blob: 12dbd96ae4c8cf63bc54256f2f3cf39122d649d5 [file] [log] [blame]
/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2013-2017 Regents of the University of California.
*
* This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
*
* ndn-cxx library is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
*
* You should have received copies of the GNU General Public License and GNU Lesser
* General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
* <http://www.gnu.org/licenses/>.
*
* See AUTHORS.md for complete list of ndn-cxx authors and contributors.
*/
#ifndef NDN_UTIL_DIGEST_HPP
#define NDN_UTIL_DIGEST_HPP
#include "../encoding/block.hpp"
#include "../encoding/buffer-stream.hpp"
#include "../security/transform/step-source.hpp"
namespace ndn {
namespace util {
/**
* @brief Provides stateful SHA-256 digest calculation.
*
* Example:
* @code
* Sha256 digest;
* digest.update(buf1, size1);
* digest.update(buf2, size2);
* ...
* ConstBufferPtr result = digest.computeDigest();
* @endcode
*/
class Sha256
{
public:
class Error : public std::runtime_error
{
public:
explicit
Error(const std::string& what)
: std::runtime_error(what)
{
}
};
/**
* @brief Length in bytes of a SHA-256 digest.
*/
static const size_t DIGEST_SIZE = 32;
/**
* @brief Create an empty SHA-256 digest.
*/
Sha256();
/**
* @brief Calculate SHA-256 digest of the input stream @p is.
*/
explicit
Sha256(std::istream& is);
/**
* @brief Check if digest is empty.
*
* An empty digest means nothing has been taken into calculation.
*/
bool
empty() const
{
return m_isEmpty;
}
/**
* @brief Discard the current state and start a new digest calculation.
*/
void
reset();
/**
* @brief Finalize and return the digest based on all previously supplied inputs.
*/
ConstBufferPtr
computeDigest();
/**
* @brief Check if the supplied digest is equal to this digest.
* @note This method invokes computeDigest() on both operands, finalizing the digest.
*/
bool
operator==(Sha256& digest);
/**
* @brief Check if the supplied digest is not equal to this digest.
* @note This method invokes computeDigest() on both operands, finalizing the digest.
*/
bool
operator!=(Sha256& digest)
{
return !(*this == digest);
}
/**
* @brief Add existing digest to the digest calculation.
* @param src digest to combine with
*
* The result of this combination is `sha256(sha256(...))`
*
* @note This method invokes computeDigest() on @p src, finalizing the digest.
* @throw Error the digest has already been finalized
*/
Sha256&
operator<<(Sha256& src);
/**
* @brief Add a string to the digest calculation.
* @throw Error the digest has already been finalized
*/
Sha256&
operator<<(const std::string& str);
/**
* @brief Add a block to the digest calculation.
* @throw Error the digest has already been finalized
*/
Sha256&
operator<<(const Block& block);
/**
* @brief Add a uint64_t value to the digest calculation.
* @throw Error the digest has already been finalized
*/
Sha256&
operator<<(uint64_t value);
/**
* @brief Add a raw buffer to the digest calculation.
* @param buffer the input buffer
* @param size the size of the input buffer
* @throw Error the digest has already been finalized
*/
void
update(const uint8_t* buffer, size_t size);
/**
* @brief Convert digest to std::string.
* @note This method invokes computeDigest(), finalizing the digest.
*/
std::string
toString();
/**
* @brief Stateless SHA-256 digest calculation.
* @param buffer the input buffer
* @param size the size of the input buffer
* @return SHA-256 digest of the input buffer
*/
static ConstBufferPtr
computeDigest(const uint8_t* buffer, size_t size);
private:
unique_ptr<security::transform::StepSource> m_input;
unique_ptr<OBufferStream> m_output;
bool m_isEmpty;
bool m_isFinalized;
};
std::ostream&
operator<<(std::ostream& os, Sha256& digest);
} // namespace util
} // namespace ndn
#endif // NDN_UTIL_DIGEST_HPP