Class: Rex::Post::Meterpreter::Tlv

Inherits:
Object
  • Object
show all
Defined in:
lib/rex/post/meterpreter/packet.rb

Overview

Base TLV (Type-Length-Value) class

Direct Known Subclasses

GroupTlv

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(type, value = nil, compress = false) ⇒ Tlv

Returns an instance of a TLV.


114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
 
# File 'lib/rex/post/meterpreter/packet.rb', line 114

def initialize(type, value = nil, compress=false)
  @type     = type
  @compress = compress

  if (value != nil)
    if (type & TLV_META_TYPE_STRING == TLV_META_TYPE_STRING)
      if (value.kind_of?(Fixnum))
        @value = value.to_s
      else
        @value = value.dup
      end
    else
      @value = value
    end
  end
end

Instance Attribute Details

#compress ⇒ Object

Returns the value of attribute compress


103
104
105
 
# File 'lib/rex/post/meterpreter/packet.rb', line 103

def compress
  @compress
end

#type ⇒ Object

Returns the value of attribute type


103
104
105
 
# File 'lib/rex/post/meterpreter/packet.rb', line 103

def type
  @type
end

#value ⇒ Object

Returns the value of attribute value


103
104
105
 
# File 'lib/rex/post/meterpreter/packet.rb', line 103

def value
  @value
end

Instance Method Details

#from_r(raw) ⇒ Object

Translates the raw format of the TLV into a sanitize version.


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
 
# File 'lib/rex/post/meterpreter/packet.rb', line 286

def from_r(raw)
  self.value  = nil

  length, self.type = raw.unpack("NN");

  # check if the tlv value has been compressed...
  if( self.type & TLV_META_TYPE_COMPRESSED == TLV_META_TYPE_COMPRESSED )    # set this TLV as using compression

    @compress = true    # remove the TLV_META_TYPE_COMPRESSED flag from the tlv type to restore the
    # tlv type to its origional, allowing for transparent data compression.

    self.type = self.type ^ TLV_META_TYPE_COMPRESSED    # decompress the compressed data (skipping the length and type DWORD's)

    raw_decompressed = Rex::Text.zlib_inflate( raw[8..length-1] )    # update the length to reflect the decompressed data length (+8 for the length and type DWORD's)

    length = raw_decompressed.length + 8    # update the raw buffer with the new length, decompressed data and updated type.

    raw = [length, self.type].pack("NN") + raw_decompressed
  end

  if (self.type & TLV_META_TYPE_STRING == TLV_META_TYPE_STRING)
    if (raw.length > 0)
      self.value = raw[8..length-2]
    else
      self.value = nil
    end
  elsif (self.type & TLV_META_TYPE_UINT == TLV_META_TYPE_UINT)
    self.value = raw.unpack("NNN")[2]
  elsif (self.type & TLV_META_TYPE_QWORD == TLV_META_TYPE_QWORD)
    self.value = raw.unpack("NNQ")[2]
    self.value = self.ntohq( self.value )
  elsif (self.type & TLV_META_TYPE_BOOL == TLV_META_TYPE_BOOL)
    self.value = raw.unpack("NNc")[2]

    if (self.value == 1)
      self.value = true
    else
      self.value = false
    end
  else
    self.value = raw[8..length-1]
  end

  return length;
end

#inspect ⇒ Object 


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
 
# File 'lib/rex/post/meterpreter/packet.rb', line 131

def inspect
  utype = type ^ TLV_META_TYPE_COMPRESSED
  group = false
  meta = case (utype & TLV_META_MASK)
    when TLV_META_TYPE_STRING; "STRING"
    when TLV_META_TYPE_UINT; "INT"
    when TLV_META_TYPE_RAW; "RAW"
    when TLV_META_TYPE_BOOL; "BOOL"
    when TLV_META_TYPE_QWORD; "QWORD"
    when TLV_META_TYPE_GROUP; group=true; "GROUP"
    when TLV_META_TYPE_COMPLEX; "COMPLEX"
    else; 'unknown-meta-type'
    end
  stype = case type
    when PACKET_TYPE_REQUEST; "Request"
    when PACKET_TYPE_RESPONSE; "Response"
    when TLV_TYPE_REQUEST_ID; "REQUEST-ID"
    when TLV_TYPE_METHOD; "METHOD"
    when TLV_TYPE_RESULT; "RESULT"
    when TLV_TYPE_EXCEPTION; "EXCEPTION"
    when TLV_TYPE_STRING; "STRING"
    when TLV_TYPE_UINT; "UINT"
    when TLV_TYPE_BOOL; "BOOL"

    when TLV_TYPE_LENGTH; "LENGTH"
    when TLV_TYPE_DATA; "DATA"
    when TLV_TYPE_FLAGS; "FLAGS"

    when TLV_TYPE_CHANNEL_ID; "CHANNEL-ID"
    when TLV_TYPE_CHANNEL_TYPE; "CHANNEL-TYPE"
    when TLV_TYPE_CHANNEL_DATA; "CHANNEL-DATA"
    when TLV_TYPE_CHANNEL_DATA_GROUP; "CHANNEL-DATA-GROUP"
    when TLV_TYPE_CHANNEL_CLASS; "CHANNEL-CLASS"
    when TLV_TYPE_CHANNEL_PARENTID; "CHANNEL-PARENTID"

