The Portier Broker reference implementation

This is the reference implementation of the Broker side of the Portier_ protocol specification_. Feedback is welcome on GitHub_.

.. _Portier: https://portier.github.io/ .. _specification: protocol.md .. _GitHub: https://github.com/portier/portier-broker

How to run your own broker

Portier is specified such that everyone can run their own Broker instance. You can point your Relying Parties at your own broker, so that you do not have to depend on the broker run by the Portier project.

Currently, this project does not ship any binaries. However, once you have the Rust toolchain installed_, building portier broker is very simple:

.. code-block:: shell

$ cargo install portier_broker

This should fetch and install the Portier broker. The binary is installed into ~/.cargo/bin/ by default. Running the portier-broker binary requires a short configuration file. An example is provided in config.toml.dist.

To run the broker, invoke it with the path to a configuration file:

.. code-block:: shell

$ portier-broker config.toml

You can also supply all required settings as environment variables and completely omit the configuration file.

You will also need a Redis server and an outgoing SMTP server.

.. _installed: https://doc.rust-lang.org/book/getting-started.html

should be in the format <host>:<port>. The username and password fields are optional, and may be set to provide login credentials.

Configuration

See config.toml.dist for an example configuration file. This file includes reasonable default values for most settings, but you must explicitly set:

• server.public_url: The server's public-facing URL.
• crypto.keyfiles: An array of paths to encryption keys, or
• crypto.keytext: The text of an encryption key in PEM format (takes precedence over keyfiles).
• redis.url: The URL of a Redis server for temporary session storage.
• smtp.from_address: The email address that outgoing mail is from.
• smtp.server: The host and port of the outgoing mail server.

If necessary, set smtp.username and smtp.password to your SMTP server's username and password.

To support in-browser Google Authentication for Gmail users, you must also specify:

• google.client_id: Your Google OAuth API Client ID

You can create encryption keys with openssl genrsa 4096 > private.pem

The complete list of available values are:

[server] section:

=============== ====================== ===================== config.toml Environment Variable Default =============== ====================== ===================== listen_ip BROKER_IP "127.0.0.1" listen_port BROKER_PORT 3333 public_url BROKER_PUBLIC_URL (none) allowed_origins BROKER_ALLOWED_ORIGINS (none (unrestricted)) =============== ====================== =====================

[headers] section:

=============== ==================== ================ config.toml Environment Variable Default =============== ==================== ================ static_ttl BROKER_STATIC_TTL 604800 (1 week) discovery_ttl BROKER_DISCOVERY_TTL 604800 (1 week) keys_ttl BROKER_KEYS_TTL 86400 (1 day) =============== ==================== ================

[crypto] section:

=============== ==================== ================ config.toml Environment Variable Default =============== ==================== ================ token_ttl BROKER_TOKEN_TTL 600 (10 minutes) keyfiles BROKER_KEYFILES [] (empty array) keytext BROKER_KEYTEXT (none) =============== ==================== ================

[redis] section:

=============== ==================== ================ config.toml Environment Variable Default =============== ==================== ================ url BROKER_REDIS_URL (none) session_ttl BROKER_SESSION_TTL 900 (15 minutes) cache_ttl BROKER_CACHE_TTL 3600 (1 hour) =============== ==================== ================

[smtp] section:

=============== ==================== ========= config.toml Environment Variable Default =============== ==================== ========= from_name BROKER_FROM_NAME "Portier" from_address BROKER_FROM_ADDRESS (none) server BROKER_SMTP_SERVER (none) username BROKER_SMTP_USERNAME (none) password BROKER_SMTP_PASSWORD (none) =============== ==================== =========

[limit] section:

=============== ====================== ======= config.toml Environment Variable Default =============== ====================== ======= per_email BROKER_LIMIT_PER_EMAIL "5/min" =============== ====================== =======

[google] section:

=============== ======================= ======= config.toml Environment Variable Default =============== ======================= ======= client_id BROKER_GOOGLE_CLIENT_ID (none) =============== ======================= =======

[domain_overrides] section:

This section contains arbitrary domain names, mapped to a list of WebFinger-like links, allowing local configuration on the broker to skip and override WebFinger queries for some domains.

This is currently most useful for G Suite domains that don't respond to WebFinger, which can be specified as:

.. code-block:: toml

[[domain_overrides."my-apps-domain.example"]] rel = "https://portier.io/specs/auth/1.0/idp/google" href = "https://accounts.google.com"

When the [google] section is present, default overrides are added for gmail.com and googlemail.com.

Contributing

If you want to hack on the broker code, clone this repository. If you have the Rust toolchain installed (see above), you can run cargo build to build the project in debug mode. cargo run -- <config-file> will run the project. You will have to set up your own configuration file; use config.toml.dist as a template.

The broker binds to 127.0.0.1:3333 by default. It only speaks HTTP, so you must run it behind a reverse proxy like nginx to expose it to the web via TLS. Note that the broker will serve up files from the .well-known directory in the current working directory when executed; this makes it relatively easy to request a certificate from Let's Encrypt_.

If you want to test a custom identity provider, you may want to do so locally over plain HTTP, without TLS. This can be enabled with a compile-time flag as follows: cargo run --features insecure -- <config-file>. With this flag, WebFinger queries are sent over plain HTTP, and plain HTTP links in the WebFinger response are allowed.

If you want to test support for well-known identity providers, you will need to configure them. For Google, you can request credentials through their API Manager_.

It is not necessary to run your own email server for testing. Instead, use MailCatcher_ or MailHog_ to get a dummy SMTP interface. The relevant part of configuration to use MailCatcher with default settings can look like this:

.. code-block:: shell

[smtp]

Display name for confirmation emails - Default: "Portier"

from_name = "Portier"

Sender address for confirmation emails - Default: (none)

from_address = "test@example.com"

Outgoing mailserver address - Default: (none)

server = "127.0.0.1:1025"

To test your changes, you will need to set up a Relying Party; so far, the Python demo-rp code has been used. This is a very bare-bones implementation that only serves to prove authentication to the broker.

.. _demo-rp: https://github.com/portier/demo-rp .. _Let's Encrypt: https://letsencrypt.org/ .. _API Manager: https://console.developers.google.com/apis/credentials .. _MailCatcher: https://mailcatcher.me/ .. _MailHog: https://github.com/mailhog/MailHog