// 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.

#include "net/ssl/ssl_config_service.h"

#include "base/lazy_instance.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "net/cert/crl_set.h"
#include "net/ssl/ssl_config_service_defaults.h"

#if defined(USE_OPENSSL)
#include <openssl/ssl.h>
#endif

namespace net {

static uint16 g_default_version_min = SSL_PROTOCOL_VERSION_SSL3;

static uint16 g_default_version_max =
#if defined(USE_OPENSSL)
#if defined(SSL_OP_NO_TLSv1_2)
    SSL_PROTOCOL_VERSION_TLS1_2;
#elif defined(SSL_OP_NO_TLSv1_1)
    SSL_PROTOCOL_VERSION_TLS1_1;
#else
    SSL_PROTOCOL_VERSION_TLS1;
#endif
#else
    SSL_PROTOCOL_VERSION_TLS1_2;
#endif

SSLConfig::CertAndStatus::CertAndStatus() : cert_status(0) {}

SSLConfig::CertAndStatus::~CertAndStatus() {}

SSLConfig::SSLConfig()
    : rev_checking_enabled(false),
      rev_checking_required_local_anchors(false),
      version_min(g_default_version_min),
      version_max(g_default_version_max),
      cached_info_enabled(false),
      channel_id_enabled(true),
      false_start_enabled(true),
      signed_cert_timestamps_enabled(true),
      require_forward_secrecy(false),
      unrestricted_ssl3_fallback_enabled(false),
      send_client_cert(false),
      verify_ev_cert(false),
      version_fallback(false),
      cert_io_enabled(true) {
}

SSLConfig::~SSLConfig() {
}

bool SSLConfig::IsAllowedBadCert(X509Certificate* cert,
                                 CertStatus* cert_status) const {
  std::string der_cert;
  if (!X509Certificate::GetDEREncoded(cert->os_cert_handle(), &der_cert))
    return false;
  return IsAllowedBadCert(der_cert, cert_status);
}

bool SSLConfig::IsAllowedBadCert(const base::StringPiece& der_cert,
                                 CertStatus* cert_status) const {
  for (size_t i = 0; i < allowed_bad_certs.size(); ++i) {
    if (der_cert == allowed_bad_certs[i].der_cert) {
      if (cert_status)
        *cert_status = allowed_bad_certs[i].cert_status;
      return true;
    }
  }
  return false;
}

SSLConfigService::SSLConfigService()
    : observer_list_(ObserverList<Observer>::NOTIFY_EXISTING_ONLY) {
}

static bool g_cached_info_enabled = false;

// GlobalCRLSet holds a reference to the global CRLSet. It simply wraps a lock
// around a scoped_refptr so that getting a reference doesn't race with
// updating the CRLSet.
class GlobalCRLSet {
 public:
  void Set(const scoped_refptr<CRLSet>& new_crl_set) {
    base::AutoLock locked(lock_);
    crl_set_ = new_crl_set;
  }

  scoped_refptr<CRLSet> Get() const {
    base::AutoLock locked(lock_);
    return crl_set_;
  }

 private:
  scoped_refptr<CRLSet> crl_set_;
  mutable base::Lock lock_;
};

base::LazyInstance<GlobalCRLSet>::Leaky g_crl_set = LAZY_INSTANCE_INITIALIZER;

// static
void SSLConfigService::SetCRLSet(scoped_refptr<CRLSet> crl_set) {
  // Note: this can be called concurently with GetCRLSet().
  g_crl_set.Get().Set(crl_set);
}

// static
scoped_refptr<CRLSet> SSLConfigService::GetCRLSet() {
  return g_crl_set.Get().Get();
}

void SSLConfigService::EnableCachedInfo() {
  g_cached_info_enabled = true;
}

// static
bool SSLConfigService::cached_info_enabled() {
  return g_cached_info_enabled;
}

// static
uint16 SSLConfigService::default_version_min() {
  return g_default_version_min;
}

// static
uint16 SSLConfigService::default_version_max() {
  return g_default_version_max;
}

void SSLConfigService::AddObserver(Observer* observer) {
  observer_list_.AddObserver(observer);
}

void SSLConfigService::RemoveObserver(Observer* observer) {
  observer_list_.RemoveObserver(observer);
}

void SSLConfigService::NotifySSLConfigChange() {
  FOR_EACH_OBSERVER(Observer, observer_list_, OnSSLConfigChanged());
}

SSLConfigService::~SSLConfigService() {
}

// static
void SSLConfigService::SetSSLConfigFlags(SSLConfig* ssl_config) {
  ssl_config->cached_info_enabled = g_cached_info_enabled;
}

void SSLConfigService::ProcessConfigUpdate(const SSLConfig& orig_config,
                                           const SSLConfig& new_config) {
  bool config_changed =
      (orig_config.rev_checking_enabled != new_config.rev_checking_enabled) ||
      (orig_config.rev_checking_required_local_anchors !=
       new_config.rev_checking_required_local_anchors) ||
      (orig_config.version_min != new_config.version_min) ||
      (orig_config.version_max != new_config.version_max) ||
      (orig_config.disabled_cipher_suites !=
       new_config.disabled_cipher_suites) ||
      (orig_config.channel_id_enabled != new_config.channel_id_enabled) ||
      (orig_config.false_start_enabled != new_config.false_start_enabled) ||
      (orig_config.require_forward_secrecy !=
       new_config.require_forward_secrecy) ||
      (orig_config.unrestricted_ssl3_fallback_enabled !=
       new_config.unrestricted_ssl3_fallback_enabled);

  if (config_changed)
    NotifySSLConfigChange();
}

// static
bool SSLConfigService::IsSNIAvailable(SSLConfigService* service) {
  if (!service)
    return false;

  SSLConfig ssl_config;
  service->GetSSLConfig(&ssl_config);
  return ssl_config.version_max >= SSL_PROTOCOL_VERSION_TLS1;
}

}  // namespace net