Пример #1
0
    def send_message(self, data):
        """
        Write a block of data using the current cipher, as an SSH block.
        """
        # encrypt this sucka
        data = str(data)
        cmd = ord(data[0])
        if cmd in MSG_NAMES:
            cmd_name = MSG_NAMES[cmd]
        else:
            cmd_name = '$%x' % cmd
        orig_len = len(data)
        self.__write_lock.acquire()
        try:
            if self.__compress_engine_out is not None:
                data = self.__compress_engine_out(data)
            packet = self._build_packet(data)
            if self.__dump_packets:
                self._log(
                    DEBUG,
                    'Write packet <%s>, length %d' % (cmd_name, orig_len))
                self._log(DEBUG, util.format_binary(packet, 'OUT: '))
            if self.__block_engine_out != None:
                out = self.__block_engine_out.encrypt(packet)
            else:
                out = packet
            # + mac
            if self.__block_engine_out != None:
                payload = struct.pack('>I',
                                      self.__sequence_number_out) + packet
                out += compute_hmac(
                    self.__mac_key_out, payload,
                    self.__mac_engine_out)[:self.__mac_size_out]
            self.__sequence_number_out = (self.__sequence_number_out +
                                          1) & 0xffffffffL
            self.write_all(out)

            self.__sent_bytes += len(out)
            self.__sent_packets += 1
            if ((self.__sent_packets >= self.REKEY_PACKETS) or (self.__sent_bytes >= self.REKEY_BYTES)) \
                   and not self.__need_rekey:
                # 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:
            self.__write_lock.release()
Пример #2
0
 def _read_packet(self):
     x = self._read_all(4)
     # most sftp servers won't accept packets larger than about 32k, so
     # anything with the high byte set (> 16MB) is just garbage.
     if x[0] != '\x00':
         raise SFTPError('Garbage packet received')
     size = struct.unpack('>I', x)[0]
     data = self._read_all(size)
     if self.ultra_debug:
         self._log(DEBUG, util.format_binary(data, 'IN: '));
     if size > 0:
         t = ord(data[0])
         #self._log(DEBUG2, 'read: %s (len=%d)' % (CMD_NAMES.get(t), '0x%02x' % t, len(data)-1))
         return t, data[1:]
     return 0, ''
Пример #3
0
 def _read_packet(self):
     x = self._read_all(4)
     # most sftp servers won't accept packets larger than about 32k, so
     # anything with the high byte set (> 16MB) is just garbage.
     if x[0] != '\x00':
         raise SFTPError('Garbage packet received')
     size = struct.unpack('>I', x)[0]
     data = self._read_all(size)
     if self.ultra_debug:
         self._log(DEBUG, util.format_binary(data, 'IN: '))
     if size > 0:
         t = ord(data[0])
         #self._log(DEBUG2, 'read: %s (len=%d)' % (CMD_NAMES.get(t), '0x%02x' % t, len(data)-1))
         return t, data[1:]
     return 0, ''
Пример #4
0
    def send_message(self, data):
        """
        Write a block of data using the current cipher, as an SSH block.
        """
        # encrypt this sucka
        data = str(data)
        cmd = ord(data[0])
        if cmd in MSG_NAMES:
            cmd_name = MSG_NAMES[cmd]
        else:
            cmd_name = '$%x' % cmd
        orig_len = len(data)
        self.__write_lock.acquire()
        try:
            if self.__compress_engine_out is not None:
                data = self.__compress_engine_out(data)
            packet = self._build_packet(data)
            if self.__dump_packets:
                self._log(DEBUG, 'Write packet <%s>, length %d' % (cmd_name, orig_len))
                self._log(DEBUG, util.format_binary(packet, 'OUT: '))
            if self.__block_engine_out != None:
                out = self.__block_engine_out.encrypt(packet)
            else:
                out = packet
            # + mac
            if self.__block_engine_out != None:
                payload = struct.pack('>I', self.__sequence_number_out) + packet
                out += compute_hmac(self.__mac_key_out, payload, self.__mac_engine_out)[:self.__mac_size_out]
            self.__sequence_number_out = (self.__sequence_number_out + 1) & 0xffffffffL
            self.write_all(out)

            self.__sent_bytes += len(out)
            self.__sent_packets += 1
            if ((self.__sent_packets >= self.REKEY_PACKETS) or (self.__sent_bytes >= self.REKEY_BYTES)) \
                   and not self.__need_rekey:
                # 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:
            self.__write_lock.release()
Пример #5
0
    def read_message(self):
        """
        Only one thread should ever be in this function (no other locking is
        done).

