From 337d0847463b997559d099b02020c93d644b146b Mon Sep 17 00:00:00 2001
From: Richard Newman <rnewman@mozilla.com>
Date: Thu, 4 Jun 2015 11:07:32 -0700
Subject: [PATCH] Bug 1061273 - Part 2: use per-version DEFAULT_PROTOCOLS and
 DEFAULT_CIPHER_SUITES. r=nalexander

---
 .../background/common/GlobalConstants.java    | 75 ++++++++++++++++---
 1 file changed, 64 insertions(+), 11 deletions(-)

diff --git a/mobile/android/base/background/common/GlobalConstants.java b/mobile/android/base/background/common/GlobalConstants.java
index 6d8b98d9235..e0204452d5c 100644
--- a/mobile/android/base/background/common/GlobalConstants.java
+++ b/mobile/android/base/background/common/GlobalConstants.java
@@ -38,23 +38,76 @@ public class GlobalConstants {
 
   // Acceptable cipher suites.
   /**
+   * We support only a very limited range of strong cipher suites and protocols:
+   * no SSLv3 or TLSv1.0 (if we can), no DHE ciphers that might be vulnerable to Logjam
+   * (https://weakdh.org/), no RC4.
+   *
+   * Backstory: Bug 717691 (we no longer support Android 2.2, so the name
+   * workaround is unnecessary), Bug 1081953, Bug 1061273, Bug 1166839.
+   *
    * See <http://developer.android.com/reference/javax/net/ssl/SSLSocket.html> for
    * supported Android versions for each set of protocols and cipher suites.
+   *
+   * Note that currently we need to support connections to Sync 1.1 on Mozilla-hosted infra,
+   * as well as connections to FxA and Sync 1.5 on AWS.
+   *
+   * ELB cipher suites:
+   * <http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/elb-security-policy-table.html>
    */
   public static final String[] DEFAULT_CIPHER_SUITES;
   public static final String[] DEFAULT_PROTOCOLS;
 
   static {
-    DEFAULT_CIPHER_SUITES = new String[]
-        {
-          "TLS_DHE_RSA_WITH_AES_256_CBC_SHA",
-          "TLS_DHE_RSA_WITH_AES_128_CBC_SHA",
-          "SSL_RSA_WITH_RC4_128_SHA", // "RC4_SHA"
-        };
-    DEFAULT_PROTOCOLS = new String[]
-        {
-          "SSLv3",
-          "TLSv1",
-        };
+    // Prioritize 128 over 256 as a tradeoff between device CPU/battery and the minor
+    // increase in strength.
+    if (Versions.feature20Plus) {
+      DEFAULT_CIPHER_SUITES = new String[]
+          {
+           "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",   // 20+
+           "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",     // 20+
+           "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",     // 20+
+           "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA",        // 11+
+           "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",     // 20+
+           "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384",     // 20+
+           "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA",        // 11+
+          };
+    } else if (Versions.feature11Plus) {
+      DEFAULT_CIPHER_SUITES = new String[]
+          {
+           "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA",        // 11+
+           "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA",      // 11+
+           "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA",        // 11+
+           "TLS_RSA_WITH_AES_256_CBC_SHA",              // 9+
+          };
+    } else {       // 9+
+      // Fall back to the only half-decent cipher suites supported on Gingerbread.
+      // N.B., there appears to be *no overlap* between the ELB 2015-05 default
+      // suites and Gingerbread. A custom configuration is needed if moving beyond
+      // the 2015-03 defaults.
+      DEFAULT_CIPHER_SUITES = new String[]
+          {
+           // This is for Sync 1.5 on ELB 2015-03.
+           "TLS_DHE_RSA_WITH_AES_128_CBC_SHA",
+           "TLS_DHE_DSS_WITH_AES_128_CBC_SHA",
+
+           // This is for Sync 1.1.
+           "TLS_DHE_RSA_WITH_AES_256_CBC_SHA",          // 9+
+           "TLS_RSA_WITH_AES_256_CBC_SHA",              // 9+
+          };
+    }
+
+    if (Versions.feature16Plus) {
+      DEFAULT_PROTOCOLS = new String[]
+          {
+           "TLSv1.2",
+           "TLSv1.1",
+          };
+    } else {
+      // Fall back to TLSv1 if there's nothing better.
+      DEFAULT_PROTOCOLS = new String[]
+          {
+           "TLSv1",
+          };
+    }
   }
 }