memgraph/tests/unit/auth.cpp

// Copyright 2021 Memgraph Ltd.
//
// Use of this software is governed by the Business Source License
// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
// License, and you may not use this file except in compliance with the Business Source License.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of this software will be governed
// by the Apache License, Version 2.0, included in the file
// licenses/APL.txt.

#include <algorithm>
#include <iostream>

#include <gflags/gflags.h>
#include <gtest/gtest.h>

#include "auth/auth.hpp"
#include "auth/crypto.hpp"
#include "utils/cast.hpp"
#include "utils/file.hpp"
#include "utils/license.hpp"

using namespace auth;
namespace fs = std::filesystem;

DECLARE_bool(auth_password_permit_null);
DECLARE_string(auth_password_strength_regex);

class AuthWithStorage : public ::testing::Test {
 protected:
  virtual void SetUp() {
    utils::EnsureDir(test_folder_);
    FLAGS_auth_password_permit_null = true;
    FLAGS_auth_password_strength_regex = ".+";

    utils::license::global_license_checker.EnableTesting();
  }

  virtual void TearDown() { fs::remove_all(test_folder_); }

  fs::path test_folder_{fs::temp_directory_path() / "MG_tests_unit_auth"};

  Auth auth{test_folder_ / ("unit_auth_test_" + std::to_string(static_cast<int>(getpid())))};
};

TEST_F(AuthWithStorage, AddRole) {
  ASSERT_TRUE(auth.AddRole("admin"));
  ASSERT_TRUE(auth.AddRole("user"));
  ASSERT_FALSE(auth.AddRole("admin"));
}

TEST_F(AuthWithStorage, RemoveRole) {
  ASSERT_TRUE(auth.AddRole("admin"));
  ASSERT_TRUE(auth.RemoveRole("admin"));
  ASSERT_FALSE(auth.RemoveRole("user"));
  ASSERT_FALSE(auth.RemoveRole("user"));
}

TEST_F(AuthWithStorage, AddUser) {
  ASSERT_FALSE(auth.HasUsers());
  ASSERT_TRUE(auth.AddUser("test"));
  ASSERT_TRUE(auth.HasUsers());
  ASSERT_TRUE(auth.AddUser("test2"));
  ASSERT_FALSE(auth.AddUser("test"));
}

TEST_F(AuthWithStorage, RemoveUser) {
  ASSERT_FALSE(auth.HasUsers());
  ASSERT_TRUE(auth.AddUser("test"));
  ASSERT_TRUE(auth.HasUsers());
  ASSERT_TRUE(auth.RemoveUser("test"));
  ASSERT_FALSE(auth.HasUsers());
  ASSERT_FALSE(auth.RemoveUser("test2"));
  ASSERT_FALSE(auth.RemoveUser("test"));
  ASSERT_FALSE(auth.HasUsers());
}

TEST_F(AuthWithStorage, Authenticate) {
  ASSERT_FALSE(auth.HasUsers());

  auto user = auth.AddUser("test");
  ASSERT_NE(user, std::nullopt);
  ASSERT_TRUE(auth.HasUsers());

  ASSERT_TRUE(auth.Authenticate("test", "123"));

  user->UpdatePassword("123");
  auth.SaveUser(*user);

  ASSERT_NE(auth.Authenticate("test", "123"), std::nullopt);

  ASSERT_EQ(auth.Authenticate("test", "456"), std::nullopt);
  ASSERT_NE(auth.Authenticate("test", "123"), std::nullopt);

  user->UpdatePassword();
  auth.SaveUser(*user);

  ASSERT_NE(auth.Authenticate("test", "123"), std::nullopt);
  ASSERT_NE(auth.Authenticate("test", "456"), std::nullopt);

  ASSERT_EQ(auth.Authenticate("nonexistant", "123"), std::nullopt);
}

TEST_F(AuthWithStorage, UserRolePermissions) {
  ASSERT_FALSE(auth.HasUsers());
  ASSERT_TRUE(auth.AddUser("test"));
  ASSERT_TRUE(auth.HasUsers());

  auto user = auth.GetUser("test");
  ASSERT_NE(user, std::nullopt);

  // Test initial user permissions.
  ASSERT_EQ(user->permissions().Has(Permission::MATCH), PermissionLevel::NEUTRAL);
  ASSERT_EQ(user->permissions().Has(Permission::CREATE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(user->permissions().Has(Permission::MERGE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(user->permissions().Has(Permission::DELETE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(user->permissions(), user->GetPermissions());

