attempt to parse Link header from https url scanned from welcome screen

src/conversations/java/eu/siacs/conversations/ui/WelcomeActivity.java

@@ -106,7 +106,8 @@ public class WelcomeActivity extends XmppActivity implements XmppConnectionServi
     }
 
     @Override
-    public void onNewIntent(Intent intent) {
+    public void onNewIntent(final Intent intent) {
+        super.onNewIntent(intent);
         if (intent != null) {
             setIntent(intent);
         }

src/main/java/eu/siacs/conversations/ui/UriHandlerActivity.java

@@ -7,24 +7,39 @@ import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
+import android.util.Log;
+import android.view.View;
 import android.widget.Toast;
 
+import androidx.annotation.StringRes;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.content.ContextCompat;
+import androidx.databinding.DataBindingUtil;
 
 import com.google.common.base.Strings;
 
+import org.jetbrains.annotations.NotNull;
+
+import java.io.IOException;
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
+import eu.siacs.conversations.databinding.ActivityUriHandlerBinding;
+import eu.siacs.conversations.http.HttpConnectionManager;
 import eu.siacs.conversations.persistance.DatabaseBackend;
 import eu.siacs.conversations.services.QuickConversationsService;
 import eu.siacs.conversations.utils.ProvisioningUtils;
 import eu.siacs.conversations.utils.SignupUtils;
 import eu.siacs.conversations.utils.XmppUri;
 import eu.siacs.conversations.xmpp.Jid;
+import okhttp3.Call;
+import okhttp3.Callback;
+import okhttp3.HttpUrl;
+import okhttp3.Request;
+import okhttp3.Response;
 
 public class UriHandlerActivity extends AppCompatActivity {
 
@@ -34,7 +49,9 @@ public class UriHandlerActivity extends AppCompatActivity {
     private static final int REQUEST_CAMERA_PERMISSIONS_TO_SCAN = 0x6789;
     private static final int REQUEST_CAMERA_PERMISSIONS_TO_SCAN_AND_PROVISION = 0x6790;
     private static final Pattern V_CARD_XMPP_PATTERN = Pattern.compile("\nIMPP([^:]*):(xmpp:.+)\n");
-    private boolean handled = false;
+    private static final Pattern LINK_HEADER_PATTERN = Pattern.compile("<(.*?)>");
+    private ActivityUriHandlerBinding binding;
+    private Call call;
 
     public static void scan(final Activity activity) {
         scan(activity, false);
@@ -77,9 +94,7 @@ public class UriHandlerActivity extends AppCompatActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        this.handled = savedInstanceState != null && savedInstanceState.getBoolean("handled", false);
+        this.binding = DataBindingUtil.setContentView(this, R.layout.activity_uri_handler);
-        getLayoutInflater().inflate(R.layout.toolbar, findViewById(android.R.id.content));
-        setSupportActionBar(findViewById(R.id.toolbar));
     }
 
     @Override
@@ -88,23 +103,17 @@ public class UriHandlerActivity extends AppCompatActivity {
         handleIntent(getIntent());
     }
 
-    @Override
-    public void onSaveInstanceState(Bundle savedInstanceState) {
-        savedInstanceState.putBoolean("handled", this.handled);
-        super.onSaveInstanceState(savedInstanceState);
-    }
-
     @Override
     public void onNewIntent(final Intent intent) {
         super.onNewIntent(intent);
         handleIntent(intent);
     }
 
-    private void handleUri(Uri uri) {
+    private boolean handleUri(final Uri uri) {
-        handleUri(uri, false);
+        return handleUri(uri, false);
     }
 
-    private void handleUri(Uri uri, final boolean scanned) {
+    private boolean handleUri(final Uri uri, final boolean scanned) {
         final Intent intent;
         final XmppUri xmppUri = new XmppUri(uri);
         final List<Jid> accounts = DatabaseBackend.getInstance(this).getAccountJids(true);
@@ -114,19 +123,22 @@ public class UriHandlerActivity extends AppCompatActivity {
             final Jid jid = xmppUri.getJid();
             if (xmppUri.isAction(XmppUri.ACTION_REGISTER)) {
                 if (jid.getEscapedLocal() != null && accounts.contains(jid.asBareJid())) {
-                    Toast.makeText(this, R.string.account_already_exists, Toast.LENGTH_LONG).show();
+                    showError(R.string.account_already_exists);
-                    return;
+                    return false;
                 }
                 intent = SignupUtils.getTokenRegistrationIntent(this, jid, preAuth);
                 startActivity(intent);
-                return;
+                return true;
             }
             if (accounts.size() == 0 && xmppUri.isAction(XmppUri.ACTION_ROSTER) && "y".equals(xmppUri.getParameter(XmppUri.PARAMETER_IBR))) {
                 intent = SignupUtils.getTokenRegistrationIntent(this, jid.getDomain(), preAuth);
                 intent.putExtra(StartConversationActivity.EXTRA_INVITE_URI, xmppUri.toString());
                 startActivity(intent);
-                return;
+                return true;
             }
+        } else if (xmppUri.isAction(XmppUri.ACTION_REGISTER)) {
+            showError(R.string.account_registrations_are_not_supported);
+            return false;
         }
 
