Module: Masscan::Parsers::Binary

Defined in:
lib/masscan/parsers/binary.rb

Overview

Note:

Ported from https://github.com/robertdavidgraham/masscan/blob/1.3.2/src/in-binary.c

Parses the masscan -oB output format.

Defined Under Namespace

Classes: CorruptedFile

Constant Summary collapse

BUF_MAX =

Maximum buffer length for a single record.

1024 * 1024
PSEUDO_RECORD_SIZE =

The "pseudo record" length

99
MASSCAN_VERSION_FAMILY =

Masscan binary format version compatibility.

"1.1"
MASSCAN_MAGIC =

The masscan binary format magic string.

"masscan/#{MASSCAN_VERSION_FAMILY}"
IP_PROTOCOLS =

Mapping of IP protocol numbers to keywords.

{
  Socket::IPPROTO_ICMP   => :icmp,
  Socket::IPPROTO_ICMPV6 => :icmp,

  Socket::IPPROTO_TCP => :tcp,
  Socket::IPPROTO_UDP => :udp,

  132 => :sctp # Socket::IPPROTO_SCTP might not always be defined
}
APP_PROTOCOLS =

List of application protocol keywords.

[
  nil,
  :heur,
  :ssh1,
  :ssh2,
  :http,
  :ftp,
  :dns_versionbind,
  :snmp,             # simple network management protocol, udp/161
  :nbtstat,          # netbios, udp/137
  :ssl3,
  :smb,              # SMB tcp/139 and tcp/445
  :smtp,
  :pop3,
  :imap4,
  :udp_zeroaccess,
  :x509_cert,
  :html_title,
  :html_full,
  :ntp,              # network time protocol, udp/123
  :vuln,
  :heartbleed,
  :ticketbleed,
  :vnc_rfb,
  :safe,
  :memcached,
  :scripting,
  :versioning,
  :coap,         # constrained app proto, udp/5683, RFC7252
  :telnet,
  :rdp,          # Microsoft Remote Desktop Protocol tcp/3389
  :http_server,  # HTTP "Server:" field
]

Class Method Summary collapse

Class Method Details

.decode_ipv4(ip) ⇒ IPAddr

Decodes an IPv4 address from an integer.

Parameters:

  • ip (Integer) —

    The IP in raw integer form.

Returns:

  • (IPAddr) —

    The decoded IPv4 address.



218
219
220
 
# File 'lib/masscan/parsers/binary.rb', line 218

def self.decode_ipv4(ip)
  IPAddr.new(ip,Socket::AF_INET)
end

.decode_ipv6(ipv6_hi, ipv6_lo) ⇒ IPAddr

Decodes an IPv6 address from two 64bit integers.

Parameters:

  • ipv6_hi (Integer) —

    The top-half of the 128bit IPv6 address.

  • ipv6_lo (Integer) —

    The top-half of the 128bit IPv6 address.

Returns:

  • (IPAddr) —

    The decoded IPv6 address.



234
235
236
 
# File 'lib/masscan/parsers/binary.rb', line 234

def self.decode_ipv6(ipv6_hi,ipv6_lo)
  IPAddr.new((ipv6_hi << 64) | ipv6_lo,Socket::AF_INET6)
end

.decode_reason(reason) ⇒ Array<:fin, :syn, :rst, :psh, :ack, :urg, :ece, :cwr>

Decodes a reason bitflag.

Parameters:

  • reason (Integer) —

    The reason bitflag.

Returns:

  • (Array<:fin, :syn, :rst, :psh, :ack, :urg, :ece, :cwr>) —

    The reason flags.



273
274
275
276
277
278
279
280
281
282
283
284
 
# File 'lib/masscan/parsers/binary.rb', line 273

def self.decode_reason(reason)
  flags = []
  flags << :fin if (reason & 0x01) != 0
  flags << :syn if (reason & 0x02) != 0
  flags << :rst if (reason & 0x04) != 0
  flags << :psh if (reason & 0x08) != 0
  flags << :ack if (reason & 0x10) != 0
  flags << :urg if (reason & 0x20) != 0
  flags << :ece if (reason & 0x40) != 0
  flags << :cwr if (reason & 0x80) != 0
  flags
end

.decode_timestamp(timestamp) ⇒ Time

Decodes a timestamp from an integer.

