Bash helper function that decrypts Base64 encoded KMS secret.

decrypt_kms.bash

function decrypt_kms {
  if [ "$#" -ne 1 ]; then
    echo "Please provide base64 encoded kms-secret (aka. ciphertext-blob), e.g. decrypt_kms aasd123123lkjklj"
  else
    echo $(aws kms decrypt \
      --ciphertext-blob fileb://<(echo "$1" | base64 -d) \
      --output text \
      --query Plaintext | base64 --decode
    )
  fi
}