Crate galileo_osnma

Galileo OSNMA

galileo-osnma is a Rust implementation of the Galileo OSNMA (Open Service Navigation Message Authentication) protocol. This protocol is used by the Galileo GNSS to sign cryptographically the navigation message data transmitted by its satellites, in order to prevent spoofing. Briefly speaking, galileo-osnma can process the navigation message data and OSNMA cryptographic data and check all the cryptographic data against an ECDSA public key and/or Merkle tree, in order to check the authenticity of the navigation data.

This library provides an Osnma struct that implements the OSNMA authentication as a black box. A user can feed data from INAV pages into Osnma and then request authenticated navigation data. Additionally, lower level functionalities of the OSNMA protocol are accessible in case finer control is needed.

This crate does not depend on std and can be used in small embedded microcontrollers. An example of this is given in the osnma-longan-nano crate.

Logging

The galileo-osnma crate makes extensive use of the log crate to log events related to the processing of the messages and the cryptographic functions.

Galmon integration

When this crate is built with the galmon feature, a galmon module is available, which can be used to read data using the Galmon transport protocol. The reader can be used to obtain INAV frames and OSNMA data from the Galmon tools, such as ubxtool.

An example of this functionality is given in galmon-osnma. This is a binary tool that reads data from the standard input using the Galmon transport protocol, and runs it through the Osnma black box, logging all the events that happen. See the quick start instructions about how to use this tool.

Features

When built with the default features, the crate does not require std. Additionally, the crate supports the following features:

• galmon. This enables support for reading the Galmon transport protocol and requires std.
• p521. This enables support for ECDSA P-521 public keys. These public keys defined in the OSNMA ICD, but currently only ECDSA P-256 keys are used in the signal-in-space.

Re-exports

• pub use merkle_tree::PublicKey;
• pub use types::InavBand;
• pub use types::MerkleTreeNode;
• pub use validation::Validated;

Modules

• bitfields
  Message bit fields.
• dsm
  DSM message collection.
• galmon
  Galmon integration.
• mack
  MACK message storage.
• maclt
  MAC Look-up Table
• merkle_tree
  Merkle tree.
• navmessage
  Navigation message storage and handling.
• storage
  OSNMA storage definitions.
• subframe
  Subframe collection.
• tesla
  TESLA keys and chain parameters.
• types
  Types used in galileo_osnma.
• validation
  Validation status.

Structs

• Gst
  GST (Galileo System Time)
• Osnma
  OSNMA “black box” processing.
• Svn
  Galileo SVN.
• SvnError
  SVN construction error.

Type Aliases

• Tow
  Time of week.
• Wn
  Galileo week number.