Class: Ronin::ASM::Program

Inherits:
Object
  • Object
show all
Defined in:
lib/ronin/asm/program.rb

Overview

Represents a full Assembly program.

Direct Known Subclasses

Shellcode

Constant Summary collapse

SYNTAX =

Supported Assembly Syntaxs

{
  att:   Syntax::ATT,
  intel: Syntax::Intel
}
PARSERS =

The Assembly Parsers

{
  att:   :gas,
  intel: :nasm
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) { ... } ⇒ Program

Initializes a new Assembly Program.

Examples:

Program.new(arch: :amd64) do
  push  rax
  push  rbx

  mov   rsp,     rax
  mov   rax[8],  rbx
end

Parameters:

  • options (Hash) (defaults to: {}) —

    Additional options.

Options Hash (options):

  • :arch (String, Symbol) — default: :x86 —

    The Architecture to target.

  • :os (String, Symbol) —

    The Operating System to target.

  • :define (Hash{Symbol => Object}) —

    Constants to define in the program.

Yields:

  • [] The given block will be evaluated within the program.



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# File 'lib/ronin/asm/program.rb', line 105

def initialize(options={},&block)
  @arch = options.fetch(:arch,:x86).to_sym

  arch = Archs.const_get(@arch.to_s.upcase)

  @word_size = arch::WORD_SIZE
  @registers = arch::REGISTERS

  extend Archs.const_get(@arch.to_s.upcase)

  @syscalls = {}

  if options.has_key?(:os)
    @os       = options[:os].to_s
    @syscalls = OS::SYSCALLS[@os][@arch]

    extend OS.const_get(@os)
  end

  if options[:define]
    options[:define].each do |name,value|
      instance_variable_set("@#{name}",value)
    end
  end

  @allocated_registers = []
  @instructions = []

  instance_eval(&block) if block
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *arguments, &block) ⇒ Object (protected)

Allows adding unknown instructions to the program.

Parameters:

  • name (Symbol) —

    The name of the instruction.

  • arguments (Array) —

    Additional operands.



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# File 'lib/ronin/asm/program.rb', line 487

def method_missing(name,*arguments,&block)
  if (block && arguments.empty?)
    label(name,&block)
  elsif block.nil?
    if (arguments.empty? && register?(name))
      register(name)
    else
      instruction(name,*arguments)
    end
  else
    super(name,*arguments,&block)
  end
end

Instance Attribute Details

#allocated_registers ⇒ Object (readonly)

The registers used by the program



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# File 'lib/ronin/asm/program.rb', line 73

def allocated_registers
  @allocated_registers
end

#arch ⇒ Object (readonly)

The targeted architecture



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# File 'lib/ronin/asm/program.rb', line 52

def arch
  @arch
end

#instructions ⇒ Object (readonly)

The instructions of the program



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# File 'lib/ronin/asm/program.rb', line 76

def instructions
  @instructions
end

#os ⇒ Object (readonly)

The targeted Operating System



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# File 'lib/ronin/asm/program.rb', line 55

def os
  @os
end

#registers ⇒ Hash{Symbol => Register} (readonly)

The registers available to the program

Returns:

  • (Hash{Symbol => Register}) —

    The names and registers.



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# File 'lib/ronin/asm/program.rb', line 64

def registers
  @registers
end

#syscalls ⇒ Hash{Symbol => Integer} (readonly)

The syscalls available to the program

Returns:

  • (Hash{Symbol => Integer}) —

    The syscall names and numbers.



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# File 'lib/ronin/asm/program.rb', line 70

def syscalls
  @syscalls
end

#word_size ⇒ Object (readonly)

The default word size



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# File 'lib/ronin/asm/program.rb', line 58

def word_size
  @word_size
end

Instance Method Details

#assemble(output, options = {}) ⇒ String

Assembles the program.

Parameters:

  • output (String) —

    The path for the assembled program.

  • options (Hash) (defaults to: {}) —

    Additional options.

