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'] }).sort
  checksum = Digest::MD5.hexdigest session_ids.join

  {
    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(&->(s) { { session_id: s } }),
    silent: false
  }.compact
end

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



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 156

def decrypt_message(data, sk: nil, si: nil)
  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)...(bytes.size - 16)].pack('C*'))
  decrypter.final

  Base64.urlsafe_encode64 decrypted
end

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

Raises:



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# File 'lib/mixin_bot/api/encrypted_message.rb', line 113

def encrypt_message(data, sessions = [], sk: nil, pk: nil)
  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...]

  Digest::MD5.hexdigest sessions.map(&->(s) { s['session_id'] }).sort.join
  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 += [sessions.size].pack('v*').bytes
  bytes += 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 += (MixinBot::UUID.new(hex: session['session_id']).packed + iv).bytes
    bytes += encrypter.update(key + padtext).bytes
  end

  bytes += nounce.bytes
  bytes += 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_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

#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 105

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 100

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