Parameters:

  • timestamp (Integer) —

    The raw UNIX timestamp integer.

Returns:

  • (Time) —

    The decoded time value.



205
206
207
 
# File 'lib/masscan/parsers/binary.rb', line 205

def self.decode_timestamp(timestamp)
  Time.at(timestamp)
end

.lookup_app_protocol(proto) ⇒ Symbol?

Looks up an application protocol number.

Parameters:

  • proto (Integer) —

    The application protocol number.

Returns:

  • (Symbol, nil) —

    The application protocol keyword.

See Also:



332
333
334
 
# File 'lib/masscan/parsers/binary.rb', line 332

def self.lookup_app_protocol(proto)
  APP_PROTOCOLS[proto]
end

.lookup_ip_protocol(proto) ⇒ :icmp, ...

Looks up an IP protocol number.

Parameters:

  • proto (Integer) —

    The IP protocol number.

Returns:

  • (:icmp, :tcp, :udp, :sctp, nil) —

    The IP protocol keyword.

See Also:



260
261
262
 
# File 'lib/masscan/parsers/binary.rb', line 260

def self.lookup_ip_protocol(proto)
  IP_PROTOCOLS[proto]
end

.open(path) {|file| ... } ⇒ File

Opens a binary file for parsing.

Parameters:

  • path (String) —

    The path to the file.

Yields:

  • (file) —

    If a block is given, it will be passed the opened file. Once the block returns, the file will be closed.

Yield Parameters:

  • The (File) —

    opened file.

Returns:

  • (File) —

    If no block was given, the opened file will be returned.



34
35
36
 
# File 'lib/masscan/parsers/binary.rb', line 34

def self.open(path,&block)
  File.open(path,'rb',&block)
end

.parse(io) {|record| ... } ⇒ Enumerator

Parses masscan binary data.

Parameters:

  • io (IO) —

    The IO object to read from.

Yields:

  • (record) —

    If a block is given, it will be passed each parsed record.

Yield Parameters:

Returns:

  • (Enumerator) —

    If no block is given, it will return an Enumerator.



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
 
# File 'lib/masscan/parsers/binary.rb', line 59

def self.parse(io)
  return enum_for(__method__,io) unless block_given?

  pseudo = read_pseudo_record(io)

  # look for the start time
  if (match = pseudo.match(/s:(\d+)/))
    start_time = decode_timestamp(match[1].to_i)
  end

  total_records = 0

  # read all records
  loop do
    # read the TYPE field
    unless (type = read_multibyte_uint(io))
      return
    end

    # read the LENGTH field
    unless (length = read_multibyte_uint(io))
      return
    end

    if length > BUF_MAX
      raise(CorruptedFile,"file corrupted")
    end

    # read the remainder of the record
    buffer = io.read(length)

    if buffer.length < length
      return
    end

    # parse the specific record type
    record = case type
             when 1 # STATUS: open
               parse_status(buffer,:open)
             when 2 # STATUS: closed
               parse_status(buffer,:closed)
             when 3 # BANNER
               parse_banner3(buffer)
             when 4
               io.getbyte
               parse_banner4(buffer)
             when 5
               parse_banner4(buffer)
             when 6 # STATUS: open
               parse_status2(buffer,:open)
             when 7 # STATUS: closed
               parse_status2(buffer,:closed)
             when 9
               parse_banner9(buffer)
             when 10 # Open6
               parse_status6(buffer,:open)
             when 11 # Closed6
               parse_status6(buffer,:closed)
             when 13 # Banner6
               parse_banner6(buffer)
             when 109 # 'm'.ord # FILEHEADER
               next
             else
               raise(CorruptedFile,"unknown type: #{type.inspect}")
             end

    if record
      start_time ||= record.timestamp

      yield record

      total_records += 1
    end
  end

  return total_records
end

.parse_banner3(buffer) ⇒ Buffer

Parses a banner record.

Parameters:

  • buffer (String) —

    The buffer to parse.

Returns:

  • (Buffer) —

    The parsed buffer record.



