Verify intent signatures.

chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandler.java

Index: chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandler.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandler.java b/chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandler.java
index 99c2a0418e6c33bcb9d4d677230334e3549929bd..864650352bb039debbef5d7e1fb8a7751d3649e1 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandler.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationHandler.java
@@ -7,6 +7,7 @@ package org.chromium.chrome.browser.externalnav;
 import android.content.ActivityNotFoundException;
 import android.content.ComponentName;
 import android.content.Intent;
+import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.net.Uri;
 import android.os.SystemClock;
@@ -28,8 +29,10 @@ import org.chromium.chrome.browser.util.UrlUtilities;
 import org.chromium.ui.base.PageTransition;
 
 import java.net.URI;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
 /**
@@ -112,6 +115,10 @@ public class ExternalNavigationHandler {
             browserFallbackUrl = null;
         }
 
+        if (!intentPackageSignatureMatches(intent)) {
+            return OverrideUrlLoadingResult.NO_OVERRIDE;
+        }
+
         long time = SystemClock.elapsedRealtime();
         OverrideUrlLoadingResult result = shouldOverrideUrlLoadingInternal(
                 params, intent, hasBrowserFallbackUrl, browserFallbackUrl);
@@ -127,6 +134,71 @@ public class ExternalNavigationHandler {
         return result;
     }
 
+    /**
+     * When a custom scheme intent trying to launch another application, verify the signature
+     * fingerprint of intent, if the fingerprint matches fingerprints of target application, the
+     * intent should be override, or it shouldn't.
+     *
+     * @param intent intent from url
+     * @return boolean, true if the feature is not supported or url should override,
+     * false if the the intent should not override.
+     */
+    private boolean intentPackageSignatureMatches(Intent intent) {
+        try {
+            //This new feature is based on custom scheme, string "scheme" used to check whether

[please use gerrit instead, 2016/07/29 16:59:52]

1) "//" should always be followed by " " before the actual comment begins. See
Line 100 for example.

2) Remove the word "new". This feature will be old soon enough.

+            //the intent url has extra custom scheme, if not, the new feature won't work.
+            String scheme = intent.getData().getScheme();
+            String fragment = intent.getData().getFragment();
+            if (!TextUtils.isEmpty(scheme) && fragment != null && fragment.contains(";")) {
+                String[] parts = fragment.split(";");
+                Set<Set<String>> allFingerPrint256 = new HashSet<>();
+                //Consider that apks could have same package name, different keystores.
+                //1. An apk's signature may update and differ from old, so you might need config and
+                //support new and old signatures, but this is optional. (e.g. (1)only config new
+                //fingerprint. (2)only config old fingerprint.(3)config new and old fingerprint)
+                //2. An apk itself may contain more than one keystore to sign.
+                //example: suppose apk's new signature is sha256_1,sha256_2,and old signature
+                //is sha256_3. You can config the intent like "...;sha256=sha256_1,sha256_2;..."
+                //or "...;sha256=sha256_1,sha256_2|sha256_3;..."
+                String pkgName = "";
+                String fingerPrint256 = "";
+                String[] fingerPrint256DifGroups;
+                for (int i = 0; i < parts.length; ++i) {
+                    String[] part = parts[i].split("=");
+                    if (part[0].equals("sha256")) {
+                        fingerPrint256 = part[1];
+                    }
+                    if (part[0].equals("package")) {
+                        pkgName = part[1];
+                    }
+                }
+                if (!TextUtils.isEmpty(pkgName) && !TextUtils.isEmpty(fingerPrint256)) {
+                    fingerPrint256DifGroups = fingerPrint256.split("\\|");
+                    for (int i = 0; i < fingerPrint256DifGroups.length; ++i) {
+                        Set<String> fingerPrint256GroupSignKeySet = new HashSet<>();
+                        Collections.addAll(fingerPrint256GroupSignKeySet, fingerPrint256DifGroups[i]
+                                .split(","));
+                        allFingerPrint256.add(fingerPrint256GroupSignKeySet);
+                    }
+                    Set<String> fingerPrint256Set = mDelegate.getPackageSHA256Fingerprints(pkgName);
+                    if (!allFingerPrint256.contains(fingerPrint256Set)) {
+                        return false;
+                    }
+                }
+            }
+        } catch (PackageManager.NameNotFoundException e) {

[please use gerrit instead, 2016/07/29 16:59:52]

Modify getPackageSHA256FingerPrints() to return null on failure instead of
throwing an exception. Then check fingerPrint256Set for null before using it.

+            return false;
+        } catch (Throwable ignore) {

[please use gerrit instead, 2016/07/29 16:59:52]

Don't surround large blocks of code with try-catch blocks, especially with such
a generic exception type as Throwable. This will easily hide bugs in your code.

+            //1. In method getPackageSHA256Fingerprints() , if no SHA-256 implementation found,
+            //we consider this new feature won't work, so it should reset to the original way
+            //to handle the intent , we should ignore ths throwable.
+            //2. In the process above, any other exception or error happens except
+            //"NameNotFoundException", we can consider the feature fail ,and catch the throwable
+            // and continue next work.
+        }
+        return true;
+    }
+
     private boolean resolversSubsetOf(List<ResolveInfo> infos, List<ResolveInfo> container) {
         HashSet<ComponentName> containerSet = new HashSet<>();
         for (ResolveInfo info : container) {