Added saving S/MIME public keys

app/src/main/java/eu/faircode/email/AdapterCertificate.java

@@ -36,17 +36,25 @@ import android.widget.TextView;
 import androidx.annotation.NonNull;
 import androidx.appcompat.widget.PopupMenu;
 import androidx.fragment.app.Fragment;
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleObserver;
 import androidx.lifecycle.LifecycleOwner;
+import androidx.lifecycle.OnLifecycleEvent;
 import androidx.recyclerview.widget.DiffUtil;
 import androidx.recyclerview.widget.ListUpdateCallback;
 import androidx.recyclerview.widget.RecyclerView;
 
+import java.io.File;
+import java.io.IOException;
+import java.security.cert.CertificateException;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.List;
 
 public class AdapterCertificate extends RecyclerView.Adapter<AdapterCertificate.ViewHolder> {
+    private Fragment parentFragment;
+
     private Context context;
     private LifecycleOwner owner;
     private LayoutInflater inflater;
@@ -93,18 +101,62 @@ public class AdapterCertificate extends RecyclerView.Adapter<AdapterCertificate.
             ss.setSpan(new RelativeSizeSpan(0.9f), 0, ss.length(), 0);
             popupMenu.getMenu().add(Menu.NONE, 0, 0, ss).setEnabled(false);
 
-            popupMenu.getMenu().add(Menu.NONE, R.string.title_delete, 1, R.string.title_delete);
+            popupMenu.getMenu().add(Menu.NONE, R.string.title_save, 1, R.string.title_save);
+            popupMenu.getMenu().add(Menu.NONE, R.string.title_delete, 2, R.string.title_delete);
 
             popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                 @Override
                 public boolean onMenuItemClick(MenuItem item) {
-                    if (item.getItemId() == R.string.title_delete) {
+                    int id = item.getItemId();
+                    if (id == R.string.title_save) {
+                        onActionSave();
+                        return true;
+                    } else if (id == R.string.title_delete) {
                         onActionDelete();
                         return true;
                     }
                     return false;
                 }
 
+                private void onActionSave() {
+                    Bundle args = new Bundle();
+                    args.putLong("id", certificate.id);
+
+                    new SimpleTask<File>() {
+                        @Override
+                        protected File onExecute(Context context, Bundle args) throws CertificateException, IOException {
+                            long id = args.getLong("id");
+
+                            DB db = DB.getInstance(context);
+                            EntityCertificate certificate = db.certificate().getCertificate(id);
+                            if (certificate == null)
+                                return null;
+
+                            File dir = new File(context.getCacheDir(), "shared");
+                            if (!dir.exists())
+                                dir.mkdir();
+
+                            String name = Helper.sanitizeFilename(certificate.email);
+                            File file = new File(dir, name + ".pem");
+                            Helper.writeText(file, certificate.getPem());
+
+                            return file;
+                        }
+
+                        @Override
+                        protected void onExecuted(Bundle args, File file) {
+                            if (file == null)
+                                return;
+                            Helper.share(context, file, "application/*", file.getName());
+                        }
+
+                        @Override
+                        protected void onException(Bundle args, Throwable ex) {
+                            Log.unexpectedError(parentFragment.getParentFragmentManager(), ex);
+                        }
+                    }.execute(context, owner, args, "certificate:save");
+                }
+
                 private void onActionDelete() {
                     Bundle args = new Bundle();
                     args.putLong("id", certificate.id);
@@ -122,7 +174,7 @@ public class AdapterCertificate extends RecyclerView.Adapter<AdapterCertificate.
 
                         @Override
                         protected void onException(Bundle args, Throwable ex) {
-                            // TODO: report error
+                            Log.unexpectedError(parentFragment.getParentFragmentManager(), ex);
                         }
                     }.execute(context, owner, args, "certificate:delete");
                 }
@@ -159,6 +211,15 @@ public class AdapterCertificate extends RecyclerView.Adapter<AdapterCertificate.
         this.TF = Helper.getDateTimeInstance(context, SimpleDateFormat.SHORT, SimpleDateFormat.SHORT);
 
         setHasStableIds(true);
+
+        owner.getLifecycle().addObserver(new LifecycleObserver() {
+            @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
+            public void onDestroyed() {
+                Log.d(AdapterCertificate.this + " parent destroyed");
+                AdapterCertificate.this.parentFragment = null;
+                owner.getLifecycle().removeObserver(this);
+            }
+        });
     }
 
     public void set(@NonNull List<EntityCertificate> certificates) {

app/src/main/java/eu/faircode/email/DaoCertificate.java

@@ -35,6 +35,10 @@ public interface DaoCertificate {
             " ORDER BY intermediate, email, subject")
     LiveData<List<EntityCertificate>> liveCertificates();
 
+    @Query("SELECT * FROM certificate" +
+            " WHERE id = :id")
+    EntityCertificate getCertificate(long id);
+
     @Query("SELECT * FROM certificate" +
             " WHERE fingerprint = :fingerprint" +
             " AND email = :email COLLATE NOCASE")

app/src/main/java/eu/faircode/email/EntityCertificate.java

@@ -37,10 +37,13 @@ import org.bouncycastle.asn1.x509.Extension;
 import org.bouncycastle.asn1.x509.GeneralName;
 import org.bouncycastle.asn1.x509.SubjectKeyIdentifier;
 import org.bouncycastle.cert.jcajce.JcaX509CertificateHolder;
+import org.bouncycastle.openssl.jcajce.JcaPEMWriter;
 import org.json.JSONException;
 import org.json.JSONObject;
 
 import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.StringWriter;
 import java.security.NoSuchAlgorithmException;
 import java.security.cert.CertificateEncodingException;
 import java.security.cert.CertificateException;
@@ -111,6 +114,15 @@ public class EntityCertificate {
                 .generateCertificate(new ByteArrayInputStream(encoded));
     }
 
+    String getPem() throws CertificateException, IOException {
+        StringWriter writer = new StringWriter();
+        JcaPEMWriter pemWriter = new JcaPEMWriter(writer);
+        pemWriter.writeObject(getCertificate());
+        pemWriter.flush();
+        pemWriter.close();
+        return writer.toString();
+    }
+
     boolean isExpired() {
         return isExpired(null);
     }