Gravity Forms: encrypt and decrypt entry/fields

hhdev-gf-encrypt-decrypt.php

// Gravity Forms: encrypt and decrypt form field
// runs only on form id 9
// change it to you own form id(x) : gform_save_field_value_x and gform_get_input_value_x
// change it to you own form id(x) and field (y) : gform_save_field_value_x and gform_get_input_value_x_y
// info: https://docs.gravityforms.com/gform_get_input_value/
// info: https://docs.gravityforms.com/gform_save_field_value/
// --------------------------

// add it to wp-config or leave it here...
// add your own key here!
define('HHDEV_GF_ENCRYPTION_KEY','add 48 characters key');

// Encrypt 
// ------------------------

function hhdev_gravityforms_encrypt( $to_encrypt )
{
	if ( '' === $to_encrypt ) return null;

	if ( function_exists('openssl_encrypt') && function_exists('openssl_random_pseudo_bytes') )
	{
		$iv = openssl_random_pseudo_bytes( openssl_cipher_iv_length( 'aes-256-cbc' ) );
		$encrypted = openssl_encrypt( $to_encrypt, 'aes-256-cbc', HHDEV_GF_ENCRYPTION_KEY, 0, $iv );

		return base64_encode( $encrypted . '::' . $iv );
	}

	return base64_encode( $to_encrypt );
} // end hhdev_gravityforms_encrypt


// Decrypt 
// -------------------------

function hhdev_gravityforms_decrypt( $to_decrypt )
{
	if ( '' === $to_decrypt ) return null;

	if ( function_exists('openssl_decrypt') )
	{
		@list( $encrypted_data, $iv ) = explode( '::', base64_decode( $to_decrypt ), 2 );

    	return openssl_decrypt( $encrypted_data, 'aes-256-cbc', HHDEV_GF_ENCRYPTION_KEY, 0, $iv );
    }

    return base64_decode( $to_decrypt );
} 

// gravity forms functions
// --------------------------

/**
 * Encrypt all values for GF entries
**/
add_filter( 'gform_save_field_value_9', 'hhdev_gf_save_field_value', 10, 4 );

function hhdev_gf_save_field_value( $value, $lead, $field, $form )
{
    return hhdev_gravityforms_encrypt( $value );
}


// Always decrypt
// ----------------------------

add_filter( 'gform_get_input_value_9', 'hhdev_gf_decrypt_field', 10, 4 );

function hhdev_gf_decrypt_field( $value, $entry, $field, $input_id )
{
    return hhdev_gravityforms_decrypt( $value );
}