[Iran] Using Champa proxy

Champa implements adaptive request-rate control: when the AMP cache returns an unexpected response (e.g., HTTP 302), the client halves its polling rate. Once the polling interval exceeds one second the client is considered fully rate-limited and must restart after a multi-hour cooldown. This mechanism keeps the client from burning through its allowance when cache responses degrade.

Troubleshooting section defense throttling ir

Champa's AMP-cache tunnel delivers at most ~15 KB/s throughput before AMP rate-limiting activates. Sessions last approximately 15 minutes before the rate limit triggers; after that, users must stop the client and wait several hours before resuming.

Issue body (rate-limit description) evaluation throttling ir

As of June 2025, Iran blocks GitHub.com and Telegram but leaves the IP address of google.com reachable and Google Drive accessible. This selective blocking pattern created the operational window for Champa: because google.com is reachable, its AMP cache (cdn.ampproject.org) can be reached by fronting on that IP, then used to proxy connections to otherwise-blocked destinations.

Issue body (opening description) deployment ip-blockingdns-poisoning ir

Because GitHub is blocked in Iran, Champa distributes binaries through three alternative channels: a Telegram bot (@getchampabot), Google Drive folders, and curl commands documented in the GitHub issue thread itself. The issue thread remains accessible via Google cache / AMP even when GitHub's domain is blocked, creating a bootstrapping loop.

Download section (§1) deployment ip-blocking ir

Champa routes connections by specifying an AMP cache URL (https://cdn.ampproject.org/) with google.com as the front domain, then uses the SOCKS5 proxy interface locally. The server's public key is hardcoded in the connection string, providing a fixed authentication token that prevents trivial impersonation of the proxy by a censor injecting a fake server response during active probing.

Setup section (§2) defense active-probingdpi ir