  // Change one user permission.
  user->permissions().Grant(Permission::MATCH);

  // Check permissions.
  ASSERT_EQ(user->permissions().Has(Permission::MATCH), PermissionLevel::GRANT);
  ASSERT_EQ(user->permissions().Has(Permission::CREATE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(user->permissions().Has(Permission::MERGE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(user->permissions().Has(Permission::DELETE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(user->permissions(), user->GetPermissions());

  // Create role.
  ASSERT_TRUE(auth.AddRole("admin"));
  auto role = auth.GetRole("admin");
  ASSERT_NE(role, std::nullopt);

  // Assign permissions to role and role to user.
  role->permissions().Grant(Permission::DELETE);
  user->SetRole(*role);

  // Check permissions.
  {
    auto permissions = user->GetPermissions();
    ASSERT_EQ(permissions.Has(Permission::MATCH), PermissionLevel::GRANT);
    ASSERT_EQ(permissions.Has(Permission::DELETE), PermissionLevel::GRANT);
    ASSERT_EQ(permissions.Has(Permission::CREATE), PermissionLevel::NEUTRAL);
    ASSERT_EQ(permissions.Has(Permission::MERGE), PermissionLevel::NEUTRAL);
  }

  // Add explicit deny to role.
  role->permissions().Deny(Permission::MATCH);
  user->SetRole(*role);

  // Check permissions.
  {
    auto permissions = user->GetPermissions();
    ASSERT_EQ(permissions.Has(Permission::MATCH), PermissionLevel::DENY);
    ASSERT_EQ(permissions.Has(Permission::DELETE), PermissionLevel::GRANT);
    ASSERT_EQ(permissions.Has(Permission::CREATE), PermissionLevel::NEUTRAL);
    ASSERT_EQ(permissions.Has(Permission::MERGE), PermissionLevel::NEUTRAL);
  }
}

TEST_F(AuthWithStorage, RoleManipulations) {
  {
    auto user1 = auth.AddUser("user1");
    ASSERT_TRUE(user1);
    auto role1 = auth.AddRole("role1");
    ASSERT_TRUE(role1);
    user1->SetRole(*role1);
    auth.SaveUser(*user1);

    auto user2 = auth.AddUser("user2");
    ASSERT_TRUE(user2);
    auto role2 = auth.AddRole("role2");
    ASSERT_TRUE(role2);
    user2->SetRole(*role2);
    auth.SaveUser(*user2);
  }

  {
    auto user1 = auth.GetUser("user1");
    ASSERT_TRUE(user1);
    const auto *role1 = user1->role();
    ASSERT_NE(role1, nullptr);
    ASSERT_EQ(role1->rolename(), "role1");

    auto user2 = auth.GetUser("user2");
    ASSERT_TRUE(user2);
    const auto *role2 = user2->role();
    ASSERT_NE(role2, nullptr);
    ASSERT_EQ(role2->rolename(), "role2");
  }

  ASSERT_TRUE(auth.RemoveRole("role1"));

  {
    auto user1 = auth.GetUser("user1");
    ASSERT_TRUE(user1);
    const auto *role = user1->role();
    ASSERT_EQ(role, nullptr);

    auto user2 = auth.GetUser("user2");
    ASSERT_TRUE(user2);
    const auto *role2 = user2->role();
    ASSERT_NE(role2, nullptr);
    ASSERT_EQ(role2->rolename(), "role2");
  }

  {
    auto role1 = auth.AddRole("role1");
    ASSERT_TRUE(role1);
  }

  {
    auto user1 = auth.GetUser("user1");
    ASSERT_TRUE(user1);
    const auto *role1 = user1->role();
    ASSERT_EQ(role1, nullptr);

    auto user2 = auth.GetUser("user2");
    ASSERT_TRUE(user2);
    const auto *role2 = user2->role();
    ASSERT_NE(role2, nullptr);
    ASSERT_EQ(role2->rolename(), "role2");
  }

  {
    auto users = auth.AllUsers();
    std::sort(users.begin(), users.end(), [](const User &a, const User &b) { return a.username() < b.username(); });
    ASSERT_EQ(users.size(), 2);
    ASSERT_EQ(users[0].username(), "user1");
    ASSERT_EQ(users[1].username(), "user2");
  }

