Crypto module is not working with latest node 7.10

Question

The following code snippet is working in Node 0.12.18 (replace Buffer.from to new Buffer) but it's not working with the latest Node version (7.10.0)

Can anybody explain me why this is happening?? Anything is missing in below code.

/* Node.js */
var crypto = require('crypto');

var algorithm = 'aes-256-ctr';

var data  = "Dhanet-Kalan-Chittorgarh"
var encryption_key = "VHUz1dxrhsowwEYGqUnPcE4wvAyz7Vmb";

var encryption_data = _encrypt()

console.log('data for encryption :: ' + data);
console.log('encrypted data :: ' + encryption_data);
console.log('decrypted data :: ' + _decrypt(encryption_data));

function _decrypt(_encryption_data){

    var decipher, dec, chunks, itr_str;

    // remove itr string
    itr_str = _encryption_data.substring(_encryption_data.length-24);
    _encryption_data = _encryption_data.substring(0, _encryption_data.length-24);

    decipher = crypto.createDecipheriv(algorithm, encryption_key, Buffer.from(itr_str, "base64"));
    chunks = []
    chunks.push( decipher.update( Buffer.from(_encryption_data, "base64").toString("binary")) );
    chunks.push( decipher.final('binary') );
    dec = chunks.join("");
    dec = Buffer.from(dec, "binary").toString("utf-8");

    return dec;
}


function _encrypt(){

    //random alpha-numeric string
    var itr_str = Buffer.from(randomString(16)).toString('base64') ; // "3V5eo6XrkTtDFMz2QrF3og==";

    var cipher = crypto.createCipheriv(algorithm, encryption_key, Buffer.from(itr_str, "base64"));
    var chunks = [];
    chunks.push(cipher.update( Buffer.from(data), 'utf8', 'base64'));
    chunks.push(cipher.final('base64'));

    var crypted = chunks.join('');
    crypted = crypted.concat(itr_str);

    return crypted;
}

function randomString(len, an)
{
    an = an&&an.toLowerCase();
    var str="", i=0, min=an=="a"?10:0, max=an=="n"?10:62;
    for(;i++<len;){
        var r = Math.random()*(max-min)+min <<0;
        str += String.fromCharCode(r+=r>9?r<36?55:61:48);
    }
    return str;
}

Answer 1

Node.js v6 introduced some backward-incompatible changes to crypto which are causing this.

I've documented the exact reason in this answer, but because that question is related to hashing I'm reluctant to close your question as a duplicate.

The fix is similar, though (you need to pass binary as encoding for decipher.update(), otherwise it will default to utf-8):

chunks.push( decipher.update( Buffer.from(_encryption_data, "base64"), 'binary') );