registro de Alterações

Versão Descrição
8.0.0 Em caso de sucesso, esta função retorna uma instância OpenSSLAsymmetricKey agora; anteriormente, retornava um resource do tipo OpenSSL key.
7.1.0 A chave curve_name do parâmetro options foi adicionada para tornar possível a criação de chaves EC com base nos algoritmos de Curva Elíptica.

Exemplos

Exemplo #1 Obtendo a chave pública de uma chave privada

<?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);

?>

O exemplo acima produzirá algo semelhante a:

// Saída anterior ao PHP 8.0.0; observe que a função retorna um recurso
-----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)

// Saída a partir do PHP 8.0.0; observe que a função retorna um objeto
-----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) {
}
adicione uma nota

Notas Enviadas por Usuários (em inglês) 7 notes

up
50
dirt at awoms dot com
11 years ago
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;
up
18
gomez dot alejandre at gmail dot com
6 years ago
Not forget the $configArgs for windows users :D, or the method throws a error with the primary key

//write your configurations :D
$configargs = array(
"config" => "C:/xampp/php/extras/openssl/openssl.cnf",
'private_key_bits'=> 2048,
'default_md' => "sha256",
);

// Create the keypair
$res=openssl_pkey_new($configargs);
// Get private key
openssl_pkey_export($res, $privKey,NULL,$configargs);

and it's for all methods ._ .

a full implementation example here.

https://gist.github.com/DuckHunter213/269a0efd17e709f7f1f177ae7da46ad1

this error take me 3 full days you'r welcome :)
up
13
scott at brynen dot com
9 years ago
If you try and generate a new key using openssl_pkey_new(), and need to specify the size of the key, the key MUST be type-bound to integer

// works
$keysize = 1024;
$ssl = openssl_pkey_new (array('private_key_bits' => $keysize));

// fails
$keysize = "1024";
$ssl = openssl_pkey_new (array('private_key_bits' => $keysize));

// works (force to int)
$keysize = "1024";
$ssl = openssl_pkey_new (array('private_key_bits' => (int)$keysize));
up
3
Andrew
3 years ago
It's not documented here but you can also create ECC keys from existing key parameters (e.g. from JWK):

<?php
$key
= openssl_pkey_new([
'ec' => [
'curve_name' => 'prime256v1',
'x' => $someXValue,
'y' => $someYValue,
'd' => $someDValue
]
]);
?>

You can just provide x/y if it's a public key, or you can just provide d if it's a private key.
up
5
Brad
16 years ago
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"];
?>
up
0
Jan
5 years ago
In case this function returns false, then check your openssl.cnf and make sure that in the [req] section of this file the entry default_bits is not commented out.
up
-1
dodginess at yahoo dot com
7 years ago
If you're using openssl_pkey_new() in conjunction with openssl_csr_new() and want to change the CSR digest algorithm as well as specify a custom key size, the configuration override should be defined once and sent to both functions:

<?php
$config
= array(
'digest_alg' => 'sha1',
'private_key_bits' => 2048,
'private_key_type' => OPENSSL_KEYTYPE_RSA,
);

$privkey = openssl_pkey_new($config);

$csr = openssl_csr_new($dn, $privkey, $config);
?>

Although openssl_pkey_new() will accept the 'digest_alg' argument it won't use it, and setting the value has no effect unless you also set this value for openssl_csr_new(). The reason for this is that the $config array is acting as a drop-in replacement for the values found in the openssl.cnf file, so it must contain all of the override values that you need even if the function they're being sent to won't use them.

Also, if you change the 'digest_alg' to something like 'sha256' and still get an MD5 signed CSR check your openssl.cnf file to see whether the digest algorithm you want to use is actually supported.
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