Land #3794, NDR encoding specs

MSP-11370 #land

spec/lib/rex/encoder/ndr_spec.rb

@@ -0,0 +1,169 @@
+# -*- coding:binary -*-
+require 'spec_helper'
+
+require 'rex/encoder/ndr'
+
+describe Rex::Encoder::NDR do
+
+  describe ".align" do
+    subject { described_class.align(string) }
+
+    context "when empty string argument" do
+      let(:string) { "" }
+      it { is_expected.to eq("") }
+    end
+
+    context "when 32bit aligned length argument" do
+      let(:string) { "A" * 4 }
+      it { is_expected.to eq("") }
+    end
+
+    context "when 32bit unaligned length argument" do
+      let(:string) { "A" * 5 }
+      it "returns the padding, as null bytes, necessary to 32bit align the argument" do
+        is_expected.to eq("\x00\x00\x00")
+      end
+    end
+  end
+
+  describe ".long" do
+    subject { described_class.long(string) }
+    let(:string) { 0x41424344 }
+
+    it "encodes the arguments as 32-bit little-endian unsigned integer" do
+      is_expected.to eq("\x44\x43\x42\x41")
+    end
+
+    context "when argument bigger than 32-bit unsigned integer" do
+      let(:string) { 0x4142434445 }
+      it "truncates the argument" do
+        is_expected.to eq("\x45\x44\x43\x42")
+      end
+    end
+  end
+
+  describe ".short" do
+    subject { described_class.short(string) }
+    let(:string) { 0x4142 }
+
+    it "encodes the arguments as 16-bit little-endian unsigned integer" do
+      is_expected.to eq("\x42\x41")
+    end
+
+    context "when argument bigger than 16-bit unsigned integer" do
+      let(:string) { 0x41424344 }
+      it "truncates the argument" do
+        is_expected.to eq("\x44\x43")
+      end
+    end
+
+  end
+
+  describe ".byte" do
+    subject { described_class.byte(string) }
+    let(:string) { 0x41 }
+
+    it "encodes the arguments as 8-bit unsigned integer" do
+      is_expected.to eq("\x41")
+    end
+
+    context "when argument bigger than 8-bit unsigned integer" do
+      let(:string) { 0x4142 }
+      it "truncates the argument" do
+        is_expected.to eq("\x42")
+      end
+    end
+
+  end
+
+  describe ".UniConformantArray" do
+    subject { described_class.UniConformantArray(string) }
+    let(:string) { "ABCDE" }
+
+    it "returns the encoded string" do
+      is_expected.to be_kind_of(String)
+    end
+
+    it "starts encoding the string length as 32-bit little-endian unsigned integer" do
+      expect(subject.unpack("V").first).to eq(string.length)
+    end
+
+    it "adds the string argument" do
+      is_expected.to include(string)
+    end
+
+    it "ends with padding to make result length 32-bits aligned" do
+      is_expected.to end_with("\x00" * 3)
+    end
+  end
+
+  describe ".string" do
+    subject { described_class.string(string) }
+    let(:string) { "ABCD" }
+
+    it "returns the encoded string" do
+      is_expected.to be_kind_of(String)
+      expect(subject.length).to eq(20)
+    end
+
+    it "starts encoding string metadata" do
+      expect(subject.unpack("VVV")[0]).to eq(string.length)
+      expect(subject.unpack("VVV")[1]).to eq(0)
+      expect(subject.unpack("VVV")[2]).to eq(string.length)
+    end
+
+    it "adds the string argument null-byte terminated" do
+      is_expected.to include("ABCD\x00")
+    end
+
+    it "ends with padding to make result length 32-bits aligned" do
+      is_expected.to end_with("\x00" * 3)
+    end
+  end
+
+  describe ".wstring" do
+    subject { described_class.wstring(string) }
+
+    it_behaves_like "Rex::Encoder::NDR.wstring"
+  end
+
+  describe ".UnicodeConformantVaryingString" do
+    subject { described_class.UnicodeConformantVaryingString(string) }
+
+    it_behaves_like "Rex::Encoder::NDR.wstring"
+  end
+
+  describe ".uwstring" do
+    subject { described_class.uwstring(string) }
+
+    let(:string) { "ABCD" }
+
+    it "encodes the argument as null-terminated unicode string" do
+      is_expected.to include("A\x00B\x00C\x00D\x00\x00\x00")
+    end
+
+    it "starts encoding string metadata" do
+      expect(subject.unpack("VVVV")[1]).to eq(string.length + 1)
+      expect(subject.unpack("VVVV")[2]).to eq(0)
+      expect(subject.unpack("VVVV")[3]).to eq(string.length + 1)
+    end
+
+    it "ends with padding to make result length 32-bits aligned" do
+      is_expected.to end_with("\x00" * 2)
+      expect(subject.length).to eq(28)
+    end
+  end
+
+  describe ".wstring_prebuilt" do
+    subject { described_class.wstring_prebuilt(string) }
+
+    it_behaves_like "Rex::Encoder::NDR.wstring_prebuild"
+  end
+
+  describe ".UnicodeConformantVaryingStringPreBuilt" do
+    subject { described_class.UnicodeConformantVaryingStringPreBuilt(string) }
+
+    it_behaves_like "Rex::Encoder::NDR.wstring_prebuild"
+  end
+
+end

