Hash function for webhook obfuscation

[analystcmyk]

I am sending channel values to a webhook handler with sendget, like

sendget http://webhook.site/...?C2=$CH2&C3=$CH3

Now on the server side (understanding we cannot use TLS due to memory issues) I would like to do some kind of check that it is a valid request.

Although not foolproof, a hash function might help :

// for inspection
setChannelType 16 readonly
setChannelLabel 16  "Hash"

// set the hash value (example)
setChannel 16 hash $CH2+$CH3+970857320753905;

// send the hash value together with the data
sendget http://webhook.site/...?C2=$CH2&C3=$CH3&hash=$CH16

In this way at the webhook handler knowing the 'secret' 970857320753905 we can check the hash and if it matches, store the channel values. If not, we reject the request.

This is definitely no security, but at least it would not be trivial any more to dump fake data into the webhook handler.

Having a known hash like md5 would ease the serverside validation.

Question : is there a hash function available that could we can consider to use in script?