# Source code for imapclient.tls

    # Copyright (c) 2023, Menno Smits
    # Released subject to the New BSD License
    # Please see http://en.wikipedia.org/wiki/BSD_licenses

    """
    This module contains IMAPClient's functionality related to Transport
    Layer Security (TLS a.k.a. SSL).
    """

    import imaplib
    import io
    import socket
    import ssl
    from typing import Optional, TYPE_CHECKING

    if TYPE_CHECKING:
        from typing_extensions import Buffer

    def wrap_socket(
        sock: socket.socket, ssl_context: Optional[ssl.SSLContext], host: str
    ) -> socket.socket:
        if ssl_context is None:
            ssl_context = ssl.create_default_context(purpose=ssl.Purpose.SERVER_AUTH)

        return ssl_context.wrap_socket(sock, server_hostname=host)

    class IMAP4_TLS(imaplib.IMAP4):
        """IMAP4 client class for TLS/SSL connections.

        Adapted from imaplib.IMAP4_SSL.
        """

        def __init__(
            self,
            host: str,
            port: int,
            ssl_context: Optional[ssl.SSLContext],
            timeout: Optional[float] = None,
        ):
            self.ssl_context = ssl_context
            self._timeout = timeout
            imaplib.IMAP4.__init__(self, host, port)
            self.file: io.BufferedReader

        def open(
            self, host: str = "", port: int = 993, timeout: Optional[float] = None
        ) -> None:
            self.host = host
            self.port = port
            sock = socket.create_connection(
                (host, port), timeout if timeout is not None else self._timeout
            )
            self.sock = wrap_socket(sock, self.ssl_context, host)
            self.file = self.sock.makefile("rb")

        def read(self, size: int) -> bytes:
            return self.file.read(size)

        def readline(self) -> bytes:
            return self.file.readline()

        def send(self, data: "Buffer") -> None:
            self.sock.sendall(data)

        def shutdown(self) -> None:
            imaplib.IMAP4.shutdown(self)