1 files changed, 91 insertions, 0 deletions
diff --git a/aesxx/utils/decrypt_file.cpp b/aesxx/utils/decrypt_file.cpp
new file mode 100644
index 0000000..6da3d17
--- /dev/null
+++ b/aesxx/utils/decrypt_file.cpp
@@ -0,0 +1,91 @@
+// Copyright (c) 2015 Egor Tensin <Egor.Tensin@gmail.com>
+// This file is part of the "AES tools" project.
+// For details, see https://github.com/egor-tensin/aes-tools.
+// Distributed under the MIT License.
+
+#include "file_cmd_parser.hpp"
+#include "helpers/file.hpp"
+
+#include <aesxx/all.hpp>
+
+#include <boost/program_options.hpp>
+
+#include <exception>
+#include <iostream>
+#include <string>
+#include <vector>
+
+namespace
+{
+    void decrypt_file(
+        aes::Box& box,
+        const std::string& ciphertext_path,
+        const std::string& plaintext_path)
+    {
+        const auto ciphertext_buf = file::read_file(ciphertext_path);
+        const auto plaintext_buf = box.decrypt_buffer(
+            ciphertext_buf.data(),
+            ciphertext_buf.size());
+        file::write_file(plaintext_path, plaintext_buf);
+    }
+
+    void decrypt_file(const FileSettings& settings)
+    {
+        const auto& algorithm = settings.algorithm;
+        const auto& mode = settings.mode;
+
+        aes::Box::Key key;
+        aes::Box::parse_key(key, algorithm, settings.key);
+
+        if (aes::mode_requires_init_vector(mode))
+        {
+            aes::Box::Block iv;
+            aes::Box::parse_block(iv, algorithm, settings.iv);
+
+            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, settings.input_path, settings.output_path);
+        }
+    }
+}
+
+int main(int argc, char** argv)
+{
+    try
+    {
+        FileSettings settings{argv[0]};
+
+        try
+        {
+            settings.parse(argc, argv);
+        }
+        catch (const boost::program_options::error& e)
+        {
+            settings.usage_error(e);
+            return 1;
+        }
+
+        if (settings.exit_with_usage)
+        {
+            settings.usage();
+            return 0;
+        }
+
+        decrypt_file(settings);
+    }
+    catch (const aes::Error& e)
+    {
+        std::cerr << e;
+        return 1;
+    }
+    catch (const std::exception& e)
+    {
+        std::cerr << e.what() << "\n";
+        return 1;
+    }
+    return 0;
+}