Most Onions Down due to a Denial of Service Attack on the Tor Network

Since yesterday due to a denial of service (DOS) on the Tor network most onions where down.

Most sdwdate onion time sources and SecureDrop onions didn’t work for me. The following references mention onion v3 only but most onions either v2 or v3 where inaccessible for me.

Quote Roger:

Hi folks,

The overload bugs on the directory authorities are continuing, but they
also continue to be mostly manageable.

But today, we spent several consensus intervals in a row without making
a consensus – which is supposed to be fine because Tor clients can do
fine so long as they have a consensus from within the last 24 hours,
but it exposed a bug in the v3 onion service implementation, where v3
onion clients and v3 onion services choose not to even attempt to fetch
or publish v3 onion descriptors:

Jan 10 11:32:24.364 [warn] No live consensus so we can’t get the
responsible hidden service directories.

The fix imo is that we need to make v3 onion services work under the
same time assumptions as the other parts of Tor – if you have a usable
consensus, then use it.

I’ve opened this ticket for the network team:
v3 onion services require a "live" consensus to publish or fetch (#40237) · Issues · The Tor Project / Core / Tor · GitLab


There also lots of reports by other users elsewhere on the internet on this issue of onion connectivity being broken generally.

Since sdwdate relies on Tor consensus (Tor Consensus Time Sanity Check) and fetches time from onions it can no longer fetch and update the system time.

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o Major bugfixes (onion service v3):
- Stop requiring a live consensus for v3 clients and services, and
allow a “reasonably live” consensus instead. This allows v3 onion
services to work even if the authorities fail to generate a
consensus for more than 2 hours in a row. Fixes bug 40237; bugfix

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