  {
    auto roles = auth.AllRoles();
    std::sort(roles.begin(), roles.end(), [](const Role &a, const Role &b) { return a.rolename() < b.rolename(); });
    ASSERT_EQ(roles.size(), 2);
    ASSERT_EQ(roles[0].rolename(), "role1");
    ASSERT_EQ(roles[1].rolename(), "role2");
  }

  {
    auto users = auth.AllUsersForRole("role2");
    ASSERT_EQ(users.size(), 1);
    ASSERT_EQ(users[0].username(), "user2");
  }
}

TEST_F(AuthWithStorage, UserRoleLinkUnlink) {
  {
    auto user = auth.AddUser("user");
    ASSERT_TRUE(user);
    auto role = auth.AddRole("role");
    ASSERT_TRUE(role);
    user->SetRole(*role);
    auth.SaveUser(*user);
  }

  {
    auto user = auth.GetUser("user");
    ASSERT_TRUE(user);
    const auto *role = user->role();
    ASSERT_NE(role, nullptr);
    ASSERT_EQ(role->rolename(), "role");
  }

  {
    auto user = auth.GetUser("user");
    ASSERT_TRUE(user);
    user->ClearRole();
    auth.SaveUser(*user);
  }

  {
    auto user = auth.GetUser("user");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->role(), nullptr);
  }
}

TEST_F(AuthWithStorage, UserPasswordCreation) {
  {
    auto user = auth.AddUser("test");
    ASSERT_TRUE(user);
    ASSERT_TRUE(auth.Authenticate("test", "123"));
    ASSERT_TRUE(auth.Authenticate("test", "456"));
    ASSERT_TRUE(auth.RemoveUser(user->username()));
  }

  {
    auto user = auth.AddUser("test", "123");
    ASSERT_TRUE(user);
    ASSERT_TRUE(auth.Authenticate("test", "123"));
    ASSERT_FALSE(auth.Authenticate("test", "456"));
    ASSERT_TRUE(auth.RemoveUser(user->username()));
  }
}

TEST_F(AuthWithStorage, PasswordStrength) {
  const std::string kWeakRegex = ".+";
  // https://stackoverflow.com/questions/5142103/regex-to-validate-password-strength
  const std::string kStrongRegex =
      "^(?=.*[A-Z].*[A-Z])(?=.*[!@#$&*])(?=.*[0-9].*[0-9])(?=.*[a-z].*[a-z].*["
      "a-z]).{8,}$";

  const std::string kWeakPassword = "weak";
  const std::string kAlmostStrongPassword = "ThisPasswordMeetsAllButOneCriterion1234";
  const std::string kStrongPassword = "ThisIsAVeryStrongPassword123$";

  auto user = auth.AddUser("user");
  ASSERT_TRUE(user);

  FLAGS_auth_password_permit_null = true;
  FLAGS_auth_password_strength_regex = kWeakRegex;
  ASSERT_NO_THROW(user->UpdatePassword());
  ASSERT_NO_THROW(user->UpdatePassword(kWeakPassword));
  ASSERT_NO_THROW(user->UpdatePassword(kAlmostStrongPassword));
  ASSERT_NO_THROW(user->UpdatePassword(kStrongPassword));

  FLAGS_auth_password_permit_null = false;
  FLAGS_auth_password_strength_regex = kWeakRegex;
  ASSERT_THROW(user->UpdatePassword(), AuthException);
  ASSERT_NO_THROW(user->UpdatePassword(kWeakPassword));
  ASSERT_NO_THROW(user->UpdatePassword(kAlmostStrongPassword));
  ASSERT_NO_THROW(user->UpdatePassword(kStrongPassword));

  FLAGS_auth_password_permit_null = true;
  FLAGS_auth_password_strength_regex = kStrongRegex;
  ASSERT_NO_THROW(user->UpdatePassword());
  ASSERT_THROW(user->UpdatePassword(kWeakPassword), AuthException);
  ASSERT_THROW(user->UpdatePassword(kAlmostStrongPassword), AuthException);
  ASSERT_NO_THROW(user->UpdatePassword(kStrongPassword));

  FLAGS_auth_password_permit_null = false;
  FLAGS_auth_password_strength_regex = kStrongRegex;
  ASSERT_THROW(user->UpdatePassword(), AuthException);
  ASSERT_THROW(user->UpdatePassword(kWeakPassword), AuthException);
  ASSERT_THROW(user->UpdatePassword(kAlmostStrongPassword), AuthException);
  ASSERT_NO_THROW(user->UpdatePassword(kStrongPassword));
}

