Library for the AES-CBC en/decryption of 4K blocks

The 'aes_cbc_4k' library is simple wrapper around libsparkcrypto to
serve as a backend for storage encryption. It operates on data chunks of
4 KiB and uses AES-CBC while incorporating the block number and the
private key as salt values.

repos/gems/src/test/aes_cbc_4k/main.cc

@@ -0,0 +1,90 @@
+/*
+ * \brief  Test for using libsparkcrypto
+ * \author Norman Feske
+ * \date   2018-12-20
+ */
+
+/*
+ * Copyright (C) 2018 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+/* Genode includes */
+#include <base/component.h>
+#include <base/attached_rom_dataspace.h>
+
+#include <aes_cbc_4k/aes_cbc_4k.h>
+
+namespace Test {
+	struct Main;
+	using namespace Genode;
+}
+
+
+namespace Genode {
+
+	static inline void print(Output &out, Aes_cbc_4k::Ciphertext const &data)
+	{
+		constexpr unsigned NUM_LINES      = 10;
+		constexpr unsigned BYTES_PER_LINE = 32;
+
+		for (unsigned line = 0; line < NUM_LINES; line++) {
+
+			for (unsigned i = 0; i < BYTES_PER_LINE; i++)
+				print(out, Genode::Hex(data.values[line*BYTES_PER_LINE + i],
+				                       Genode::Hex::OMIT_PREFIX,
+				                       Genode::Hex::PAD));
+			if (line + 1 < NUM_LINES)
+				print(out, "\n");
+		}
+	}
+}
+
+
+struct Test::Main
+{
+	Env &_env;
+
+	Attached_rom_dataspace _plaintext { _env, "plaintext" };
+	Attached_rom_dataspace _key       { _env, "key" };
+
+	Aes_cbc_4k::Ciphertext _ciphertext { };
+	Aes_cbc_4k::Plaintext  _decrypted_plaintext  { };
+
+	Main(Env &env) : _env(env)
+	{
+		Aes_cbc_4k::Block_number const block_number { 0 };
+
+		Aes_cbc_4k::Key       const &key       = *_key.local_addr<Aes_cbc_4k::Key>();
+		Aes_cbc_4k::Plaintext const &plaintext = *_plaintext.local_addr<Aes_cbc_4k::Plaintext>();
+
+		Aes_cbc_4k::encrypt(key, block_number, plaintext, _ciphertext);
+
+		log("ciphertext:\n", _ciphertext);
+
+		Aes_cbc_4k::decrypt(key, block_number, _ciphertext, _decrypted_plaintext);
+
+		/* compare decrypted ciphertext with original plaintext */
+		if (memcmp(plaintext.values, _decrypted_plaintext.values, sizeof(plaintext))) {
+			error("plaintext differs from decrypted ciphertext");
+			return;
+		}
+
+		log("Test succeeded");
+	}
+};
+
+
+Genode::Env *__genode_env;
+
+
+void Component::construct(Genode::Env &env)
+{
+	/* make ada-runtime happy */
+	__genode_env = &env;
+	env.exec_static_constructors();
+
+	static Test::Main inst(env);
+}

repos/gems/src/test/aes_cbc_4k/target.mk

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+TARGET := test-aes_cbc_4k
+SRC_CC := main.cc
+LIBS   += base aes_cbc_4k