openssl_seal
(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
openssl_seal — Seal (encrypt) data
Description
string
$data,string
&$sealed_data,array
&$encrypted_keys,array
$public_key,string
$cipher_algo,string
&$iv = null): int|false
openssl_seal() seals (encrypts)
data by using the given cipher_algo with a randomly generated
secret key. The key is encrypted with each of the public keys
associated with the identifiers in public_key
and each encrypted key is returned
in encrypted_keys. This means that one can send
sealed data to multiple recipients (provided one has obtained their
public keys). Each recipient must receive both the sealed data and
the envelope key that was encrypted with the recipient's public key.
Parameters
-
data -
The data to seal.
-
sealed_data -
The sealed data.
-
encrypted_keys -
Array of encrypted keys.
-
public_key -
Array of OpenSSLAsymmetricKey instances containing public keys.
-
cipher_algo -
The cipher method.
CautionThe default value (
'RC4') is considered insecure. It is strongly recommended to explicitly specify a secure cipher method. -
iv -
The initialization vector.
Return Values
Returns the length of the sealed data on success, or false on error.
If successful the sealed data is returned in
sealed_data, and the envelope keys in
encrypted_keys.
Changelog
| Version | Description |
|---|---|
| 8.0.0 |
public_key accepts an array of
OpenSSLAsymmetricKey instances now;
previously, an array of resources of type OpenSSL key
was accepted.
|
| 8.0.0 |
cipher_algo is no longer an optional parameter.
|
| 8.0.0 |
iv is nullable now.
|
Examples
Example #1 openssl_seal() example
<?php
// $data is assumed to contain the data to be sealed
// fetch public keys for our recipients, and ready them
$fp = fopen("/src/openssl-0.9.6/demos/maurice/cert.pem", "r");
$cert = fread($fp, 8192);
fclose($fp);
$pk1 = openssl_get_publickey($cert);
// Repeat for second recipient
$fp = fopen("/src/openssl-0.9.6/demos/sign/cert.pem", "r");
$cert = fread($fp, 8192);
fclose($fp);
$pk2 = openssl_get_publickey($cert);
// seal message, only owners of $pk1 and $pk2 can decrypt $sealed with keys
// $ekeys[0] and $ekeys[1] respectively.
openssl_seal($data, $sealed, $ekeys, array($pk1, $pk2));
// free the keys from memory
openssl_free_key($pk1);
openssl_free_key($pk2);
?>
