Added ASN1 visitors: base, mapping, and validation with specs. #LLM

LLM based addition that creates a visitor pattern (allowing a DER / ASN1 structure like much of Apple formats are) to be handled in a map/reduce and recursive way.

Author: rickmark

Gemfile.lock

@@ -11,6 +11,7 @@ PATH
       lzfse
       lzss
       plist
+      rasn1
       ruby-lzma
       ruby-macho
       rubyzip
@@ -223,6 +224,8 @@ GEM
     racc (1.8.1)
     rainbow (3.1.1)
     rake (13.4.2)
+    rasn1 (0.16.3)
+      strptime (~> 0.2.5)
     rb-fsevent (0.11.2)
     rb-inotify (0.11.1)
       ffi (~> 1.0)
@@ -332,6 +335,7 @@ GEM
       strscan (>= 1.0.0)
       terminal-table (>= 2, < 5)
       uri (>= 0.12.0)
+    strptime (0.2.5)
     strscan (3.1.8)
     terminal-table (3.0.2)
       unicode-display_width (>= 1.1.1, < 3)
@@ -531,6 +535,7 @@ CHECKSUMS
   racc (1.8.1) sha256=4a7f6929691dbec8b5209a0b373bc2614882b55fc5d2e447a21aaa691303d62f
   rainbow (3.1.1) sha256=039491aa3a89f42efa1d6dec2fc4e62ede96eb6acd95e52f1ad581182b79bc6a
   rake (13.4.2) sha256=cb825b2bd5f1f8e91ca37bddb4b9aaf345551b4731da62949be002fa89283701
+  rasn1 (0.16.3) sha256=56ed058761a1738921879239f2945d3163c2b1b2ef5d44b92c2ecde1a0eab3ff
   rb-fsevent (0.11.2) sha256=43900b972e7301d6570f64b850a5aa67833ee7d87b458ee92805d56b7318aefe
   rb-inotify (0.11.1) sha256=a0a700441239b0ff18eb65e3866236cd78613d6b9f78fea1f9ac47a85e47be6e
   rbi (0.4.3) sha256=cc090ae62c3246412b992954f54077d6046c9b04f1537a4d24bfae8714503eac
@@ -572,6 +577,7 @@ CHECKSUMS
   sorbet-static-and-runtime (0.6.13409) sha256=81841ba616bcfc473add238c7a9e2ee1693ee91706c6018557f02074357aa1e0
   spoom (1.8.7) sha256=81960502cdf23aa991f015988aa5dd43325e23ae4318b8e00d541299cbdb70f6
   steep (2.0.0) sha256=6eb0ecc09637bbb54f0a5f2cf63daea6d3208ccace64b4f1107d976333605c30
+  strptime (0.2.5) sha256=98ed77ff7717a47387ba473614f478e78b162d70a64072fd71d54f547e079af9
   strscan (3.1.8) sha256=aae2db611a225559f21ffbb71765c9a4e60fd262534a9ea84f4f11c7f32f679e
   terminal-table (3.0.2) sha256=f951b6af5f3e00203fb290a669e0a85c5dd5b051b3b023392ccfd67ba5abae91
   thor (1.5.0) sha256=e3a9e55fe857e44859ce104a84675ab6e8cd59c650a49106a05f55f136425e73

Rakefile

@@ -2,17 +2,10 @@
 
 Rake.add_rakelib 'tasks'
 
-
-
 desc 'Default task to run with no specification'
 task default: :spec
 
 desc 'Build environment by loading the gem'
 task :environment do
   require_relative 'lib/mootool'
 end
-
-
-
-
-

lib/mootool.rb

@@ -15,6 +15,7 @@
 require 'net/http'
 require 'fileutils'
 require 'apple_data'
+require 'rasn1'
 
 require 'zeitwerk'
 

lib/mootool/config/initializers/asn1.rb

@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+require 'openssl'
+
+module OpenSSL
+  module ASN1
+    class ASN1Data
+      # Returns true if this ASN1 object uses a PRIVATE tag class.
+      #
+      # @return [Boolean]
+      def private_tag?
+        tag_class == :PRIVATE
+      end
+
+      # Returns true if this ASN1 object uses a CONTEXT_SPECIFIC tag class.
+      #
+      # @return [Boolean]
+      def context_specific?
+        tag_class == :CONTEXT_SPECIFIC
+      end
+
+      # Returns true if this ASN1 object uses a UNIVERSAL tag class.
+      #
+      # @return [Boolean]
+      def universal?
+        tag_class == :UNIVERSAL
+      end
+
+      # Returns true if this ASN1 object is a Constructive (Sequence, Set, or tagged constructed).
+      #
+      # @return [Boolean]
+      def constructive?
+        is_a?(OpenSSL::ASN1::Constructive)
+      end
+
+      # Returns the tag value as a 4CC symbol when applicable (PRIVATE tags).
+      #
+      # @return [Symbol, Integer] The 4CC symbol or raw tag integer.
+      def tag_label
+        if private_tag? && tag.respond_to?(:to_4cc)
+          tag.to_4cc
+        else
+          tag
+        end
+      end
+    end
+  end
+end

lib/mootool/config/initializers/inflections.rb

@@ -17,4 +17,6 @@
   inflect.acronym 'DWARF'
   inflect.acronym 'ASN1'
   inflect.acronym 'RSA'
+  inflect.acronym 'RASN1'
+  inflect.acronym 'SSL'
 end

lib/mootool/helpers/img4.rb

@@ -19,7 +19,7 @@ module IMG4
 
       # Tags that require special decoding logic
       DECODE_TAGS = parse_4cc(
-        %w[prid time clid]
+        %w[prid time clid FSCl]
       )
 
