Add a DevTools warning for a missing subjectAltName

net/cert/x509_util_nss.cc

Index: net/cert/x509_util_nss.cc
diff --git a/net/cert/x509_util_nss.cc b/net/cert/x509_util_nss.cc
index 04c34c565f851619cc9da956a387a398ea8f410a..2988417673b0a2fadb044217032857bee4f7a15d 100644
--- a/net/cert/x509_util_nss.cc
+++ b/net/cert/x509_util_nss.cc
@@ -159,7 +159,7 @@ std::string ParseSerialNumber(const CERTCertificate* certificate) {
                      certificate->serialNumber.len);
 }
 
-void GetSubjectAltName(CERTCertificate* cert_handle,
+bool GetSubjectAltName(CERTCertificate* cert_handle,
                        std::vector<std::string>* dns_names,
                        std::vector<std::string>* ip_addrs) {
   if (dns_names)
@@ -171,34 +171,45 @@ void GetSubjectAltName(CERTCertificate* cert_handle,
   SECStatus rv = CERT_FindCertExtension(
       cert_handle, SEC_OID_X509_SUBJECT_ALT_NAME, &alt_name);
   if (rv != SECSuccess)
-    return;
+    return false;
 
-  PLArenaPool* arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);
-  DCHECK(arena != NULL);
+  crypto::ScopedPLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE));
 
   CERTGeneralName* alt_name_list;
-  alt_name_list = CERT_DecodeAltNameExtension(arena, &alt_name);
+  alt_name_list = CERT_DecodeAltNameExtension(arena.get(), &alt_name);
   SECITEM_FreeItem(&alt_name, PR_FALSE);
 
+  bool has_san = false;
   CERTGeneralName* name = alt_name_list;
   while (name) {
     // DNSName and IPAddress are encoded as IA5String and OCTET STRINGs
     // respectively, both of which can be byte copied from
     // SECItemType::data into the appropriate output vector.
-    if (dns_names && name->type == certDNSName) {
-      dns_names->push_back(
-          std::string(reinterpret_cast<char*>(name->name.other.data),
-                      name->name.other.len));
-    } else if (ip_addrs && name->type == certIPAddress) {
-      ip_addrs->push_back(
-          std::string(reinterpret_cast<char*>(name->name.other.data),
-                      name->name.other.len));
+    if (name->type == certDNSName) {
+      has_san = true;
+      if (dns_names) {
+        dns_names->push_back(
+            std::string(reinterpret_cast<char*>(name->name.other.data),
+                        name->name.other.len));
+      }
+    } else if (name->type == certIPAddress) {
+      has_san = true;
+      if (ip_addrs) {
+        ip_addrs->push_back(
+            std::string(reinterpret_cast<char*>(name->name.other.data),
+                        name->name.other.len));
+      }
     }
+    // Fast path: Found at least one subjectAltName and the caller doesn't
+    // need the actual values.
+    if (has_san && !ip_addrs && !dns_names)
+      return true;
+
     name = CERT_GetNextGeneralName(name);
     if (name == alt_name_list)
       break;
   }
-  PORT_FreeArena(arena, PR_FALSE);
+  return has_san;
 }
 
 void GetRFC822SubjectAltNames(CERTCertificate* cert_handle,