From 2b751fe84ebb2850ecea4735dee460cf61af34e5 Mon Sep 17 00:00:00 2001
From: Peter Sykora <psykora@gmail.com>
Date: Sat, 31 Mar 2018 23:43:47 +0200
Subject: [PATCH] [impl] Check if the file from download cache really exists
 before returning it

[impl] Remove downloaded update file if checksum is invalid
---
 src/CachedDownloader.cpp | 24 +++++++++++++-----------
 src/ModuleManager.cpp    |  1 +
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/CachedDownloader.cpp b/src/CachedDownloader.cpp
index bfc4cdd..bdd6060 100644
--- a/src/CachedDownloader.cpp
+++ b/src/CachedDownloader.cpp
@@ -66,20 +66,22 @@ boost::filesystem::path CachedDownloader::download(const std::string & url)
     auto it = m_cache.find(url);
     if (it != m_cache.end())
     {
-        return m_cacheDir / it->second;
-    }
-    else
-    {
-        auto fileName = boost::filesystem::unique_path();
-        auto tmpFile = m_cacheDir / fileName;
+        auto cachedFilename = m_cacheDir / it->second;
+        if (boost::filesystem::exists(cachedFilename))
         {
-            std::ofstream os(tmpFile.string(), std::ofstream::binary);
-            m_httpClient.get(url, os);
+            return cachedFilename;
         }
-        m_cache[url] = fileName.string();
-        addToCache(m_cacheDir / cacheListFilename, url, fileName.string());
-        return tmpFile;
     }
+
+    auto fileName = boost::filesystem::unique_path();
+    auto tmpFile = m_cacheDir / fileName;
+    {
+        std::ofstream os(tmpFile.string(), std::ofstream::binary);
+        m_httpClient.get(url, os);
+    }
+    m_cache[url] = fileName.string();
+    addToCache(m_cacheDir / cacheListFilename, url, fileName.string());
+    return tmpFile;
 }
 
 void CachedDownloader::clearCache()
diff --git a/src/ModuleManager.cpp b/src/ModuleManager.cpp
index ab78dae..064b023 100644
--- a/src/ModuleManager.cpp
+++ b/src/ModuleManager.cpp
@@ -27,6 +27,7 @@ void ModuleManager::applyUpdate(Module & module, const ModuleUpdate & update)
     auto hash = calcSHA256(updatePath);
     if (hash != boost::algorithm::to_upper_copy(update.checksum))
     {
+        fs::remove(updatePath);
         throw std::runtime_error("Integrity check of the update has failed");
     }