Add Padder<>. A CRTP base for padding algorithms.

Expose block ciphers' key sizes for usage in compile-time context.

Chaos/Cipher/Block/Des/DesCrypt.hpp

@@ -233,6 +233,7 @@ public:
     class DesEncryptor : public Encryptor<DesEncryptor>
     {
     public:
+        using Key = DesCrypt::Key;
         static constexpr size_t BlockSize = DesCrypt::BlockSize;
         static constexpr size_t KeySize = DesCrypt::KeySize;
 
@@ -277,6 +278,7 @@ public:
     class DesDecryptor : public Decryptor<DesDecryptor>
     {
     public:
+        using Key = DesCrypt::Key;
         static constexpr size_t BlockSize = DesCrypt::BlockSize;
         static constexpr size_t KeySize = DesCrypt::KeySize;
 

Chaos/Padding/Padder.hpp

@@ -0,0 +1,34 @@
+#ifndef CHAOS_PADDING_PADDER_HPP
+#define CHAOS_PADDING_PADDER_HPP
+
+namespace Chaos::Padding
+{
+
+template<typename T>
+class Padder
+{
+public:
+    template<typename OutputIt>
+    void Pad(OutputIt begin, OutputIt end) const
+    {
+        Impl().Pad(begin, end);
+    }
+
+protected:
+    Padder() = default;
+
+private:
+    const T & Impl() const
+    {
+        return static_cast<const T &>(*this);
+    }
+
+    T & Impl()
+    {
+        return static_cast<T &>(*this);
+    }
+};
+
+} // namespace Chaos::Padding
+
+#endif // CHAOS_PADDING_PADDER_HPP

Chaos/Padding/PadderPkcs7.hpp

@@ -0,0 +1,38 @@
+#ifndef CHAOS_PADDING_PADDERPKCS7_HPP
+#define CHAOS_PADDING_PADDERPKCS7_HPP
+
+#include <cstdint>
+#include <iterator>
+#include <limits>
+
+#include "Padding/Padder.hpp"
+#include "Service/ChaosException.hpp"
+
+namespace Chaos::Padding
+{
+
+class PadderPkcs7 : public Padder<PadderPkcs7>
+{
+public:
+    template<typename OutputIt>
+    static void Pad(OutputIt begin, OutputIt end)
+    {
+        auto dist = std::distance(begin, end);
+
+        if (dist >= 0 && dist <= std::numeric_limits<uint8_t>::max())
+        {
+            for (OutputIt it = begin; it != end; ++it)
+            {
+                *it = static_cast<uint8_t>(dist);
+            }
+        }
+        else
+        {
+            throw Service::ChaosException("PadPkcs7::Pad(): invalid range");
+        }
+    }
+};
+
+} // namespace Chaos::Padding
+
+#endif // CHAOS_PADDING_PADDERPKCS7_HPP

ChaosTests/CMakeLists.txt

@@ -18,6 +18,7 @@ set(ChaosTests_SOURCE Hash/Md4HasherTests.cpp
                       Cipher/Arc4GenTests.cpp
                       Cipher/Arc4CryptTests.cpp
                       Cipher/DesCryptTests.cpp
+                      Padding/PadderPkcs7Tests.cpp
                       Service/SeArrayTests.cpp
                       Service/ChaosExceptionTests.cpp)
 

