From 7988cc406d452ce6f22bcb7c32023e9e758bd7a0 Mon Sep 17 00:00:00 2001
From: Sebastian Messmer <mail@smessmer.de>
Date: Sat, 24 Oct 2015 12:25:49 +0200
Subject: [PATCH] Added serialization/deserialization of DerivedKeyConfig

---
 src/config/crypto/DerivedKeyConfig.cpp      | 31 ++++++++++++
 src/config/crypto/DerivedKeyConfig.h        |  5 ++
 test/config/crypto/DerivedKeyConfigTest.cpp | 52 +++++++++++++++++----
 3 files changed, 80 insertions(+), 8 deletions(-)

diff --git a/src/config/crypto/DerivedKeyConfig.cpp b/src/config/crypto/DerivedKeyConfig.cpp
index 12fde801..b5acf89c 100644
--- a/src/config/crypto/DerivedKeyConfig.cpp
+++ b/src/config/crypto/DerivedKeyConfig.cpp
@@ -1 +1,32 @@
 #include "DerivedKeyConfig.h"
+#include <messmer/cpp-utils/assert/assert.h>
+
+using std::istream;
+using std::ostream;
+using cpputils::Data;
+
+namespace cryfs {
+    void DerivedKeyConfig::save(ostream &stream) const {
+        uint8_t saltSize = _salt.size();
+        ASSERT(saltSize < std::numeric_limits<uint8_t>::max(), "We don't support salts bigger than 256 byte");
+        stream.write(reinterpret_cast<const char *>(&saltSize), sizeof(saltSize));
+        stream.write(static_cast<const char *>(_salt.data()), saltSize);
+        stream.write(reinterpret_cast<const char *>(&_N), sizeof(_N));
+        stream.write(reinterpret_cast<const char *>(&_r), sizeof(_r));
+        stream.write(reinterpret_cast<const char *>(&_p), sizeof(_p));
+    }
+
+    DerivedKeyConfig DerivedKeyConfig::load(istream &stream) {
+        uint8_t saltSize;
+        stream.read(reinterpret_cast<char *>(&saltSize), sizeof(saltSize));
+        Data salt(saltSize);
+        stream.read(static_cast<char *>(salt.data()), saltSize);
+        decltype(_N) N;
+        stream.read(reinterpret_cast<char *>(&N), sizeof(_N));
+        decltype(_r) r;
+        stream.read(reinterpret_cast<char *>(&r), sizeof(_r));
+        decltype(_p) p;
+        stream.read(reinterpret_cast<char *>(&p), sizeof(_p));
+        return DerivedKeyConfig(std::move(salt), N, r, p);
+    }
+}
diff --git a/src/config/crypto/DerivedKeyConfig.h b/src/config/crypto/DerivedKeyConfig.h
index 55f86dc1..af62d15c 100644
--- a/src/config/crypto/DerivedKeyConfig.h
+++ b/src/config/crypto/DerivedKeyConfig.h
@@ -3,6 +3,7 @@
 #define MESSMER_CRYFS_SRC_CONFIG_CRYPTO_KEYCONFIG_H
 
 #include <messmer/cpp-utils/data/Data.h>
+#include <iostream>
 
 namespace cryfs {
 
@@ -30,6 +31,10 @@ namespace cryfs {
             return _p;
         }
 
+        void save(std::ostream &stream) const;
+
+        static DerivedKeyConfig load(std::istream &stream);
+
     private:
         cpputils::Data _salt;
         uint64_t _N;
diff --git a/test/config/crypto/DerivedKeyConfigTest.cpp b/test/config/crypto/DerivedKeyConfigTest.cpp
index e4c92e4c..de48054f 100644
--- a/test/config/crypto/DerivedKeyConfigTest.cpp
+++ b/test/config/crypto/DerivedKeyConfigTest.cpp
@@ -1,51 +1,87 @@
 #include <google/gtest/gtest.h>
 #include "../../../src/config/crypto/DerivedKeyConfig.h"
 #include <messmer/cpp-utils/data/DataFixture.h>
+#include <sstream>
 
 using namespace cryfs;
 using cpputils::DataFixture;
 using cpputils::Data;
+using std::stringstream;
 
