Overview

This proposal is about a new LeaseSet format with support for newer encryption types.

Motivation

The end-to-end cryptography used through I2P tunnels has separate encryption and signing keys. The signing keys are in the tunnel Destination, which has already been extended with KeyCertificates to support newer signature types. However, the encryption keys are part of the LeaseSet, which doesn't contain any Certificates. It is therefore necessary to implement a new LeaseSet format, and add support for storing it in the netDb.

A silver lining is that once LS2 is implemented, all existing Destinations can make use of more modern encryption types; routers that can fetch and read a LS2 will be guaranteed to have support for any encryption types introduced alongside it.

Specification

The basic LS2 format would be like this:

• dest
• published timestamp (8 bytes)
• expires (8 bytes)
• subtype (1 byte) (regular, encrypted, meta, or service)
• flags (2 bytes)
• subtype-specific part: - encryption type, encryption key, and leases for regular - blob for encrypted - properties, hashes, ports, revocations, etc. for service
• signature