node-bury
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A cryptographic and steganographic image library for nodejs.
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#Bury
A cryptographic and steganographic image library for nodejs.
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A nodejs port of [BuriedUnderTheNoiseFloor](https://github.com/jspark311/BuriedUnderTheNoiseFloor).
Write up is at my [blog](http://www.joshianlindsay.com/index.php?id=126).
If anyone is feeling generous, my bitcoin address is *17da1aqXEhdqMkbEq66nc2n5DeAnrnNbsK*. Donations help me justify spending time on my computer to my wife. :-)
Comments and issues posted on github will be answered. Pull-requests are always welcome if you've fixed or enhanced something.
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### Installation
git clone https://github.com/jspark311/node-bury.git
cd node-bury
npm install bury
### Usage
##### Encrypting
var Bury = require('bury');
var options = {
enableRed: true,
enableGreen: true,
enableBlue: true,
visibleResult: false,
rescaleCarrier: true
};
var test_image = new Bury('./test_carrier.jpg', 'saddroPs', options);
var msg = 'This is a silly test message that the NSA will spend millions of dollars to unearth.'
test_image.setMessage(msg);
test_image.outputImage('./test_carrier.png');
##### Decrypting
var Bury = require('bury');
var test_readback = new Bury('./test_carrier.png', 'saddroPs');
console.log(test_readback.getMessage());
##### Testing passwords for mutual compatibility
var Bury = require('bury');
// testPasswordCompatibility() returns 'true' if the provided passwords are mutually compatible.
// 'false' otherwise. The function requires at least two passwords. Maximum of three, because we
// can only have (at maximum) three independent channels.
console.log('Are these passwords compatible? ' +
Bury.testPasswordCompatibility('key_for_steg-img.php', 'key_for_form.php'));
console.log('Are these passwords compatible? ' +
Bury.testPasswordCompatibility('one-of-thess-passwords', 'is-not-mutally', 'compatible'));
### Compatibility note
The carriers produced by this code will not inter-operate with those produced with the PHP version, and vice-versa. The *only* reason for this is that the default PRNG in PHP was able to be seeded, and the one in node is not. This might not be a problem, as I at least had enough foresight to bake a version field into the header in the original. So I have incremented this value for the JS code.
This problem may be resolvable by changing the PHP code to use the same mersenne twister algorithm used here. But I doubt that this is going to cause anyone enough grief to care.
Just sayin'...
### TODO
* Compression is broken at the moment.
* File-embedding is untested.
* The control-flow that this code inherited from the PHP original feels awful in JS. There are too many synchronous operations and arbitrary branching. Need to impart a more functional style to it.
* There is presently no enforcement of "one instance, one operation". Risks obtuse crypto bugs caused by crufty IVs and seeded RNGs from prior operations.
* It would be nice to be able to automatically write output files if such-and-such an option parameter is passed in at instantiation. The same goes for encrypting.
* Decrypting can (in principle) be done automatically. With nothing more than the carrier and a password, a header can be discovered and the data retrieved. But, at present, you must make a separate function call.
* Write unit tests. Should be easy to do, since the criteria for success is unambiguous.
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License is MIT, so be free.
---J. Ian Lindsay