Check that base directory is not inside mount directory

src/Cli.cpp

@@ -25,6 +25,8 @@
 #error The used libc implementation has a maximal password size for getpass(). We cannot use it to ask for passwords.
 #endif
 
+//TODO Many functions accessing the ProgramOptions object. Factor out into class that stores it as a member.
+
 using namespace cryfs;
 namespace bf = boost::filesystem;
 
@@ -144,9 +146,40 @@ namespace cryfs {
     }
 
     void Cli::_sanityChecks(const ProgramOptions &options) {
-        if (bf::path(options.baseDir()) == bf::path(options.mountDir())) {
-            throw std::runtime_error("Can't mount into base directory");
+        _checkBasedirAccessible(options);
+        //TODO Check MountdirAccessible (incl. Permissions)
+        _checkMountdirDoesntContainBasedir(options);
+    }
+
+    void Cli::_checkBasedirAccessible(const ProgramOptions &options) {
+        if (!bf::exists(options.baseDir())) {
+            throw std::runtime_error("Base directory not found.");
         }
+        //TODO Check permissions
+    }
+
+    void Cli::_checkMountdirDoesntContainBasedir(const ProgramOptions &options) {
+        if (_pathContains(options.mountDir(), options.baseDir())) {
+            throw std::runtime_error("Base directory can't be inside the mount directory.");
+        }
+    }
+
+    bool Cli::_pathContains(const bf::path &parent, const bf::path &child) {
+        bf::path absParent = bf::canonical(parent);
+        bf::path current = bf::canonical(child);
+        if (absParent.empty() && current.empty()) {
+            return true;
+        }
+        while(!current.empty()) {
+            std::cout << absParent.c_str() << " cmp " << current.c_str() << std::endl;
+            if (bf::equivalent(current, absParent)) {
+                std::cout << "equals" << std::endl;
+                return true;
+            }
+            std::cout << "not equals" << std::endl;
+            current = current.parent_path();
+        }
+        return false;
     }
 
     int Cli::main(int argc, char *argv[]) {

src/Cli.h

@@ -21,6 +21,9 @@ namespace cryfs {
         static void _showVersion();
         static void _initLogfile(const program_options::ProgramOptions &options);
         static void _sanityChecks(const program_options::ProgramOptions &options);
+        static void _checkMountdirDoesntContainBasedir(const program_options::ProgramOptions &options);
+        static bool _pathContains(const boost::filesystem::path &parent, const boost::filesystem::path &child);
+        static void _checkBasedirAccessible(const program_options::ProgramOptions &options);
     };
 }
 

test/cli/CliTest_Setup.cpp

@@ -6,24 +6,24 @@ using cpputils::TempFile;
 using CliTest_Setup = CliTest;
 
 TEST_F(CliTest_Setup, NoSpecialOptions) {
-    EXPECT_RUN_SUCCESS({basedir->path().c_str(), mountdir->path().c_str()});
+    EXPECT_RUN_SUCCESS({basedir.c_str(), mountdir.c_str()});
 }
 
 TEST_F(CliTest_Setup, NotexistingLogfileGiven) {
     TempFile notexisting_logfile(false);
-    EXPECT_RUN_SUCCESS({basedir->path().c_str(), mountdir->path().c_str(), "--logfile", notexisting_logfile.path().c_str()});
+    EXPECT_RUN_SUCCESS({basedir.c_str(), mountdir.c_str(), "--logfile", notexisting_logfile.path().c_str()});
     //TODO Expect logfile is used (check logfile content)
 }
 
 TEST_F(CliTest_Setup, ExistingLogfileGiven) {
-    EXPECT_RUN_SUCCESS({basedir->path().c_str(), mountdir->path().c_str(), "--logfile", logfile.path().c_str()});
+    EXPECT_RUN_SUCCESS({basedir.c_str(), mountdir.c_str(), "--logfile", logfile.path().c_str()});
     //TODO Expect logfile is used (check logfile content)
 }
 
 TEST_F(CliTest_Setup, ConfigfileGiven) {
-    EXPECT_RUN_SUCCESS({"/home/user/baseDir", "--config", configfile.path().c_str(), "/home/user/mountDir"});
+    EXPECT_RUN_SUCCESS({basedir.c_str(), "--config", configfile.path().c_str(), mountdir.c_str()});
 }
 
