forked from ruby-ldap/ruby-net-ldap
/
filter.rb
494 lines (448 loc) · 16.2 KB
/
filter.rb
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
# Copyright (C) 2006 by Francis Cianfrocca. All Rights Reserved.
#
# Gmail: garbagecat10
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#
#---------------------------------------------------------------------------
#
#
require 'strscan'
module Net
class LDAP
# Class Net::LDAP::Filter is used to constrain
# LDAP searches. An object of this class is
# passed to Net::LDAP#search in the parameter :filter.
#
# Net::LDAP::Filter supports the complete set of search filters
# available in LDAP, including conjunction, disjunction and negation
# (AND, OR, and NOT). This class supplants the (infamous) RFC-2254
# standard notation for specifying LDAP search filters.
#
# Here's how to code the familiar "objectclass is present" filter:
# f = Net::LDAP::Filter.pres( "objectclass" )
# The object returned by this code can be passed directly to
# the <tt>:filter</tt> parameter of Net::LDAP#search.
#
# See the individual class and instance methods below for more examples.
#
class Filter
def initialize op, a, b
@op = op
@left = a
@right = b
end
# #eq creates a filter object indicating that the value of
# a paticular attribute must be either <i>present</i> or must
# match a particular string.
#
# To specify that an attribute is "present" means that only
# directory entries which contain a value for the particular
# attribute will be selected by the filter. This is useful
# in case of optional attributes such as <tt>mail.</tt>
# Presence is indicated by giving the value "*" in the second
# parameter to #eq. This example selects only entries that have
# one or more values for <tt>sAMAccountName:</tt>
# f = Net::LDAP::Filter.eq( "sAMAccountName", "*" )
#
# To match a particular range of values, pass a string as the
# second parameter to #eq. The string may contain one or more
# "*" characters as wildcards: these match zero or more occurrences
# of any character. Full regular-expressions are <i>not</i> supported
# due to limitations in the underlying LDAP protocol.
# This example selects any entry with a <tt>mail</tt> value containing
# the substring "anderson":
# f = Net::LDAP::Filter.eq( "mail", "*anderson*" )
#--
# Removed gt and lt. They ain't in the standard!
#
def Filter::eq attribute, value; Filter.new :eq, attribute, value; end
def Filter::ne attribute, value; Filter.new :ne, attribute, value; end
#def Filter::gt attribute, value; Filter.new :gt, attribute, value; end
#def Filter::lt attribute, value; Filter.new :lt, attribute, value; end
def Filter::ge attribute, value; Filter.new :ge, attribute, value; end
def Filter::le attribute, value; Filter.new :le, attribute, value; end
# #pres( attribute ) is a synonym for #eq( attribute, "*" )
#
def Filter::pres attribute; Filter.eq attribute, "*"; end
# operator & ("AND") is used to conjoin two or more filters.
# This expression will select only entries that have an <tt>objectclass</tt>
# attribute AND have a <tt>mail</tt> attribute that begins with "George":
# f = Net::LDAP::Filter.pres( "objectclass" ) & Net::LDAP::Filter.eq( "mail", "George*" )
#
def & filter; Filter.new :and, self, filter; end
# operator | ("OR") is used to disjoin two or more filters.
# This expression will select entries that have either an <tt>objectclass</tt>
# attribute OR a <tt>mail</tt> attribute that begins with "George":
# f = Net::LDAP::Filter.pres( "objectclass" ) | Net::LDAP::Filter.eq( "mail", "George*" )
#
def | filter; Filter.new :or, self, filter; end
#
# operator ~ ("NOT") is used to negate a filter.
# This expression will select only entries that <i>do not</i> have an <tt>objectclass</tt>
# attribute:
# f = ~ Net::LDAP::Filter.pres( "objectclass" )
#
#--
# This operator can't be !, evidently. Try it.
# Removed GT and LT. They're not in the RFC.
def ~@; Filter.new :not, self, nil; end
# Equality operator for filters, useful primarily for constructing unit tests.
def == filter
str = "[@op,@left,@right]"
self.instance_eval(str) == filter.instance_eval(str)
end
def to_s
case @op
when :ne
"(!(#{@left}=#{@right}))"
when :eq
"(#{@left}=#{@right})"
#when :gt
# "#{@left}>#{@right}"
#when :lt
# "#{@left}<#{@right}"
when :ge
"#{@left}>=#{@right}"
when :le
"#{@left}<=#{@right}"
when :and
"(&(#{@left})(#{@right}))"
when :or
"(|(#{@left})(#{@right}))"
when :not
"(!(#{@left}))"
else
raise "invalid or unsupported operator in LDAP Filter"
