# Custom IO Callback Example

This is an example to demonstrate how the custom IO callbacks can be used to
facilitate a TLS connection using any medium. Here we chose the medium: "File System".

Other transports might be:
* USB Serial connection
* Bluetooth
* RFID
* Wifi
* Ethernet

These examples use the wolfSSL Custom IO Callbacks to read and write to the file
system and perform a successful handshake.

Building the examples:

From the wolfssl directory:
```
./configure --enable-debug
sudo make install
```

**NOTE:** Debug was enabled in case a user wishes to use the verbose flag to see
          what is happening in real time:

From the file-server directory:
```
make
```

From the file-client directory:
```
make
```

Usage examples:

From the file-server directory:
./start-server
./start-server -v
./start-server -verbose

From the file-client directory:
./start-client
./start-client -v
./start-client -verbose

(-v and -verbose accomplish the same thing)

## SCRIPTS

The scripts provided attempt to make testing easier.

* file-server/check.sh
    - starts the server in a background shell and runs the client

USAGE:
    ./check.sh
    ./check.sh -v
    ./check.sh -verbose

* file-client/clean-io-files.sh
    - If something happens and there is leftover junk in the io files run this
      script to quickly cleanup before next round of testing.

USAGE:
    ./clean-io-files.sh