Update SSL error handling code to account for Subject CN deprecation

components/ssl_errors/error_classification_unittest.cc

Index: components/ssl_errors/error_classification_unittest.cc
diff --git a/components/ssl_errors/error_classification_unittest.cc b/components/ssl_errors/error_classification_unittest.cc
index 1099181a6f459b175c4a92cdcebd5479afb91721..9abd39d3518bf741e6340dfc9500550da512f0d4 100644
--- a/components/ssl_errors/error_classification_unittest.cc
+++ b/components/ssl_errors/error_classification_unittest.cc
@@ -53,112 +53,124 @@ class SSLErrorClassificationTest : public ::testing::Test {
 };
 
 TEST_F(SSLErrorClassificationTest, TestNameMismatch) {
-  scoped_refptr<net::X509Certificate> google_cert(
-      net::X509Certificate::CreateFromBytes(
-          reinterpret_cast<const char*>(google_der), sizeof(google_der)));
-  ASSERT_TRUE(google_cert.get());
-  std::vector<std::string> dns_names_google;
-  google_cert->GetDNSNames(&dns_names_google);
-  ASSERT_EQ(1u, dns_names_google.size());  // ["www.google.com"]
-  std::vector<std::string> hostname_tokens_google =
-      ssl_errors::Tokenize(dns_names_google[0]);
-  ASSERT_EQ(3u, hostname_tokens_google.size());  // ["www","google","com"]
-  std::vector<std::vector<std::string>> dns_name_tokens_google;
-  dns_name_tokens_google.push_back(hostname_tokens_google);
-  ASSERT_EQ(1u, dns_name_tokens_google.size());  // [["www","google","com"]]
+  scoped_refptr<net::X509Certificate> example_cert = net::ImportCertFromFile(
+      net::GetTestCertsDirectory(), "subjectAltName_www_example_com.pem");
+  ASSERT_TRUE(example_cert.get());
+  std::vector<std::string> dns_names_example;
+  example_cert->GetDNSNames(&dns_names_example);
+  ASSERT_EQ(1u, dns_names_example.size());  // ["www.example.com"]

[Ryan Sleevi, 2017/03/31 14:51:34]

JUDGEMENT CALL NIT:
ASSERT_THAT(dns_names_example, ElementsAre("www.example.com"));

(If you want the GMock version, which apparently is the internal recommendation.
I'm torn on that recommendation myself (not a fan), but I wouldn't be a good
reviewer if I didn't highlight the changing winds of style :)

[elawrence, 2017/03/31 16:09:41]

Neat. I'd rather the code do the testing than leave the comments that explained
what they hoped the test found.

+  std::vector<std::string> hostname_tokens_example =
+      ssl_errors::Tokenize(dns_names_example[0]);
+  ASSERT_EQ(3u, hostname_tokens_example.size());  // ["www","example","com"]
+  std::vector<std::vector<std::string>> dns_name_tokens_example;
+  dns_name_tokens_example.push_back(hostname_tokens_example);
+  ASSERT_EQ(1u, dns_name_tokens_example.size());  // [["www","example","com"]]
 
   {
-    GURL origin("https://google.com");
+    GURL origin("https://example.com");
     std::string www_host;
     std::vector<std::string> host_name_tokens = base::SplitString(
         origin.host(), ".", base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
     EXPECT_TRUE(
-        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_google, &www_host));
-    EXPECT_EQ("www.google.com", www_host);
+        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_example, &www_host));
+    EXPECT_EQ("www.example.com", www_host);
     EXPECT_FALSE(ssl_errors::NameUnderAnyNames(host_name_tokens,
-                                               dns_name_tokens_google));
-    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_google,
+                                               dns_name_tokens_example));
+    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_example,
                                                host_name_tokens));
-    EXPECT_FALSE(ssl_errors::IsSubDomainOutsideWildcard(origin, *google_cert));
+    EXPECT_FALSE(ssl_errors::IsSubDomainOutsideWildcard(origin, *example_cert));
     EXPECT_FALSE(
-        ssl_errors::IsCertLikelyFromMultiTenantHosting(origin, *google_cert));
-    EXPECT_TRUE(ssl_errors::IsCertLikelyFromSameDomain(origin, *google_cert));
+        ssl_errors::IsCertLikelyFromMultiTenantHosting(origin, *example_cert));
+    EXPECT_TRUE(ssl_errors::IsCertLikelyFromSameDomain(origin, *example_cert));
   }
 
   {
-    GURL origin("https://foo.blah.google.com");
+    GURL origin("https://foo.blah.example.com");
     std::string www_host;
     std::vector<std::string> host_name_tokens = base::SplitString(
         origin.host(), ".", base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
     EXPECT_FALSE(
-        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_google, &www_host));
+        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_example, &www_host));
     EXPECT_FALSE(ssl_errors::NameUnderAnyNames(host_name_tokens,
-                                               dns_name_tokens_google));
-    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_google,
+                                               dns_name_tokens_example));
+    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_example,
                                                host_name_tokens));
-    EXPECT_TRUE(ssl_errors::IsCertLikelyFromSameDomain(origin, *google_cert));
+    EXPECT_TRUE(ssl_errors::IsCertLikelyFromSameDomain(origin, *example_cert));
   }
 
