Mark untrusted certificates as such in Linux UI.

net/base/cert_database_nss.cc

Index: net/base/cert_database_nss.cc
diff --git a/net/base/cert_database_nss.cc b/net/base/cert_database_nss.cc
index e198e3504be82298c9b3354b0ae08e81be425a1f..e3f2d6306bd296bdde2d054607a9a1278bda4182 100644
--- a/net/base/cert_database_nss.cc
+++ b/net/base/cert_database_nss.cc
@@ -21,6 +21,12 @@
 #include "net/third_party/mozilla_security_manager/nsNSSCertTrust.h"
 #include "net/third_party/mozilla_security_manager/nsPKCS12Blob.h"
 
+// In NSS 3.13, CERTDB_VALID_PEER was renamed CERTDB_TERMINAL_RECORD. So we use
+// the new name of the macro.
+#if !defined(CERTDB_TERMINAL_RECORD)
+#define CERTDB_TERMINAL_RECORD CERTDB_VALID_PEER
+#endif
+
 // PSM = Mozilla's Personal Security Manager.
 namespace psm = mozilla_security_manager;
 
@@ -236,6 +242,40 @@ CertDatabase::TrustBits CertDatabase::GetCertTrust(const X509Certificate* cert,
   }
 }
 
+bool CertDatabase::IsUntrusted(const X509Certificate* cert) const {
+  CERTCertTrust nsstrust;
+  SECStatus rv = CERT_GetCertTrust(cert->os_cert_handle(), &nsstrust);
+  if (rv != SECSuccess) {
+    LOG(ERROR) << "CERT_GetCertTrust failed with error " << PORT_GetError();
+    return false;
+  }
+
+  // Handle explicitly distrusted certificates.
+  static const unsigned int kTrusted = CERTDB_TRUSTED_CA | CERTDB_TRUSTED;
+  const bool has_no_trust_flags =
+      (nsstrust.sslFlags & kTrusted) == 0 &&
+      (nsstrust.emailFlags & kTrusted) == 0 &&
+      (nsstrust.objectSigningFlags & kTrusted) == 0;
+
+  unsigned int flags = SEC_GET_TRUST_FLAGS(&nsstrust, trustSSL);
+  if (flags & CERTDB_TERMINAL_RECORD) {

[wtc, 2011/09/21 21:49:21]

Also the CERTDB_TERMINAL_RECORD bit needs to be tested
in nsstrust.sslFlags, nsstrust.emailFlags, and
nsstrust.objectSigningFlags separately.  (There could be
three terminal trust records.)

You can just revert to the CertDatabase::IsUntrusted logic
in Patch Set 3.

+    // In a terminal trust record, three bits may be set: CERTDB_VALID_CA,
+    // CERTDB_TRUSTED_CA, and CERTDB_TRUSTED.  The CERTDB_VALID_CA bit is
+    // irrelevant to distrust, so we don't test that bit.
+    return has_no_trust_flags;

[wtc, 2011/09/21 19:01:13]

The boolean expression has_no_trust_flags is wrong for
explicit distrust.

For explicit distrust, we need to use || instead of &&.
That is, if a cert is only explicitly distrusted for SSL,
we still want to flag it as untrusted, agreed?

+  }
+
+  // Self-signed certificates that don't have any trust bits set are untrusted.
+  // Other certificates that don't have any trust bits set may still be trusted
+  // if they chain up to a trust anchor.
+  if (CERT_CompareName(&cert->os_cert_handle()->issuer,
+                       &cert->os_cert_handle()->subject) == SECEqual) {
+    return has_no_trust_flags;
+  }
+
+  return false;
+}
+
 bool CertDatabase::SetCertTrust(const X509Certificate* cert,
                                 CertType type,
                                 TrustBits trust_bits) {