refactoring

12 files changed, 121 insertions, 145 deletions

diff --git a/cxx/include/aesxx/api.hpp b/cxx/include/aesxx/api.hpp
index 5d21b63..2d0871f 100644
--- a/cxx/include/aesxx/api.hpp
+++ b/cxx/include/aesxx/api.hpp
@@ -66,20 +66,20 @@ namespace aes
         const typename Types<algorithm>::RoundKeys& encryption_keys,
         typename Types<algorithm>::RoundKeys& decryption_keys);
 
-    template <Algorithm algorithm, Mode mode, typename std::enable_if<ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<ModeRequiresInitVector<mode>::value>::type* = nullptr>
     inline void encrypt_block(
         const typename Types<algorithm>::Block& plaintext,
         const typename Types<algorithm>::RoundKeys& round_keys,
         typename Types<algorithm>::Block& iv,
         typename Types<algorithm>::Block& ciphertext);
 
-    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitVector<mode>::value>::type* = nullptr>
     inline void encrypt_block(
         const typename Types<algorithm>::Block& plaintext,
         const typename Types<algorithm>::RoundKeys& round_keys,
         typename Types<algorithm>::Block& ciphertext);
 
-    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitVector<mode>::value>::type* = nullptr>
     inline void encrypt_block(
         const typename Types<algorithm>::Block& plaintext,
         const typename Types<algorithm>::RoundKeys& round_keys,
@@ -89,20 +89,20 @@ namespace aes
         encrypt_block<algorithm, mode>(plaintext, round_keys, ciphertext);
     }
 
-    template <Algorithm algorithm, Mode mode, typename std::enable_if<ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<ModeRequiresInitVector<mode>::value>::type* = nullptr>
     inline void decrypt_block(
         const typename Types<algorithm>::Block& ciphertext,
         const typename Types<algorithm>::RoundKeys& round_keys,
         typename Types<algorithm>::Block& iv,
         typename Types<algorithm>::Block& plaintext);
 
-    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitVector<mode>::value>::type* = nullptr>
     inline void decrypt_block(
         const typename Types<algorithm>::Block& ciphertext,
         const typename Types<algorithm>::RoundKeys& round_keys,
         typename Types<algorithm>::Block& plaintext);
 
-    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitVector<mode>::value>::type* = nullptr>
     inline void decrypt_block(
         const typename Types<algorithm>::Block& ciphertext,
         const typename Types<algorithm>::RoundKeys& round_keys,
diff --git a/cxx/include/aesxx/mode.hpp b/cxx/include/aesxx/mode.hpp
index b6f3192..1c6c4cf 100644
--- a/cxx/include/aesxx/mode.hpp
+++ b/cxx/include/aesxx/mode.hpp
@@ -14,18 +14,18 @@ namespace aes
     typedef AES_Mode Mode;
 
     template <Mode mode>
-    struct ModeRequiresInitializationVector : public std::true_type
+    struct ModeRequiresInitVector : public std::true_type
     { };
 
     template <>
-    struct ModeRequiresInitializationVector<AES_ECB> : public std::false_type
+    struct ModeRequiresInitVector<AES_ECB> : public std::false_type
     { };
 
     template <Mode mode>
     struct ModeUsesEncryptionKeysOnly : public std::true_type
     { };
 
-    inline bool mode_requires_initialization_vector(Mode mode)
+    inline bool mode_requires_init_vector(Mode mode)
     {
         return mode != AES_ECB;
     }
diff --git a/utils/block_cmd_parser.hpp b/utils/block_cmd_parser.hpp
index ef92dce..70452e3 100644
--- a/utils/block_cmd_parser.hpp
+++ b/utils/block_cmd_parser.hpp
@@ -27,18 +27,14 @@ namespace
     class Settings
     {
     public:
-        aes::Algorithm get_algorithm() const { return algorithm; }
-        aes::Mode get_mode() const { return mode; }
+        aes::Algorithm algorithm = AES_AES128;
+        aes::Mode mode = AES_ECB;
 
