NodeJS Decrypt des3 Unicode - node.js

Question

I have the following snippet of code
var crypto = require("crypto");
var iv = new Buffer('d146ec4ce3f955cb', "hex");
var key = new Buffer('dc5c3319dc25c1f6f11f6a792a6dd28864c9dd48be26c2e4', "hex");
var encrypted = new Buffer('6A57201D19B07ABFAE74B453BA46381C', "hex");
var cipher = crypto.createDecipheriv('des3', key, iv);
var result = cipher.update(encrypted);
result += cipher.final();
console.log("result: " + result);
The result is "password"
This snippet works great for ASCII based words.
However, I have some unicode passwords.
So for instance this is Pi:
UU__3185CDAA15C1CDED
I have tried using this value, plus the removal of the "UU__" but no gain.
I also tried something like this for the encrypted data:
var encrypted = new Buffer('UU__3185CDAA15C1CDED', "utf16le");
and
var result = cipher.update(encrypted, 'ucs2');
but no go..
I get the following error
Error: error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decr ypt
at Error (native)
at Decipheriv.Cipher.final (crypto.js:202:26)
at Object.<anonymous> (/Users/miker/Local Projects/rec10_decryption/server2.js:14:18)
at Module._compile (module.js:460:26)
at Object.Module._extensions..js (module.js:478:10)
at Module.load (module.js:355:32)
at Function.Module._load (module.js:310:12)
at Function.Module.runMain (module.js:501:10)
at startup (node.js:129:16)
at node.js:814:3
Any assistance would be greatly appreciated.

Answer 1

Dropping the UU_ prefix and using this code works for me:
var crypto = require('crypto');
var iv = new Buffer('d146ec4ce3f955cb', 'hex');
var key = new Buffer('dc5c3319dc25c1f6f11f6a792a6dd28864c9dd48be26c2e4', 'hex');
var encrypted = new Buffer('3185CDAA15C1CDED', 'hex');
var cipher = crypto.createDecipheriv('des3', key, iv);
var result = Buffer.concat([
cipher.update(encrypted),
cipher.final()
]).toString('ucs2');
console.log('result: ' + result);
// outputs: result: Π
When you do result += cipher.final(), it's first converting result from a Buffer to a (utf8) string, and then appending cipher.final() converted from a Buffer to a (utf8) string. When you have multi-byte characters, this can cause data corruption if you have a character's bytes span across calls to .update() and .final(). Keeping them as Buffers, concatenating them as binary, and then converting the final concatenated result to a utf16 string will work and is much safer.