src/ssl/ring_buffer_bio.hpp

/*
  Licensed to the Apache Software Foundation (ASF) under one
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  distributed with this work for additional information
  regarding copyright ownership.  The ASF licenses this file
  to you 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

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  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.
*/

// Based on the ring buffer implementation in
// NodeBIO (https://github.com/joyent/node/blob/master/src/node_crypto_bio.h).
// The following is the license for that implementation:

// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef DATASTAX_INTERNAL_RING_BUFFER_BIO_HPP
#define DATASTAX_INTERNAL_RING_BUFFER_BIO_HPP

#include "ring_buffer.hpp"

#include <assert.h>
#include <openssl/bio.h>

#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
#define BIO_get_data(b) ((b)->ptr)
#endif

namespace datastax { namespace internal { namespace rb {

// This wrapper is used to contain the ring buffer state kept in the BIO's
// user data field. OpenSSL 1.1 made the BIO's structure opaque which removed access
// to the "num" field which was used for the EOF return value. This struct's "ret"
// is now used to track the EOF return value.
struct RingBufferState {
  RingBufferState(RingBuffer* ring_buffer)
      : ring_buffer(ring_buffer)
      , ret(-1) {}

  RingBuffer* ring_buffer;
  int ret; // Used to keep track of the EOF return value
};

class RingBufferBio {
public:
  static BIO* create(RingBufferState* ring_buffer);

  static RingBufferState* from_bio(BIO* bio) {
    assert(BIO_get_data(bio) != NULL);
    return static_cast<RingBufferState*>(BIO_get_data(bio));
  }

#if OPENSSL_VERSION_NUMBER >= 0x10100000L
  static void initialize();
  static void cleanup();
#endif

private:
  static int create(BIO* bio);
  static int destroy(BIO* bio);
  static int read(BIO* bio, char* out, int len);
  static int write(BIO* bio, const char* data, int len);
  static int puts(BIO* bio, const char* str);
  static int gets(BIO* bio, char* out, int size);
  static long ctrl(BIO* bio, int cmd, long num, void* ptr);

#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
  static const BIO_METHOD method_;
#else
  static BIO_METHOD* method_;
#endif
};

}}} // namespace datastax::internal::rb

#endif