redfish-core/include/privileges.hpp

#ifndef THIRD_PARTY_GBMCWEB_REDFISH_CORE_INCLUDE_PRIVILEGES_H_
#define THIRD_PARTY_GBMCWEB_REDFISH_CORE_INCLUDE_PRIVILEGES_H_

/*
// Copyright (c) 2018 Intel Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
*/
#pragma once

#include <array>
#include <bitset>
#include <cstddef>
#include <cstdint>
#include <initializer_list>
#include <string>
#include <string_view>
#include <vector>

#include "boost/beast/http/verb.hpp"  // NOLINT
#include "boost/container/flat_map.hpp"  // NOLINT
#include "boost/container/vector.hpp"  // NOLINT
#include "boost/move/algo/move.hpp"  // NOLINT
#include "logging.hpp"

// IWYU pragma: no_include <stddef.h>

namespace redfish {

enum class PrivilegeType : std::uint8_t { BASE, OEM };

/** @brief A fixed array of compile time privileges  */
constexpr std::array<const char*, 5> basePrivileges{
    "Login", "ConfigureManager", "ConfigureComponents", "ConfigureSelf",
    "ConfigureUsers"};

constexpr const size_t basePrivilegeCount = basePrivileges.size();

/** @brief Max number of privileges per type  */
constexpr const size_t maxPrivilegeCount = 32;

/** @brief A vector of all privilege names and their indexes */
static const std::array<std::string, maxPrivilegeCount> privilegeNames{ // NOLINT
    "Login", "ConfigureManager", "ConfigureComponents", "ConfigureSelf",
    "ConfigureUsers"};

/**
 * @brief Redfish privileges
 *
 *        This implements a set of Redfish privileges.  These directly represent
 *        user privileges and help represent entity privileges.
 *
 *        Each incoming Connection requires a comparison between privileges held
 *        by the user issuing a request and the target entity's privileges.
 *
 *        To ensure best runtime performance of this comparison, privileges
 *        are represented as bitsets. Each bit in the bitset corresponds to a
 *        unique privilege name.
 *
 *        A bit is set if the privilege is required (entity domain) or granted
 *        (user domain) and false otherwise.
 *
 */
class Privileges {
 public:
  /**
   * @brief Constructs object without any privileges active
   *
   */
  Privileges() = default;

  /**
   * @brief Constructs object with given privileges active
   *
   * @param[in] privilegeList  List of privileges to be activated
   *
   */
  Privileges(std::initializer_list<const char*> privilegeList) {
    for (const char* privilege : privilegeList) {
      if (!setSinglePrivilege(privilege)) {
        BMCWEB_LOG_CRITICAL << "Unable to set privilege " << privilege
                            << "in constructor";
      }
    }
  }

  /**
   * @brief Sets given privilege in the bitset
   *
   * @param[in] privilege  Privilege to be set
   *
   * @return               None
   *
   */
  bool setSinglePrivilege(std::string_view privilege) {
    for (size_t search_index = 0; search_index < privilegeNames.size();
         search_index++) {
      if (privilege == privilegeNames[search_index]) {
        privilegeBitset.set(search_index);
        return true;
      }
    }

    return false;
  }

  /**
   * @brief Resets the given privilege in the bitset
   *
   * @param[in] privilege  Privilege to be reset
   *
   * @return               None
   *
   */
  bool resetSinglePrivilege(const char* privilege) {
    for (size_t search_index = 0; search_index < privilegeNames.size();
         search_index++) {
      if (privilege == privilegeNames[search_index]) {
        privilegeBitset.reset(search_index);
        return true;
      }
    }
    return false;
  }