391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
 
# File 'lib/masscan/parsers/binary.rb', line 391

def self.parse_banner3(buffer)
  timestamp, ip, port, app_proto, payload = buffer.unpack('L>L>S>S>A*')

  timestamp = decode_timestamp(timestamp)
  ip        = decode_ipv4(ip)
  app_proto = lookup_app_protocol(app_proto)

  # defaults
  ip_proto = :tcp
  ttl = 0

  return Banner.new(
    protocol:     ip_proto,
    port:         port,
    ttl:          ttl,
    ip:           ip,
    timestamp:    timestamp,
    app_protocol: app_proto,
    payload:      payload
  )
end

.parse_banner4(buffer) ⇒ Buffer

Parses a banner record.

Parameters:

  • buffer (String) —

    The buffer to parse.

Returns:

  • (Buffer) —

    The parsed buffer record.



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
 
# File 'lib/masscan/parsers/binary.rb', line 422

def self.parse_banner4(buffer)
  if buffer.length < 13
    return
  end

  timestamp, ip, ip_proto, port, app_proto, payload = buffer.unpack('L>L>CS>S>A*')

  timestamp = decode_timestamp(timestamp)
  ip        = decode_ipv4(ip)
  ip_proto  = lookup_ip_protocol(ip_proto)
  app_proto = lookup_app_protocol(app_proto)

  # defaults
  ttl = 0

  return Banner.new(
    protocol:     ip_proto,
    port:         port,
    ttl:          ttl,
    ip:           ip,
    timestamp:    timestamp,
    app_protocol: app_proto,
    payload:      payload
  )
end

.parse_banner6(buffer) ⇒ Buffer

Parses a banner record.

Parameters:

  • buffer (String) —

    The buffer to parse.

Returns:

  • (Buffer) —

    The parsed buffer record.



570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
 
# File 'lib/masscan/parsers/binary.rb', line 570

def self.parse_banner6(buffer)
  timestamp, ip_proto, port, app_proto, ttl, ip_version, ipv6_hi, ipv6_lo, payload = buffer.unpack('L>CS>S>CCQ>Q>A*')
  timestamp  ||= 0xffffffff
  protocol   ||= 0xff
  port       ||= 0xffff
  app_proto  ||= 0xffff
  ttl        ||= 0xff
  ip_version ||= 0xff
  ipv6_hi    ||= 0xffffffff_ffffffff
  ipv6_lo    ||= 0xffffffff_ffffffff

  timestamp = decode_timestamp(timestamp)
  ip_proto  = lookup_ip_protocol(ip_proto)
  app_proto = lookup_app_protocol(app_proto)
  ipv6      = decode_ipv6(ipv6_hi,ipv6_lo)

  return Banner.new(
    protocol:     ip_proto,
    port:         port,
    ttl:          ttl,
    ip:           ipv6,
    timestamp:    timestamp,
    app_protocol: app_proto,
    payload:      payload
  )
end

.parse_banner9(buffer) ⇒ Buffer

Parses a banner record.

Parameters:

  • buffer (String) —

    The buffer to parse.

Returns:

  • (Buffer) —

    The parsed buffer record.



496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
 
# File 'lib/masscan/parsers/binary.rb', line 496

def self.parse_banner9(buffer)
  if buffer.length < 14
    return
  end

  timestamp, ip, ip_proto, port, app_proto, ttl, payload = buffer.unpack('L>L>CS>S>CA*')
  timestamp = decode_timestamp(timestamp)
  ip        = decode_ipv4(ip)
  ip_proto  = lookup_ip_protocol(ip_proto)
  app_proto = lookup_app_protocol(app_proto)

  return Banner.new(
    protocol:     ip_proto,
    port:         port,
    ttl:          ttl,
    ip:           ip,
    timestamp:    timestamp,
    app_protocol: app_proto,
    payload:      payload
  )
end

.parse_status(buffer, status) ⇒ Status

Parses a status record.

Parameters:

  • buffer (String) —

    The buffer to parse.

  • status (:open, :closed) —

    Indicates whether the port status is open or closed.

Returns:

  • (Status) —

    The parsed status record.



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
 
# File 'lib/masscan/parsers/binary.rb', line 348

def self.parse_status(buffer,status)
  if buffer.length < 12
    return
  end

  timestamp, ip, port, reason, ttl = buffer.unpack("L>L>S>CC")

  timestamp = decode_timestamp(timestamp)
  ip        = decode_ipv4(ip)
  reason    = decode_reason(reason)

  # if ARP, there will be a MAC address after the record
  mac = if ip == 0 && buffer.length >= 12+6
          buffer[12+6,6]
        end

  protocol = case port
             when 53, 123, 137, 161 then  :udp
             when 36422, 36412, 2905 then :sctp
             else                         :tcp
             end

  return Status.new(
    status:    status,
    protocol:  protocol,
    port:      port,
    reason:    reason,
    ttl:       ttl,
    ip:        ip,
    timestamp: timestamp,
    mac:       mac
  )
end

.parse_status2(buffer, status) ⇒ Status

Parses a status record.

