File: //var/opt/nydus/ops/oscrypto/_win/tls.py
# coding: utf-8
from __future__ import unicode_literals, division, absolute_import, print_function
import sys
import re
import socket as socket_
import select
import numbers
from .._asn1 import Certificate as Asn1Certificate
from .._errors import pretty_message
from .._ffi import (
buffer_from_bytes,
buffer_from_unicode,
bytes_from_buffer,
cast,
deref,
is_null,
native,
new,
null,
ref,
sizeof,
struct,
unwrap,
write_to_buffer,
)
from ._secur32 import secur32, Secur32Const, handle_error
from ._crypt32 import crypt32, Crypt32Const, handle_error as handle_crypt32_error
from ._kernel32 import kernel32
from .._types import type_name, str_cls, byte_cls, int_types
from ..errors import TLSError, TLSVerificationError, TLSDisconnectError, TLSGracefulDisconnectError
from .._tls import (
detect_client_auth_request,
detect_other_protocol,
extract_chain,
get_dh_params_length,
parse_alert,
parse_session_info,
raise_client_auth,
raise_dh_params,
raise_disconnection,
raise_expired_not_yet_valid,
raise_handshake,
raise_hostname,
raise_no_issuer,
raise_protocol_error,
raise_protocol_version,
raise_revoked,
raise_self_signed,
raise_verification,
raise_weak_signature,
)
from .asymmetric import load_certificate, Certificate
from ..keys import parse_certificate
if sys.version_info < (3,):
range = xrange # noqa
socket_error_cls = socket_.error
else:
socket_error_cls = WindowsError
if sys.version_info < (3, 7):
Pattern = re._pattern_type
else:
Pattern = re.Pattern
__all__ = [
'TLSSession',
'TLSSocket',
]
_line_regex = re.compile(b'(\r\n|\r|\n)')
_gwv = sys.getwindowsversion()
_win_version_info = (_gwv[0], _gwv[1])
class _TLSDowngradeError(TLSVerificationError):
pass
class _TLSRetryError(TLSError):
"""
TLSv1.2 on Windows 7 and 8 seems to have isuses with some DHE_RSA
ServerKeyExchange messages due to variable length integer encoding. This
exception is used to trigger a reconnection to attempt the handshake again.
"""
pass
class TLSSession(object):
"""
A TLS session object that multiple TLSSocket objects can share for the
sake of session reuse
"""
_protocols = None
_ciphers = None
_manual_validation = None
_extra_trust_roots = None
_credentials_handle = None
def __init__(self, protocol=None, manual_validation=False, extra_trust_roots=None):
"""
:param protocol:
A unicode string or set of unicode strings representing allowable
protocols to negotiate with the server:
- "TLSv1.2"
- "TLSv1.1"
- "TLSv1"
- "SSLv3"
Default is: {"TLSv1", "TLSv1.1", "TLSv1.2"}
:param manual_validation:
If certificate and certificate path validation should be skipped
and left to the developer to implement
:param extra_trust_roots:
A list containing one or more certificates to be treated as trust
roots, in one of the following formats:
- A byte string of the DER encoded certificate
- A unicode string of the certificate filename
- An asn1crypto.x509.Certificate object
- An oscrypto.asymmetric.Certificate object
:raises:
ValueError - when any of the parameters contain an invalid value
TypeError - when any of the parameters are of the wrong type
OSError - when an error is returned by the OS crypto library
"""
if not isinstance(manual_validation, bool):
raise TypeError(pretty_message(
'''
manual_validation must be a boolean, not %s
''',
type_name(manual_validation)
))
self._manual_validation = manual_validation
if protocol is None:
protocol = set(['TLSv1', 'TLSv1.1', 'TLSv1.2'])
if isinstance(protocol, str_cls):
protocol = set([protocol])
elif not isinstance(protocol, set):
raise TypeError(pretty_message(
'''
protocol must be a unicode string or set of unicode strings,
not %s
''',
type_name(protocol)
))
unsupported_protocols = protocol - set(['SSLv3', 'TLSv1', 'TLSv1.1', 'TLSv1.2'])
if unsupported_protocols:
raise ValueError(pretty_message(
'''
protocol must contain only the unicode strings "SSLv3", "TLSv1",
"TLSv1.1", "TLSv1.2", not %s
''',
repr(unsupported_protocols)
))
self._protocols = protocol
self._extra_trust_roots = []
if extra_trust_roots:
for extra_trust_root in extra_trust_roots:
if isinstance(extra_trust_root, Certificate):
extra_trust_root = extra_trust_root.asn1
elif isinstance(extra_trust_root, byte_cls):
extra_trust_root = parse_certificate(extra_trust_root)
elif isinstance(extra_trust_root, str_cls):
with open(extra_trust_root, 'rb') as f:
extra_trust_root = parse_certificate(f.read())
elif not isinstance(extra_trust_root, Asn1Certificate):
raise TypeError(pretty_message(
'''
extra_trust_roots must be a list of byte strings, unicode
strings, asn1crypto.x509.Certificate objects or
oscrypto.asymmetric.Certificate objects, not %s
''',
type_name(extra_trust_root)
))
self._extra_trust_roots.append(extra_trust_root)
self._obtain_credentials()
def _obtain_credentials(self):
"""
Obtains a credentials handle from secur32.dll for use with SChannel
"""
protocol_values = {
'SSLv3': Secur32Const.SP_PROT_SSL3_CLIENT,
'TLSv1': Secur32Const.SP_PROT_TLS1_CLIENT,
'TLSv1.1': Secur32Const.SP_PROT_TLS1_1_CLIENT,
'TLSv1.2': Secur32Const.SP_PROT_TLS1_2_CLIENT,
}
protocol_bit_mask = 0
for key, value in protocol_values.items():
if key in self._protocols:
protocol_bit_mask |= value
algs = [
Secur32Const.CALG_AES_128,
Secur32Const.CALG_AES_256,
Secur32Const.CALG_3DES,
Secur32Const.CALG_SHA1,
Secur32Const.CALG_ECDHE,
Secur32Const.CALG_DH_EPHEM,
