Add an SSLConfigService implementation for Mac OS X

net/base/ssl_config_service_mac.cc

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2009 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.
 
-#include "net/base/ssl_config_service_win.h"
+#include "net/base/ssl_config_service_mac.h"
 
-#include "base/registry.h"
+#include <CoreFoundation/CoreFoundation.h>
+
+#include "base/scoped_cftyperef.h"
 
 using base::TimeDelta;
 using base::TimeTicks;
 
 namespace net {
 
+namespace {
+
 static const int kConfigUpdateInterval = 10;  // seconds
 
-static const wchar_t kInternetSettingsSubKeyName[] =
-    L"Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings";
+static const bool kSSL2EnabledDefaultValue = false;
+static const bool kSSL3EnabledDefaultValue = true;
+static const bool kTLS1EnabledDefaultValue = true;
 
-static const wchar_t kRevocationValueName[] = L"CertificateRevocation";
+static CFStringRef kRevocationPreferencesIdentifier =
+    CFSTR("com.apple.security.revocation");
+static CFStringRef kOCSPStyleKey = CFSTR("OCSPStyle");
+static CFStringRef kCRLStyleKey = CFSTR("CRLStyle");
+static CFStringRef kNoneRevocationValue = CFSTR("None");
+static CFStringRef kBestAttemptRevocationValue = CFSTR("BestAttempt");
+static CFStringRef kSSL2EnabledKey = CFSTR("org.chromium.ssl.ssl2");
+static CFStringRef kSSL3EnabledKey = CFSTR("org.chromium.ssl.ssl3");
+static CFStringRef kTLS1EnabledKey = CFSTR("org.chromium.ssl.tls1");
 
-static const wchar_t kProtocolsValueName[] = L"SecureProtocols";
+bool RevocationStyleIsEnabled(CFStringRef key) {
+  CFPropertyListRef plist_ref = CFPreferencesCopyValue(kOCSPStyleKey,
+      kRevocationPreferencesIdentifier, kCFPreferencesCurrentUser,
+      kCFPreferencesAnyHost);
+  if (plist_ref) {
+    scoped_cftyperef<CFPropertyListRef> scoped_plist_ref(plist_ref);
+    if (CFGetTypeID(plist_ref) == CFStringGetTypeID()) {
+      CFStringRef style = reinterpret_cast<CFStringRef>(plist_ref);
+      if (CFStringCompare(kNoneRevocationValue, style,
+                          kCFCompareCaseInsensitive))
+        return true;
+    }
+  }
+  return false;
+}
 
-// In SecureProtocols, each SSL version is represented by a bit:
-//   SSL 2.0: 0x08
-//   SSL 3.0: 0x20
-//   TLS 1.0: 0x80
-// The bits are OR'ed to form the DWORD value.  So 0xa0 means SSL 3.0 and
-// TLS 1.0.
-enum {
-  SSL2 = 0x08,
-  SSL3 = 0x20,
-  TLS1 = 0x80
-};
+inline bool SSLVersionIsEnabled(CFStringRef key, bool default_value) {
+  Boolean exists_and_valid;
+  Boolean rv = CFPreferencesGetAppBooleanValue(key,
+                                               kCFPreferencesCurrentApplication,
+                                               &exists_and_valid);
+  if (!exists_and_valid)
+    return default_value;
+  return rv;
+}
 
-// If CertificateRevocation or SecureProtocols is missing, IE uses a default
-// value.  Unfortunately the default is IE version specific.  We use WinHTTP's
-// default.
-enum {
-  REVOCATION_DEFAULT = 0,
-  PROTOCOLS_DEFAULT = SSL3 | TLS1
-};
+}  // namespace
 
-SSLConfigServiceWin::SSLConfigServiceWin() : ever_updated_(false) {
+SSLConfigServiceMac::SSLConfigServiceMac() : ever_updated_(false) {
   // We defer retrieving the settings until the first call to GetSSLConfig, to
   // avoid an expensive call on the UI thread, which could affect startup time.
 }
 
-SSLConfigServiceWin::SSLConfigServiceWin(TimeTicks now) : ever_updated_(false) {
+SSLConfigServiceMac::SSLConfigServiceMac(TimeTicks now) : ever_updated_(false) {
   UpdateConfig(now);
 }
 
-void SSLConfigServiceWin::GetSSLConfigAt(SSLConfig* config, TimeTicks now) {
+void SSLConfigServiceMac::GetSSLConfigAt(SSLConfig* config, TimeTicks now) {
   if (!ever_updated_ ||
       now - config_time_ > TimeDelta::FromSeconds(kConfigUpdateInterval))
     UpdateConfig(now);
   *config = config_info_;
 }
 
