nymea remote proxy server

---

The nymea remote proxy server is the meeting point of nymea servers and nymea clients in order to establishing a secure remote connection.

Build

In order to build the proxy server you need to install the qt default package.

apt install qt5-default

Build from source

Change into the source directory and run following commands

$ cd nymea-remoteproxy
$ mkdir build
$ cd build
$ qmake ../
$ make -j$(nproc)

In the build directory you can find the resulting library and binary files.

If you want to start the proxy server from the build directory, you need to export the library path before starting the application:

$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$(pwd)/libnymea-remoteproxy:$(pwd)/libnymea-remoteproxyclient
$ ./server/nymea-remoteproxy -c ../nymea-remoteproxy/nymea-remoteproxy.conf

Build debian package

$ apt install crossbuilder
$ cd nymea-remoteproxy
$ crossbuilder

Install

From repository

There is a public version available in the nymea repository.

$ apt install nymea-remoteproxy nymea-remoteproxy-client nymea-remoteproxy-monitor

This will install a systemd service called nymea-remoteproxy.service and the client application for testing.

From build directory

Simply run following command in the build dir:

$ sudo make install

Configure

The package will deliver a default configuration file with following content (/etc/nymea/nymea-remoteproxy.conf):

[ProxyServer]
name=nymea-remoteproxy
writeLogs=false
logFile=/var/log/nymea-remoteproxy.log
logEngineEnabled=false
monitorSocket=/tmp/nymea-remoteproxy-monitor.sock
jsonRpcTimeout=10000
authenticationTimeout=8000
inactiveTimeout=8000
aloneTimeout=8000

[AWS]
region=eu-west-1
authorizerLambdaFunction=system-services-authorizer-dev-checkToken
awsCredentialsUrl=http://169.254.169.254/latest/meta-data/iam/security-credentials/EC2-Remote-Connection-Proxy-Role

[SSL]
certificate=/etc/ssl/certs/ssl-cert-snakeoil.pem
certificateKey=/etc/ssl/private/ssl-cert-snakeoil.key
certificateChain=

[WebSocketServer]
host=127.0.0.1
port=443

[TcpServer]
host=127.0.0.1
port=80

Test

In order to run the test, you can call make check in the build directory or run the resulting executable:

$ nymea-remoteproxy-tests-offline
$ nymea-remoteproxy-tests-online

Test coverage report

If you want to create a line coverage report from the tests simply run following command in the source directory:

$ apt install lcov gcovr
$ ./create-coverage-html.sh

The resulting coverage report will be place in the coverage-html directory.

Server usage

In order to get information about the server you can start the command with the --help parameter.

$ nymea-remoteproxy --help

Usage: nymea-remoteproxy [options]

The nymea remote proxy server. This server allowes nymea-cloud users and registered nymea deamons to establish a tunnel connection.

Version: 0.1.5
API version: 0.3

Copyright © 2018 Simon Stürz <simon.stuerz@nymea.io>


Options:
  -h, --help                           Displays this help.
  -v, --version                        Displays version information.
  -l, --logging <logfile>              Write log file to the given logfile.
  -d, --development                    Enable the development mode. This
                                       enabled the server assumes there are
                                       static AWS credentials provided to
                                       aws-cli.
  -m, --mock-authenticator             Start the server using a mock
                                       authenticator which returns always true.
  -c, --configuration <configuration>  The path to the proxy server
                                       configuration file. The default is
                                       ~/.config/nymea/nymea-remoteproxy.conf
  --verbose                            Print more verbose.

Proxy server API

Once a client connects to the proxy server, he must authenticate him self by passing the token received from the nymea-cloud mqtt connection request.

Basic flow

First client

1. Connect to the proxy server
2. Say hello, in order to know the version, name and API version of the server
3. Authenticate with a token
4. Wait for the tunnel established notification

Second client

1. Connect to the proxy server
2. Say hello, in order to know the version, name and API version of the server
3. Authenticate with a token (this has to be the same token as the first client showed)
4. Wait for the tunnel established notification

Once both clients are authenticated, the proxy server will send the RemoteProxy.TunnelEstablished notification containing the information of the other tunnel participent. Any traffic coming from he socket is from the remote partner, and any messge sent to the socket will go to the remote partner.

