CoCalc provides the best real-time collaborative environment for Jupyter Notebooks, LaTeX documents, and SageMath, scalable from individual users to large groups and classes!

1
require 'ruby_smb'
2

3
module Msf
4
module Util
5
module WindowsRegistry
6

7
  #
8
  # This module include helpers for the SECURITY hive
9
  #
10
  module Security
11

12
    include Msf::Util::WindowsCryptoHelpers
13

14
    # All of these structures were taken from Impacket secretsdump.py
15
    class CacheData < BinData::Record
16
      mandatory_parameter :user_name_length
17
      mandatory_parameter :domain_name_length
18
      mandatory_parameter :dns_domain_name_length
19
      mandatory_parameter :upn_length
20
      mandatory_parameter :effective_name_length
21
      mandatory_parameter :full_name_length
22
      mandatory_parameter :logon_script_length
23
      mandatory_parameter :profile_path_length
24
      mandatory_parameter :home_directory_length
25
      mandatory_parameter :home_directory_drive_length
26
      mandatory_parameter :group_count
27
      mandatory_parameter :logon_domain_name_length
28

29
      endian :little
30

31
      string   :enc_hash, length: 16
32
      string   :unknown, length: 56
33
      string16 :username, length: -> { user_name_length }, byte_align: 4
34
      string16 :domain_name, length: -> { domain_name_length }, byte_align: 4
35
      string16 :dns_domain_name, length: -> { dns_domain_name_length }, byte_align: 4
36
      string16 :upn, length: -> { upn_length }, byte_align: 4
37
      string16 :effective_name, length: -> { effective_name_length }, byte_align: 4
38
      string16 :full_name, length: -> { full_name_length }, byte_align: 4
39
      string16 :logon_script, length: -> { logon_script_length }, byte_align: 4
40
      string16 :profile_path, length: -> { profile_path_length }, byte_align: 4
41
      string16 :home_directory, length: -> { home_directory_length }, byte_align: 4
42
      string16 :home_directory_drive, length: -> { home_directory_drive_length }, byte_align: 4
43
      array    :groups, initial_length: -> { group_count }, byte_align: 4 do
44
        uint32 :relative_id
45
        uint32 :attributes
46
      end
47
      string16 :logon_domain_name, length: -> { logon_domain_name_length }, byte_align: 4
48
    end
49

50
    class CacheEntry < BinData::Record
51
      endian :little
52

53
      uint16    :user_name_length
54
      uint16    :domain_name_length
55
      uint16    :effective_name_length
56
      uint16    :full_name_length
57
      uint16    :logon_script_length
58
      uint16    :profile_path_length
59
      uint16    :home_directory_length
60
      uint16    :home_directory_drive_length
61
      uint32    :user_id
62
      uint32    :primary_group_id
63
      uint32    :group_count
64
      uint16    :logon_domain_name_length
65
      uint16    :logon_domain_id_length
66
      file_time :last_access
67
      uint32    :revision
68
      uint32    :sid_count
69
      uint16    :valid
70
      uint16    :iteration_count
71
      uint32    :sif_length
72
      uint32    :logon_package
73
      uint16    :dns_domain_name_length
74
      uint16    :upn_length
75
      string    :iv, length: 16
76
      string    :ch, length: 16
77
      array     :enc_data, type: :uint8, read_until: :eof
78
    end
79

80
    attr_accessor :lsa_vista_style
81

82
    def normalize_key(key)
83
      @root.blank? ? key : key.delete_prefix(@root)
84
    end
85

86
    # Retrieve the decrypted LSA secret key from a given BootKey. This also sets
87
    # the @lsa_vista_style attributes according to the registry keys found
88
    # under `HKLM\SECURITY\Policy`. If set to `true`, the system version is
89
    # Windows Vista and above, otherwise it is Windows XP or below.
90
    #
91
    # @param boot_key [String] The BootKey
92
    # @return [String] The decrypted LSA secret key
93
    def lsa_secret_key(boot_key)
94
      # vprint_status('Getting PolEKList...')
95
      _value_type, value_data = get_value(normalize_key('HKLM\\SECURITY\\Policy\\PolEKList'))
96
      if value_data
97
        # Vista or above system
98
        @lsa_vista_style = true
99

100
        lsa_key = decrypt_lsa_data(value_data, boot_key)
101
        lsa_key = lsa_key[68, 32] unless lsa_key.empty?
102
      else
103
        # vprint_status('Getting PolSecretEncryptionKey...')
104
        _value_type, value_data = get_value(normalize_key('HKLM\\SECURITY\\Policy\\PolSecretEncryptionKey'))
105
        # If that didn't work, then we're out of luck
106
        return nil if value_data.nil?
107

108
        # XP or below system
109
        @lsa_vista_style = false
110

111
        md5x = Digest::MD5.new
112
        md5x << boot_key
113
        1000.times do
114
          md5x << value_data[60, 16]
115
        end
116

117
        rc4 = OpenSSL::Cipher.new('rc4')
118
        rc4.decrypt
119
        rc4.key = md5x.digest
120
        lsa_key = rc4.update(value_data[12, 48])
121
        lsa_key << rc4.final
122
        lsa_key = lsa_key[0x10..0x1F]
123
      end
124