Secur32Const.CALG_RSA_KEYX,
Secur32Const.CALG_RSA_SIGN,
Secur32Const.CALG_ECDSA,
Secur32Const.CALG_DSS_SIGN,
]
if 'TLSv1.2' in self._protocols:
algs.extend([
Secur32Const.CALG_SHA512,
Secur32Const.CALG_SHA384,
Secur32Const.CALG_SHA256,
])
alg_array = new(secur32, 'ALG_ID[%s]' % len(algs))
for index, alg in enumerate(algs):
alg_array[index] = alg
flags = Secur32Const.SCH_USE_STRONG_CRYPTO | Secur32Const.SCH_CRED_NO_DEFAULT_CREDS
if not self._manual_validation and not self._extra_trust_roots:
flags |= Secur32Const.SCH_CRED_AUTO_CRED_VALIDATION
else:
flags |= Secur32Const.SCH_CRED_MANUAL_CRED_VALIDATION
schannel_cred_pointer = struct(secur32, 'SCHANNEL_CRED')
schannel_cred = unwrap(schannel_cred_pointer)
schannel_cred.dwVersion = Secur32Const.SCHANNEL_CRED_VERSION
schannel_cred.cCreds = 0
schannel_cred.paCred = null()
schannel_cred.hRootStore = null()
schannel_cred.cMappers = 0
schannel_cred.aphMappers = null()
schannel_cred.cSupportedAlgs = len(alg_array)
schannel_cred.palgSupportedAlgs = alg_array
schannel_cred.grbitEnabledProtocols = protocol_bit_mask
schannel_cred.dwMinimumCipherStrength = 0
schannel_cred.dwMaximumCipherStrength = 0
# Default session lifetime is 10 hours
schannel_cred.dwSessionLifespan = 0
schannel_cred.dwFlags = flags
schannel_cred.dwCredFormat = 0
cred_handle_pointer = new(secur32, 'CredHandle *')
result = secur32.AcquireCredentialsHandleW(
null(),
Secur32Const.UNISP_NAME,
Secur32Const.SECPKG_CRED_OUTBOUND,
null(),
schannel_cred_pointer,
null(),
null(),
cred_handle_pointer,
null()
)
handle_error(result)
self._credentials_handle = cred_handle_pointer
def __del__(self):
if self._credentials_handle:
result = secur32.FreeCredentialsHandle(self._credentials_handle)
handle_error(result)
self._credentials_handle = None
class TLSSocket(object):
"""
A wrapper around a socket.socket that adds TLS
"""
_socket = None
_session = None
_context_handle_pointer = None
_context_flags = None
_hostname = None
_header_size = None
_message_size = None
_trailer_size = None
_received_bytes = None
_decrypted_bytes = None
_encrypt_desc = None
_encrypt_buffers = None
_encrypt_data_buffer = None
_decrypt_desc = None
_decrypt_buffers = None
_decrypt_data_buffer = None
_certificate = None
_intermediates = None
_protocol = None
_cipher_suite = None
_compression = None
_session_id = None
_session_ticket = None
_remote_closed = False
@classmethod
def wrap(cls, socket, hostname, session=None):
"""
Takes an existing socket and adds TLS
:param socket:
A socket.socket object to wrap with TLS
:param hostname:
A unicode string of the hostname or IP the socket is connected to
:param session:
An existing TLSSession object to allow for session reuse, specific
protocol or manual certificate validation
:raises:
ValueError - when any of the parameters contain an invalid value
TypeError - when any of the parameters are of the wrong type
OSError - when an error is returned by the OS crypto library
"""
if not isinstance(socket, socket_.socket):
raise TypeError(pretty_message(
'''
socket must be an instance of socket.socket, not %s
''',
type_name(socket)
))
if not isinstance(hostname, str_cls):
raise TypeError(pretty_message(
'''
hostname must be a unicode string, not %s
''',
type_name(hostname)
))
if session is not None and not isinstance(session, TLSSession):
raise TypeError(pretty_message(
'''
session must be an instance of oscrypto.tls.TLSSession, not %s
''',
type_name(session)
))
new_socket = cls(None, None, session=session)
new_socket._socket = socket
new_socket._hostname = hostname
# Since we don't create the socket connection here, we can't try to
# reconnect with a lower version of the TLS protocol, so we just
# move the data to public exception type TLSVerificationError()
try:
new_socket._handshake()
except (_TLSDowngradeError) as e:
new_e = TLSVerificationError(e.message, e.certificate)
raise new_e
except (_TLSRetryError) as e:
new_e = TLSError(e.message)
raise new_e
return new_socket
def __init__(self, address, port, timeout=10, session=None):
"""
:param address:
A unicode string of the domain name or IP address to connect to
:param port:
An integer of the port number to connect to
:param timeout:
An integer timeout to use for the socket
:param session:
An oscrypto.tls.TLSSession object to allow for session reuse and
controlling the protocols and validation performed
"""
self._received_bytes = b''
self._decrypted_bytes = b''
if address is None and port is None:
self._socket = None
else:
if not isinstance(address, str_cls):
raise TypeError(pretty_message(
'''
address must be a unicode string, not %s
''',
type_name(address)
))
if not isinstance(port, int_types):
raise TypeError(pretty_message(
'''
port must be an integer, not %s
''',
type_name(port)
))
if timeout is not None and not isinstance(timeout, numbers.Number):
raise TypeError(pretty_message(
'''
timeout must be a number, not %s
''',
type_name(timeout)
))
self._socket = socket_.create_connection((address, port), timeout)
self._socket.settimeout(timeout)
if session is None:
session = TLSSession()
elif not isinstance(session, TLSSession):
raise TypeError(pretty_message(
'''
session must be an instance of oscrypto.tls.TLSSession, not %s
''',
type_name(session)
))
self._session = session
if self._socket:
self._hostname = address
try:
self._handshake()
except (_TLSDowngradeError):
self.close()
