on fill server OTKs up to max/2
so we don't remove keys for yet to be received olm messages that claimed a key
This commit is contained in:
parent
0b211e8e1c
commit
8cd6a7988a
1 changed files with 36 additions and 15 deletions
|
@ -117,31 +117,52 @@ export class Account {
|
||||||
}
|
}
|
||||||
|
|
||||||
async generateOTKsIfNeeded(storage, log) {
|
async generateOTKsIfNeeded(storage, log) {
|
||||||
|
// We need to keep a pool of one time public keys on the server so that
|
||||||
|
// other devices can start conversations with us. But we can only store
|
||||||
|
// a finite number of private keys in the olm Account object.
|
||||||
|
// To complicate things further then can be a delay between a device
|
||||||
|
// claiming a public one time key from the server and it sending us a
|
||||||
|
// message. We need to keep the corresponding private key locally until
|
||||||
|
// we receive the message.
|
||||||
|
// But that message might never arrive leaving us stuck with duff
|
||||||
|
// private keys clogging up our local storage.
|
||||||
|
// So we need some kind of engineering compromise to balance all of
|
||||||
|
// these factors.
|
||||||
|
|
||||||
|
// Check how many keys we can store in the Account object.
|
||||||
const maxOTKs = this._account.max_number_of_one_time_keys();
|
const maxOTKs = this._account.max_number_of_one_time_keys();
|
||||||
const limit = maxOTKs / 2;
|
// Try to keep at most half that number on the server. This leaves the
|
||||||
if (this._serverOTKCount < limit) {
|
// rest of the slots free to hold keys that have been claimed from the
|
||||||
// TODO: cache unpublishedOTKCount, so we don't have to parse this JSON on every sync iteration
|
// server but we haven't recevied a message for.
|
||||||
// for now, we only determine it when serverOTKCount is sufficiently low, which is should rarely be,
|
// If we run out of slots when generating new keys then olm will
|
||||||
// and recheck
|
// discard the oldest private keys first. This will eventually clean
|
||||||
|
// out stale private keys that won't receive a message.
|
||||||
|
const keyLimit = Math.floor(maxOTKs / 2);
|
||||||
|
// does the server have insufficient OTKs?
|
||||||
|
if (this._serverOTKCount < keyLimit) {
|
||||||
const oneTimeKeys = JSON.parse(this._account.one_time_keys());
|
const oneTimeKeys = JSON.parse(this._account.one_time_keys());
|
||||||
const oneTimeKeysEntries = Object.entries(oneTimeKeys.curve25519);
|
const oneTimeKeysEntries = Object.entries(oneTimeKeys.curve25519);
|
||||||
const unpublishedOTKCount = oneTimeKeysEntries.length;
|
const unpublishedOTKCount = oneTimeKeysEntries.length;
|
||||||
const totalOTKCount = this._serverOTKCount + unpublishedOTKCount;
|
// we want to end up with maxOTKs / 2 key on the server,
|
||||||
if (totalOTKCount < limit) {
|
// so generate any on top of the remaining ones on the server and the unpublished ones
|
||||||
// we could in theory also generated the keys and store them in
|
// (we have generated before but haven't uploaded yet for some reason)
|
||||||
// writeSync, but then we would have to clone the account to avoid side-effects.
|
// to get to that number.
|
||||||
await log.wrap("generate otks", log => this._updateSessionStorage(storage, sessionStore => {
|
const newKeyCount = keyLimit - unpublishedOTKCount - this._serverOTKCount;
|
||||||
const newKeyCount = maxOTKs - totalOTKCount;
|
if (newKeyCount > 0) {
|
||||||
|
await log.wrap("generate otks", log => {
|
||||||
log.set("max", maxOTKs);
|
log.set("max", maxOTKs);
|
||||||
log.set("server", this._serverOTKCount);
|
log.set("server", this._serverOTKCount);
|
||||||
log.set("unpublished", unpublishedOTKCount);
|
log.set("unpublished", unpublishedOTKCount);
|
||||||
log.set("new", newKeyCount);
|
log.set("new", newKeyCount);
|
||||||
log.set("limit", limit);
|
log.set("limit", keyLimit);
|
||||||
this._account.generate_one_time_keys(newKeyCount);
|
this._account.generate_one_time_keys(newKeyCount);
|
||||||
sessionStore.set(ACCOUNT_SESSION_KEY, this._account.pickle(this._pickleKey));
|
this._updateSessionStorage(storage, sessionStore => {
|
||||||
}));
|
sessionStore.set(ACCOUNT_SESSION_KEY, this._account.pickle(this._pickleKey));
|
||||||
return true;
|
});
|
||||||
|
});
|
||||||
}
|
}
|
||||||
|
// even though we didn't generate any keys, we still have some unpublished ones that should be published
|
||||||
|
return true;
|
||||||
}
|
}
|
||||||
return false;
|
return false;
|
||||||
}
|
}
|
||||||
|
|
Reference in a new issue