vuln-fix: Temporary File Information Disclosure

This fixes temporary file information disclosure vulnerability due to the use
of the vulnerable `File.createTempFile()` method. The vulnerability is fixed by
using the `Files.createTempFile()` method which sets the correct posix permissions.

Weakness: CWE-377: Insecure Temporary File
Severity: Medium
CVSSS: 5.5
Detection: CodeQL & OpenRewrite (https://public.moderne.io/recipes/org.openrewrite.java.security.SecureTempFileCreation)

Reported-by: Jonathan Leitschuh <Jonathan.Leitschuh@gmail.com>
Signed-off-by: Jonathan Leitschuh <Jonathan.Leitschuh@gmail.com>

Bug-tracker: https://github.com/JLLeitschuh/security-research/issues/18


Co-authored-by: Moderne <team@moderne.io>

maxkey-common/src/main/java/org/maxkey/crypto/cert/NetUtil.java

@@ -31,6 +31,7 @@ import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URL;
 import java.net.URLConnection;
+import java.nio.file.Files;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -140,7 +141,7 @@ public final class NetUtil
 
 		try
 		{
-			tempFile = File.createTempFile("portecle", null);
+			tempFile = Files.createTempFile("portecle",null).toFile();
 			out = new BufferedOutputStream(new FileOutputStream(tempFile));
 			byte[] buf = new byte[2048];
 			int n;