BaseElements and FM17

Hi,

I am looking to move some functionality away from BaseElements (4.0.3) and into Filemaker Pro's native functions.
There are three functions that are used that I need to migrate.
Could somebody please help me 'translate' the following line away from using BaseElements (BE) and into Filemaker's own functions?

1.
BE_HMAC_Deprecated ( $queryString ; $$_API_Key ; BE_MessageDigestAlgorithm_SHA256_Deprecated ; BE_Encoding_Base64_Deprecated )

As I understand it, the new function would be:
CryptAuthCode( data; algorithm; key)
yet the BE function has four parameters, and Filemaker has only three, and I'm not sure how to "translate" the third and fourth parameters in the above line into the Filemaker equivalent.
Details at: https://baseelementsplugin.zendesk.com/hc/en-us/articles/204700668-BE-HMAC-Deprecated

2.
I cannot find the "BE_MessageDigestAlgorithm _SHA256_Deprecated" details on the BE web page, yet I find something with a similar name similar at:
https://baseelementsplugin.zendesk.com/hc/en-us/articles/204700878-BE-MessageDigest-Deprecated
If it is the same as the then what is the Filemaker equivalent?

3.
Similar situation with the "BE_Encoding_Base64_Deprecated". The way the function in the command above shows no parameters being used, yet the BE reference guide (https://baseelementsplugin.zendesk.com/hc/en-us/articles/205350447-BE-Base64-Encode-Deprecated) shows a single parameter required.

So as my command works with BE loaded as a plugin, I am wondering if it is even using those third and fourth parameters at all.
Can anybody give me a hand please?

Cheers,
Greg