Added incident report for variations seed signature mismatch.

chrome/browser/metrics/variations/variations_seed_store_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/metrics/variations/variations_seed_store.h"
 
 #include "base/base64.h"
 #include "base/prefs/testing_pref_service.h"
 #include "base/sha1.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 103 matching lines @@
 
   // Check that loading a bad seed returns false and clears the pref.
   prefs.ClearPref(prefs::kVariationsSeed);
   prefs.SetString(prefs::kVariationsSeed, "this should fail");
   EXPECT_FALSE(PrefHasDefaultValue(prefs, prefs::kVariationsSeed));
   EXPECT_FALSE(seed_store.LoadSeed(&loaded_seed));
   EXPECT_TRUE(PrefHasDefaultValue(prefs, prefs::kVariationsSeed));
   EXPECT_TRUE(PrefHasDefaultValue(prefs, prefs::kVariationsSeedDate));
   EXPECT_TRUE(PrefHasDefaultValue(prefs, prefs::kVariationsSeedSignature));
 
+  // The below seed and signature pair were generated using the server's

[grt (UTC plus 2), 2014/10/14 01:28:30]

how about moving this new test into its own "GetInvalidSignature" test function?
fine-grained tests make it easier to diagnose failures. this also allows you to
use |seed_store| for the name of the store under test since it won't collide
with the TestVariationsSeedStore used throughout this function.

[Georges Khalil, 2014/10/14 13:51:09]

Done.

+  // private key.
+  const std::string base64_seed_data =
+      "CigxZDI5NDY0ZmIzZDc4ZmYxNTU2ZTViNTUxYzY0NDdjYmM3NGU1ZmQwEr0BCh9VTUEtVW5p"
+      "Zm9ybWl0eS1UcmlhbC0xMC1QZXJjZW50GICckqUFOAFCB2RlZmF1bHRKCwoHZGVmYXVsdBAB"
+      "SgwKCGdyb3VwXzAxEAFKDAoIZ3JvdXBfMDIQAUoMCghncm91cF8wMxABSgwKCGdyb3VwXzA0"
+      "EAFKDAoIZ3JvdXBfMDUQAUoMCghncm91cF8wNhABSgwKCGdyb3VwXzA3EAFKDAoIZ3JvdXBf"
+      "MDgQAUoMCghncm91cF8wORAB";
+  const std::string base64_seed_signature =
+      "MEQCIDD1IVxjzWYncun+9IGzqYjZvqxxujQEayJULTlbTGA/AiAr0oVmEgVUQZBYq5VLOSvy"
+      "96JkMYgzTkHPwbv7K/CmgA==";
+  const std::string base64_seed_signature_invalid =
+      "AEQCIDD1IVxjzWYncun+9IGzqYjZvqxxujQEayJULTlbTGA/AiAr0oVmEgVUQZBYq5VLOSvy"
+      "96JkMYgzTkHPwbv7K/CmgA==";
+
+  // Set seed and valid signature in prefs.
+  prefs.SetString(prefs::kVariationsSeed, base64_seed_data);
+  prefs.SetString(prefs::kVariationsSeedSignature, base64_seed_signature);
+
+  // We need a real VariationsSeedStore to test invalid signatures.
+  VariationsSeedStore seed_store_reel(&prefs);
+  seed_store_reel.LoadSeed(&loaded_seed);
+  std::string invalid_signature;
+  // Valid signature, so we should get an empty string.

[grt (UTC plus 2), 2014/10/14 01:28:30]

update comment

[Georges Khalil, 2014/10/14 13:51:09]

Done.

+  EXPECT_EQ(false, seed_store_reel.GetInvalidSignature(&invalid_signature));

[grt (UTC plus 2), 2014/10/14 01:28:30]

EXPECT_FALSE

[Georges Khalil, 2014/10/14 13:51:09]

Done.

+
+  prefs.SetString(prefs::kVariationsSeedSignature,
+                  base64_seed_signature_invalid);
+  seed_store_reel.LoadSeed(&loaded_seed);
+  // Invalid signature, so we should get the signature itself.
+  EXPECT_EQ(true, seed_store_reel.GetInvalidSignature(&invalid_signature));

[grt (UTC plus 2), 2014/10/14 01:28:30]

EXPECT_FALSE

[Georges Khalil, 2014/10/14 13:51:09]

Done.

+  EXPECT_EQ(invalid_signature, base64_seed_signature_invalid);
+
+  prefs.SetString(prefs::kVariationsSeedSignature, std::string());
+  seed_store_reel.LoadSeed(&loaded_seed);
+  // Empty signature, not considered invalid
+  EXPECT_EQ(false, seed_store_reel.GetInvalidSignature(&invalid_signature));

[grt (UTC plus 2), 2014/10/14 01:28:30]

EXPECT_TRUE

[Georges Khalil, 2014/10/14 13:51:09]

Done.

+
   // Check that having no seed in prefs results in a return value of false.
   prefs.ClearPref(prefs::kVariationsSeed);
   EXPECT_FALSE(seed_store.LoadSeed(&loaded_seed));
 }
 
 TEST(VariationsSeedStoreTest, StoreSeedData) {
   const variations::VariationsSeed seed = CreateTestSeed();
   const std::string serialized_seed = SerializeSeed(seed);
 
   TestingPrefServiceSimple prefs;
@@ skipping 81 matching lines @@
             seed_store.VerifySeedSignature(seed_data, base64_seed_data));
 #endif
 
   // Using a different seed should not match the signature.
   seed_data[0] = 'x';
   EXPECT_EQ(VariationsSeedStore::VARIATIONS_SEED_SIGNATURE_INVALID_SEED,
             seed_store.VerifySeedSignature(seed_data, base64_seed_signature));
 }
 
 }  // namespace chrome_variations