Module: Datadog::AppSec::WAF::Converter

Defined in:
lib/datadog/appsec/waf/converter.rb

Overview

Module responsible for Ruby-to-C and C-to-Ruby conversions

Class Method Summary collapse

Class Method Details

.object_to_ruby(obj) ⇒ Object

standard:disable Metrics/MethodLength,Metrics/CyclomaticComplexity



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# File 'lib/datadog/appsec/waf/converter.rb', line 148

def object_to_ruby(obj)
  case obj[:type]
  when :ddwaf_obj_invalid, :ddwaf_obj_null
    nil
  when :ddwaf_obj_bool
    obj[:valueUnion][:boolean]
  when :ddwaf_obj_string
    # NOTE: FFI's `AbstractMemoryPointer#read_bytes` returns a binary string,
    #       which is not automatically encoded as UTF-8 and will raise an error
    #       if it contains non-ASCII characters and is used in a JSON#generate call.
    bytes = obj[:valueUnion][:stringValue].read_bytes(obj[:nbEntries])
    bytes.ascii_only? ? bytes : bytes.force_encoding(Encoding::UTF_8)
  when :ddwaf_obj_signed
    obj[:valueUnion][:intValue]
  when :ddwaf_obj_unsigned
    obj[:valueUnion][:uintValue]
  when :ddwaf_obj_float
    obj[:valueUnion][:f64]
  when :ddwaf_obj_array
    (0...obj[:nbEntries]).each.with_object([]) do |i, a|
      ptr = obj[:valueUnion][:array] + i * LibDDWAF::Object.size
      e = Converter.object_to_ruby(LibDDWAF::Object.new(ptr))
      a << e # steep:ignore
    end
  when :ddwaf_obj_map
    (0...obj[:nbEntries]).each.with_object({}) do |i, h|
      ptr = obj[:valueUnion][:array] + i * Datadog::AppSec::WAF::LibDDWAF::Object.size
      o = Datadog::AppSec::WAF::LibDDWAF::Object.new(ptr)
      l = o[:parameterNameLength]
      k = o[:parameterName].read_bytes(l)
      v = Converter.object_to_ruby(LibDDWAF::Object.new(ptr))
      h[k] = v # steep:ignore
    end
  end
end

.ruby_to_object(val, max_container_size: nil, max_container_depth: nil, max_string_length: nil, top_obj: nil, coerce: true) ⇒ Object

standard:disable Metrics/MethodLength,Metrics/CyclomaticComplexity



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# File 'lib/datadog/appsec/waf/converter.rb', line 11

def ruby_to_object(val, max_container_size: nil, max_container_depth: nil, max_string_length: nil, top_obj: nil, coerce: true)
  case val
  when Array
    obj = LibDDWAF::Object.new
    res = LibDDWAF.ddwaf_object_array(obj)
    raise ConversionError, "Could not convert into object: #{val}" if res.null?

    if max_container_depth == 0
      top_obj&.mark_truncated!
    else
      val.each.with_index do |e, i|
        if max_container_size && i >= max_container_size
          (top_obj || obj).mark_truncated!
          break val
        end

        member = Converter.ruby_to_object(
          e,
          max_container_size: max_container_size,
          max_container_depth: (max_container_depth - 1 if max_container_depth),
          max_string_length: max_string_length,
          top_obj: top_obj || obj,
          coerce: coerce
        )
        e_res = LibDDWAF.ddwaf_object_array_add(obj, member)
        raise ConversionError, "Could not add to array object: #{e.inspect}" unless e_res
      end
    end

    obj
  when Hash
    obj = LibDDWAF::Object.new
    res = LibDDWAF.ddwaf_object_map(obj)
    raise ConversionError, "Could not convert into object: #{val}" if res.null?

    if max_container_depth == 0
      top_obj&.mark_truncated!
    else
      val.each.with_index do |e, i|
        if max_container_size && i >= max_container_size
          (top_obj || obj).mark_truncated!
          break val
        end

        # for Steep, which doesn't handle |(k, v), i|
        k = e[0].to_s
        v = e[1]

        if max_string_length && k.length > max_string_length
          k = k[0, max_string_length]
          (top_obj || obj).mark_truncated!
        end
        member = Converter.ruby_to_object(
          v,
          max_container_size: max_container_size,
          max_container_depth: (max_container_depth - 1 if max_container_depth),
          max_string_length: max_string_length,
          top_obj: top_obj || obj,
          coerce: coerce
        )
        kv_res = LibDDWAF.ddwaf_object_map_addl(obj, k, k.bytesize, member)
        raise ConversionError, "Could not add to map object: #{e[0].inspect} => #{v.inspect}" unless kv_res
      end
    end

    obj
  when String
    obj = LibDDWAF::Object.new
    encoded_val = val.to_s.encode(Encoding::UTF_8, invalid: :replace, undef: :replace)
    if max_string_length && encoded_val.length > max_string_length
      encoded_val = encoded_val[0, max_string_length] #: String
      (top_obj || obj).mark_truncated!
    end
    res = LibDDWAF.ddwaf_object_stringl(obj, encoded_val, encoded_val.bytesize)
    raise ConversionError, "Could not convert into object: #{val.inspect}" if res.null?

    obj
  when Symbol
    obj = LibDDWAF::Object.new
    str = val.to_s
    if max_string_length && str.length > max_string_length
      str = str[0, max_string_length] #: String
      (top_obj || obj).mark_truncated!
    end
    res = LibDDWAF.ddwaf_object_stringl(obj, str, str.bytesize)
    raise ConversionError, "Could not convert into object: #{val.inspect}" if res.null?

    obj
  when Integer
    obj = LibDDWAF::Object.new
    res = if coerce
      LibDDWAF.ddwaf_object_string(obj, val.to_s)
    elsif val < 0
      LibDDWAF.ddwaf_object_signed(obj, val)
    else
      LibDDWAF.ddwaf_object_unsigned(obj, val)
    end
    raise ConversionError, "Could not convert into object: #{val.inspect}" if res.null?

    obj
  when Float
    obj = LibDDWAF::Object.new
    res = if coerce
      LibDDWAF.ddwaf_object_string(obj, val.to_s)
    else
      LibDDWAF.ddwaf_object_float(obj, val)
    end
    raise ConversionError, "Could not convert into object: #{val.inspect}" if res.null?

    obj
  when TrueClass, FalseClass
    obj = LibDDWAF::Object.new
    res = if coerce
      LibDDWAF.ddwaf_object_string(obj, val.to_s)
    else
      LibDDWAF.ddwaf_object_bool(obj, val)
    end
    raise ConversionError, "Could not convert into object: #{val.inspect}" if res.null?

    obj
  when NilClass
    obj = LibDDWAF::Object.new
    res = if coerce
      LibDDWAF.ddwaf_object_string(obj, "")
    else
      LibDDWAF.ddwaf_object_null(obj)
    end
    raise ConversionError, "Could not convert into object: #{val.inspect}" if res.null?

    obj
  else
    Converter.ruby_to_object("")
  end
end