TEST(AuthWithoutStorage, Permissions) {
  Permissions permissions;
  ASSERT_EQ(permissions.grants(), 0);
  ASSERT_EQ(permissions.denies(), 0);

  permissions.Grant(Permission::MATCH);
  ASSERT_EQ(permissions.Has(Permission::MATCH), PermissionLevel::GRANT);
  ASSERT_EQ(permissions.grants(), utils::UnderlyingCast(Permission::MATCH));
  ASSERT_EQ(permissions.denies(), 0);

  permissions.Revoke(Permission::MATCH);
  ASSERT_EQ(permissions.Has(Permission::MATCH), PermissionLevel::NEUTRAL);
  ASSERT_EQ(permissions.grants(), 0);
  ASSERT_EQ(permissions.denies(), 0);

  permissions.Deny(Permission::MATCH);
  ASSERT_EQ(permissions.Has(Permission::MATCH), PermissionLevel::DENY);
  ASSERT_EQ(permissions.denies(), utils::UnderlyingCast(Permission::MATCH));
  ASSERT_EQ(permissions.grants(), 0);

  permissions.Grant(Permission::MATCH);
  ASSERT_EQ(permissions.Has(Permission::MATCH), PermissionLevel::GRANT);
  ASSERT_EQ(permissions.grants(), utils::UnderlyingCast(Permission::MATCH));
  ASSERT_EQ(permissions.denies(), 0);

  permissions.Deny(Permission::CREATE);
  ASSERT_EQ(permissions.Has(Permission::MATCH), PermissionLevel::GRANT);
  ASSERT_EQ(permissions.Has(Permission::CREATE), PermissionLevel::DENY);
  ASSERT_EQ(permissions.Has(Permission::MERGE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(permissions.grants(), utils::UnderlyingCast(Permission::MATCH));
  ASSERT_EQ(permissions.denies(), utils::UnderlyingCast(Permission::CREATE));

  permissions.Grant(Permission::DELETE);
  ASSERT_EQ(permissions.Has(Permission::MATCH), PermissionLevel::GRANT);
  ASSERT_EQ(permissions.Has(Permission::CREATE), PermissionLevel::DENY);
  ASSERT_EQ(permissions.Has(Permission::MERGE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(permissions.Has(Permission::DELETE), PermissionLevel::GRANT);
  ASSERT_EQ(permissions.grants(), utils::UnderlyingCast(Permission::MATCH) | utils::UnderlyingCast(Permission::DELETE));
  ASSERT_EQ(permissions.denies(), utils::UnderlyingCast(Permission::CREATE));

  permissions.Revoke(Permission::DELETE);
  ASSERT_EQ(permissions.Has(Permission::MATCH), PermissionLevel::GRANT);
  ASSERT_EQ(permissions.Has(Permission::CREATE), PermissionLevel::DENY);
  ASSERT_EQ(permissions.Has(Permission::MERGE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(permissions.Has(Permission::DELETE), PermissionLevel::NEUTRAL);
  ASSERT_EQ(permissions.grants(), utils::UnderlyingCast(Permission::MATCH));
  ASSERT_EQ(permissions.denies(), utils::UnderlyingCast(Permission::CREATE));
}

TEST(AuthWithoutStorage, PermissionsMaskTest) {
  Permissions p1(0, 0);
  ASSERT_EQ(p1.grants(), 0);
  ASSERT_EQ(p1.denies(), 0);

  Permissions p2(1, 0);
  ASSERT_EQ(p2.grants(), 1);
  ASSERT_EQ(p2.denies(), 0);

  Permissions p3(1, 1);
  ASSERT_EQ(p3.grants(), 0);
  ASSERT_EQ(p3.denies(), 1);

  Permissions p4(3, 2);
  ASSERT_EQ(p4.grants(), 1);
  ASSERT_EQ(p4.denies(), 2);
}

