oxen-core/src/common/password.cpp

// Copyright (c) 2014-2019, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//    used to endorse or promote products derived from this software without specific
//    prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers

#include "password.h"

#include <cstdio>
#include <iostream>
#include <type_traits>
#include <utility>

#if defined(_WIN32)
#include <io.h>
#include <windows.h>
#else
#include <termios.h>
#include <unistd.h>
#endif

#define EOT 0x4

namespace {
#if defined(_WIN32)
bool is_cin_tty() noexcept {
    return 0 != _isatty(_fileno(stdin));
}

bool read_from_tty(epee::wipeable_string& pass, bool hide_input) {
    HANDLE h_cin = ::GetStdHandle(STD_INPUT_HANDLE);

    DWORD mode_old;
    ::GetConsoleMode(h_cin, &mode_old);
    DWORD mode_new = mode_old & ~((hide_input ? ENABLE_ECHO_INPUT : 0) | ENABLE_LINE_INPUT);
    ::SetConsoleMode(h_cin, mode_new);

    bool r = true;
    pass.reserve(tools::password_container::max_password_size);
    std::vector<int> chlen;
    chlen.reserve(tools::password_container::max_password_size);
    while (pass.size() < tools::password_container::max_password_size) {
        DWORD read;
        wchar_t ucs2_ch;
        r = (TRUE == ::ReadConsoleW(h_cin, &ucs2_ch, 1, &read, NULL));
        r &= (1 == read);

        if (!r) {
            break;
        } else if (ucs2_ch == L'\r') {
            std::cout << std::endl;
            break;
        } else if (ucs2_ch == L'\b') {
            if (!pass.empty()) {
                int len = chlen.back();
                chlen.pop_back();
                while (len-- > 0)
                    pass.pop_back();
            }
            continue;
        }

        char utf8_ch[8] = {0};
        int len;
        if ((len = WideCharToMultiByte(
                     CP_UTF8, 0, &ucs2_ch, 1, utf8_ch, sizeof(utf8_ch), NULL, NULL)) <= 0)
            break;

        if (pass.size() + len >= tools::password_container::max_password_size)
            break;

        chlen.push_back(len);
        pass += utf8_ch;
    }

    ::SetConsoleMode(h_cin, mode_old);

    return r;
}

#else  // end WIN32

bool is_cin_tty() noexcept {
    return 0 != isatty(fileno(stdin));
}

int getch(bool hide_input) noexcept {
    struct termios tty_old;
    tcgetattr(STDIN_FILENO, &tty_old);

    struct termios tty_new;
    tty_new = tty_old;
    tty_new.c_lflag &= ~(ICANON | (hide_input ? ECHO : 0));
    tcsetattr(STDIN_FILENO, TCSANOW, &tty_new);

    int ch = getchar();

    tcsetattr(STDIN_FILENO, TCSANOW, &tty_old);

    return ch;
}

bool read_from_tty(epee::wipeable_string& aPass, bool hide_input) {
    static constexpr const char BACKSPACE = 127;

    aPass.reserve(tools::password_container::max_password_size);
    while (aPass.size() < tools::password_container::max_password_size) {
        int ch = getch(hide_input);
        if (EOF == ch || ch == EOT) {
            return false;
        } else if (ch == '\n' || ch == '\r') {
            std::cout << std::endl;
            break;
        } else if (ch == BACKSPACE) {
            if (!aPass.empty()) {
                aPass.pop_back();
                if (!hide_input)
                    std::cout << "\b\b\b   \b\b\b" << std::flush;
            } else {
                if (!hide_input)
                    std::cout << "\b\b  \b\b" << std::flush;
            }
        } else {
            aPass.push_back(ch);
        }
    }

    return true;
}

#endif  // end !WIN32

bool read_from_tty(
        const bool verify,
        const char* message,
        bool hide_input,
        epee::wipeable_string& pass1,
        epee::wipeable_string& pass2) {
    while (true) {
        if (message)
            std::cout << message << ": " << std::flush;
        if (!read_from_tty(pass1, hide_input))
            return false;
        if (verify) {
            std::cout << "Confirm password: ";
            if (!read_from_tty(pass2, hide_input))
                return false;
            if (pass1 != pass2) {
                std::cout << "Passwords do not match! Please try again." << std::endl;
                pass1.clear();
                pass2.clear();
            } else  // new password matches
                return true;
        } else
            return true;
        // No need to verify password entered at this point in the code
    }

    return false;
}

bool read_from_file(epee::wipeable_string& pass) {
    pass.reserve(tools::password_container::max_password_size);
    for (size_t i = 0; i < tools::password_container::max_password_size; ++i) {
        char ch = static_cast<char>(std::cin.get());
        if (std::cin.eof() || ch == '\n' || ch == '\r') {
            break;
        } else if (std::cin.fail()) {
            return false;
        } else {
            pass.push_back(ch);
        }
    }
    return true;
}

}  // anonymous namespace

namespace tools {
// deleted via private member
password_container::password_container() noexcept : m_password() {}
password_container::password_container(epee::wipeable_string password) noexcept :
        m_password{std::move(password)} {}

std::atomic<bool> password_container::is_prompting(false);

std::optional<password_container> password_container::prompt(
        const bool verify, const char* message, bool hide_input) {
    is_prompting = true;
    password_container pass1{};
    password_container pass2{};
    if (is_cin_tty()
                ? read_from_tty(verify, message, hide_input, pass1.m_password, pass2.m_password)
                : read_from_file(pass1.m_password)) {
        is_prompting = false;
        return {std::move(pass1)};
    }

    is_prompting = false;
    return std::nullopt;
}

std::optional<login> login::parse(
        std::string&& userpass,
        bool verify,
        const std::function<std::optional<password_container>(bool)>& prompt) {
    login out{};

    const auto loc = userpass.find(':');
    if (loc == std::string::npos) {
        auto result = prompt(verify);
        if (!result)
            return std::nullopt;

        out.password = std::move(*result);
    } else {
        out.password = password_container{userpass.substr(loc + 1)};
    }

    out.username = userpass.substr(0, loc);
    password_container wipe{std::move(userpass)};
    return {std::move(out)};
}
}  // namespace tools