[pull] master from PowerDNS:master

pdns/credentials.cc

@@ -56,10 +56,41 @@ static std::string const pwhash_prefix = "$scrypt$";
 static size_t const pwhash_prefix_size = pwhash_prefix.size();
 #endif
 
+void SensitiveData::reallyClearContent(void* data, size_t size) noexcept
+{
+#ifdef HAVE_LIBSODIUM
+  sodium_memzero(data, size);
+#elif defined(HAVE_EXPLICIT_BZERO)
+  explicit_bzero(data, size);
+#elif defined(HAVE_EXPLICIT_MEMSET)
+  explicit_memset(data, 0, size);
+#elif defined(HAVE_GNUTLS_MEMSET)
+  gnutls_memset(data, 0, size);
+#else
+  /* shamelessly taken from Dovecot's src/lib/safe-memset.c */
+  if (size == 0) {
+    return;
+  }
+
+  volatile unsigned int volatile_zero_idx = 0;
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast): sorry!
+  volatile unsigned char* p = reinterpret_cast<volatile unsigned char*>(data);
+  do {
+    memset(data, 0, size);
+  } while (p[volatile_zero_idx] != 0);
+#endif
+}
+
 SensitiveData::SensitiveData(std::string&& data) :
   d_data(std::move(data))
 {
+  // linters are complaining that we are calling data() and capacity() on a moved-from object,
+  // so clear the object first so they shut up
   data.clear();
+#ifdef HAVE_LIBSODIUM
+  // let's be nice and try to zero out the SSO buffer, that cannot be moved
+  reallyClearContent(data.data(), data.capacity());
+#endif
 #ifdef HAVE_LIBSODIUM
   sodium_mlock(d_data.data(), d_data.size());
 #endif
@@ -88,6 +119,9 @@ SensitiveData::~SensitiveData()
 void SensitiveData::clear()
 {
 #ifdef HAVE_LIBSODIUM
+  // let's be nice and try to zero out the SSO buffer (be careful, sodium_munlock will zero out the current size
+  // which might be zero if the object was moved)
+  reallyClearContent(d_data.data(), d_data.capacity());
   sodium_munlock(d_data.data(), d_data.size());
 #endif
   d_data.clear();

pdns/credentials.hh

@@ -45,6 +45,8 @@ public:
     return d_data;
   }
 
+  static void reallyClearContent(void* data, size_t size) noexcept;
+
 private:
   std::string d_data;
 };

pdns/dnsdistdist/dnsdist-configuration-yaml.cc

@@ -458,7 +458,14 @@ static std::shared_ptr<DownstreamState> createBackendFromConfiguration(const Con
   backendConfig.d_numberOfSockets = config.sockets;
   backendConfig.d_qpsLimit = config.queries_per_second;
   backendConfig.order = config.order;
-  backendConfig.d_weight = config.weight;
+  if (config.weight < 1 || config.weight > std::numeric_limits<decltype(backendConfig.d_weight)>::max()) {
+    SLOG(warnlog("Ignoring invalid weight on backend %s", std::string(config.address)),
+         context.logger->info(Logr::Warning, "Ignoring invalid weight on backend", "backend.address", Logging::Loggable(config.address)));
+  }
+  else {
+    backendConfig.d_weight = static_cast<decltype(backendConfig.d_weight)>(config.weight);
+  }
+
   backendConfig.d_maxInFlightQueriesPerConn = config.max_in_flight;
   backendConfig.d_maxUDPOutstanding = config.max_udp_outstanding;
   backendConfig.d_tcpConcurrentConnectionsLimit = config.max_concurrent_tcp_connections;