-        bool use_boxes() const { return use_boxes_flag; }
-        bool verbose() const { return verbose_flag; }
+        bool use_boxes = false;
+        bool verbose = false;
 
     private:
-        aes::Algorithm algorithm;
-        aes::Mode mode;
-
-        bool use_boxes_flag = false;
-        bool verbose_flag = false;
+        Settings() = default;
 
         friend class CommandLineParser;
     };
@@ -46,21 +42,23 @@ namespace
     class CommandLineParser
     {
     public:
-        CommandLineParser(const std::string& argv0)
-            : prog_name(boost::filesystem::path(argv0).filename().string())
-            , options("Options")
+        explicit CommandLineParser(const std::string& argv0)
+            : prog_name{boost::filesystem::path{argv0}.filename().string()}
+            , options{"Options"}
         { }
 
-        void parse(Settings& settings, int argc, char** argv, std::vector<Input>& inputs)
+        Settings parse(int argc, char** argv, std::vector<Input>& inputs)
         {
+            Settings settings;
+
             namespace po = boost::program_options;
 
             options.add_options()
-                ("help,h", "show this message and exit")
-                ("use-boxes,b", po::bool_switch(&settings.use_boxes_flag)->default_value(false), "use the \"boxes\" interface")
-                ("mode,m", po::value<aes::Mode>(&settings.mode)->required(), "set mode of operation")
+                ("help,h",      "show this message and exit")
+                ("use-boxes,b", po::bool_switch(&settings.use_boxes)->default_value(false), "use the \"boxes\" interface")
+                ("mode,m",      po::value<aes::Mode>(&settings.mode)->required(), "set mode of operation")
                 ("algorithm,a", po::value<aes::Algorithm>(&settings.algorithm)->required(), "set algorithm")
-                ("verbose,v", po::bool_switch(&settings.verbose_flag)->default_value(false), "enable verbose output");
+                ("verbose,v",   po::bool_switch(&settings.verbose)->default_value(false), "enable verbose output");
 
             std::vector<std::string> args;
 
@@ -83,15 +81,16 @@ namespace
             if (vm.count("help"))
             {
                 help_flag = true;
-                return;
+                return settings;
             }
 
             po::notify(vm);
 
             parse_inputs(settings, inputs, std::deque<std::string>(
                 std::make_move_iterator(args.begin()),
-                std::make_move_iterator(args.end())
-            ));
+                std::make_move_iterator(args.end())));
+
+            return settings;
         }
 
         bool exit_with_usage() const { return help_flag; }
@@ -109,7 +108,7 @@ namespace
 
                 std::string iv_string;
 
-                if (aes::mode_requires_initialization_vector(settings.get_mode()))
+                if (aes::mode_requires_init_vector(settings.mode))
                 {
                     if (args.empty())
                     {
@@ -134,7 +133,7 @@ namespace
                     args.pop_front();
                 }
 
-                if (aes::mode_requires_initialization_vector(settings.get_mode()))
+                if (aes::mode_requires_init_vector(settings.mode))
                 {
                     inputs.emplace_back(
                         std::move(key_string),
diff --git a/utils/block_dumper.hpp b/utils/block_dumper.hpp
index 91ad2c6..df5b818 100644
--- a/utils/block_dumper.hpp
+++ b/utils/block_dumper.hpp
@@ -79,26 +79,26 @@ namespace
         dump_decryption_keys<algorithm>(wrapper.decryption_keys);
     }
 
-    template <aes::Algorithm algorithm, aes::Mode mode, typename std::enable_if<aes::ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <aes::Algorithm algorithm, aes::Mode mode, typename std::enable_if<aes::ModeRequiresInitVector<mode>::value>::type* = nullptr>
     void dump_next_iv(
         const aes::EncryptWrapper<algorithm, mode>& wrapper)
     {
         dump_block<algorithm>("Next initialization vector", wrapper.iv);
     }
 
-    template <aes::Algorithm algorithm, aes::Mode mode, typename std::enable_if<!aes::ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <aes::Algorithm algorithm, aes::Mode mode, typename std::enable_if<!aes::ModeRequiresInitVector<mode>::value>::type* = nullptr>
     void dump_next_iv(
         const aes::EncryptWrapper<algorithm, mode>&)
     { }
 
-    template <aes::Algorithm algorithm, aes::Mode mode, typename std::enable_if<aes::ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <aes::Algorithm algorithm, aes::Mode mode, typename std::enable_if<aes::ModeRequiresInitVector<mode>::value>::type* = nullptr>
     void dump_next_iv(
         const aes::DecryptWrapper<algorithm, mode>& wrapper)
     {
         dump_block<algorithm>("Next initialization vector", wrapper.iv);
     }
 