       # Tags containing raw octet strings (often digests or IDs)
@@ -39,7 +39,7 @@ module IMG4
            smb0 auxi wmac smb1 smb2 upcl udid seid ESEC BNCH EPRO DSEC DPRO smb5 ronh AMNM trpk faic augs inst
            prid spih hrlp stng tbms vnum clas cnch fchp ndom pave styp type DGST EPRO ESEC CEPO SDOM SDOM BNCH
            EKEY CSEC CPRO BORD CHIP ECID uidm rpnh esdm apmv srvn eg0n prtp oppd sdkp snon snuf lpnh tatp tagt
-           tstp love kuid vuid rolp nish lobo nsih bmac faus fsca iuos rfcg esic epse]
+           tstp love kuid vuid rolp nish lobo nsih bmac faus fsca iuos rfcg esic epse FSC2 iCCl MSRk FSCl hop0]
       )
 
       # Tags identifying firmware entries
@@ -50,7 +50,7 @@ module IMG4
            pmpf rans rcio rdc2 rdcp rdtr recm rfts rkrn sptm rlg1 rlg2 rlgo bstc chg0 chg1 ciof stg1 csys dtre
            dcp2 dcpf isys dven ftap ftsp gfxf glyP ibdt ibec ibot ibss illb ispf ipdf rfta krnl logo msys mtfw
            mtpf pmcf pmpf rans rcio rdc2 rdcp rdtr recm rfts rkrn sptm rlg1 rlg2 rlgo rosi rsep tsep rspt rtmu
-           rtrx sepi siof lpol trxm trst tmuf bsys ADCL cfel hmmr pert phlt rbmt diag]
+           rtrx sepi siof lpol trxm trst tmuf bsys ADCL cfel hmmr pert phlt rbmt diag FSC2 iCCl MSRk]
       )
 
       # Mapping of IMG4 algorithm IDs to their Symbolic names

lib/mootool/models/decompressor.rb

@@ -132,15 +132,6 @@ def parse_based_on_hint(value, hint)
                       }
                     when :scrt
                       Models::Certificate.new(OpenSSL::X509::Certificate.new(value))
-                    when :FSC2
-                      @constructed.map do |item|
-                        case item
-                        when Integer
-                          item.to_4cc
-                        when Hash
-                          item.transform_keys(&:to_4cc)
-                        end
-                      end
                     else
                       { hint => construct(@asn1) }
                     end
@@ -179,7 +170,7 @@ def extract_to(path)
       def to_tree
         node = Helpers::TreeNode.new('Decompressor')
 
-        node.children << Helpers::TreeNode.new("Length: #{@value.size.ai}")
+        node.children << Helpers::TreeNode.new("Length: #{@value&.size.ai}")
         node.children << Helpers::TreeNode.new('Hash', [Helpers::TreeNode.new(to_hash(@hash))])
         node.children << Helpers::TreeNode.new("Encoding: #{@compression.ai}") if @compression
 

lib/mootool/models/descriptor_result.rb

@@ -18,6 +18,10 @@ def initialize(key, string_name)
         @string_name = string_name
       end
 
+      def inspect
+        @string_name.blank? ? @key.ai : "#{@key.ai}:#{string_name.ai}"
+      end
+
       # Compares this descriptor with another
       #
       # @param other [DescriptorResult, String, Symbol] The object to compare with.

lib/mootool/models/img4/img4_payload.rb

@@ -74,8 +74,10 @@ def parse_keybag(input)
         # @return [Hash] A validation status hash with :valid and :hash keys.
         def validate(manifest)
           firmware_tag = manifest.firmware_tag(@type)
+          return nil unless firmware_tag
 
           match = hashes.select do |hash|
+            puts(firmware_tag.ai) if firmware_tag.is_a? Array
             hash == firmware_tag.digest
           end
           @validated = {

lib/mootool/visitors.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module MooTool
+  # Visitor pattern implementations for traversing ASN1 structures.
+  #
+  # Provides a base visitor with depth and parent tracking, along with
+  # concrete visitors for mapping ASN1 to native Ruby types and for
+  # validating structures against RASN1 models.
+  #
+  # Supports both OpenSSL::ASN1 and RASN1::Types nodes via the
+  # {MooTool::Visitors::Adapters} adapter layer.
+  module Visitors
+  end
+end