Module: MixinBot::API::EncryptedMessage

Included in:
MixinBot::API
Defined in:
lib/mixin_bot/api/encrypted_message.rb

Instance Method Summary collapse

Instance Method Details

#base_encrypted_message_params(options) ⇒ Object

base format of message params



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 80

def base_encrypted_message_params(options)
  data = options[:data].is_a?(String) ? options[:data] : options[:data].to_json
  data_base64 = encrypt_message Base64.urlsafe_encode64(data, padding: false), options[:sessions]
  session_ids = options[:sessions].map { |s| s['session_id'] || s[:session_id] }.compact.sort
  checksum = MixinBot.utils.generate_user_checksum(options[:sessions])

  {
    conversation_id: options[:conversation_id],
    recipient_id: options[:recipient_id],
    representative_id: options[:representative_id],
    category: options[:category],
    quote_message_id: options[:quote_message_id],
    message_id: options[:message_id] || SecureRandom.uuid,
    data_base64:,
    checksum:,
    recipient_sessions: session_ids.map { |session_id| { session_id: } },
    # Go's MessageRequest always serializes `silent`; default stays false
    silent: (options[:silent] ? true : false)
  }.compact
end

#cached_encrypted_sessions(store, recipient_id) ⇒ Object

Read a recipient's sessions from the store. Stores that raise (a Redis outage) or return non-list values count as a cache miss, mirroring the Go SDK's if sessions, err := store.Get(...); err == nil tolerance.



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 189

def cached_encrypted_sessions(store, recipient_id)
  cached = begin
    # block form keeps 1-arity duck-typed stores (Hash included) working
    store.fetch(recipient_id) { nil } # rubocop:disable Style/RedundantFetchBlock
  rescue StandardError
    nil
  end

  sessions = Array(cached)
  return nil unless sessions.all?(Hash)
  return nil if sessions.empty?

  sessions.map(&:stringify_keys)
end

#decrypt_message(data, sk: nil, si: nil) ⇒ Object

rubocop:disable Naming/MethodParameterName



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 293

def decrypt_message(data, sk: nil, si: nil) # rubocop:disable Naming/MethodParameterName
  bytes = Base64.urlsafe_decode64(data).bytes

  si ||= config.session_id
  sk ||= config.session_private_key[0...32]

  size = 16 + 48
  return '' if bytes.size < 1 + 2 + 32 + size + 12

  session_length = bytes[1...3].pack('v*').unpack1('C*')
  prefix_size = 35 + (session_length * size)

  i = 35
  key = ''
  while i < prefix_size
    uuid = MixinBot::UUID.new(raw: bytes[i...(i + 16)].pack('C*')).unpacked
    if uuid == si
      pub = bytes[3...35]
      aes_key = JOSE::JWA::X25519.shared_secret(
        pub.pack('C*'),
        JOSE::JWA::Ed25519.secret_to_curve25519(sk)
      )
      iv = bytes[(i + 16)...(i + 16 + 16)].pack('C*')
      encrypted_key = bytes[(i + 16 + 16)...(i + size)].pack('C*')

      decrypter = OpenSSL::Cipher.new('AES-256-CBC').decrypt
      decrypter.iv = iv
      decrypter.key = aes_key
      cipher = decrypter.update(encrypted_key)
      key = cipher[...16]
      break
    end
    i += size
  end

  return '' unless key.size == 16

  decrypter = OpenSSL::Cipher.new('AES-128-GCM').decrypt
  decrypter.key = key
  decrypter.iv = bytes[prefix_size...(prefix_size + 12)].pack('C*')
  decrypter.auth_tag = bytes.last(16).pack('C*')
  decrypted = decrypter.update(bytes[(prefix_size + 12)...-16].pack('C*'))
  decrypter.final

  Base64.urlsafe_encode64 decrypted
end

#encrypt_message(data, sessions = [], sk: nil, pk: nil) ⇒ Object

rubocop:disable Naming/MethodParameterName

Raises:



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 251

def encrypt_message(data, sessions = [], sk: nil, pk: nil) # rubocop:disable Naming/MethodParameterName
  raise ArgumentError, 'Wrong sessions format!' unless sessions.all?(&->(s) { s.key?('session_id') && s.key?('public_key') })

  sk ||= config.session_private_key[0...32]
  pk ||= config.session_private_key[32...]

