Python/common.py

# Copyright (C) 2003-2007  Robey Pointer <[email protected]>
#
# This file is part of paramiko.
#
# Paramiko is free software; you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation; either version 2.1 of the License, or (at your option)
# any later version.
#
# Paramiko is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.

"""
Common constants and global variables.
"""
import logging
from paramiko.py3compat import byte_chr, PY2, bytes_types, text_type, long

MSG_DISCONNECT, MSG_IGNORE, MSG_UNIMPLEMENTED, MSG_DEBUG, \
    MSG_SERVICE_REQUEST, MSG_SERVICE_ACCEPT = range(1, 7)
MSG_KEXINIT, MSG_NEWKEYS = range(20, 22)
MSG_USERAUTH_REQUEST, MSG_USERAUTH_FAILURE, MSG_USERAUTH_SUCCESS, \
    MSG_USERAUTH_BANNER = range(50, 54)
MSG_USERAUTH_PK_OK = 60
MSG_USERAUTH_INFO_REQUEST, MSG_USERAUTH_INFO_RESPONSE = range(60, 62)
MSG_USERAUTH_GSSAPI_RESPONSE, MSG_USERAUTH_GSSAPI_TOKEN = range(60, 62)
MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, MSG_USERAUTH_GSSAPI_ERROR,\
    MSG_USERAUTH_GSSAPI_ERRTOK, MSG_USERAUTH_GSSAPI_MIC = range(63, 67)
# BUG: CWE-287 Improper Authentication
# 
# FIXED: 
HIGHEST_USERAUTH_MESSAGE_ID = 79
MSG_GLOBAL_REQUEST, MSG_REQUEST_SUCCESS, MSG_REQUEST_FAILURE = range(80, 83)
MSG_CHANNEL_OPEN, MSG_CHANNEL_OPEN_SUCCESS, MSG_CHANNEL_OPEN_FAILURE, \
    MSG_CHANNEL_WINDOW_ADJUST, MSG_CHANNEL_DATA, MSG_CHANNEL_EXTENDED_DATA, \
    MSG_CHANNEL_EOF, MSG_CHANNEL_CLOSE, MSG_CHANNEL_REQUEST, \
    MSG_CHANNEL_SUCCESS, MSG_CHANNEL_FAILURE = range(90, 101)