Options Hash (options):

  • :syntax (Symbol, String) — default: :intel —

    The syntax to compile the program to.

  • :format (Symbol) — default: :bin —

    The format of the assembled executable. May be one of:

    • :dbg - Trace of all info passed to object format module.
    • :bin - Flat format binary.
    • :dosexe - DOS .EXE format binary.
    • :elf - ELF.
    • :elf32 - ELF (32-bit).
    • :elf64 - ELF (64-bit).
    • :coff - COFF (DJGPP).
    • :macho - Mac OS X ABI Mach-O File Format.
    • :macho32 - Mac OS X ABI Mach-O File Format (32-bit).
    • :macho64 - Mac OS X ABI Mach-O File Format (64-bit).
    • :rdf - Relocatable Dynamic Object File Format (RDOFF) v2.0.
    • :win32 - Win32.
    • :win64 / :x64 - Win64.
    • :xdf - Extended Dynamic Object.

Returns:

  • (String) —

    The path to the assembled program.



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# File 'lib/ronin/asm/program.rb', line 453

def assemble(output,options={})
  syntax  = options.fetch(:syntax,:intel)
  format  = options.fetch(:format,:bin)
  parser  = PARSERS[syntax]

  source = Tempfile.new(['ronin-asm', '.s'])
  source.write(to_asm(syntax))
  source.close

  YASM::Program.assemble(
    file:          source.path,
    parser:        PARSERS[syntax],
    target:        @arch,
    output_format: format,
    output:        output
  )

  return output
end

#byte(op) ⇒ MemoryOperand, ImmediateOperand

Creates an operand of size 1 (byte).

Parameters:

Returns:



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# File 'lib/ronin/asm/program.rb', line 202

def byte(op)
  case op
  when MemoryOperand
    MemoryOperand.new(op.base,op.offset,op.index,op.scale,1)
  else
    ImmediateOperand.new(op,1)
  end
end

#critical(*regs) { ... } ⇒ Object

Defines a critical region, where the specified Registers should be saved and then reloaded.

Parameters:

  • regs (Array<Symbol>) —

    The registers to save and reload.

Yields:

  • [] The given block will be evaluated after the registers have been saved.



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# File 'lib/ronin/asm/program.rb', line 385

def critical(*regs,&block)
  regs.each { |name| register_save(name) }

  instance_eval(&block)

  regs.reverse_each { |name| register_load(name) }
end

#dword(op) ⇒ ImmediateOperand

Creates a operand of size 4 (bytes).

Parameters:

Returns:



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# File 'lib/ronin/asm/program.rb', line 238

def dword(op)
  case op
  when MemoryOperand
    MemoryOperand.new(op.base,op.offset,op.index,op.scale,4)
  else
    ImmediateOperand.new(op,4)
  end
end

#eval { ... } ⇒ Object

Evaluates code within the Program.

Yields:

  • [] The code to evaluate.



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# File 'lib/ronin/asm/program.rb', line 399

def eval(&block)
  instance_eval(&block)
end

#instruction(name, *operands) ⇒ Instruction

Adds a new instruction to the program.

Parameters:

  • name (String, Symbol)
  • operands (Array)

Returns:



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# File 'lib/ronin/asm/program.rb', line 186

def instruction(name,*operands)
  insn = Instruction.new(name.to_sym,operands)

  @instructions << insn
  return insn
end

#interrupt(number) ⇒ Object

This method is abstract.

Generic method for generating the instruction for causing an interrupt.

Parameters:

  • number (Integer) —

    The interrupt number to call.



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# File 'lib/ronin/asm/program.rb', line 294

def interrupt(number)
end

#label(name) { ... } ⇒ Symbol

Adds a label to the program.

Parameters:

  • name (Symbol, String) —

    The name of the label.

Yields:

  • [] The given block will be evaluated after the label has been added.

Returns:

  • (Symbol) —

    The label name.