Parameters:

  • buffer (String) —

    The buffer to parse.

  • status (:open, :closed) —

    Indicates whether the port status is open or closed.

Returns:

  • (Status) —

    The parsed status record.



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
 
# File 'lib/masscan/parsers/binary.rb', line 460

def self.parse_status2(buffer,status)
  if buffer.length < 13
    return
  end

  timestamp, ip, ip_proto, port, reason, ttl = buffer.unpack('L>L>CS>CC')
  timestamp = decode_timestamp(timestamp)
  ip        = decode_ipv4(ip)
  ip_proto  = lookup_ip_protocol(ip_proto)
  reason    = decode_reason(reason)

  mac = if ip == 0 && buffer.length >= 13+6
          buffer[13,6]
        end

  return Status.new(
    status:    status,
    protocol:  ip_proto,
    port:      port,
    reason:    reason,
    ttl:       ttl,
    ip:        ip,
    timestamp: timestamp,
    mac:       mac
  )
end

.parse_status6(buffer, status) ⇒ Status

Parses a status record.

Parameters:

  • buffer (String) —

    The buffer to parse.

  • status (:open, :closed) —

    Indicates whether the port status is open or closed.

Returns:

  • (Status) —

    The parsed status record.



530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
 
# File 'lib/masscan/parsers/binary.rb', line 530

def self.parse_status6(buffer,status)
  timestamp, ip_proto, port, reason, ttl, ip_version, ipv6_hi, ipv6_lo = buffer.unpack('L>CS>CCCQ>Q>')
  timestamp  ||= 0xffffffff
  ip_proto   ||= 0xff
  port       ||= 0xffff
  reason     ||= 0xff
  ttl        ||= 0xff
  ip_version ||= 0xff
  ipv6_hi    ||= 0xffffffff_ffffffff
  ipv6_lo    ||= 0xffffffff_ffffffff

  unless ip_version == 6
    raise(CorruptedFile,"expected ip_version to be 6: #{ip_version.inspect}")
  end

  timestamp = decode_timestamp(timestamp)
  ip_proto  = lookup_ip_protocol(ip_proto)
  reason    = decode_reason(reason)
  ipv6      = decode_ipv6(ipv6_hi,ipv6_lo)

  return Status.new(
    status:    status,
    protocol:  ip_proto,
    port:      port,
    reason:    reason,
    ttl:       ttl,
    ip:        ipv6,
    timestamp: timestamp
  )
end

.read_multibyte_uint(io) ⇒ Integer?

Reads a multi-byte unsigned integer.

Parameters:

  • io (IO) —

    The IO object to read from.

Returns:

  • (Integer, nil) —

    The unsigned integer, or nil if End-of-Stream was reached.



178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
 
# File 'lib/masscan/parsers/binary.rb', line 178

def self.read_multibyte_uint(io)
  unless (b = io.getbyte)
    return
  end

  type = b & 0x7f

  while (b & 0x80) != 0
    unless (b = io.getbyte)
      return
    end

    type = (type << 7) | (b & 0x7f)
  end

  return type
end

.read_pseudo_record(io) ⇒ String

Reads the "pseudo record" at the beginning of the file.

Parameters:

  • io (IO) —

    The IO object to read from.

Returns:

  • (String) —

    The read buffer.



155
156
157
158
159
160
161
162
163
164
165
166
167
 
# File 'lib/masscan/parsers/binary.rb', line 155

def self.read_pseudo_record(io)
  buffer = io.read(PSEUDO_RECORD_SIZE)

  if buffer.length < PSEUDO_RECORD_SIZE
    raise(CorruptedFile,"invalid masscan binary format")
  end

  unless buffer.start_with?(MASSCAN_MAGIC)
    raise(CorruptedFile,"unknown file format (expected #{MASSCAN_MAGIC})")
  end

  return buffer
end