1b8bce9051
1) We were incorrectly halting sequence-parses when the sequence contained a boolean FALSE value; 2) We were generating application strings with a tag class of 0x80 (context-specific) rather than 0x40.
285 lines
6.3 KiB
Ruby
285 lines
6.3 KiB
Ruby
# $Id$
|
|
#
|
|
# NET::BER
|
|
# Mixes ASN.1/BER convenience methods into several standard classes.
|
|
# Also provides BER parsing functionality.
|
|
#
|
|
#----------------------------------------------------------------------------
|
|
#
|
|
# 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
|
|
#
|
|
#---------------------------------------------------------------------------
|
|
#
|
|
#
|
|
|
|
|
|
|
|
|
|
module Net
|
|
|
|
module BER
|
|
|
|
class BerError < Exception; end
|
|
|
|
|
|
# This module is for mixing into IO and IO-like objects.
|
|
module BERParser
|
|
|
|
# The order of these follows the class-codes in BER.
|
|
# Maybe this should have been a hash.
|
|
TagClasses = [:universal, :application, :context_specific, :private]
|
|
|
|
BuiltinSyntax = {
|
|
:universal => {
|
|
:primitive => {
|
|
1 => :boolean,
|
|
2 => :integer,
|
|
4 => :string,
|
|
10 => :integer,
|
|
},
|
|
:constructed => {
|
|
16 => :array,
|
|
17 => :array
|
|
}
|
|
}
|
|
}
|
|
|
|
#
|
|
# read_ber
|
|
# TODO: clean this up so it works properly with partial
|
|
# packets coming from streams that don't block when
|
|
# we ask for more data (like StringIOs). At it is,
|
|
# this can throw TypeErrors and other nasties.
|
|
#
|
|
def read_ber syntax=nil
|
|
eof? and return nil
|
|
|
|
id = getc # don't trash this value, we'll use it later
|
|
tag = id & 31
|
|
tag < 31 or raise BerError.new( "unsupported tag encoding: #{id}" )
|
|
tagclass = TagClasses[ id >> 6 ]
|
|
encoding = (id & 0x20 != 0) ? :constructed : :primitive
|
|
|
|
n = getc
|
|
lengthlength,contentlength = if n <= 127
|
|
[1,n]
|
|
else
|
|
j = (0...(n & 127)).inject(0) {|mem,x| mem = (mem << 8) + getc}
|
|
[1 + (n & 127), j]
|
|
end
|
|
|
|
newobj = read contentlength
|
|
|
|
objtype = nil
|
|
[syntax, BuiltinSyntax].each {|syn|
|
|
if syn && (ot = syn[tagclass]) && (ot = ot[encoding]) && ot[tag]
|
|
objtype = ot[tag]
|
|
break
|
|
end
|
|
}
|
|
|
|
obj = case objtype
|
|
when :boolean
|
|
newobj != "\000"
|
|
when :string
|
|
(newobj || "").dup
|
|
when :integer
|
|
j = 0
|
|
newobj.each_byte {|b| j = (j << 8) + b}
|
|
j
|
|
when :array
|
|
seq = []
|
|
sio = StringIO.new( newobj || "" )
|
|
# Interpret the subobject, but note how the loop
|
|
# is built: nil ends the loop, but false (a valid
|
|
# BER value) does not!
|
|
while (e = sio.read_ber(syntax)) != nil
|
|
seq << e
|
|
end
|
|
seq
|
|
else
|
|
raise BerError.new( "unsupported object type: class=#{tagclass}, encoding=#{encoding}, tag=#{tag}" )
