/**
 * Copyright (c) 2018 Cornell University.
 *
 * Author: Ted Yin <tederminant@gmail.com>
 *
 * 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.
 */

#ifndef _SALTICIDAE_CRYPTO_H
#define _SALTICIDAE_CRYPTO_H

#include "salticidae/type.h"
#include <openssl/sha.h>

namespace salticidae {

class SHA256 {
    SHA256_CTX ctx;

    public:
    SHA256() { reset(); }

    void reset() {
        if (!SHA256_Init(&ctx))
            throw std::runtime_error("openssl SHA256 init error");
    }

    template<typename T>
    void update(const T &data) {
        update(reinterpret_cast<const uint8_t *>(&*data.begin()), data.size());
    }

    void update(const bytearray_t::const_iterator &it, size_t length) {
        update(&*it, length);
    }

    void update(const uint8_t *ptr, size_t length) {
        if (!SHA256_Update(&ctx, ptr, length))
            throw std::runtime_error("openssl SHA256 update error");
    }

    void _digest(bytearray_t &md) {
        if (!SHA256_Final(&*md.begin(), &ctx))
            throw std::runtime_error("openssl SHA256 error");
    }

    void digest(bytearray_t &md) {
        md.resize(32);
        _digest(md);
    }

    bytearray_t digest() {
        bytearray_t md(32);
        _digest(md);
        return std::move(md);
    }
};

}

#endif