// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab ft=cpp

#include <array>
#include <string>

#include "rgw_common.h"
#include "rgw_auth.h"
#include "rgw_quota.h"
#include "rgw_user.h"
#include "rgw_http_client.h"
#include "rgw_keystone.h"
#include "rgw_sal.h"

#include "include/str_list.h"

#define dout_context g_ceph_context
#define dout_subsys ceph_subsys_rgw


namespace rgw {
namespace auth {

std::unique_ptr<rgw::auth::Identity>
transform_old_authinfo(CephContext* const cct,
                       const rgw_user& auth_id,
                       const int perm_mask,
                       const bool is_admin,
                       const uint32_t type)
{
  /* This class is not intended for public use. Should be removed altogether
   * with this function after moving all our APIs to the new authentication
   * infrastructure. */
  class DummyIdentityApplier : public rgw::auth::Identity {
    CephContext* const cct;

    /* For this particular case it's OK to use rgw_user structure to convey
     * the identity info as this was the policy for doing that before the
     * new auth. */
    const rgw_user id;
    const int perm_mask;
    const bool is_admin;
    const uint32_t type;
  public:
    DummyIdentityApplier(CephContext* const cct,
                         const rgw_user& auth_id,
                         const int perm_mask,
                         const bool is_admin,
                         const uint32_t type)
      : cct(cct),
        id(auth_id),
        perm_mask(perm_mask),
        is_admin(is_admin),
        type(type) {
    }

    uint32_t get_perms_from_aclspec(const DoutPrefixProvider* dpp, const aclspec_t& aclspec) const override {
      return rgw_perms_from_aclspec_default_strategy(id, aclspec);
    }

    bool is_admin_of(const rgw_user& acct_id) const override {
      return is_admin;
    }

    bool is_owner_of(const rgw_user& acct_id) const override {
      return id == acct_id;
    }

    bool is_identity(const idset_t& ids) const override {
      for (auto& p : ids) {
	if (p.is_wildcard()) {
	  return true;
	} else if (p.is_tenant() && p.get_tenant() == id.tenant) {
	  return true;
	} else if (p.is_user() &&
		   (p.get_tenant() == id.tenant) &&
		   (p.get_id() == id.id)) {
	  return true;
	}
      }
      return false;
    }

    uint32_t get_perm_mask() const override {
      return perm_mask;
    }

    uint32_t get_identity_type() const override {
      return type;
    }

    string get_acct_name() const override {
      return {};
    }

    string get_subuser() const override {
      return {};
    }

    void to_str(std::ostream& out) const override {
      out << "RGWDummyIdentityApplier(auth_id=" << id
          << ", perm_mask=" << perm_mask
          << ", is_admin=" << is_admin << ")";
    }
  };

  return std::unique_ptr<rgw::auth::Identity>(
        new DummyIdentityApplier(cct,
                                 auth_id,
                                 perm_mask,
                                 is_admin,
                                 type));
}

std::unique_ptr<rgw::auth::Identity>
transform_old_authinfo(const req_state* const s)
{
  return transform_old_authinfo(s->cct,
                                s->user->get_id(),
                                s->perm_mask,
  /* System user has admin permissions by default - it's supposed to pass
   * through any security check. */
                                s->system_request,
                                s->user->get_type());
}

} /* namespace auth */
} /* namespace rgw */


uint32_t rgw_perms_from_aclspec_default_strategy(
  const rgw_user& uid,
  const rgw::auth::Identity::aclspec_t& aclspec)
{
  dout(5) << "Searching permissions for uid=" << uid <<  dendl;

  const auto iter = aclspec.find(uid.to_str());
  if (std::end(aclspec) != iter) {
    dout(5) << "Found permission: " << iter->second << dendl;
    return iter->second;
  }

  dout(5) << "Permissions for user not found" << dendl;
  return 0;
}


static inline const std::string make_spec_item(const std::string& tenant,
                                               const std::string& id)
{
  return tenant + ":" + id;
}


static inline std::pair<bool, rgw::auth::Engine::result_t>
strategy_handle_rejected(rgw::auth::Engine::result_t&& engine_result,
                         const rgw::auth::Strategy::Control policy,
                         rgw::auth::Engine::result_t&& strategy_result)
{
  using Control = rgw::auth::Strategy::Control;
  switch (policy) {
    case Control::REQUISITE:
      /* Don't try next. */
      return std::make_pair(false, std::move(engine_result));

