// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROMEOS_CRYPTOHOME_CRYPTOHOME_PARAMETERS_H_
#define CHROMEOS_CRYPTOHOME_CRYPTOHOME_PARAMETERS_H_

#include <stdint.h>

#include <memory>
#include <string>
#include <vector>

#include "base/containers/hash_tables.h"
#include "chromeos/chromeos_export.h"

class AccountId;

namespace cryptohome {

enum AuthKeyPrivileges {
  PRIV_MOUNT = 1 << 0,              // Can mount with this key.
  PRIV_ADD = 1 << 1,                // Can add new keys.
  PRIV_REMOVE = 1 << 2,             // Can remove other keys.
  PRIV_MIGRATE = 1 << 3,            // Destroy all keys and replace with new.
  PRIV_AUTHORIZED_UPDATE = 1 << 4,  // Key can be updated in place.
  PRIV_DEFAULT = PRIV_MOUNT | PRIV_ADD | PRIV_REMOVE | PRIV_MIGRATE
};

// Identification of the user calling cryptohome method.
class CHROMEOS_EXPORT Identification {
 public:
  Identification();

  explicit Identification(const AccountId& account_id);

  bool operator==(const Identification& other) const;

  // This method should be used for migration purpose only.
  static Identification FromString(const std::string& id);

  // Look up known user and return its AccountId.
  AccountId GetAccountId() const;

  const std::string& id() const { return id_; }

  bool operator<(const Identification& right) const;

 private:
  explicit Identification(const std::string&);

  std::string id_;
};

// Definition of the key (e.g. password) for the cryptohome.
// It contains authorization data along with extra parameters like permissions
// associated with this key.
struct CHROMEOS_EXPORT KeyDefinition {
  enum Type {
    TYPE_PASSWORD = 0
  };

  struct AuthorizationData {
    enum Type {
      TYPE_HMACSHA256 = 0,
      TYPE_AES256CBC_HMACSHA256
    };

    struct Secret {
      Secret();
      Secret(bool encrypt,
             bool sign,
             const std::string& symmetric_key,
             const std::string& public_key,
             bool wrapped);

      bool operator==(const Secret& other) const;

      bool encrypt;
      bool sign;
      std::string symmetric_key;
      std::string public_key;
      bool wrapped;
    };

    AuthorizationData();
    AuthorizationData(bool encrypt,
                      bool sign,
                      const std::string& symmetric_key);
    AuthorizationData(const AuthorizationData& other);
    ~AuthorizationData();

    bool operator==(const AuthorizationData& other) const;

    Type type;
    std::vector<Secret> secrets;
  };

  // This struct holds metadata that will be stored alongside the key. Each
  // |ProviderData| entry must have a |name| and may hold either a |number| or a
  // sequence of |bytes|. The metadata is entirely opaque to cryptohome. It is
  // stored with the key and returned when requested but is never interpreted by
  // cryptohome in any way. The metadata can be used to store information such
  // as the hashing algorithm and the salt used to create the key.
  struct ProviderData {
    ProviderData();
    explicit ProviderData(const std::string& name);
    explicit ProviderData(const ProviderData& other);
    ProviderData(const std::string& name, int64_t number);
    ProviderData(const std::string& name, const std::string& bytes);
    void operator=(const ProviderData& other);
    ~ProviderData();

    bool operator==(const ProviderData& other) const;

    std::string name;
    std::unique_ptr<int64_t> number;
    std::unique_ptr<std::string> bytes;
  };

  KeyDefinition();
  KeyDefinition(const std::string& secret,
                const std::string& label,
                int privileges);
  KeyDefinition(const KeyDefinition& other);
  ~KeyDefinition();

  bool operator==(const KeyDefinition& other) const;

  Type type;
  std::string label;
  // Privileges associated with key. Combination of |AuthKeyPrivileges| values.
  int privileges;
  int revision;
  std::string secret;

  std::vector<AuthorizationData> authorization_data;
  std::vector<ProviderData> provider_data;
};

// Authorization attempt data for user.
struct CHROMEOS_EXPORT Authorization {
  Authorization(const std::string& key, const std::string& label);
  explicit Authorization(const KeyDefinition& key);

  bool operator==(const Authorization& other) const;

  std::string key;
  std::string label;
};

// Parameters for Mount call.
class CHROMEOS_EXPORT MountParameters {
 public:
  explicit MountParameters(bool ephemeral);
  MountParameters(const MountParameters& other);
  ~MountParameters();

  bool operator==(const MountParameters& other) const;

  // If |true|, the mounted home dir will be backed by tmpfs. If |false|, the
  // ephemeral users policy decides whether tmpfs or an encrypted directory is
  // used as the backend.
  bool ephemeral;

  // If not empty, home dir will be created with these keys if it exist.
  std::vector<KeyDefinition> create_keys;
};

// This function returns true if cryptohome of |account_id| is migrated to
// accountId-based identifier (AccountId::GetAccountIdKey()).
bool GetGaiaIdMigrationStatus(const AccountId& account_id);

// This function marks |account_id| cryptohome migrated to accountId-based
// identifier (AccountId::GetAccountIdKey()).
void SetGaiaIdMigrationStatusDone(const AccountId& account_id);

}  // namespace cryptohome

namespace BASE_HASH_NAMESPACE {

// Implement hashing of cryptohome::Identification, so it can be used as a key
// in STL containers.
template <>
struct hash<cryptohome::Identification> {
  std::size_t operator()(const cryptohome::Identification& cryptohome_id) const;
};

}  // namespace BASE_HASH_NAMESPACE

#endif  // CHROMEOS_CRYPTOHOME_CRYPTOHOME_PARAMETERS_H_