  encrypter = OpenSSL::Cipher.new('AES-128-GCM').encrypt
  key = encrypter.random_key
  nounce = encrypter.random_iv
  encrypter.key = key
  encrypter.iv = nounce
  encrypter.auth_data = ''
  ciphertext = encrypter.update(Base64.urlsafe_decode64(data)) + encrypter.final + encrypter.auth_tag

  bytes = [1]
  bytes.concat([sessions.size].pack('v*').bytes)
  bytes.concat(JOSE::JWA::Ed25519.pk_to_curve25519(pk).bytes)

  sessions.each do |session|
    aes_key = JOSE::JWA::X25519.shared_secret(
      Base64.urlsafe_decode64(session['public_key']),
      JOSE::JWA::Ed25519.secret_to_curve25519(sk)
    )

    padding = 16 - (key.size % 16)
    padtext = ([padding] * padding).pack('C*')

    encrypter = OpenSSL::Cipher.new('AES-256-CBC').encrypt
    encrypter.key = aes_key
    iv = encrypter.random_iv
    encrypter.iv = iv

    bytes.concat((MixinBot::UUID.new(hex: session['session_id']).packed + iv).bytes)
    bytes.concat(encrypter.update(key + padtext).bytes)
  end

  bytes.concat(nounce.bytes)
  bytes.concat(ciphertext.bytes)

  Base64.urlsafe_encode64 bytes.pack('C*'), padding: false
end

#encrypted_audio(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 36

def encrypted_audio(options)
  options.merge!(category: 'ENCRYPTED_AUDIO')
  base_encrypted_message_params(options)
end

#encrypted_contact(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 31

def encrypted_contact(options)
  options.merge!(category: 'ENCRYPTED_CONTACT')
  base_encrypted_message_params(options)
end

#encrypted_data(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 21

def encrypted_data(options)
  options.merge!(category: 'ENCRYPTED_DATA')
  base_encrypted_message_params(options)
end

#encrypted_image(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 16

def encrypted_image(options)
  options.merge!(category: 'ENCRYPTED_IMAGE')
  base_encrypted_message_params(options)
end

#encrypted_message_request(message, sessions) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 226

def encrypted_message_request(message, sessions)
  base_encrypted_message_params message.merge(sessions:, silent: (message[:silent] ? true : false))
end

#encrypted_message_results(messages, responses) ⇒ Object

Maps each pending message to its server response. Returns [results_by_message_id, failed_messages]; raises on malformed responses.



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 232

def encrypted_message_results(messages, responses)
  by_message_id = responses.to_h { |response| [response['message_id'], response] }

  results = {}
  failures = []
  messages.each do |message|
    response = by_message_id[message[:message_id]]
    raise ArgumentError, "encrypted message response missing for #{message[:message_id]}" if response.nil?

    results[message[:message_id]] = response
    case response['state']
    when 'SUCCESS' then nil
    when 'FAILED' then failures << message
    else raise ArgumentError, "encrypted message #{message[:message_id]} returned unknown state #{response['state']}"
    end
  end
  [results, failures]
end

#encrypted_post(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 11

def encrypted_post(options)
  options.merge!(category: 'ENCRYPTED_POST')
  base_encrypted_message_params(options)
end

#encrypted_sticker(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 26

def encrypted_sticker(options)
  options.merge!(category: 'ENCRYPTED_STICKER')
  base_encrypted_message_params(options)
end

#encrypted_text(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 6

def encrypted_text(options)
  options.merge!(category: 'ENCRYPTED_TEXT')
  base_encrypted_message_params(options)
end

#encrypted_video(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 41

def encrypted_video(options)
  options.merge!(category: 'ENCRYPTED_VIDEO')
  base_encrypted_message_params(options)
end

#fetch_encrypted_message_sessions!(recipient_ids, store, **kwargs) ⇒ Object

Fetch sessions for the given recipients and write them to the store. Returns { recipient_id => sessions } for the resolved recipients.



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 206

def fetch_encrypted_message_sessions!(recipient_ids, store, **kwargs)
  return {} if recipient_ids.empty?

  response = fetch_user_sessions(recipient_ids, **kwargs.slice(:access_token, :exp_in, :scp))
  grouped = {}
  Array(response['data']).each do |session|
    owner = session['user_id'].presence
    owner = recipient_ids.first if owner.blank? && recipient_ids.one?
    grouped[owner] = (grouped[owner] || []) + [session] if owner.present?
  end

  recipient_ids.each_with_object({}) do |recipient_id, resolved|
    sessions = grouped[recipient_id]
    raise ArgumentError, "no sessions found for recipient #{recipient_id}" if sessions.blank?

    store.store recipient_id, sessions.map(&:stringify_keys)
    resolved[recipient_id] = sessions.map(&:stringify_keys)
  end
end

#post_encrypted_messages(messages = nil, session_store: nil, **kwargs) ⇒ MixinBot::Models::ApiEnvelope

Encrypt and send messages using each recipient's current sessions.