new_session = TLSSession(
session._protocols - set(['TLSv1.2']),
session._manual_validation,
session._extra_trust_roots
)
session.__del__()
self._received_bytes = b''
self._session = new_session
self._socket = socket_.create_connection((address, port), timeout)
self._socket.settimeout(timeout)
self._handshake()
except (_TLSRetryError):
self._received_bytes = b''
self._socket = socket_.create_connection((address, port), timeout)
self._socket.settimeout(timeout)
self._handshake()
def _create_buffers(self, number):
"""
Creates a SecBufferDesc struct and contained SecBuffer structs
:param number:
The number of contains SecBuffer objects to create
:return:
A tuple of (SecBufferDesc pointer, SecBuffer array)
"""
buffers = new(secur32, 'SecBuffer[%d]' % number)
for index in range(0, number):
buffers[index].cbBuffer = 0
buffers[index].BufferType = Secur32Const.SECBUFFER_EMPTY
buffers[index].pvBuffer = null()
sec_buffer_desc_pointer = struct(secur32, 'SecBufferDesc')
sec_buffer_desc = unwrap(sec_buffer_desc_pointer)
sec_buffer_desc.ulVersion = Secur32Const.SECBUFFER_VERSION
sec_buffer_desc.cBuffers = number
sec_buffer_desc.pBuffers = buffers
return (sec_buffer_desc_pointer, buffers)
def _extra_trust_root_validation(self):
"""
Manually invoked windows certificate chain builder and verification
step when there are extra trust roots to include in the search process
"""
store = None
cert_chain_context_pointer = None
try:
# We set up an in-memory store to pass as an extra store to grab
# certificates from when performing the verification
store = crypt32.CertOpenStore(
Crypt32Const.CERT_STORE_PROV_MEMORY,
Crypt32Const.X509_ASN_ENCODING,
null(),
0,
null()
)
if is_null(store):
handle_crypt32_error(0)
cert_hashes = set()
for cert in self._session._extra_trust_roots:
cert_data = cert.dump()
result = crypt32.CertAddEncodedCertificateToStore(
store,
Crypt32Const.X509_ASN_ENCODING,
cert_data,
len(cert_data),
Crypt32Const.CERT_STORE_ADD_USE_EXISTING,
null()
)
if not result:
handle_crypt32_error(0)
cert_hashes.add(cert.sha256)
cert_context_pointer_pointer = new(crypt32, 'PCERT_CONTEXT *')
result = secur32.QueryContextAttributesW(
self._context_handle_pointer,
Secur32Const.SECPKG_ATTR_REMOTE_CERT_CONTEXT,
cert_context_pointer_pointer
)
handle_error(result)
cert_context_pointer = unwrap(cert_context_pointer_pointer)
cert_context_pointer = cast(crypt32, 'PCERT_CONTEXT', cert_context_pointer)
# We have to do a funky shuffle here because FILETIME from kernel32
# is different than FILETIME from crypt32 when using cffi. If we
# overwrite the "now_pointer" variable, cffi releases the backing
# memory and we end up getting a validation error about certificate
# expiration time.
orig_now_pointer = new(kernel32, 'FILETIME *')
kernel32.GetSystemTimeAsFileTime(orig_now_pointer)
now_pointer = cast(crypt32, 'FILETIME *', orig_now_pointer)
usage_identifiers = new(crypt32, 'char *[3]')
usage_identifiers[0] = cast(crypt32, 'char *', Crypt32Const.PKIX_KP_SERVER_AUTH)
usage_identifiers[1] = cast(crypt32, 'char *', Crypt32Const.SERVER_GATED_CRYPTO)
usage_identifiers[2] = cast(crypt32, 'char *', Crypt32Const.SGC_NETSCAPE)
cert_enhkey_usage_pointer = struct(crypt32, 'CERT_ENHKEY_USAGE')
cert_enhkey_usage = unwrap(cert_enhkey_usage_pointer)
cert_enhkey_usage.cUsageIdentifier = 3
cert_enhkey_usage.rgpszUsageIdentifier = cast(crypt32, 'char **', usage_identifiers)
cert_usage_match_pointer = struct(crypt32, 'CERT_USAGE_MATCH')
cert_usage_match = unwrap(cert_usage_match_pointer)
cert_usage_match.dwType = Crypt32Const.USAGE_MATCH_TYPE_OR
cert_usage_match.Usage = cert_enhkey_usage
cert_chain_para_pointer = struct(crypt32, 'CERT_CHAIN_PARA')
cert_chain_para = unwrap(cert_chain_para_pointer)
cert_chain_para.RequestedUsage = cert_usage_match
cert_chain_para_size = sizeof(crypt32, cert_chain_para)
cert_chain_para.cbSize = cert_chain_para_size
cert_chain_context_pointer_pointer = new(crypt32, 'PCERT_CHAIN_CONTEXT *')
result = crypt32.CertGetCertificateChain(
null(),
cert_context_pointer,
now_pointer,
store,
cert_chain_para_pointer,
Crypt32Const.CERT_CHAIN_CACHE_END_CERT | Crypt32Const.CERT_CHAIN_REVOCATION_CHECK_CACHE_ONLY,
null(),
cert_chain_context_pointer_pointer
)
handle_crypt32_error(result)
cert_chain_policy_para_flags = Crypt32Const.CERT_CHAIN_POLICY_IGNORE_ALL_REV_UNKNOWN_FLAGS
cert_chain_context_pointer = unwrap(cert_chain_context_pointer_pointer)
# Unwrap the chain and if the final element in the chain is one of
# extra trust roots, set flags so that we trust the certificate even
# though it is not in the Trusted Roots store
cert_chain_context = unwrap(cert_chain_context_pointer)
num_chains = native(int, cert_chain_context.cChain)
if num_chains == 1:
first_simple_chain_pointer = unwrap(cert_chain_context.rgpChain)
first_simple_chain = unwrap(first_simple_chain_pointer)
num_elements = native(int, first_simple_chain.cElement)
last_element_pointer = first_simple_chain.rgpElement[num_elements - 1]
last_element = unwrap(last_element_pointer)
last_element_cert = unwrap(last_element.pCertContext)
last_element_cert_data = bytes_from_buffer(
last_element_cert.pbCertEncoded,
native(int, last_element_cert.cbCertEncoded)
)
last_cert = Asn1Certificate.load(last_element_cert_data)
if last_cert.sha256 in cert_hashes:
cert_chain_policy_para_flags |= Crypt32Const.CERT_CHAIN_POLICY_ALLOW_UNKNOWN_CA_FLAG
