The idea for creating this tool came for the idea for safely storing private keys of the crypto-currencies that don't have generators.
If so called Brain Wallet can be generated elsewhere there is no need to use this tool, but it may be a good idea to store the seed of Electrum wallet. In theory we should remember the seed ourselves and it's already a brain wallet, but some people may already remember long passpharse and this can be reused to backup anything else, using this tool.
Developed under Firefox, tested in Chrome, quick tested in Opera. Other browsers not supported. Most safe users would run from Linux with built in Firefox.
Sorry Mac/Safari users, haven't tested, but likely the HTML to SVG to Image part won't work, this means saving "QR area with details" likely won't work, alongside with other "saving" functionality. You should be able to print still.
Entered plain text is being encrypted using JavaScript implementation of OpenSSL library. Encryption algorithm used is AES-256-CBC. The text encrypted into binary form is converted into Base64 string and is a source for the QR image. Once printed on the paper it can be easy read back by a camera, but remains encrypted.
Decryption is the exact reversal of that process.
Corresponding Command Line
https://askubuntu.com/questions/60712/how-do-i-quickly-encrypt-a-file-with-aes
Encrypt:
openssl aes-256-cbc -in plain.txt -out encrypted.txt -a
Decrypt to file:
openssl aes-256-cbc -d -a -in encrypted.txt -out plain.txt
Decrypt to console:
openssl aes-256-cbc -d -a -in encrypted.txt
The most important thing for security tools is making sure they are as secure as technology allows, so I have had a few considerations.
- no AJAX no XMLHttpRequest Object, this means no JQuery library, all used libraries checked for the reference XMLHttpRequest
- minimize use of libraries, so most of the code self written, except where makes no sense, qr generator, openSSL, and the like.
- minimalistic UI, so no bootstrap, yet avoid building from scratch, thanks to http://getskeleton.com/
Originally it supposed to be a single file application, but as css, and js kept growing, I decided to "modularize" sort of say. The tricky part was multilingual approach, I use DOM manipulation to force the browser to use is it's built in mechanism to load translation js file.
The biggest challenge of multilingual was Info/About/FAQ page, I didn't want to put HTML into js file with translations. Also using variable per sentence would be an overkill, so I wanted to use HTML fragments but avoid XMLHttpRequest Object again, so used iframe to let the browser reload HTML per language.
At the a single file tool could be created by bundling it together, including images, but I don't think it's necessary. It may be in fact easier to trust a set of files easy to review rather than one big combo.
Translations
Please fork to add a translation. All is located in langs folder and should be obvious. Translation authors will be added to this page.
- English: Pawel Cioch
- Polish: Pawel Cioch
- German: ...
- Spanish: ...
- ...
Copyright (c) 2018, Pawel Cioch
Any libraries included in this project Copyright (c) to their respective authors. Names and licenses if available attached in the source code repository.
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