 TEST_F(CliTest_Setup, FuseOptionGiven) {
-    EXPECT_RUN_SUCCESS({"/home/user/baseDir", "/home/user/mountDir", "--", "-f"});
+    EXPECT_RUN_SUCCESS({basedir.c_str(), mountdir.c_str(), "--", "-f"});
 }

test/cli/CliTest_ShowingHelp.cpp

@@ -7,7 +7,7 @@ TEST_F(CliTest_ShowingHelp, HelpLongOption) {
 }
 
 TEST_F(CliTest_ShowingHelp, HelpLongOptionTogetherWithOtherOptions) {
-    EXPECT_EXIT_WITH_HELP_MESSAGE({basedir->path().c_str(), mountdir->path().c_str(), "--help"});
+    EXPECT_EXIT_WITH_HELP_MESSAGE({basedir.c_str(), mountdir.c_str(), "--help"});
 }
 
 TEST_F(CliTest_ShowingHelp, HelpShortOption) {
@@ -15,7 +15,7 @@ TEST_F(CliTest_ShowingHelp, HelpShortOption) {
 }
 
 TEST_F(CliTest_ShowingHelp, HelpShortOptionTogetherWithOtherOptions) {
-    EXPECT_EXIT_WITH_HELP_MESSAGE({basedir->path().c_str(), mountdir->path().c_str(), "-h"});
+    EXPECT_EXIT_WITH_HELP_MESSAGE({basedir.c_str(), mountdir.c_str(), "-h"});
 }
 
 TEST_F(CliTest_ShowingHelp, MissingAllOptions) {
@@ -23,5 +23,5 @@ TEST_F(CliTest_ShowingHelp, MissingAllOptions) {
 }
 
 TEST_F(CliTest_ShowingHelp, MissingDir) {
-    EXPECT_EXIT_WITH_HELP_MESSAGE({basedir->path().c_str()});
+    EXPECT_EXIT_WITH_HELP_MESSAGE({basedir.c_str()});
 }

test/cli/CliTest_WrongEnvironment.cpp

@@ -38,7 +38,7 @@ public:
     }
 
     vector<const char*> args() {
-        vector<const char*> result = {basedir->path().c_str(), mountdir->path().c_str()};
+        vector<const char*> result = {basedir.c_str(), mountdir.c_str()};
         if (GetParam().externalConfigfile) {
             result.push_back("--config");
             result.push_back(configfile.path().c_str());
@@ -70,11 +70,41 @@ TEST_P(CliTest_WrongEnvironment, NoErrorCondition) {
 
 TEST_P(CliTest_WrongEnvironment, MountDirIsBaseDir) {
     mountdir = basedir;
-    Test_Run_Error("Error: Can't mount into base directory");
+    Test_Run_Error("Error: Base directory can't be inside the mount directory");
+}
+
+bf::path make_relative(const bf::path &path) {
+    bf::path result;
+    bf::path cwd = bf::current_path();
+    for(auto iter = ++cwd.begin(); iter!=cwd.end(); ++iter) {
+        result /= "..";
+    }
+    result /= path;
+    return result;
+}
+
+TEST_P(CliTest_WrongEnvironment, MountDirIsBaseDir_MountDirRelative) {
+    mountdir = make_relative(basedir);
+    std::cout << basedir.c_str() << " --- " << mountdir.c_str();
+    Test_Run_Error("Error: Base directory can't be inside the mount directory");
+}
+
+TEST_P(CliTest_WrongEnvironment, MountDirIsBaseDir_BaseDirRelative) {
+    mountdir = basedir;
+    basedir = make_relative(basedir);
+    std::cout << basedir.c_str() << " --- " << mountdir.c_str();
+    Test_Run_Error("Error: Base directory can't be inside the mount directory");
+}
+
+TEST_P(CliTest_WrongEnvironment, MountDirIsBaseDir_BothRelative) {
+    basedir = make_relative(basedir);
+    mountdir = basedir;
+    std::cout << basedir.c_str() << " --- " << mountdir.c_str();
+    Test_Run_Error("Error: Base directory can't be inside the mount directory");
 }
 
 TEST_P(CliTest_WrongEnvironment, BaseDir_DoesntExist) {
-    basedir->remove();
+    _basedir.remove();
     Test_Run_Error("Error: Base directory not found");
 }
 

test/cli/testutils/CliTest.h

@@ -9,10 +9,12 @@
 
 class CliTest : public ::testing::Test {
 public:
-    CliTest(): basedir(std::make_shared<cpputils::TempDir>()), mountdir(std::make_shared<cpputils::TempDir>()), logfile(), configfile(false) {}
+    CliTest(): _basedir(), _mountdir(), basedir(_basedir.path()), mountdir(_mountdir.path()), logfile(), configfile(false) {}
 
-    std::shared_ptr<cpputils::TempDir> basedir;
-    std::shared_ptr<cpputils::TempDir> mountdir;
+    cpputils::TempDir _basedir;
+    cpputils::TempDir _mountdir;
+    boost::filesystem::path basedir;
+    boost::filesystem::path mountdir;
     cpputils::TempFile logfile;
     cpputils::TempFile configfile;