    when TLV_TYPE_SEEK_WHENCE; "SEEK-WHENCE"
    when TLV_TYPE_SEEK_OFFSET; "SEEK-OFFSET"
    when TLV_TYPE_SEEK_POS; "SEEK-POS"

    when TLV_TYPE_EXCEPTION_CODE; "EXCEPTION-CODE"
    when TLV_TYPE_EXCEPTION_STRING; "EXCEPTION-STRING"

    when TLV_TYPE_LIBRARY_PATH; "LIBRARY-PATH"
    when TLV_TYPE_TARGET_PATH; "TARGET-PATH"
    when TLV_TYPE_MIGRATE_PID; "MIGRATE-PID"
    when TLV_TYPE_MIGRATE_LEN; "MIGRATE-LEN"
    when TLV_TYPE_MIGRATE_PAYLOAD; "MIGRATE-PAYLOAD"
    when TLV_TYPE_MIGRATE_ARCH; "MIGRATE-ARCH"

    #when Extensions::Stdapi::TLV_TYPE_NETWORK_INTERFACE; 'network-interface'
    #when Extensions::Stdapi::TLV_TYPE_IP; 'ip-address'
    #when Extensions::Stdapi::TLV_TYPE_NETMASK; 'netmask'
    #when Extensions::Stdapi::TLV_TYPE_MAC_ADDRESS; 'mac-address'
    #when Extensions::Stdapi::TLV_TYPE_MAC_NAME; 'interface-name'
    #when Extensions::Stdapi::TLV_TYPE_IP6_SCOPE; 'address-scope'
    #when Extensions::Stdapi::TLV_TYPE_INTERFACE_MTU; 'interface-mtu'
    #when Extensions::Stdapi::TLV_TYPE_INTERFACE_FLAGS; 'interface-flags'
    #when Extensions::Stdapi::TLV_TYPE_INTERFACE_INDEX; 'interface-index'

    else; "unknown-#{type}"
    end
  val = value.inspect
  if val.length > 50
    val = val[0,50] + ' ..."'
  end
  group ||= (self.class.to_s =~ /Packet/)
  if group
    tlvs_inspect = "tlvs=[\n"
    @tlvs.each { |t|
      tlvs_inspect << "  #{t.inspect}\n"
    }
    tlvs_inspect << "]"
  else
    tlvs_inspect = "meta=#{meta.ljust 10} value=#{val}"
  end
  "#<#{self.class} type=#{stype.ljust 15} #{tlvs_inspect}>"
end

#meta_type?(meta) ⇒ Boolean

Checks to see if a TLVs meta type is equivalent to the meta type passed.


218
219
220
 
# File 'lib/rex/post/meterpreter/packet.rb', line 218

def meta_type?(meta)
  return (self.type & meta == meta)
end

#to_r ⇒ Object

Converts the TLV to raw.


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
 
# File 'lib/rex/post/meterpreter/packet.rb', line 245

def to_r  # Forcibly convert to ASCII-8BIT encoding

  raw = value.to_s.unpack("C*").pack("C*")

  if (self.type & TLV_META_TYPE_STRING == TLV_META_TYPE_STRING)
    raw += "\x00"
  elsif (self.type & TLV_META_TYPE_UINT == TLV_META_TYPE_UINT)
    raw = [value].pack("N")
  elsif (self.type & TLV_META_TYPE_QWORD == TLV_META_TYPE_QWORD)
    raw = [ self.htonq( value.to_i ) ].pack("Q")
  elsif (self.type & TLV_META_TYPE_BOOL == TLV_META_TYPE_BOOL)
    if (value == true)
      raw = [1].pack("c")
    else
      raw = [0].pack("c")
    end
  end

  # check if the tlv is to be compressed...
  if( @compress )
    raw_uncompressed = raw    # compress the raw data

    raw_compressed = Rex::Text.zlib_deflate( raw_uncompressed )    # check we have actually made the raw data smaller...
    # (small blobs often compress slightly larger then the origional)
    # if the compressed data is not smaller, we dont use the compressed data

    if( raw_compressed.length < raw_uncompressed.length )      # if so, set the TLV's type to indicate compression is used

      self.type = self.type | TLV_META_TYPE_COMPRESSED      # update the raw data with the uncompressed data length + compressed data
      # (we include the uncompressed data length as the C side will need to know this for decompression)

      raw = [ raw_uncompressed.length ].pack("N") + raw_compressed
    end
  end

  return [raw.length + 8, self.type].pack("NN") + raw
end

#type?(type) ⇒ Boolean

Checks to see if the TLVs type is equivalent to the type passed.


225
226
227
 
# File 'lib/rex/post/meterpreter/packet.rb', line 225

def type?(type)
  return self.type == type
end

#value?(value) ⇒ Boolean

Checks to see if the TLVs value is equivalent to the value passed.


232
233
234
 
# File 'lib/rex/post/meterpreter/packet.rb', line 232

def value?(value)
  return self.value == value
end