shell bypass 403
import io
import socket
import ssl
from urllib3.exceptions import ProxySchemeUnsupported
from urllib3.packages import six
SSL_BLOCKSIZE = 16384
class SSLTransport:
"""
The SSLTransport wraps an existing socket and establishes an SSL connection.
Contrary to Python's implementation of SSLSocket, it allows you to chain
multiple TLS connections together. It's particularly useful if you need to
implement TLS within TLS.
The class supports most of the socket API operations.
"""
@staticmethod
def _validate_ssl_context_for_tls_in_tls(ssl_context):
"""
Raises a ProxySchemeUnsupported if the provided ssl_context can't be used
for TLS in TLS.
The only requirement is that the ssl_context provides the 'wrap_bio'
methods.
"""
if not hasattr(ssl_context, "wrap_bio"):
if six.PY2:
raise ProxySchemeUnsupported(
"TLS in TLS requires SSLContext.wrap_bio() which isn't "
"supported on Python 2"
)
else:
raise ProxySchemeUnsupported(
"TLS in TLS requires SSLContext.wrap_bio() which isn't "
"available on non-native SSLContext"
)
def __init__(
self, socket, ssl_context, server_hostname=None, suppress_ragged_eofs=True
):
"""
Create an SSLTransport around socket using the provided ssl_context.
"""
self.incoming = ssl.MemoryBIO()
self.outgoing = ssl.MemoryBIO()
self.suppress_ragged_eofs = suppress_ragged_eofs
self.socket = socket
self.sslobj = ssl_context.wrap_bio(
self.incoming, self.outgoing, server_hostname=server_hostname
)
# Perform initial handshake.
self._ssl_io_loop(self.sslobj.do_handshake)
def __enter__(self):
return self
def __exit__(self, *_):
self.close()
def fileno(self):
return self.socket.fileno()
def read(self, len=1024, buffer=None):
return self._wrap_ssl_read(len, buffer)
def recv(self, len=1024, flags=0):
if flags != 0:
raise ValueError("non-zero flags not allowed in calls to recv")
return self._wrap_ssl_read(len)
def recv_into(self, buffer, nbytes=None, flags=0):
if flags != 0:
raise ValueError("non-zero flags not allowed in calls to recv_into")
if buffer and (nbytes is None):
nbytes = len(buffer)
elif nbytes is None:
nbytes = 1024
return self.read(nbytes, buffer)
def sendall(self, data, flags=0):
if flags != 0:
raise ValueError("non-zero flags not allowed in calls to sendall")
count = 0
with memoryview(data) as view, view.cast("B") as byte_view:
amount = len(byte_view)
while count < amount:
v = self.send(byte_view[count:])
count += v
def send(self, data, flags=0):
if flags != 0:
raise ValueError("non-zero flags not allowed in calls to send")
response = self._ssl_io_loop(self.sslobj.write, data)
return response
def makefile(
self, mode="r", buffering=None, encoding=None, errors=None, newline=None
):
"""
Python's httpclient uses makefile and buffered io when reading HTTP
messages and we need to support it.
This is unfortunately a copy and paste of socket.py makefile with small
changes to point to the socket directly.
"""
if not set(mode) <= {"r", "w", "b"}:
raise ValueError("invalid mode %r (only r, w, b allowed)" % (mode,))
writing = "w" in mode
reading = "r" in mode or not writing
assert reading or writing
binary = "b" in mode
rawmode = ""
if reading:
rawmode += "r"
if writing:
rawmode += "w"
raw = socket.SocketIO(self, rawmode)
self.socket._io_refs += 1
if buffering is None:
buffering = -1
if buffering < 0:
buffering = io.DEFAULT_BUFFER_SIZE
if buffering == 0:
if not binary:
raise ValueError("unbuffered streams must be binary")
return raw
if reading and writing:
buffer = io.BufferedRWPair(raw, raw, buffering)
elif reading:
buffer = io.BufferedReader(raw, buffering)
else:
assert writing
buffer = io.BufferedWriter(raw, buffering)
if binary:
return buffer
text = io.TextIOWrapper(buffer, encoding, errors, newline)
text.mode = mode
return text
def unwrap(self):
self._ssl_io_loop(self.sslobj.unwrap)
def close(self):
self.socket.close()
def getpeercert(self, binary_form=False):
return self.sslobj.getpeercert(binary_form)
def version(self):
return self.sslobj.version()
def cipher(self):
return self.sslobj.cipher()
def selected_alpn_protocol(self):
return self.sslobj.selected_alpn_protocol()
def selected_npn_protocol(self):
return self.sslobj.selected_npn_protocol()
def shared_ciphers(self):
return self.sslobj.shared_ciphers()
def compression(self):
return self.sslobj.compression()
def settimeout(self, value):
self.socket.settimeout(value)
def gettimeout(self):
return self.socket.gettimeout()
def _decref_socketios(self):
self.socket._decref_socketios()
def _wrap_ssl_read(self, len, buffer=None):
try:
return self._ssl_io_loop(self.sslobj.read, len, buffer)
except ssl.SSLError as e:
if e.errno == ssl.SSL_ERROR_EOF and self.suppress_ragged_eofs:
return 0 # eof, return 0.
else:
raise
def _ssl_io_loop(self, func, *args):
"""Performs an I/O loop between incoming/outgoing and the socket."""
should_loop = True
ret = None
while should_loop:
errno = None
try:
ret = func(*args)
except ssl.SSLError as e:
if e.errno not in (ssl.SSL_ERROR_WANT_READ, ssl.SSL_ERROR_WANT_WRITE):
# WANT_READ, and WANT_WRITE are expected, others are not.
raise e
errno = e.errno
buf = self.outgoing.read()
self.socket.sendall(buf)
if errno is None:
should_loop = False
elif errno == ssl.SSL_ERROR_WANT_READ:
buf = self.socket.recv(SSL_BLOCKSIZE)
if buf:
self.incoming.write(buf)
else:
self.incoming.write_eof()
return ret