Simple way to encrypt and decrypt files in php
<?php
/*
Online PHP Examples with Source Code
website: http://4evertutorials.blogspot.in/
*/
function CryptFile($InFileName,$OutFileName,$password){
//check the file if exists
if (file_exists($InFileName)){
//get file content as string
$InFile = file_get_contents($InFileName);
// get string length
$StrLen = strlen($InFile);
// get string char by char
for ($i = 0; $i < $StrLen ; $i++){
//current char
$chr = substr($InFile,$i,1);
//get password char by char
$modulus = $i % strlen($password);
$passwordchr = substr($password,$modulus, 1);
//encryption algorithm
$OutFile .= chr(ord($chr)+ord($passwordchr));
}
$OutFile = base64_encode($OutFile);
//write to a new file
if($newfile = fopen($OutFileName, "c")){
file_put_contents($OutFileName,$OutFile);
fclose($newfile);
return true;
}else{
return false;
}
}else{
return false;
}
}
function DecryptFile($InFileName,$OutFileName,$password){
//check the file if exists
if (file_exists($InFileName)){
//get file content as string
$InFile = file_get_contents($InFileName);
$InFile = base64_decode($InFile);
// get string length
$StrLen = strlen($InFile);
// get string char by char
for ($i = 0; $i < $StrLen ; $i++){
//current char
$chr = substr($InFile,$i,1);
//get password char by char
$modulus = $i % strlen($password);
$passwordchr = substr($password,$modulus, 1);
//encryption algorithm
$OutFile .= chr(ord($chr)-ord($passwordchr));
}
//write to a new file
if($newfile = fopen($OutFileName, "c")){
file_put_contents($OutFileName,$OutFile);
fclose($newfile);
return true;
}else{
return false;
}
}else{
return false;
}
}
//Example
$orginalfile = 'orginal.jpg';
$crypt = 'crypt.jpg';
$decrypt = 'decrypt.jpg';
$password = 'pass';
CryptFile($orginalfile,$crypt,$password);
DecryptFile($crypt,$decrypt,$password);
?>
