discover file extension in original filename from pgp

1 files changed, 32 insertions, 0 deletions

diff --git a/src/main/java/de/pixart/messenger/utils/MimeUtils.java b/src/main/java/de/pixart/messenger/utils/MimeUtils.java
index bfcf71c6e..bf3b962ab 100644
--- a/src/main/java/de/pixart/messenger/utils/MimeUtils.java
+++ b/src/main/java/de/pixart/messenger/utils/MimeUtils.java
@@ -22,10 +22,13 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
 
+import de.pixart.messenger.entities.Transferable;
+
 /**
  * Utilities for dealing with MIME types.
  * Used to implement java.net.URLConnection and android.webkit.MimeTypeMap.
@@ -529,4 +532,33 @@ public final class MimeUtils {
         }
         return mimeType;
     }
+
+    public static String extractRelevantExtension(URL url) {
+        String path = url.getPath();
+        return extractRelevantExtension(path, true);
+    }
+
+    public static String extractRelevantExtension(final String path) {
+        return extractRelevantExtension(path, false);
+    }
+
+    public static String extractRelevantExtension(final String path, final boolean ignoreCryptoExtension) {
+        if (path == null || path.isEmpty()) {
+            return null;
+        }
+
+        String filename = path.substring(path.lastIndexOf('/') + 1).toLowerCase();
+        int dotPosition = filename.lastIndexOf(".");
+
+        if (dotPosition != -1) {
+            String extension = filename.substring(dotPosition + 1);
+            // we want the real file extension, not the crypto one
+            if (ignoreCryptoExtension && Transferable.VALID_CRYPTO_EXTENSIONS.contains(extension)) {
+                return extractRelevantExtension(filename.substring(0, dotPosition));
+            } else {
+                return extension;
+            }
+        }
+        return null;
+    }
 }