dorian
/
paramiko
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Merge #63

This commit is contained in:
Jeff Forcier 2012-05-16 15:51:27 -07:00
parent 7bcbc24198
commit a6358f8d13
1 changed files with 15 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
paramiko/packet.py
View File

@ -57,8 +57,11 @@ class Packetizer (object):
# READ the secsh RFC's before raising these values. if anything,
# they should probably be lower.
REKEY_PACKETS = pow(2, 30)
REKEY_BYTES = pow(2, 30)
REKEY_PACKETS = pow(2, 29)
REKEY_BYTES = pow(2, 29)
REKEY_PACKETS_OVERFLOW_MAX = pow(2,29) # Allow receiving this many packets after a re-key request before terminating
REKEY_BYTES_OVERFLOW_MAX = pow(2,29) # Allow receiving this many bytes after a re-key request before terminating
def __init__(self, socket):
self.__socket = socket
@ -74,6 +77,7 @@ class Packetizer (object):
self.__sent_packets = 0
self.__received_bytes = 0
self.__received_packets = 0
self.__received_bytes_overflow = 0
self.__received_packets_overflow = 0
# current inbound/outbound ciphering:
@ -134,6 +138,7 @@ class Packetizer (object):
self.__mac_key_in = mac_key
self.__received_bytes = 0
self.__received_packets = 0
self.__received_bytes_overflow = 0
self.__received_packets_overflow = 0
# wait until the reset happens in both directions before clearing rekey flag
self.__init_count |= 2
@ -316,6 +321,7 @@ class Packetizer (object):
# only ask once for rekeying
self._log(DEBUG, 'Rekeying (hit %d packets, %d bytes sent)' %
(self.__sent_packets, self.__sent_bytes))
self.__received_bytes_overflow = 0
self.__received_packets_overflow = 0
self._trigger_rekey()
finally:
@ -368,19 +374,23 @@ class Packetizer (object):
self.__sequence_number_in = (self.__sequence_number_in + 1) & 0xffffffffL
# check for rekey
self.__received_bytes += packet_size + self.__mac_size_in + 4
raw_packet_size = packet_size + self.__mac_size_in + 4
self.__received_bytes += raw_packet_size
self.__received_packets += 1
if self.__need_rekey:
# we've asked to rekey -- give them 20 packets to comply before
# we've asked to rekey -- give them some packets to comply before
# dropping the connection
self.__received_bytes_overflow += raw_packet_size
self.__received_packets_overflow += 1
if self.__received_packets_overflow >= 20:
if (self.__received_packets_overflow >= self.REKEY_PACKETS_OVERFLOW_MAX) or \
(self.__received_bytes_overflow >= self.REKEY_BYTES_OVERFLOW_MAX):
raise SSHException('Remote transport is ignoring rekey requests')
elif (self.__received_packets >= self.REKEY_PACKETS) or \
(self.__received_bytes >= self.REKEY_BYTES):
# only ask once for rekeying
self._log(DEBUG, 'Rekeying (hit %d packets, %d bytes received)' %
(self.__received_packets, self.__received_bytes))
self.__received_bytes_overflow = 0
self.__received_packets_overflow = 0
self._trigger_rekey()