how to get Hmac code with javascript

Question

I can get a hmac sing using Python as following:

import hmac, base64, hashlib

def make_sign():
    hash_data = "data"
    secret = "this is secret"
    sha512 = hashlib.sha512
    hmac_obj = hmac.new(secret, hash_data, sha512)
    str_hash = hmac_obj.digest()
    sign = base64.b64encode(str_hash)
    hex_hash = hmac_obj.hexdigest()
    hex_sign = base64.b64encode(hex_hash)
    print "correct_sign:",sign
    print "hex_digest_sign:",hex_sign
make_sign()

output:

correct_sign: Lg4pXNCIpitNQt2DLU19qWb+FxdsYZlK4LLncfkTzSidrYoFJLNolUziRqh09B5HyRdCTEP7enZp6/Te34FK1g==
hex_digest_sign: MmUwZTI5NWNkMDg4YTYyYjRkNDJkZDgzMmQ0ZDdkYTk2NmZlMTcxNzZjNjE5OTRhZTBiMmU3NzFmOTEzY2QyODlkYWQ4YTA1MjRiMzY4OTU0Y2UyNDZhODc0ZjQxZTQ3YzkxNzQyNGM0M2ZiN2E3NjY5ZWJmNGRlZGY4MTRhZDY=

but with js, I can get hex_digest_sign, but I need to get correct_sign for web request.

function make_request() {
    hash_data = "data"
    secret = "this is secret"
    hmac = hmac_512(hash_data, secret)
    var sign = $.base64.encode(hmac),
    console.log("js_sign="+sign);
}

function hmac_512(message, secret) {
    var hmac = CryptoJS.algo.HMAC.create(CryptoJS.algo.SHA512, secret);
    hmac.update(message);
    var hash = hmac.finalize();
    return hash;
}

js output:

js_sign="MmUwZTI5NWNkMDg4YTYyYjRkNDJkZDgzMmQ0ZDdkYTk2NmZlMTcxNzZjNjE5OTRhZTBiMmU3NzFmOTEzY2QyODlkYWQ4YTA1MjRiMzY4OTU0Y2UyNDZhODc0ZjQxZTQ3YzkxNzQyNGM0M2ZiN2E3NjY5ZWJmNGRlZGY4MTRhZDY="

the correct sign is

correct_sign: Lg4pXNCIpitNQt2DLU19qWb+FxdsYZlK4LLncfkTzSidrYoFJLNolUziRqh09B5HyRdCTEP7enZp6/Te34FK1g==

how to get it in js?

Answer 1

I suspect that you are running into trouble with types and encoding. According to the CryptoJS source , the iterative hashing style that you are using returns a WordArray once you call finalize() .

With that, once you go to print the results, you are printing the contents of the WordArray .

The purpose for itterative hashing is typically if you have a large input, you can break it into chunks to work on one piece at a time. Try the below edit I made that removes this as it does not look like you need to iterate.

function hmac_512(message, secret) {
var newHMAC = CryptoJS.HmacSHA256(message, secret);
    return newHMAC;
}

The above will simply return the HMAC in string form which, once Base64 encoded, should match the result you see in Python.

For a working example, you can check out my Google drive encryption service that uses the cryptoJS HMAC. http://meowcrypt.com/

Hope this helps!