Add YAML Mach-O parser fixtures

lib/macho/exceptions.rb

@@ -126,6 +126,14 @@ def initialize(num)
     end
   end
 
+  # Raised when a load command has an invalid size.
+  class LoadCommandSizeError < NotAMachOError
+    # @param size [Integer] the invalid size
+    def initialize(size)
+      super("Invalid Mach-O load command size: #{size}")
+    end
+  end
+
   # Raised when a load command can't be created manually.
   class LoadCommandNotCreatableError < MachOError
     # @param cmd_sym [Symbol] the uncreatable load command's symbol

lib/macho/load_commands.rb

@@ -332,6 +332,8 @@ def initialize(lc, lc_str)
           view = lc.view
 
           if view
+            raise LCStrMalformedError, lc if lc_str < lc.class.bytesize || lc_str >= lc.cmdsize
+
             lc_str_abs = view.offset + lc_str
             lc_end = view.offset + lc.cmdsize - 1
             raw_string = view.raw_data.slice(lc_str_abs..lc_end)

lib/macho/macho_file.rb

@@ -579,17 +579,27 @@ def check_filetype(filetype)
 
     # All load commands in the file.
     # @return [Array<LoadCommands::LoadCommand>] an array of load commands
+    # @raise [TruncatedFileError] if the declared load command data is incomplete
     # @raise [LoadCommandError] if an unknown load command is encountered
+    # @raise [LoadCommandSizeError] if a load command's size is invalid
     # @api private
     def populate_load_commands
       permissive = options.fetch(:permissive, false)
       offset = header.class.bytesize
+      load_commands_end = offset + sizeofcmds
+      raise TruncatedFileError if load_commands_end > @raw_data.bytesize
+
       load_commands = []
       @load_commands_by_type = Hash.new { |h, k| h[k] = [] }
 
       header.ncmds.times do
+        raise TruncatedFileError if offset + LoadCommands::LoadCommand.bytesize > load_commands_end
+
         fmt = Utils.specialize_format("L=", endianness)
         cmd = @raw_data.slice(offset, 4).unpack1(fmt)
+        cmdsize = @raw_data.slice(offset + 4, 4).unpack1(fmt)
+        raise LoadCommandSizeError, cmdsize if cmdsize % 4 != 0 || offset + cmdsize > load_commands_end
+
         cmd_sym = LoadCommands::LOAD_COMMANDS[cmd]
 
         raise LoadCommandError, cmd unless cmd_sym || permissive
@@ -602,6 +612,8 @@ def populate_load_commands
           LoadCommands::LoadCommand
         end
 
+        raise LoadCommandSizeError, cmdsize if cmdsize < klass.bytesize
+
         view = MachOView.new(self, @raw_data, endianness, offset)
         command = klass.new_from_bin(view)
 

test/bin/yaml2obj/Makefile

@@ -0,0 +1,8 @@
+YAMLS := $(wildcard *.yaml)
+MACHOS := $(YAMLS:.yaml=.macho)
+
+.PHONY: all
+all: $(MACHOS)
+
+%.macho: %.yaml
+	yaml2obj $< -o $@

test/bin/yaml2obj/big-endian.yaml

@@ -0,0 +1,11 @@
+--- !mach-o
+IsLittleEndian: false
+FileHeader:
+  magic: 0xFEEDFACE
+  cputype: 0x00000007
+  cpusubtype: 0x00000003
+  filetype: 0x00000001
+  ncmds: 0
+  sizeofcmds: 0
+  flags: 0x00000000
+...

test/bin/yaml2obj/build-version.yaml

@@ -0,0 +1,22 @@
+--- !mach-o
+IsLittleEndian: true
+FileHeader:
+  magic: 0xFEEDFACF
+  cputype: 0x01000007
+  cpusubtype: 0x00000003
+  filetype: 0x00000002
+  ncmds: 1
+  sizeofcmds: 32
+  flags: 0x00000000
+  reserved: 0x00000000
+LoadCommands:
+  - cmd: LC_BUILD_VERSION
+    cmdsize: 32
+    platform: 2
+    minos: 0x00080000
+    sdk: 0x00090000
+    ntools: 1
+    Tools:
+      - tool: 1
+        version: 0
+...

test/bin/yaml2obj/invalid-lcstr-offset.yaml

@@ -0,0 +1,18 @@
+--- !mach-o
+IsLittleEndian: true
+FileHeader:
+  magic: 0xFEEDFACF
+  cputype: 0x01000007
+  cpusubtype: 0x00000003
+  filetype: 0x00000002
+  ncmds: 1
+  sizeofcmds: 24
+  flags: 0x00000000
+  reserved: 0x00000000
+LoadCommands:
+  - cmd: LC_LOAD_DYLINKER
+    cmdsize: 24
+    name: 0
+    Content: test
+    ZeroPadBytes: 8
+...

test/bin/yaml2obj/load-cmdsize-too-large.yaml

@@ -0,0 +1,15 @@
+--- !mach-o
+IsLittleEndian: true
+FileHeader:
+  magic: 0xFEEDFACF
+  cputype: 0x01000007
+  cpusubtype: 0x00000003
+  filetype: 0x00000001
+  ncmds: 1
+  sizeofcmds: 8
+  flags: 0x00002000
+  reserved: 0x00000000
+LoadCommands:
+  - cmd: 0xDEADBEEF
+    cmdsize: 16
+...