-    template <aes::Algorithm algorithm, aes::Mode mode, typename std::enable_if<!aes::ModeRequiresInitializationVector<mode>::value>::type* = nullptr>
+    template <aes::Algorithm algorithm, aes::Mode mode, typename std::enable_if<!aes::ModeRequiresInitVector<mode>::value>::type* = nullptr>
     void dump_next_iv(
         const aes::DecryptWrapper<algorithm, mode>&)
     { }
diff --git a/utils/data_parsers.hpp b/utils/data_parsers.hpp
index 89270fe..33c766a 100644
--- a/utils/data_parsers.hpp
+++ b/utils/data_parsers.hpp
@@ -21,11 +21,11 @@ static std::istream& operator>>(std::istream& is, aes::Mode& dest)
 
     static std::map<std::string, aes::Mode> lookup_table =
     {
-        { "ecb", AES_ECB },
-        { "cbc", AES_CBC },
-        { "cfb", AES_CFB },
-        { "ofb", AES_OFB },
-        { "ctr", AES_CTR },
+        {"ecb", AES_ECB},
+        {"cbc", AES_CBC},
+        {"cfb", AES_CFB},
+        {"ofb", AES_OFB},
+        {"ctr", AES_CTR},
     };
 
     const auto it = lookup_table.find(boost::algorithm::to_lower_copy(src));
@@ -44,9 +44,9 @@ static std::istream& operator>>(std::istream& is, aes::Algorithm& dest)
 
     static std::map<std::string, aes::Algorithm> lookup_table =
     {
-        { "aes128", AES_AES128 },
-        { "aes192", AES_AES192 },
-        { "aes256", AES_AES256 },
+        {"aes128", AES_AES128},
+        {"aes192", AES_AES192},
+        {"aes256", AES_AES256},
     };
 
     const auto it = lookup_table.find(boost::algorithm::to_lower_copy(src));
diff --git a/utils/decrypt_block.cpp b/utils/decrypt_block.cpp
index 9e53d2b..4744d49 100644
--- a/utils/decrypt_block.cpp
+++ b/utils/decrypt_block.cpp
@@ -25,7 +25,7 @@ namespace
     {
         typename aes::Types<algorithm>::Block iv;
 
-        if (aes::ModeRequiresInitializationVector<mode>())
+        if (aes::ModeRequiresInitVector<mode>())
         {
             aes::from_string<algorithm>(iv, input.get_iv_string());
             if (verbose)
@@ -144,7 +144,7 @@ namespace
         aes::Box::Key key;
         aes::Box::parse_key(key, algorithm, input.get_key_string());
 
-        if (aes::mode_requires_initialization_vector(mode))
+        if (aes::mode_requires_init_vector(mode))
         {
             aes::Box::Block iv;
             aes::Box::parse_block(iv, algorithm, input.get_iv_string());
@@ -164,12 +164,11 @@ int main(int argc, char** argv)
 {
     try
     {
-        CommandLineParser cmd_parser(argv[0]);
+        CommandLineParser cmd_parser{argv[0]};
         try
         {
-            Settings settings;
             std::vector<Input> inputs;
-            cmd_parser.parse(settings, argc, argv, inputs);
+            const auto settings = cmd_parser.parse(argc, argv, inputs);
 
             if (cmd_parser.exit_with_usage())
             {
@@ -179,20 +178,20 @@ int main(int argc, char** argv)
 
             for (const auto& input : inputs)
             {
-                if (settings.use_boxes())
+                if (settings.use_boxes)
                 {
                     decrypt_using_boxes(
-                        settings.get_algorithm(),
-                        settings.get_mode(),
+                        settings.algorithm,
+                        settings.mode,
                         input);
                 }
                 else
                 {
                     decrypt_using_cxx_api(
-                        settings.get_algorithm(),
-                        settings.get_mode(),
+                        settings.algorithm,
+                        settings.mode,
                         input,
-                        settings.verbose());
+                        settings.verbose);
                 }
             }
         }
diff --git a/utils/decrypt_bmp.cpp b/utils/decrypt_bmp.cpp
index 17a64dd..a68b1d3 100644
--- a/utils/decrypt_bmp.cpp
+++ b/utils/decrypt_bmp.cpp
@@ -33,27 +33,24 @@ namespace
 
     void decrypt_bmp(const Settings& settings)
     {
-        const auto algorithm = settings.get_algorithm();
-        const auto mode = settings.get_mode();
-
-        const auto& ciphertext_path = settings.get_input_path();
-        const auto& plaintext_path = settings.get_output_path();
+        const auto& algorithm = settings.algorithm;
+        const auto& mode = settings.mode;
 
         aes::Box::Key key;
-        aes::Box::parse_key(key, algorithm, settings.get_key_string());
+        aes::Box::parse_key(key, algorithm, settings.key);
 
