/*
 * Copyright (C) 2015 Southern Storm Software, Pty Ltd.
 *
 * 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.
 */

#include "Hash.h"

/**
 * \class Hash Hash.h <Hash.h>
 * \brief Abstract base class for cryptographic hash algorithms.
 *
 * \sa SHA1, SHA256
 */

/**
 * \brief Constructs a new hash object.
 */
Hash::Hash()
{
}

/**
 * \brief Destroys this hash object.
 *
 * \note Subclasses are responsible for clearing any sensitive data
 * that remains in the hash object when it is destroyed.
 *
 * \sa clear()
 */
Hash::~Hash()
{
}

/**
 * \fn size_t Hash::hashSize() const
 * \brief Size of the hash result from finalize().
 *
 * \sa finalize(), blockSize()
 */

/**
 * \fn size_t Hash::blockSize() const
 * \brief Size of the internal block used by the hash algorithm.
 *
 * \sa update(), hashSize()
 */

/**
 * \fn void Hash::reset()
 * \brief Resets the hash ready for a new hashing process.
 *
 * \sa update(), finalize()
 */

/**
 * \fn void Hash::update(const void *data, size_t len)
 * \brief Updates the hash with more data.
 *
 * \param data Data to be hashed.
 * \param len Number of bytes of data to be hashed.
 *
 * If finalize() has already been called, then calling update() will
 * reset() the hash and start a new hashing process.
 *
 * \sa reset(), finalize()
 */

/**
 * \fn void Hash::finalize(void *hash, size_t len)
 * \brief Finalizes the hashing process and returns the hash.
 *
 * \param hash The buffer to return the hash value in.
 * \param len The length of the \a hash buffer, normally hashSize().
 *
 * If \a len is less than hashSize(), then the hash value will be
 * truncated to the first \a len bytes.  If \a len is greater than
 * hashSize(), then the remaining bytes will left unchanged.
 *
 * If finalize() is called again, the same hash value is returned again until
 * the next call to reset() or update().
 *
 * \sa reset(), update()
 */

/**
 * \fn void Hash::clear()
 * \brief Clears the hash state, removing all sensitive data, and then
 * resets the hash ready for a new hashing process.
 *
 * \sa reset()
 */