 // static
-bool SSLConfigServiceWin::GetSSLConfigNow(SSLConfig* config) {
-  RegKey internet_settings;
-  if (!internet_settings.Open(HKEY_CURRENT_USER, kInternetSettingsSubKeyName,
-                              KEY_READ))
-    return false;
+bool SSLConfigServiceMac::GetSSLConfigNow(SSLConfig* config) {
+  // Our own revocation checking flag is a binary value, but Mac OS X uses
+  // several shades of revocation checking:
+  //   - None (i.e., disabled, the default)
+  //   - BestAttempt
+  //   - RequireIfPresent
+  //   - RequireForall
+  // Mac OS X also breaks down revocation check for both CRLs and OCSP. We
+  // set our revocation flag if the system-wide settings for either OCSP
+  // or CRLs is anything other than None.
+  config->rev_checking_enabled = (RevocationStyleIsEnabled(kOCSPStyleKey) ||
+                                  RevocationStyleIsEnabled(kCRLStyleKey));
 
-  DWORD revocation;
-  if (!internet_settings.ReadValueDW(kRevocationValueName, &revocation))
-    revocation = REVOCATION_DEFAULT;
-
-  DWORD protocols;
-  if (!internet_settings.ReadValueDW(kProtocolsValueName, &protocols))
-    protocols = PROTOCOLS_DEFAULT;
-
-  config->rev_checking_enabled = (revocation != 0);
-  config->ssl2_enabled = ((protocols & SSL2) != 0);
-  config->ssl3_enabled = ((protocols & SSL3) != 0);
-  config->tls1_enabled = ((protocols & TLS1) != 0);
+  config->ssl2_enabled = SSLVersionIsEnabled(kSSL2EnabledKey,
+                                             kSSL2EnabledDefaultValue);
+  config->ssl3_enabled = SSLVersionIsEnabled(kSSL3EnabledKey,
+                                             kSSL3EnabledDefaultValue);
+  config->tls1_enabled = SSLVersionIsEnabled(kTLS1EnabledKey,
+                                             kTLS1EnabledDefaultValue);
 
   return true;
 }
 
 // static
-void SSLConfigServiceWin::SetRevCheckingEnabled(bool enabled) {
-  DWORD value = enabled;
-  RegKey internet_settings(HKEY_CURRENT_USER, kInternetSettingsSubKeyName,
-                           KEY_WRITE);
-  internet_settings.WriteValue(kRevocationValueName, value);
-  // TODO(mattm): We should call UpdateConfig after updating settings, but these
-  // methods are static.
+void SSLConfigServiceMac::SetSSL2Enabled(bool enabled) {
+  CFPreferencesSetAppValue(kSSL2EnabledKey,
+                           enabled ? kCFBooleanTrue : kCFBooleanFalse,
+                           kCFPreferencesCurrentApplication);
+  CFPreferencesAppSynchronize(kCFPreferencesCurrentApplication);
 }
 
 // static
-void SSLConfigServiceWin::SetSSL2Enabled(bool enabled) {
-  RegKey internet_settings(HKEY_CURRENT_USER, kInternetSettingsSubKeyName,
-                           KEY_READ | KEY_WRITE);
-  DWORD value;
-  if (!internet_settings.ReadValueDW(kProtocolsValueName, &value))
-    value = PROTOCOLS_DEFAULT;
-  if (enabled)
-    value |= SSL2;
-  else
-    value &= ~SSL2;
-  internet_settings.WriteValue(kProtocolsValueName, value);
-  // TODO(mattm): We should call UpdateConfig after updating settings, but these
-  // methods are static.
+void SSLConfigServiceMac::SetSSL3Enabled(bool enabled) {
+  CFPreferencesSetAppValue(kSSL3EnabledKey,
+                           enabled ? kCFBooleanTrue : kCFBooleanFalse,
+                           kCFPreferencesCurrentApplication);
+  CFPreferencesAppSynchronize(kCFPreferencesCurrentApplication);
 }
 
-void SSLConfigServiceWin::UpdateConfig(TimeTicks now) {
+// static
+void SSLConfigServiceMac::SetTLS1Enabled(bool enabled) {
+  CFPreferencesSetAppValue(kTLS1EnabledKey,
+                           enabled ? kCFBooleanTrue : kCFBooleanFalse,
+                           kCFPreferencesCurrentApplication);
+  CFPreferencesAppSynchronize(kCFPreferencesCurrentApplication);
+}
+
+// static
+void SSLConfigServiceMac::SetRevCheckingEnabled(bool enabled) {
+  // This method is provided for use by the unit tests. These settings
+  // are normally changed via the Keychain Access application's preferences
+  // dialog.
+  CFPreferencesSetValue(kOCSPStyleKey,
+      enabled ? kBestAttemptRevocationValue : kNoneRevocationValue,
+      kRevocationPreferencesIdentifier, kCFPreferencesCurrentUser,
+      kCFPreferencesAnyHost);
+  CFPreferencesSetValue(kCRLStyleKey,
+      enabled ? kBestAttemptRevocationValue : kNoneRevocationValue,
+      kRevocationPreferencesIdentifier, kCFPreferencesCurrentUser,
+      kCFPreferencesAnyHost);
+}
+
+void SSLConfigServiceMac::UpdateConfig(TimeTicks now) {
   GetSSLConfigNow(&config_info_);
   config_time_ = now;
   ever_updated_ = true;
 }
 
 }  // namespace net