Accepts a single options hash or an array of them (same shapes as send_encrypted_*_message). Sessions are resolved through the session store - session_store:, or the per-API-instance default store - and fetched via POST /sessions/fetch on a cache miss. Messages the server rejects because a recipient's sessions changed have their sessions evicted, refreshed, and are retried once. The returned envelope carries every message's final state (SUCCESS/FAILED).

Parameters:

  • messages (Hash, Array<Hash>) (defaults to: nil) —

    unencrypted message options

  • session_store (#fetch, #store) (defaults to: nil) —

    session cache; store(id, nil) evicts

Returns:

Raises:



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 129

def post_encrypted_messages(messages = nil, session_store: nil, **kwargs)
  messages = kwargs.delete(:messages) if messages.nil? && kwargs.key?(:messages)
  messages = [messages] unless messages.is_a? Array
  raise ArgumentError, 'messages must not be empty' if messages.empty?

  token_keys = %i[access_token exp_in scp]
  unknown = kwargs.keys - token_keys
  raise ArgumentError, "unsupported options: #{unknown.join(', ')}" if unknown.any?

  original = messages.map { |message| message.to_h.transform_keys(&:to_sym) }
  seen_ids = []
  pending = original.map do |message|
    raise ArgumentError, 'recipient_id is required' if message[:recipient_id].blank?
    if message[:message_id] && seen_ids.include?(message[:message_id])
      raise ArgumentError,
            "duplicate message_id #{message[:message_id]}"
    end

    message[:message_id] ||= SecureRandom.uuid
    seen_ids << message[:message_id]
    message
  end

  store = session_store || (@session_store ||= MixinBot::SessionStore.new)
  final_results = {}
  responses = nil

  2.times do |attempt|
    recipient_ids = pending.map { |message| message[:recipient_id] }.uniq
    missing = recipient_ids.reject { |recipient_id| cached_encrypted_sessions(store, recipient_id).present? }
    fetched = missing.any? ? fetch_encrypted_message_sessions!(missing, store, **kwargs) : {}

    requests = pending.map do |message|
      sessions = cached_encrypted_sessions(store, message[:recipient_id]) || fetched[message[:recipient_id]]
      raise ArgumentError, "no sessions found for recipient #{message[:recipient_id]}" if sessions.blank?

      encrypted_message_request(message, sessions)
    end
    responses = client.post '/encrypted_messages', *requests, **kwargs

    data = responses['data']
    data = [data] if data.is_a?(Hash)
    raise ArgumentError, 'unexpected /encrypted_messages response format' unless data.is_a? Array

    results, failures = encrypted_message_results(pending, data)
    final_results.merge!(results)
    break if failures.empty? || attempt.positive?

    pending = failures
    # the FAILED recipients' sessions are assumed expired: evict + refresh
    pending.map { |message| message[:recipient_id] }.uniq.each { |recipient_id| store.store recipient_id, nil }
  end

  responses.to_h['data'] = original.filter_map { |message| final_results[message[:message_id]] }
  responses
end

#send_encrypted_audio_message(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 71

def send_encrypted_audio_message(options)
  send_encrypted_message encrypted_audio(options)
end

#send_encrypted_contact_message(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 67

def send_encrypted_contact_message(options)
  send_encrypted_message encrypted_contact(options)
end

#send_encrypted_data_message(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 59

def send_encrypted_data_message(options)
  send_encrypted_message encrypted_data(options)
end

#send_encrypted_image_message(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 55

def send_encrypted_image_message(options)
  send_encrypted_message encrypted_image(options)
end

#send_encrypted_message(payload) ⇒ Object

http post request

Raises:



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 106

def send_encrypted_message(payload)
  path = '/encrypted_messages'
  payload = [payload] if payload.is_a? Hash
  raise ArgumentError, 'Wrong payload format!' unless payload.is_a? Array

  client.post path, *payload
end

#send_encrypted_messages(messages) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 101

def send_encrypted_messages(messages)
  send_encrypted_message messages
end

#send_encrypted_post_message(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 51

def send_encrypted_post_message(options)
  send_encrypted_message encrypted_post(options)
end

#send_encrypted_sticker_message(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 63

def send_encrypted_sticker_message(options)
  send_encrypted_message encrypted_sticker(options)
end

#send_encrypted_text_message(options) ⇒ Object

use HTTP to send message



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 47

def send_encrypted_text_message(options)
  send_encrypted_message encrypted_text(options)
end

#send_encrypted_video_message(options) ⇒ Object 



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 75

def send_encrypted_video_message(options)
  send_encrypted_message encrypted_video(options)
end