Authentication is reading 2 bytes at a time

[bdraco]

connect(48, {sa_family=AF_UNIX, sun_path="/var/run/dbus/system_bus_socket"}, 34) = 0
ioctl(48, FIONBIO, [1])                 = 0
getpid()                                = 61
sendto(48, "\0", 1, 0, NULL, 0)         = 1
getuid()                                = 0
sendto(48, "AUTH EXTERNAL 30\r\n", 18, 0, NULL, 0) = 18
recvfrom(48, "OK", 2, 0, NULL, NULL)    = 2
recvfrom(48, " 2", 2, 0, NULL, NULL)    = 2
recvfrom(48, "7e", 2, 0, NULL, NULL)    = 2
recvfrom(48, "cd", 2, 0, NULL, NULL)    = 2
recvfrom(48, "1c", 2, 0, NULL, NULL)    = 2
recvfrom(48, "33", 2, 0, NULL, NULL)    = 2
recvfrom(48, "de", 2, 0, NULL, NULL)    = 2
recvfrom(48, "69", 2, 0, NULL, NULL)    = 2
recvfrom(48, "bc", 2, 0, NULL, NULL)    = 2
recvfrom(48, "a6", 2, 0, NULL, NULL)    = 2
recvfrom(48, "1b", 2, 0, NULL, NULL)    = 2
recvfrom(48, "ca", 2, 0, NULL, NULL)    = 2
recvfrom(48, "f9", 2, 0, NULL, NULL)    = 2
recvfrom(48, "1b", 2, 0, NULL, NULL)    = 2
recvfrom(48, "e3", 2, 0, NULL, NULL)    = 2
recvfrom(48, "76", 2, 0, NULL, NULL)    = 2
recvfrom(48, "fc", 2, 0, NULL, NULL)    = 2
recvfrom(48, "6\r", 2, 0, NULL, NULL)   = 2
recvfrom(48, "\n", 2, 0, NULL, NULL)    = 1
sendto(48, "NEGOTIATE_UNIX_FD\r\n", 19, 0, NULL, 0) = 19
recvfrom(48, "AG", 2, 0, NULL, NULL)    = 2
recvfrom(48, "RE", 2, 0, NULL, NULL)    = 2
recvfrom(48, "E_", 2, 0, NULL, NULL)    = 2
recvfrom(48, "UN", 2, 0, NULL, NULL)    = 2
recvfrom(48, "IX", 2, 0, NULL, NULL)    = 2
recvfrom(48, "_F", 2, 0, NULL, NULL)    = 2
recvfrom(48, "D\r", 2, 0, NULL, NULL)   = 2
recvfrom(48, "\n", 2, 0, NULL, NULL)    = 1
sendto(48, "BEGIN\r\n", 7, 0, NULL, 0)  = 7

[bdraco]

    async def _auth_readline(self) -> str:
        buf = b""
        while buf[-2:] != b"\r\n":
            buf += await self._loop.sock_recv(self._sock, 2)
        return buf[:-2].decode()

[bdraco]

we can actually mis align the buffer here since we should only read up to 1 if we have b"BEGIN\r"

[bdraco]

So we should read 1024, and then when we expect BEGIN\r\n we need to only read the missing bytes