PHP - Function openssl_public_decrypt()

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Definition and Usage

The openssl_public_decrypt() function will decrypt the data with the public key.

Description

Using function openssl_public_decrypt() will decrypt the data that was encrypted using openssl_private_encrypt().

Syntax

openssl_public_decrypt ( string $data , string &$decrypted , mixed $key [, int $padding = OPENSSL_PKCS1_PADDING ] ) : bool

Parameters

Return Values

PHP openssl_public_decrypt() function returns TRUE on success or FALSE on failure.

PHP Version

This function will work from PHP Version greater than 5.0.0.

Example 1

To encrypt data using openssl_private_encrypt() and decrypt using openssl_public_decrypt():

<?php
   // Save Private Key
   $privkey = openssl_pkey_new();
   openssl_pkey_export_to_file($privkey, 'C:/xampp/htdocs/modules/openssl/privatekey.pem');
	
   // To encrpt data
   $data = 'Welcome To TuorialsPoint';
   $isvalid = openssl_private_encrypt ($data, $crypted , file_get_contents('C:/xampp/htdocs/modules/openssl/privatekey.pem'),OPENSSL_PKCS1_PADDING);	
   echo "Data encryption : ".$crypted;
   echo ">br/<>br/<";
	
   //Save Public Key
   $dn = array(
      "countryName" => "IN",
      "stateOrProvinceName" => "Karnataka",
      "localityName" => "test1",
      "organizationName" => "test2",
      "organizationalUnitName" => "test3",
      "commonName" => "www.test.com",
      "emailAddress" => "xyz@test.com"
   );
   $cert = openssl_csr_new($dn, $privkey);
   $cert = openssl_csr_sign($cert, null, $privkey, 365);
   openssl_x509_export_to_file($cert, 'C:/xampp/htdocs/modules/openssl/publickey.pem');
		
   if ($isvalid) {	
      openssl_public_decrypt ($crypted, $decrypted , file_get_contents('C:/xampp/htdocs/modules/openssl/publickey.pem'),OPENSSL_PKCS1_PADDING);	
      echo "Data decryption : ".$decrypted;
   }
?>

This will produce the following result:

Data encryption : k��G��7)xy{�N3Г�x<�J^�gd��Ψ�I?{��<�Ws3�mW$��h��(F;tJ�J�W��|�9L�vL��xF��f��,�(N�ΰ��n���Y%Oo,�2��Qh��G�|-��}���1�6Tm�qS�wb���[�i�-r�F��rQhZ��$�� ��U�pMC��Y�n�0,Z�CuG��8�h��@4f��7ؕ�w��;��d��ʈ��$�I^�Z��at��?�

Data decryption : Welcome To TuorialsPoint

Example 2

To encrypt file content using openssl_private_encrypt() and decrypt using openssl_public_decrypt():

<?php
   // Save Private Key
   $privkey = openssl_pkey_new();
   openssl_pkey_export_to_file($privkey, 'C:/xampp/htdocs/modules/openssl/privatekey.pem');
	
   // To encrpt data
   $data = file_get_contents('C:/xampp/htdocs/modules/openssl/test.txt');
   $isvalid = openssl_private_encrypt ($data, $crypted , file_get_contents('C:/xampp/htdocs/modules/openssl/privatekey.pem'),OPENSSL_PKCS1_PADDING);	
   echo "Data encryption : ".$crypted;
   echo ">br/<>br/<";
	
   //Save Public Key
   $dn = array(
      "countryName" => "IN",
      "stateOrProvinceName" => "Karnataka",
      "localityName" => "test1",
      "organizationName" => "test2",
      "organizationalUnitName" => "test3",
      "commonName" => "www.test.com",
      "emailAddress" => "xyz@test.com"
   );
   $cert = openssl_csr_new($dn, $privkey);
   $cert = openssl_csr_sign($cert, null, $privkey, 365);
   openssl_x509_export_to_file($cert, 'C:/xampp/htdocs/modules/openssl/publickey.pem');
		
   if ($isvalid) {	
      openssl_public_decrypt ($crypted, $decrypted , file_get_contents('C:/xampp/htdocs/modules/openssl/publickey.pem'),OPENSSL_PKCS1_PADDING);	
      echo "Data decryption : ".$decrypted;
   }
?>

This will produce the following result:

Data encryption : ��V*�+@4CҺX�i�mM6� ��,?�F,��+�q ��@��g�N6c<*eh��:��5Z��&�&'+= �
��b��J�r ��aO�@gƝ��m�Gy�4W2�ҋ��%��pX@�k�DW�fEW��$j�>i��~��1���w�m}���}�����5I��x� ��H�*A8�� ��U�7~°��F�}4����DV�MZ��望C �'C��-�7�f�

Data decryption : This is data encryption test using openssl php module.