# Simple script which decode and encode messages based on user github key

ghcrypt.sh

#!/bin/bash
# Simple script which decode and encode messages based on user github key.
# Usage:
#   Encrypt:
#     echo "My secret is" | ./ghcrypt.sh -u ctrlok
#   Decrypt:
#     echo "BASE64SCRET"  | ./ghcrypt.sh -k ~/.ssh/id_rsa


while getopts "u:k:" opt
do
case $opt in
u) USERNAME=$OPTARG;;
k) SSH_KEY=$OPTARG;;
*) echo "No reasonable options found!";;
esac
done

if [ -n "${USERNAME}" ]; then
    TMP_PUB_RSA=$(mktemp)
    TMP_PUB_PEM=$(mktemp)
    OUTFILE=$(mktemp)
    KEYS=$(curl --silent https://api.github.com/users/${USERNAME}/keys | grep key | awk '{print $2" "$3}' | sed 's/^"\(.*\)"$/\1/')
    KEY=${KEYS[0]}
    echo $KEY > $TMP_PUB_RSA
    ssh-keygen -f $TMP_PUB_RSA -e -m PKCS8 > $TMP_PUB_PEM
    cat /dev/stdin | openssl rsautl -encrypt -pubin -inkey $TMP_PUB_PEM -ssl -out /dev/stdout | openssl enc -base64
    echo "Decrypt command: cat /dev/stdin | openssl enc -d -base64 | openssl rsautl -decrypt -inkey <%SSH_PRIVATE_KEY_PATH%> -out /dev/stdout" 1>&2
fi

if [ -n "${SSH_KEY}" ]; then
    echo "Running command: cat /dev/stdin | openssl enc -d -base64 | openssl rsautl -decrypt -inkey $SSH_KEY -out /dev/stdout" 1>&2
    cat /dev/stdin | openssl enc -d -base64 | openssl rsautl -decrypt -inkey $SSH_KEY -out /dev/stdout
fi

@ybogdanov Thanks!