OPENSSL_SIGN(3) 1 OPENSSL_SIGN(3)
openssl_sign - Generate signature
SYNOPSIS
bool openssl_sign (string $data, string &$signature, mixed $priv_key_id, [mixed $signature_alg = OPENSSL_ALGO_SHA1])
DESCRIPTION
openssl_sign(3) computes a signature for the specified $data by generating a cryptographic digital signature using the private key associ-
ated with $priv_key_id. Note that the data itself is not encrypted.
PARAMETERS
o $data
- The string of data you wish to sign
o $signature
- If the call was successful the signature is returned in $signature.
o $priv_key_id
- resource - a key, returned by openssl_get_privatekey(3) string - a PEM formatted key
o $signature_alg
- int - one of these Signature Algorithms. string - a valid string returned by openssl_get_md_methods(3) example,
"sha256WithRSAEncryption" or "sha384".
RETURN VALUES
Returns TRUE on success or FALSE on failure.
EXAMPLES
Example #1
openssl_sign(3) example
<?php
// $data is assumed to contain the data to be signed
// fetch private key from file and ready it
$pkeyid = openssl_pkey_get_private("file://src/openssl-0.9.6/demos/sign/key.pem");
// compute signature
openssl_sign($data, $signature, $pkeyid);
// free the key from memory
openssl_free_key($pkeyid);
?>
Example #2
openssl_sign(3) example
<?php
//data you want to sign
$data = 'my data';
//create new private and public key
$new_key_pair = openssl_pkey_new(array(
"private_key_bits" => 2048,
"private_key_type" => OPENSSL_KEYTYPE_RSA,
));
openssl_pkey_export($new_key_pair, $private_key_pem);
$details = openssl_pkey_get_details($new_key_pair);
$public_key_pem = $details['key'];
//create signature
openssl_sign($data, $signature, $private_key_pem, OPENSSL_ALGO_SHA256);
//save for later
file_put_contents('private_key.pem', $private_key_pem);
file_put_contents('public_key.pem', $public_key_pem);
file_put_contents('signature.dat', $signature);
//verify signature
$r = openssl_verify($data, $signature, $public_key_pem, "sha256WithRSAEncryption");
var_dump($r);
?>
SEE ALSO
openssl_verify(3).
PHP Documentation Group OPENSSL_SIGN(3)