spec/support/shared/examples/rex/encoder/ndr/wstring.rb

@@ -0,0 +1,18 @@
+shared_examples_for "Rex::Encoder::NDR.wstring" do
+  let(:string) { "ABCD" }
+
+  it "encodes the argument as null-terminated unicode string" do
+    is_expected.to include("A\x00B\x00C\x00D\x00\x00\x00")
+  end
+
+  it "starts encoding string metadata" do
+    expect(subject.unpack("VVV")[0]).to eq(string.length + 1)
+    expect(subject.unpack("VVV")[1]).to eq(0)
+    expect(subject.unpack("VVV")[2]).to eq(string.length + 1)
+  end
+
+  it "ends with padding to make result length 32-bits aligned" do
+    is_expected.to end_with("\x00" * 2)
+    expect(subject.length).to eq(24)
+  end
+end

spec/support/shared/examples/rex/encoder/ndr/wstring_prebuild.rb

@@ -0,0 +1,39 @@
+shared_examples_for "Rex::Encoder::NDR.wstring_prebuild" do
+  context "when 2-byte aligned string length" do
+    let(:string) { "A\x00B\x00C\x00" }
+
+    it "encodes the argument as null-terminated unicode string" do
+      is_expected.to include("A\x00B\x00C\x00")
+    end
+
+    it "starts encoding string metadata" do
+      expect(subject.unpack("VVV")[0]).to eq(string.length / 2)
+      expect(subject.unpack("VVV")[1]).to eq(0)
+      expect(subject.unpack("VVV")[2]).to eq(string.length / 2)
+    end
+
+    it "ends with padding to make result length 32-bits aligned" do
+      is_expected.to end_with("\x00" * 2)
+      expect(subject.length).to eq(20)
+    end
+  end
+
+  context "when 2-byte unaligned string length" do
+    let(:string) { "A\x00B\x00C" }
+
+    it "encodes the argument as null-terminated unicode string" do
+      is_expected.to include("A\x00B\x00C\x00")
+    end
+
+    it "starts encoding string metadata" do
+      expect(subject.unpack("VVV")[0]).to eq((string.length + 1) / 2)
+      expect(subject.unpack("VVV")[1]).to eq(0)
+      expect(subject.unpack("VVV")[2]).to eq((string.length + 1) / 2)
+    end
+
+    it "ends with padding to make result length 32-bits aligned" do
+      is_expected.to end_with("\x00" * 2)
+      expect(subject.length).to eq(20)
+    end
+  end
+end