Only store leading 13 bits of password hash.

chrome/browser/signin/local_auth_unittest.cc

Index: chrome/browser/signin/local_auth_unittest.cc
diff --git a/chrome/browser/signin/local_auth_unittest.cc b/chrome/browser/signin/local_auth_unittest.cc
index 68ee397043ad9c9614b444ad6611043eda24453d..bf47094a16dee4d38e3417c65a7fb7a3234e1f1b 100644
--- a/chrome/browser/signin/local_auth_unittest.cc
+++ b/chrome/browser/signin/local_auth_unittest.cc
@@ -42,7 +42,7 @@ TEST(LocalAuthTest, SetAndCheckCredentials) {
   //  - The encoding exists (we can guarantee future backward compatibility).
   //  - The plaintext version of the password is not mistakenly stored anywhere.
   EXPECT_FALSE(passhash.empty());
-  EXPECT_EQ('1', passhash[0]);
+  EXPECT_EQ('2', passhash[0]);
   EXPECT_EQ(passhash.find(password), std::string::npos);
 
   std::string decodedhash;
@@ -56,3 +56,58 @@ TEST(LocalAuthTest, SetAndCheckCredentials) {
   SetLocalAuthCredentials(prof, password);  // makes different salt
   EXPECT_NE(passhash, cache.GetLocalAuthCredentialsOfProfileAtIndex(0));
 }
+
+
+TEST(LocalAuthTest, SetUpgradeAndCheckCredentials) {
+  TestingProfileManager testing_profile_manager(
+      TestingBrowserProcess::GetGlobal());
+  ASSERT_TRUE(testing_profile_manager.SetUp());
+  Profile* prof = testing_profile_manager.CreateTestingProfile("p1");
+  ProfileInfoCache& cache =
+      testing_profile_manager.profile_manager()->GetProfileInfoCache();
+
+  std::string password("Some Password");
+  size_t profile_index = cache.GetIndexOfProfileWithPath(prof->GetPath());
+  SetLocalAuthCredentialsWithEncoding(profile_index, password, '1');
+
+  // Ensure we indeed persisted the correct encoding.
+  std::string oldpasshash = cache.GetLocalAuthCredentialsOfProfileAtIndex(
+      profile_index);
+  EXPECT_EQ('1', oldpasshash[0]);
+
+  // Validate, ensure we can validate against the old encoding.
+  EXPECT_TRUE(ValidateLocalAuthCredentials(prof, password));
+
+  // Ensure we updated the encoding.
+  std::string newpasshash = cache.GetLocalAuthCredentialsOfProfileAtIndex(
+      profile_index);
+  EXPECT_EQ('2', newpasshash[0]);
+  // Encoding '2' writes fewer bytes than encoding '1'.
+  EXPECT_LE(newpasshash.length(), oldpasshash.length());
+
+  // Validate, ensure we validate against the new encoding.
+  EXPECT_TRUE(ValidateLocalAuthCredentials(prof, password));
+}
+
+TEST(LocalAuthTest, TruncateStringTo16Bits) {
+  std::string two_chars = "AB";
+  std::string three_chars = "ABC";
+  EXPECT_EQ(two_chars, TruncateStringByBits(two_chars, 16));
+  EXPECT_EQ(two_chars, TruncateStringByBits(three_chars, 16));
+}
+
+TEST(LocalAuthTest, TruncateStringTo14BitsLowBitsOnly) {
+  std::string two_chars = "A6";
+  std::string three_chars = "A6C";
+  EXPECT_EQ(two_chars, TruncateStringByBits(two_chars, 14));
+  EXPECT_EQ(two_chars, TruncateStringByBits(three_chars, 14));
+}
+
+TEST(LocalAuthTest, TruncateStringTo14BitsLowAndHighBits) {
+  std::string two_chars = "Az";
+  std::string three_chars = "AzC";
+  // 'z' = 0x7A, ':' = 0x3A.
+  std::string two_chars_truncated = "A:";
+  EXPECT_EQ(two_chars_truncated, TruncateStringByBits(two_chars, 14));
+  EXPECT_EQ(two_chars_truncated, TruncateStringByBits(three_chars, 14));
+}