implement axolotl support

[pravi]

There is a similar proposal for google summer code for conversations android app. http://wiki.xmpp.org/web/Summer_of_Code_2015#axolotl_support_for_Conversations

There is already a javascript implementation of the protocol https://github.com/joebandenburg/libaxolotl-javascript

Without this support xmpp is not usable in an unreliable network, like we have in India or most developing countries that Firefox OS is targetting. This support would make xmpp a usable alternative to whatsapp.

[aesedepece]

👍 , this is a must have.
Meanwhile, we have OTR which is a widely adopted solution in the XMPP ecosystem.

[pravi]

OTR does not work well when connection breaks often, which is the case most of the time where I live. Also it needs both to be online to start. Most people use WhatsApp as a cheaper alternative to SMS. We don't have any reliable Free Software that does asynchronous end to end encrypted messages for Firefox OS. TextSecure or XMPP with axolotl would be a big boost to Firefox OS.

[TitanNano]

this is XMPP only, right?

[aesedepece]

@TitanNano Axolotl is used in WhatsApp as well.

[TitanNano]

Do we want to replace OTR with axolotl or do we want to support both?

[pravi]

I think axolotl is not yet widely available in other clients. So providing both until other clients catch up would be good.

[argon-radio]

I dont use loqui so far (ubuntu touch), but it would be better to support both OTR and axolotl, as pravi said, but keep them even if axolotl is more popular.

[acidicX]

Supporting both should definitely be good, OTR has auto-discovery for clients that support it. Is that the case with axolotl over XMPP? That should make things easier in the UI.

[TitanNano]

yes that's actually what I have in mind. try to go with axolotl and if the other client doesn't support it, try to fall back on OTR.

[pravi]

You can follow the work on axolotr support in "conversations" android app here http://conversationsgsoc2015.blogspot.fr/ He mentions some of the design decisions and challenges, it would be good to collaborate.

[pravi]

This has landed in conversations 1.6.0 today (its called omemo). They are drafting an xep right now.

[cmeerw]

Just in case anyone is interested... :-)

<message from="447961596923@s.whatsapp.net" type="text" id="1455740795-6" t="1455740796" notify="447961596923">
<enc type="pkmsg" v="1">
...</enc>
</message>
 ~ BinaryReader.prototype._readNextTree@app://750a5242-8bff-4e0d-a050-3684fd86ed3d/scripts/mozillahispano/coseme.js:5367:7 [BinaryReader] tools.js:17:6
Parsing message: {"_tag":"message","children":[{"_tag":"enc","children":[],"attributes":{"type":"pkmsg","v":"1"},"_data":{"hexdata":"3308bcc9c102122105185b8d1c94b6ed83f0220e6acb678e6262d0ca9093d5df77d10421fea537ab541a21050cc2ec8a26842c90da1bc641dba65023d536cf11685523f0499caf0393394c722242330a2105939b8dbd79bedec159f7230c2059f4c7567b3ed3f787d6beeb97adeec379d11010001800221070726ecfbfc610d678b5bbe188406582ab92d75ef4f5bbdd28f5d6b2a70430d0e0a302"}}],"attributes":{"from":"447961596923@s.whatsapp.net","type":"text","id":{"hexdata":"313435353734303739352d36"},"t":"1455740796","notify":{"hexdata":"343437393631353936393233"}},"_data":null} ~ parseMessage@app://750a5242-8bff-4e0d-a050-3684fd86ed3d/scripts/mozillahispano/coseme.js:6997:5 [ReaderThread] tools.js:17:6
ENCRYPTED MESSAGE Uint8Array [ 51, 8, 188, 201, 193, 2, 18, 33, 5, 24, 145 more… ] tools.js:17:6
Write node called with  {"_tag":"receipt","children":[],"attributes":{"to":"447961596923@s.whatsapp.net","id":"1455740795-6","t":1455740796439},"_data":null} ~ self._writeNode@app://750a5242-8bff-4e0d-a050-3684fd86ed3d/scripts/mozillahispano/coseme.js:7748:7 [ConnectionManager] tools.js:17:6
Expecting a string! number given instead. ~ BinaryWriter.prototype.writeString@app://750a5242-8bff-4e0d-a050-3684fd86ed3d/scripts/mozillahispano/coseme.js:4911:1 [BinaryWriter] tools.js:17:6
<receipt to="447961596923@s.whatsapp.net" id="1455740795-6" t="1455740796439">
</receipt>
 ~ BinaryWriter.prototype._write@app://750a5242-8bff-4e0d-a050-3684fd86ed3d/scripts/mozillahispano/coseme.js:4835:1 [BinaryWriter] tools.js:17:6
getLocalIdentityKeyPair coseme.js:88:4
getLocalRegistrationId coseme.js:92:4
SESSION CREATED Object { states: Array[1], 1 more… } tools.js:17:6
getLocalSignedPreKeyPair 4780112 coseme.js:96:4
getLocalPreKeyPair 5268668 coseme.js:101:4
getLocalIdentityKeyPair coseme.js:88:4
DECRYPTED MESSAGE Hello, world Object { message: ArrayBuffer, session: Object, identityKey: ArrayBuffer, registrationId: 1156361077 } tools.js:17:6
MESSAGE 1455740795-6 447961596923@s.whatsapp.net Hello, world 1455740796 false 447961596923 false tools.js:17:6
RECEIVE Hello, world Object {  } tools.js:17:6

There is still a lot of work to do, but seems ok for a proof of concept.

[TitanNano]

@cmeerw this is great! 👍

[cmeerw]

I have committed some support for axolotl encryption in #950 - this supports both encryption and decryption of version 1 messages (version 2 is not supported yet, but shouldn't be too difficult to add). It also doesn't support any media encryption or encrypted group chats (supporting encrypted group chats is probably the most difficult outstanding issue).
Note that it also won't work on older Firefox OS releases (currently, it will just fail there - need to at least fall back to plaintext there)