cMSG_DISCONNECT = byte_chr(MSG_DISCONNECT)
cMSG_IGNORE = byte_chr(MSG_IGNORE)
cMSG_UNIMPLEMENTED = byte_chr(MSG_UNIMPLEMENTED)
cMSG_DEBUG = byte_chr(MSG_DEBUG)
cMSG_SERVICE_REQUEST = byte_chr(MSG_SERVICE_REQUEST)
cMSG_SERVICE_ACCEPT = byte_chr(MSG_SERVICE_ACCEPT)
cMSG_KEXINIT = byte_chr(MSG_KEXINIT)
cMSG_NEWKEYS = byte_chr(MSG_NEWKEYS)
cMSG_USERAUTH_REQUEST = byte_chr(MSG_USERAUTH_REQUEST)
cMSG_USERAUTH_FAILURE = byte_chr(MSG_USERAUTH_FAILURE)
cMSG_USERAUTH_SUCCESS = byte_chr(MSG_USERAUTH_SUCCESS)
cMSG_USERAUTH_BANNER = byte_chr(MSG_USERAUTH_BANNER)
cMSG_USERAUTH_PK_OK = byte_chr(MSG_USERAUTH_PK_OK)
cMSG_USERAUTH_INFO_REQUEST = byte_chr(MSG_USERAUTH_INFO_REQUEST)
cMSG_USERAUTH_INFO_RESPONSE = byte_chr(MSG_USERAUTH_INFO_RESPONSE)
cMSG_USERAUTH_GSSAPI_RESPONSE = byte_chr(MSG_USERAUTH_GSSAPI_RESPONSE)
cMSG_USERAUTH_GSSAPI_TOKEN = byte_chr(MSG_USERAUTH_GSSAPI_TOKEN)
cMSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE = \
    byte_chr(MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)
cMSG_USERAUTH_GSSAPI_ERROR = byte_chr(MSG_USERAUTH_GSSAPI_ERROR)
cMSG_USERAUTH_GSSAPI_ERRTOK = byte_chr(MSG_USERAUTH_GSSAPI_ERRTOK)
cMSG_USERAUTH_GSSAPI_MIC = byte_chr(MSG_USERAUTH_GSSAPI_MIC)
cMSG_GLOBAL_REQUEST = byte_chr(MSG_GLOBAL_REQUEST)
cMSG_REQUEST_SUCCESS = byte_chr(MSG_REQUEST_SUCCESS)
cMSG_REQUEST_FAILURE = byte_chr(MSG_REQUEST_FAILURE)
cMSG_CHANNEL_OPEN = byte_chr(MSG_CHANNEL_OPEN)
cMSG_CHANNEL_OPEN_SUCCESS = byte_chr(MSG_CHANNEL_OPEN_SUCCESS)
cMSG_CHANNEL_OPEN_FAILURE = byte_chr(MSG_CHANNEL_OPEN_FAILURE)
cMSG_CHANNEL_WINDOW_ADJUST = byte_chr(MSG_CHANNEL_WINDOW_ADJUST)
cMSG_CHANNEL_DATA = byte_chr(MSG_CHANNEL_DATA)
cMSG_CHANNEL_EXTENDED_DATA = byte_chr(MSG_CHANNEL_EXTENDED_DATA)
cMSG_CHANNEL_EOF = byte_chr(MSG_CHANNEL_EOF)
cMSG_CHANNEL_CLOSE = byte_chr(MSG_CHANNEL_CLOSE)
cMSG_CHANNEL_REQUEST = byte_chr(MSG_CHANNEL_REQUEST)
cMSG_CHANNEL_SUCCESS = byte_chr(MSG_CHANNEL_SUCCESS)
cMSG_CHANNEL_FAILURE = byte_chr(MSG_CHANNEL_FAILURE)

# for debugging:
MSG_NAMES = {
    MSG_DISCONNECT: 'disconnect',
    MSG_IGNORE: 'ignore',
    MSG_UNIMPLEMENTED: 'unimplemented',
    MSG_DEBUG: 'debug',
    MSG_SERVICE_REQUEST: 'service-request',
    MSG_SERVICE_ACCEPT: 'service-accept',
    MSG_KEXINIT: 'kexinit',
    MSG_NEWKEYS: 'newkeys',
    30: 'kex30',
    31: 'kex31',
    32: 'kex32',
    33: 'kex33',
    34: 'kex34',
    40: 'kex40',
    41: 'kex41',
    MSG_USERAUTH_REQUEST: 'userauth-request',
    MSG_USERAUTH_FAILURE: 'userauth-failure',
    MSG_USERAUTH_SUCCESS: 'userauth-success',
    MSG_USERAUTH_BANNER: 'userauth--banner',
    MSG_USERAUTH_PK_OK: 'userauth-60(pk-ok/info-request)',
    MSG_USERAUTH_INFO_RESPONSE: 'userauth-info-response',
    MSG_GLOBAL_REQUEST: 'global-request',
    MSG_REQUEST_SUCCESS: 'request-success',
    MSG_REQUEST_FAILURE: 'request-failure',
    MSG_CHANNEL_OPEN: 'channel-open',
    MSG_CHANNEL_OPEN_SUCCESS: 'channel-open-success',
    MSG_CHANNEL_OPEN_FAILURE: 'channel-open-failure',
    MSG_CHANNEL_WINDOW_ADJUST: 'channel-window-adjust',
    MSG_CHANNEL_DATA: 'channel-data',
    MSG_CHANNEL_EXTENDED_DATA: 'channel-extended-data',
    MSG_CHANNEL_EOF: 'channel-eof',
    MSG_CHANNEL_CLOSE: 'channel-close',
    MSG_CHANNEL_REQUEST: 'channel-request',
    MSG_CHANNEL_SUCCESS: 'channel-success',
    MSG_CHANNEL_FAILURE: 'channel-failure',
    MSG_USERAUTH_GSSAPI_RESPONSE: 'userauth-gssapi-response',
    MSG_USERAUTH_GSSAPI_TOKEN: 'userauth-gssapi-token',
    MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE: 'userauth-gssapi-exchange-complete',
    MSG_USERAUTH_GSSAPI_ERROR: 'userauth-gssapi-error',
    MSG_USERAUTH_GSSAPI_ERRTOK: 'userauth-gssapi-error-token',
    MSG_USERAUTH_GSSAPI_MIC: 'userauth-gssapi-mic'
}