         if (accounts.size() == 0) {
@@ -134,15 +146,14 @@ public class UriHandlerActivity extends AppCompatActivity {
                 intent = SignupUtils.getSignUpIntent(this);
                 intent.putExtra(StartConversationActivity.EXTRA_INVITE_URI, xmppUri.toString());
                 startActivity(intent);
+                return true;
             } else {
-                Toast.makeText(this, R.string.invalid_jid, Toast.LENGTH_SHORT).show();
+                showError(R.string.invalid_jid);
+                return false;
             }
-
-            return;
         }
 
         if (xmppUri.isAction(XmppUri.ACTION_MESSAGE)) {
-
             final Jid jid = xmppUri.getJid();
             final String body = xmppUri.getBody();
 
@@ -177,11 +188,57 @@ public class UriHandlerActivity extends AppCompatActivity {
             intent.putExtra("scanned", scanned);
             intent.setData(uri);
         } else {
-            Toast.makeText(this, R.string.invalid_jid, Toast.LENGTH_SHORT).show();
+            showError(R.string.invalid_jid);
-            return;
+            return false;
         }
-
         startActivity(intent);
+        return true;
+    }
+
+    private void checkForLinkHeader(final HttpUrl url) {
+        Log.d(Config.LOGTAG, "checking for link header on " + url);
+        this.call = HttpConnectionManager.OK_HTTP_CLIENT.newCall(new Request.Builder()
+                .url(url)
+                .head()
+                .build());
+        this.call.enqueue(new Callback() {
+            @Override
+            public void onFailure(@NotNull Call call, @NotNull IOException e) {
+                Log.d(Config.LOGTAG, "unable to check HTTP url", e);
+                showError(R.string.no_xmpp_adddress_found);
+            }
+
+            @Override
+            public void onResponse(@NotNull Call call, @NotNull Response response) {
+                if (response.isSuccessful()) {
+                    final String linkHeader = response.header("Link");
+                    if (linkHeader != null && processLinkHeader(linkHeader)) {
+                        return;
+                    }
+                }
+                showError(R.string.no_xmpp_adddress_found);
+            }
+        });
+
+    }
+
+    private boolean processLinkHeader(final String header) {
+        final Matcher matcher = LINK_HEADER_PATTERN.matcher(header);
+        if (matcher.find()) {
+            final String group = matcher.group();
+            final String link = group.substring(1, group.length() - 1);
+            if (handleUri(Uri.parse(link))) {
+                finish();
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private void showError(@StringRes int error) {
+        this.binding.progress.setVisibility(View.INVISIBLE);
+        this.binding.error.setText(error);
+        this.binding.error.setVisibility(View.VISIBLE);
     }
 
     private static Class<?> findShareViaAccountClass() {
@@ -192,29 +249,33 @@ public class UriHandlerActivity extends AppCompatActivity {
         }
     }
 
-    private void handleIntent(Intent data) {
+    private void handleIntent(final Intent data) {
-        if (handled) {
+        final String action = data == null ? null : data.getAction();
+        if (action == null) {
             return;
         }
-        if (data == null || data.getAction() == null) {
+        switch (action) {
-            finish();
+            case Intent.ACTION_MAIN:
-            return;
+                binding.progress.setVisibility(call != null && !call.isCanceled() ? View.VISIBLE : View.INVISIBLE);
-        }
+                break;
-
-        handled = true;
-
-        switch (data.getAction()) {
             case Intent.ACTION_VIEW:
             case Intent.ACTION_SENDTO:
-                handleUri(data.getData());
+                if (handleUri(data.getData())) {
+                    finish();
+                }
                 break;
             case ACTION_SCAN_QR_CODE:
-                Intent intent = new Intent(this, ScanActivity.class);
+                Log.d(Config.LOGTAG, "scan. allow=" + allowProvisioning());
-                startActivityForResult(intent, REQUEST_SCAN_QR_CODE);
+                setIntent(createMainIntent());
-                return;
+                startActivityForResult(new Intent(this, ScanActivity.class), REQUEST_SCAN_QR_CODE);
+                break;
         }
+    }
 
