TESTING.md

Testing MTProxy

This repository includes a test suite to verify the functionality of the MTProxy server. The tests run in Docker or directly on the host and check:

1. HTTP Stats: Verifies the stats endpoint (port 8888) is accessible.
2. Prometheus Metrics: Verifies the /metrics endpoint returns valid Prometheus exposition format.
3. MTProto Port: Verifies the MTProto port accepts TCP connections.

Prerequisites

• Docker and Docker Compose (for containerized testing)
• make (for running the test command)
• Python 3.9+ (for local script execution without Docker)

Running Tests

Using Make (Docker)

Simply run:

make test

This will:

1. Build the MTProxy Docker image.
2. Build the test runner Docker image.
3. Start the proxy and test runner.
4. Execute the connectivity checks.

A random secret will be generated automatically if MTPROXY_SECRET is not set.

Running Locally (No Docker)

If you want to run the tests against a local instance:

1. Install Python dependencies:

   pip install -r tests/requirements.txt

2. Set environment variables:

   export MTPROXY_HOST=localhost  # or IP of your proxy
   export MTPROXY_PORT=443        # or your proxy port

3. Run the script:

   python3 tests/test_proxy.py

Manual Connectivity Check

If tests are failing, you can manually verify connectivity to Telegram servers:

# Check connectivity to Telegram DC 2 (Europe)
nc -zv 149.154.167.50 443
# Expected output: Connection to 149.154.167.50 443 port [tcp/https] succeeded!

If this fails, your network (ISP, firewall, or hosting provider) is blocking connections to Telegram.

Fuzz Testing

The fuzz/ directory contains libFuzzer harnesses for protocol parsers, compiled with AddressSanitizer and UndefinedBehaviorSanitizer.

Targets

Harness	Parser	What it tests
fuzz_tls_server_hello	tls_check_server_hello()	Extension parsing, length validation, record counting
fuzz_tls_client_hello	tls_parse_sni() + tls_parse_client_hello_ciphers()	SNI extraction, cipher suite GREASE skipping
fuzz_http_request	http_parse_data()	HTTP state machine, header limits, Content-Length overflow

Running

Requires Clang (for -fsanitize=fuzzer):

# Build fuzz targets
make fuzz CC=clang

# Run all targets for 60 seconds each (default)
make fuzz-run

# Custom duration
make fuzz-run FUZZ_DURATION=300

Seed corpus files are in fuzz/corpus/. The fuzzers also run automatically in CI on every push and PR.

Troubleshooting

• Timeout: If tests time out, check your network connection. MTProto proxies may be blocked by some ISPs.
• Port already in use: The tests use ports 18443 and 18888 by default. Make sure these are available.