SHA_224.hpp

#ifndef _SNARKFRONT_SHA_224_HPP_
#define _SNARKFRONT_SHA_224_HPP_

#include <array>
#include <cstdint>
#include "Alg.hpp"
#include "Alg_uint.hpp"
#include "AST.hpp"
#include "BitwiseOps.hpp"
#include "Lazy.hpp"
#include "SHA_256.hpp"

namespace snarkfront {

////////////////////////////////////////////////////////////////////////////////
// SHA-224
//

template <typename T, typename MSG, typename F>
class SHA_224 : public SHA_256<T, MSG, F>
{
public:
    typedef T WordType;
    typedef std::array<T, 16> MsgType;
    typedef std::array<T, 7> DigType;

    SHA_224()
        : m_setDigest(false)
    {}

    // overrides base class SHA-256
    const std::array<T, 7>& digest() {
        if (m_setDigest) {
            for (std::size_t i = 0; i < 7; ++i) {
                m_Hleft224[i] = this->m_H[i];
            }

            m_setDigest = false;
        }

        return m_Hleft224;
    }

    // overrides base class SHA-256
    virtual void initHashValue() {
        // set initial hash value (NIST FIPS 180-4 section 5.3.2)
        const std::array<std::uint32_t, 8> a {
            0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939,
            0xffc00b31, 0x68581511, 0x64f98fa7, 0xbefa4fa4 };

        for (std::size_t i = 0; i < 8; ++i) {
            this->m_H[i] = F::constant(a[i]);
        }
    }

    virtual void afterHash() {
        m_setDigest = true;
    }

private:
    // truncated 224-bit message digest
    std::array<T, 7> m_Hleft224;

    bool m_setDigest;
};

////////////////////////////////////////////////////////////////////////////////
// typedefs
//

namespace zk {
    template <typename FR> using
    SHA224 = SHA_224<AST_Var<Alg_uint32<FR>>,
                     Lazy<AST_Var<Alg_uint32<FR>>, std::uint32_t>,
                     SHA_Functions<AST_Node<Alg_uint32<FR>>,
                                   AST_Op<Alg_uint32<FR>>,
                                   BitwiseAST<Alg_uint32<FR>, Alg_uint32<FR>>>>;
} // namespace zk

namespace eval {
    typedef SHA_224<std::uint32_t,
                    std::uint32_t,
                    SHA_Functions<std::uint32_t,
                                  std::uint32_t,
                                  BitwiseINT<std::uint32_t, std::uint32_t>>>
        SHA224;
} // namespace eval

} // namespace snarkfront

#endif