TEST(AuthWithoutStorage, UserSerializeDeserialize) {
  auto user = User("test");
  user.permissions().Grant(Permission::MATCH);
  user.permissions().Deny(Permission::MERGE);
  user.UpdatePassword("world");

  auto data = user.Serialize();

  auto output = User::Deserialize(data);
  ASSERT_EQ(user, output);
}

TEST(AuthWithoutStorage, RoleSerializeDeserialize) {
  auto role = Role("test");
  role.permissions().Grant(Permission::MATCH);
  role.permissions().Deny(Permission::MERGE);

  auto data = role.Serialize();

  auto output = Role::Deserialize(data);
  ASSERT_EQ(role, output);
}

TEST_F(AuthWithStorage, UserWithRoleSerializeDeserialize) {
  auto role = auth.AddRole("role");
  ASSERT_TRUE(role);
  role->permissions().Grant(Permission::MATCH);
  role->permissions().Deny(Permission::MERGE);
  auth.SaveRole(*role);

  auto user = auth.AddUser("user");
  ASSERT_TRUE(user);
  user->permissions().Grant(Permission::MATCH);
  user->permissions().Deny(Permission::MERGE);
  user->UpdatePassword("world");
  user->SetRole(*role);
  auth.SaveUser(*user);

  auto new_user = auth.GetUser("user");
  ASSERT_TRUE(new_user);
  ASSERT_EQ(*user, *new_user);
}

TEST_F(AuthWithStorage, UserRoleUniqueName) {
  ASSERT_TRUE(auth.AddUser("user"));
  ASSERT_TRUE(auth.AddRole("role"));
  ASSERT_FALSE(auth.AddRole("user"));
  ASSERT_FALSE(auth.AddUser("role"));
}

TEST(AuthWithoutStorage, CaseInsensitivity) {
  {
    auto user1 = User("test");
    auto user2 = User("Test");
    ASSERT_EQ(user1, user2);
    ASSERT_EQ(user1.username(), user2.username());
    ASSERT_EQ(user1.username(), "test");
    ASSERT_EQ(user2.username(), "test");
  }
  {
    auto perms = Permissions();
    auto user1 = User("test", "pw", perms);
    auto user2 = User("Test", "pw", perms);
    ASSERT_EQ(user1, user2);
    ASSERT_EQ(user1.username(), user2.username());
    ASSERT_EQ(user1.username(), "test");
    ASSERT_EQ(user2.username(), "test");
  }
  {
    auto role1 = Role("role");
    auto role2 = Role("Role");
    ASSERT_EQ(role1, role2);
    ASSERT_EQ(role1.rolename(), role2.rolename());
    ASSERT_EQ(role1.rolename(), "role");
    ASSERT_EQ(role2.rolename(), "role");
  }
  {
    auto perms = Permissions();
    auto role1 = Role("role", perms);
    auto role2 = Role("Role", perms);
    ASSERT_EQ(role1, role2);
    ASSERT_EQ(role1.rolename(), role2.rolename());
    ASSERT_EQ(role1.rolename(), "role");
    ASSERT_EQ(role2.rolename(), "role");
  }
}

TEST_F(AuthWithStorage, CaseInsensitivity) {
  // AddUser
  {
    auto user = auth.AddUser("Alice", "alice");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->username(), "alice");
    ASSERT_FALSE(auth.AddUser("alice"));
    ASSERT_FALSE(auth.AddUser("alicE"));
  }
  {
    auto user = auth.AddUser("BoB", "bob");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->username(), "bob");
    ASSERT_FALSE(auth.AddUser("bob"));
    ASSERT_FALSE(auth.AddUser("bOb"));
  }

  // Authenticate
  {
    auto user = auth.Authenticate("alice", "alice");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->username(), "alice");
  }
  {
    auto user = auth.Authenticate("alICe", "alice");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->username(), "alice");
  }

  // GetUser
  {
    auto user = auth.GetUser("alice");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->username(), "alice");
  }
  {
    auto user = auth.GetUser("aLicE");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->username(), "alice");
  }
  ASSERT_FALSE(auth.GetUser("carol"));

  // RemoveUser
  {
    auto user = auth.AddUser("caRol", "carol");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->username(), "carol");
    ASSERT_TRUE(auth.RemoveUser("cAROl"));
    ASSERT_FALSE(auth.RemoveUser("carol"));
    ASSERT_FALSE(auth.GetUser("CAROL"));
  }

  // AllUsers
  {
    auto users = auth.AllUsers();
    ASSERT_EQ(users.size(), 2);
    std::sort(users.begin(), users.end(), [](const auto &a, const auto &b) { return a.username() < b.username(); });
    ASSERT_EQ(users[0].username(), "alice");
    ASSERT_EQ(users[1].username(), "bob");
  }

