from __future__ import absolute_import
"""M2Crypto wrapper for OpenSSL BIO API.
Copyright (c) 1999-2004 Ng Pheng Siong. All rights reserved."""
import io
import logging
from typing import Any, AnyStr, Callable, Iterable, Optional, Union # noqa
from M2Crypto import m2
log = logging.getLogger('BIO')
[docs]
class BIOError(ValueError):
pass
m2.bio_init(BIOError)
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class BIO(object):
"""Abstract object interface to the BIO API."""
m2_bio_free = m2.bio_free
def __init__(self, bio=None, _pyfree=0, _close_cb=None):
# type: (Optional[BIO], int, Optional[Callable]) -> None
self.bio = bio
self._pyfree = _pyfree
self._close_cb = _close_cb
self.closed = 0
self.write_closed = 0
def __del__(self):
if self._pyfree:
self.m2_bio_free(self.bio)
def _ptr(self):
return self.bio
# Deprecated.
bio_ptr = _ptr
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def fileno(self):
# type: () -> int
return m2.bio_get_fd(self.bio)
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def readable(self):
# type: () -> bool
return not self.closed
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def read(self, size=None):
# type: (int) -> Union[bytes, bytearray]
if not self.readable():
raise IOError('cannot read')
if size is None:
buf = bytearray()
while 1:
data = m2.bio_read(self.bio, 4096)
if not data:
break
buf += data
return buf
elif size == 0:
return b''
elif size < 0:
raise ValueError('read count is negative')
else:
return bytes(m2.bio_read(self.bio, size))
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def readline(self, size=4096):
# type: (int) -> bytes
if not self.readable():
raise IOError('cannot read')
buf = m2.bio_gets(self.bio, size)
return '' if buf is None else buf
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def readlines(self, sizehint='ignored'):
# type: (Union[AnyStr, int]) -> Iterable[bytes]
if not self.readable():
raise IOError('cannot read')
lines = []
while 1:
buf = m2.bio_gets(self.bio, 4096)
if buf is None:
break
lines.append(buf)
return lines
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def writeable(self):
# type: () -> bool
return (not self.closed) and (not self.write_closed)
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def write(self, data):
# type: (AnyStr) -> int
"""Write data to BIO.
:return: either data written, or [0, -1] for nothing written,
-2 not implemented
"""
if not self.writeable():
raise IOError('cannot write')
if isinstance(data, str):
data = data.encode('utf8')
return m2.bio_write(self.bio, data)
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def write_close(self):
# type: () -> None
self.write_closed = 1
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def flush(self):
# type: () -> None
"""Flush the buffers.
:return: 1 for success, and 0 or -1 for failure
"""
m2.bio_flush(self.bio)
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def reset(self):
# type: () -> int
"""Set the bio to its initial state.
:return: 1 for success, and 0 or -1 for failure
"""
return m2.bio_reset(self.bio)
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def close(self):
# type: () -> None
self.closed = 1
if self._close_cb:
self._close_cb()
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def should_retry(self):
# type: () -> int
"""
Can the call be attempted again, or was there an error
ie do_handshake
"""
return m2.bio_should_retry(self.bio)
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def should_read(self):
# type: () -> int
"""Should we read more data?"""
return m2.bio_should_read(self.bio)
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def should_write(self):
# type: () -> int
"""Should we write more data?"""
return m2.bio_should_write(self.bio)
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def tell(self):
"""Return the current offset."""
return m2.bio_tell(self.bio)
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def seek(self, off):
"""Seek to the specified absolute offset."""
return m2.bio_seek(self.bio, off)
def __enter__(self):
return self
def __exit__(self, *args):
# type: (*Any) -> int
self.close()
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class MemoryBuffer(BIO):
"""Object interface to BIO_s_mem.
Empirical testing suggests that this class performs less well than
cStringIO, because cStringIO is implemented in C, whereas this class
is implemented in Python. Thus, the recommended practice is to use
cStringIO for regular work and convert said cStringIO object to
a MemoryBuffer object only when necessary.
"""
def __init__(self, data=None):
# type: (Optional[bytes]) -> None
super(MemoryBuffer, self).__init__(self)
if data is not None and not isinstance(data, bytes):
raise TypeError(
"data must be bytes or None, not %s" % (type(data).__name__, ))
self.bio = m2.bio_new(m2.bio_s_mem())
self._pyfree = 1
if data is not None:
m2.bio_write(self.bio, data)
def __len__(self):
# type: () -> int
return m2.bio_ctrl_pending(self.bio)
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def read(self, size=0):
# type: (int) -> bytes
m2.err_clear_error();
if not self.readable():
raise IOError('cannot read')
if size:
return m2.bio_read(self.bio, size)
else:
return m2.bio_read(self.bio, m2.bio_ctrl_pending(self.bio))
# Backwards-compatibility.
getvalue = read_all = read
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def write_close(self):
# type: () -> None
super(MemoryBuffer, self).write_close()
m2.bio_set_mem_eof_return(self.bio, 0)
close = write_close
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class File(BIO):
"""Object interface to BIO_s_pyfd.
