Simple bash/zsh script that calculates the Base64 HMAC for the given input string, algorithm and secret.
Example usage:
export HMAC_INPUT="date: Thu, 22 Jun 2017 17:15:21 GMT\nGET /requests HTTP/1.1"
./hmac-generator.sh -a sha256 -s secret $HMAC_INPUT
This will generate the Base64 SHA256 HMAC for the input message:
date: Thu, 22 Jun 2017 17:15:21 GMT
GET /requests HTTP/1.1
.... and the secret secret.
Output can be compared with the online HMAC generator that can be found here: https://dinochiesa.github.io/hmachash/index.html