How to get digest representation of CryptoJS.HmacSHA256 in JS

Question

I have to generate string representation of CryptoJS.HmacSHA256 in digest (bytes representation).

I need it because i have to duplicate python code which generate such digest in javascript:

print hmac.new("secret", "test", hashlib.sha256).digest()

')�kb��>�y+������:�o��H�   '

The goal is to duplicate behaviour of code above in javascript.

Could you please suggest me how to do this?

Answer 1

If you need raw bytes then CryptoJS does not seem to supply code for it. It is mentioned that this is because of lack of cross browser compatibility for Uint8Array and friends.

However, after searching, I did find some conversion code created by Vincenzo Ciancia:

CryptoJS.enc.u8array = {
    /**
     * Converts a word array to a Uint8Array.
     *
     * @param {WordArray} wordArray The word array.
     *
     * @return {Uint8Array} The Uint8Array.
     *
     * @static
     *
     * @example
     *
     *     var u8arr = CryptoJS.enc.u8array.stringify(wordArray);
     */
    stringify: function (wordArray) {
        // Shortcuts
        var words = wordArray.words;
        var sigBytes = wordArray.sigBytes;

        // Convert
        var u8 = new Uint8Array(sigBytes);
        for (var i = 0; i < sigBytes; i++) {
            var byte = (words[i >>> 2] >>> (24 - (i % 4) * 8)) & 0xff;
            u8[i]=byte;
        }

        return u8;
    },

    /**
     * Converts a Uint8Array to a word array.
     *
     * @param {string} u8Str The Uint8Array.
     *
     * @return {WordArray} The word array.
     *
     * @static
     *
     * @example
     *
     *     var wordArray = CryptoJS.enc.u8array.parse(u8arr);
     */
    parse: function (u8arr) {
        // Shortcut
        var len = u8arr.length;

        // Convert
        var words = [];
        for (var i = 0; i < len; i++) {
            words[i >>> 2] |= (u8arr[i] & 0xff) << (24 - (i % 4) * 8);
        }

        return CryptoJS.lib.WordArray.create(words, len);
    }
};

Note of course that bytes don't translate directly to characters; you cannot use a text compare to compare against ')�kb��>�y+������:�o��H� ' generated by python. For that you do need an encoder such as hexadecimals or base 64. In that case please look at the answer from Artjom instead.