   {
-    GURL origin("https://foo.www.google.com");
+    GURL origin("https://foo.www.example.com");
     std::string www_host;
     std::vector<std::string> host_name_tokens = base::SplitString(
         origin.host(), ".", base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
     EXPECT_FALSE(
-        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_google, &www_host));
+        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_example, &www_host));
     EXPECT_TRUE(ssl_errors::NameUnderAnyNames(host_name_tokens,
-                                              dns_name_tokens_google));
-    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_google,
+                                              dns_name_tokens_example));
+    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_example,
                                                host_name_tokens));
-    EXPECT_TRUE(ssl_errors::IsCertLikelyFromSameDomain(origin, *google_cert));
+    EXPECT_TRUE(ssl_errors::IsCertLikelyFromSameDomain(origin, *example_cert));
   }
 
   {
-    GURL origin("https://www.google.com.foo");
+    GURL origin("https://www.example.com.foo");
     std::string www_host;
     std::vector<std::string> host_name_tokens = base::SplitString(
         origin.host(), ".", base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
     EXPECT_FALSE(
-        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_google, &www_host));
+        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_example, &www_host));
     EXPECT_FALSE(ssl_errors::NameUnderAnyNames(host_name_tokens,
-                                               dns_name_tokens_google));
-    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_google,
+                                               dns_name_tokens_example));
+    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_example,
                                                host_name_tokens));
-    EXPECT_FALSE(ssl_errors::IsCertLikelyFromSameDomain(origin, *google_cert));
+    EXPECT_FALSE(ssl_errors::IsCertLikelyFromSameDomain(origin, *example_cert));
   }
 
   {
-    GURL origin("https://www.foogoogle.com.");
+    GURL origin("https://www.fooexample.com.");
     std::string www_host;
     std::vector<std::string> host_name_tokens = base::SplitString(
         origin.host(), ".", base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
     EXPECT_FALSE(
-        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_google, &www_host));
+        ssl_errors::GetWWWSubDomainMatch(origin, dns_names_example, &www_host));
     EXPECT_FALSE(ssl_errors::NameUnderAnyNames(host_name_tokens,
-                                               dns_name_tokens_google));
-    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_google,
+                                               dns_name_tokens_example));
+    EXPECT_FALSE(ssl_errors::AnyNamesUnderName(dns_name_tokens_example,
                                                host_name_tokens));
+    EXPECT_FALSE(ssl_errors::IsCertLikelyFromSameDomain(origin, *example_cert));
+  }
+
+  // Ensure that a certificate with no SubjectAltNames does not fall back to
+  // the Subject CN when evaluating hostnames.
+  {
+    scoped_refptr<net::X509Certificate> google_cert(
+        net::X509Certificate::CreateFromBytes(
+            reinterpret_cast<const char*>(google_der), sizeof(google_der)));
+    ASSERT_TRUE(google_cert.get());
+
+    GURL origin("https://google.com");
+    EXPECT_FALSE(ssl_errors::IsWWWSubDomainMatch(origin, *google_cert));
     EXPECT_FALSE(ssl_errors::IsCertLikelyFromSameDomain(origin, *google_cert));
   }
 
-  scoped_refptr<net::X509Certificate> webkit_cert(
-      net::X509Certificate::CreateFromBytes(
-          reinterpret_cast<const char*>(webkit_der), sizeof(webkit_der)));
-  ASSERT_TRUE(webkit_cert.get());
-  std::vector<std::string> dns_names_webkit;
-  webkit_cert->GetDNSNames(&dns_names_webkit);
-  ASSERT_EQ(2u, dns_names_webkit.size());  // ["*.webkit.org", "webkit.org"]
-  std::vector<std::string> hostname_tokens_webkit_0 =
-      ssl_errors::Tokenize(dns_names_webkit[0]);
-  ASSERT_EQ(3u, hostname_tokens_webkit_0.size());  // ["*", "webkit","org"]
-  std::vector<std::string> hostname_tokens_webkit_1 =
-      ssl_errors::Tokenize(dns_names_webkit[1]);
-  ASSERT_EQ(2u, hostname_tokens_webkit_1.size());  // ["webkit","org"]
-  std::vector<std::vector<std::string>> dns_name_tokens_webkit;
-  dns_name_tokens_webkit.push_back(hostname_tokens_webkit_0);
-  dns_name_tokens_webkit.push_back(hostname_tokens_webkit_1);
-  ASSERT_EQ(2u, dns_name_tokens_webkit.size());
   {
+    scoped_refptr<net::X509Certificate> webkit_cert(
+        net::X509Certificate::CreateFromBytes(
+            reinterpret_cast<const char*>(webkit_der), sizeof(webkit_der)));
+    ASSERT_TRUE(webkit_cert.get());
+    std::vector<std::string> dns_names_webkit;
+    webkit_cert->GetDNSNames(&dns_names_webkit);
+    ASSERT_EQ(2u, dns_names_webkit.size());  // ["*.webkit.org", "webkit.org"]
+    std::vector<std::string> hostname_tokens_webkit_0 =
+        ssl_errors::Tokenize(dns_names_webkit[0]);
+    ASSERT_EQ(3u, hostname_tokens_webkit_0.size());  // ["*", "webkit","org"]
+    std::vector<std::string> hostname_tokens_webkit_1 =
+        ssl_errors::Tokenize(dns_names_webkit[1]);
+    ASSERT_EQ(2u, hostname_tokens_webkit_1.size());  // ["webkit","org"]
+    std::vector<std::vector<std::string>> dns_name_tokens_webkit;
+    dns_name_tokens_webkit.push_back(hostname_tokens_webkit_0);
+    dns_name_tokens_webkit.push_back(hostname_tokens_webkit_1);
+    ASSERT_EQ(2u, dns_name_tokens_webkit.size());
     GURL origin("https://a.b.webkit.org");
     std::string www_host;
     std::vector<std::string> host_name_tokens = base::SplitString(