best method to encrypt or decrypt in php

Here is a safe encrypt and decrypt function for php developer. You can Encrypt and Decrypt using md5. The md5() function calculates the MD5 hash of a string. md5() and sha1() provides the same functinality of encryption in php but they differ in a simple way that md5() generates 32 characters of encrypted string which sha1() generates same of 40 characters.

<?php
/*
Online PHP Examples with Source Code
website: http://4evertutorials.blogspot.com/
*/


function encrypt_decrypt($action, $string) {
   $output = false;

   $key = 'My strong random secret key';

   // initialization vector 
   $iv = md5(md5($key));

   if( $action == 'encrypt' ) {
       $output = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, $iv);
       $output = base64_encode($output);
   }
   else if( $action == 'decrypt' ){
       $output = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), base64_decode($string), MCRYPT_MODE_CBC, $iv);
       $output = rtrim($output, "");
   }
   return $output;
}

?>

How to use encrypt or decrypt code:
 

<?php
/*
Online PHP Examples with Source Code
website: http://4evertutorials.blogspot.com/
*/


$plain_txt = "This is my plain text";
$encrypted_txt = encrypt_decrypt('encrypt', $plain_txt);
echo "Encrypted = $encrypted_txt\n";
echo "
";
$decrypted_txt = encrypt_decrypt('decrypt', $encrypted_txt);
echo "Decrypted = $decrypted_txt\n";

?>

By: 4evertutorials On 8/20/2014

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Simple method to encrypt and decrypt files in PHP

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);

?>

By: 4evertutorials On 1/23/2013

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