From 77a986318e9f79a09e12e44d9985ad68673e3dd6 Mon Sep 17 00:00:00 2001
From: Daniel Lublin <daniel@lublin.se>
Date: Thu, 11 Nov 2021 14:07:05 +0100
Subject: [PATCH] Add MailboxPairViewModel that decodes Mailbox QR code

---
 .../briarproject/briar/android/AppModule.java |  2 +
 .../briar/android/mailbox/MailboxModule.java  | 19 ++++
 .../android/mailbox/MailboxPairViewModel.java | 95 +++++++++++++++++++
 3 files changed, 116 insertions(+)
 create mode 100644 briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxModule.java
 create mode 100644 briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxPairViewModel.java

diff --git a/briar-android/src/main/java/org/briarproject/briar/android/AppModule.java b/briar-android/src/main/java/org/briarproject/briar/android/AppModule.java
index a5b6299d0..1d37010ef 100644
--- a/briar-android/src/main/java/org/briarproject/briar/android/AppModule.java
+++ b/briar-android/src/main/java/org/briarproject/briar/android/AppModule.java
@@ -43,6 +43,7 @@ import org.briarproject.briar.android.hotspot.HotspotModule;
 import org.briarproject.briar.android.introduction.IntroductionModule;
 import org.briarproject.briar.android.logging.LoggingModule;
 import org.briarproject.briar.android.login.LoginModule;
+import org.briarproject.briar.android.mailbox.MailboxModule;
 import org.briarproject.briar.android.navdrawer.NavDrawerModule;
 import org.briarproject.briar.android.privategroup.conversation.GroupConversationModule;
 import org.briarproject.briar.android.privategroup.list.GroupListModule;
@@ -103,6 +104,7 @@ import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 		SharingModule.class,
 		HotspotModule.class,
 		TransferDataModule.class,
+		MailboxModule.class,
 })
 public class AppModule {
 
diff --git a/briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxModule.java b/briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxModule.java
new file mode 100644
index 000000000..196e4e151
--- /dev/null
+++ b/briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxModule.java
@@ -0,0 +1,19 @@
+package org.briarproject.briar.android.mailbox;
+
+import org.briarproject.briar.android.viewmodel.ViewModelKey;
+
+import androidx.lifecycle.ViewModel;
+import dagger.Binds;
+import dagger.Module;
+import dagger.multibindings.IntoMap;
+
+@Module
+public interface MailboxModule {
+
+	@Binds
+	@IntoMap
+	@ViewModelKey(MailboxPairViewModel.class)
+	ViewModel bindMailboxViewModel(
+			MailboxPairViewModel mailboxPairViewModel);
+
+}
diff --git a/briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxPairViewModel.java b/briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxPairViewModel.java
new file mode 100644
index 000000000..1c6023997
--- /dev/null
+++ b/briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxPairViewModel.java
@@ -0,0 +1,95 @@
+package org.briarproject.briar.android.mailbox;
+
+import android.app.Application;
+
+import com.google.zxing.Result;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.db.DatabaseExecutor;
+import org.briarproject.bramble.api.db.TransactionManager;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.util.StringUtils;
+import org.briarproject.briar.android.qrcode.QrCodeDecoder;
+import org.briarproject.briar.android.viewmodel.DbViewModel;
+
+import java.nio.charset.Charset;
+import java.util.Arrays;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+
+import androidx.annotation.Nullable;
+import androidx.annotation.UiThread;
+
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Logger.getLogger;
+
+@UiThread
+@NotNullByDefault
+class MailboxPairViewModel extends DbViewModel
+		implements QrCodeDecoder.ResultCallback {
+	private static final Logger LOG =
+			getLogger(MailboxPairViewModel.class.getName());
+
+	private static final int VERSION_REQUIRED = 32;
+
+	@SuppressWarnings("CharsetObjectCanBeUsed") // Requires minSdkVersion >= 19
+	private static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
+
+	private final CryptoComponent crypto;
+	private final QrCodeDecoder qrCodeDecoder;
+
+	@Nullable
+	private String onionAddress = null;
+	@Nullable
+	private String setupToken = null;
+
+	@Inject
+	MailboxPairViewModel(
+			Application app,
+			@DatabaseExecutor Executor dbExecutor,
+			LifecycleManager lifecycleManager,
+			TransactionManager db,
+			AndroidExecutor androidExecutor,
+			@IoExecutor Executor ioExecutor,
+			CryptoComponent crypto) {
+		super(app, dbExecutor, lifecycleManager, db, androidExecutor);
+		this.crypto = crypto;
+		qrCodeDecoder = new QrCodeDecoder(androidExecutor, ioExecutor, this);
+	}
+
+	@Override
+	public void onQrCodeDecoded(Result result) {
+		LOG.info("Got result from decoder");
+		byte[] bytes = result.getText().getBytes(ISO_8859_1);
+
+		if (LOG.isLoggable(INFO))
+			LOG.info("QR code length in bytes: " + bytes.length);
+		if (bytes.length != 65) {
+			LOG.info("QR code has wrong length");
+			return;
+		}
+
+		if (LOG.isLoggable(INFO))
+			LOG.info("QR code version: " + bytes[0]);
+		if (bytes[0] != VERSION_REQUIRED) {
+			LOG.info("QR code has wrong version");
+			return;
+		}
+
+		byte[] onionPubKey = Arrays.copyOfRange(bytes, 1, 33);
+		onionAddress = crypto.encodeOnionAddress(onionPubKey);
+		setupToken = StringUtils.toHexString(Arrays.copyOfRange(bytes, 33, 65))
+				.toLowerCase();
+		LOG.info("QR code is valid");
+	}
+
+	QrCodeDecoder getQrCodeDecoder() {
+		return qrCodeDecoder;
+	}
+
+}