inputmice / xeps Goto Github PK

It is unclear how the PreKeyWhisperMessage is marshaled and handled within the OMEMO XEP. For example:

If such an element exists, the client checks whether the element's contents are a PreKeyWhisperMessage.

How does one perform this check?

I'm quite confused about the data that is pushed to the 'urn:xmpp:omemo:0:bundles:1234' node.

• Why is there one <signedPreKeyPublic> element? What is this key for? Are the other 100 <preKeyPublic> PreKeys not signed?
• What key is used to sign that PreKey? So far, only a Curve25519 key has been created, which is a ECDH curve.

As each PreKey can only be used once, the party that sends their initial PreKeyWhisperMessage later loses this race condition.

• Why can a PreKey only be used once? As far as I understand, it only weakens the forward-secrecy to reuse a PreKey (compromising the private key of that PreKey could allow decrypting two sessions instead of one). But if the damage has already been done and it has been used by two contacts, why not use the key? Of course it should be erased as soon as possible, but I think it would be fine to delay that until MAM has caught up.

The terms are, as far as I can tell, not explained in the XEP. I assume 'rid' stands for "remote (device) id"?