| /* |
| * Copyright (C) 2004-2023 Savoir-faire Linux Inc. |
| * |
| * This program is free software: you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation, either version 3 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program. If not, see <https://www.gnu.org/licenses/>. |
| */ |
| #include "diffie-hellman.h" |
| #include "fileutils.h" |
| |
| #include <chrono> |
| #include <ciso646> |
| #include <filesystem> |
| |
| namespace dhtnet { |
| namespace tls { |
| |
| DhParams::DhParams(const std::vector<uint8_t>& data) |
| { |
| gnutls_dh_params_t new_params_; |
| int ret = gnutls_dh_params_init(&new_params_); |
| if (ret) |
| throw std::runtime_error(std::string("Error initializing DH params: ") |
| + gnutls_strerror(ret)); |
| params_.reset(new_params_); |
| const gnutls_datum_t dat {(uint8_t*) data.data(), (unsigned) data.size()}; |
| if (int ret_pem = gnutls_dh_params_import_pkcs3(params_.get(), &dat, GNUTLS_X509_FMT_PEM)) |
| if (int ret_der = gnutls_dh_params_import_pkcs3(params_.get(), &dat, GNUTLS_X509_FMT_DER)) |
| throw std::runtime_error(std::string("Error importing DH params: ") |
| + gnutls_strerror(ret_pem) + " " + gnutls_strerror(ret_der)); |
| } |
| |
| DhParams& |
| DhParams::operator=(const DhParams& other) |
| { |
| if (not params_) { |
| // We need a valid DH params pointer for the copy |
| gnutls_dh_params_t new_params_; |
| auto err = gnutls_dh_params_init(&new_params_); |
| if (err != GNUTLS_E_SUCCESS) |
| throw std::runtime_error(std::string("Error initializing DH params: ") |
| + gnutls_strerror(err)); |
| params_.reset(new_params_); |
| } |
| |
| auto err = gnutls_dh_params_cpy(params_.get(), other.get()); |
| if (err != GNUTLS_E_SUCCESS) |
| throw std::runtime_error(std::string("Error copying DH params: ") + gnutls_strerror(err)); |
| |
| return *this; |
| } |
| |
| std::vector<uint8_t> |
| DhParams::serialize() const |
| { |
| if (!params_) { |
| // JAMI_WARN("serialize() called on an empty DhParams"); |
| return {}; |
| } |
| gnutls_datum_t out; |
| if (gnutls_dh_params_export2_pkcs3(params_.get(), GNUTLS_X509_FMT_PEM, &out)) |
| return {}; |
| std::vector<uint8_t> ret {out.data, out.data + out.size}; |
| gnutls_free(out.data); |
| return ret; |
| } |
| |
| DhParams |
| DhParams::generate() |
| { |
| using clock = std::chrono::high_resolution_clock; |
| |
| auto bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, |
| /* GNUTLS_SEC_PARAM_HIGH */ GNUTLS_SEC_PARAM_HIGH); |
| // JAMI_DBG("Generating DH params with %u bits", bits); |
| auto start = clock::now(); |
| |
| gnutls_dh_params_t new_params_; |
| int ret = gnutls_dh_params_init(&new_params_); |
| if (ret != GNUTLS_E_SUCCESS) { |
| // JAMI_ERR("Error initializing DH params: %s", gnutls_strerror(ret)); |
| return {}; |
| } |
| DhParams params {new_params_}; |
| |
| ret = gnutls_dh_params_generate2(params.get(), bits); |
| if (ret != GNUTLS_E_SUCCESS) { |
| // JAMI_ERR("Error generating DH params: %s", gnutls_strerror(ret)); |
| return {}; |
| } |
| |
| std::chrono::duration<double> time_span = clock::now() - start; |
| // JAMI_DBG("Generated DH params with %u bits in %lfs", bits, time_span.count()); |
| return params; |
| } |
| |
| DhParams |
| DhParams::loadDhParams(const std::filesystem::path& path) |
| { |
| std::lock_guard l(fileutils::getFileLock(path)); |
| try { |
| // writeTime throw exception if file doesn't exist |
| auto writeTime = std::filesystem::last_write_time(path); |
| auto duration = decltype(writeTime)::clock::now() - writeTime; |
| if (duration >= std::chrono::hours(24 * 3)) // file is valid only 3 days |
| throw std::runtime_error("file too old"); |
| |
| // JAMI_DBG("Loading DhParams from file '%s'", path.c_str()); |
| return {fileutils::loadFile(path)}; |
| } catch (const std::exception& e) { |
| // JAMI_DBG("Failed to load DhParams file '%s': %s", path.c_str(), e.what()); |
| if (auto params = tls::DhParams::generate()) { |
| try { |
| fileutils::saveFile(path, params.serialize(), 0600); |
| // JAMI_DBG("Saved DhParams to file '%s'", path.c_str()); |
| } catch (const std::exception& ex) { |
| // JAMI_WARN("Failed to save DhParams in file '%s': %s", path.c_str(), ex.what()); |
| } |
| return params; |
| } |
| // JAMI_ERR("Unable to generate DH params."); |
| return {}; |
| } |
| } |
| |
| } // namespace tls |
| } // namespace dhtnet |