Fix SSLHandshake Exception by using bypass

CHANGELOG.md

@@ -21,6 +21,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 - We added two new fields to track the creation and most recent modification date and time for each entry. [koppor#130](https://github.com/koppor/jabref/issues/130)
 - We added a feature that allows the user to copy highlighted text in the preview window. [#6962](https://github.com/JabRef/jabref/issues/6962)
 - We added a feature that allows you to create new BibEntry via paste arxivId [#2292](https://github.com/JabRef/jabref/issues/2292)
+- We added a feature that allows the user to choose whether to trust the target site when unable to find a valid certification path from the file download site. [#7616](https://github.com/JabRef/jabref/issues/7616)
 
 ### Changed
 

src/main/java/org/jabref/gui/fieldeditors/LinkedFileViewModel.java

@@ -10,6 +10,9 @@
 import java.util.Optional;
 import java.util.function.BiPredicate;
 
+import javax.net.ssl.HostnameVerifier;
+import javax.net.ssl.HttpsURLConnection;
+import javax.net.ssl.SSLSocketFactory;
 import javax.xml.transform.TransformerException;
 
 import javafx.beans.Observable;
@@ -425,6 +428,10 @@ public void download() {
  }
 
  URLDownload urlDownload = new URLDownload(linkedFile.getLink());
+ if (!checkSSLHandshake(urlDownload)) {
+ return;
+ }
+
  BackgroundTask<Path> downloadTask = prepareDownloadTask(targetDirectory.get(), urlDownload);
  downloadTask.onSuccess(destination -> {
  LinkedFile newLinkedFile = LinkedFilesEditorViewModel.fromFile(destination, databaseContext.getFileDirectories(filePreferences), externalFileTypes);
@@ -463,7 +470,28 @@ public void download() {
  }
  }
 
+ public boolean checkSSLHandshake(URLDownload urlDownload) {
+ try {
+ urlDownload.canBeReached();
+ } catch (kong.unirest.UnirestException ex) {
+ if (ex.getCause() instanceof javax.net.ssl.SSLHandshakeException) {
+ if (dialogService.showConfirmationDialogAndWait(Localization.lang("Download file"),
+ Localization.lang("Unable to find valid certification path to requested target(%0), download anyway?",
+ urlDownload.getSource().toString()))) {
+ URLDownload.bypassSSLVerification();
+ return true;
+ } else {
+ dialogService.notify(Localization.lang("Download operation canceled."));
+ }
+ }
+ return false;
+ }
+ return true;
+ }
+
  public BackgroundTask<Path> prepareDownloadTask(Path targetDirectory, URLDownload urlDownload) {
+ SSLSocketFactory defaultSSLSocketFactory = HttpsURLConnection.getDefaultSSLSocketFactory();
+ HostnameVerifier defaultHostnameVerifier = HttpsURLConnection.getDefaultHostnameVerifier();
  BackgroundTask<Path> downloadTask = BackgroundTask
  .wrap(() -> {
  Optional<ExternalFileType> suggestedType = inferFileType(urlDownload);
@@ -476,6 +504,7 @@ public BackgroundTask<Path> prepareDownloadTask(Path targetDirectory, URLDownloa
  return targetDirectory.resolve(fulltextDir).resolve(suggestedName);
  })
  .then(destination -> new FileDownloadTask(urlDownload.getSource(), destination))
+ .onFinished(() -> URLDownload.setSSLVerification(defaultSSLSocketFactory, defaultHostnameVerifier))
  .onFailure(exception -> dialogService.showErrorDialogAndWait("Download failed", exception));
  return downloadTask;
  }

src/main/java/org/jabref/logic/net/URLDownload.java

@@ -36,6 +36,7 @@
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.HttpsURLConnection;
 import javax.net.ssl.SSLContext;
+import javax.net.ssl.SSLSocketFactory;
 import javax.net.ssl.TrustManager;
 import javax.net.ssl.X509TrustManager;
 
@@ -132,6 +133,20 @@ public X509Certificate[] getAcceptedIssuers() {
  }
  }
 
+ /**
+ *
+ * @param socketFactory trust manager
+ * @param verifier host verifier
+ */
+ public static void setSSLVerification(SSLSocketFactory socketFactory, HostnameVerifier verifier) {
+ try {
+ HttpsURLConnection.setDefaultSSLSocketFactory(socketFactory);
+ HttpsURLConnection.setDefaultHostnameVerifier(verifier);
+ } catch (Exception e) {
+ LOGGER.error("A problem occurred when reset SSL verification", e);
+ }
+ }
+
  public URL getSource() {
  return source;
  }

src/main/resources/l10n/JabRef_en.properties

@@ -2292,3 +2292,6 @@ Import\ settings=Import settings
 Custom\ DOI\ URI=Custom DOI URI
 Customization=Customization
 Use\ custom\ DOI\ base\ URI\ for\ article\ access=Use custom DOI base URI for article access
+
+Unable\ to\ find\ valid\ certification\ path\ to\ requested\ target(%0),\ download\ anyway?=Unable to find valid certification path to requested target(%0), download anyway?
+Download\ operation\ canceled.=Download operation canceled.