ssl_extra_cert_chain_policy_para_pointer = struct(crypt32, 'SSL_EXTRA_CERT_CHAIN_POLICY_PARA')
ssl_extra_cert_chain_policy_para = unwrap(ssl_extra_cert_chain_policy_para_pointer)
ssl_extra_cert_chain_policy_para.cbSize = sizeof(crypt32, ssl_extra_cert_chain_policy_para)
ssl_extra_cert_chain_policy_para.dwAuthType = Crypt32Const.AUTHTYPE_SERVER
ssl_extra_cert_chain_policy_para.fdwChecks = 0
ssl_extra_cert_chain_policy_para.pwszServerName = cast(
crypt32,
'wchar_t *',
buffer_from_unicode(self._hostname)
)
cert_chain_policy_para_pointer = struct(crypt32, 'CERT_CHAIN_POLICY_PARA')
cert_chain_policy_para = unwrap(cert_chain_policy_para_pointer)
cert_chain_policy_para.cbSize = sizeof(crypt32, cert_chain_policy_para)
cert_chain_policy_para.dwFlags = cert_chain_policy_para_flags
cert_chain_policy_para.pvExtraPolicyPara = cast(crypt32, 'void *', ssl_extra_cert_chain_policy_para_pointer)
cert_chain_policy_status_pointer = struct(crypt32, 'CERT_CHAIN_POLICY_STATUS')
cert_chain_policy_status = unwrap(cert_chain_policy_status_pointer)
cert_chain_policy_status.cbSize = sizeof(crypt32, cert_chain_policy_status)
result = crypt32.CertVerifyCertificateChainPolicy(
Crypt32Const.CERT_CHAIN_POLICY_SSL,
cert_chain_context_pointer,
cert_chain_policy_para_pointer,
cert_chain_policy_status_pointer
)
handle_crypt32_error(result)
cert_context = unwrap(cert_context_pointer)
cert_data = bytes_from_buffer(cert_context.pbCertEncoded, native(int, cert_context.cbCertEncoded))
cert = Asn1Certificate.load(cert_data)
error = cert_chain_policy_status.dwError
if error:
if error == Crypt32Const.CERT_E_EXPIRED:
raise_expired_not_yet_valid(cert)
if error == Crypt32Const.CERT_E_UNTRUSTEDROOT:
oscrypto_cert = load_certificate(cert)
if oscrypto_cert.self_signed:
raise_self_signed(cert)
else:
raise_no_issuer(cert)
if error == Crypt32Const.CERT_E_CN_NO_MATCH:
raise_hostname(cert, self._hostname)
if error == Crypt32Const.TRUST_E_CERT_SIGNATURE:
raise_weak_signature(cert)
if error == Crypt32Const.CRYPT_E_REVOKED:
raise_revoked(cert)
raise_verification(cert)
if cert.hash_algo in set(['md5', 'md2']):
raise_weak_signature(cert)
finally:
if store:
crypt32.CertCloseStore(store, 0)
if cert_chain_context_pointer:
crypt32.CertFreeCertificateChain(cert_chain_context_pointer)
def _handshake(self, renegotiate=False):
"""
Perform an initial TLS handshake, or a renegotiation
:param renegotiate:
If the handshake is for a renegotiation
"""
in_buffers = None
out_buffers = None
new_context_handle_pointer = None
try:
if renegotiate:
temp_context_handle_pointer = self._context_handle_pointer
else:
new_context_handle_pointer = new(secur32, 'CtxtHandle *')
temp_context_handle_pointer = new_context_handle_pointer
requested_flags = {
Secur32Const.ISC_REQ_REPLAY_DETECT: 'replay detection',
Secur32Const.ISC_REQ_SEQUENCE_DETECT: 'sequence detection',
Secur32Const.ISC_REQ_CONFIDENTIALITY: 'confidentiality',
Secur32Const.ISC_REQ_ALLOCATE_MEMORY: 'memory allocation',
Secur32Const.ISC_REQ_INTEGRITY: 'integrity',
Secur32Const.ISC_REQ_STREAM: 'stream orientation',
Secur32Const.ISC_REQ_USE_SUPPLIED_CREDS: 'disable automatic client auth',
}
self._context_flags = 0
for flag in requested_flags:
self._context_flags |= flag
in_sec_buffer_desc_pointer, in_buffers = self._create_buffers(2)
in_buffers[0].BufferType = Secur32Const.SECBUFFER_TOKEN
out_sec_buffer_desc_pointer, out_buffers = self._create_buffers(2)
out_buffers[0].BufferType = Secur32Const.SECBUFFER_TOKEN
out_buffers[1].BufferType = Secur32Const.SECBUFFER_ALERT
output_context_flags_pointer = new(secur32, 'ULONG *')
if renegotiate:
first_handle = temp_context_handle_pointer
second_handle = null()
else:
first_handle = null()
second_handle = temp_context_handle_pointer
result = secur32.InitializeSecurityContextW(
self._session._credentials_handle,
first_handle,
self._hostname,
self._context_flags,
0,
0,
null(),
0,
second_handle,
out_sec_buffer_desc_pointer,
output_context_flags_pointer,
null()
)
if result not in set([Secur32Const.SEC_E_OK, Secur32Const.SEC_I_CONTINUE_NEEDED]):
handle_error(result, TLSError)
if not renegotiate:
temp_context_handle_pointer = second_handle
else:
temp_context_handle_pointer = first_handle
handshake_server_bytes = b''
handshake_client_bytes = b''
if out_buffers[0].cbBuffer > 0:
token = bytes_from_buffer(out_buffers[0].pvBuffer, out_buffers[0].cbBuffer)
handshake_client_bytes += token
self._socket.send(token)
out_buffers[0].cbBuffer = 0
secur32.FreeContextBuffer(out_buffers[0].pvBuffer)
out_buffers[0].pvBuffer = null()
in_data_buffer = buffer_from_bytes(32768)
in_buffers[0].pvBuffer = cast(secur32, 'BYTE *', in_data_buffer)
bytes_read = b''
while result != Secur32Const.SEC_E_OK:
try:
fail_late = False
bytes_read = self._socket.recv(8192)
if bytes_read == b'':
raise_disconnection()
except (socket_error_cls):
fail_late = True
handshake_server_bytes += bytes_read
self._received_bytes += bytes_read
in_buffers[0].cbBuffer = len(self._received_bytes)
write_to_buffer(in_data_buffer, self._received_bytes)
result = secur32.InitializeSecurityContextW(
self._session._credentials_handle,
temp_context_handle_pointer,
self._hostname,
self._context_flags,
0,
0,
in_sec_buffer_desc_pointer,
0,
null(),
out_sec_buffer_desc_pointer,
output_context_flags_pointer,
null()
)
if result == Secur32Const.SEC_E_INCOMPLETE_MESSAGE:
