mildsunrise / ilo-protocol

🖥 Node.js implementation of HPE iLO 4 remote console protocol

ilo-protocol

Node.js module to interact with iLO (Integrated Lights-Out) modules in HPE servers. iLO 4 v2.55 (and possibly other versions) are supported.

npm install ilo-protocol

💡 Examples  •  📚 API reference

The focus is on implementing the remote console protocol, which allows you to manage the server as if you were sitting at the KVM. You can:

• See the server's screen
• Use the keyboard / mouse
• Virtual media: mount a file / device from your computer that the server will see as a real SCSI device (hard drive, CDROM or floppy disk)
• Press the power button, trigger a power cycle or system reset

In addition to implementing the protocol itself, the repository also comes with a fully-functional client in its examples, see examples.

Protocol overview

Initiation

First, the /json/rc-info endpoint in the HTTPS webserver is called. Like the whole API, it's authenticated with a 16-byte session key. It returns, among other things:

• the network ports to connect to
  • remote console port
  • virtual media port
• the main encryption key to use for the session
• list of supported extra protocol features

From there the protocol itself starts. The client opens a TCP connection to the remote console port. It initiates a handshake to negotiate a remote console session, where the client authenticates to the server by sending the session key mentioned before, optionally (sort of) XOR-ed with the encryption key.

The server may reject the session because of several reasons (no license, wrong authentication, no free sessions, etc.), or it may accept it. If accepted, but another session is in progress, busy negotiation occurs. There's the option to share the session with the other user, or seize it from them. Seizing requires confirmation from the other user.

After that, another connection is opened to the same port, but a slightly different handshake is used which negotiates a command session. That session doesn't seem to be of much use so we'll focus on the remote console session from now on.

Server data (video stream)

TODO: document protocol

State graph

Client data (user input)

TODO: document protocol

Encryption

Once the handshake is over, the server may choose to switch the remote console session into RC4, AES128 or AES256 encryption. The encryption only applies to the remote console session, to both server and client data. Other sessions, like the command session or virtual media traffic (data read / written) are not encrypted, at least in the implemented version.

The ciphers are always used as stream ciphers, i.e. block cyphers are used in OFB mode.

Virtual media

TODO: document protocol

WebSocket support

Newer versions of the iLO (FIXME: document which) come with an HTML5 client rather than a Java applet.
This client uses exactly the same protocols, but over WebSockets rather than TCP connections.

That's very nice because if the webserver uses HTTPS (which it does by default) those WebSockets will also go over TLS which means we finally got decent security! The iLO doesn't use the in-protocol encryption mentioned above when the remote console session is over WebSockets.

TODO: document websocket endpoints, add support in API, make examples prefer WS when possible.

Usage

This library only has some dependency on Node.js APIs (streams and crypto) but is designed to be relatively easy to run in the browser.

Only the protocol itself is implemented; the user must handle decoded data, render it to the screen, listen to user input, and even network and filesystem I/O. The only exception is the rest module, which uses Got to make HTTPS requests.

The modules are structured as follows (internal APIs omitted):

• rest: partial client for the REST API

• rc/: implements the remote console session

  • rc/handshake: initial handshake (authentication, busy negotiation)
  • rc/telnet: outer layer that kicks in after the handshake (processes client & server data, mostly encryption)
  • rc/video: decodes the video stream from telnet
  • rc/command: formats commands sent to the server, both in the handshake and afterwards (through telnet)

• vm/: implements the virtual media sessions

  • vm/handshake: initial handshake
  • vm/scsi: protocol implementation, simulates SCSI device behavior (for now, only CDROM is supported)

Examples

The examples directory contains many examples of using the library.

app.ts

It's a completely functional GTK-based client, and it shows usage of (almost) all protocol features.
To try it out:

npm install
$(npm bin)/ts-node examples/app.ts <arguments>

Note: It's currently hardcoded to assume Linux (evdev) keycodes, so keyboard input probably won't work correctly on other OSes, or ancient Linux installs.

Note: This example depends on romgrk/node-gtk#252, package.json already installs that branch from my repo, but you need to do npm explore node-gtk -- npm run build:full after npm install to make sure it picks up the changes.

vm_cdrom.ts

Simple program that mounts the supplied file as a CDROM device.
To try it out:

npm install
$(npm bin)/ts-node examples/vm_cdrom.ts <arguments>