#
# LDAP PDU support classes
#
#----------------------------------------------------------------------------
#
# 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 'ostruct'
module Net
class LdapPduError < StandardError; end
class LdapPdu
BindRequest = 0
BindResult = 1
UnbindRequest = 2
SearchRequest = 3
SearchReturnedData = 4
SearchResult = 5
ModifyResponse = 7
AddResponse = 9
DeleteResponse = 11
ModifyRDNResponse = 13
SearchResultReferral = 19
ExtendedRequest = 23
ExtendedResponse = 24
attr_reader :msg_id, :app_tag
attr_reader :search_dn, :search_attributes, :search_entry
attr_reader :search_referrals
attr_reader :search_parameters, :bind_parameters
# An LDAP PDU always looks like a BerSequence with
# at least two elements: an integer (message-id number), and
# an application-specific sequence.
# Some LDAPv3 packets also include an optional
# third element, which is a sequence of "controls"
# (See RFC 2251, section 4.1.12).
# The application-specific tag in the sequence tells
# us what kind of packet it is, and each kind has its
# own format, defined in RFC-1777.
# Observe that many clients (such as ldapsearch)
# do not necessarily enforce the expected application
# tags on received protocol packets. This implementation
# does interpret the RFC strictly in this regard, and
# it remains to be seen whether there are servers out
# there that will not work well with our approach.
#
# Added a controls-processor to SearchResult.
# Didn't add it everywhere because it just _feels_
# like it will need to be refactored.
#
def initialize ber_object
begin
@msg_id = ber_object[0].to_i
# Modified 25Nov06. We want to "un-decorate" the ber-identifier
# of the incoming packet. Originally we did this by subtracting 0x60,
# which ASSUMES the identifier is a constructed app-specific value.
# But at least one value (UnbindRequest) is app-specific primitive.
# So it makes more sense just to grab the bottom five bits.
#@app_tag = ber_object[1].ber_identifier - 0x60
@app_tag = ber_object[1].ber_identifier & 31
@ldap_controls = []
rescue
# any error becomes a data-format error
raise LdapPduError.new( "ldap-pdu format error" )
end
case @app_tag
when BindResult
parse_bind_response ber_object[1]
when SearchReturnedData
parse_search_return ber_object[1]
when SearchResultReferral
parse_search_referral ber_object[1]
when SearchResult
parse_ldap_result ber_object[1]
parse_controls(ber_object[2]) if ber_object[2]
when ModifyResponse
parse_ldap_result ber_object[1]
when AddResponse
parse_ldap_result ber_object[1]
when DeleteResponse
parse_ldap_result ber_object[1]
when ModifyRDNResponse
parse_ldap_result ber_object[1]
when SearchRequest
parse_ldap_search_request ber_object[1]
when BindRequest
parse_bind_request ber_object[1]
when UnbindRequest
parse_unbind_request ber_object[1]
when ExtendedResponse
parse_ldap_result ber_object[1]
else
raise LdapPduError.new( "unknown pdu-type: #{@app_tag}" )
end
end
# Returns a hash which (usually) defines the members :resultCode, :errorMessage, and :matchedDN.
# These values come directly from an LDAP response packet returned by the remote peer.
# See #result_code for a sugaring.
#
def result
@ldap_result || {}
end
# This returns an LDAP result code taken from the PDU,
# but it will be nil if there wasn't a result code.
# That can easily happen depending on the type of packet.
#
def result_code code = :resultCode
@ldap_result and @ldap_result[code]
end
# Return RFC-2251 Controls if any.
# Messy. Does this functionality belong somewhere else?
def result_controls
@ldap_controls
end
# Return serverSaslCreds, which are only present in BindResponse packets.
# Messy. Does this functionality belong somewhere else?
# We ought to refactor the accessors of this class before they get any kludgier.
def result_server_sasl_creds
@ldap_result && @ldap_result[:serverSaslCreds]
end
# parse_ldap_result
#
def parse_ldap_result sequence
sequence.length >= 3 or raise LdapPduError
@ldap_result = {:resultCode => sequence[0], :matchedDN => sequence[1], :errorMessage => sequence[2]}
end
private :parse_ldap_result
# A Bind Response may have an additional field, ID [7], serverSaslCreds, per RFC 2251 pgh 4.2.3.
#
def parse_bind_response sequence
sequence.length >= 3 or raise LdapPduError
@ldap_result = {:resultCode => sequence[0], :matchedDN => sequence[1], :errorMessage => sequence[2]}
@ldap_result[:serverSaslCreds] = sequence[3] if sequence.length >= 4
@ldap_result
end
private :parse_bind_response
# Definition from RFC 1777 (we're handling application-4 here)
#
# Search Response ::=
# CHOICE {
# entry [APPLICATION 4] SEQUENCE {
# objectName LDAPDN,
# attributes SEQUENCE OF SEQUENCE {
# AttributeType,
# SET OF AttributeValue
# }
# },
# resultCode [APPLICATION 5] LDAPResult
# }
#
# We concoct a search response that is a hash of the returned attribute values.
# NOW OBSERVE CAREFULLY: WE ARE DOWNCASING THE RETURNED ATTRIBUTE NAMES.
# This is to make them more predictable for user programs, but it
# may not be a good idea. Maybe this should be configurable.
# ALTERNATE IMPLEMENTATION: In addition to @search_dn and @search_attributes,
# we also return @search_entry, which is an LDAP::Entry object.
# If that works out well, then we'll remove the first two.
#
# Provisionally removed obsolete search_attributes and search_dn, 04May06.
#
def parse_search_return sequence
sequence.length >= 2 or raise LdapPduError
@search_entry = LDAP::Entry.new( sequence[0] )
sequence[1].each {|seq|
@search_entry[seq[0]] = seq[1]
}
end
# A search referral is a sequence of one or more LDAP URIs.
# Any number of search-referral replies can be returned by the server, interspersed
# with normal replies in any order.
# Until I can think of a better way to do this, we'll return the referrals as an array.
# It'll be up to higher-level handlers to expose something reasonable to the client.
def parse_search_referral uris
@search_referrals = uris
end
# Per RFC 2251, an LDAP "control" is a sequence of tuples, each consisting
# of an OID, a boolean criticality flag defaulting FALSE, and an OPTIONAL
# Octet String. If only two fields are given, the second one may be
# either criticality or data, since criticality has a default value.
# Someday we may want to come back here and add support for some of
# more-widely used controls. RFC-2696 is a good example.
#
def parse_controls sequence
@ldap_controls = sequence.map do |control|
o = OpenStruct.new
o.oid,o.criticality,o.value = control[0],control[1],control[2]
if o.criticality and o.criticality.is_a?(String)
o.value = o.criticality
o.criticality = false
end
o
end
end
private :parse_controls
# (provisional, must document)
def parse_ldap_search_request sequence
s = OpenStruct.new
s.base_object,
s.scope,
s.deref_aliases,
s.size_limit,
s.time_limit,
s.types_only,
s.filter,
s.attributes = sequence
@search_parameters = s
end
# (provisional, must document)
def parse_bind_request sequence
s = OpenStruct.new
s.version,
s.name,
s.authentication = sequence
@bind_parameters = s
end
# (provisional, must document)
# UnbindRequest has no content so this is a no-op.
def parse_unbind_request sequence
end
end
end # module Net