hyper-social / hyper-social-web / lib / post-signer.js

/**
 * Post signing for hyper-social-web
 *
 * Signs outgoing posts with ANProto content-signing (Wiredove-compatible).
 * Server-side verification of incoming signed posts.
 */

import { ANProto } from 'hyper-identity'

/**
 * Sign a post's content with ANProto
 *
 * @param {string} text - Post text
 * @param {{ publicKey: Buffer, secretKey: Buffer }} keypair - Server or user keypair
 * @returns {{ anproto: string, hash: string }}
 */
export function signPost (text, keypair) {
  const hash = ANProto.hash(text)
  const anproto = ANProto.signContent(hash, keypair)
  return { anproto, hash }
}

/**
 * Verify a signed post
 *
 * @param {{ text: string, anproto: string }} post
 * @returns {{ verified: boolean, author: string, timestamp: number } | { verified: false }}
 */
export function verifyPost (post) {
  if (!post || !post.anproto) {
    return { verified: false }
  }

  try {
    const opened = ANProto.open(post.anproto)
    const expectedHash = ANProto.hash(post.text)

    if (opened.hash !== expectedHash) {
      return { verified: false }
    }

    return {
      verified: true,
      author: opened.publicKey,
      timestamp: opened.timestamp
    }
  } catch {
    return { verified: false }
  }
}