end
end
#--
# to_ber
# Filter ::=
# CHOICE {
# and [0] SET OF Filter,
# or [1] SET OF Filter,
# not [2] Filter,
# equalityMatch [3] AttributeValueAssertion,
# substrings [4] SubstringFilter,
# greaterOrEqual [5] AttributeValueAssertion,
# lessOrEqual [6] AttributeValueAssertion,
# present [7] AttributeType,
# approxMatch [8] AttributeValueAssertion
# }
#
# SubstringFilter
# SEQUENCE {
# type AttributeType,
# SEQUENCE OF CHOICE {
# initial [0] LDAPString,
# any [1] LDAPString,
# final [2] LDAPString
# }
# }
#
# Parsing substrings is a little tricky.
# We use the split method to break a string into substrings
# delimited by the * (star) character. But we also need
# to know whether there is a star at the head and tail
# of the string. A Ruby particularity comes into play here:
# if you split on * and the first character of the string is
# a star, then split will return an array whose first element
# is an _empty_ string. But if the _last_ character of the
# string is star, then split will return an array that does
# _not_ add an empty string at the end. So we have to deal
# with all that specifically.
#
def to_ber
case @op
when :eq
if @right == "*" # present
@left.to_s.to_ber_contextspecific 7
elsif @right =~ /[\*]/ #substring
ary = @right.split( /[\*]+/ )
final_star = @right =~ /[\*]$/
initial_star = ary.first == "" and ary.shift
seq = []
unless initial_star
seq << ary.shift.to_ber_contextspecific(0)
end
n_any_strings = ary.length - (final_star ? 0 : 1)
#p n_any_strings
n_any_strings.times {
seq << ary.shift.to_ber_contextspecific(1)
}
unless final_star
seq << ary.shift.to_ber_contextspecific(2)
end
[@left.to_s.to_ber, seq.to_ber].to_ber_contextspecific 4
else #equality
[@left.to_s.to_ber, unescape(@right).to_ber].to_ber_contextspecific 3
end
when :ge
[@left.to_s.to_ber, unescape(@right).to_ber].to_ber_contextspecific 5
when :le
[@left.to_s.to_ber, unescape(@right).to_ber].to_ber_contextspecific 6
when :and
ary = [@left.coalesce(:and), @right.coalesce(:and)].flatten
ary.map {|a| a.to_ber}.to_ber_contextspecific( 0 )
when :or
ary = [@left.coalesce(:or), @right.coalesce(:or)].flatten
ary.map {|a| a.to_ber}.to_ber_contextspecific( 1 )
when :not
[@left.to_ber].to_ber_contextspecific 2
else
# ERROR, we'll return objectclass=* to keep things from blowing up,
# but that ain't a good answer and we need to kick out an error of some kind.
raise "unimplemented search filter"
end
end
def unescape(right)
right.gsub(/\\([a-fA-F\d]{2,2})/) do
[$1.hex].pack("U")
end
end
# Converts an LDAP search filter in BER format to an Net::LDAP::Filter
# object. The incoming BER object most likely came to us by parsing an
# LDAP searchRequest PDU.
# Cf the comments under #to_ber, including the grammar snippet from the RFC.
#--
# We're hardcoding the BER constants from the RFC. Ought to break them out
# into constants.
#
def Filter::parse_ber ber
case ber.ber_identifier
when 0xa0 # context-specific constructed 0, "and"
ber.map {|b| Filter::parse_ber(b)}.inject {|memo,obj| memo & obj}
when 0xa1 # context-specific constructed 1, "or"
ber.map {|b| Filter::parse_ber(b)}.inject {|memo,obj| memo | obj}
when 0xa2 # context-specific constructed 2, "not"
~ Filter::parse_ber( ber.first )
when 0xa3 # context-specific constructed 3, "equalityMatch"
if ber.last == "*"
else
Filter.eq( ber.first, ber.last )
end
when 0xa4 # context-specific constructed 4, "substring"
str = ""
final = false
ber.last.each {|b|
case b.ber_identifier
when 0x80 # context-specific primitive 0, SubstringFilter "initial"
raise "unrecognized substring filter, bad initial" if str.length > 0
str += b
when 0x81 # context-specific primitive 0, SubstringFilter "any"
str += "*#{b}"
when 0x82 # context-specific primitive 0, SubstringFilter "final"
str += "*#{b}"
final = true
end
}
str += "*" unless final
Filter.eq( ber.first.to_s, str )
when 0xa5 # context-specific constructed 5, "greaterOrEqual"
Filter.ge( ber.first.to_s, ber.last.to_s )
when 0xa6 # context-specific constructed 5, "lessOrEqual"
Filter.le( ber.first.to_s, ber.last.to_s )
when 0x87 # context-specific primitive 7, "present"
# call to_s to get rid of the BER-identifiedness of the incoming string.
Filter.pres( ber.to_s )
else
raise "invalid BER tag-value (#{ber.ber_identifier}) in search filter"