|
|
end
|
|
|
|
# Add the identifier bits into the object if it's a String or an Array.
|
|
# We can't add extra stuff to Fixnums and booleans, not that it makes much sense anyway.
|
|
obj and ([String,Array].include? obj.class) and obj.instance_eval "def ber_identifier; #{id}; end"
|
|
obj
|
|
|
|
end
|
|
|
|
end # module BERParser
|
|
end # module BER
|
|
|
|
end # module Net
|
|
|
|
|
|
class IO
|
|
include Net::BER::BERParser
|
|
end
|
|
|
|
require "stringio"
|
|
class StringIO
|
|
include Net::BER::BERParser
|
|
end
|
|
|
|
|
|
class String
|
|
def read_ber syntax=nil
|
|
StringIO.new(self).read_ber(syntax)
|
|
end
|
|
end
|
|
|
|
|
|
|
|
#----------------------------------------------
|
|
|
|
|
|
class FalseClass
|
|
#
|
|
# to_ber
|
|
#
|
|
def to_ber
|
|
"\001\001\000"
|
|
end
|
|
end
|
|
|
|
|
|
class TrueClass
|
|
#
|
|
# to_ber
|
|
#
|
|
def to_ber
|
|
"\001\001\001"
|
|
end
|
|
end
|
|
|
|
|
|
|
|
class Fixnum
|
|
#
|
|
# to_ber
|
|
#
|
|
def to_ber
|
|
i = [self].pack('w')
|
|
[2, i.length].pack("CC") + i
|
|
end
|
|
|
|
#
|
|
# to_ber_enumerated
|
|
#
|
|
def to_ber_enumerated
|
|
i = [self].pack('w')
|
|
[10, i.length].pack("CC") + i
|
|
end
|
|
|
|
#
|
|
# to_ber_length_encoding
|
|
#
|
|
def to_ber_length_encoding
|
|
if self <= 127
|
|
[self].pack('C')
|
|
else
|
|
i = [self].pack('N').sub(/^[\0]+/,"")
|
|
[0x80 + i.length].pack('C') + i
|
|
end
|
|
end
|
|
|
|
end # class Fixnum
|
|
|
|
|
|
class Bignum
|
|
|
|
def to_ber
|
|
i = [self].pack('w')
|
|
i.length > 126 and raise Net::BER::BerError.new( "range error in bignum" )
|
|
[2, i.length].pack("CC") + i
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
class String
|
|
#
|
|
# to_ber
|
|
# A universal octet-string is tag number 4,
|
|
# but others are possible depending on the context, so we
|
|
# let the caller give us one.
|
|
#
|
|
def to_ber code = 4
|
|
[code].pack('C') + length.to_ber_length_encoding + self
|
|
end
|
|
|
|
#
|
|
# to_ber_application_string
|
|
#
|
|
def to_ber_application_string code
|
|
to_ber( 0x40 + code )
|
|
end
|
|
|
|
#
|
|
# to_ber_contextspecific
|
|
#
|
|
def to_ber_contextspecific code
|
|
to_ber( 0x80 + code )
|
|
end
|
|
|
|
end # class String
|
|
|
|
|
|
|
|
class Array
|
|
#
|
|
# to_ber_appsequence
|
|
# An application-specific sequence usually gets assigned
|
|
# a tag that is meaningful to the particular protocol being used.
|
|
# This is different from the universal sequence, which usually
|
|
# gets a tag value of 16.
|
|
# Now here's an interesting thing: We're adding the X.690
|
|
# "application constructed" code at the top of the tag byte (0x60),
|
|
# but some clients, notably ldapsearch, send "context-specific
|
|
# constructed" (0xA0). The latter would appear to violate RFC-1777,
|
|
# but what do I know? We may need to change this.
|
|
#
|
|
|
|
def to_ber id = 0; to_ber_seq_internal( 0x30 + id ); end
|
|
def to_ber_set id = 0; to_ber_seq_internal( 0x31 + id ); end
|
|
def to_ber_sequence id = 0; to_ber_seq_internal( 0x30 + id ); end
|
|
def to_ber_appsequence id = 0; to_ber_seq_internal( 0x60 + id ); end
|
|
def to_ber_contextspecific id = 0; to_ber_seq_internal( 0xA0 + id ); end
|
|
|
|
private
|
|
def to_ber_seq_internal code
|
|
s = self.to_s
|
|
[code].pack('C') + s.length.to_ber_length_encoding + s
|
|
end
|
|
|
|
end # class Array
|
|
|
|
|
|
|
|
#----------------------------------------------
|
|
|
|
if __FILE__ == $0
|
|
puts "No default action"
|
|
end
|
|
|
|
|
|
|