secure-aes-gen.sh

#!/bin/bash
#
# Create a variable `$key` for use in powershell as a AES encyrption key
# constant with (ConvertFrom-SecureString)[https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.security/convertfrom-securestring?view=powershell-7.2)]
#
# param: $1 secret key (optional, default: secret)
# param: $2 cipher (optional, default: aes-256-cbc)
# output: An byte array (in decimals), the size of the encryption key (AES256 = 32 bytes)

genkey() {
  openssl enc -"${2:-aes-256-cbc}" -k "${1:-secret}" -iter +100 -P -md sha1 | \
     awk -F'=' '/key/{print $2}' | \
     sed -re 's/(.)(.)/\1\2\n/g' | \
     while read -r HEX 2>/dev/null; do
       test -z "$HEX" || echo $(( 16#$HEX ))
     done
     return 0
}

if key=("$(genkey "$@")"); then
  echo "${key[@]}" | tr '\n' ',' | sed -r 's/^(.*),$/\$key = @\(\1\)/'
  echo
fi