AES 256bit File encrypt in sandbox. This software uses PNaCL. Encrypt mode is CBC. Key is derive by PBKDF2. It is convenient to transfer in internet. Because you can recommend this software for sandbox. PNaCL ToraTora can't access local disk on your PC. So You can be used safely.
All PNaCL chrome apps without permission can accsess files by http.
All PNaCL chrome apps without permission send input password.(maybe)
So I think you must not use unreliable encrypt software of PNaCL chrome apps.
Google Chrome 49(Windows/Mac OS X/Linux/ChromeOS)
FreeBSD or Linux without PNaCL, You can use JSToraTora.
PNaCL is Portable Version of Native Client developed by Google. Native Client is program code that run on virtual pc created by Browser. Important thing,this virtual pc is sandbox. And therefore,we can run program code which is downloaded in internet, safely.
PNaCL ToraTora is PNaCL Version of ToraTora. Original ToraTora is here. You can download English version. But document is all japanese.
Original ToraTora can encrypt by smartcard. And you can encrypt by smartcard without smartcard. Because you can use USB flash drives as smartcard. This is enabled by myuToken.
Install from Chrome Web Store
How to use
Please see here.
Openssl : 4-clause BSD license & Apache License Version 1.0
You can encrypt by AES+. AES+ is special AES.
Even if damaged by the use of PNaCL ToraTora, it does not take any responsibility.