ChaosTests/Padding/PadderPkcs7Tests.cpp

@@ -0,0 +1,143 @@
+#include <gtest/gtest.h>
+#include <array>
+#include <cstdint>
+#include <vector>
+
+#include "Padding/PadderPkcs7.hpp"
+#include "Service/ChaosException.hpp"
+
+using namespace Chaos::Padding;
+
+TEST(PadPkcs7Tests, PadTest)
+{
+    {
+        std::array<uint8_t, 1> fact = {};
+        std::array<uint8_t, 1> expected = { 0x01 };
+
+        PadderPkcs7::Pad(fact.begin(), fact.end());
+        ASSERT_EQ(expected, fact);
+    }
+
+    {
+        std::array<uint8_t, 7> fact = {};
+        std::array<uint8_t, 7> expected =
+        {
+           0x07, 0x07, 0x07, 0x07, 0x07,
+           0x07, 0x07
+        };
+
+        PadderPkcs7::Pad(fact.begin(), fact.end());
+        ASSERT_EQ(expected, fact);
+    }
+
+    {
+        std::array<uint8_t, 10> fact = {};
+        std::array<uint8_t, 10> expected =
+        {
+           0x0a, 0x0a, 0x0a, 0x0a, 0x0a,
+           0x0a, 0x0a, 0x0a, 0x0a, 0x0a
+        };
+
+        PadderPkcs7::Pad(fact.begin(), fact.end());
+        ASSERT_EQ(expected, fact);
+    }
+
+    for (int i = 0; i < 256; ++i)
+    {
+        std::vector<uint8_t> fact(i, 0x00);
+
+        PadderPkcs7::Pad(fact.begin(), fact.end());
+        ASSERT_EQ(std::vector<uint8_t>(i, i), fact);
+    }
+}
+
+TEST(PadPkcs7Tests, PadInvalidRangeTest)
+{
+    {
+        std::array<uint8_t, 256> out = {};
+
+        ASSERT_THROW(PadderPkcs7::Pad(out.begin(), out.end()), Chaos::Service::ChaosException);
+    }
+
+    {
+        std::array<uint8_t, 500> out = {};
+
+        ASSERT_THROW(PadderPkcs7::Pad(out.begin(), out.end()), Chaos::Service::ChaosException);
+    }
+
+    {
+        std::array<uint8_t, 50> out = {};
+
+        ASSERT_THROW(PadderPkcs7::Pad(out.end(), out.begin()), Chaos::Service::ChaosException);
+    }
+}
+
+TEST(PadPkcs7Tests, PadOutIteratorUsageTest)
+{
+    {
+        std::array<uint8_t, 28> fact = {};
+        std::array<uint8_t, 28> expected =
+        {
+            0x00, 0x00, 0x00,
+            0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16,
+            0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16,
+            0x00, 0x00, 0x00
+        };
+
+        PadderPkcs7::Pad(fact.begin() + 3, fact.end() - 3);
+        ASSERT_EQ(expected, fact);
+    }
+
+    {
+        std::array<uint8_t, 39> fact = {};
+        std::array<uint8_t, 39> expected =
+        {
+            0x00, 0x00, 0x00,
+            0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
+            0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
+            0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
+            0x00, 0x00, 0x00
+        };
+
+        PadderPkcs7::Pad(fact.begin() + 3, fact.end() - 3);
+        ASSERT_EQ(expected, fact);
+    }
+
+    {
+        std::array<uint8_t, 10> fact =
+        {
+            0xbb, 0xbb, 0xbb, 0xbb, 0xbb,
+            0xbb, 0xbb, 0xbb, 0xbb, 0xbb
+        };
+        std::array<uint8_t, 10> expected =
+        {
+            0xbb, 0xbb, 0xbb, 0xbb, 0xbb,
+            0xbb, 0xbb, 0xbb, 0xbb, 0xbb
+        };
+
+        PadderPkcs7::Pad(fact.begin() + 5, fact.begin() + 5);
+        ASSERT_EQ(expected, fact);
+    }
+}
+
+template<typename Impl, typename OutputIt>
+void PadThroughBase(const Padder<Impl> & padder, OutputIt begin, OutputIt end)
+{
+    padder.Pad(begin, end);
+}
+
+TEST(PadPkcs7Tests, PadThroughBaseTest)
+{
+    {
+        std::array<uint8_t, 5> fact = {};
+        std::array<uint8_t, 5> expected =
+        {
+            0x05, 0x05, 0x05, 0x05, 0x05
+        };
+
+        const PadderPkcs7 padder;
+        PadThroughBase(padder, fact.begin(), fact.end());
+
+        ASSERT_EQ(expected, fact);
+    }
+}