Fix Bluetooth share without breaking others

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/KeychainApplication.java

@@ -40,6 +40,8 @@ import org.sufficientlysecure.keychain.util.PRNGFixes;
 import org.sufficientlysecure.keychain.util.Preferences;
 import org.sufficientlysecure.keychain.util.TlsHelper;
 
+import java.io.File;
+import java.io.FilenameFilter;
 import java.security.Security;
 import java.util.HashMap;
 
@@ -88,6 +90,17 @@ public class KeychainApplication extends Application {
             }
         }
 
+        // Clean up leftover Bluetooth Share files
+        for (File toDelete : this.getExternalCacheDir().listFiles(new FilenameFilter() {
+            @Override
+            public boolean accept(File dir, String filename) {
+                if (filename.matches("^key-[0-9a-fA-F]{8}\\.pgp\\.asc$")) {
+                    return true;
+                }
+                return false;
+            }
+        })) { toDelete.delete(); }
+
         brandGlowEffect(getApplicationContext(),
                 getApplicationContext().getResources().getColor(R.color.primary));
 

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewKeyAdvShareFragment.java

@@ -26,6 +26,7 @@ import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.FileObserver;
 import android.support.v4.app.ActivityCompat;
 import android.support.v4.app.LoaderManager;
 import android.support.v4.content.CursorLoader;
@@ -54,6 +55,9 @@ import org.sufficientlysecure.keychain.ui.util.QrCodeUtils;
 import org.sufficientlysecure.keychain.util.Log;
 import org.sufficientlysecure.keychain.util.NfcHelper;
 
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileWriter;
 import java.io.IOException;
 
 
@@ -175,11 +179,11 @@ public class ViewKeyAdvShareFragment extends LoaderFragment implements
                        boolean toClipboard) {
         try {
             String content;
-            if (fingerprintOnly) {
-                byte[] data = (byte[]) providerHelper.getGenericData(
+            byte[] fingerprintData = (byte[]) providerHelper.getGenericData(
                     KeyRings.buildUnifiedKeyRingUri(dataUri),
                     Keys.FINGERPRINT, ProviderHelper.FIELD_TYPE_BLOB);
-                String fingerprint = KeyFormattingUtils.convertFingerprintToHex(data);
+            if (fingerprintOnly) {
+                String fingerprint = KeyFormattingUtils.convertFingerprintToHex(fingerprintData);
                 if (!toClipboard) {
                     content = Constants.FINGERPRINT_SCHEME + ":" + fingerprint;
                 } else {
@@ -213,13 +217,62 @@ public class ViewKeyAdvShareFragment extends LoaderFragment implements
                 Intent sendIntent = new Intent(Intent.ACTION_SEND);
                 sendIntent.putExtra(Intent.EXTRA_TEXT, content);
                 sendIntent.setType("text/plain");
+
                 String title;
                 if (fingerprintOnly) {
                     title = getResources().getString(R.string.title_share_fingerprint_with);
                 } else {
                     title = getResources().getString(R.string.title_share_key);
                 }
-                startActivity(Intent.createChooser(sendIntent, title));
+                Intent shareChooser = Intent.createChooser(sendIntent, title);
+
+                // Bluetooth Share will convert text/plain sent via EXTRA_TEXT to HTML
+                // Add replacement extra to send a text/plain file instead.
+                try {
+                    final File contentFile = new File(getActivity().getExternalCacheDir(),
+                            "key-" + KeyFormattingUtils.getShortKeyIdAsHexFromFingerprint(fingerprintData, false) +
+                            ".pgp.asc");
+                    FileWriter contentFileWriter = new FileWriter(contentFile, false);
+                    BufferedWriter contentWriter = new BufferedWriter(contentFileWriter);
+                    contentWriter.write(content);
+                    contentWriter.close();
+                    Uri contentUri = Uri.fromFile(contentFile);
+
+                    final Runnable deleteContentFile = new Runnable() {
+                        public void run() {
+                            contentFile.delete();
+                        }
+                    };
+
+                    // delete the file after Bluetooth Share closes the file
+                    FileObserver tempFileObserver = new FileObserver(contentFile.getAbsolutePath(),
+                            FileObserver.CLOSE_NOWRITE) {
+                        @Override
+                        public void onEvent(int event, String path) {
+                            // Hopefully it will only be opened and then closed by the share process once
+                            getContainer().post(deleteContentFile);
+                        }
+                    };
+                    tempFileObserver.startWatching();
+
+                    // If it's not complete in 1m, the file was not used; delete it
+                    getContainer().postDelayed(deleteContentFile, 1 * 60 * 1000);
+
+                    // create replacement extras inside try{}:
+                    // if file creation fails, just don't add the replacements
+                    Bundle replacements = new Bundle();
+                    shareChooser.putExtra(Intent.EXTRA_REPLACEMENT_EXTRAS, replacements);
+
+                    Bundle bluetoothExtra = new Bundle(sendIntent.getExtras());
+                    replacements.putBundle("com.android.bluetooth", bluetoothExtra);
+
+                    bluetoothExtra.putParcelable(Intent.EXTRA_STREAM, contentUri);
+                } catch (IOException e) {
+                    Log.e(Constants.TAG, "error creating temporary Bluetooth key share file!", e);
+                    Notify.create(getActivity(), R.string.error_bluetooth_file, Notify.Style.ERROR).show();
+                }
+
+                startActivity(shareChooser);
             }
         } catch (PgpGeneralException | IOException e) {
             Log.e(Constants.TAG, "error processing key!", e);