-        if (aes::mode_requires_initialization_vector(mode))
+        if (aes::mode_requires_init_vector(mode))
         {
             aes::Box::Block iv;
-            aes::Box::parse_block(iv, algorithm, settings.get_iv_string());
-            aes::Box box{algorithm, key, mode, iv};
+            aes::Box::parse_block(iv, algorithm, settings.iv);
 
-            decrypt_bmp(box, ciphertext_path, plaintext_path);
+            aes::Box box{algorithm, key, mode, iv};
+            decrypt_bmp(box, settings.input_path, settings.output_path);
         }
         else
         {
             aes::Box box{algorithm, key};
-            decrypt_bmp(box, ciphertext_path, plaintext_path);
+            decrypt_bmp(box, settings.input_path, settings.output_path);
         }
     }
 }
@@ -65,8 +62,7 @@ int main(int argc, char** argv)
         CommandLineParser cmd_parser(argv[0]);
         try
         {
-            Settings settings;
-            cmd_parser.parse(settings, argc, argv);
+            const auto settings = cmd_parser.parse(argc, argv);
 
             if (cmd_parser.exit_with_usage())
             {
diff --git a/utils/decrypt_file.cpp b/utils/decrypt_file.cpp
index 75f8fb8..644447c 100644
--- a/utils/decrypt_file.cpp
+++ b/utils/decrypt_file.cpp
@@ -30,27 +30,24 @@ namespace
 
     void decrypt_file(const Settings& settings)
     {
-        const auto algorithm = settings.get_algorithm();
-        const auto mode = settings.get_mode();
-
-        const auto& ciphertext_path = settings.get_input_path();
-        const auto& plaintext_path = settings.get_output_path();
+        const auto& algorithm = settings.algorithm;
+        const auto& mode = settings.mode;
 
         aes::Box::Key key;
-        aes::Box::parse_key(key, algorithm, settings.get_key_string());
+        aes::Box::parse_key(key, algorithm, settings.key);
 
-        if (aes::mode_requires_initialization_vector(mode))
+        if (aes::mode_requires_init_vector(mode))
         {
             aes::Box::Block iv;
-            aes::Box::parse_block(iv, algorithm, settings.get_iv_string());
-            aes::Box box{algorithm, key, mode, iv};
+            aes::Box::parse_block(iv, algorithm, settings.iv);
 
-            decrypt_file(box, ciphertext_path, plaintext_path);
+            aes::Box box{algorithm, key, mode, iv};
+            decrypt_file(box, settings.input_path, settings.output_path);
         }
         else
         {
             aes::Box box{algorithm, key};
-            decrypt_file(box, ciphertext_path, plaintext_path);
+            decrypt_file(box, settings.input_path, settings.output_path);
         }
     }
 }
@@ -59,11 +56,10 @@ int main(int argc, char** argv)
 {
     try
     {
-        CommandLineParser cmd_parser(argv[0]);
+        CommandLineParser cmd_parser{argv[0]};
         try
         {
-            Settings settings;
-            cmd_parser.parse(settings, argc, argv);
+            const auto settings = cmd_parser.parse(argc, argv);
 
             if (cmd_parser.exit_with_usage())
             {
diff --git a/utils/encrypt_block.cpp b/utils/encrypt_block.cpp
index 714dab7..340e18b 100644
--- a/utils/encrypt_block.cpp
+++ b/utils/encrypt_block.cpp
@@ -25,7 +25,7 @@ namespace
     {
         typename aes::Types<algorithm>::Block iv;
 
-        if (aes::ModeRequiresInitializationVector<mode>::value)
+        if (aes::ModeRequiresInitVector<mode>::value)
         {
             aes::from_string<algorithm>(iv, input.get_iv_string());
             if (verbose)
@@ -144,7 +144,7 @@ namespace
         aes::Box::Key key;
         aes::Box::parse_key(key, algorithm, input.get_key_string());
 