    case Control::SUFFICIENT:
      /* Don't try next. */
      return std::make_pair(false, std::move(engine_result));

    case Control::FALLBACK:
      /* Don't try next. */
      return std::make_pair(false, std::move(strategy_result));

    default:
      /* Huh, memory corruption? */
      ceph_abort();
  }
}

static inline std::pair<bool, rgw::auth::Engine::result_t>
strategy_handle_denied(rgw::auth::Engine::result_t&& engine_result,
                       const rgw::auth::Strategy::Control policy,
                       rgw::auth::Engine::result_t&& strategy_result)
{
  using Control = rgw::auth::Strategy::Control;
  switch (policy) {
    case Control::REQUISITE:
      /* Don't try next. */
      return std::make_pair(false, std::move(engine_result));

    case Control::SUFFICIENT:
      /* Just try next. */
      return std::make_pair(true, std::move(engine_result));

    case Control::FALLBACK:
      return std::make_pair(true, std::move(strategy_result));

    default:
      /* Huh, memory corruption? */
      ceph_abort();
  }
}

static inline std::pair<bool, rgw::auth::Engine::result_t>
strategy_handle_granted(rgw::auth::Engine::result_t&& engine_result,
                        const rgw::auth::Strategy::Control policy,
                        rgw::auth::Engine::result_t&& strategy_result)
{
  using Control = rgw::auth::Strategy::Control;
  switch (policy) {
    case Control::REQUISITE:
      /* Try next. */
      return std::make_pair(true, std::move(engine_result));

    case Control::SUFFICIENT:
      /* Don't try next. */
      return std::make_pair(false, std::move(engine_result));

    case Control::FALLBACK:
      /* Don't try next. */
      return std::make_pair(false, std::move(engine_result));

    default:
      /* Huh, memory corruption? */
      ceph_abort();
  }
}

rgw::auth::Engine::result_t
rgw::auth::Strategy::authenticate(const DoutPrefixProvider* dpp, const req_state* const s) const
{
  result_t strategy_result = result_t::deny();

  for (const stack_item_t& kv : auth_stack) {
    const rgw::auth::Engine& engine = kv.first;
    const auto& policy = kv.second;

    ldpp_dout(dpp, 20) << get_name() << ": trying " << engine.get_name() << dendl;

    result_t engine_result = result_t::deny();
    try {
      engine_result = engine.authenticate(dpp, s);
    } catch (const int err) {
      engine_result = result_t::deny(err);
    }

    bool try_next = true;
    switch (engine_result.get_status()) {
      case result_t::Status::REJECTED: {
        ldpp_dout(dpp, 20) << engine.get_name() << " rejected with reason="
                 << engine_result.get_reason() << dendl;

        std::tie(try_next, strategy_result) = \
          strategy_handle_rejected(std::move(engine_result), policy,
                                   std::move(strategy_result));
        break;
      }
      case result_t::Status::DENIED: {
        ldpp_dout(dpp, 20) << engine.get_name() << " denied with reason="
                 << engine_result.get_reason() << dendl;

        std::tie(try_next, strategy_result) = \
          strategy_handle_denied(std::move(engine_result), policy,
                                 std::move(strategy_result));
        break;
      }
      case result_t::Status::GRANTED: {
        ldpp_dout(dpp, 20) << engine.get_name() << " granted access" << dendl;

        std::tie(try_next, strategy_result) = \
          strategy_handle_granted(std::move(engine_result), policy,
                                  std::move(strategy_result));
        break;
      }
      default: {
        ceph_abort();
      }
    }

    if (! try_next) {
      break;
    }
  }

  return strategy_result;
}

int
rgw::auth::Strategy::apply(const DoutPrefixProvider *dpp, const rgw::auth::Strategy& auth_strategy,
                           req_state* const s) noexcept
{
  try {
    auto result = auth_strategy.authenticate(dpp, s);
    if (result.get_status() != decltype(result)::Status::GRANTED) {
      /* Access denied is acknowledged by returning a std::unique_ptr with
       * nullptr inside. */
      ldpp_dout(dpp, 5) << "Failed the auth strategy, reason="
                       << result.get_reason() << dendl;
      return result.get_reason();
    }

    try {
      rgw::auth::IdentityApplier::aplptr_t applier = result.get_applier();
      rgw::auth::Completer::cmplptr_t completer = result.get_completer();

      /* Account used by a given RGWOp is decoupled from identity employed
       * in the authorization phase (RGWOp::verify_permissions). */
      applier->load_acct_info(dpp, s->user->get_info());
      s->perm_mask = applier->get_perm_mask();