in_buffers[0].BufferType = Secur32Const.SECBUFFER_TOKEN
# Windows 10 seems to fill the second input buffer with
# a BufferType of SECBUFFER_MISSING (4), which if not
# cleared causes the handshake to fail.
if in_buffers[1].BufferType != Secur32Const.SECBUFFER_EMPTY:
in_buffers[1].BufferType = Secur32Const.SECBUFFER_EMPTY
in_buffers[1].cbBuffer = 0
if not is_null(in_buffers[1].pvBuffer):
secur32.FreeContextBuffer(in_buffers[1].pvBuffer)
in_buffers[1].pvBuffer = null()
if fail_late:
raise_disconnection()
continue
if result == Secur32Const.SEC_E_ILLEGAL_MESSAGE:
if detect_client_auth_request(handshake_server_bytes):
raise_client_auth()
alert_info = parse_alert(handshake_server_bytes)
if alert_info and alert_info == (2, 70):
raise_protocol_version()
raise_handshake()
if result == Secur32Const.SEC_E_WRONG_PRINCIPAL:
chain = extract_chain(handshake_server_bytes)
raise_hostname(chain[0], self._hostname)
if result == Secur32Const.SEC_E_CERT_EXPIRED:
chain = extract_chain(handshake_server_bytes)
raise_expired_not_yet_valid(chain[0])
if result == Secur32Const.SEC_E_UNTRUSTED_ROOT:
chain = extract_chain(handshake_server_bytes)
cert = chain[0]
oscrypto_cert = load_certificate(cert)
if not oscrypto_cert.self_signed:
raise_no_issuer(cert)
raise_self_signed(cert)
if result == Secur32Const.SEC_E_INTERNAL_ERROR:
if get_dh_params_length(handshake_server_bytes) < 1024:
raise_dh_params()
if result == Secur32Const.SEC_I_INCOMPLETE_CREDENTIALS:
raise_client_auth()
if result == Crypt32Const.TRUST_E_CERT_SIGNATURE:
raise_weak_signature(cert)
if result == Secur32Const.SEC_E_INVALID_TOKEN:
# If an alert it present, there may have been a handshake
# error due to the server using a certificate path with a
# trust root using MD2 or MD5 combined with TLS 1.2. To
# work around this, if the user allows anything other than
# TLS 1.2, we just remove it from the acceptable protocols
# and try again.
if out_buffers[1].cbBuffer > 0:
alert_bytes = bytes_from_buffer(out_buffers[1].pvBuffer, out_buffers[1].cbBuffer)
handshake_client_bytes += alert_bytes
alert_number = alert_bytes[6:7]
if alert_number == b'\x28' or alert_number == b'\x2b':
if 'TLSv1.2' in self._session._protocols and len(self._session._protocols) > 1:
chain = extract_chain(handshake_server_bytes)
raise _TLSDowngradeError(
'Server certificate verification failed - weak certificate signature algorithm',
chain[0]
)
if detect_client_auth_request(handshake_server_bytes):
raise_client_auth()
if detect_other_protocol(handshake_server_bytes):
raise_protocol_error(handshake_server_bytes)
raise_handshake()
# These are semi-common errors with TLSv1.2 on Windows 7 an 8
# that appears to be due to poor handling of the
# ServerKeyExchange for DHE_RSA cipher suites. The solution
# is to retry the handshake.
if result == Secur32Const.SEC_E_BUFFER_TOO_SMALL or result == Secur32Const.SEC_E_MESSAGE_ALTERED:
if 'TLSv1.2' in self._session._protocols:
raise _TLSRetryError('TLS handshake failed')
if fail_late:
raise_disconnection()
if result == Secur32Const.SEC_E_INVALID_PARAMETER:
if get_dh_params_length(handshake_server_bytes) < 1024:
raise_dh_params()
if result not in set([Secur32Const.SEC_E_OK, Secur32Const.SEC_I_CONTINUE_NEEDED]):
handle_error(result, TLSError)
if out_buffers[0].cbBuffer > 0:
token = bytes_from_buffer(out_buffers[0].pvBuffer, out_buffers[0].cbBuffer)
handshake_client_bytes += token
self._socket.send(token)
out_buffers[0].cbBuffer = 0
secur32.FreeContextBuffer(out_buffers[0].pvBuffer)
out_buffers[0].pvBuffer = null()
if in_buffers[1].BufferType == Secur32Const.SECBUFFER_EXTRA:
extra_amount = in_buffers[1].cbBuffer
self._received_bytes = self._received_bytes[-extra_amount:]
in_buffers[1].BufferType = Secur32Const.SECBUFFER_EMPTY
in_buffers[1].cbBuffer = 0
secur32.FreeContextBuffer(in_buffers[1].pvBuffer)
in_buffers[1].pvBuffer = null()
# The handshake is complete, so discard any extra bytes
if result == Secur32Const.SEC_E_OK:
handshake_server_bytes = handshake_server_bytes[-extra_amount:]
else:
self._received_bytes = b''
connection_info_pointer = struct(secur32, 'SecPkgContext_ConnectionInfo')
result = secur32.QueryContextAttributesW(
temp_context_handle_pointer,
Secur32Const.SECPKG_ATTR_CONNECTION_INFO,
connection_info_pointer
)
handle_error(result, TLSError)
connection_info = unwrap(connection_info_pointer)
self._protocol = {
Secur32Const.SP_PROT_SSL2_CLIENT: 'SSLv2',
Secur32Const.SP_PROT_SSL3_CLIENT: 'SSLv3',
Secur32Const.SP_PROT_TLS1_CLIENT: 'TLSv1',
Secur32Const.SP_PROT_TLS1_1_CLIENT: 'TLSv1.1',
Secur32Const.SP_PROT_TLS1_2_CLIENT: 'TLSv1.2',
}.get(native(int, connection_info.dwProtocol), str_cls(connection_info.dwProtocol))
if self._protocol in set(['SSLv3', 'TLSv1', 'TLSv1.1', 'TLSv1.2']):
session_info = parse_session_info(handshake_server_bytes, handshake_client_bytes)
self._cipher_suite = session_info['cipher_suite']
self._compression = session_info['compression']
self._session_id = session_info['session_id']
self._session_ticket = session_info['session_ticket']
output_context_flags = deref(output_context_flags_pointer)
for flag in requested_flags:
if (flag | output_context_flags) == 0:
raise OSError(pretty_message(
'''
Unable to obtain a credential context with the property %s
''',
requested_flags[flag]
))
if not renegotiate:
self._context_handle_pointer = temp_context_handle_pointer
new_context_handle_pointer = None
stream_sizes_pointer = struct(secur32, 'SecPkgContext_StreamSizes')
result = secur32.QueryContextAttributesW(
self._context_handle_pointer,
Secur32Const.SECPKG_ATTR_STREAM_SIZES,
stream_sizes_pointer
)
handle_error(result)
stream_sizes = unwrap(stream_sizes_pointer)
