PHP | openssl_private_encrypt() Function

Hello folks! welcome back to a new edition of our tutorial on PHP. In this tutorial guide, we are going to be studying about the PHP openssl_private_encrypt() Function.

The openssl_private_encrypt() function is used to encrypt the data with private key.

This built-in function encrypts the data and it can be decrypted using the built-in PHP openssl_public_decrypt() function.

syntax

Following below is the syntax to use this function -

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

READ: PHP | openssl_pkey_get_private Function

Parameter Details

Sr.No	Parameter	Description
1	data
2	encrypted	It will have the data that is encrypted.
3	key	The private key.
4	padding	The padding you can apply are : OPENSSL_PKCS1_PADDING, OPENSSL_NO_PADDING.

Return Value

This PHP function returns true on success or false on failure.

PHP Version

This PHP function works from PHP version greater than 5.0.0.

Example1

The following example illustrates the usage of PHP openssl_private_encrypt() function to encrypt data using Private Key -

<?php
   // To encrpt data
   $privkey = openssl_pkey_new();
   openssl_pkey_export_to_file($privkey, 'C:/xampp/htdocs/modules/openssl/privatekey.pem');
   $data = 'Welcome To WebDesignTutorialz';
   openssl_private_encrypt ($data, $crypted , file_get_contents('C:/xampp/htdocs/modules/openssl/privatekey.pem'),OPENSSL_PKCS1_PADDING);	
   echo $crypted;
?>

Output

When the above code is executed, it will produce the following result -

��Z甌�3�g[.zT�J�tn��g�M�P>���7U��k�vJ�@/��ɥ���U�j��ː�RC��bQGQ: �NN����Z��#J0J ��C�t�SC޳���pxol� ����U��'�V7[�
#��{�]�Fa��#�p_��Y��<�xYKƛR> k‹Rs�t��:��.Is*5YP-�]�^��2(t0��!Td}�],HeUP�p��ާև� 9e;��\��h��R

Example2

The following example below illustrates the usage of the openssl_private_encrypt() and the openssl_public_decrypt() functions for encrypting and decrypting data -

<?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 WebDesignTutorialz';
   $isvalid = openssl_private_encrypt ($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" => "NG",
      "stateOrProvinceName" => "Rivers",
      "localityName" => "test1",
      "organizationName" => "test2",
      "organizationalUnitName" => "test3",
      "commonName" => "www.test.com",
      "emailAddress" => "[email protected]"
   );
   $cert = openssl_csr_new($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;
   }
?>

Output

When the above code is executed, it 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 WebDesignTutorialz

READ: PHP | openssl_pkey_export_to_file() Function

Alright guys! This is where we are going to be rounding up for this tutorial post. In our next tutorial, we will be studying about the openssl_public_encrypt() Function.

Feel free to ask your questions where necessary and we will attend to them as soon as possible. If this tutorial was helpful to you, you can use the share button to share this tutorial.

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