AWS Signature 4 SHA256 Key Hashing

Hi All,

I've been trying to sign an AWS Signature 4 http request using both the Java Cryptography Library plugin and the Cryptography tools plugin.  The Appian code near the bottom is using the latter, but I've been getting the same results using the macsignature function from the Java library.

AWS has sample data to validate the process here: https://docs.aws.amazon.com/general/latest/gr/signature-v4-examples.html

The pertinent part is..

key = 'wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY'

kSecret = '41575334774a616c725855746e46454d492f4b374d44454e472b62507852666943594558414d504c454b4559'  which is Hexencode("AWS4" + key)

kDate = '969fbb94feb542b71ede6f87fe4d5fa29c789342b0f407474670f0c2489e0a0d'

kRegion = '69daa0209cd9c5ff5c8ced464a696fd4252e981430b10e3d3fd8e2f197d7a70c'

kService = 'f72cfd46f26bc4643f06a11eabb6c0ba18780c19a8da0c31ace671265e3c87fa'

kSigning = 'f4780e2d9f65fa895f9c67b32ce1baf0b0d8a43505a000a1a9e090d414db404d'

Your program should generate the following values for the values in getSignatureKey. Note that these are hex-encoded representations of the binary data; the key itself and the intermediate values should be in binary format.

Using the below code I get the right result for kDate, but nothing is right after that. I'm assuming the reason is that I'm getting hex string back and I need to input a binary value, but I've tried encoding the subsequent keys to base64, but I still don't get the right values. To be honest I've tried just about everything I can think of in terms of hex-text binary encoding of the keys and values and I can't get the right values.  I was able to solve this with a SQL Server Function before, but that isn't an option now. Can anybody help determine if A) this is possible with Appian's Collating and Charater Encoding and B) If so how?

Please and thank you SO much for any guidance!

load(
local!key: "AWS4wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY",
local!date: "20120215",
local!region: "us-east-1",
local!service: "iam",
local!request: "aws4_request",
local!kdate: hmacsha256hash(local!key, local!date),
local!kRegion: hmacsha256hash(local!kdate, local!region),
local!kService: hmacsha256hash(local!kRegion, local!service),
local!signing: hmacsha256hash(local!kService, local!request),
local!signing
)

-JJ