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Firefox OS/Remote Control: Difference between revisions
→Architecture Designs: Add notices of data encryption/decryption
(→Control event processing: Add steps of control event processing) |
(→Architecture Designs: Add notices of data encryption/decryption) |
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# Client.sjs decrypts event with symmetric key received in establish secure connection. | # Client.sjs decrypts event with symmetric key received in establish secure connection. | ||
# Client.sjs parses event and dispatch to Gecko or Gaia system app. | # Client.sjs parses event and dispatch to Gecko or Gaia system app. | ||
=== Data encryption/decryption === | |||
There are three kinds of data are encrypted while tranmission: | |||
# Client polls '''UUID''' in establish secure connection stage | |||
# Client sends '''PIN code''' in pin code pairing | |||
# Client sends '''event''' in control event processing | |||
As data are encrypted by symmetric key, AES-GCM, there are two things need noticed: | |||
# AES-GCM need initialization vector(IV) to encrypt/decrypt. Currently, IV is random value for each data, length is 12 bytes. Encrypted data is appended after IV. Receiver needs to slice first 12 bytes as IV to decrypt. | |||
# Each message type is string, use [https://developer.mozilla.org/en-US/docs/Web/API/TextEncoder/encode TextEncoder.encode()] to encode as an UInt8Array, then encrypt to ArrayBuffer. Vice versa. | |||
# Data encryption/decryption is asynchronous but HTTP request need response immediately. For UUID and PIN code case, remote control uses a ticket number to get status after decryption. But for event, we reduce polling result but use latest event's result instead. | |||
=== Ajax Protocol === | === Ajax Protocol === | ||