New algorithm request - Amazon v4 signature - AWS4-HMAC-SHA256

Hello,

I'd like a new algorithm being added to John the Ripper - the Amazon AWS4-HMAC-SHA256

Full documentation of implementing this hash can be found here:
https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-query-string-auth.html

Here is the example signature calculated and salts:

signature = 7f8ba2f53b6cc0485ed3e93642143fc66c1035b2f31dcb4d987431313b7dd4a3
longdate = 20130524T000000Z
date = 20130524
region = us-east-1
service = s3
canonical = 3bfa292879f6447bbcda7001decf97f4a54dc650c8942174ae0a9121cf58ad04

$stringtosign is AWS4-HMAC-SHA256\n$longdate\n$date/$region/$date/aws4_request\n$canonical

So my stringtosign would be AWS4-HMAC-SHA256\n20130524T000000Z\n20130524/us-east-1/s3/aws4_request\n3bfa292
879f6447bbcda7001decf97f4a54dc650c8942174ae0a9121cf58ad04

The goal is to recover the secret which is 1234 in the above example

How the algorithm works:

kdate = HMACSHA256(key="AWS4"+secret, message=date).digest() // no hex, just raw digest
kregion = HMACSHA256(key=kdate, message=region).digest()
kservice = HMACSHA256(key=kregion, message=service).digest()
signingkey = HMACSHA256(key=kservice, message="aws4_request").digest()

signature =HMACSHA256(key=signingkey, message=stringtosign).hexdigest() // digest hex-encoded

Sincerely

Start with the linked AWS SigV4 query-string authentication documentation and verify the supplied signature, salts, and secret example. There is no repository file, test, or entry point identified in the issue; done means John the Ripper can recover the stated secret from AWS4-HMAC-SHA256 signatures using the documented key-derivation steps.