Blocking of Snowflake in China, 2023-05-12 to 2023-05-15
Reports of failures to connect with Snowflake in China since 2023-05-12
https://github.com/net4people/bbs/issues/249
Around afternoon time on May 12 2023,tor browser's built in snowflake stops working
Connection asist doesn't work neither.In Wireshark I see full package loss(TCP Spurious Transmission) to the supposely existing bridge front server(i think that what it is called) ip after initial handshake.
https://forum.torproject.net/t/snowflake-bridge-does-not-work-in-china-since-days-ago/7635
I built the Snowflake client manually and run it, got Tor logs below, the connection hangs on 10% forever.
Bridge users graph.
A graph that shows the separate contributions of the two bridges, also with the ?? geolocation bug retroactively fixed, by redistributing ?? proportionally to the other countries. This was made from snowflake-graphs 9de9b4ed with the additional patch top-countries-cn.patch.gz.
Note that there are events from the the metrics timeline that bear on these graphs:
| start date | end date | places | protocols | description | links | ? |
|---|---|---|---|---|---|---|
| 2023-04-11 | cn | obfs4 | Sudden drop in access to bridges from the "settings" and "moat" pools from China. | comment bridge graph | X | |
| 2023-04-11 | snowflake | Release of Snowflake WebExtension 0.7.2, with a fix for missing client country information that had been introduced in 0.6.0 on 2022-06-27. The result is better country-level attribution of Snowflake users: most who had been being assigned to ?? are now assigned to their proper geolocated country. |
archive comment | |||
| 2023-04-12 | snowflake | Orbot begins a release rollout of version 17.0.0-RC-1-tor.0.4.7.11. First release of Orbot to include the snowflake-02 bridge along with the existing snowflake-01. Has a change to the Snowflake DTLS fingerprint (removes Hello Verify Request) to mitigate reported blocking in Russia. | release Orbot commit adding snowflake-02 IPtProxy commit upgrading Snowflake | |||
| 2023-04-19 | cn | obfs4 snowflake | Changed the recommended transport in Circumvention Settings in China from obfs4 to snowflake. | comment commit |
Relay users for comparison:
OONI's data on cdn.sstatic.net in China is sparse, though it perhaps shows a larger proportion of anomalies since 2023-05-12:
OONI has more torsf measurements. It does look like there are more anomalies since 2023-05-12, or even before.
