feat: support tor and torsf proxies

app/src/main/java/org/openobservatory/ooniprobe/activity/ProxyActivity.java

@@ -48,9 +48,15 @@ public class ProxyActivity extends AbstractActivity {
      *
      * 1. an empty string means no proxy;
      *
-     * 2. "psiphon://" means that we wanna use psiphon;
+     * 2. "psiphon:///" means that we want to use psiphon;
      *
-     * 3. "socks5://1.2.3.4:5678" or "socks5://[::1]:5678" or "socks5://d.com:5678"
+     * 3. "tor:///" means we want to use tor without any proxy (which is possible
+     * because oonimkall embeds `libtor.a` as a dependency);
+     *
+     * 4. "torsf:///" is like "tor:///" but additionally uses the snowflake
+     * library we also bundle inside of oonimkall;
+     *
+     * 5. "socks5://1.2.3.4:5678" or "socks5://[::1]:5678" or "socks5://d.com:5678"
      * means that we wanna use the given socks5 proxy.
      *
      * Future improvements
@@ -67,8 +73,6 @@ public class ProxyActivity extends AbstractActivity {
      * This implies we can trivially support a vanilla socks5 proxy with username and
      * password by just replacing `psiphon+socks5` with `socks5`.
      *
-     * We also want to support vanilla tor, using `tor://`.
-     *
      * We also want to support vanilla tor with socks5, which is trivially doable
      * using as a scheme the `tor+socks5` scheme.
      *
@@ -93,15 +97,20 @@ public class ProxyActivity extends AbstractActivity {
      * The design and implementation of this class owes to the code contributed
      * by and the suggestion from friendly anonymous users. Thank you!
      */
+
+    // logger is the injected AppLogger instance.
     @Inject
     AppLogger logger;
+
     // TAG is the tag used for logging.
     private final static String TAG = "ProxyActivity";
 
+    // preferenceManager is the injected PreferenceManager instance.
     @Inject
     PreferenceManager preferenceManager;
-    // The following radio group describes the top level choice
-    // in terms of proxying: no proxy, psiphon, or custom.
+
+    // The following radio group describes the top level choice in terms of
+    // proxying: no proxy, psiphon, tor, torsf, or custom.
 
     // proxyRadioGroup is the top-level radio group.
     private RadioGroup proxyRadioGroup;
@@ -112,12 +121,21 @@ public class ProxyActivity extends AbstractActivity {
     // proxyPsiphonRB is the radio button selecting the "psiphon" proxy.
     private RadioButton proxyPsiphonRB;
 
+    // proxyTorRB is the radio button selecting the "tor" proxy.
+    private RadioButton proxyTorRB;
+
+    // proxyTorSfRB is the radio button selecting the "torsf" proxy.
+    private RadioButton proxyTorSfRB;
+
     // proxyCustomRB is the radio button for the "custom" proxy.
     private RadioButton proxyCustomRB;
 
     // The following radio group allows users to choose which specific
     // custom proxy they would like to use. When writing this documentation,
     // only socks5 is available but we will add more options.
+    //
+    // TODO(bassosimone): we need to implement support for HTTP proxies
+    // once https://github.com/ooni/probe-cli/pull/1162 lands.
 
     // customProxyRadioGroup allows you to choose among the different
     // kinds of custom proxies that are available.
@@ -153,6 +171,8 @@ public void onCreate(Bundle savedInstanceState) {
         proxyRadioGroup = findViewById(R.id.proxyRadioGroup);
         proxyNoneRB = findViewById(R.id.proxyNone);
         proxyPsiphonRB = findViewById(R.id.proxyPsiphon);
+        proxyTorRB = findViewById(R.id.proxyTor);
+        proxyTorSfRB = findViewById(R.id.proxyTorSf);
         proxyCustomRB = findViewById(R.id.proxyCustom);
         customProxyRadioGroup = findViewById(R.id.customProxyRadioGroup);
         customProxySOCKS5 = findViewById(R.id.customProxySOCKS5);
@@ -196,6 +216,10 @@ private void configureInitialViewWithSettings(ProxySettings settings) {
             proxyNoneRB.setChecked(true);
         } else if (settings.protocol == ProxyProtocol.PSIPHON) {
             proxyPsiphonRB.setChecked(true);
+        } else if (settings.protocol == ProxyProtocol.TOR) {
+            proxyTorRB.setChecked(true);
+        } else if (settings.protocol == ProxyProtocol.TORSF) {
+            proxyTorSfRB.setChecked(true);
         } else if (settings.protocol == ProxyProtocol.SOCKS5) {
             proxyCustomRB.setChecked(true);
         } else {
@@ -226,6 +250,10 @@ private void configureInitialViewWithSettings(ProxySettings settings) {
                 customProxySetEnabled(false);
             } else if (checkedId == R.id.proxyPsiphon) {
                 customProxySetEnabled(false);
+            } else if (checkedId == R.id.proxyTor) {
+                customProxySetEnabled(false);
+            } else if (checkedId == R.id.proxyTorSf) {
+                customProxySetEnabled(false);
             } else if (checkedId == R.id.proxyCustom) {
                 customProxySetEnabled(true);
                 customProxyRadioGroup.clearCheck();
@@ -364,6 +392,24 @@ public void onBackPressed() {
             return;
         }
 