      /* This is the single place where we pass req_state as a pointer
       * to non-const and thus its modification is allowed. In the time
       * of writing only RGWTempURLEngine needed that feature. */
      applier->modify_request_state(dpp, s);
      if (completer) {
        completer->modify_request_state(dpp, s);
      }

      s->auth.identity = std::move(applier);
      s->auth.completer = std::move(completer);

      return 0;
    } catch (const int err) {
      ldpp_dout(dpp, 5) << "applier throwed err=" << err << dendl;
      return err;
    }
  } catch (const int err) {
    ldpp_dout(dpp, 5) << "auth engine throwed err=" << err << dendl;
    return err;
  }

  /* We never should be here. */
  return -EPERM;
}

void
rgw::auth::Strategy::add_engine(const Control ctrl_flag,
                                const Engine& engine) noexcept
{
  auth_stack.push_back(std::make_pair(std::cref(engine), ctrl_flag));
}

void rgw::auth::WebIdentityApplier::to_str(std::ostream& out) const
{
  out << "rgw::auth::WebIdentityApplier(sub =" << token_claims.sub
      << ", user_name=" << token_claims.user_name
      << ", aud =" << token_claims.aud
      << ", provider_id =" << token_claims.iss << ")";
}

string rgw::auth::WebIdentityApplier::get_idp_url() const
{
  string idp_url = token_claims.iss;
  idp_url = url_remove_prefix(idp_url);
  return idp_url;
}

void rgw::auth::WebIdentityApplier::modify_request_state(const DoutPrefixProvider *dpp, req_state* s) const
{
  s->info.args.append("sub", token_claims.sub);
  s->info.args.append("aud", token_claims.aud);
  s->info.args.append("provider_id", token_claims.iss);
  s->info.args.append("client_id", token_claims.client_id);

  string idp_url = get_idp_url();
  string condition = idp_url + ":app_id";

  s->env.emplace(condition, token_claims.aud);

  condition.clear();
  condition = idp_url + ":sub";
  s->env.emplace(condition, token_claims.sub);
}

bool rgw::auth::WebIdentityApplier::is_identity(const idset_t& ids) const
{
  if (ids.size() > 1) {
    return false;
  }

  for (auto id : ids) {
    string idp_url = get_idp_url();
    if (id.is_oidc_provider() && id.get_idp_url() == idp_url) {
      return true;
    }
  }
    return false;
}

/* rgw::auth::RemoteAuthApplier */
uint32_t rgw::auth::RemoteApplier::get_perms_from_aclspec(const DoutPrefixProvider* dpp, const aclspec_t& aclspec) const
{
  uint32_t perm = 0;

  /* For backward compatibility with ACLOwner. */
  perm |= rgw_perms_from_aclspec_default_strategy(info.acct_user,
                                                  aclspec);

  /* We also need to cover cases where rgw_keystone_implicit_tenants
   * was enabled. */
  if (info.acct_user.tenant.empty()) {
    const rgw_user tenanted_acct_user(info.acct_user.id, info.acct_user.id);

    perm |= rgw_perms_from_aclspec_default_strategy(tenanted_acct_user,
                                                    aclspec);
  }

  /* Now it's a time for invoking additional strategy that was supplied by
   * a specific auth engine. */
  if (extra_acl_strategy) {
    perm |= extra_acl_strategy(aclspec);
  }

  ldpp_dout(dpp, 20) << "from ACL got perm=" << perm << dendl;
  return perm;
}

bool rgw::auth::RemoteApplier::is_admin_of(const rgw_user& uid) const
{
  return info.is_admin;
}

bool rgw::auth::RemoteApplier::is_owner_of(const rgw_user& uid) const
{
  if (info.acct_user.tenant.empty()) {
    const rgw_user tenanted_acct_user(info.acct_user.id, info.acct_user.id);

    if (tenanted_acct_user == uid) {
      return true;
    }
  }

  return info.acct_user == uid;
}

bool rgw::auth::RemoteApplier::is_identity(const idset_t& ids) const {
  for (auto& id : ids) {
    if (id.is_wildcard()) {
      return true;