self._header_size = native(int, stream_sizes.cbHeader)
self._message_size = native(int, stream_sizes.cbMaximumMessage)
self._trailer_size = native(int, stream_sizes.cbTrailer)
self._buffer_size = self._header_size + self._message_size + self._trailer_size
if self._session._extra_trust_roots:
self._extra_trust_root_validation()
except (OSError, socket_.error):
self.close()
raise
finally:
if out_buffers:
if not is_null(out_buffers[0].pvBuffer):
secur32.FreeContextBuffer(out_buffers[0].pvBuffer)
if not is_null(out_buffers[1].pvBuffer):
secur32.FreeContextBuffer(out_buffers[1].pvBuffer)
if new_context_handle_pointer:
secur32.DeleteSecurityContext(new_context_handle_pointer)
def read(self, max_length):
"""
Reads data from the TLS-wrapped socket
:param max_length:
The number of bytes to read
:raises:
socket.socket - when a non-TLS socket error occurs
oscrypto.errors.TLSError - when a TLS-related error occurs
ValueError - when any of the parameters contain an invalid value
TypeError - when any of the parameters are of the wrong type
OSError - when an error is returned by the OS crypto library
:return:
A byte string of the data read
"""
if not isinstance(max_length, int_types):
raise TypeError(pretty_message(
'''
max_length must be an integer, not %s
''',
type_name(max_length)
))
if self._context_handle_pointer is None:
# Allow the user to read any remaining decrypted data
if self._decrypted_bytes != b'':
output = self._decrypted_bytes[0:max_length]
self._decrypted_bytes = self._decrypted_bytes[max_length:]
return output
self._raise_closed()
# The first time read is called, set up a single contiguous buffer that
# it used by DecryptMessage() to populate the three output buffers.
# Since we are creating the buffer, we do not need to free it other
# than allowing Python to GC it once this object is GCed.
if not self._decrypt_data_buffer:
self._decrypt_data_buffer = buffer_from_bytes(self._buffer_size)
self._decrypt_desc, self._decrypt_buffers = self._create_buffers(4)
self._decrypt_buffers[0].BufferType = Secur32Const.SECBUFFER_DATA
self._decrypt_buffers[0].pvBuffer = cast(secur32, 'BYTE *', self._decrypt_data_buffer)
to_recv = max(max_length, self._buffer_size)
# These variables are set to reduce dict access and function calls
# in the read loop. Also makes the code easier to read.
null_value = null()
buf0 = self._decrypt_buffers[0]
buf1 = self._decrypt_buffers[1]
buf2 = self._decrypt_buffers[2]
buf3 = self._decrypt_buffers[3]
def _reset_buffers():
buf0.BufferType = Secur32Const.SECBUFFER_DATA
buf0.pvBuffer = cast(secur32, 'BYTE *', self._decrypt_data_buffer)
buf0.cbBuffer = 0
buf1.BufferType = Secur32Const.SECBUFFER_EMPTY
buf1.pvBuffer = null_value
buf1.cbBuffer = 0
buf2.BufferType = Secur32Const.SECBUFFER_EMPTY
buf2.pvBuffer = null_value
buf2.cbBuffer = 0
buf3.BufferType = Secur32Const.SECBUFFER_EMPTY
buf3.pvBuffer = null_value
buf3.cbBuffer = 0
output = self._decrypted_bytes
output_len = len(output)
self._decrypted_bytes = b''
# Don't block if we have buffered data available
if output_len > 0 and not self.select_read(0):
self._decrypted_bytes = b''
return output
# This read loop will only be run if there wasn't enough
# buffered data to fulfill the requested max_length
do_read = len(self._received_bytes) == 0
while output_len < max_length:
if do_read:
self._received_bytes += self._socket.recv(to_recv)
if len(self._received_bytes) == 0:
raise_disconnection()
data_len = min(len(self._received_bytes), self._buffer_size)
if data_len == 0:
break
self._decrypt_buffers[0].cbBuffer = data_len
write_to_buffer(self._decrypt_data_buffer, self._received_bytes[0:data_len])
result = secur32.DecryptMessage(
self._context_handle_pointer,
self._decrypt_desc,
0,
null()
)
do_read = False
if result == Secur32Const.SEC_E_INCOMPLETE_MESSAGE:
_reset_buffers()
do_read = True
continue
elif result == Secur32Const.SEC_I_CONTEXT_EXPIRED:
self._remote_closed = True
self.shutdown()
break
elif result == Secur32Const.SEC_I_RENEGOTIATE:
self._handshake(renegotiate=True)
return self.read(max_length)
elif result != Secur32Const.SEC_E_OK:
handle_error(result, TLSError)
valid_buffer_types = set([
Secur32Const.SECBUFFER_EMPTY,
Secur32Const.SECBUFFER_STREAM_HEADER,
Secur32Const.SECBUFFER_STREAM_TRAILER
])
extra_amount = None
for buf in (buf0, buf1, buf2, buf3):
buffer_type = buf.BufferType
if buffer_type == Secur32Const.SECBUFFER_DATA:
output += bytes_from_buffer(buf.pvBuffer, buf.cbBuffer)
output_len = len(output)
elif buffer_type == Secur32Const.SECBUFFER_EXTRA:
extra_amount = native(int, buf.cbBuffer)
elif buffer_type not in valid_buffer_types:
raise OSError(pretty_message(
'''
Unexpected decrypt output buffer of type %s
''',
buffer_type
))
if extra_amount:
self._received_bytes = self._received_bytes[data_len - extra_amount:]
else:
self._received_bytes = self._received_bytes[data_len:]
# Here we reset the structs for the next call to DecryptMessage()
_reset_buffers()
# If we have read something, but there is nothing left to read, we
# break so that we don't block for longer than necessary
if self.select_read(0):
do_read = True
if not do_read and len(self._received_bytes) == 0:
break
# If the output is more than we requested (because data is decrypted in
# blocks), we save the extra in a buffer
if len(output) > max_length:
self._decrypted_bytes = output[max_length:]
output = output[0:max_length]
return output
def select_read(self, timeout=None):
"""
Blocks until the socket is ready to be read from, or the timeout is hit
:param timeout:
A float - the period of time to wait for data to be read. None for
no time limit.