-        if (aes::mode_requires_initialization_vector(mode))
+        if (aes::mode_requires_init_vector(mode))
         {
             aes::Box::Block iv;
             aes::Box::parse_block(iv, algorithm, input.get_iv_string());
@@ -164,12 +164,11 @@ int main(int argc, char** argv)
 {
     try
     {
-        CommandLineParser cmd_parser(argv[0]);
+        CommandLineParser cmd_parser{argv[0]};
         try
         {
             std::vector<Input> inputs;
-            Settings settings;
-            cmd_parser.parse(settings, argc, argv, inputs);
+            const auto settings = cmd_parser.parse(argc, argv, inputs);
 
             if (cmd_parser.exit_with_usage())
             {
@@ -179,20 +178,20 @@ int main(int argc, char** argv)
 
             for (const auto& input : inputs)
             {
-                if (settings.use_boxes())
+                if (settings.use_boxes)
                 {
                     encrypt_using_boxes(
-                        settings.get_algorithm(),
-                        settings.get_mode(),
+                        settings.algorithm,
+                        settings.mode,
                         input);
                 }
                 else
                 {
                     encrypt_using_cxx_api(
-                        settings.get_algorithm(),
-                        settings.get_mode(),
+                        settings.algorithm,
+                        settings.mode,
                         input,
-                        settings.verbose());
+                        settings.verbose);
                 }
             }
         }
diff --git a/utils/encrypt_bmp.cpp b/utils/encrypt_bmp.cpp
index ac6cb92..ad61266 100644
--- a/utils/encrypt_bmp.cpp
+++ b/utils/encrypt_bmp.cpp
@@ -31,27 +31,24 @@ namespace
 
     void encrypt_bmp(const Settings& settings)
     {
-        const auto algorithm = settings.get_algorithm();
-        const auto mode = settings.get_mode();
-
-        const auto& plaintext_path = settings.get_input_path();
-        const auto& ciphertext_path = settings.get_output_path();
+        const auto& algorithm = settings.algorithm;
+        const auto& mode = settings.mode;
 
         aes::Box::Key key;
-        aes::Box::parse_key(key, algorithm, settings.get_key_string());
+        aes::Box::parse_key(key, algorithm, settings.key);
 
-        if (aes::mode_requires_initialization_vector(mode))
+        if (aes::mode_requires_init_vector(mode))
         {
             aes::Box::Block iv;
-            aes::Box::parse_block(iv, algorithm, settings.get_iv_string());
-            aes::Box box{algorithm, key, mode, iv};
+            aes::Box::parse_block(iv, algorithm, settings.iv);
 
-            encrypt_bmp(box, plaintext_path, ciphertext_path);
+            aes::Box box{algorithm, key, mode, iv};
+            encrypt_bmp(box, settings.input_path, settings.output_path);
         }
         else
         {
             aes::Box box{algorithm, key};
-            encrypt_bmp(box, plaintext_path, ciphertext_path);
+            encrypt_bmp(box, settings.input_path, settings.output_path);
         }
     }
 }
@@ -60,11 +57,10 @@ int main(int argc, char** argv)
 {
     try
     {
-        CommandLineParser cmd_parser(argv[0]);
+        CommandLineParser cmd_parser{argv[0]};
         try
         {
-            Settings settings;
-            cmd_parser.parse(settings, argc, argv);
+            const auto settings = cmd_parser.parse(argc, argv);
 
             if (cmd_parser.exit_with_usage())
             {
diff --git a/utils/encrypt_file.cpp b/utils/encrypt_file.cpp
index 9a4ee5c..007ed18 100644
--- a/utils/encrypt_file.cpp
+++ b/utils/encrypt_file.cpp
@@ -30,27 +30,24 @@ namespace
 
     void encrypt_file(const Settings& settings)
     {
-        const auto algorithm = settings.get_algorithm();
-        const auto mode = settings.get_mode();
-
-        const auto& plaintext_path = settings.get_input_path();
-        const auto& ciphertext_path = settings.get_output_path();
+        const auto& algorithm = settings.algorithm;
+        const auto& mode = settings.mode;
 
         aes::Box::Key key;
-        aes::Box::parse_key(key, algorithm, settings.get_key_string());
+        aes::Box::parse_key(key, algorithm, settings.key);
 
-        if (aes::mode_requires_initialization_vector(mode))
+        if (aes::mode_requires_init_vector(mode))
         {
             aes::Box::Block iv;
-            aes::Box::parse_block(iv, algorithm, settings.get_iv_string());
-            aes::Box box{algorithm, key, mode, iv};
+            aes::Box::parse_block(iv, algorithm, settings.iv);
 
