Class: Rex::Proto::NTLM::Message

Inherits:
Base::FieldSet show all
Defined in:
lib/rex/proto/ntlm/message.rb

Defined Under Namespace

Classes: Type1, Type2, Type3

Constant Summary collapse

BASE = 
Rex::Proto::NTLM::Base
CONST = 
Rex::Proto::NTLM::Constants
CRYPT = 
Rex::Proto::NTLM::Crypt

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base::FieldSet

#[], #[]=, define, #disable, #enable, #initialize, int16LE, int32LE, int64LE, names, opts, #parse, prototypes, security_buffer, string, types

Constructor Details

This class inherits a constructor from Rex::Proto::NTLM::Base::FieldSet

Class Method Details

.decode64(str) ⇒ Object 



80
81
82
 
# File 'lib/rex/proto/ntlm/message.rb', line 80

def decode64(str)
	parse(Rex::Text::decode_base64(str))
end

.downgrade_type_message(message) ⇒ Object

Downgrading Type messages to LMv1/NTLMv1 and removing signing



492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
 
# File 'lib/rex/proto/ntlm/message.rb', line 492

def self.downgrade_type_message(message)
	decode = Rex::Text.decode_base64(message.strip)

	type = decode[8,1].unpack("C").first

	if (type > 0 and type < 4)
		reqflags = decode[12..15] if (type == 1 or type == 3)
		reqflags = decode[20..23] if (type == 2)
		reqflags = reqflags.unpack("V")

		# Remove NEGOTIATE_NTLMV2_KEY and NEGOTIATE_ALWAYS_SIGN, this lowers the negotiation
		# down to LMv1/NTLMv1.
		if (reqflags & CONST::NEGOTIATE_NTLM2_KEY) == CONST::NEGOTIATE_NTLM2_KEY
			reqflags = reqflags - CONST::NEGOTIATE_NTLM2_KEY
		end
		if (reqflags & CONST::NEGOTIATE_ALWAYS_SIGN) == CONST::NEGOTIATE_ALWAYS_SIGN
			reqflags = reqflags - CONST::NEGOTIATE_ALWAYS_SIGN
		end				
		
		# Return the flags back to the decode so we can base64 it again
		flags = reqflags.to_s(16)
		0.upto(8) do |idx|
			if (idx > flags.length)
				flags.insert(0, "0")
			end
		end

		idx = 0
		0.upto(3) do |cnt|
			if (type == 2)
				decode[23-cnt] = [flags[idx,1]].pack("C")
			else
				decode[15-cnt] = [flags[idx,1]].pack("C")
			end
			idx += 2
		end
		
	end
	return Rex::Text.encode_base64(decode).delete("\n") # base64 encode and remove the returns 
end

.parse(str) ⇒ Object 



64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
 
# File 'lib/rex/proto/ntlm/message.rb', line 64

def parse(str)
	m = Type0.new
	m.parse(str)
	case m.type
	when 1
		t = Type1.parse(str)
	when 2
		t = Type2.parse(str)
	when 3
		t = Type3.parse(str)
	else
		raise ArgumentError, "unknown type: #{m.type}"
	end
	t
end

.process_type1_message(message, nonce = "\x11\x22\x33\x44\x55\x66\x77\x88", win_domain = 'DOMAIN', win_name = 'SERVER', dns_name = 'server', dns_domain = 'example.com', downgrade = true) ⇒ Object

