Module: HEITT::Analyzer

Defined in:
lib/heitt.rb

Class Method Summary collapse

Class Method Details

.algorithm_scores(keyword_counts, database: HEITT::DATABASE) ⇒ Object 



137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
 
# File 'lib/heitt.rb', line 137

def self.algorithm_scores(keyword_counts, database: HEITT::DATABASE)
  scores = {}
  all_scores = []
  return scores if keyword_counts.nil?

  database.each do |entry|
    modes = get_modes(entry)
    next unless modes
    modes.each do |mode|
      contexts = mode[:context] || []
      next if contexts.empty?
      total = contexts.sum {|kw| keyword_counts[kw.downcase] || 0}
      scores[mode[:name]] = total if total > 0
    end
  end
  scores
end

.analyze(text, database: HEITT::DATABASE) ⇒ Object 



46
47
48
49
 
# File 'lib/heitt.rb', line 46

def self.analyze(text, database: HEITT::DATABASE)
  keyword_counts = keyword_counts(text.downcase, database: database)
  algorithm_scores(keyword_counts, database: database)
end

.assign_confidence(scores_hash, prefix_matched_mode = nil) ⇒ Object 



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
 
# File 'lib/heitt.rb', line 166

def self.assign_confidence(scores_hash,  prefix_matched_mode=nil)
  all_scores = scores_hash.values

  return {} if all_scores.empty?

  avg_score = all_scores.sum.to_f / all_scores.size
 
  scores_hash.transform_values do |score|
    if score == 0
      "regex-match"
    else
      mode_name = scores_hash.key(score)
      is_prefix_mode = (prefix_matched_mode == mode_name)
      deviation = (score - avg_score) / avg_score

      case deviation
      when 2.0..Float::INFINITY
        "high"
      when 0.5..2.0
        is_prefix_mode ? "high" : "medium-high"
      else
        is_prefix_mode ? "medium-high" : "medium-low"
      end
    end 
  end
end

.entropy(text) ⇒ Object

this code is a copy or inspiration of “github.com/chrisjchandler/entropy/blob/main/entropy.go”



105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
 
# File 'lib/heitt.rb', line 105

def self.entropy(text)
  frequency = Hash.new(0)
  text.each_char { |ch| frequency[ch] += 1 }

  #calculate the total number of characters
  total = text.length.to_f
  #caluclate entropy
  entropy = 0.0
  frequency.each_value do |count|
    probability = count.to_f / total
    entropy += probability * Math.log2(probability)
  end
  #negate the sum as entropy is positive
  -entropy
end

.extract_prefix(text, offset) ⇒ Object 



51
52
53
54
 
# File 'lib/heitt.rb', line 51

def self.extract_prefix(text, offset)
  line_start = text.rindex("\n", offset) || 0
  text[line_start...offset]
end

.get_modes(entry) ⇒ Object 



94
95
96
97
 
# File 'lib/heitt.rb', line 94

def self.get_modes(entry)
  entry[:modes] || entry[:algorithms] || entry[:hashes] || 
  entry[:candidates] || entry[:types] || entry[:hashtypes]
end

.high_entropy?(text, min_ent) ⇒ Boolean

Returns:

  • (Boolean) 


56
57
58
 
# File 'lib/heitt.rb', line 56

def self.high_entropy?(text, min_ent)
  entropy(text) >= min_ent
end

.keyword_counts(content_lower, database: HEITT::DATABASE) ⇒ Object 



121
122
123
124
125
126
127
128
129
130
131
132
133
134
 
# File 'lib/heitt.rb', line 121

def self.keyword_counts(content_lower, database: HEITT::DATABASE)
  keywords = database.flat_map do |entry|
    modes = get_modes(entry)
    next [] unless modes
    modes.flat_map {|mode| mode[:context] || []}
  end.uniq.map(&:downcase)

  counts = {}
  keywords.each do |kw|
    count = content_lower.scan(/\b#{Regexp.escape(kw)}\b/).size
    counts[kw] = count if count > 0
  end
  counts
end

.prefix_match?(mode, delim_prefix) ⇒ Boolean

Returns:

  • (Boolean) 


156
157
158
159
160
161
162
163
 
# File 'lib/heitt.rb', line 156

def self.prefix_match?(mode, delim_prefix)
  prefixes = mode[:prefixes] || []
  return false if prefixes.empty?

  delimiters =  "= : "
  raw_prefix = delim_prefix.strip.split(/[#{Regexp.escape(delimiters)}]/).last&.strip&.downcase
  prefixes.map(&:downcase).include?(raw_prefix)
end

.score_candidates(modes, delim_prefix, context_scores) ⇒ Object 



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
 
# File 'lib/heitt.rb', line 61

def self.score_candidates(modes, delim_prefix, context_scores)
  prefix_matched_mode = nil
  #context based scoring
  matches = modes.map do |mode|
    score_data = context_scores[mode[:name]]
    score = score_data || 0

    if prefix_match?(mode, delim_prefix)
      #boost score as confidence is high if prefix matched
      prefix_matched_mode = mode[:name]
      score += 20
    end
    #puts "MODENAME: #{mode[:name]}"
    {
      name: mode[:name],
      hashcat: mode[:hashcat],
      john: mode[:john],
      description: mode[:description],
      extended: mode[:extended],
      score: score
    }
  end 
  return [] if matches.empty?

  #calculate confidence
  scores_hash = matches.map {|m| [m[:name], m[:score]]}.to_h 
  
  confidences = assign_confidence(scores_hash, prefix_matched_mode)
  matches.map{|m| m.merge(confidence: confidences[m[:name]])}.sort_by {|m| -m[:score]}
end