CODEWITHSUNDEEP
node.js
Uyi Ehondor
Uyi Ehondor

Reputation: 101

Decrypt cipher text using NodeJs createDecipheriv. What am I doing wrong?

I have the following code that should decrypt an encrypted text:

var crypto = require('crypto');
var Buffer = require('buffer').Buffer;

var iv = new Buffer('the-iv', 'binary'); //length=16
var key = new Buffer('the-secret-key', 'binary');//length=30

var encryptedText = new Buffer('base64-encoded-encrypted-data', 'base64');

var decipher = crypto.createDecipheriv('aes-128-cbc', key, iv); //using the aes-128-cbc algorithm
decrypted = decipher.update(encryptedText, "binary", 'utf8');
decrypted += decipher.final('utf8');

When I execute the script node test-main.js, I get the following error:

node-crypto : Invalid key length 30

crypto.js:355
  this._binding.initiv(cipher, toBuf(key), toBuf(iv));
                ^
Error: DecipherInitIv error
    at new Decipheriv (crypto.js:355:17)
    at Object.Decipheriv (crypto.js:352:12)
    at Object.<anonymous> (path/to/file/test-main.js:9:19)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:901:3

My NodeJs version is 0.10.15

I am not sure what I am doing wrong/missing.

Upvotes: 5

Views: 12078

Answers (2)

Aks Agrawal
Aks Agrawal

Reputation: 1

    var crypto = require('crypto');// dont forget to include this line i am just unable to put this in the code
    var data = JSON.stringify({someKey: "someValue"});

    console.log('Original cleartext: ' + data);
    var algorithm = 'aes-128-ecb';
    var key = 'myVeryTopSecretK';
    var clearEncoding = 'buffer';
    var cipherEncoding = 'base64';

    var cipher = crypto.createCipheriv(algorithm, key, new Buffer(""));

    var cipherChunks = [];
    cipherChunks.push(cipher.update(new Buffer(JSON.stringify({someKey: "someValue"}), 'utf8'), clearEncoding, cipherEncoding));
    cipherChunks.push(cipher.final(cipherEncoding));
    console.log(cipherEncoding + ' ciphertext: ' + cipherChunks.join(''));
    var decipher = crypto.createDecipheriv(algorithm, key, new Buffer(""));
    var plainChunks = [];
    for (var i = 0;i < cipherChunks.length;i++) {
      plainChunks.push(decipher.update(cipherChunks[i], cipherEncoding, clearEncoding));

    }
    plainChunks.push(decipher.final(clearEncoding));
    console.log("UTF8 plaintext deciphered: " + plainChunks.join(''));
//// dont forget to include this line i am just unable to put this in the code
var crypto = require('crypto');

Upvotes: 0

Chandu
Chandu

Reputation: 4561

Please try using a key length of 16. aes-128-cbc uses a 128 bit key.

Upvotes: 15

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