/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This code is made available to you under your choice of the following sets

 * of licensing terms:

 */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 */

/* Copyright 2013 Mozilla Contributors

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#ifndef mozilla_psm_OCSPCache_h

#define mozilla_psm_OCSPCache_h

#include "hasht.h"

#include "mozilla/Mutex.h"

#include "mozilla/Vector.h"

#include "pkix/Result.h"

#include "pkix/Time.h"

#include "prerror.h"

#include "seccomon.h"

namespace mozilla {

class OriginAttributes;

}

namespace mozilla { namespace pkix {

struct CertID;

} } // namespace mozilla::pkix

namespace mozilla { namespace psm {

// make SHA384Buffer be of type "array of uint8_t of length SHA384_LENGTH"

typedef uint8_t SHA384Buffer[SHA384_LENGTH];

// OCSPCache can store and retrieve OCSP response verification results. Each

// result is keyed on the certificate that purportedly corresponds to it (where

// certificates are distinguished based on serial number, issuer, and

// issuer public key, much like in an encoded OCSP response itself). A maximum

// of 1024 distinct entries can be stored.

// OCSPCache is thread-safe.

class OCSPCache

{

public:

  OCSPCache();

  ~OCSPCache();

  // Returns true if the status of the given certificate (issued by the given

  // issuer) is in the cache, and false otherwise.

  // If it is in the cache, returns by reference the error code of the cached

  // status and the time through which the status is considered trustworthy.

  // The passed in origin attributes are used to isolate the OCSP cache.

  // We currently only use the first party domain portion of the attributes, and

  // it is non-empty only when "privacy.firstParty.isolate" is enabled.

  bool Get(const mozilla::pkix::CertID& aCertID,

           const OriginAttributes& aOriginAttributes,

           /*out*/ mozilla::pkix::Result& aResult,

           /*out*/ mozilla::pkix::Time& aValidThrough);

  // Caches the status of the given certificate (issued by the given issuer).

  // The status is considered trustworthy through the given time.

  // A status with an error code of SEC_ERROR_REVOKED_CERTIFICATE will not

  // be replaced or evicted.

  // A status with an error code of SEC_ERROR_OCSP_UNKNOWN_CERT will not

  // be evicted when the cache is full.

  // A status with a more recent thisUpdate will not be replaced with a

  // status with a less recent thisUpdate unless the less recent status

  // indicates the certificate is revoked.

  // The passed in origin attributes are used to isolate the OCSP cache.

  // We currently only use the first party domain portion of the attributes, and

  // it is non-empty only when "privacy.firstParty.isolate" is enabled.

  mozilla::pkix::Result Put(const mozilla::pkix::CertID& aCertID,

                            const OriginAttributes& aOriginAttributes,

                            mozilla::pkix::Result aResult,

                            mozilla::pkix::Time aThisUpdate,

                            mozilla::pkix::Time aValidThrough);

  // Removes everything from the cache.

  void Clear();

private:

  class Entry

  {

  public:

    Entry(mozilla::pkix::Result aResult,

          mozilla::pkix::Time aThisUpdate,

          mozilla::pkix::Time aValidThrough)

      : mResult(aResult)

      , mThisUpdate(aThisUpdate)

      , mValidThrough(aValidThrough)

    {

    }

    mozilla::pkix::Result Init(const mozilla::pkix::CertID& aCertID,

                               const OriginAttributes& aOriginAttributes);

    mozilla::pkix::Result mResult;

    mozilla::pkix::Time mThisUpdate;

    mozilla::pkix::Time mValidThrough;

    // The SHA-384 hash of the concatenation of the DER encodings of the

    // issuer name and issuer key, followed by the length of the serial number,

    // the serial number, the length of the first party domain, and the first

    // party domain (if "privacy.firstparty.isolate" is enabled).

    // See the documentation for CertIDHash in OCSPCache.cpp.

    SHA384Buffer mIDHash;

  };

  bool FindInternal(const mozilla::pkix::CertID& aCertID,

                    const OriginAttributes& aOriginAttributes,

                    /*out*/ size_t& index,

                    const MutexAutoLock& aProofOfLock);

  void MakeMostRecentlyUsed(size_t aIndex, const MutexAutoLock& aProofOfLock);

  Mutex mMutex;

  static const size_t MaxEntries = 1024;

  // Sorted with the most-recently-used entry at the end.

  // Using 256 here reserves as much possible inline storage as the vector

  // implementation will give us. 1024 bytes is the maximum it allows,

  // which results in 256 Entry pointers or 128 Entry pointers, depending

  // on the size of a pointer.

  Vector<Entry*, 256> mEntries;

};

} } // namespace mozilla::psm

#endif // mozilla_psm_OCSPCache_h