chromium/third_party/openscreen/src/util/crypto/openssl_util.h

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UTIL_CRYPTO_OPENSSL_UTIL_H_
#define UTIL_CRYPTO_OPENSSL_UTIL_H_

#include <openssl/ssl.h>
#include <stddef.h>

#include <cstring>

#include "platform/base/error.h"
#include "platform/base/location.h"
#include "platform/base/macros.h"

namespace openscreen {
// Initialize OpenSSL if it isn't already initialized. This must be called
// before any other OpenSSL functions though it is safe and cheap to call this
// multiple times.
// This function is thread-safe, and OpenSSL will only ever be initialized once.
// OpenSSL will be properly shut down on program exit.
// Multiple sequential calls to EnsureOpenSSLInit or EnsureOpenSSLCleanup are
// ignored by OpenSSL itself.
void EnsureOpenSSLInit();
void EnsureOpenSSLCleanup();

// Drains the OpenSSL ERR_get_error stack. On a debug build the error codes
// are send to VLOG(1), on a release build they are disregarded. In most
// cases you should pass CURRENT_LOCATION as the |location|.
void ClearOpenSSLERRStack(const Location& location);

Error GetSSLError(const SSL* ssl, int return_code);

// Place an instance of this class on the call stack to automatically clear
// the OpenSSL error stack on function exit.
class OpenSSLErrStackTracer { … };

}  // namespace openscreen

#endif  // UTIL_CRYPTO_OPENSSL_UTIL_H_