diff options
Diffstat (limited to 'src/lib/cryptolink/crypto_hash.h')
| -rw-r--r-- | src/lib/cryptolink/crypto_hash.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/src/lib/cryptolink/crypto_hash.h b/src/lib/cryptolink/crypto_hash.h new file mode 100644 index 0000000..f5ea3fa --- /dev/null +++ b/src/lib/cryptolink/crypto_hash.h @@ -0,0 +1,144 @@ +// Copyright (C) 2014-2017 Internet Systems Consortium, Inc. ("ISC") +// +// This Source Code Form is subject to the terms of the Mozilla Public +// License, v. 2.0. If a copy of the MPL was not distributed with this +// file, You can obtain one at http://mozilla.org/MPL/2.0/. + +#include <util/buffer.h> + +#include <boost/noncopyable.hpp> + +#include <cryptolink/cryptolink.h> + +#ifndef ISC_CRYPTO_HASH_H +#define ISC_CRYPTO_HASH_H + +namespace isc { +namespace cryptolink { + +/// Forward declaration, pimpl style +class HashImpl; + +/// \brief Hash support +/// +/// This class is used to create Hash digests. Instances +/// can be created with CryptoLink::createHash() +/// +class Hash : private boost::noncopyable { +private: + /// \brief Constructor from a hash algorithm + /// + /// \exception UnsupportedAlgorithmException if the given algorithm + /// is unknown or not supported by the underlying library + /// \exception LibraryError if there was any unexpected exception + /// in the underlying library + /// + /// \param hash_algorithm The hash algorithm + Hash(const HashAlgorithm hash_algorithm); + + friend Hash* CryptoLink::createHash(const HashAlgorithm); + +public: + /// \brief Destructor + ~Hash(); + + /// \brief Returns the HashAlgorithm of the object + /// + /// \return hash algorithm + HashAlgorithm getHashAlgorithm() const; + + /// \brief Returns the output size of the digest + /// + /// \return output size of the digest + size_t getOutputLength() const; + + /// \brief Add data to digest + /// + /// \exception LibraryError if there was any unexpected exception + /// in the underlying library + /// + /// \param data The data to add + /// \param len The size of the data + void update(const void* data, const size_t len); + + /// \brief Calculate the final digest + /// + /// The result will be appended to the given outputbuffer + /// + /// \exception LibraryError if there was any unexpected exception + /// in the underlying library + /// + /// \param result The OutputBuffer to append the result to + /// \param len The number of bytes from the result to copy. If this + /// value is smaller than the algorithms output size, the + /// result will be truncated. If this value is larger, + /// only output size bytes will be copied + void final(isc::util::OutputBuffer& result, size_t len); + + /// \brief Calculate the final digest + /// + /// len bytes of data from the result will be copied to *result + /// If len is larger than the output size, only output_size bytes + /// will be copied. If it is smaller, the output will be truncated + /// + /// \exception LibraryError if there was any unexpected exception + /// in the underlying library + /// + /// At least len bytes of data must be available for writing at + /// result. + /// + /// \param result The memory location the digest will be written to + /// \param len Specifies the size of the result location available + void final(void* result, size_t len); + + /// \brief Calculate the final digest + /// + /// The result will be returned as a std::vector<uint8_t> + /// + /// \exception LibraryError if there was any unexpected exception + /// in the underlying library + /// + /// \param len The number of bytes from the result to copy. If this + /// value is smaller than the algorithms output size, the + /// result will be truncated. If this value is larger, + /// only output size bytes will be copied + /// \return a vector containing the signature + std::vector<uint8_t> final(size_t len); + +private: + HashImpl* impl_; +}; + +/// \brief Create an Hash digest for the given data +/// +/// This is a convenience function that calculates the hash digest, +/// given a fixed amount of data. Internally it does the same as +/// creating an Hash object, feeding it the data, and calculating the +/// resulting digest. +/// +/// \exception UnsupportedAlgorithm if the given algorithm is unknown +/// or not supported by the underlying library +/// \exception LibraryError if there was any unexpected exception +/// in the underlying library +/// +/// \param data The data to digest +/// \param data_len The length of the data +/// \param hash_algorithm The hash algorithm +/// \param result The digest will be appended to this buffer +/// \param len If this is non-zero and less than the output size, the result +/// will be truncated to len bytes. If greater than output size +/// (or equal to zero) only output size bytes are written +void digest(const void* data, + const size_t data_len, + const HashAlgorithm hash_algorithm, + isc::util::OutputBuffer& result, + size_t len = 0); + +/// \brief Delete an Hash object +void deleteHash(Hash* hash); + +} // namespace cryptolink +} // namespace isc + +#endif // ISC_CRYPTO_HASH_H + |