From ec77d99c406d79b05384989baeabec557717b26b Mon Sep 17 00:00:00 2001
From: Frank Lichtenheld <frank@lichtenheld.com>
Date: Tue, 21 Jan 2025 17:53:09 +0100
Subject: [PATCH] Replace usages of _snwprintf

Avoid
warning C4996: '_snwprintf': This function or variable may be unsafe

Also makes the code generally simpler.

Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
---
 access.c           | 11 +++--------
 openvpn.c          | 16 ++++++++--------
 plap/plap_common.c | 19 ++++++++++---------
 proxy.c            |  4 ++--
 registry.c         |  3 +--
 5 files changed, 24 insertions(+), 29 deletions(-)

diff --git a/access.c b/access.c
index 103425e..de3e84e 100644
--- a/access.c
+++ b/access.c
@@ -127,12 +127,8 @@ AddUserToGroup(const WCHAR *group)
     if (GetSystemDirectory(syspath, size))
     {
         syspath[size - 1] = L'\0';
-        size = _countof(cmd);
-        _snwprintf(cmd, size, L"%ls\\%ls", syspath, L"cmd.exe");
-        cmd[size - 1] = L'\0';
-        size = _countof(netcmd);
-        _snwprintf(netcmd, size, L"%ls\\%ls", syspath, L"net.exe");
-        netcmd[size - 1] = L'\0';
+        _snwprintf_s(cmd, _countof(cmd), _TRUNCATE, L"%ls\\%ls", syspath, L"cmd.exe");
+        _snwprintf_s(netcmd, _countof(netcmd), _TRUNCATE, L"%ls\\%ls", syspath, L"net.exe");
     }
     size = (wcslen(fmt) + wcslen(username) + 2 * wcslen(group) + 2 * wcslen(netcmd) + 1);
     if ((params = malloc(size * sizeof(WCHAR))) == NULL)
@@ -140,8 +136,7 @@ AddUserToGroup(const WCHAR *group)
         return retval;
     }
 
-    _snwprintf(params, size, fmt, netcmd, group, netcmd, group, username);
-    params[size - 1] = L'\0';
+    _snwprintf_s(params, size, _TRUNCATE, fmt, netcmd, group, netcmd, group, username);
 
     status = RunAsAdmin(cmd, params);
     if (status == 0)
diff --git a/openvpn.c b/openvpn.c
index cec8d3c..1e7a1dd 100644
--- a/openvpn.c
+++ b/openvpn.c
@@ -1970,8 +1970,8 @@ HandleServiceIO(DWORD err, DWORD bytes, LPOVERLAPPED lpo)
     }
     if (err)
     {
-        _snwprintf(s->readbuf, len, L"0x%08x\nInteractive Service disconnected\n", err);
-        s->readbuf[len - 1] = L'\0';
+        _snwprintf_s(
+            s->readbuf, len, _TRUNCATE, L"0x%08x\nInteractive Service disconnected\n", err);
         SetEvent(s->hEvent);
         return;
     }
@@ -2133,12 +2133,12 @@ OnProcess(connection_t *c, UNUSED char *msg)
         return;
     }
 
-    _snwprintf(tmp,
-               _countof(tmp),
-               L"OpenVPN terminated with exit code %lu. "
-               L"See the log file for details",
-               err);
-    tmp[_countof(tmp) - 1] = L'\0';
+    _snwprintf_s(tmp,
+                 _countof(tmp),
+                 _TRUNCATE,
+                 L"OpenVPN terminated with exit code %lu. "
+                 L"See the log file for details",
+                 err);
     WriteStatusLog(c, L"OpenVPN GUI> ", tmp, false);
 
     OnStop(c, NULL);
diff --git a/plap/plap_common.c b/plap/plap_common.c
index f42f06d..854ef16 100644
--- a/plap/plap_common.c
+++ b/plap/plap_common.c
@@ -70,15 +70,16 @@ x_dmsg(const char *file, const char *func, const wchar_t *fmt, ...)
     wchar_t date[30];
     time_t log_time = time(NULL);
     struct tm *time_struct = localtime(&log_time);
-    _snwprintf(date,
-               _countof(date),
-               L"%d-%.2d-%.2d %.2d:%.2d:%.2d",
-               time_struct->tm_year + 1900,
-               time_struct->tm_mon + 1,
-               time_struct->tm_mday,
-               time_struct->tm_hour,
-               time_struct->tm_min,
-               time_struct->tm_sec);
+    _snwprintf_s(date,
+                 _countof(date),
+                 _TRUNCATE,
+                 L"%d-%.2d-%.2d %.2d:%.2d:%.2d",
+                 time_struct->tm_year + 1900,
+                 time_struct->tm_mon + 1,
+                 time_struct->tm_mday,
+                 time_struct->tm_hour,
+                 time_struct->tm_min,
+                 time_struct->tm_sec);
 
     EnterCriticalSection(&log_write);
 
diff --git a/proxy.c b/proxy.c
index 255c5f6..0e56cb7 100644
--- a/proxy.c
+++ b/proxy.c
@@ -462,11 +462,11 @@ QueryWindowsProxySettings(const url_scheme scheme, LPCSTR host)
             NULL, WINHTTP_ACCESS_TYPE_NO_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
         if (session)
         {
-            int size = _snwprintf(NULL, 0, L"%ls://%hs", UrlSchemeStr(scheme), host) + 1;
+            int size = _scwprintf(L"%ls://%hs", UrlSchemeStr(scheme), host) + 1;
             LPWSTR url = malloc(size * sizeof(WCHAR));
             if (url)
             {
-                _snwprintf(url, size, L"%ls://%hs", UrlSchemeStr(scheme), host);
+                _snwprintf_s(url, size, _TRUNCATE, L"%ls://%hs", UrlSchemeStr(scheme), host);
 
                 LPWSTR old_proxy = proxy;
                 WINHTTP_PROXY_INFO proxy_info;
diff --git a/registry.c b/registry.c
index eccd2c2..d1238ca 100644
--- a/registry.c
+++ b/registry.c
@@ -556,8 +556,7 @@ OpenConfigRegistryKey(const WCHAR *config_name, HKEY *regkey, BOOL create)
         return 0;
     }
 
-    _snwprintf(name, count, fmt, config_name);
-    name[count - 1] = L'\0';
+    _snwprintf_s(name, count, _TRUNCATE, fmt, config_name);
 
     if (!create)
     {