+        // If the tor proxy is checked then write back the right
+        // proxy configuration for tor and move on.
+        if (proxyTorRB.isChecked()) {
+            settings.protocol = ProxyProtocol.TOR;
+            saveSettings();
+            super.onBackPressed();
+            return;
+        }
+
+        // If the torsf proxy is checked then write back the right
+        // proxy configuration for torsf and move on.
+        if (proxyTorSfRB.isChecked()) {
+            settings.protocol = ProxyProtocol.TORSF;
+            saveSettings();
+            super.onBackPressed();
+            return;
+        }
+
         // validate the hostname for the custom proxy.
         if (!isValidHostnameOrIP(hostname)) {
             customProxyHostname.setError("not a valid hostname or IP");

app/src/main/java/org/openobservatory/ooniprobe/common/ProxyProtocol.java

@@ -4,6 +4,8 @@
 public enum ProxyProtocol {
     NONE("none"),
     PSIPHON("psiphon"),
+    TOR("tor"),
+    TORSF("torsf"),
     SOCKS5("socks5");
 
     private String protocol;

app/src/main/java/org/openobservatory/ooniprobe/common/ProxySettings.java

@@ -13,8 +13,7 @@
  * documentation of proxy activity for the design rationale.
  */
 public class ProxySettings {
-
-    /** scheme is the proxy scheme (e.g., "psiphon", "socks5"). */
+    /** scheme is the proxy scheme (e.g., "psiphon", "tor", "torsf", "socks5"). */
     public ProxyProtocol protocol = ProxyProtocol.NONE;
 
     /** hostname is the hostname for custom proxies. */
@@ -33,10 +32,14 @@ public static ProxySettings newProxySettings(PreferenceManager pm) throws Invali
             settings.protocol = ProxyProtocol.NONE;
         } else if (protocol.equals(ProxyProtocol.PSIPHON.getProtocol())) {
             settings.protocol = ProxyProtocol.PSIPHON;
+        } else if (protocol.equals(ProxyProtocol.TOR.getProtocol())) {
+            settings.protocol = ProxyProtocol.TOR;
+        } else if (protocol.equals(ProxyProtocol.TORSF.getProtocol())) {
+            settings.protocol = ProxyProtocol.TORSF;
         } else if (protocol.equals(ProxyProtocol.SOCKS5.getProtocol())) {
             settings.protocol = ProxyProtocol.SOCKS5;
         } else {
-            // This is where we will extend the code to add support for
+            // This exception indicates that we need to extend the code to support
             // more proxies, e.g., HTTP proxies.
             throw new InvalidProxyURL("unhandled URL scheme");
         }
@@ -72,10 +75,18 @@ private boolean isIPv6(String hostname) {
 
     /** getProxyString returns to you the proxy string you should pass to oonimkall. */
     public String getProxyString() throws URISyntaxException {
-        if (protocol == ProxyProtocol.NONE)
+        if (protocol == ProxyProtocol.NONE) {
             return "";
-        if (protocol == ProxyProtocol.PSIPHON)
-            return "psiphon://";
+        }
+        if (protocol == ProxyProtocol.PSIPHON) {
+            return "psiphon:///";
+        }
+        if (protocol == ProxyProtocol.TOR) {
+            return "tor:///";
+        }
+        if (protocol == ProxyProtocol.TORSF) {
+            return "torsf:///";
+        }
         if (protocol == ProxyProtocol.SOCKS5) {
             // Alright, we now need to construct a new SOCKS5 URL. We are going to defer
             // doing that to the Java standard library (er, the Android stdlib).

app/src/main/res/layout/activity_proxy.xml

@@ -38,6 +38,20 @@
                     android:textColor="@color/color_black"
                     android:text="@string/Settings_Proxy_Psiphon" />
 
+                <RadioButton
+                    android:id="@+id/proxyTor"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:textColor="@color/color_black"
+                    android:text="@string/Settings_Proxy_Tor" />
+
+                <RadioButton
+                    android:id="@+id/proxyTorSf"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:textColor="@color/color_black"
+                    android:text="@string/Settings_Proxy_TorSf" />
+
                 <RadioButton
                     android:id="@+id/proxyCustom"
                     android:layout_width="wrap_content"
@@ -114,4 +128,4 @@
         </LinearLayout>
     </ScrollView>
 
-</androidx.constraintlayout.widget.ConstraintLayout>
+</androidx.constraintlayout.widget.ConstraintLayout>

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

@@ -392,6 +392,8 @@
   <string name="Settings_Proxy_Enabled">Proxy</string>
   <string name="Settings_Proxy_None">None</string>
   <string name="Settings_Proxy_Psiphon">Psiphon</string>
+  <string name="Settings_Proxy_Tor">Tor (vanilla)</string>
+  <string name="Settings_Proxy_TorSf">Tor with Snowflake</string>
   <string name="Settings_Proxy_Custom">Custom Proxy</string>
   <string name="Settings_Proxy_Custom_Value">Custom Proxy URL</string>
   <string name="Settings_Proxy_Custom_Protocol">Custom proxy protocol</string>