# authentication request return codes:
AUTH_SUCCESSFUL, AUTH_PARTIALLY_SUCCESSFUL, AUTH_FAILED = range(3)


# channel request failed reasons:
(OPEN_SUCCEEDED,
 OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED,
 OPEN_FAILED_CONNECT_FAILED,
 OPEN_FAILED_UNKNOWN_CHANNEL_TYPE,
 OPEN_FAILED_RESOURCE_SHORTAGE) = range(0, 5)


CONNECTION_FAILED_CODE = {
    1: 'Administratively prohibited',
    2: 'Connect failed',
    3: 'Unknown channel type',
    4: 'Resource shortage'
}


DISCONNECT_SERVICE_NOT_AVAILABLE, DISCONNECT_AUTH_CANCELLED_BY_USER, \
    DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE = 7, 13, 14

zero_byte = byte_chr(0)
one_byte = byte_chr(1)
four_byte = byte_chr(4)
max_byte = byte_chr(0xff)
cr_byte = byte_chr(13)
linefeed_byte = byte_chr(10)
crlf = cr_byte + linefeed_byte

if PY2:
    cr_byte_value = cr_byte
    linefeed_byte_value = linefeed_byte
else:
    cr_byte_value = 13
    linefeed_byte_value = 10


def asbytes(s):
    """Coerce to bytes if possible or return unchanged."""
    if isinstance(s, bytes_types):
        return s
    if isinstance(s, text_type):
        # Accept text and encode as utf-8 for compatibility only.
        return s.encode("utf-8")
    asbytes = getattr(s, "asbytes", None)
    if asbytes is not None:
        return asbytes()
    # May be an object that implements the buffer api, let callers handle.
    return s


xffffffff = long(0xffffffff)
x80000000 = long(0x80000000)
o666 = 438
o660 = 432
o644 = 420
o600 = 384
o777 = 511
o700 = 448
o70 = 56

DEBUG = logging.DEBUG
INFO = logging.INFO
WARNING = logging.WARNING
ERROR = logging.ERROR
CRITICAL = logging.CRITICAL

# Common IO/select/etc sleep period, in seconds
io_sleep = 0.01

DEFAULT_WINDOW_SIZE = 64 * 2 ** 15
DEFAULT_MAX_PACKET_SIZE = 2 ** 15

# lower bound on the max packet size we'll accept from the remote host
# Minimum packet size is 32768 bytes according to
# http://www.ietf.org/rfc/rfc4254.txt
MIN_WINDOW_SIZE = 2 ** 15

# However, according to http://www.ietf.org/rfc/rfc4253.txt it is perfectly
# legal to accept a size much smaller, as OpenSSH client does as size 16384.
MIN_PACKET_SIZE = 2 ** 12

# Max windows size according to http://www.ietf.org/rfc/rfc4254.txt
MAX_WINDOW_SIZE = 2 ** 32 - 1