        @raise SSHException: if the packet is mangled
        @raise NeedRekeyException: if the transport should rekey
        """
        header = self.read_all(self.__block_size_in, check_rekey=True)
        if self.__block_engine_in != None:
            header = self.__block_engine_in.decrypt(header)
        if self.__dump_packets:
            self._log(DEBUG, util.format_binary(header, 'IN: '));
        packet_size = struct.unpack('>I', header[:4])[0]
        # leftover contains decrypted bytes from the first block (after the length field)
        leftover = header[4:]
        if (packet_size - len(leftover)) % self.__block_size_in != 0:
            raise SSHException('Invalid packet blocking')
        buf = self.read_all(packet_size + self.__mac_size_in - len(leftover))
        packet = buf[:packet_size - len(leftover)]
        post_packet = buf[packet_size - len(leftover):]
        if self.__block_engine_in != None:
            packet = self.__block_engine_in.decrypt(packet)
        if self.__dump_packets:
            self._log(DEBUG, util.format_binary(packet, 'IN: '));
        packet = leftover + packet

        if self.__mac_size_in > 0:
            mac = post_packet[:self.__mac_size_in]
            mac_payload = struct.pack('>II', self.__sequence_number_in, packet_size) + packet
            my_mac = compute_hmac(self.__mac_key_in, mac_payload, self.__mac_engine_in)[:self.__mac_size_in]
            if my_mac != mac:
                raise SSHException('Mismatched MAC')
        padding = ord(packet[0])
        payload = packet[1:packet_size - padding]
        
        if self.__dump_packets:
            self._log(DEBUG, 'Got payload (%d bytes, %d padding)' % (packet_size, padding))

        if self.__compress_engine_in is not None:
            payload = self.__compress_engine_in(payload)

        msg = Message(payload[1:])
        msg.seqno = self.__sequence_number_in
        self.__sequence_number_in = (self.__sequence_number_in + 1) & 0xffffffffL

        # check for rekey
        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 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 >= 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()

        cmd = ord(payload[0])
        if cmd in MSG_NAMES:
            cmd_name = MSG_NAMES[cmd]
        else:
            cmd_name = '$%x' % cmd
        if self.__dump_packets:
            self._log(DEBUG, 'Read packet <%s>, length %d' % (cmd_name, len(payload)))
        return cmd, msg
Пример #6
0
 def _send_packet(self, t, packet):
     #self._log(DEBUG2, 'write: %s (len=%d)' % (CMD_NAMES.get(t, '0x%02x' % t), len(packet)))
     out = struct.pack('>I', len(packet) + 1) + chr(t) + packet
     if self.ultra_debug:
         self._log(DEBUG, util.format_binary(out, 'OUT: '))
     self._write_all(out)
Пример #7
0
    def read_message(self):
        """
        Only one thread should ever be in this function (no other locking is
        done).

        @raise SSHException: if the packet is mangled
        @raise NeedRekeyException: if the transport should rekey
        """
        header = self.read_all(self.__block_size_in, check_rekey=True)
        if self.__block_engine_in != None:
            header = self.__block_engine_in.decrypt(header)
        if self.__dump_packets:
            self._log(DEBUG, util.format_binary(header, 'IN: '))
        packet_size = struct.unpack('>I', header[:4])[0]
        # leftover contains decrypted bytes from the first block (after the length field)
        leftover = header[4:]
        if (packet_size - len(leftover)) % self.__block_size_in != 0:
            raise SSHException('Invalid packet blocking')
        buf = self.read_all(packet_size + self.__mac_size_in - len(leftover))
        packet = buf[:packet_size - len(leftover)]
        post_packet = buf[packet_size - len(leftover):]
        if self.__block_engine_in != None:
            packet = self.__block_engine_in.decrypt(packet)
        if self.__dump_packets:
            self._log(DEBUG, util.format_binary(packet, 'IN: '))
        packet = leftover + packet

        if self.__mac_size_in > 0:
            mac = post_packet[:self.__mac_size_in]
            mac_payload = struct.pack('>II', self.__sequence_number_in,
                                      packet_size) + packet
            my_mac = compute_hmac(self.__mac_key_in, mac_payload,
                                  self.__mac_engine_in)[:self.__mac_size_in]
            if my_mac != mac:
                raise SSHException('Mismatched MAC')
        padding = ord(packet[0])
        payload = packet[1:packet_size - padding]

        if self.__dump_packets:
            self._log(
                DEBUG,
                'Got payload (%d bytes, %d padding)' % (packet_size, padding))

        if self.__compress_engine_in is not None:
            payload = self.__compress_engine_in(payload)

        msg = Message(payload[1:])
        msg.seqno = self.__sequence_number_in
        self.__sequence_number_in = (self.__sequence_number_in +
                                     1) & 0xffffffffL

        # check for rekey
        self.__received_bytes += packet_size + self.__mac_size_in + 4
        self.__received_packets += 1
        if self.__need_rekey:
            # we've asked to rekey -- give them 20 packets to comply before
            # dropping the connection
            self.__received_packets_overflow += 1
            if self.__received_packets_overflow >= 20:
                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_packets_overflow = 0
            self._trigger_rekey()

        cmd = ord(payload[0])
        if cmd in MSG_NAMES:
            cmd_name = MSG_NAMES[cmd]
        else:
            cmd_name = '$%x' % cmd
        if self.__dump_packets:
            self._log(DEBUG,
                      'Read packet <%s>, length %d' % (cmd_name, len(payload)))
        return cmd, msg
Пример #8
0
 def _send_packet(self, t, packet):
     #self._log(DEBUG2, 'write: %s (len=%d)' % (CMD_NAMES.get(t, '0x%02x' % t), len(packet)))
     out = struct.pack('>I', len(packet) + 1) + chr(t) + packet
     if self.ultra_debug:
         self._log(DEBUG, util.format_binary(out, 'OUT: '))
     self._write_all(out)