1 files changed, 195 insertions, 0 deletions
diff --git a/utils/decrypt_file.cpp b/utils/decrypt_file.cpp
new file mode 100644
index 0000000..3e08d6f
--- /dev/null
+++ b/utils/decrypt_file.cpp
@@ -0,0 +1,195 @@
+/**
+ * \file
+ * \author Egor Tensin <Egor.Tensin@gmail.com>
+ * \date 2015
+ * \copyright This file is licensed under the terms of the MIT License.
+ *            See LICENSE.txt for details.
+ */
+
+#include "file_common.hpp"
+
+#include <aesni/all.h>
+
+#include <aesnixx/all.hpp>
+
+#include <boost/program_options.hpp>
+
+#include <cstdlib>
+
+#include <deque>
+#include <exception>
+#include <fstream>
+#include <iostream>
+#include <string>
+#include <utility>
+#include <vector>
+
+namespace
+{
+    std::ifstream::pos_type get_file_size(const std::string& path)
+    {
+        std::ifstream ifs;
+        ifs.exceptions(std::ifstream::badbit | std::ifstream::failbit);
+        ifs.open(path, std::ifstream::binary | std::ifstream::ate);
+        return ifs.tellg();
+    }
+
+    std::vector<char> read_file(const std::string& path)
+    {
+        const auto size = static_cast<std::size_t>(get_file_size(path));
+
+        std::ifstream ifs;
+        ifs.exceptions(std::ifstream::badbit | std::ifstream::failbit);
+        ifs.open(path, std::ifstream::binary);
+
+        std::vector<char> src_buf;
+        src_buf.reserve(size);
+        src_buf.assign(std::istreambuf_iterator<char>(ifs),
+                       std::istreambuf_iterator<char>());
+        return src_buf;
+    }
+
+    void write_file(const std::string& path, const std::vector<char>& src)
+    {
+        std::ofstream ofs;
+        ofs.exceptions(std::ofstream::badbit | std::ofstream::failbit);
+        ofs.open(path, std::ofstream::binary);
+        ofs.write(src.data(), src.size());
+    }
+
+    template <aesni::Algorithm algorithm>
+    bool decrypt_file_with_algorithm(
+        const AesNI_BoxAlgorithmParams& algorithm_params,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
+    {
+        AesNI_BoxBlock iv;
+        AesNI_BoxBlock* iv_ptr = nullptr;
+
+        if (aesni::mode_requires_initialization_vector(mode))
+        {
+            if (args.empty())
+                return false;
+
+            aesni::from_string<algorithm>(iv.aes_block, args.front());
+            iv_ptr = &iv;
+            args.pop_front();
+        }
+
+        if (args.size() != 2)
+            return false;
+
+        const auto src_path = args[0];
+        const auto dest_path = args[1];
+
+        const auto src_buf = read_file(src_path);
+
+        AesNI_Box box;
+
+        aesni_box_init(
+            &box,
+            algorithm,
+            &algorithm_params,
+            mode,
+            iv_ptr,
+            aesni::ErrorDetailsThrowsInDestructor());
+
+        std::size_t dest_size;
+
+        aesni_box_decrypt_buffer(
+            &box,
+            src_buf.data(),
+            src_buf.size(),
+            nullptr,
+            &dest_size,
+            aesni::ErrorDetailsThrowsInDestructor());
+
+        std::vector<char> dest_buf;
+        dest_buf.resize(dest_size);
+
+        aesni_box_decrypt_buffer(
+            &box,
+            src_buf.data(),
+            src_buf.size(),
+            dest_buf.data(),
+            &dest_size,
+            aesni::ErrorDetailsThrowsInDestructor());
+
+        dest_buf.resize(dest_size);
+        write_file(dest_path, dest_buf);
+
+        return true;
+    }
+
+    bool decrypt_file(
+        aesni::Algorithm algorithm,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
+    {
+        if (args.empty())
+            return false;
+
+        AesNI_BoxAlgorithmParams algorithm_params;
+
+        switch (algorithm)
+        {
+            case AESNI_AES128:
+                aesni::from_string<AESNI_AES128>(
+                    algorithm_params.aes128_key, args.front());
+                args.pop_front();
+                return decrypt_file_with_algorithm<AESNI_AES128>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES192:
+                aesni::from_string<AESNI_AES192>(
+                    algorithm_params.aes192_key, args.front());
+                args.pop_front();
+                return decrypt_file_with_algorithm<AESNI_AES192>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES256:
+                aesni::from_string<AESNI_AES256>(
+                    algorithm_params.aes256_key, args.front());
+                args.pop_front();
+                return decrypt_file_with_algorithm<AESNI_AES256>(
+                    algorithm_params, mode, args);
+
+            default:
+                return false;
+        }
+    }
+}
+
+int main(int argc, char** argv)
+{
+    try
+    {
+        CommandLineParser cmd_parser("decrypt_file.exe");
+
+        if (!cmd_parser.parse_options(argc, argv))
+            return 0;
+
+        if (!decrypt_file(cmd_parser.get_algorithm(), cmd_parser.get_mode(), cmd_parser.get_args()))
+        {
+            cmd_parser.print_usage();
+            return 1;
+        }
+
+        return 0;
+    }
+    catch (const boost::program_options::error& e)
+    {
+        std::cerr << "Usage error: " << e.what() << "\n";
+        return 1;
+    }
+    catch (const aesni::Error& e)
+    {
+        std::cerr << e;
+        return 1;
+    }
+    catch (const std::exception& e)
+    {
+        std::cerr << e.what() << "\n";
+        return 1;
+    }
+}