Add example script to get secret from CLI (#18)

commit a8a28a4c327bfe74244f32444ed173e65ff35db3
Author: Knut Ahlers <knut@ahlers.me>
Date:   Tue Jun 2 14:55:31 2020 +0200

    Adjust coding-style to match other scripts, simplify a little

    Signed-off-by: Knut Ahlers <knut@ahlers.me>

commit 625ddd0a9d
Author: bestlibre <github@bestlibre.org>
Date:   Mon May 11 14:51:10 2020 +0200

    Add exemple script to get secret from CLI

closes #18

Signed-off-by: Knut Ahlers <knut@ahlers.me>

cli_get.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+set -euo pipefail
+
+deps=(curl jq)
+for cmd in "${deps[@]}"; do
+	which ${cmd} >/dev/null || {
+		echo "'${cmd}' util is required for this script"
+		exit 1
+	}
+done
+
+# Get URL from CLI argument
+url="${1:-}"
+[[ -n $url ]] || {
+	echo "Usage: $0 'URL to get the secret'"
+	exit 1
+}
+# normalize url and extract parts
+url="${url/|/%7C}"
+host="${url%%/\#*}"
+idpass="${url##*\#}"
+pass="${idpass##*\%7C}"
+id="${idpass%%\%7C*}"
+geturl="${host}/api/get/${id}"
+
+# fetch secret and decrypt to STDOUT
+curl -sSf "${geturl}" | jq -r ".secret" |
+	openssl aes-256-cbc -base64 -pass "pass:${pass}" -md md5 -d 2>/dev/null