try: import uselect import ussl import io import ubinascii as binascii except ImportError: print("SKIP") raise SystemExit from micropython import const _MP_STREAM_POLL_RD = const(0x0001) _MP_STREAM_POLL_WR = const(0x0004) _MP_STREAM_POLL_NVAL = const(0x0020) _MP_STREAM_POLL = const(3) _MP_STREAM_CLOSE = const(4) # This self-signed key/cert pair is randomly generated and to be used for # testing/demonstration only. You should always generate your own key/cert. key = binascii.unhexlify( b"3082013b020100024100cc20643fd3d9c21a0acba4f48f61aadd675f52175a9dcf07fbef" b"610a6a6ba14abb891745cd18a1d4c056580d8ff1a639460f867013c8391cdc9f2e573b0f" b"872d0203010001024100bb17a54aeb3dd7ae4edec05e775ca9632cf02d29c2a089b563b0" b"d05cdf95aeca507de674553f28b4eadaca82d5549a86058f9996b07768686a5b02cb240d" b"d9f1022100f4a63f5549e817547dca97b5c658038e8593cb78c5aba3c4642cc4cd031d86" b"8f022100d598d870ffe4a34df8de57047a50b97b71f4d23e323f527837c9edae88c79483" b"02210098560c89a70385c36eb07fd7083235c4c1184e525d838aedf7128958bedfdbb102" b"2051c0dab7057a8176ca966f3feb81123d4974a733df0f958525f547dfd1c271f9022044" b"6c2cafad455a671a8cf398e642e1be3b18a3d3aec2e67a9478f83c964c4f1f" ) cert = binascii.unhexlify( b"308201d53082017f020203e8300d06092a864886f70d01010505003075310b3009060355" b"0406130258583114301206035504080c0b54686550726f76696e63653110300e06035504" b"070c075468654369747931133011060355040a0c0a436f6d70616e7958595a3113301106" b"0355040b0c0a436f6d70616e7958595a3114301206035504030c0b546865486f73744e61" b"6d65301e170d3139313231383033333935355a170d3239313231353033333935355a3075" b"310b30090603550406130258583114301206035504080c0b54686550726f76696e636531" b"10300e06035504070c075468654369747931133011060355040a0c0a436f6d70616e7958" b"595a31133011060355040b0c0a436f6d70616e7958595a3114301206035504030c0b5468" b"65486f73744e616d65305c300d06092a864886f70d0101010500034b003048024100cc20" b"643fd3d9c21a0acba4f48f61aadd675f52175a9dcf07fbef610a6a6ba14abb891745cd18" b"a1d4c056580d8ff1a639460f867013c8391cdc9f2e573b0f872d0203010001300d06092a" b"864886f70d0101050500034100b0513fe2829e9ecbe55b6dd14c0ede7502bde5d46153c8" b"e960ae3ebc247371b525caeb41bbcf34686015a44c50d226e66aef0a97a63874ca5944ef" b"979b57f0b3" ) class _Pipe(io.IOBase): def __init__(self): self._other = None self.block_reads = False self.block_writes = False self.write_buffers = [] self.last_poll_arg = None def readinto(self, buf): if self.block_reads or len(self._other.write_buffers) == 0: return None read_buf = self._other.write_buffers[0] l = min(len(buf), len(read_buf)) buf[:l] = read_buf[:l] if l == len(read_buf): self._other.write_buffers.pop(0) else: self._other.write_buffers[0] = read_buf[l:] return l def write(self, buf): if self.block_writes: return None self.write_buffers.append(memoryview(bytes(buf))) return len(buf) def ioctl(self, request, arg): if request == _MP_STREAM_POLL: self.last_poll_arg = arg ret = 0 if arg & _MP_STREAM_POLL_RD: if not self.block_reads and self._other.write_buffers: ret |= _MP_STREAM_POLL_RD if arg & _MP_STREAM_POLL_WR: if not self.block_writes: ret |= _MP_STREAM_POLL_WR return ret elif request == _MP_STREAM_CLOSE: return 0 raise NotImplementedError() @classmethod def new_pair(cls): p1 = cls() p2 = cls() p1._other = p2 p2._other = p1 return p1, p2 def assert_poll(s, i, arg, expected_arg, expected_ret): ret = s.ioctl(_MP_STREAM_POLL, arg) assert i.last_poll_arg == expected_arg i.last_poll_arg = None assert ret == expected_ret def assert_raises(cb, *args, **kwargs): try: cb(*args, **kwargs) raise AssertionError("should have raised") except Exception as exc: pass client_io, server_io = _Pipe.new_pair() client_io.block_reads = True client_io.block_writes = True client_sock = ussl.wrap_socket(client_io, do_handshake=False) server_sock = ussl.wrap_socket(server_io, key=key, cert=cert, server_side=True, do_handshake=False) # Do a test read, at this point the TLS handshake wants to write, # so it returns None: assert client_sock.read(128) is None # Polling for either read or write actually check if the underlying socket can write: assert_poll(client_sock, client_io, _MP_STREAM_POLL_RD, _MP_STREAM_POLL_WR, 0) assert_poll(client_sock, client_io, _MP_STREAM_POLL_WR, _MP_STREAM_POLL_WR, 0) # Mark the socket as writable, and do another test read: client_io.block_writes = False assert client_sock.read(128) is None # The client wrote the CLIENT_HELLO message assert len(client_io.write_buffers) == 1 # At this point the TLS handshake wants to read, but we don't know that yet: assert_poll(client_sock, client_io, _MP_STREAM_POLL_RD, _MP_STREAM_POLL_RD, 0) assert_poll(client_sock, client_io, _MP_STREAM_POLL_WR, _MP_STREAM_POLL_WR, _MP_STREAM_POLL_WR) # Do a test write client_sock.write(b"foo") # Now we know that we want to read: assert_poll(client_sock, client_io, _MP_STREAM_POLL_RD, _MP_STREAM_POLL_RD, 0) assert_poll(client_sock, client_io, _MP_STREAM_POLL_WR, _MP_STREAM_POLL_RD, 0) # Unblock reads and nudge the two sockets: client_io.block_reads = False while server_io.write_buffers or client_io.write_buffers: if server_io.write_buffers: assert client_sock.read(128) is None if client_io.write_buffers: assert server_sock.read(128) is None # At this point, the handshake is done, try writing data: client_sock.write(b"foo") assert server_sock.read(3) == b"foo" # Test reading partial data: client_sock.write(b"foobar") assert server_sock.read(3) == b"foo" server_io.block_reads = True assert_poll( server_sock, server_io, _MP_STREAM_POLL_RD, None, _MP_STREAM_POLL_RD ) # Did not go to the socket, just consumed buffered data assert server_sock.read(3) == b"bar" # Polling on a closed socket errors out: client_io, _ = _Pipe.new_pair() client_sock = ussl.wrap_socket(client_io, do_handshake=False) client_sock.close() assert_poll( client_sock, client_io, _MP_STREAM_POLL_RD, None, _MP_STREAM_POLL_NVAL ) # Did not go to the socket # Errors propagates to poll: client_io, server_io = _Pipe.new_pair() client_sock = ussl.wrap_socket(client_io, do_handshake=False) # The server returns garbage: server_io.write(b"fooba") # Needs to be exactly 5 bytes assert_poll(client_sock, client_io, _MP_STREAM_POLL_RD, _MP_STREAM_POLL_RD, _MP_STREAM_POLL_RD) assert_raises(client_sock.read, 128) assert_poll( client_sock, client_io, _MP_STREAM_POLL_RD, None, _MP_STREAM_POLL_NVAL ) # Did not go to the socket