@defuse

I came across your library in some of those slim threads and thought it might be great to use, as I've currently been investigating encryption libraries to finish my security module.

That said, two things I noticed immediately:

1. It lacks composer support
2. It takes over the exception handler (I understand this is for security)

I'd like to fix these two problems and make use of your library, but based on the previous composer.json pull request that is open, I'd like to verify that you're interested first.

With respect to the exception handler, it would make more sense, if the exception handler was changed temporarily during the processes which could throw exceptions. Your exception handler could be split to a separate class, and http://php.net/manual/en/function.restore-exception-handler.php can be used to restore the previous one once decrypting is done (for example).

Add a function for deriving a key from a password with PBKDF2.

We have to think really hard about how to make this usable, since we want to make sure they're doing the salt right (by making it hard to do it wrong).

At the moment i try to fix an issue on my server:

Cipher method not supported. This is normally caused by an outdated version of OpenSSL (and/or OpenSSL compiled for FIPS compliance). Please upgrade to a newer version of OpenSSL that supports aes-256-ctr to use this library.

After some searching i found two constants in the Core class: CIPHER_METHOD and LEGACY_CIPHER_METHOD. Is it possible to set the cipher method from outside without manipulating the original code? Did not find any possibility to do so.

I'm using php7.2 on different OS (Ubuntu, Alpine Linux and Windows 10) with v2.2.1 of the defuse/php-encryption package, and LibreSSL 2.7.4

I sign the git tags, but we need GPG signatures that people actually know how to verify. For now, I'll use my email address key, and then we'll switch to my air-gapped key in the future once I get it set up correctly.

If there is a better place to ask questions regarding this library please let me know. When I attempt to save the randomly generated key using Key::saveToAsciiSafeString Intellij alerts me that "Non-static method 'saveToAsciiSafeString should not be called statically"

Can someone please provide proper syntax or ideally an example of how to create a random key one time then store in a format that can be saved as a variable so that I can call that to decrypt stored data in the future. I understand that this may not be the safest of all possible scenarios but aside from storing a key generated with this library I am left with mcrypt. Thanks!

This library uses all static methods, and while some of them make sense, its really too bad that the library's Crypto class can't be used as an injectable instance. Currently, testing services that make use of this library means running expensive crypto hashing algorithms that slow down a unit testing feedback loop.

Switching to non-statics would also allow for certain configurations to be used, if certain aspects needed to be overrided (I know, likely not suggested), for example providing a different hash function but defaulting to the current constant sha256.

Thank you for this great library and for considering this issue.

The PBKDF2 polyfill in Core.php (which should run only for PHP 5.4 users) doesn't pre-hash the password before PBKDF2 inner loop if the password's length is greater than the underlying hash algorithm's output length.

This could lead to DoS situation if a malicious user is able to input long passwords to the PBKDF2 function. I.e. on my machine, 100000 byte password and 25000 iterations (with SHA256 and 32 byte output) took ~16 seconds.

I suggest we add a conditional pre-hash step before the outer PBKDF2 loop to mitigate this issue: check the password lenght, and if it is greater than $hash_length, do a pre-hash.

Roughly something like:

if (Core::ourStrlen($password) > $hash_length) {
    $password = \hash($algorithm, $password, true);
}

In all the pull requests I'm seeing comments I left to review some of scott's commits... so the thing people are basing their work off of must be newer than our current v2.0 branch and I'm very confused.

Maybe we should write a paper, similar to the NaCl paper, about our API. We found a way to make file encryption usable so I think it's worth it. It would document our design choices and perhaps make a good argument for libsodium to support the same API for encrypting/decrypting files.

Look over all the code, check for:

• Unreachable code (e.g. functions that are never called).
• Files without trailing new lines.
• Tabs that should be spaces.
• Consistent capitalization (e.g. some static methods are CamelCase some are whateverThisIsCalled)
• Comments are correct (and all the methods that need documentation have doc comments).

I am not using SSL is this required? I am using windows 10, PHPv7,fast cgi. I am runing the example.php and this is the report.

HTML Error: Cannot safely perform encryption

Exception: Defuse\Crypto\Exception\CannotPerformOperationException Object ( [message:protected] => [string:Exception:private] => [code:protected] => 0 [file:protected] => php-encryption-master\src\Crypto.php [line:protected] => 618 [trace:Exception:private] => Array ( [0] => Array ( [file] => php-encryption-master\src\Crypto.php [line] => 221 [function] => ensureFunctionExists [class] => Defuse\Crypto\Crypto [type] => :: [args] => Array ( [0] => openssl_get_cipher_methods ) ) [1] => Array ( [file] => php-encryption-master\src\Crypto.php [line] => 65 [function] => runtimeTest [class] => Defuse\Crypto\Crypto [type] => :: [args] => Array ( ) ) [2] => Array ( [file] => php-encryption-master\example.php [line] => 9 [function] => createNewRandomKey [class] => Defuse\Crypto\Crypto [type] => :: [args] => Array ( ) ) ) [previous:Exception:private] => ) Notice: Undefined variable: key in php-encryption-master\example.php on line 20

Now that the fix is in place for the PHP8 - is it possible to get a new release published so that we can grab it from composer? Right now the latest release is from April 2021. Thanks

Hi, I'm trying to use the userPassword scenario and I found confusion when the user change the password after the initial key was saved. is there any suggestion for unlocking the saved key when the user changes the password? is there any method to update the key and decrypt saved encrypted data?

What are the recommendations in choosing a password for Crypto::encryptWithPassword(), which will eliminate the expediency of brute force when compromising an encrypted file? Suppose the password consists of a set of printed characters of ASCII. What will be the safe minimum length?

The change password method breaks the process, even with a try catch block, but creating random password and unlocking are fine.

$a = KeyProtectedByPassword::loadFromAsciiSafeString($userdata['protectedKey']); //ok $a->changePassword( $password, $_REQUEST['newPassword'] ); echo $a->saveToAsciiSafeString(); //fail

However unlocking is fine ... $a = KeyProtectedByPassword::loadFromAsciiSafeString($userdata['protectedKey']); //ok $a->unlockKey($_REQUEST['oldPassword']); //ok echo $a->saveToAsciiSafeString(); //ok