This class interfaces Python to OpenSSL functions that expect BIO. For
general file manipulation in Python, use Python's builtin file object.
"""
def __init__(self, pyfile, close_pyfile=1, mode='rb'):
# type: (Union[io.BytesIO, AnyStr], int, AnyStr) -> None
super(File, self).__init__(self, _pyfree=1)
if isinstance(pyfile, str):
pyfile = open(pyfile, mode)
# This is for downward compatibility, but I don't think, that it is
# good practice to have two handles for the same file. Whats about
# concurrent write access? Last write, last wins? Especially since Py3
# has its own buffer management. See:
#
# https://docs.python.org/3.3/c-api/file.html
#
pyfile.flush()
self.fname = pyfile.name
self.pyfile = pyfile
# Be wary of https://github.com/openssl/openssl/pull/1925
# BIO_new_fd is NEVER to be used before OpenSSL 1.1.1
if hasattr(m2, "bio_new_pyfd"):
self.bio = m2.bio_new_pyfd(pyfile.fileno(), m2.bio_noclose)
else:
self.bio = m2.bio_new_pyfile(pyfile, m2.bio_noclose)
self.close_pyfile = close_pyfile
self.closed = False
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def flush(self):
# type: () -> None
super(File, self).flush()
self.pyfile.flush()
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def close(self):
# type: () -> None
self.flush()
super(File, self).close()
if self.close_pyfile:
self.pyfile.close()
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def reset(self):
# type: () -> int
"""Set the bio to its initial state.
:return: 0 for success, and -1 for failure
"""
return super(File, self).reset()
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def openfile(filename, mode='rb'):
# type: (AnyStr, AnyStr) -> File
try:
f = open(filename, mode)
except IOError as ex:
raise BIOError(ex.args)
return File(f)
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class IOBuffer(BIO):
"""Object interface to BIO_f_buffer.
Its principal function is to be BIO_push()'ed on top of a BIO_f_ssl, so
that makefile() of said underlying SSL socket works.
"""
m2_bio_pop = m2.bio_pop
m2_bio_free = m2.bio_free
def __init__(self, under_bio, mode='rwb', _pyfree=1):
# type: (BIO, str, int) -> None
super(IOBuffer, self).__init__(self, _pyfree=_pyfree)
self.io = m2.bio_new(m2.bio_f_buffer())
self.bio = m2.bio_push(self.io, under_bio._ptr())
# This reference keeps the underlying BIO alive while we're not closed.
self._under_bio = under_bio
if 'w' in mode:
self.write_closed = 0
else:
self.write_closed = 1
def __del__(self):
# type: () -> None
if getattr(self, '_pyfree', 0):
self.m2_bio_pop(self.bio)
self.m2_bio_free(self.io)
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def close(self):
# type: () -> None
BIO.close(self)
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class CipherStream(BIO):
"""Object interface to BIO_f_cipher."""
SALT_LEN = m2.PKCS5_SALT_LEN
m2_bio_pop = m2.bio_pop
m2_bio_free = m2.bio_free
def __init__(self, obio):
# type: (BIO) -> None
super(CipherStream, self).__init__(self, _pyfree=1)
self.obio = obio
self.bio = m2.bio_new(m2.bio_f_cipher())
self.closed = 0
def __del__(self):
# type: () -> None
if not getattr(self, 'closed', 1):
self.close()
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def close(self):
# type: () -> None
self.m2_bio_pop(self.bio)
self.m2_bio_free(self.bio)
self.closed = 1
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def write_close(self):
# type: () -> None
self.obio.write_close()
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def set_cipher(self, algo, key, iv, op):
# type: (str, AnyStr, AnyStr, int) -> None
cipher = getattr(m2, algo, None)
if cipher is None:
raise ValueError('unknown cipher', algo)
else:
if not isinstance(key, bytes):
key = key.encode('utf8')
if not isinstance(iv, bytes):
iv = iv.encode('utf8')
try:
m2.bio_set_cipher(self.bio, cipher(), key, iv, int(op))
except (OSError, ValueError) as ex:
raise BIOError("BIOError: {}".format(str(ex)))
m2.bio_push(self.bio, self.obio._ptr())
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class SSLBio(BIO):
"""Object interface to BIO_f_ssl."""
def __init__(self, _pyfree=1):
# type: (int) -> None
super(SSLBio, self).__init__(self, _pyfree=_pyfree)
self.bio = m2.bio_new(m2.bio_f_ssl())
self.closed = 0
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def set_ssl(self, conn, close_flag=m2.bio_noclose):
# type: (Any, int) -> None
# conn should actually be SSL.Connection, but we cannot import
# it here without getting into some serious circular dependency
# business.
"""
Sets the bio to the SSL pointer which is
contained in the connection object.
"""
self._pyfree = 0
m2.bio_set_ssl(self.bio, conn.ssl, close_flag)
if close_flag == m2.bio_noclose:
conn.set_ssl_close_flag(m2.bio_close)
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def do_handshake(self):
# type: () -> int
"""Do the handshake.
Return 1 if the handshake completes
Return 0 or a negative number if there is a problem
"""
return m2.bio_do_handshake(self.bio)