net: disable ECDSA ciphersuites on platforms where we can't support it.

net/socket/ssl_client_socket_nss.cc

 // Copyright (c) 2012 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.
 
 // This file includes code SSLClientSocketNSS::DoVerifyCertComplete() derived
 // from AuthCertificateCallback() in
 // mozilla/security/manager/ssl/src/nsNSSCallbacks.cpp.
 
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
@@ skipping 90 matching lines @@
 #include "net/base/ssl_info.h"
 #include "net/base/x509_certificate_net_log_param.h"
 #include "net/ocsp/nss_ocsp.h"
 #include "net/socket/client_socket_handle.h"
 #include "net/socket/nss_ssl_util.h"
 #include "net/socket/ssl_error_params.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <wincrypt.h>
+#include "base/win/windows_version.h"
 #elif defined(OS_MACOSX)
 #include <Security/SecBase.h>
 #include <Security/SecCertificate.h>
 #include <Security/SecIdentity.h>
 #include "base/mac/mac_logging.h"
+#include "base/mac/mac_util.h"
 #elif defined(USE_NSS)
 #include <dlfcn.h>
 #endif
 
 static const int kRecvBufferSize = 4096;
 
 #if defined(OS_WIN)
 // CERT_OCSP_RESPONSE_PROP_ID is only implemented on Vista+, but it can be
 // set on Windows XP without error. There is some overhead from the server
 // sending the OCSP response if it supports the extension, for the subset of
@@ skipping 2981 matching lines @@
   }
 
   for (std::vector<uint16>::const_iterator it =
            ssl_config_.disabled_cipher_suites.begin();
        it != ssl_config_.disabled_cipher_suites.end(); ++it) {
     // This will fail if the specified cipher is not implemented by NSS, but
     // the failure is harmless.
     SSL_CipherPrefSet(nss_fd_, *it, PR_FALSE);
   }
 
+  // On some platforms we cannot verify ECDSA certificates.
+#if defined(OS_WIN)
+  if (base::win::GetVersion() < base::win::VISTA) {
+    DisableECDSA();
+  }
+#elif defined(OS_MACOSX)
+  if (!base::mac::IsOSSnowLeopardOrLater()) {
+    DisableECDSA();
+  }
+#endif

[Ryan Sleevi, 2012/08/15 00:40:27]

Seems like you can move this into NSSSSLInitSingleton (nss_ssl_util.cc), and
only have to set it once per-process rather than once-per-socket, and then
update the comment in net/base/ssl_config_service.h

[agl, 2012/08/15 01:06:20]

Good point, there's a SetDefault function too. Done.

+
 #ifdef SSL_ENABLE_SESSION_TICKETS
   // Support RFC 5077
   rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_SESSION_TICKETS, PR_TRUE);
   if (rv != SECSuccess) {
     LogFailedNSSFunction(
         net_log_, "SSL_OptionSet", "SSL_ENABLE_SESSION_TICKETS");
   }
 #else
   #error "You need to install NSS-3.12 or later to build chromium"
 #endif
@@ skipping 376 matching lines @@
     return;
   valid_thread_id_ = base::PlatformThread::CurrentId();
 }
 
 bool SSLClientSocketNSS::CalledOnValidThread() const {
   EnsureThreadIdAssigned();
   base::AutoLock auto_lock(lock_);
   return valid_thread_id_ == base::PlatformThread::CurrentId();
 }
 
+void SSLClientSocketNSS::DisableECDSA() {
+  const PRUint16* ciphersuites = SSL_GetImplementedCiphers();
+  const unsigned num_ciphersuites = SSL_GetNumImplementedCiphers();
+  SECStatus rv;
+  SSLCipherSuiteInfo info;
+
+  for (unsigned i = 0; i < num_ciphersuites; i++) {
+    rv = SSL_GetCipherSuiteInfo(ciphersuites[i], &info, sizeof(info));
+    if (rv != SECSuccess) {
+      LogFailedNSSFunction(net_log_, "SSL_GetCipherSuiteInfo", "");
+      LOG(ERROR) << "SSL_GetCipherSuiteInfo failed";
+      break;
+    }
+    if (info.authAlgorithm == ssl_auth_ecdsa) {
+      SSL_CipherPrefSet(nss_fd_, ciphersuites[i], PR_FALSE);
+    }
+  }
+}
+
 ServerBoundCertService* SSLClientSocketNSS::GetServerBoundCertService() const {
   return server_bound_cert_service_;
 }
 
 }  // namespace net