diff --git a/Libraries/LibCore/Account.cpp b/Libraries/LibCore/Account.cpp new file mode 100644 index 00000000000..a3c054557c9 --- /dev/null +++ b/Libraries/LibCore/Account.cpp @@ -0,0 +1,207 @@ +/* + * Copyright (c) 2020, Peter Elliott + * 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. + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +namespace Core { + +static String get_salt() +{ + char random_data[12]; + AK::fill_with_random(random_data, sizeof(random_data)); + + StringBuilder builder; + builder.append("$5$"); + builder.append(encode_base64(ReadonlyBytes(random_data, sizeof(random_data)))); + + return builder.build(); +} + +static Vector get_gids(const StringView& username) +{ + Vector extra_gids; + for (auto* group = getgrent(); group; group = getgrent()) { + for (size_t i = 0; group->gr_mem[i]; ++i) { + if (username == group->gr_mem[i]) { + extra_gids.append(group->gr_gid); + break; + } + } + } + endgrent(); + return extra_gids; +} + +Result Account::from_name(const char* username) +{ + struct passwd* pwd = nullptr; + errno = 0; + pwd = getpwnam(username); + if (!pwd) { + if (errno == 0) + return String("No such user"); + + return String(strerror(errno)); + } + + Account account(pwd, get_gids(pwd->pw_name)); + endpwent(); + return account; +} + +Result Account::from_uid(uid_t uid) +{ + struct passwd* pwd = nullptr; + errno = 0; + pwd = getpwuid(uid); + if (!pwd) { + if (errno == 0) + return String("No such user"); + + return String(strerror(errno)); + } + + Account account(pwd, get_gids(pwd->pw_name)); + endpwent(); + return account; +} + +bool Account::authenticate(const char* password) const +{ + // An empty passwd field indicates that no password is required to log in. + if (m_password_hash.is_empty()) + return true; + + // FIXME: Use crypt_r if it can be built in lagom. + char* hash = crypt(password, m_password_hash.characters()); + return hash != nullptr && strcmp(hash, m_password_hash.characters()) == 0; +} + +bool Account::login() const +{ + if (setgroups(m_extra_gids.size(), m_extra_gids.data()) < 0) + return false; + + if (setgid(m_gid) < 0) + return false; + + if (setuid(m_uid) < 0) + return false; + + return true; +} + +void Account::set_password(const char* password) +{ + m_password_hash = crypt(password, get_salt().characters()); +} + +void Account::set_password_enabled(bool enabled) +{ + if (enabled && m_password_hash != "" && m_password_hash[0] == '!') { + m_password_hash = m_password_hash.substring(1, m_password_hash.length() - 1); + } else if (!enabled && (m_password_hash == "" || m_password_hash[0] != '!')) { + StringBuilder builder; + builder.append('!'); + builder.append(m_password_hash); + m_password_hash = builder.build(); + } +} + +void Account::delete_password() +{ + m_password_hash = ""; +} + +Account::Account(struct passwd* pwd, Vector extra_gids) + : m_username(pwd->pw_name) + , m_password_hash(pwd->pw_passwd) + , m_uid(pwd->pw_uid) + , m_gid(pwd->pw_gid) + , m_gecos(pwd->pw_gecos) + , m_home_directory(pwd->pw_dir) + , m_shell(pwd->pw_shell) + , m_extra_gids(extra_gids) +{ +} + +bool Account::sync() +{ + StringBuilder new_passwd_file; + + setpwent(); + + struct passwd* p; + errno = 0; + while ((p = getpwent())) { + if (p->pw_uid == m_uid) { + new_passwd_file.appendf("%s:%s:%u:%u:%s:%s:%s\n", + m_username.characters(), + m_password_hash.characters(), + m_uid, m_gid, + m_gecos.characters(), + m_home_directory.characters(), + m_shell.characters()); + + } else { + new_passwd_file.appendf("%s:%s:%u:%u:%s:%s:%s\n", + p->pw_name, p->pw_passwd, p->pw_uid, + p->pw_gid, p->pw_gecos, p->pw_dir, + p->pw_shell); + } + } + endpwent(); + + if (errno) + return false; + + String contents = new_passwd_file.build(); + + FILE* passwd_file = fopen("/etc/passwd", "w"); + if (!passwd_file) + return false; + + fwrite(contents.characters(), 1, contents.length(), passwd_file); + if (ferror(passwd_file)) { + int error = ferror(passwd_file); + fclose(passwd_file); + errno = error; + return false; + } + + fclose(passwd_file); + return true; + // FIXME: Sync extra groups. +} +} diff --git a/Libraries/LibCore/Account.h b/Libraries/LibCore/Account.h new file mode 100644 index 00000000000..ce77a1e6569 --- /dev/null +++ b/Libraries/LibCore/Account.h @@ -0,0 +1,81 @@ +/* + * Copyright (c) 2020, Peter Elliott + * 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. + * + * 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. + */ + +#pragma once + +#include +#include +#include +#include +#include +#include + +namespace Core { + +class Account { +public: + static Result from_name(const char* username); + static Result from_uid(uid_t uid); + + bool authenticate(const char* password) const; + bool login() const; + + String username() const { return m_username; } + String password_hash() const { return m_password_hash; } + + // Setters only affect in-memory copy of password. + // You must call sync to apply changes. + void set_password(const char* password); + void set_password_enabled(bool enabled); + void delete_password(); + bool has_password() const { return !m_password_hash.is_empty(); } + + uid_t uid() const { return m_uid; } + gid_t gid() const { return m_gid; } + const String& gecos() const { return m_gecos; } + const String& home_directory() const { return m_home_directory; } + const String& shell() const { return m_shell; } + const Vector& extra_gids() const { return m_extra_gids; } + + bool sync(); + +private: + Account(struct passwd* pwd, Vector extra_gids); + + String m_username; + + // Contents of passwd field in passwd entry. + // Can be empty, "x", or contain a leading '!' + String m_password_hash; + uid_t m_uid { 0 }; + gid_t m_gid { 0 }; + String m_gecos; + String m_home_directory; + String m_shell; + Vector m_extra_gids; +}; + +} diff --git a/Libraries/LibCore/CMakeLists.txt b/Libraries/LibCore/CMakeLists.txt index 8b1dfd6059e..1a7467170de 100644 --- a/Libraries/LibCore/CMakeLists.txt +++ b/Libraries/LibCore/CMakeLists.txt @@ -1,4 +1,5 @@ set(SOURCES + Account.cpp ArgsParser.cpp ConfigFile.cpp Command.cpp