Source code for windows.crypto.cryptmsg
import ctypes
from windows import winproxy
import windows.generated_def as gdef
import windows.crypto
[docs]
class CryptMessage(gdef.HCRYPTMSG):
"""Represent a PKCS #7 message
(see `Low-level Message Functions <https://msdn.microsoft.com/en-us/library/windows/desktop/aa380252(v=vs.85).aspx#low_level_message_functions>`_)
"""
MSG_PARAM_KNOW_TYPES = {gdef.CMSG_SIGNER_INFO_PARAM: gdef.CMSG_SIGNER_INFO,
gdef.CMSG_SIGNER_COUNT_PARAM: gdef.DWORD,
gdef.CMSG_CERT_COUNT_PARAM: gdef.DWORD,
gdef.CMSG_ENVELOPE_ALGORITHM_PARAM: gdef.CRYPT_ALGORITHM_IDENTIFIER,
gdef.CMSG_RECIPIENT_COUNT_PARAM: gdef.DWORD,
gdef.CMSG_RECIPIENT_INFO_PARAM: gdef.CERT_INFO,
}
def get_param(self, param_type, index=0, raw=False):
data_size = gdef.DWORD()
# https://msdn.microsoft.com/en-us/library/windows/desktop/aa380227(v=vs.85).aspx
winproxy.CryptMsgGetParam(self, param_type, index, None, data_size)
buffer = ctypes.c_buffer(data_size.value)
winproxy.CryptMsgGetParam(self, param_type, index, buffer, data_size)
if raw:
return (buffer, data_size)
if param_type in self.MSG_PARAM_KNOW_TYPES:
buffer = self.MSG_PARAM_KNOW_TYPES[param_type].from_buffer(buffer)
if isinstance(buffer, gdef.DWORD): # DWORD -> return the Python int
return buffer.value
return buffer
# Certificate accessors
@property
def nb_cert(self):
"""The number of certificate embded in the :class:`CryptObject`
:type: :class:`int`
"""
return self.get_param(gdef.CMSG_CERT_COUNT_PARAM)
def get_raw_cert(self, index=0):
return self.get_param(gdef.CMSG_CERT_PARAM, index)
[docs]
def get_cert(self, index=0):
"""Return embded :class:`Certificate` number ``index``.
.. note::
Not all embded certificate are directly used to sign the :class:`CryptObject`.
"""
return windows.crypto.Certificate.from_buffer(self.get_raw_cert(index))
@property
def certs(self):
"""The list of :class:`Certificate` embded in the message"""
return [self.get_cert(i) for i in range(self.nb_cert)]
# Signers accessors
@property
def nb_signer(self):
"""The number of signers for the CryptObject
:type: :class:`int`
"""
try:
return self.get_param(gdef.CMSG_SIGNER_COUNT_PARAM)
except WindowsError as e:
if (e.winerror & 0xffffffff) == gdef.CRYPT_E_INVALID_MSG_TYPE:
return 0
raise
[docs]
def get_signer_data(self, index=0):
"""Returns the signer informations for signer nb ``index``
:return: :class:`~windows.generated_def.winstructs.CMSG_SIGNER_INFO`
"""
return self.get_param(gdef.CMSG_SIGNER_INFO_PARAM, index)
@property
def signers(self):
"""The list of :class:`~windows.generated_def.winstructs.CMSG_SIGNER_INFO` embed in the message"""
return [self.get_signer_data(i) for i in range(self.nb_signer)]
@property
def nb_recipient(self):
"""TODO: DOC"""
return self.get_param(gdef.CMSG_RECIPIENT_COUNT_PARAM)
[docs]
def get_recipient_data(self, index=0):
"""TODO: DOC"""
return self.get_param(gdef.CMSG_RECIPIENT_INFO_PARAM, index)
@property
def recipients(self):
"""TODO: DOC"""
return [self.get_recipient_data(i) for i in range(self.nb_recipient)]
@property
def content(self):
return self.get_param(gdef.CMSG_CONTENT_PARAM)[:]
@property
def content_type(self):
data = self.get_param(gdef.CMSG_INNER_CONTENT_TYPE_PARAM)
assert data[-1] == "\x00", "CMSG_INNER_CONTENT_TYPE_PARAM not NULL TERMINATED"
return data[:-1]
def update(self, blob, final):
# Test isinstance string ?
if isinstance(blob, (windows.pycompat.anybuff, bytearray)):
blob = windows.pycompat.raw_encode(blob)
buffer = windows.utils.BUFFER(gdef.BYTE).from_buffer_copy(blob)
return winproxy.CryptMsgUpdate(self, buffer, len(blob), final)
return winproxy.CryptMsgUpdate(self, blob.pbData, blob.cbData, final)
# constructor
[docs]
@classmethod
def from_buffer(self, data):
hmsg = winproxy.CryptMsgOpenToDecode(windows.crypto.DEFAULT_ENCODING, 0, 0, None, None, None)
newmsg = CryptMessage(hmsg)
newmsg.update(data, final=True)
return newmsg
def __del__(self):
return winproxy.CryptMsgClose(self)