125
      lsa_key
126
    end
127

128
    # Returns the decrypted LSA secrets under HKLM\SECURITY\Policy\Secrets. For
129
    # this, the LSA secret key must be provided, which can be retrieved with
130
    # the #lsa_secret_key method.
131
    #
132
    # @param lsa_key [String] The LSA secret key
133
    # @return [Hash] A hash containing the LSA secrets.
134
    def lsa_secrets(lsa_key)
135
      keys = enum_key(normalize_key('HKLM\\SECURITY\\Policy\\Secrets'))
136
      return unless keys
137

138
      keys.delete('NL$Control')
139

140
      keys.each_with_object({}) do |key, lsa_secrets|
141
        _value_type, value_data = get_value(normalize_key("HKLM\\SECURITY\\Policy\\Secrets\\#{key}\\CurrVal"))
142
        encrypted_secret = value_data
143
        next unless encrypted_secret
144

145
        if @lsa_vista_style
146
          decrypted = decrypt_lsa_data(encrypted_secret, lsa_key)
147
          secret_size = decrypted[0, 4].unpack('L<').first
148
          secret = decrypted[16, secret_size]
149
        else
150
          encrypted_secret_size = encrypted_secret[0, 4].unpack('L<').first
151
          secret = decrypt_secret_data(encrypted_secret[(encrypted_secret.size - encrypted_secret_size)..-1], lsa_key)
152
        end
153
        lsa_secrets[key] = secret
154
      end
155
    end
156

157
    # Returns the decrypted NLKM secret key from
158
    # HKLM\SECURITY\Policy\Secrets\NL$KM\CurrVal. For this, the LSA secret key
159
    # must be provided, which can be retrieved with the #lsa_secret_key method.
160
    #
161
    # @param lsa_key [String] The LSA secret key
162
    # @return [String] The NLKM secret key
163
    def nlkm_secret_key(lsa_key)
164
      _value_type, value_data = get_value(normalize_key('HKLM\\SECURITY\\Policy\\Secrets\\NL$KM\\CurrVal'))
165
      return nil unless value_data
166

167
      if @lsa_vista_style
168
        nlkm_dec = decrypt_lsa_data(value_data, lsa_key)
169
      else
170
        value_data_size = value_data[0, 4].unpack('L<').first
171
        nlkm_dec = decrypt_secret_data(value_data[(value_data.size - value_data_size)..-1], lsa_key)
172
      end
173

174
      nlkm_dec
175
    end
176

177
    # This structure consolidates Cache data and information, as retrieved by the #cached_infos method
178
    CacheInfo = Struct.new(
179
      :name,
180
      :iteration_count,
181
      :real_iteration_count,
182
      :entry, # CacheEntry structure
183
      :data, # CacheData structure
184
      keyword_init: true
185
    )
186

187
    # Returns the decrypted Cache data and information from HKLM\Cache. For
188
    # this, the NLKM secret key must be provided, which can be retrieved with
189
    # the #nlkm_secret_key method.
190
    #
191
    # @param nlkm_key [String] The NLKM secret key
192
    # @return [Array] An array of CacheInfo structures containing the Cache information
193
    def cached_infos(nlkm_key)
194
      values = enum_values(normalize_key('HKLM\\SECURITY\\Cache'))
195
      unless values
196
        elog('[Msf::Util::WindowsRegistry::Sam::cached_hashes] No cashed entries')
197
        return
198
      end
199

200
      values.delete('NL$Control')
201

202
      iteration_count = nil
203
      if values.delete('NL$IterationCount')
204
        _value_type, value_data = reg_parser.get_value(normalize_key('HKLM\\SECURITY\\Cache'), 'NL$IterationCount')
205
        iteration_count = value_data.to_i
206
      end
207

208
      values.map do |value|
209
        _value_type, value_data = get_value(normalize_key('HKLM\\SECURITY\\Cache'), value)
210
        cache = CacheEntry.read(value_data)
211

212
        cache_info = CacheInfo.new(name: value, entry: cache)
213

214
        next cache_info unless cache.user_name_length > 0
215

216
        enc_data = cache.enc_data.map(&:chr).join
217
        if @lsa_vista_style
218
          dec_data = decrypt_aes(enc_data, nlkm_key[16...32], cache.iv)
219
        else
220
          dec_data = decrypt_hash(enc_data, nlkm_key, cache.iv)
221
        end
222

223
        params = cache.snapshot.to_h.select { |key, _v| key.to_s.end_with?('_length') }
224
        params[:group_count] = cache.group_count
225
        cache_data = CacheData.new(params).read(dec_data)
226
        cache_info.data = cache_data
227

228
        if @lsa_vista_style
229
          cache_info.iteration_count = iteration_count ? iteration_count : cache.iteration_count
230
          if (cache_info.iteration_count > 10240)
231
            cache_info.real_iteration_count = cache_info.iteration_count & 0xfffffc00
232
          else
233
            cache_info.real_iteration_count = cache_info.iteration_count * 1024
234
          end
235
        end
236

237
        cache_info
238
      end
239
    end
240

241
  end
242
end
243
end
244
end
245

246

247