If anything goes wrong, or the tunnel partner disconnects from the proxy, the server will close the other client connection. If any data will be sent between Authenticate method and TunnelEstablished notification, the server will close the socket.

Message format

Request

{
    "id": integer,
    "method": "Namespace.Method",
    "o:params" { }
}

Response

{
    "id": integer,
    "status": "string",
    "o:params" { },
    "o:error": "string"
}

Notification

{
    "id": integer,
    "notification": "Namespace.Notification",
    "o:params" { }
}

Say Hello

Request

{
    "id": 0,
    "method": "RemoteProxy.Hello"
}

Response

{
    "id": 0,
    "params": {
        "apiVersion": "0.2",
        "name": "community-server",
        "server": "nymea-remoteproxy",
        "version": "0.1.2"
    },
    "status": "success"
}

Proxy server

Authenticate the connection

The first data a client must send to the proxy server is the authentication request. This request contains the token which will be verified agains the nymea-cloud infrastructure and a nonce which has to be uniq for each connection attempt and shared between the 2 clients. The uuid should be a persistant uuid for this client and the name should make clear which type of connection this is and which client is connecting. The name and uuid will be sent to the tunnel partner during the tunnel establishmend.

Request

{
    "id": 1,
    "method": "Authentication.Authenticate",
    "params": {
        "uuid": "string",
        "name": "string",
        "token": "tokenstring"
        "nonce": "nonce"
    }
}

Response

• On Success: If the token was authenticated successfully, the response will look like this:

    {
        "id": 1,
        "status": "success"
    }
  

• On Failure If the token was invalid, the response will look like this and the server will close the connection immediatly:

    {
        "id": 1,
        "status": "error",
        "error": "Invalid token. You are not allowed to use this server."
    }
  

Tunnel established

Once the other client is here and ready, the server will send a notification to the clients indicating that the tunnel has been established successfully. This message is the last data comming from the proxy server.

Important: Any data traffic following after this notification comes from the tunnel endpoint, not from the proxy server any more.

{
    "id": "0",
    "notification": "RemoteProxy.TunnelEstablished",
    "params": {
        "name": "String",
        "uuid": "String"
    }
}

Introspect the API

Request

{
    "id": 0,
    "method": "RemoteProxy.Introspect"
}

Response

{
    "id": 1,
    "params": {
        "methods": {
            "Authentication.Authenticate": {
                "description": "Authenticate this connection. The returned AuthenticationError informs about the result. If the authentication was not successfull, the server will close the connection immediatly after sending the error response. The given id should be a unique id the other tunnel client can understand. Once the authentication was successfull, you can wait for the RemoteProxy.TunnelEstablished notification. If you send any data before getting this notification, the server will close the connection. If the tunnel client does not show up within 10 seconds, the server will close the connection.",
                "params": {
                    "name": "String",
                    "o:nonce": "String",
                    "token": "String",
                    "uuid": "String"
                },
                "returns": {
                    "authenticationError": "$ref:AuthenticationError"
                }
            },
            "RemoteProxy.Hello": {
                "description": "Once connected to this server, a client can get information about the server by saying Hello. The response informs the client about this proxy server.",
                "params": {
                },
                "returns": {
                    "apiVersion": "String",
                    "name": "String",
                    "server": "String",
                    "version": "String"
                }
            },
            "RemoteProxy.Introspect": {
                "description": "Introspect this API.",
                "params": {
                },
                "returns": {
                    "methods": "Object",
                    "notifications": "Object",
                    "types": "Object"
                }
            }
        },
        "notifications": {
            "RemoteProxy.TunnelEstablished": {
                "description": "Emitted whenever the tunnel has been established successfully. This is the last message from the remote proxy server! Any following data will be from the other tunnel client until the connection will be closed. The parameter contain some information about the other tunnel client.",
                "params": {
                    "name": "String",
                    "uuid": "String"
                }
            }
        },
        "types": {
            "AuthenticationError": [
                "AuthenticationErrorNoError",
                "AuthenticationErrorUnknown",
                "AuthenticationErrorTimeout",
                "AuthenticationErrorAborted",
                "AuthenticationErrorAuthenticationFailed",
                "AuthenticationErrorProxyError"
            ],
            "BasicType": [
                "Uuid",
                "String",
                "Int",
                "UInt",
                "Double",
                "Bool",
                "Variant",
                "Object"
            ]
        }
    },
    "status": "success"
}

Proxy server

Server monitor

The server provides a live monitor interface on a local socket server. You can follow the monitor data with:

$ sudo socat - UNIX-CONNECT:/tmp/nymea-remoteproxy-monitor.sock

There is also the package nymea-remoteproxy-monitor package and application which gives you a nice overview about whats going on on the proxy server.