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/KeyFormattingUtils.java

@@ -227,6 +227,14 @@ public class KeyFormattingUtils {
         return buf.getLong();
     }
 
+    public static int getShortKeyIdFromFingerprint(byte[] fingerprint) {
+        ByteBuffer buf = ByteBuffer.wrap(fingerprint);
+        // skip first 16 bytes of the fingerprint
+        buf.position(16);
+        // the last four bytes are the short key id (big endian, which is default order in ByteBuffer)
+        return buf.getInt();
+    }
+
     /**
      * Convert key id from long to 64 bit hex string
      * <p/>
@@ -238,16 +246,24 @@ public class KeyFormattingUtils {
      * @return
      */
     public static String convertKeyIdToHex(long keyId) {
+        return convertKeyIdToHex(keyId, true);
+    }
+
+    public static String convertKeyIdToHex(long keyId, boolean header) {
         long upper = keyId >> 32;
         if (upper == 0) {
             // this is a short key id
-            return convertKeyIdToHexShort(keyId);
+            return convertKeyIdToHexShort(keyId, header);
         }
-        return "0x" + convertKeyIdToHex32bit(keyId >> 32) + convertKeyIdToHex32bit(keyId);
+        return header?"0x":"" + convertKeyIdToHex32bit(keyId >> 32) + convertKeyIdToHex32bit(keyId);
     }
 
     public static String convertKeyIdToHexShort(long keyId) {
-        return "0x" + convertKeyIdToHex32bit(keyId);
+        return convertKeyIdToHexShort(keyId, true);
+    }
+
+    public static String convertKeyIdToHexShort(long keyId, boolean header) {
+        return header?"0x":"" + convertKeyIdToHex32bit(keyId);
     }
 
     private static String convertKeyIdToHex32bit(long keyId) {
@@ -258,6 +274,14 @@ public class KeyFormattingUtils {
         return hexString;
     }
 
+    public static String getKeyIdAsHexFromFingerprint(byte[] fingerprint, boolean header) {
+        return convertKeyIdToHex(getKeyIdFromFingerprint(fingerprint), header);
+    }
+
+    public static String getShortKeyIdAsHexFromFingerprint(byte[] fingerprint, boolean header) {
+        return convertKeyIdToHex(getShortKeyIdFromFingerprint(fingerprint), header);
+    }
+
     /**
      * Makes a human-readable version of a key ID, which is usually 64 bits: lower-case, no
      * leading 0x, space-separated quartets (for keys whose length in hex is divisible by 4)

OpenKeychain/src/main/res/values/strings.xml

@@ -1289,5 +1289,6 @@
     <string name="snack_yubi_other">Different key stored on YubiKey!</string>
     <string name="error_nfc">"NFC Error: %s"</string>
     <string name="error_pin_nodefault">Default PIN was rejected!</string>
+    <string name="error_bluetooth_file">Error creating temporary file. Bluetooth sharing will fail.</string>
 
 </resources>