decrypt using cryptojs not working

Question

I m trying to send a encrypted data via json to client and decrypt it in client using cryptojs

My ROR code

def getkey

  aes = OpenSSL::Cipher::Cipher.new('AES-128-CBC') 
  aes.encrypt
  key = aes.random_key

  session[:key] = key

  render :json => {:mkey => Base64.encode64(key).gsub(/\n/, '')}
end

def getdata
    js = "SOME DATA"

    aes = OpenSSL::Cipher::Cipher.new('AES-128-CBC')
    aes.encrypt
    aes.key = session[:key]
    encrypted = aes.update(js) + aes.final

    encrypted = Base64.encode64(encrypted).gsub(/\n/, '')

    render :json => {:data => encrypted}
end

My Javascript code

var key = btoa(BASE64_ENCODED_KEY);
$http({method: 'GET', url: '/appi/getdata/', params: {SOME_PARAMS}})
.success(function(data, status, headers, config) {
  var dat = btoa(data.data);
  var decrypted = CryptoJS.AES.decrypt(dat, key);
  console.log(decrypted.toString(CryptoJS.enc.Utf8));
});

Getting javascript error "Error: Malformed UTF-8 data." in chrome

Below is a url for simplified jsfiddle for above query

http://jsfiddle.net/7DRdK/1/

Solution

Thanks owlstead, I already figured that out it last couple of days.

I raised this query in crypto-js thread, the problem was I was not specifying IV in crypto-js decryption, as in Ruby if you dont specify any IV it adds \0 as IV.

Below is working code

var encrypted = {};
encrypted.ciphertext = CryptoJS.enc.Base64.parse(data.data);

var decrypted = CryptoJS.AES.decrypt(encrypted, CryptoJS.enc.Base64.parse(BASE64_ENCODED_KEY),
          { iv: CryptoJS.enc.Hex.parse('00000000000000000000000000000000') });;
console.log(decrypted.toString(CryptoJS.enc.Utf8));

This worked for me, this solution was provided to me yesterday by Jeff.Mott.OR (current cryptojs lead dev)

Comments

[Amit Kumar]

decrypted.toString(CryptoJS.enc.Utf8) works for me. I was using decrypted.toString(). Anyway thanks....

[Catmandu]

@sudesh it seems to be a problem..Think CryptoJs cant encrypt JSON objects..Can u please help me..I am getting the same issue

[Catmandu]

@sudesh where should i post it ..its quite large..can u come in chat

[Catmandu]

var data = angular.fromJson(strData); var encrypted = {}; encrypted.ciphertext = CryptoJS.enc.Base64.parse(data.data); var decrypted = CryptoJS.AES.decrypt(encrypted, CryptoJS.enc.Base64.parse(pki),{ iv: CryptoJS.enc.Base64.parse(data.pki) }); var mainData = decrypted.toString(CryptoJS.enc.Utf8); return angular.fromJson(mainData); }].concat($http.defaults.transformResponse), params: default_params, headers: headers }).success(function (data) { var endApi = new Date(); callback(data); });

[Catmandu]

@Sudesh Can you please guide me with this..Am stuck for a long time now

[Sudesh]

@PeeVee after seeing the code you posted, it is same script I coded for a website, seems your bosses know me.. I m just a call away

[Catmandu]

@Sudesh Thanks for the reply..We got to know the issue and have worked on the solution..The issue was chrome specific as the page was reloading as one of the image path specified was not proper. Actually I am not aware that this was the same code you worked on..Have you worked on the whole application