openssl_error_string(3) [php man page]

OPENSSL_ERROR_STRING(3) 						 1						   OPENSSL_ERROR_STRING(3)

openssl_error_string - Return openSSL error message

SYNOPSIS

       string openssl_error_string (void  )

DESCRIPTION

       openssl_error_string(3)	returns the last error from the openSSL library. Error messages are queued, so this function should be called mul-
       tiple times to collect all of the information. The last error will be the most recent one.

RETURN VALUES

	Returns an error message string, or FALSE if there are no more error messages to return.

EXAMPLES

       Example #1

	      openssl_error_string(3) example

	      <?php
	      // lets assume you just called an openssl function that failed
	      while ($msg = openssl_error_string())
		  echo $msg . "<br />
";
	      ?>

PHP Documentation Group 												   OPENSSL_ERROR_STRING(3)

OPENSSL_VERIFY(3)							 1							 OPENSSL_VERIFY(3)

openssl_verify - Verify signature

SYNOPSIS

       int openssl_verify (string  $data, string  $signature, mixed  $pub_key_id, [mixed  $signature_alg = OPENSSL_ALGO_SHA1])

DESCRIPTION

       openssl_verify(3)  verifies  that  the $signature is correct for the specified $data using the public key associated with $pub_key_id. This
       must be the public key corresponding to the private key used for signing.

PARAMETERS

	      o $data
		- The string of data used to generate the signature previously

	      o $signature
		- A raw binary string, generated by openssl_sign(3) or similar means

	      o $pub_key_id
		- resource - a key, returned by openssl_get_publickey(3) string - a  PEM  formatted  key,  example,  "-----BEGIN  PUBLIC  KEY-----
		MIIBCgK..."

	      o $signature_alg
		- int - one of these Signature Algorithms.  string - a valid string returned by openssl_get_md_methods(3) example, "sha1WithRSAEn-
		cryption" or "sha512".

RETURN VALUES

	Returns 1 if the signature is correct, 0 if it is incorrect, and -1 on error.

CHANGELOG

       +--------+------------------------------------------+
       |Version |					   |
       |	|					   |
       |	|		Description		   |
       |	|					   |
       +--------+------------------------------------------+
       | 5.2.0	|					   |
       |	|					   |
       |	|  The $signature_alg parameter was added. |
       |	|					   |
       +--------+------------------------------------------+
EXAMPLES

       Example #1

	      openssl_verify(3) example

	      <?php
	      // $data and $signature are assumed to contain the data and the signature

	      // fetch public key from certificate and ready it
	      $pubkeyid = openssl_pkey_get_public("file://src/openssl-0.9.6/demos/sign/cert.pem");

	      // state whether signature is okay or not
	      $ok = openssl_verify($data, $signature, $pubkeyid);
	      if ($ok == 1) {
		  echo "good";
	      } elseif ($ok == 0) {
		  echo "bad";
	      } else {
		  echo "ugly, error checking signature";
	      }
	      // free the key from memory
	      openssl_free_key($pubkeyid);
	      ?>

       Example #2

	      openssl_verify(3) example

	      <?php
	      //data you want to sign
	      $data = 'my data';

	      //create new private and public key
	      $private_key_res = openssl_pkey_new(array(
		  "private_key_bits" => 2048,
		  "private_key_type" => OPENSSL_KEYTYPE_RSA,
	      ));
	      $details = openssl_pkey_get_details($private_key_res);
	      $public_key_res = openssl_pkey_get_public($details['key']);

	      //create signature
	      openssl_sign($data, $signature, $private_key_res, "sha1WithRSAEncryption");

	      //verify signature
	      $ok = openssl_verify($data, $signature, $public_key_res, OPENSSL_ALGO_SHA1);
	      if ($ok == 1) {
		  echo "valid";
	      } elseif ($ok == 0) {
		  echo "invalid";
	      } else {
		  echo "error: ".openssl_error_string();
	      }
	      ?>

SEE ALSO

       openssl_sign(3).

PHP Documentation Group 													 OPENSSL_VERIFY(3)