chromium/crypto/openssl_util.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CRYPTO_OPENSSL_UTIL_H_
#define CRYPTO_OPENSSL_UTIL_H_

#include <stddef.h>
#include <string.h>

#include "base/location.h"
#include "base/memory/raw_ptr.h"
#include "crypto/crypto_export.h"

namespace crypto {

// Provides a buffer of at least MIN_SIZE bytes, for use when calling OpenSSL's
// SHA256, HMAC, etc functions, adapting the buffer sizing rules to meet those
// of our base wrapper APIs.
// This allows the library to write directly to the caller's buffer if it is of
// sufficient size, but if not it will write to temporary |min_sized_buffer_|
// of required size and then its content is automatically copied out on
// destruction, with truncation as appropriate.
template<int MIN_SIZE>
class ScopedOpenSSLSafeSizeBuffer { … };

// 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 FROM_HERE as the |location|.
CRYPTO_EXPORT void ClearOpenSSLERRStack(const base::Location& location);

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

}  // namespace crypto

#endif  // CRYPTO_OPENSSL_UTIL_H_