tor-hscrypto

tor-hscrypto: Basic cryptography used by onion services

Overview

This crate is part of Arti, a project to implement Tor in Rust.

Onion services and the clients that connect to them need a few cryptographic operations not used by the rest of Tor. These include:

• A set of key-blinding operations to derive short-term public keys from long-term public keys.
• An ad-hoc SHA3-based message authentication code.
• Operations to encode and decode public keys as .onion addresses.
• A set of operations to divide time into different "periods". These periods are used as inputs to the DHT-style hash ring, and to the key-blinding operations.

This crate implements those operations, along with a set of wrapper types to keep us from getting confused about the numerous keys and nonces used for the onion services.

License: MIT OR Apache-2.0