README

neutron

Build Status GoDoc

Self-hosted server for Protonmail client.

This project is not affiliated or supported by ProtonMail.

What is it?

Neutron is a server that will allow the ProtonMail client to be used with backends. Several backends are available right now:

  • IMAP: this will read and store messages on your IMAP server. Received messages will stay as is (that is, unencrypted) but messages saved from the web client will be encrypted. You will login to the web client with your IMAP username and password.
  • SMTP: this will send messages using your SMTP server. Messages are sent encrypted to the server. If a recipient's public key is not found, the server will decrypt the message before sending it to this recipient.
  • Filesystem: settings, contacts, keys are stored on disk. Keys are always stored encrypted.
  • Memory: all is stored in memory and will be destroyed when the server is stopped.

Neutron is modular so it's easy to create new backends and handle more scenarios.

Keep in mind that Neutron is less secure than ProtonMail: most servers don't use full-disk encryption and aren't under 1,000 meters of granite rock in Switzerland. Also, SRP is not yet supported (#35). If you use Neutron, make sure to donate to ProtonMail!

Install

Configuration

See config.json. You'll have to change IMAP and SMTP settings to match your mail server config.

{
	"Memory": {
		"Enabled": true,
		"Populate": false, // Populate server with default neutron user
		"Domains": ["emersion.fr"] // Available e-mail domains
	},
	"Imap": { // IMAP server config
		"Enabled": true,
		"Hostname": "mail.gandi.net",
		"Tls": true,
		"Suffix": "@emersion.fr" // Will be appended to username when authenticating
	},
	"Smtp": { // SMTP server config
		"Enabled": true,
		"Hostname": "mail.gandi.net",
		"Port": 587,
		"Suffix": "@emersion.fr" // Will be appended to username when authenticating
	},
	"Disk": { // Store keys, contacts and settings on disk
		"Enabled": true,
		"Keys": { "Directory": "db/keys" }, // PGP keys location
		"Contacts": { "Directory": "db/contacts" },
		"UsersSettings": { "Directory": "db/settings" },
		"Addresses": { "Directory": "db/addresses" }
	}
}
Usage

To generate keys for a new user the first time, just click Sign up on the login page and enter your IMAP credentials.

Options
  • -config: specify a custom config file
  • -help: show help

Build

Requirements:

  • Go (to build the server)
  • Node, NPM (to build the client)
# Get the code
go get -u github.com/emersion/neutron
cd $GOPATH/src/github.com/emersion/neutron

# Build the client
git submodule init
git submodule update
make build-client

# Start the server
make start
Docker
make build-docker
docker build -t neutron .
docker create -p 4000:4000 -v $PWD/config.json:/config.json -v $PWD/db:/db neutron

Backends

All backends must implement the backend interface. The main backend interface is split into multiple other backend interfaces for different roles: ContactsBackend, LabelsBackend and so on. This allows to build modular backends, e.g. a MessagesBackend which stores messages on an IMAP server with a ContactsBackend which stores contacts on a LDAP server and a SendBackend which sends outgoing messages to a SMTP server.

Writing a backend is just a matter of implementing the necessary functions. You can read the memory backend to understand how to do that. Docs for the backend are available here: https://godoc.org/github.com/emersion/neutron/backend#Backend

License

MIT

Documentation

The Go Gopher

There is no documentation for this package.

Source Files

Directories

Path Synopsis
Contains a generic interface for backends.
Contains a generic interface for backends.
disk
Stores data in files on disk.
Stores data in files on disk.
events
Provides backends to trigger events.
Provides backends to trigger events.
imap
Stores messages on an IMAP server.
Stores messages on an IMAP server.
memory
Stores data in memory.
Stores data in memory.
smtp
Sends messages with a SMTP server.
Sends messages with a SMTP server.
util
Backend utilities.
Backend utilities.
util/textproto
Provides utilities to parse and format messages.
Provides utilities to parse and format messages.
util/textproto/chunksplit
Provides a chunk splitter.
Provides a chunk splitter.
Parses the configuration file.
Parses the configuration file.
router
api