openssl_sign

(PHP 4 >= 4.0.4, PHP 5)

openssl_sign -- Generate signature

Description

bool openssl_sign ( string data, string &signature, mixed priv_key_id [, int signature_alg] )

Returns TRUE on success or FALSE on failure. If successful the signature is returned in signature.

openssl_sign() computes a signature for the specified data by using SHA1 for hashing followed by encryption using the private key associated with priv_key_id. Note that the data itself is not encrypted.

Note: Optional 4th parameter signature_alg was added in version 5.0.0. Its default value is OPENSSL_ALGO_SHA1. For more information see the list of Signature Algorithms.

Example 1. openssl_sign() example

<?php
// $data is assumed to contain the data to be signed

// fetch private key from file and ready it
$fp fopen("/src/openssl-0.9.6/demos/sign/key.pem""r");
$priv_key fread($fp8192);
fclose($fp);
$pkeyid openssl_get_privatekey($priv_key);

// compute signature
openssl_sign($data$signature$pkeyid);

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

See also openssl_verify().