Process Type 1 NTLM Messages, return a Base64 Type 2 Message



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
 
# File 'lib/rex/proto/ntlm/message.rb', line 402

def self.process_type1_message(message, nonce = "\x11\x22\x33\x44\x55\x66\x77\x88", win_domain = 'DOMAIN', 
				win_name = 'SERVER', dns_name = 'server', dns_domain = 'example.com', downgrade = true)

	dns_name = Rex::Text.to_unicode(dns_name + "." + dns_domain)
	win_domain = Rex::Text.to_unicode(win_domain)
	dns_domain = Rex::Text.to_unicode(dns_domain)
	win_name = Rex::Text.to_unicode(win_name)
	decode = Rex::Text.decode_base64(message.strip)

	type = decode[8,1].unpack("C").first

	if (type == 1)
		# A type 1 message has been received, lets build a type 2 message response

		reqflags = decode[12,4]
		reqflags = reqflags.unpack("V").first

		if (reqflags & CONST::REQUEST_TARGET) == CONST::REQUEST_TARGET

			if (downgrade)
				# At this time NTLMv2 and signing requirements are not supported
				if (reqflags & CONST::NEGOTIATE_NTLM2_KEY) == CONST::NEGOTIATE_NTLM2_KEY
					reqflags = reqflags - CONST::NEGOTIATE_NTLM2_KEY
				end
				if (reqflags & CONST::NEGOTIATE_ALWAYS_SIGN) == CONST::NEGOTIATE_ALWAYS_SIGN
					reqflags = reqflags - CONST::NEGOTIATE_ALWAYS_SIGN
				end				
			end

			flags = reqflags + CONST::TARGET_TYPE_DOMAIN + CONST::TARGET_TYPE_SERVER				
			tid = true

			tidoffset = 48 + win_domain.length
			tidbuff = 
				[2].pack('v') +				# tid type, win domain
				[win_domain.length].pack('v') +
				win_domain +
				[1].pack('v') +				# tid type, server name
				[win_name.length].pack('v') +
				win_name +
				[4].pack('v')	+			 # tid type, domain name
				[dns_domain.length].pack('v') +
				dns_domain +
				[3].pack('v')	+			# tid type, dns_name
				[dns_name.length].pack('v') +
				dns_name
		else
			flags = CONST::NEGOTIATE_UNICODE + CONST::NEGOTIATE_NTLM
			tid = false
		end

		type2msg = "NTLMSSP\0" + # protocol, 8 bytes
			   "\x02\x00\x00\x00"		# type, 4 bytes

		if (tid)
			type2msg +=	# Target security info, 8 bytes. Filled if REQUEST_TARGET
			[win_domain.length].pack('v') +	 # Length, 2 bytes
			[win_domain.length].pack('v')	 # Allocated space, 2 bytes
		end

		type2msg +="\x30\x00\x00\x00" + #		Offset, 4 bytes
			 [flags].pack('V') +	# flags, 4 bytes
			 nonce +		# the nonce, 8 bytes
		 	 "\x00" * 8		# Context (all 0s), 8 bytes

		if (tid)
			type2msg +=		# Target information security buffer. Filled if REQUEST_TARGET
				[tidbuff.length].pack('v') +	# Length, 2 bytes
				[tidbuff.length].pack('v') +	# Allocated space, 2 bytes
				[tidoffset].pack('V') +		# Offset, 4 bytes (usually \x48 + length of win_domain)
				win_domain +			# Target name data (domain in unicode if REQUEST_UNICODE)
								# Target information data
				tidbuff +			#	Type, 2 bytes
								#	Length, 2 bytes
								#	Data (in unicode if REQUEST_UNICODE)
				"\x00\x00\x00\x00"		# Terminator, 4 bytes, all \x00
		end

		type2msg = Rex::Text.encode_base64(type2msg).delete("\n") # base64 encode and remove the returns
	else
		# This is not a Type2 message
		type2msg = ""
	end

	return type2msg
end

.process_type3_message(message) ⇒ Object

Process Type 3 NTLM Message (in Base64)

from www.innovation.ch/personal/ronald/ntlm.html

struct { byte protocol; // ‘N’, ‘T’, ‘L’, ‘M’, ‘S’, ‘S’, ‘P’, ‘0’ byte type; // 0x03 byte zero;

