Generate Testing Certificate
----------------------------

The script `openssl-ca.sh` allows you to create a certificate and key that you
can use for a test-setup of RAUC.

To generate the required files, execute

  ./openssl-ca.sh

This will generate a folder `openssl-ca/` that contains the generated openssl
configuration file and a development certificate and key.

To use them in your BSP in order to sign and verify bundles, you have to:

1) Make the target rauc package use the generated keyring file:

   Copy the keyring file `dev/ca.cert.pem` into your projects meta layer under
   `recipes-core/rauc/files` and add a simple .bbappend file
   `recipes-core/rauc/rauc-conf.bbappend` that adds the keyring file to the rauc
   config package search path:

     FILESEXTRAPATHS:prepend := "${THISDIR}/files:"

2) Make your bundle recipe use the generated key and certificate:

   Copy the key file `dev/private/development-1.key.pem` and the cert file
   `dev/development-1.cert.pem` to your projects meta layer in a global `files`
   folder.

   In your bundle recipe, let the variables `RAUC_KEY_FILE` and `RAUC_CERT_FILE`
   point to these key and cert files:

     RAUC_KEY_FILE = "${COREBASE}/meta-<layername>/files/development-1.key.pem"
     RAUC_CERT_FILE = "${COREBASE}/meta-<layername>/files/development-1.cert.pem"

Now you are able to build and sign bundles that contain a rootfs that will
allow RAUC to verify the content of further bundles.