-TEST(DerivedKeyConfigTest, Salt) {
+class DerivedKeyConfigTest : public ::testing::Test {
+public:
+    DerivedKeyConfig SaveAndLoad(const DerivedKeyConfig &source) {
+        stringstream str;
+        source.save(str);
+        return DerivedKeyConfig::load(str);
+    }
+};
+
+TEST_F(DerivedKeyConfigTest, Salt) {
     DerivedKeyConfig cfg(DataFixture::generate(32), 0, 0, 0);
     EXPECT_EQ(DataFixture::generate(32), cfg.salt());
 }
 
-TEST(DerivedKeyConfigTest, Salt_Move) {
+TEST_F(DerivedKeyConfigTest, Salt_Move) {
     DerivedKeyConfig cfg(DataFixture::generate(32), 0, 0, 0);
     DerivedKeyConfig moved = std::move(cfg);
     EXPECT_EQ(DataFixture::generate(32), moved.salt());
 }
 
-TEST(DerivedKeyConfigTest, N) {
+TEST_F(DerivedKeyConfigTest, Salt_SaveAndLoad) {
+    DerivedKeyConfig cfg(DataFixture::generate(32), 0, 0, 0);
+    DerivedKeyConfig loaded = SaveAndLoad(cfg);
+    EXPECT_EQ(DataFixture::generate(32), loaded.salt());
+}
+
+TEST_F(DerivedKeyConfigTest, N) {
     DerivedKeyConfig cfg(Data(0), 1024, 0, 0);
     EXPECT_EQ(1024, cfg.N());
 }
 
-TEST(DerivedKeyConfigTest, N_Move) {
+TEST_F(DerivedKeyConfigTest, N_Move) {
     DerivedKeyConfig cfg(Data(0), 1024, 0, 0);
     DerivedKeyConfig moved = std::move(cfg);
     EXPECT_EQ(1024, moved.N());
 }
 
-TEST(DerivedKeyConfigTest, r) {
+TEST_F(DerivedKeyConfigTest, N_SaveAndLoad) {
+    DerivedKeyConfig cfg(Data(0), 1024, 0, 0);
+    DerivedKeyConfig loaded = SaveAndLoad(cfg);
+    EXPECT_EQ(1024, loaded.N());
+}
+
+TEST_F(DerivedKeyConfigTest, r) {
     DerivedKeyConfig cfg(Data(0), 0, 8, 0);
     EXPECT_EQ(8, cfg.r());
 }
 
-TEST(DerivedKeyConfigTest, r_Move) {
+TEST_F(DerivedKeyConfigTest, r_Move) {
     DerivedKeyConfig cfg(Data(0), 0, 8, 0);
     DerivedKeyConfig moved = std::move(cfg);
     EXPECT_EQ(8, moved.r());
 }
 
-TEST(DerivedKeyConfigTest, p) {
+TEST_F(DerivedKeyConfigTest, r_SaveAndLoad) {
+    DerivedKeyConfig cfg(Data(0), 0, 8, 0);
+    DerivedKeyConfig loaded = SaveAndLoad(cfg);
+    EXPECT_EQ(8, loaded.r());
+}
+
+TEST_F(DerivedKeyConfigTest, p) {
     DerivedKeyConfig cfg(Data(0), 0, 0, 16);
     EXPECT_EQ(16, cfg.p());
 }
 
-TEST(DerivedKeyConfigTest, p_Move) {
+TEST_F(DerivedKeyConfigTest, p_Move) {
     DerivedKeyConfig cfg(Data(0), 0, 0, 16);
     DerivedKeyConfig moved = std::move(cfg);
     EXPECT_EQ(16, moved.p());
 }
+
+
+TEST_F(DerivedKeyConfigTest, p_SaveAndLoad) {
+    DerivedKeyConfig cfg(Data(0), 0, 0, 16);
+    DerivedKeyConfig loaded = SaveAndLoad(cfg);
+    EXPECT_EQ(16, loaded.p());
+}
\ No newline at end of file