:return:
A boolean - if data is ready to be read. Will only be False if
timeout is not None.
"""
# If we have buffered data, we consider a read possible
if len(self._decrypted_bytes) > 0:
return True
read_ready, _, _ = select.select([self._socket], [], [], timeout)
return len(read_ready) > 0
def read_until(self, marker):
"""
Reads data from the socket until a marker is found. Data read may
include data beyond the marker.
:param marker:
A byte string or regex object from re.compile(). Used to determine
when to stop reading. Regex objects are more inefficient since
they must scan the entire byte string of read data each time data
is read off the socket.
:return:
A byte string of the data read
"""
if not isinstance(marker, byte_cls) and not isinstance(marker, Pattern):
raise TypeError(pretty_message(
'''
marker must be a byte string or compiled regex object, not %s
''',
type_name(marker)
))
output = b''
is_regex = isinstance(marker, Pattern)
while True:
if len(self._decrypted_bytes) > 0:
chunk = self._decrypted_bytes
self._decrypted_bytes = b''
else:
chunk = self.read(8192)
offset = len(output)
output += chunk
if is_regex:
match = marker.search(output)
if match is not None:
end = match.end()
break
else:
# If the marker was not found last time, we have to start
# at a position where the marker would have its final char
# in the newly read chunk
start = max(0, offset - len(marker) - 1)
match = output.find(marker, start)
if match != -1:
end = match + len(marker)
break
self._decrypted_bytes = output[end:] + self._decrypted_bytes
return output[0:end]
def read_line(self):
r"""
Reads a line from the socket, including the line ending of "\r\n", "\r",
or "\n"
:return:
A byte string of the next line from the socket
"""
return self.read_until(_line_regex)
def read_exactly(self, num_bytes):
"""
Reads exactly the specified number of bytes from the socket
:param num_bytes:
An integer - the exact number of bytes to read
:return:
A byte string of the data that was read
"""
output = b''
remaining = num_bytes
while remaining > 0:
output += self.read(remaining)
remaining = num_bytes - len(output)
return output
def write(self, data):
"""
Writes data to the TLS-wrapped socket
:param data:
A byte string to write to the socket
:raises:
socket.socket - when a non-TLS socket error occurs
oscrypto.errors.TLSError - when a TLS-related error occurs
ValueError - when any of the parameters contain an invalid value
TypeError - when any of the parameters are of the wrong type
OSError - when an error is returned by the OS crypto library
"""
if self._context_handle_pointer is None:
self._raise_closed()
if not self._encrypt_data_buffer:
self._encrypt_data_buffer = buffer_from_bytes(self._header_size + self._message_size + self._trailer_size)
self._encrypt_desc, self._encrypt_buffers = self._create_buffers(4)
self._encrypt_buffers[0].BufferType = Secur32Const.SECBUFFER_STREAM_HEADER
self._encrypt_buffers[0].cbBuffer = self._header_size
self._encrypt_buffers[0].pvBuffer = cast(secur32, 'BYTE *', self._encrypt_data_buffer)
self._encrypt_buffers[1].BufferType = Secur32Const.SECBUFFER_DATA
self._encrypt_buffers[1].pvBuffer = ref(self._encrypt_data_buffer, self._header_size)
self._encrypt_buffers[2].BufferType = Secur32Const.SECBUFFER_STREAM_TRAILER
self._encrypt_buffers[2].cbBuffer = self._trailer_size
self._encrypt_buffers[2].pvBuffer = ref(self._encrypt_data_buffer, self._header_size + self._message_size)
while len(data) > 0:
to_write = min(len(data), self._message_size)
write_to_buffer(self._encrypt_data_buffer, data[0:to_write], self._header_size)
self._encrypt_buffers[1].cbBuffer = to_write
self._encrypt_buffers[2].pvBuffer = ref(self._encrypt_data_buffer, self._header_size + to_write)
result = secur32.EncryptMessage(
self._context_handle_pointer,
0,
self._encrypt_desc,
0
)
if result != Secur32Const.SEC_E_OK:
handle_error(result, TLSError)
to_send = native(int, self._encrypt_buffers[0].cbBuffer)
to_send += native(int, self._encrypt_buffers[1].cbBuffer)
to_send += native(int, self._encrypt_buffers[2].cbBuffer)
try:
self._socket.send(bytes_from_buffer(self._encrypt_data_buffer, to_send))
except (socket_.error) as e:
if e.errno == 10053:
raise_disconnection()
raise
data = data[to_send:]
def select_write(self, timeout=None):
"""
Blocks until the socket is ready to be written to, or the timeout is hit
:param timeout:
A float - the period of time to wait for the socket to be ready to
written to. None for no time limit.
:return:
A boolean - if the socket is ready for writing. Will only be False
if timeout is not None.
