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openssl_open

(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

openssl_openOpen sealed data

Description

openssl_open(
    string $data,
    string &$output,
    string $encrypted_key,
    OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $private_key,
    string $cipher_algo,
    ?string $iv = null
): bool

openssl_open() opens (decrypts) data using the private key associated with the key identifier private_key and the envelope key encrypted_key, and fills output with the decrypted data. The envelope key is generated when the data are sealed and can only be used by one specific private key. See openssl_seal() for more information.

Parameters

data

output

If the call is successful the opened data is returned in this parameter.

encrypted_key

private_key

cipher_algo

The cipher method.

Caution

The default value ('RC4') is considered insecure. It is strongly recommended to explicitly specify a secure cipher method.

iv

The initialization vector.

Return Values

Returns true on success or false on failure.

Changelog

Version Description
8.0.0 private_key accepts an OpenSSLAsymmetricKey or OpenSSLCertificate instance now; previously, a resource of type OpenSSL key or OpenSSL X.509 CSR was accepted.
8.0.0 cipher_algo is no longer an optional parameter.

Examples

Example #1 openssl_open() example

<?php
// $sealed and $env_key are assumed to contain the sealed data
// and our envelope key, both given to us by the sealer.

// fetch private key from file and ready it
$fp = fopen("/src/openssl-0.9.6/demos/sign/key.pem", "r");
$priv_key = fread($fp, 8192);
fclose($fp);
$pkeyid = openssl_get_privatekey($priv_key);

// decrypt the data and store it in $open
if (openssl_open($sealed, $open, $env_key, $pkeyid)) {
echo
"here is the opened data: ", $open;
} else {
echo
"failed to open data";
}

// free the private key from memory
openssl_free_key($pkeyid);
?>

See Also

add a note

User Contributed Notes 2 notes

up
1
sdc
12 years ago
PHP compiled without OpenSSL support? Here's how you can call the openssl command-line utility to achieve the same goal:

<?php
// $sealed and $env_key are assumed to contain the sealed data
// and our envelope key, both given to us by the sealer.

// specify private key file and passphrase
$pkey_file='key.pem';
$pkey_pp='netsvc';

// call openssl to decrypt envelope key
$ph=proc_open('openssl rsautl -decrypt -inkey '.
escapeshellarg($pkey_file).' -passin fd:3',array(
0 => array('pipe','r'), // stdin < envelope key
1 => array('pipe','w'), // stdout > decoded envelope key
2 => STDERR,
3 => array('pipe','r'), // < passphrase
),$pipes);
// write envelope key
fwrite($pipes[0],$env_key);
fclose($pipes[0]);
// write private key passphrase
fwrite($pipes[3],$pkey_pp);
fclose($pipes[3]);
// read decoded key, convert to hexadecimal
$env_key='';
while(!
feof($pipes[1])){
$env_key.=sprintf("%02x",ord(fgetc($pipes[1])));
}
fclose($pipes[1]);
if(
$xc=proc_close($ph)){
echo
"Exit code: $xc\n";
}

// call openssl to decryp
$ph=proc_open('openssl rc4 -d -iv 0 -K '.$env_key,array(
0 => array('pipe','r'), // stdin < sealed data
1 => array('pipe','w'), // stdout > opened data
2 => STDERR,
),
$pipes);
// write sealed data
fwrite($pipes[0],$sealed);
fclose($pipes[0]);
// read opened data
//$open=stream_get_contents($pipes[1]);
$open='';
while(!
feof($pipes[1])){
$open.=fgets($pipes[1]);
}
fclose($pipes[1]);
if(
$xc=proc_close($ph)){
echo
"Exit code: $xc\n";
}

// display the decrypted data
echo $open;

?>
up
1
Gareth Owen
15 years ago
Example code, assume mycert.pem is a certificate containing both private and public key.

$cert = file_get_contents("mycert.pem");

$public = openssl_get_publickey($cert);
$private = openssl_get_privatekey($cert);

$data = "I'm a lumberjack and I'm okay.";

echo "Data before: {$data}\n";
openssl_seal($data, $cipher, $e, array($public));

echo "Ciphertext: {$cipher}\n";

openssl_open($cipher, $open, $e[0], $private);
echo "Decrypted: {$open}\n";
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