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Your IP : 216.73.216.228
"""
"""
# Created on 2014.09.08
#
# Author: Giovanni Cannata
#
# Copyright 2014 - 2020 Giovanni Cannata
#
# This file is part of ldap3.
#
# ldap3 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 3 of the License, or
# (at your option) any later version.
#
# ldap3 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 ldap3 in the COPYING and COPYING.LESSER files.
# If not, see <http://www.gnu.org/licenses/>.
from string import hexdigits, ascii_letters, digits
from .. import SEQUENCE_TYPES
from ..core.exceptions import LDAPInvalidDnError
STATE_ANY = 0
STATE_ESCAPE = 1
STATE_ESCAPE_HEX = 2
def _add_ava(ava, decompose, remove_space, space_around_equal):
if not ava:
return ''
space = ' ' if space_around_equal else ''
attr_name, _, value = ava.partition('=')
if decompose:
if remove_space:
component = (attr_name.strip(), value.strip())
else:
component = (attr_name, value)
else:
if remove_space:
component = attr_name.strip() + space + '=' + space + value.strip()
else:
component = attr_name + space + '=' + space + value
return component
def to_dn(iterator, decompose=False, remove_space=False, space_around_equal=False, separate_rdn=False):
"""
Convert an iterator to a list of dn parts
if decompose=True return a list of tuple (one for each dn component) else return a list of strings
if remove_space=True removes unneeded spaces
if space_around_equal=True add spaces around equal in returned strings
if separate_rdn=True consider multiple RDNs as different component of DN
"""
dn = []
component = ''
escape_sequence = False
for c in iterator:
if c == '\\': # escape sequence
escape_sequence = True
elif escape_sequence and c != ' ':
escape_sequence = False
elif c == '+' and separate_rdn:
dn.append(_add_ava(component, decompose, remove_space, space_around_equal))
component = ''
continue
elif c == ',':
if '=' in component:
dn.append(_add_ava(component, decompose, remove_space, space_around_equal))
component = ''
continue
component += c
dn.append(_add_ava(component, decompose, remove_space, space_around_equal))
return dn
def _find_first_unescaped(dn, char, pos):
while True:
pos = dn.find(char, pos)
if pos == -1:
break # no char found
if pos > 0 and dn[pos - 1] != '\\': # unescaped char
break
elif pos > 1 and dn[pos - 1] == '\\': # may be unescaped
escaped = True
for c in dn[pos - 2:0:-1]:
if c == '\\':
escaped = not escaped
else:
break
if not escaped:
break
pos += 1
return pos
def _find_last_unescaped(dn, char, start, stop=0):
while True:
stop = dn.rfind(char, start, stop)
if stop == -1:
break
if stop >= 0 and dn[stop - 1] != '\\':
break
elif stop > 1 and dn[stop - 1] == '\\': # may be unescaped
escaped = True
for c in dn[stop - 2:0:-1]:
if c == '\\':
escaped = not escaped
else:
break
if not escaped:
break
if stop < start:
stop = -1
break
return stop
def _get_next_ava(dn):
comma = _find_first_unescaped(dn, ',', 0)
plus = _find_first_unescaped(dn, '+', 0)
if plus > 0 and (plus < comma or comma == -1):
equal = _find_first_unescaped(dn, '=', plus + 1)
if equal > plus + 1:
plus = _find_last_unescaped(dn, '+', plus, equal)
return dn[:plus], '+'
if comma > 0:
equal = _find_first_unescaped(dn, '=', comma + 1)
if equal > comma + 1:
comma = _find_last_unescaped(dn, ',', comma, equal)
return dn[:comma], ','
return dn, ''
def _split_ava(ava, escape=False, strip=True):
equal = ava.find('=')
while equal > 0: # not first character
if ava[equal - 1] != '\\': # not an escaped equal so it must be an ava separator
# attribute_type1 = ava[0:equal].strip() if strip else ava[0:equal]
if strip:
attribute_type = ava[0:equal].strip()
attribute_value = _escape_attribute_value(ava[equal + 1:].strip()) if escape else ava[equal + 1:].strip()
else:
attribute_type = ava[0:equal]
attribute_value = _escape_attribute_value(ava[equal + 1:]) if escape else ava[equal + 1:]
return attribute_type, attribute_value
equal = ava.find('=', equal + 1)