$ nymea-remoteproxy-monitor --help

Usage: nymea-remoteproxy-monitor [options]

The nymea remote proxy monitor allowes to monitor the live server activity on the a local instance.

Server version: 0.1.5
API version: 0.3

Copyright © 2018 Simon Stürz <simon.stuerz@nymea.io>


Options:
  -h, --help             Displays this help.
  -v, --version          Displays version information.
  -s, --socket <socket>  The socket descriptor for the nymea-remoteproxy
                         monitor socket. Default is
                         /tmp/nymea-remoteproxy-monitor.sock

Client usage

The client allowes you to test the proxy server and create a dummy client for testing the connection.

$ nymea-remoteproxy-client --help

Usage: nymea-remoteproxy-client [options]

The nymea remote proxy client application. This client allowes to test a server application as client perspective.

Version: 0.1.5
API version: 0.3

Copyright © 2018 Simon Stürz <simon.stuerz@nymea.io>


Options:
  -h, --help           Displays this help.
  -v, --version        Displays version information.
  -u, --url <url>      The proxy server url. Default
                       wss://dev-remoteproxy.nymea.io:443
  -t, --token <token>  The AWS token for authentication.
  -i, --igore-ssl      Ignore SSL certificate errors.
  --name <name>        The name of the client. Default nymea-remoteproxyclient
  --uuid <uuid>        The uuid of the client. If not specified, a new one will
                       be created
  --verbose            Print more information about the connection.
  --very-verbose       Print the complete traffic information from the
                       connection.

Testing a local server

With following steps you can test a local instance with a self signed certificate.

Start the server

In order to test a connection and play with the server API, you can install the proxy server on your machine and try to connect to it.

$ sudo apt update
$ sudo apt install nymea-remoteproxy nymea-remoteproxy-client

Once installed, the nymea-remoteproxy will start automatically using the default configurations shipped in /etc/nymea/nymea-remoteproxy.conf. Using this file allowes you to configure the server for your test purposes.

The only thing you need is a certificate, which can be loaded from the server. The server does not support insecure connection for now. If you don't have any certificate, you can create one for testing.

Note: you can enter whatever you like for the certificate.

$ cd /tmp/
$ openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout test-proxy-certificate.key -out test-proxy-certificate.crt

Now place the certificate and the key where they belong:

$ sudo cp /tmp/test-proxy-certificate.crt /etc/ssl/certs/
$ sudo cp /tmp/test-proxy-certificate.key /etc/ssl/private/

Change following configuration in the /etc/nymea/nymea-remoteproxy.conf:

...
certificate=/etc/ssl/certs/test-proxy-certificate.crt
certificateKey=/etc/ssl/private/test-proxy-certificate.key
...

Now stop the proxy server and start it manually:

$ sudo systemctl stop nymea-remoteproxy.conf

Note: the -m starts the proxy with a dummy authenticator, which allowes to use any token, it will always be authenticated and should be used only on localhost running servers.

$ sudo nymea-remoteproxy -c /etc/nymea/nymea-remoteproxy -m --verbose

Connect two clients

Once the server is up and running with the dummy authenticator, you can try to connect to the service using the nymea-remoteproxy-client in a new terminal.

Note: assuming you are starting the client on the same system as the server:

$ nymea-remoteproxy-client -i -u wss://localhost -t "blubtoken"

Open a second terminal and start the same command again.

Note: assuming you are starting the client on the same system as the server:

$ nymea-remoteproxy-client -i -u wss://localhost -t "blubtoken"

You can follow the connection flow on both sides using the --very-verbose option.

License

This is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 3 of the License.