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- """
- """
-
- # Created on 2014.09.08
- #
- # Author: Giovanni Cannata
- #
- # Copyright 2014 - 2018 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
-
- 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
-
- 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] == ' ': # space cannot be used as first or last character
- raise LDAPInvalidDnError('SPACE not allowed as first character of attribute value')
- if attribute_value[-1] == ' ':
- raise LDAPInvalidDnError('SPACE not allowed as last 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 characters ' + 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=True):
- 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 '@' not in dn and '\\' 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
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