  /**
   * @brief Retrieves names of all active privileges for a given type
   *
   * @param[in] type    Base or OEM
   *
   * @return            Vector of active privileges.  Pointers are valid until
   * the setSinglePrivilege is called, or the Privilege structure is destroyed
   *
   */
  std::vector<std::string> getActivePrivilegeNames(
      const PrivilegeType type) const {
    std::vector<std::string> active_privileges;

    size_t search_index = 0;
    size_t end_index = basePrivilegeCount;
    if (type == PrivilegeType::OEM) {
      search_index = basePrivilegeCount;
      end_index = privilegeNames.size();
    }

    for (; search_index < end_index; search_index++) {
      if (privilegeBitset.test(search_index)) {
        active_privileges.push_back(privilegeNames[search_index]);
      }
    }

    return active_privileges;
  }

  /**
   * @brief Determines if this Privilege set is a superset of the given
   * privilege set
   *
   * @param[in] privilege  Privilege to be checked
   *
   * @return               None
   *
   */
  bool isSupersetOf(const Privileges& p) const {
    return (privilegeBitset & p.privilegeBitset) == p.privilegeBitset;
  }

  /**
   * @brief Returns the intersection of two Privilege sets.
   *
   * @param[in] privilege  Privilege set to intersect with.
   *
   * @return               The new Privilege set.
   *
   */
  Privileges intersection(const Privileges& p) const {
    return Privileges{privilegeBitset & p.privilegeBitset};
  }

 private:
  explicit Privileges(const std::bitset<maxPrivilegeCount>& p)
      : privilegeBitset{p} {}
  std::bitset<maxPrivilegeCount> privilegeBitset = 0;  // NOLINT
};

inline const Privileges& getUserPrivileges(const std::string& userRole) {
  // Redfish privilege : Administrator
  if (userRole == "priv-admin") {
    static Privileges admin{"Login", "ConfigureManager", "ConfigureSelf",
                            "ConfigureUsers", "ConfigureComponents"};
    return admin;
  }
  if (userRole == "priv-operator") {
    // Redfish privilege : Operator
    static Privileges op{"Login", "ConfigureSelf", "ConfigureComponents"};
    return op;
  }
  if (userRole == "priv-user") {
    // Redfish privilege : Readonly
    static Privileges read_only{"Login", "ConfigureSelf"};
    return read_only;
  }
  // Redfish privilege : NoAccess
  static Privileges noaccess;
  return noaccess;
}

/**
 * @brief The OperationMap represents the privileges required for a
 * single entity (URI).  It maps from the allowable verbs to the
 * privileges required to use that operation.
 *
 * This represents the Redfish "Privilege AND and OR syntax" as given
 * in the spec and shown in the Privilege Registry.  This does not
 * implement any Redfish property overrides, subordinate overrides, or
 * resource URI overrides.  This does not implement the limitation of
 * the ConfigureSelf privilege to operate only on your own account or
 * session.
 **/
using OperationMap = boost::container::flat_map<boost::beast::http::verb,
                                                std::vector<Privileges>>;

/* @brief Checks if user is allowed to call an operation
 *
 * @param[in] operationPrivilegesRequired   Privileges required
 * @param[in] userPrivileges                Privileges the user has
 *
 * @return                 True if operation is allowed, false otherwise
 */
inline bool isOperationAllowedWithPrivileges(
    const std::vector<Privileges>& operationPrivilegesRequired,
    const Privileges& userPrivileges) {
  // If there are no privileges assigned, there are no privileges required
  if (operationPrivilegesRequired.empty()) {
    return true;
  }
  for (const auto& required_privileges :  // NOLINT
       operationPrivilegesRequired) {
    BMCWEB_LOG_DEBUG << "Checking operation privileges...";
    if (userPrivileges.isSupersetOf(required_privileges)) {
      BMCWEB_LOG_DEBUG << "...success";
      return true;
    }
  }
  return false;
}

/**
 * @brief Checks if given privileges allow to call an HTTP method
 *
 * @param[in] method       HTTP method
 * @param[in] user         Privileges
 *
 * @return                 True if method allowed, false otherwise
 *
 */
inline bool isMethodAllowedWithPrivileges(const boost::beast::http::verb method,
                                          const OperationMap& operationMap,
                                          const Privileges& userPrivileges) {
  const auto it = operationMap.find(method);
  if (it == operationMap.end()) {
    return false;
  }

  return isOperationAllowedWithPrivileges(it->second, userPrivileges);
}

}  // namespace redfish

#endif  // THIRD_PARTY_GBMCWEB_REDFISH_CORE_INCLUDE_PRIVILEGES_H_