end
end
# Perform filter operations against a user-supplied block. This is useful when implementing
# an LDAP directory server. The caller's block will be called with two arguments: first, a
# symbol denoting the "operation" of the filter; and second, an array consisting of arguments
# to the operation. The user-supplied block (which is MANDATORY) should perform some desired
# application-defined processing, and may return a locally-meaningful object that will appear
# as a parameter in the :and, :or and :not operations detailed below.
#
# A typical object to return from the user-supplied block is an array of
# Net::LDAP::Filter objects.
#
# These are the possible values that may be passed to the user-supplied block:
# :equalityMatch (the arguments will be an attribute name and a value to be matched);
# :substrings (two arguments: an attribute name and a value containing one or more * characters);
# :present (one argument: an attribute name);
# :greaterOrEqual (two arguments: an attribute name and a value to be compared against);
# :lessOrEqual (two arguments: an attribute name and a value to be compared against);
# :and (two or more arguments, each of which is an object returned from a recursive call
# to #execute, with the same block;
# :or (two or more arguments, each of which is an object returned from a recursive call
# to #execute, with the same block;
# :not (one argument, which is an object returned from a recursive call to #execute with the
# the same block.
#
def execute &block
case @op
when :eq
if @right == "*"
yield :present, @left
elsif @right.index '*'
yield :substrings, @left, @right
else
yield :equalityMatch, @left, @right
end
when :ge
yield :greaterOrEqual, @left, @right
when :le
yield :lessOrEqual, @left, @right
when :or, :and
yield @op, (@left.execute(&block)), (@right.execute(&block))
when :not
yield @op, (@left.execute(&block))
end || []
end
#--
# coalesce
# This is a private helper method for dealing with chains of ANDs and ORs
# that are longer than two. If BOTH of our branches are of the specified
# type of joining operator, then return both of them as an array (calling
# coalesce recursively). If they're not, then return an array consisting
# only of self.
#
def coalesce operator
if @op == operator
[@left.coalesce( operator ), @right.coalesce( operator )]
else
[self]
end
end
#--
# We get a Ruby object which comes from parsing an RFC-1777 "Filter"
# object. Convert it to a Net::LDAP::Filter.
# TODO, we're hardcoding the RFC-1777 BER-encodings of the various
# filter types. Could pull them out into a constant.
#
def Filter::parse_ldap_filter obj
case obj.ber_identifier
when 0x87 # present. context-specific primitive 7.
Filter.eq( obj.to_s, "*" )
when 0xa3 # equalityMatch. context-specific constructed 3.
Filter.eq( obj[0], obj[1] )
else
raise LdapError.new( "unknown ldap search-filter type: #{obj.ber_identifier}" )
end
end
#--
# We got a hash of attribute values.
# Do we match the attributes?
# Return T/F, and call match recursively as necessary.
def match entry
case @op
when :eq
if @right == "*"
l = entry[@left] and l.length > 0
else
l = entry[@left] and l = l.to_a and l.index(@right)
end
else
raise LdapError.new( "unknown filter type in match: #{@op}" )
end
end
# Converts an LDAP filter-string (in the prefix syntax specified in RFC-2254)
# to a Net::LDAP::Filter.
def self.construct ldap_filter_string
FilterParser.new(ldap_filter_string).filter
end
# Synonym for #construct.
# to a Net::LDAP::Filter.
def self.from_rfc2254 ldap_filter_string
construct ldap_filter_string
end
end # class Net::LDAP::Filter
class FilterParser #:nodoc:
attr_reader :filter
def initialize str
@filter = parse( StringScanner.new( str )) or raise Net::LDAP::LdapError.new( "invalid filter syntax" )
end
def parse scanner
parse_filter_branch(scanner) or parse_paren_expression(scanner)
end
def parse_paren_expression scanner
if scanner.scan(/\s*\(\s*/)
b = if scanner.scan(/\s*\&\s*/)
a = nil
branches = []
while br = parse_paren_expression(scanner)
branches << br
end
if branches.length >= 2
a = branches.shift
while branches.length > 0
a = a & branches.shift
end
a
end
elsif scanner.scan(/\s*\|\s*/)
# TODO: DRY!
a = nil
branches = []
while br = parse_paren_expression(scanner)
branches << br
end
if branches.length >= 2
a = branches.shift
while branches.length > 0
a = a | branches.shift
end
a
end
elsif scanner.scan(/\s*\!\s*/)
br = parse_paren_expression(scanner)
if br
~ br
end
else
parse_filter_branch( scanner )
end
if b and scanner.scan( /\s*\)\s*/ )
b
end
end
end
# Added a greatly-augmented filter contributed by Andre Nathan
# for detecting special characters in values. (15Aug06)
# Added blanks to the attribute filter (26Oct06)
def parse_filter_branch scanner
scanner.scan(/\s*/)
if token = scanner.scan( /[\w\-_]+/ )
scanner.scan(/\s*/)
if op = scanner.scan( /\=|\<\=|\<|\>\=|\>|\!\=/ )
scanner.scan(/\s*/)
#if value = scanner.scan( /[\w\*\.]+/ ) (ORG)
#if value = scanner.scan( /[\w\*\.\+\-@=#\$%&! ]+/ ) (ff suggested by Kouhei Sutou
if value = scanner.scan( /(?:[\w\*\.\+\-@=,#\$%&! ]|\\[a-fA-F\d]{2,2})+/ )
case op
when "="
Filter.eq( token, value )
when "!="
Filter.ne( token, value )
when "<"
Filter.lt( token, value )
when "<="
Filter.le( token, value )
when ">"
Filter.gt( token, value )
when ">="
Filter.ge( token, value )
end
end
end
end
end
end # class Net::LDAP::FilterParser
end # class Net::LDAP
end # module Net