prf_x942.hpp

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//---------------------------------------------------------------------------//
// Copyright (c) 2019 Mikhail Komarov <nemo@nil.foundation>
//
// MIT License
//
// 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 CRYPTO3_KDF_ANSI_X942_PRF_HPP
#define CRYPTO3_KDF_ANSI_X942_PRF_HPP
 
#include <nil/crypto3/kdf/detail/prf_x942/prf_x942_functions.hpp>
 
#include <nil/crypto3/hash/sha1.hpp>
 
#include <vector>
 
namespace nil {
    namespace crypto3 {
        namespace kdf {
            template<typename Hash = hash::sha1>
            class x942_prf {
                typedef detail::prf_x942_functions<Hash> policy_type;
 
            public:
                typedef typename policy_type::hash_type hash_type;
 
                static void process() {
                    const OID kek_algo(m_key_wrap_oid);
 
                    std::vector<uint8_t> h;
                    std::vector<uint8_t> in;
                    size_t offset = 0;
                    uint32_t counter = 1;
 
                    in.reserve(salt_len + label_len);
                    in += std::make_pair(label, label_len);
                    in += std::make_pair(salt, salt_len);
 
                    while (offset != key_len && counter) {
                        hash->update(secret, secret_len);
 
                        hash->update(
                            der_encoder()
                                .start_cons(SEQUENCE)
 
                                .start_cons(SEQUENCE)
                                .encode(kek_algo)
                                .raw_bytes(encode_x942_int(counter))
                                .end_cons()
 
                                .encode_if(salt_len != 0,
                                           der_encoder().start_explicit(0).encode(in, OCTET_STRING).end_explicit())
 
                                .start_explicit(2)
                                .raw_bytes(encode_x942_int(static_cast<uint32_t>(8 * key_len)))
                                .end_explicit()
 
                                .end_cons()
                                .get_contents());
 
                        hash->final(h);
                        const size_t copied = std::min(h.size(), key_len - offset);
                        copy_mem(&key[offset], h.data(), copied);
                        offset += copied;
 
                        ++counter;
                    }
 
                    return offset;
                }
            };
        }    // namespace kdf
    }        // namespace crypto3
}    // namespace nil
 
#endif