digest.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012, 2013 Ripple Labs Inc.
 
    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#ifndef RIPPLE_PROTOCOL_DIGEST_H_INCLUDED
#define RIPPLE_PROTOCOL_DIGEST_H_INCLUDED
 
#include <ripple/basics/base_uint.h>
#include <ripple/beast/crypto/ripemd.h>
#include <ripple/beast/crypto/sha2.h>
#include <ripple/beast/hash/endian.h>
#include <algorithm>
#include <array>
 
namespace ripple {
 
/*  Message digest functions used in the Ripple Protocol
 
    Modeled to meet the requirements of `Hasher` in the
    `hash_append` interface, currently in proposal:
 
    N3980 "Types Don't Know #"
    http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3980.html
*/
 
//------------------------------------------------------------------------------
 
struct openssl_ripemd160_hasher
{
public:
    static beast::endian const endian =
        beast::endian::native;
 
    using result_type =
        std::array<std::uint8_t, 20>;
 
    openssl_ripemd160_hasher();
 
    void
    operator()(void const* data,
        std::size_t size) noexcept;
 
    explicit
    operator result_type() noexcept;
 
private:
    char ctx_[96];
};
 
struct openssl_sha512_hasher
{
public:
    static beast::endian const endian =
        beast::endian::native;
 
    using result_type =
        std::array<std::uint8_t, 64>;
 
    openssl_sha512_hasher();
 
    void
    operator()(void const* data,
        std::size_t size) noexcept;
 
    explicit
    operator result_type() noexcept;
 
private:
    char ctx_[216];
};
 
struct openssl_sha256_hasher
{
public:
    static beast::endian const endian =
        beast::endian::native;
 
    using result_type =
        std::array<std::uint8_t, 32>;
 
    openssl_sha256_hasher();
 
    void
    operator()(void const* data,
        std::size_t size) noexcept;
 
    explicit
    operator result_type() noexcept;
 
private:
    char ctx_[112];
};
 
//------------------------------------------------------------------------------
 
// Aliases to choose the correct digest implementation
 
#if USE_BEAST_HASHER
using ripemd160_hasher = beast::ripemd160_hasher;
using sha256_hasher = beast::sha256_hasher;
using sha512_hasher = beast::sha512_hasher;
#else
using ripemd160_hasher = openssl_ripemd160_hasher;
using sha256_hasher = openssl_sha256_hasher;
using sha512_hasher = openssl_sha512_hasher;
#endif
 
//------------------------------------------------------------------------------
 
struct ripesha_hasher
{
private:
    sha256_hasher h_;
 
public:
    static beast::endian const endian =
        beast::endian::native;
 
    using result_type =
        std::array<std::uint8_t, 20>;
 
    void
    operator()(void const* data,
        std::size_t size) noexcept
    {
        h_(data, size);
    }
 
    explicit
    operator result_type() noexcept
    {
        auto const d0 =
            sha256_hasher::result_type(h_);
        ripemd160_hasher rh;
        rh(d0.data(), d0.size());
        return ripemd160_hasher::result_type(rh);
    }
};
 
//------------------------------------------------------------------------------
 
namespace detail {
 
template <bool Secure>
struct basic_sha512_half_hasher
{
private:
    sha512_hasher h_;
 
public:
    static beast::endian const endian =
        beast::endian::big;
 
    using result_type = uint256;
 
    ~basic_sha512_half_hasher()
    {
        erase(std::integral_constant<
            bool, Secure>{});
    }
 
    void
    operator()(void const* data,
        std::size_t size) noexcept
    {
        h_(data, size);
    }
 
    explicit
    operator result_type() noexcept
    {
        auto const digest =
            sha512_hasher::result_type(h_);
        result_type result;
        std::copy(digest.begin(),
            digest.begin() + 32, result.begin());
        return result;
    }
 
private:
    inline
    void
    erase (std::false_type)
    {
    }
 
    inline
    void
    erase (std::true_type)
    {
        beast::secure_erase(&h_, sizeof(h_));
    }
};
 
} // detail
 
using sha512_half_hasher =
    detail::basic_sha512_half_hasher<false>;
 
// secure version
using sha512_half_hasher_s =
    detail::basic_sha512_half_hasher<true>;
 
//------------------------------------------------------------------------------
 
#ifdef _MSC_VER
// Call from main to fix magic statics pre-VS2015
inline
void
sha512_deprecatedMSVCWorkaround()
{
    beast::sha512_hasher h;
    auto const digest = static_cast<
        beast::sha512_hasher::result_type>(h);
}
#endif
 
template <class... Args>
sha512_half_hasher::result_type
sha512Half (Args const&... args)
{
    sha512_half_hasher h;
    using beast::hash_append;
    hash_append(h, args...);
    return static_cast<typename
        sha512_half_hasher::result_type>(h);
}
 
template <class... Args>
sha512_half_hasher_s::result_type
sha512Half_s (Args const&... args)
{
    sha512_half_hasher_s h;
    using beast::hash_append;
    hash_append(h, args...);
    return static_cast<typename
        sha512_half_hasher_s::result_type>(h);
}
 
} // ripple
 
#endif