h2_library_http2_get_request_with_ssl_alpn.py

1import socket
2import ssl
3
4import h2.connection
5import h2.events
6
7
8def get_response(url):
9    # Generic IPv4/TCP socket.
10    sock = socket.create_connection((url, 443))
11
12    # SSL context with ALPN for HTTP/2.
13    ctx = ssl.create_default_context()
14    ctx.set_alpn_protocols(['h2'])
15
16    sock = ctx.wrap_socket(sock, server_hostname=url)
17    assert sock.selected_alpn_protocol() == 'h2'
18
19    # Create h2 Connection and initiate it.
20    conn = h2.connection.H2Connection()
21    conn.initiate_connection()
22    sock.sendall(conn.data_to_send())
23
24    # Send a request!
25    headers = [
26        (':method', 'GET'),
27        (':path', '/'),
28        (':authority', url),
29        (':scheme', 'https'),
30    ]
31    conn.send_headers(1, headers, end_stream=True)
32    sock.sendall(conn.data_to_send())
33
34    while True:
35        data = sock.recv(65535)
36        if not data:
37            break
38
39        events = conn.receive_data(data)
40        for event in events:
41            if isinstance(event, h2.events.ResponseReceived):
42                print(f"Response headers: {event.headers}")
43            elif isinstance(event, h2.events.DataReceived):
44                # Update flow control window
45                conn.acknowledge_received_data(event.flow_controlled_length, event.stream_id)
46                print(f"Response data: {event.data}")
47            elif isinstance(event, h2.events.StreamEnded):
48                # Response complete
49                conn.close_connection()
50                sock.sendall(conn.data_to_send())
51                sock.close()
52                return
53
54        sock.sendall(conn.data_to_send())
55
56if __name__ == "__main__":
57    get_response('http2.akamai.com')