How to decrypt base64 string from NodeJs encrypted?

Questions / Help
1

Hi everyone,

I’m try encrypt message by NodeJs, and convert to base64,
after send to Elixir server with WebSocket,
trying to decrypt from base64 string,
but i never success…

and i’m trying compare both side encrypt result,
it’s have alot different…

here is my testing code…

NodeJs part…

var crypto = require( 'crypto' );
var key = '0000000000000000';
var value = 'test';
var cipher = crypto.createCipher('rc4', key );
var encoded = cipher.update( value, 'utf8', 'base64');
encoded += cipher.final( 'base64' );

console.info( 'Result[' + encoded + ']' );
//Result[sFvlow==]

Elixir part…


key = "0000000000000000"
value = "test"
{ _, r } = :crypto.stream_init(:rc4, key ) |> :crypto.stream_encrypt( value )
result = Base.encode64( r )
IO.puts "Result[#{ result }]"
#Result[/BrV9A==]

anyone can help me, please :slight_smile:

Sorry for my english,
Thanks

2

According to http://rc4.online-domain-tools.com/ using your key and input, it outputs: fc 1a d5 f4

What your javascript code puts out for the encoded value: B0 5B E5 A3

What your Elixir code puts out for the encoded value: FC 1A D5 F4

So it looks like it is correct in Elixir and wrong in your javascript code, thus implying that the code generating it in Javascript is wrong. :slight_smile:

1 Like
3

Oh my god, @OvermindDL1 Thank you Very Very Much :joy:

your advice lead me found the solution,

i use this code …
the both side had correct base64 string.


var crypto = require( 'crypto' );
var key = '0000000000000000';
    key = require( 'crypto-js' ).enc.Utf8.parse( key ); //add this to convert key
var value = 'test';
var cipher = crypto.createCipher('rc4', key );
var encoded = cipher.update( value, 'utf8', 'base64');
encoded += cipher.final( 'base64' );

console.info( 'Result[' + encoded + ']' );
//Result[/BrV9A==]

i don’t really know why about the this,
but problem is resolve,
Thank you so so much :smiley:

1 Like
4

Awesome! Thanks for the follow-up, I honestly had no clue ‘why’ the javascript version was not working so it is awesome to see the working code. :smiley:

1 Like