nodejs crypto module vs crypto-js

Question

I'm quite new to NodeJs and trying to figure out how to use the "crypto" module. While playing around with it I notice the difference between the "crypto" module in NodeJs and crypto-js:

With crypto-js, I have:

function SHA256Hash(password, salt, iteration) {
    var saltedpassword = salt + password;
    var sha256 = CryptoJS.algo.SHA256.create();
    for(var i = 0; i < iteration; i++) {
            alert("saltedpassword = " + saltedpassword);
            sha256.update(saltedpassword);
            var saltedpassword = sha256.finalize();
            sha256.reset();
    }       
    return saltedpassword.toString(CryptoJS.enc.Base64);
}

Then call :

var hashedPassword = SHA256Hash("123456789", "ASIN", 3)

And receive :

saltedpassword = ASIN123456789
saltedpassword = 3362d80b757d14bfe18c01f6a003ed38a3a4a3dcab0417efb457b71740e21411
saltedpassword = 6020c992a9b7cd3ca9e95b9a3e21b64911edb7983b3dd77bdcecda19f2756987

With "crypto" module, I wrote:

function SHA256Hash(password, salt, iteration) {
    var saltedpassword = salt + password;
    for(var i = 0; i < iteration-1; i++) { 
            console.log("saltedpassword = "+saltedpassword)
            var sha256 = crypto.createHash('sha256');
            sha256.update(saltedpassword);
            var saltedpassword = sha256.digest('hex');
    }       
    console.log("saltedpassword = "+saltedpassword)
    var sha256 = crypto.createHash('sha256');
    sha256.update(saltedpassword);
    return sha256.digest('base64');
}

Then call:

var hashedPassword = SHA256Hash("123456789", "ASIN", 3);

And receive:

saltedpassword = ASIN123456789
saltedpassword = 3362d80b757d14bfe18c01f6a003ed38a3a4a3dcab0417efb457b71740e21411
saltedpassword = 4795d40ae8ae797f0ce51dfe4b496bca68f6d1f4a264f4ca52348ddd65a2988d

The first two items are the same but the third item is different. Did I miss out something ?

Edited: As I compare to the Jasypt, CryptoJs generates similar keys. My question is how to tune "crypto" module to make it generate the same keys as CryptoJS and Jasypt do.

Just as a side node about the terminology. SHA256 as well as any other hashing algorithm is not encryption. `SHA256Encrypt` is therefore a confusing name. I know this is an old question but people like me still managed to find our way here. — quinz, Jun 07 '17 at 08:34

score 3 · Answer 1 · answered Dec 26 '12 at 02:25

3

Apparently I can't add comments to freakish's answer, so I'll write it here instead:

reset() works fine. The significant difference is you're converting the hash output to a hex string within the iteration loop.

answered Dec 26 '12 at 02:25

Jeff M

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score 1 · Answer 2 · answered Dec 26 '12 at 01:20

1

In the cryptojs example, finalize() returns raw binary data. In the crypto module example, digest() is returning a hex string. That difference in output means a difference in input when you iteratively re-hash.

answered Dec 26 '12 at 01:20

Jeff M

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Thanks, Jeff. I've tried changing to digest('binary') within the loop and it throws the same result now. For the cryptojs, when I tried to print out the output of finalize(), it show 'hex' string. So I thought I should use digest('hex'). – Mono Dec 27 '12 at 03:01

score 0 · Answer 3 · answered Dec 13 '12 at 11:35

I've done some tests and apparently this reset function ( in crypto-js ) messes up. I'm not sure what it does and I don't have enough patience to look for an issue. :) However, here's the working solution:

function SHA256Encrypt(password, salt, iteration) {
    var saltedpassword = salt + password;
    for(var i = 0; i < iteration-1; i++) {
        alert("saltedpassword = " + saltedpassword);
        saltedpassword = CryptoJS.SHA256( saltedpassword ).toString( CryptoJS.enc.Hex );
    }
    saltedpassword = CryptoJS.SHA256( saltedpassword );
    return saltedpassword.toString(CryptoJS.enc.Base64);
}

which makes both codes even more similar, which is good.

Thanks, freakish. That will make string encrypted by crypto-js identical to one created by crypto module. Do you have any idea how to make it the other way round ? One reason is when I compare these two with my Java snippet(using Jasypt 1.7). It turns out the crypto-js works similarly to the Jasypt. — Mono, Dec 14 '12 at 01:51

score 0 · Answer 4 · answered Mar 31 '14 at 11:29

Use PKDF2 instead!

Why are you not using the built-in PBKDF2 from node-crypto:

var hashedpw = crypto.pbkdf2Sync(password, salt, iterations, keysize);

and crypto-js:

var hashedpw = CryptoJS.PBKDF2(
    password, 
    salt, 
    { keySize: keysize/32, iterations: iterations }
);

Not only is it more secure than what you're trying to do by being much more expensive to compute than repeated hashing, it's also a lot easier to implement.

nodejs crypto module vs crypto-js

4 Answers4

Use PKDF2 instead!

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