Host Proof Transcript Builder (src/host-proof-transcript.ts)

Builds canonical binary transcripts and challenge plaintexts for relay host authentication proofs using domain-separated encoding for HMAC/box crypto.

// Source: https://github.com/stablyai/orca | License: MIT | Copyright 2026 Lovecast Inc
// Provided via justclaw.it.com; keep this notice with the code.
const textEncoder = new TextEncoder()

export const HOST_PROOF_TRANSCRIPT_DOMAIN = 'orca-relay-host-proof/v1'
export const HOST_CHALLENGE_PLAINTEXT_DOMAIN = 'orca-relay-host-challenge/v1'
export const HOST_CHALLENGE_BOX_ALGORITHM = 'Curve25519-XSalsa20-Poly1305'
export const HOST_PROOF_ALGORITHM = 'HMAC-SHA-256'

export interface HostProofTranscriptInput {
  relayOrigin: string
  relayEphemeralPublicKey: Uint8Array
  challengeNonce: Uint8Array
  challengeId: string
  issuedAt: number
  expiresAt: number
  userId: string
  profileId: string
  organizationId: string
  relayHostId: string
  hostPublicKey: Uint8Array
  assignmentEpoch: number

... (truncated -- full source via MCP)