short lm_resp_len; // LanManager response length (always 0x18) short lm_resp_len; // LanManager response length (always 0x18) short lm_resp_off; // LanManager response offset byte zero;

short nt_resp_len; // NT response length (always 0x18) short nt_resp_len; // NT response length (always 0x18) short nt_resp_off; // NT response offset byte zero;

short dom_len; // domain string length short dom_len; // domain string length short dom_off; // domain string offset (always 0x40) byte zero;

short user_len; // username string length short user_len; // username string length short user_off; // username string offset byte zero;

short host_len; // host string length short host_len; // host string length short host_off; // host string offset byte zero;

short msg_len; // message length byte zero;

short flags; // 0x8201 byte zero;

byte dom; // domain string (unicode UTF-16LE) byte user; // username string (unicode UTF-16LE) byte host; // host string (unicode UTF-16LE) byte lm_resp; // LanManager response byte nt_resp; // NT response } type_3_message



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
 
# File 'lib/rex/proto/ntlm/message.rb', line 367

def self.process_type3_message(message)
	decode = Rex::Text.decode_base64(message.strip)
	type = decode[8,1].unpack("C").first
	if (type == 3)
		lm_len = decode[12,2].unpack("v").first
		lm_offset = decode[16,2].unpack("v").first
		lm = decode[lm_offset, lm_len].unpack("H*").first

		nt_len = decode[20,2].unpack("v").first
		nt_offset = decode[24,2].unpack("v").first
		nt = decode[nt_offset, nt_len].unpack("H*").first

		dom_len = decode[28,2].unpack("v").first
		dom_offset = decode[32,2].unpack("v").first
		domain = decode[dom_offset, dom_len]

		user_len = decode[36,2].unpack("v").first
		user_offset = decode[40,2].unpack("v").first
		user = decode[user_offset, user_len]

		host_len = decode[44,2].unpack("v").first
		host_offset = decode[48,2].unpack("v").first
		host = decode[host_offset, host_len]
	
		return domain, user, host, lm, nt
	else
		return "", "", "", "", ""
	end
end

Instance Method Details

#data_size ⇒ Object 



112
113
114
 
# File 'lib/rex/proto/ntlm/message.rb', line 112

def data_size
	security_buffers.inject(0){|sum, a| sum += a[1].data_size}
end

#decode64(str) ⇒ Object 



106
107
108
 
# File 'lib/rex/proto/ntlm/message.rb', line 106

def decode64(str)
	parse(Rex::Text::decode_base64(str))
end

#dump_flags ⇒ Object 



93
94
95
 
# File 'lib/rex/proto/ntlm/message.rb', line 93

def dump_flags
	CONST::FLAG_KEYS.each{ |k| print(k, "=", flag?(k), "\n") }
end

#encode64 ⇒ Object 



102
103
104
 
# File 'lib/rex/proto/ntlm/message.rb', line 102

def encode64
	Rex::Text::encode_base64(serialize)
end

#has_flag?(flag) ⇒ Boolean

self

Returns:

  • (Boolean) 


85
86
87
 
# File 'lib/rex/proto/ntlm/message.rb', line 85

def has_flag?(flag)
	(self[:flag].value & CONST::FLAGS[flag]) == CONST::FLAGS[flag]
end

#head_size ⇒ Object 



110
 
# File 'lib/rex/proto/ntlm/message.rb', line 110

alias head_size size

#serialize ⇒ Object 



97
98
99
100
 
# File 'lib/rex/proto/ntlm/message.rb', line 97

def serialize
	deflag
	super + security_buffers.map{|n, f| f.value}.join
end

#set_flag(flag) ⇒ Object 



89
90
91
 
# File 'lib/rex/proto/ntlm/message.rb', line 89

def set_flag(flag)
	self[:flag].value  |= CONST::FLAGS[flag]
end

#size ⇒ Object 



116
117
118
 
# File 'lib/rex/proto/ntlm/message.rb', line 116

def size
	head_size + data_size
end