"""
_, write_ready, _ = select.select([], [self._socket], [], timeout)
return len(write_ready) > 0
def shutdown(self):
"""
Shuts down the TLS session and then shuts down the underlying socket
:raises:
OSError - when an error is returned by the OS crypto library
"""
if self._context_handle_pointer is None:
return
out_buffers = None
try:
# ApplyControlToken fails with SEC_E_UNSUPPORTED_FUNCTION
# when called on Windows 7
if _win_version_info >= (6, 2):
buffers = new(secur32, 'SecBuffer[1]')
# This is a SCHANNEL_SHUTDOWN token (DWORD of 1)
buffers[0].cbBuffer = 4
buffers[0].BufferType = Secur32Const.SECBUFFER_TOKEN
buffers[0].pvBuffer = cast(secur32, 'BYTE *', buffer_from_bytes(b'\x01\x00\x00\x00'))
sec_buffer_desc_pointer = struct(secur32, 'SecBufferDesc')
sec_buffer_desc = unwrap(sec_buffer_desc_pointer)
sec_buffer_desc.ulVersion = Secur32Const.SECBUFFER_VERSION
sec_buffer_desc.cBuffers = 1
sec_buffer_desc.pBuffers = buffers
result = secur32.ApplyControlToken(self._context_handle_pointer, sec_buffer_desc_pointer)
handle_error(result, TLSError)
out_sec_buffer_desc_pointer, out_buffers = self._create_buffers(2)
out_buffers[0].BufferType = Secur32Const.SECBUFFER_TOKEN
out_buffers[1].BufferType = Secur32Const.SECBUFFER_ALERT
output_context_flags_pointer = new(secur32, 'ULONG *')
result = secur32.InitializeSecurityContextW(
self._session._credentials_handle,
self._context_handle_pointer,
self._hostname,
self._context_flags,
0,
0,
null(),
0,
null(),
out_sec_buffer_desc_pointer,
output_context_flags_pointer,
null()
)
acceptable_results = set([
Secur32Const.SEC_E_OK,
Secur32Const.SEC_E_CONTEXT_EXPIRED,
Secur32Const.SEC_I_CONTINUE_NEEDED
])
if result not in acceptable_results:
handle_error(result, TLSError)
token = bytes_from_buffer(out_buffers[0].pvBuffer, out_buffers[0].cbBuffer)
try:
# If there is an error sending the shutdown, ignore it since the
# connection is likely gone at this point
self._socket.send(token)
except (socket_.error):
pass
finally:
if out_buffers:
if not is_null(out_buffers[0].pvBuffer):
secur32.FreeContextBuffer(out_buffers[0].pvBuffer)
if not is_null(out_buffers[1].pvBuffer):
secur32.FreeContextBuffer(out_buffers[1].pvBuffer)
secur32.DeleteSecurityContext(self._context_handle_pointer)
self._context_handle_pointer = None
try:
self._socket.shutdown(socket_.SHUT_RDWR)
except (socket_.error):
pass
def close(self):
"""
Shuts down the TLS session and socket and forcibly closes it
"""
try:
self.shutdown()
finally:
if self._socket:
try:
self._socket.close()
except (socket_.error):
pass
self._socket = None
def _read_certificates(self):
"""
Reads end-entity and intermediate certificate information from the
TLS session
"""
cert_context_pointer_pointer = new(crypt32, 'CERT_CONTEXT **')
result = secur32.QueryContextAttributesW(
self._context_handle_pointer,
Secur32Const.SECPKG_ATTR_REMOTE_CERT_CONTEXT,
cert_context_pointer_pointer
)
handle_error(result, TLSError)
cert_context_pointer = unwrap(cert_context_pointer_pointer)
cert_context_pointer = cast(crypt32, 'CERT_CONTEXT *', cert_context_pointer)
cert_context = unwrap(cert_context_pointer)
cert_data = bytes_from_buffer(cert_context.pbCertEncoded, native(int, cert_context.cbCertEncoded))
self._certificate = Asn1Certificate.load(cert_data)
self._intermediates = []
store_handle = None
try:
store_handle = cert_context.hCertStore
context_pointer = crypt32.CertEnumCertificatesInStore(store_handle, null())
while not is_null(context_pointer):
context = unwrap(context_pointer)
data = bytes_from_buffer(context.pbCertEncoded, native(int, context.cbCertEncoded))
# The cert store seems to include the end-entity certificate as
# the last entry, but we already have that from the struct.
if data != cert_data:
self._intermediates.append(Asn1Certificate.load(data))
context_pointer = crypt32.CertEnumCertificatesInStore(store_handle, context_pointer)
finally:
if store_handle:
crypt32.CertCloseStore(store_handle, 0)
def _raise_closed(self):
"""
Raises an exception describing if the local or remote end closed the
connection
"""
if self._remote_closed:
raise TLSGracefulDisconnectError('The remote end closed the connection')
else:
raise TLSDisconnectError('The connection was already closed')
@property
def certificate(self):
"""
An asn1crypto.x509.Certificate object of the end-entity certificate
presented by the server
"""
if self._context_handle_pointer is None:
self._raise_closed()
if self._certificate is None:
self._read_certificates()
return self._certificate
@property
def intermediates(self):
"""
A list of asn1crypto.x509.Certificate objects that were presented as
intermediates by the server
"""
if self._context_handle_pointer is None:
self._raise_closed()
if self._certificate is None:
self._read_certificates()
return self._intermediates
@property
def cipher_suite(self):
"""
A unicode string of the IANA cipher suite name of the negotiated
cipher suite
"""
return self._cipher_suite
@property
def protocol(self):
"""
A unicode string of: "TLSv1.2", "TLSv1.1", "TLSv1", "SSLv3"
"""
return self._protocol
@property
def compression(self):
"""
A boolean if compression is enabled
"""
return self._compression
@property
def session_id(self):
"""
A unicode string of "new" or "reused" or None for no ticket
"""
return self._session_id
@property
def session_ticket(self):
"""
A unicode string of "new" or "reused" or None for no ticket
"""
return self._session_ticket
@property
def session(self):
"""
The oscrypto.tls.TLSSession object used for this connection
"""
return self._session
@property
def hostname(self):
"""
A unicode string of the TLS server domain name or IP address
"""
return self._hostname
@property
def port(self):
"""
An integer of the port number the socket is connected to
"""
return self.socket.getpeername()[1]
@property
def socket(self):
"""
The underlying socket.socket connection
"""
if self._context_handle_pointer is None:
self._raise_closed()
return self._socket
def __del__(self):
self.close()