-        finish();
+    private Intent createMainIntent() {
+        final Intent intent = new Intent(Intent.ACTION_MAIN);
+        intent.putExtra(EXTRA_ALLOW_PROVISIONING, allowProvisioning());
+        return intent;
     }
 
     private boolean allowProvisioning() {
@@ -226,6 +287,7 @@ public class UriHandlerActivity extends AppCompatActivity {
     public void onActivityResult(final int requestCode, final int resultCode, final Intent intent) {
         super.onActivityResult(requestCode, requestCode, intent);
         if (requestCode == REQUEST_SCAN_QR_CODE && resultCode == RESULT_OK) {
+            final boolean allowProvisioning = allowProvisioning();
             final String result = intent.getStringExtra(ScanActivity.INTENT_EXTRA_RESULT);
             if (Strings.isNullOrEmpty(result)) {
                 finish();
@@ -234,18 +296,34 @@ public class UriHandlerActivity extends AppCompatActivity {
             if (result.startsWith("BEGIN:VCARD\n")) {
                 final Matcher matcher = V_CARD_XMPP_PATTERN.matcher(result);
                 if (matcher.find()) {
-                    handleUri(Uri.parse(matcher.group(2)), true);
+                    if (handleUri(Uri.parse(matcher.group(2)), true)) {
+                        finish();
+                    }
+                } else {
+                    showError(R.string.no_xmpp_adddress_found);
                 }
-                finish();
                 return;
-            } else if (QuickConversationsService.isConversations() && looksLikeJsonObject(result) && allowProvisioning()) {
+            } else if (QuickConversationsService.isConversations() && looksLikeJsonObject(result) && allowProvisioning) {
                 ProvisioningUtils.provision(this, result);
                 finish();
                 return;
             }
-            handleUri(Uri.parse(result), true);
+            final Uri uri = Uri.parse(result.trim());
+            if (allowProvisioning && "https".equalsIgnoreCase(uri.getScheme()) && !XmppUri.INVITE_DOMAIN.equalsIgnoreCase(uri.getHost())) {
+                final HttpUrl httpUrl = HttpUrl.parse(uri.toString());
+                if (httpUrl != null) {
+                    checkForLinkHeader(httpUrl);
+                } else {
+                    finish();
+                }
+            } else if (handleUri(uri, true)) {
+                finish();
+            } else {
+                setIntent(new Intent(Intent.ACTION_VIEW, uri));
+            }
+        } else {
+            finish();
         }
-        finish();
     }
 
     private static boolean looksLikeJsonObject(final String input) {

src/main/java/eu/siacs/conversations/utils/XmppUri.java

@@ -35,6 +35,8 @@ public class XmppUri {
     private Map<String, String> parameters = Collections.emptyMap();
     private boolean safeSource = true;
 
+    public static final String INVITE_DOMAIN = "conversations.im";
+
     public XmppUri(final String uri) {
         try {
             parse(Uri.parse(uri));
@@ -136,10 +138,10 @@ public class XmppUri {
             return;
         }
         this.uri = uri;
-        String scheme = uri.getScheme();
+        final String scheme = uri.getScheme();
-        String host = uri.getHost();
+        final String host = uri.getHost();
         List<String> segments = uri.getPathSegments();
-        if ("https".equalsIgnoreCase(scheme) && "conversations.im".equalsIgnoreCase(host)) {
+        if ("https".equalsIgnoreCase(scheme) && INVITE_DOMAIN.equalsIgnoreCase(host)) {
             if (segments.size() >= 2 && segments.get(1).contains("@")) {
                 // sample : https://conversations.im/i/foo@bar.com
                 try {

src/main/res/layout/activity_uri_handler.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layout xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <RelativeLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:background="?colorPrimaryDark"
+        android:padding="24dp">
+
+        <ProgressBar
+            android:id="@+id/progress"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_centerInParent="true"
+            android:indeterminate="true"
+            android:indeterminateTint="@color/white" />
+
+        <TextView
+            android:id="@+id/error"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_below="@+id/progress"
+            android:layout_centerHorizontal="true"
+            android:layout_marginTop="16dp"
+            android:gravity="center_horizontal"
+            android:textAppearance="@style/TextAppearance.Conversations.Body2"
+            android:textColor="@color/white87"
+            android:visibility="invisible" />
+
+    </RelativeLayout>
+</layout>

src/main/res/values/strings.xml

@@ -968,5 +968,7 @@
     <string name="backup_started_message">The backup has been started. You’ll get a notification once it has been completed.</string>
     <string name="unable_to_enable_video">Unable to enable video.</string>
     <string name="plain_text_document">Plain text document</string>
+    <string name="account_registrations_are_not_supported">Account registrations are not supported</string>
+    <string name="no_xmpp_adddress_found">No XMPP address found</string>
 
 </resources>