class Handshake(pypacker.Packet):
__hdr__ = (("type", "B", 0), ("len", "3s", b"\x00" * 3))
len_i = pypacker.get_property_bytes_num("len", ">I")
def extract_certificates(self):
"""
Extracts certificates from a Handshake packet
Workflow:
find 1# cert segment(SSL.get_cert_length()) -> collect/assemble until
cert length collected -> create SSL(tcp_bytes) -> ssl.handshake.extract_certs()
return -- [cert1, cert2, ...]
"""
ret = []
if self.type != HNDS_CERTIFICATE:
logger.warning("not a certificate handshake: %r", self)
return ret
bts_body = self.body_bytes
certs_len = self.len_i - 3
#logger.debug("total cert length: %d", certs_len)
# skip total cert length
off = 3
while off < certs_len:
cert_len = unpack_I(b"\x00" + bts_body[off:off + 3])[0]
#logger.debug("cert length: %d", cert_len)
cert_bytes = bts_body[off + 3:off + 3 + cert_len]
off += 3 + cert_len
ret.append(cert_bytes)
return ret
class serverHandshakeHello(pypacker.Packet):
__hdr__ = (
("type", "B", 0),
("len", "3s", b"\x00" * 3),
("tlsversion", "H", 0x0301),
("random", "32s", b"\x00" * 32),
("sid_len", "B", 32),
("sid", None, triggerlist.TriggerList), #var length
# ("cipsuite_len", "H", 0x0032),
("ciphersuite", None, triggerlist.TriggerList), #var length
# ("compr_len", "B", 0),
("compression", "B", 0),
("ext_len", "H", 0x0000),
("extensions", None, triggerlist.TriggerList),
)
len_i = pypacker.get_property_bytes_num("len", ">I")
@staticmethod
def __parse_extension(buf):
extensions = []
offset = 0
buflen = len(buf)
while offset < buflen:
ext_content_len = struct.unpack('!h',
buf[offset + 2:offset + 4])[0]
ext_len = 4 + ext_content_len
extensions.append(Extension(buf[offset:offset + ext_len]))
offset += ext_len
return extensions
def _dissect(self, buf):
sid_len = buf[38]
offset = 38 + 1
sid = buf[offset:offset + sid_len]
self.sid.append(sid)
offset = offset + sid_len
#the next few lines are just to bypass some stuff that isn't there in my testing so far, but left, just in case for cleanup later
# cipsuite_len = struct.unpack('!h',buf[offset:offset+2])[0]
cipsuite_len = 2 #test for now
# offset = offset + 2
ciphersuite = buf[offset:offset + cipsuite_len]
self.ciphersuite.append(ciphersuite)
offset = offset + cipsuite_len + 1
ext_len = struct.unpack('!h', buf[offset:offset + 2])[0]
offset = offset + 2
self._init_triggerlist("extensions", buf[offset:],
self.__parse_extension)
offset = offset + ext_len
return len(buf)
class clientHandshakeHello(pypacker.Packet):
__hdr__ = (
("type", "B", 0),
("len", "3s", b"\x00" * 3),
("tlsversion", "H", 0x0301),
("random", "32s", b"\x00" * 32),
("sid_len", "B", 32),
("sid", None, triggerlist.TriggerList), #var length
("cipsuite_len", "H", 0x0032),
("ciphersuite", None, triggerlist.TriggerList), #var length
("compr_len", "B", 0),
("compression", "B", 0),
("ext_len", "H", 0x0000),
("extensions", None, triggerlist.TriggerList),
)
len_i = pypacker.get_property_bytes_num("len", ">I")
@staticmethod
def __parse_extension(buf):
extensions = []
offset = 0
buflen = len(buf)
while offset < buflen:
ext_content_len = struct.unpack('!h',
buf[offset + 2:offset + 4])[0]
ext_len = 4 + ext_content_len
extensions.append(Extension(buf[offset:offset + ext_len]))
offset += ext_len
return extensions
def _dissect(self, buf):
sid_len = buf[38]
offset = 38 + 1
sid = buf[offset:offset + sid_len]
self.sid.append(sid)
offset = offset + sid_len
cipsuite_len = struct.unpack('!h', buf[offset:offset + 2])[0]
offset = offset + 2
ciphersuite = buf[offset:offset + cipsuite_len]
self.ciphersuite.append(ciphersuite)
offset = offset + cipsuite_len + 2
ext_len = struct.unpack('!h', buf[offset:offset + 2])[0]
offset = offset + 2
self._init_triggerlist("extensions", buf[offset:],
self.__parse_extension)
offset = offset + ext_len
return len(buf)
class HandshakeHello(pypacker.Packet):
__hdr__ = (
("type", "B", 0),
# can't use struct here but:
# int.from_bytes(len, "big")
("len", "3s", b"\x00" * 3),
("tlsversion", "H", 0x0301),
("random", "32s", b"\x00" * 32),
("sid_len", "B", 32),
# variable length
("sid", None, b"A" * 32),
("ciphersuite", "H", 0x0035),
("compression", "B", 0),
("ext_len", "H", 0x0000),
("extensions", None, triggerlist.TriggerList),
)
len_i = pypacker.get_property_bytes_num("len", ">I")
@staticmethod
def __parse_extension(buf):
extensions = []
offset = 0
buflen = len(buf)
while offset < buflen:
ext_content_len = unpack_H(buf[offset + 2:offset + 4])[0]
ext_len = 4 + ext_content_len
extensions.append(Extension(buf[offset:offset + ext_len]))
offset += ext_len
return extensions
def _dissect(self, buf):
sid_len = buf[38]
offset_extlen = 38 + sid_len + 3
# ext_len = unpack_H(buf[offset_extlen : offset_extlen+2])
self._init_triggerlist("extensions", buf[offset_extlen + 2:],
self.__parse_extension)