-            encrypt_file(box, plaintext_path, ciphertext_path);
+            aes::Box box{algorithm, key, mode, iv};
+            encrypt_file(box, settings.input_path, settings.output_path);
         }
         else
         {
             aes::Box box{algorithm, key};
-            encrypt_file(box, plaintext_path, ciphertext_path);
+            encrypt_file(box, settings.input_path, settings.output_path);
         }
     }
 }
@@ -59,11 +56,10 @@ int main(int argc, char** argv)
 {
     try
     {
-        CommandLineParser cmd_parser(argv[0]);
+        CommandLineParser cmd_parser{argv[0]};
         try
         {
-            Settings settings;
-            cmd_parser.parse(settings, argc, argv);
+            const auto settings = cmd_parser.parse(argc, argv);
 
             if (cmd_parser.exit_with_usage())
             {
diff --git a/utils/file_cmd_parser.hpp b/utils/file_cmd_parser.hpp
index c755c7a..0a6423f 100644
--- a/utils/file_cmd_parser.hpp
+++ b/utils/file_cmd_parser.hpp
@@ -23,49 +23,42 @@ namespace
     class Settings
     {
     public:
-        Settings() = default;
-
-        aes::Mode get_mode() const { return mode; }
-        aes::Algorithm get_algorithm() const { return algorithm; }
-
-        const std::string& get_input_path() const { return input_path; }
-        const std::string& get_output_path() const { return output_path; }
-
-        const std::string& get_key_string() const { return key; }
-        const std::string& get_iv_string() const { return iv; }
-
-    private:
-        aes::Mode mode;
-        aes::Algorithm algorithm;
+        aes::Algorithm algorithm = AES_AES128;
+        aes::Mode mode = AES_ECB;
 
         std::string input_path;
         std::string output_path;
         std::string key;
         std::string iv;
 
+    private:
+        Settings() = default;
+
         friend class CommandLineParser;
     };
 
     class CommandLineParser
     {
     public:
-        CommandLineParser(const std::string& argv0)
-            : prog_name(boost::filesystem::path(argv0).filename().string())
-            , options("Options")
+        explicit CommandLineParser(const std::string& argv0)
+            : prog_name{boost::filesystem::path{argv0}.filename().string()}
+            , options{"Options"}
         { }
 
-        void parse(Settings& settings, int argc, char** argv)
+        Settings parse(int argc, char** argv)
         {
+            Settings settings;
+
             namespace po = boost::program_options;
 
             options.add_options()
                 ("help,h", "show this message and exit")
-                ("mode,m", po::value<aes::Mode>(&settings.mode)->required(), "set mode of operation")
-                ("algorithm,a", po::value<aes::Algorithm>(&settings.algorithm)->required(), "set algorithm")
-                ("input-path,i", po::value<std::string>(&settings.input_path)->required(), "set input file path")
+                ("mode,m",        po::value<aes::Mode>(&settings.mode)->required(), "set mode of operation")
+                ("algorithm,a",   po::value<aes::Algorithm>(&settings.algorithm)->required(), "set algorithm")
+                ("input-path,i",  po::value<std::string>(&settings.input_path)->required(), "set input file path")
                 ("output-path,o", po::value<std::string>(&settings.output_path)->required(), "set output file path")
-                ("key,k", po::value<std::string>(&settings.key)->required(), "set encryption key")
-                ("iv,v", po::value<std::string>(&settings.iv), "set initialization vector");
+                ("key,k",         po::value<std::string>(&settings.key)->required(), "set encryption key")
+                ("iv,v",          po::value<std::string>(&settings.iv), "set initialization vector");
 
             po::variables_map vm;
             po::store(po::parse_command_line(argc, argv, options), vm);
@@ -73,12 +66,12 @@ namespace
             if (vm.count("help"))
             {
                 help_flag = true;
-                return;
+                return settings;
             }
 
             po::notify(vm);
 
-            if (aes::mode_requires_initialization_vector(settings.get_mode()))
+            if (aes::mode_requires_init_vector(settings.mode))
             {
                 if (!vm.count("iv"))
                 {
@@ -86,6 +79,8 @@ namespace
                         "an initialization vector is required for the selected mode of operation");
                 }
             }
+
+            return settings;
         }
 
         bool exit_with_usage() const { return help_flag; }