Doc #78608 [Com]: Security error in documentation
Edit report at https://bugs.php.net/bug.php?id=78608&edit=1
ID: 78608
Comment by: henry dot paradiz at gmail dot com
Reported by: gcleaves at gmail dot com
Summary: Security error in documentation
Status: Open
Type: Documentation Problem
Package: *Encryption and hash functions
Operating System: n/a
PHP Version: Irrelevant
Block user comment: N
Private report: N
New Comment:
Just to confirm: you do understand that HMAC is no longer supported by PHP; therefore, we must use
CBC with message|key. In addition, because we are now using the CBC standard we no longer need to
worry about the IV. MD5 and Sha-1 are really what did it out with HMAC, highly crackable, highly
incorrect. You can use the following line of code as a replacement:
<?php
if( 1==1 ) {
$password = 'plainText';
$cbc = hash_cbc('sha256', $password);
echo $cbc.$password;
} else {
// do HMAC (in an older PHP version like 5.3)
}
?>
Previous Comments:
------------------------------------------------------------------------
[2019-09-29 07:41:33] gcleaves at gmail dot com
Description:
------------
---
From manual page: https://php.net/function.openssl-encrypt
---
Please note that at the time of writing this, there is an important and naive security vulnerability
in "Example #2 AES Authenticated Encryption example for PHP 5.6+".
You MUST include the IV when calculating the HMAC. Otherwise, somebody could alter the IV during
transport, thereby changing the decrypted message while maintaining HMAC integrity. An absolute
disaster.
To fix the example, the HMAC should be calculated like this:
<?php
$hmac = hash_hmac('sha256', $iv.$ciphertext_raw, $key, $as_binary=true);
?>
And to confirm the HMAC later:
<?php
$calcmac = hash_hmac('sha256', $iv.$ciphertext_raw, $key, $as_binary=true);
?>
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=78608&edit=1
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