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# File 'lib/ronin/asm/program.rb', line 278

def label(name,&block)
  name = name.to_sym

  @instructions << name
  instance_eval(&block)
  return name
end

#qword(op) ⇒ MemoryOperand, ImmediateOperand

Creates a operand of size 8 (bytes).

Parameters:

Returns:



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# File 'lib/ronin/asm/program.rb', line 256

def qword(op)
  case op
  when MemoryOperand
    MemoryOperand.new(op.base,op.offset,op.index,op.scale,8)
  else
    ImmediateOperand.new(op,8)
  end
end

#register(name) ⇒ Register

Accesses a register.

Parameters:

  • name (String, Symbol) —

    The name of the register.

Returns:

Raises:

  • (ArgumentError) —

    The register could not be found.



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# File 'lib/ronin/asm/program.rb', line 161

def register(name)
  name = name.to_sym

  unless register?(name)
    raise(ArgumentError,"unknown register: #{name}")
  end

  unless @allocated_registers.include?(name)
    # mark the register as being used, when it was first accessed
    @allocated_registers << name
  end

  return @registers[name]
end

#register?(name) ⇒ Boolean

Determines if a register exists.

Parameters:

  • name (Symbol) —

    The name of the register.

Returns:

  • (Boolean) —

    Specifies whether the register exists.



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# File 'lib/ronin/asm/program.rb', line 145

def register?(name)
  @registers.has_key?(name.to_sym)
end

#register_clear(name) ⇒ Object

This method is abstract.

Generic method for clearing a register.

Parameters:

  • name (Symbol) —

    The name of the reigster.



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# File 'lib/ronin/asm/program.rb', line 335

def register_clear(name)
end

#register_load(name) ⇒ Object

This method is abstract.

Generic method for loading a register.

Parameters:

  • name (Symbol) —

    The name of the reigster.



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# File 'lib/ronin/asm/program.rb', line 371

def register_load(name)
end

#register_save(name) ⇒ Object

This method is abstract.

Generic method for saving a register.

Parameters:

  • name (Symbol) —

    The name of the reigster.



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# File 'lib/ronin/asm/program.rb', line 360

def register_save(name)
end

#register_set(name, value) ⇒ Object

This method is abstract.

Generic method for setting a register.

Parameters:

  • name (Symbol) —

    The name of the reigster.

  • value (Register, Immediate, Integer) —

    The new value for the register.



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# File 'lib/ronin/asm/program.rb', line 349

def register_set(name,value)
end

#stack_pop(name) ⇒ Object

This method is abstract.

Generic method for popping off the stack.

Parameters:

  • name (Symbol) —

    The name of the reigster.



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# File 'lib/ronin/asm/program.rb', line 324

def stack_pop(name)
end

#stack_push(value) ⇒ Object

This method is abstract.

Generic method for pushing onto the stack.

Parameters:

  • value (Register, Integer) —

    The value to push.



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# File 'lib/ronin/asm/program.rb', line 313

def stack_push(value)
end

#syscall ⇒ Object

This method is abstract.

Generic method for generating the instruction for invoking a syscall.



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# File 'lib/ronin/asm/program.rb', line 302

def syscall
end

#to_asm(syntax = :intel) ⇒ Object

Converts the program to Assembly Source Code.

Parameters:

  • syntax (Symbol) (defaults to: :intel) —

    The syntax to compile the program to.



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# File 'lib/ronin/asm/program.rb', line 409

def to_asm(syntax=:intel)
  SYNTAX[syntax].emit_program(self)
end

#to_s ⇒ Object

See Also:



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# File 'lib/ronin/asm/program.rb', line 416

def to_s
  to_asm
end

#word(op) ⇒ MemoryOperand, ImmediateOperand

Creates a operand of size 2 (bytes).

Parameters:

Returns:



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# File 'lib/ronin/asm/program.rb', line 220

def word(op)
  case op
  when MemoryOperand
    MemoryOperand.new(op.base,op.offset,op.index,op.scale,2)
  else
    ImmediateOperand.new(op,2)
  end
end