Kevin Cooper Kevin Cooper - 1 month ago 8
PHP Question

Javascript: Equivalent of PHP's hash_hmac() with RAW BINARY output?

I am connecting to the Amazon Product Advertising API, and to sign my request I need to base64-encode the raw binary output of an HMAC-SHA256 hash.

In the PHP documentation for hash_hmac, the fourth parameter

bool $raw_output
controls whether the output is raw binary data (true) or lowercase hexits (false). My program works in PHP by simply setting that parameter to true.

However, I am now trying to port this over to Javascript. I tried using the CryptoJS.HmacSHA256() function, but it seems to be returning the lowercase hexits. How can I convert this to binary?

I have tried the following according to the CryptoJS documentation, but both outputs are identical:

var hash = CryptoJS.HmacSHA256("hello", "key");

Answer Source

This is explained in their documentation. Try this:

var hash = CryptoJS.HmacSHA256("Message", "Secret Passphrase");

var base64 = hash.toString(CryptoJS.enc.Base64);

You need to include for this. If you didn't include this, CryptoJS.enc.Base64 will be undefined and fallback to the default.

Working demo: