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kpcrypt/lib.php

80 lines
2.9 KiB
PHP

<?php
/**
* @param string $data The data to be encrypted, this can only encrypt strings.
* @param string $key The key to use to encrypt the data, this key should be generated using the openssl_random_pseudo_bytes
* @param string $cipherMethod The cypher method to use in the encryption process, these can be checked using
* @param bool $integrity_check Check if the encrypted data can also be decypted, this will take 2x more time to process the data, but will make 100% sure that the data is safe and can be decrypted.
*/
function encryptData( string $data, string $key, string $cipherMethod = 'AES-256-CBC', bool $integrity_check = TRUE) {
// Lowercase the cipher
$cipherMethod = strtolower($cipherMethod);
// Check if the encryption method is valid
if (!in_array($cipherMethod, openssl_get_cipher_methods())) {
// Cypher was not in the available ciphers list.
return FALSE;
}
// To encrypt a string
$iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length($cipherMethod));
// Encrypt the data
$encryptedData = openssl_encrypt($data, $cipherMethod, $key, OPENSSL_RAW_DATA, $iv);
// Append the iv to the encrypted data
$encryptedData = $iv . $encryptedData;
// base64 encrypt to make sure we don't lose bytes
$encryptedData = base64_encode($encryptedData);
// Check if we should verify the integrity of the encryption
if ( $integrity_check === TRUE ) {
// Test for decryption validity
if ( md5(decryptData($encryptedData, $key, $cipherMethod)) === md5($data) ) {
// Put the output in the result
return $encryptedData;
} else {
// Assign the output to the result
return FALSE;
}
} else {
// Simply return the results
return $encryptedData;
}
}
/**
* @param string $data The data to be encrypted, this can only encrypt strings.
* @param string $key The key to use to encrypt the data, this key should be generated using the openssl_random_pseudo_bytes
* @param string $cipherMethod The cypher method to use in the encryption process, these can be checked using
*/
function decryptData( string $data, string $key, string $cipherMethod = 'AES-256-CBC' ) {
// Lowercase the cipher
$cipherMethod = strtolower($cipherMethod);
// Check if the encryption method is valid
if (!in_array($cipherMethod, openssl_get_cipher_methods())) {
// Cypher was not in the available ciphers list.
return FALSE;
}
// base64 decode the data.
$data = base64_decode($data);
// Get the length of the IV
$iv_length = openssl_cipher_iv_length($cipherMethod);
// Get the IV from the decoded data
$iv = substr($data,0,$iv_length);
// Get the encrypted string from the data
$data = substr($data, $iv_length);
// Decrypt the data
$data = openssl_decrypt($data,$cipherMethod,$key, OPENSSL_RAW_DATA, $iv);
// Return the data
return $data;
}