Module signal 

WebRTC Signaling Data Structures

This module defines the core signaling data structures used in OpenMina’s WebRTC peer-to-peer communication system. It provides the message types for WebRTC connection establishment, including offers, answers, and connection responses.

Overview

WebRTC requires a signaling mechanism to exchange connection metadata between peers before establishing a direct peer-to-peer connection. This module defines the data structures for:

• Offers: Initial connection requests containing SDP data and peer information
• Answers: Responses to offers containing SDP data and identity verification
• Connection Responses: Acceptance, rejection, and error handling for connections
• Encryption Support: Encrypted versions of signaling messages for security

WebRTC Signaling Flow

1. Peer A creates an Offer with SDP data, chain ID, and target peer information
2. The offer is transmitted through a signaling method (HTTP, WebSocket, etc.)
3. Peer B receives and validates the offer (chain ID, peer ID, capacity)
4. Peer B responds with a P2pConnectionResponse:
   • P2pConnectionResponse::Accepted with an Answer containing SDP data
   • P2pConnectionResponse::Rejected with a RejectionReason
   • Error variants for decryption failures or internal errors
5. If accepted, both peers use the SDP data to establish the WebRTC connection
6. Connection authentication occurs using ConnectionAuth derived from SDP hashes

Security Features

• Chain ID Verification: Ensures peers are on the same blockchain network
• Identity Authentication: Uses public key cryptography to verify peer identity
• Encryption Support: Messages can be encrypted using EncryptedOffer and EncryptedAnswer
• Connection Authentication: SDP hashes used for secure handshake verification

Structs

Answer

WebRTC connection answer responding to an offer.

EncryptedAnswer

Encrypted WebRTC connection response for secure signaling.

EncryptedOffer

Encrypted WebRTC offer for secure signaling.

Offer

WebRTC connection offer containing SDP data and peer information.

Enums

P2pConnectionResponse

Response to a WebRTC connection offer.

RejectionReason

Reasons why a WebRTC connection offer might be rejected.

Signal

Union type for WebRTC signaling messages.

Functions

sdp_hash 🔒

Computes SHA-256 hash of SDP (Session Description Protocol) data.