test/bin/yaml2obj/load-cmdsize-too-small.yaml

@@ -0,0 +1,24 @@
+--- !mach-o
+IsLittleEndian: true
+FileHeader:
+  magic: 0xFEEDFACF
+  cputype: 0x01000007
+  cpusubtype: 0x00000003
+  filetype: 0x00000001
+  ncmds: 1
+  sizeofcmds: 56
+  flags: 0x00002000
+  reserved: 0x00000000
+LoadCommands:
+  - cmd: LC_SEGMENT_64
+    cmdsize: 56
+    segname: '__TEXT'
+    vmaddr: 0x1000
+    vmsize: 0x10
+    fileoff: 0
+    filesize: 0
+    maxprot: 7
+    initprot: 5
+    nsects: 0
+    flags: 0
+...

test/bin/yaml2obj/minimal.yaml

@@ -0,0 +1,12 @@
+--- !mach-o
+IsLittleEndian: true
+FileHeader:
+  magic: 0xFEEDFACF
+  cputype: 0x0100000C
+  cpusubtype: 0x00000000
+  filetype: 0x00000001
+  ncmds: 0
+  sizeofcmds: 0
+  flags: 0x00000000
+  reserved: 0x00000000
+...

test/bin/yaml2obj/rpath.yaml

@@ -0,0 +1,18 @@
+--- !mach-o
+IsLittleEndian: true
+FileHeader:
+  magic: 0xFEEDFACF
+  cputype: 0x01000007
+  cpusubtype: 0x00000003
+  filetype: 0x00000002
+  ncmds: 1
+  sizeofcmds: 24
+  flags: 0x00000000
+  reserved: 0x00000000
+LoadCommands:
+  - cmd: LC_RPATH
+    cmdsize: 24
+    path: 12
+    Content: /usr/lib
+    ZeroPadBytes: 3
+...

test/bin/yaml2obj/truncated-load-command-region.yaml

@@ -0,0 +1,12 @@
+--- !mach-o
+IsLittleEndian: true
+FileHeader:
+  magic: 0xFEEDFACF
+  cputype: 0x01000007
+  cpusubtype: 0x00000003
+  filetype: 0x00000001
+  ncmds: 0
+  sizeofcmds: 8
+  flags: 0x00002000
+  reserved: 0x00000000
+...

test/bin/yaml2obj/truncated-load-commands.yaml

@@ -0,0 +1,12 @@
+--- !mach-o
+IsLittleEndian: true
+FileHeader:
+  magic: 0xFEEDFACF
+  cputype: 0x01000007
+  cpusubtype: 0x00000003
+  filetype: 0x00000001
+  ncmds: 1
+  sizeofcmds: 0
+  flags: 0x00002000
+  reserved: 0x00000000
+...

test/bin/yaml2obj/unaligned-cmdsize.yaml

@@ -0,0 +1,17 @@
+--- !mach-o
+IsLittleEndian: true
+FileHeader:
+  magic: 0xFEEDFACF
+  cputype: 0x01000007
+  cpusubtype: 0x00000003
+  filetype: 0x00000002
+  ncmds: 1
+  sizeofcmds: 25
+  flags: 0x00000000
+  reserved: 0x00000000
+LoadCommands:
+  - cmd: LC_UUID
+    cmdsize: 25
+    uuid: 00112233-4455-6677-8899-AABBCCDDEEFF
+    ZeroPadBytes: 1
+...

test/test_macho.rb

@@ -27,6 +27,71 @@ def test_truncated_file
     end
   end
 
+  def test_load_command_with_size_smaller_than_its_structure
+    assert_raises MachO::LoadCommandSizeError do
+      MachO::MachOFile.new(fixture(:yaml2obj, "load-cmdsize-too-small.macho"))
+    end
+  end
+
+  def test_load_command_with_size_beyond_its_region
+    assert_raises MachO::LoadCommandSizeError do
+      MachO::MachOFile.new(fixture(:yaml2obj, "load-cmdsize-too-large.macho"))
+    end
+  end
+
+  def test_declared_load_commands_are_truncated
+    assert_raises MachO::TruncatedFileError do
+      MachO::MachOFile.new(fixture(:yaml2obj, "truncated-load-commands.macho"))
+    end
+  end
+
+  def test_declared_load_command_region_is_truncated
+    assert_raises MachO::TruncatedFileError do
+      MachO::MachOFile.new(fixture(:yaml2obj, "truncated-load-command-region.macho"))
+    end
+  end
+
+  def test_load_command_with_unaligned_size
+    assert_raises MachO::LoadCommandSizeError do
+      MachO::MachOFile.new(fixture(:yaml2obj, "unaligned-cmdsize.macho"))
+    end
+  end
+
+  def test_load_command_with_invalid_string_offset
+    command = MachO::MachOFile.new(fixture(:yaml2obj, "invalid-lcstr-offset.macho"))[:LC_LOAD_DYLINKER].first
+
+    assert_raises MachO::LCStrMalformedError do
+      command.name
+    end
+  end
+
+  def test_minimal_macho
+    file = MachO::MachOFile.new(fixture(:yaml2obj, "minimal.macho"))
+
+    assert file.object?
+    assert_equal :arm64, file.cputype
+  end
+
+  def test_big_endian_macho
+    file = MachO::MachOFile.new(fixture(:yaml2obj, "big-endian.macho"))
+
+    assert_equal :big, file.endianness
+    assert file.magic32?
+    assert_equal :i386, file.cputype
+  end
+
+  def test_build_version_command
+    command = MachO::MachOFile.new(fixture(:yaml2obj, "build-version.macho"))[:LC_BUILD_VERSION].first
+
+    assert_equal "8.0.0", command.minos_string
+    assert_equal "9.0.0", command.sdk_string
+    assert_equal 1, command.tool_entries.tools.size
+  end
+
+  def test_rpath_command
+    assert_equal ["/usr/lib"], MachO::MachOFile.new(fixture(:yaml2obj, "rpath.macho")).rpaths
+  end
+
   def test_load_commands
     filenames = SINGLE_ARCHES.map { |a| fixture(a, "hello.bin") }