return '', (ava.strip if strip else ava) # if no equal found return only value
def _validate_attribute_type(attribute_type):
if not attribute_type:
raise LDAPInvalidDnError('attribute type not present')
if attribute_type == '<GUID': # patch for AD DirSync
return True
for c in attribute_type:
if not (c in ascii_letters or c in digits or c == '-'): # allowed uppercase and lowercase letters, digits and hyphen as per RFC 4512
raise LDAPInvalidDnError('character \'' + c + '\' not allowed in attribute type')
if attribute_type[0] in digits or attribute_type[0] == '-': # digits and hyphen not allowed as first character
raise LDAPInvalidDnError('character \'' + attribute_type[0] + '\' not allowed as first character of attribute type')
return True
def _validate_attribute_value(attribute_value):
if not attribute_value:
return False
if attribute_value[0] == '#': # only hex characters are valid
for c in attribute_value:
if c not in hexdigits: # allowed only hex digits as per RFC 4514
raise LDAPInvalidDnError('character ' + c + ' not allowed in hex representation of attribute value')
if len(attribute_value) % 2 == 0: # string must be # + HEX HEX (an odd number of chars)
raise LDAPInvalidDnError('hex representation must be in the form of <HEX><HEX> pairs')
if attribute_value[0] == ' ': # unescaped space cannot be used as leading or last character
raise LDAPInvalidDnError('SPACE must be escaped as leading character of attribute value')
if attribute_value.endswith(' ') and not attribute_value.endswith('\\ '):
raise LDAPInvalidDnError('SPACE must be escaped as trailing character of attribute value')
state = STATE_ANY
for c in attribute_value:
if state == STATE_ANY:
if c == '\\':
state = STATE_ESCAPE
elif c in '"#+,;<=>\00':
raise LDAPInvalidDnError('special character ' + c + ' must be escaped')
elif state == STATE_ESCAPE:
if c in hexdigits:
state = STATE_ESCAPE_HEX
elif c in ' "#+,;<=>\\\00':
state = STATE_ANY
else:
raise LDAPInvalidDnError('invalid escaped character ' + c)
elif state == STATE_ESCAPE_HEX:
if c in hexdigits:
state = STATE_ANY
else:
raise LDAPInvalidDnError('invalid escaped character ' + c)
# final state
if state != STATE_ANY:
raise LDAPInvalidDnError('invalid final character')
return True
def _escape_attribute_value(attribute_value):
if not attribute_value:
return ''
if attribute_value[0] == '#': # with leading SHARP only pairs of hex characters are valid
valid_hex = True
if len(attribute_value) % 2 == 0: # string must be # + HEX HEX (an odd number of chars)
valid_hex = False
if valid_hex:
for c in attribute_value:
if c not in hexdigits: # allowed only hex digits as per RFC 4514
valid_hex = False
break
if valid_hex:
return attribute_value
state = STATE_ANY
escaped = ''
tmp_buffer = ''
for c in attribute_value:
if state == STATE_ANY:
if c == '\\':
state = STATE_ESCAPE
elif c in '"#+,;<=>\00':
escaped += '\\' + c
else:
escaped += c
elif state == STATE_ESCAPE:
if c in hexdigits:
tmp_buffer = c
state = STATE_ESCAPE_HEX
elif c in ' "#+,;<=>\\\00':
escaped += '\\' + c
state = STATE_ANY
else:
escaped += '\\\\' + c
elif state == STATE_ESCAPE_HEX:
if c in hexdigits:
escaped += '\\' + tmp_buffer + c
else:
escaped += '\\\\' + tmp_buffer + c
tmp_buffer = ''
state = STATE_ANY
# final state
if state == STATE_ESCAPE:
escaped += '\\\\'
elif state == STATE_ESCAPE_HEX:
escaped += '\\\\' + tmp_buffer
if escaped[0] == ' ': # leading SPACE must be escaped
escaped = '\\' + escaped
if escaped[-1] == ' ' and len(escaped) > 1 and escaped[-2] != '\\': # trailing SPACE must be escaped
escaped = escaped[:-1] + '\\ '
return escaped
def parse_dn(dn, escape=False, strip=False):
"""
Parses a DN into syntactic components
:param dn:
:param escape:
:param strip:
:return:
a list of tripels representing `attributeTypeAndValue` elements
containing `attributeType`, `attributeValue` and the following separator (`COMMA` or `PLUS`) if given, else an empty `str`.
in their original representation, still containing escapes or encoded as hex.
