Only show update check warning if version on server is actually newer

src/cryfs/CMakeLists.txt

@@ -3,6 +3,7 @@ project (cryfs)
 set(SOURCES
     cli/Cli.cpp
     cli/VersionChecker.cpp
+    cli/VersionCompare.cpp
     cli/CallAfterTimeout.cpp
     cli/program_options/utils.cpp
     cli/program_options/ProgramOptions.cpp

src/cryfs/cli/Cli.cpp

@@ -21,6 +21,7 @@
 #include <cryfs/filesystem/CryDir.h>
 
 #include "VersionChecker.h"
+#include "VersionCompare.h"
 
 //TODO Fails with gpg-homedir in filesystem: gpg --homedir gpg-homedir --gen-key
 //TODO Many functions accessing the ProgramOptions object. Factor out into class that stores it as a member.
@@ -90,8 +91,8 @@ namespace cryfs {
         VersionChecker versionChecker(_httpClient);
         optional<string> newestVersion = versionChecker.newestVersion();
         if (newestVersion == none) {
-            cout << "Could not connect to cryfs.org to check for updates." << endl;
-        } else if (*newestVersion != version::VERSION_STRING) {
+            cout << "Could not check for updates." << endl;
+        } else if (VersionCompare::isOlderThan(version::VERSION_STRING, *newestVersion)) {
             cout << "CryFS " << *newestVersion << " is released. Please update." << endl;
         }
         optional<string> securityWarning = versionChecker.securityWarningFor(version::VERSION_STRING);

src/cryfs/cli/VersionCompare.cpp

@@ -0,0 +1,43 @@
+#include "VersionCompare.h"
+
+using std::string;
+
+namespace cryfs {
+
+    bool VersionCompare::isOlderThan(const string &v1, const string &v2) {
+        return _isOlderThanStartingFrom(v1, v2, 0, 0);
+    }
+
+    bool VersionCompare::_isOlderThanStartingFrom(const string &v1, const string &v2, size_t startPos1, size_t startPos2) {
+        if (startPos1 > v1.size() && startPos2 > v2.size()) {
+            // All components are equal
+            return false;
+        }
+        string componentStr1 = _extractComponent(v1, startPos1);
+        string componentStr2 = _extractComponent(v2, startPos2);
+        uint32_t component1 = _parseComponent(componentStr1);
+        uint32_t component2 = _parseComponent(componentStr2);
+        if (component1 == component2) {
+            return _isOlderThanStartingFrom(v1, v2, startPos1 + componentStr1.size() + 1, startPos2 + componentStr2.size() + 1);
+        }
+        return component1 < component2;
+    }
+
+    string VersionCompare::_extractComponent(const string &version, size_t startPos) {
+        if (startPos >= version.size()) {
+            return "";
+        }
+        size_t found = version.find('.', startPos);
+        if (found == string::npos) {
+            return version.substr(startPos);
+        }
+        return version.substr(startPos, found-startPos);
+    }
+
+    uint32_t VersionCompare::_parseComponent(const string &component) {
+        if (component == "" || component.substr(0, 3) == "dev") {
+            return 0;
+        }
+        return std::stoul(component);
+    }
+}

src/cryfs/cli/VersionCompare.h

@@ -0,0 +1,19 @@
+#pragma once
+#ifndef MESSMER_CRYFS_CLI_VERSIONCOMPARE_H
+#define MESSMER_CRYFS_CLI_VERSIONCOMPARE_H
+
+#include <string>
+
+namespace cryfs {
+    class VersionCompare {
+    public:
+        static bool isOlderThan(const std::string &v1, const std::string &v2);
+
+    private:
+        static bool _isOlderThanStartingFrom(const std::string &v1, const std::string &v2, size_t startPos1, size_t startPos2);
+        static std::string _extractComponent(const std::string &version, size_t startPos);
+        static uint32_t _parseComponent(const std::string &component);
+    };
+}
+
+#endif

test/cryfs/CMakeLists.txt

@@ -10,6 +10,7 @@ set(SOURCES
     cli/program_options/ParserTest.cpp
     cli/CliTest_ShowingHelp.cpp
     cli/VersionCheckerTest.cpp
+    cli/VersionCompareTest.cpp
     config/crypto/CryConfigEncryptorFactoryTest.cpp
     config/crypto/outer/OuterConfigTest.cpp
     config/crypto/outer/OuterEncryptorTest.cpp

test/cryfs/cli/VersionCompareTest.cpp

@@ -0,0 +1,54 @@
+#include <gtest/gtest.h>
+#include <cryfs/cli/VersionCompare.h>
+
+using namespace cryfs;
+using std::string;
+
+class VersionCompareTest : public ::testing::Test {
+public:
+    void EXPECT_IS_OLDER_THAN(const string &v1, const string &v2) {
+        EXPECT_TRUE(VersionCompare::isOlderThan(v1, v2));
+        EXPECT_FALSE(VersionCompare::isOlderThan(v2, v1));
+    }
+
+    void EXPECT_IS_SAME_AGE(const string &v1, const string &v2) {
+        EXPECT_FALSE(VersionCompare::isOlderThan(v1, v2));
+        EXPECT_FALSE(VersionCompare::isOlderThan(v2, v1));
+    }
+};
+
+TEST_F(VersionCompareTest, IsDifferentVersion) {
+    EXPECT_IS_OLDER_THAN("0.8", "0.8.1");
+    EXPECT_IS_OLDER_THAN("0.8", "1.0");
+    EXPECT_IS_OLDER_THAN("0.8", "1.0.1");
+    EXPECT_IS_OLDER_THAN("0.8.1", "1.0");
+    EXPECT_IS_OLDER_THAN("0.7.9", "0.8.0");
+    EXPECT_IS_OLDER_THAN("1.0.0", "1.0.1");
+    EXPECT_IS_OLDER_THAN("1.0.0.0", "1.0.0.1");
+    EXPECT_IS_OLDER_THAN("1", "1.0.0.1");
+    EXPECT_IS_OLDER_THAN("1.0.0.0", "1.1");
+}
+
+TEST_F(VersionCompareTest, IsSameVersion) {
+    EXPECT_IS_SAME_AGE("0.8", "0.8");
+    EXPECT_IS_SAME_AGE("1.0", "1.0");
+    EXPECT_IS_SAME_AGE("1", "1.0");
+    EXPECT_IS_SAME_AGE("1.0.0", "1.0.0");
+    EXPECT_IS_SAME_AGE("0.8", "0.8.0");
+    EXPECT_IS_SAME_AGE("1", "1.0.0.0");
+}
+
+TEST_F(VersionCompareTest, ZeroPrefix) {
+    EXPECT_IS_OLDER_THAN("1.00.0", "1.0.01");
+    EXPECT_IS_SAME_AGE("1.0.01", "1.0.1");
+    EXPECT_IS_SAME_AGE("01.0.01", "1.0.1");
+}
+
+TEST_F(VersionCompareTest, DevVersions) {
+    EXPECT_IS_OLDER_THAN("0.8", "0.8.1.dev1");
+    EXPECT_IS_OLDER_THAN("0.8.1", "0.8.2.dev2");
+    EXPECT_IS_OLDER_THAN("0.8.1.dev1", "0.8.2");
+    EXPECT_IS_OLDER_THAN("0.8.dev1", "0.8.1");
+    EXPECT_IS_OLDER_THAN("0.8.dev1", "0.9");
+    EXPECT_IS_SAME_AGE("0.9.1.dev5", "0.9.1");
+}