Class: Binenc::Ruby::SBLFactory

Inherits:
Object
  • Object
show all
Includes:
SBLDSL
Defined in:
lib/binenc/factory/sbl_factory/sbl_factory.rb

Overview

simple binary layout factory

Instance Method Summary collapse

Methods included from SBLDSL

#bin, #date, #int, #oid, #seq, #str

Instance Method Details

#define(&block) ⇒ Object 



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# File 'lib/binenc/factory/sbl_factory/sbl_factory.rb', line 11

def define(&block)
  instance_eval(&block) 
  self
end

#encoded ⇒ Object 



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# File 'lib/binenc/factory/sbl_factory/sbl_factory.rb', line 16

def encoded
  res = []
  structure.each do |st|
    res << self.send("#{to_instance_method_name(st)}").encoded
  end

  ASN1Sequence.new(res).encoded
end

#from_bin(bin) ⇒ Object 



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# File 'lib/binenc/factory/sbl_factory/sbl_factory.rb', line 25

def from_bin(bin)
  
  seq = ASN1Object.decode(bin).value

  if seq.length > structure.length
    logger.warn "Given binary has more field (#{seq.length}) than the defined specification (#{structure.length}). Different version of structure?"
  elsif structure.length > seq.length
    logger.warn "Defined specification has more field (#{structure.length}) than given binary (#{seq.length}). Different version of structure?"
  end

  structure.each_index do |i|
    name = structure[i]
    
    if seq[i].is_a?(String)
      # begin block is to cater sequence but tagged as binary field
      # Therefore during 1st decode, it will become an array with actual value, 
      # no longer a ASN1 encoded field.
      # Different if the field is tagged as sequence, then this will not happened
      begin
        val = ASN1Object.decode(seq[i]).value
      rescue OpenSSL::ASN1::ASN1Error
        val = seq[i]
      end
    else
      val = seq[i]
    end

    case val
    when OpenSSL::BN
      val = val.to_i
    end
    create_instance_method(name, val)
  end

  self

end

#value_from_bin_struct(bin, *fieldNo) ⇒ Object 



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# File 'lib/binenc/factory/sbl_factory/sbl_factory.rb', line 63

def value_from_bin_struct(bin, *fieldNo)

  begin
    seq = ASN1Object.decode(bin).value

    ret = []
    fieldNo.each do |fn|
      raise BinencEngineException, "Given field no '#{fn}' to extract is larger than found fields (#{seq.length})" if fn > seq.length

      v = seq[fn]
      if v.is_a?(String)
        begin
          vv = ASN1Object.decode(v).value
        rescue OpenSSL::ASN1::ASN1Error
          vv = v
        end
      else
        vv = v
      end

      case vv
      when OpenSSL::BN
        ret << vv.to_i
      else
        ret << vv
      end
    end

    ret
  rescue OpenSSL::ASN1::ASN1Error => ex
    raise BinencDecodingError, ex
  end

end