"""
rdns = []
avas = []
while dn:
ava, separator = _get_next_ava(dn) # if returned ava doesn't containg any unescaped equal it'a appended to last ava in avas
dn = dn[len(ava) + 1:]
if _find_first_unescaped(ava, '=', 0) > 0 or len(avas) == 0:
avas.append((ava, separator))
else:
avas[len(avas) - 1] = (avas[len(avas) - 1][0] + avas[len(avas) - 1][1] + ava, separator)
for ava, separator in avas:
attribute_type, attribute_value = _split_ava(ava, escape, strip)
if not _validate_attribute_type(attribute_type):
raise LDAPInvalidDnError('unable to validate attribute type in ' + ava)
if not _validate_attribute_value(attribute_value):
raise LDAPInvalidDnError('unable to validate attribute value in ' + ava)
rdns.append((attribute_type, attribute_value, separator))
dn = dn[len(ava) + 1:]
if not rdns:
raise LDAPInvalidDnError('empty dn')
return rdns
def safe_dn(dn, decompose=False, reverse=False):
"""
normalize and escape a dn, if dn is a sequence it is joined.
the reverse parameter changes the join direction of the sequence
"""
if isinstance(dn, SEQUENCE_TYPES):
components = [rdn for rdn in dn]
if reverse:
dn = ','.join(reversed(components))
else:
dn = ','.join(components)
if decompose:
escaped_dn = []
else:
escaped_dn = ''
if dn.startswith('<GUID=') and dn.endswith('>'): # Active Directory allows looking up objects by putting its GUID in a specially-formatted DN (e.g. '<GUID=7b95f0d5-a3ed-486c-919c-077b8c9731f2>')
escaped_dn = dn
elif dn.startswith('<WKGUID=') and dn.endswith('>'): # Active Directory allows Binding to Well-Known Objects Using WKGUID in a specially-formatted DN (e.g. <WKGUID=a9d1ca15768811d1aded00c04fd8d5cd,dc=Fabrikam,dc=com>)
escaped_dn = dn
elif dn.startswith('<SID=') and dn.endswith('>'): # Active Directory allows looking up objects by putting its security identifier (SID) in a specially-formatted DN (e.g. '<SID=S-#-#-##-##########-##########-##########-######>')
escaped_dn = dn
elif '@' not in dn: # active directory UPN (User Principal Name) consist of an account, the at sign (@) and a domain, or the domain level logn name domain\username
for component in parse_dn(dn, escape=True):
if decompose:
escaped_dn.append((component[0], component[1], component[2]))
else:
escaped_dn += component[0] + '=' + component[1] + component[2]
elif '@' in dn and '=' not in dn and len(dn.split('@')) != 2:
raise LDAPInvalidDnError('Active Directory User Principal Name must consist of name@domain')
elif '\\' in dn and '=' not in dn and len(dn.split('\\')) != 2:
raise LDAPInvalidDnError('Active Directory Domain Level Logon Name must consist of name\\domain')
else:
escaped_dn = dn
return escaped_dn
def safe_rdn(dn, decompose=False):
"""Returns a list of rdn for the dn, usually there is only one rdn, but it can be more than one when the + sign is used"""
escaped_rdn = []
one_more = True
for component in parse_dn(dn, escape=True):
if component[2] == '+' or one_more:
if decompose:
escaped_rdn.append((component[0], component[1]))
else:
escaped_rdn.append(component[0] + '=' + component[1])
if component[2] == '+':
one_more = True
else:
one_more = False
break
if one_more:
raise LDAPInvalidDnError('bad dn ' + str(dn))
return escaped_rdn
def escape_rdn(rdn):
"""
Escape rdn characters to prevent injection according to RFC 4514.
"""
# '/' must be handled first or the escape slashes will be escaped!
for char in ['\\', ',', '+', '"', '<', '>', ';', '=', '\x00']:
rdn = rdn.replace(char, '\\' + char)
if rdn[0] == '#' or rdn[0] == ' ':
rdn = ''.join(('\\', rdn))
if rdn[-1] == ' ':
rdn = ''.join((rdn[:-1], '\\ '))
return rdn