  // AddRole
  {
    auto role = auth.AddRole("Moderator");
    ASSERT_TRUE(role);
    ASSERT_EQ(role->rolename(), "moderator");
    ASSERT_FALSE(auth.AddRole("moderator"));
    ASSERT_FALSE(auth.AddRole("MODERATOR"));
  }
  {
    auto role = auth.AddRole("adMIN");
    ASSERT_TRUE(role);
    ASSERT_EQ(role->rolename(), "admin");
    ASSERT_FALSE(auth.AddRole("Admin"));
    ASSERT_FALSE(auth.AddRole("ADMIn"));
  }
  ASSERT_FALSE(auth.AddRole("ALICE"));
  ASSERT_FALSE(auth.AddUser("ModeRAtor"));

  // GetRole
  {
    auto role = auth.GetRole("moderator");
    ASSERT_TRUE(role);
    ASSERT_EQ(role->rolename(), "moderator");
  }
  {
    auto role = auth.GetRole("MoDERATOR");
    ASSERT_TRUE(role);
    ASSERT_EQ(role->rolename(), "moderator");
  }
  ASSERT_FALSE(auth.GetRole("root"));

  // RemoveRole
  {
    auto role = auth.AddRole("RooT");
    ASSERT_TRUE(role);
    ASSERT_EQ(role->rolename(), "root");
    ASSERT_TRUE(auth.RemoveRole("rOOt"));
    ASSERT_FALSE(auth.RemoveRole("RoOt"));
    ASSERT_FALSE(auth.GetRole("RoOt"));
  }

  // AllRoles
  {
    auto roles = auth.AllRoles();
    ASSERT_EQ(roles.size(), 2);
    std::sort(roles.begin(), roles.end(), [](const auto &a, const auto &b) { return a.rolename() < b.rolename(); });
    ASSERT_EQ(roles[0].rolename(), "admin");
    ASSERT_EQ(roles[1].rolename(), "moderator");
  }

  // SaveRole
  {
    auto role = auth.GetRole("MODErator");
    ASSERT_TRUE(role);
    ASSERT_EQ(role->rolename(), "moderator");
    role->permissions().Grant(auth::Permission::MATCH);
    auth.SaveRole(*role);
  }
  {
    auto role = auth.GetRole("modeRATOR");
    ASSERT_TRUE(role);
    ASSERT_EQ(role->rolename(), "moderator");
    ASSERT_EQ(role->permissions().Has(auth::Permission::MATCH), auth::PermissionLevel::GRANT);
  }

  // SaveUser
  {
    auto user = auth.GetUser("aLice");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->username(), "alice");
    auto role = auth.GetRole("moderAtor");
    ASSERT_TRUE(role);
    ASSERT_EQ(role->rolename(), "moderator");
    user->SetRole(*role);
    auth.SaveUser(*user);
  }
  {
    auto user = auth.GetUser("aLIce");
    ASSERT_TRUE(user);
    ASSERT_EQ(user->username(), "alice");
    const auto *role = user->role();
    ASSERT_NE(role, nullptr);
    ASSERT_EQ(role->rolename(), "moderator");
  }

  // AllUsersForRole
  {
    auto carol = auth.AddUser("caROl");
    ASSERT_TRUE(carol);
    ASSERT_EQ(carol->username(), "carol");
    auto dave = auth.AddUser("daVe");
    ASSERT_TRUE(dave);
    ASSERT_EQ(dave->username(), "dave");
    auto admin = auth.GetRole("aDMin");
    ASSERT_TRUE(admin);
    ASSERT_EQ(admin->rolename(), "admin");
    carol->SetRole(*admin);
    auth.SaveUser(*carol);
    dave->SetRole(*admin);
    auth.SaveUser(*dave);
  }
  {
    auto users = auth.AllUsersForRole("modeRAtoR");
    ASSERT_EQ(users.size(), 1);
    ASSERT_EQ(users[0].username(), "alice");
  }
  {
    auto users = auth.AllUsersForRole("AdmiN");
    ASSERT_EQ(users.size(), 2);
    std::sort(users.begin(), users.end(), [](const auto &a, const auto &b) { return a.username() < b.username(); });
    ASSERT_EQ(users[0].username(), "carol");
    ASSERT_EQ(users[1].username(), "dave");
  }
}

TEST(AuthWithoutStorage, Crypto) {
  auto hash = EncryptPassword("hello");
  ASSERT_TRUE(VerifyPassword("hello", hash));
  ASSERT_FALSE(VerifyPassword("hello1", hash));
}