      // We also need to cover cases where rgw_keystone_implicit_tenants
      // was enabled. */
    } else if (id.is_tenant() &&
	       (info.acct_user.tenant.empty() ?
		info.acct_user.id :
		info.acct_user.tenant) == id.get_tenant()) {
      return true;
    } else if (id.is_user() &&
	       info.acct_user.id == id.get_id() &&
	       (info.acct_user.tenant.empty() ?
		info.acct_user.id :
		info.acct_user.tenant) == id.get_tenant()) {
      return true;
    }
  }
  return false;
}

void rgw::auth::RemoteApplier::to_str(std::ostream& out) const
{
  out << "rgw::auth::RemoteApplier(acct_user=" << info.acct_user
      << ", acct_name=" << info.acct_name
      << ", perm_mask=" << info.perm_mask
      << ", is_admin=" << info.is_admin << ")";
}

void rgw::auth::ImplicitTenants::recompute_value(const ConfigProxy& c)
{
  std::string s = c.get_val<std::string>("rgw_keystone_implicit_tenants");
  int v = 0;
  if (boost::iequals(s, "both")
    || boost::iequals(s, "true")
    || boost::iequals(s, "1")) {
    v = IMPLICIT_TENANTS_S3|IMPLICIT_TENANTS_SWIFT;
  } else if (boost::iequals(s, "0")
    || boost::iequals(s, "none")
    || boost::iequals(s, "false")) {
    v = 0;
  } else if (boost::iequals(s, "s3")) {
    v = IMPLICIT_TENANTS_S3;
  } else if (boost::iequals(s, "swift")) {
    v = IMPLICIT_TENANTS_SWIFT;
  } else {  /* "" (and anything else) */
    v = IMPLICIT_TENANTS_BAD;
    // assert(0);
  }
  saved = v;
}

const char **rgw::auth::ImplicitTenants::get_tracked_conf_keys() const
{
  static const char *keys[] = {
    "rgw_keystone_implicit_tenants",
  nullptr };
  return keys;
}

void rgw::auth::ImplicitTenants::handle_conf_change(const ConfigProxy& c,
	const std::set <std::string> &changed)
{
  if (changed.count("rgw_keystone_implicit_tenants")) {
    recompute_value(c);
  }
}

void rgw::auth::RemoteApplier::create_account(const DoutPrefixProvider* dpp,
                                              const rgw_user& acct_user,
                                              bool implicit_tenant,
                                              RGWUserInfo& user_info) const      /* out */
{
  rgw_user new_acct_user = acct_user;

  if (info.acct_type) {
    //ldap/keystone for s3 users
    user_info.type = info.acct_type;
  }

  /* An upper layer may enforce creating new accounts within their own
   * tenants. */
  if (new_acct_user.tenant.empty() && implicit_tenant) {
    new_acct_user.tenant = new_acct_user.id;
  }

  user_info.user_id = new_acct_user;
  user_info.display_name = info.acct_name;

  user_info.max_buckets =
    cct->_conf.get_val<int64_t>("rgw_user_max_buckets");
  rgw_apply_default_bucket_quota(user_info.bucket_quota, cct->_conf);
  rgw_apply_default_user_quota(user_info.user_quota, cct->_conf);

  int ret = ctl->user->store_info(user_info, null_yield,
                                  RGWUserCtl::PutParams().set_exclusive(true));
  if (ret < 0) {
    ldpp_dout(dpp, 0) << "ERROR: failed to store new user info: user="
                  << user_info.user_id << " ret=" << ret << dendl;
    throw ret;
  }
}

/* TODO(rzarzynski): we need to handle display_name changes. */
void rgw::auth::RemoteApplier::load_acct_info(const DoutPrefixProvider* dpp, RGWUserInfo& user_info) const      /* out */
{
  /* It's supposed that RGWRemoteAuthApplier tries to load account info
   * that belongs to the authenticated identity. Another policy may be
   * applied by using a RGWThirdPartyAccountAuthApplier decorator. */
  const rgw_user& acct_user = info.acct_user;
  auto implicit_value = implicit_tenant_context.get_value();
  bool implicit_tenant = implicit_value.implicit_tenants_for_(implicit_tenant_bit);
  bool split_mode = implicit_value.is_split_mode();

  /* Normally, empty "tenant" field of acct_user means the authenticated
   * identity has the legacy, global tenant. However, due to inclusion
   * of multi-tenancy, we got some special compatibility kludge for remote
   * backends like Keystone.
   * If the global tenant is the requested one, we try the same tenant as
   * the user name first. If that RGWUserInfo exists, we use it. This way,
   * migrated OpenStack users can get their namespaced containers and nobody's
   * the wiser.
   * If that fails, we look up in the requested (possibly empty) tenant.
   * If that fails too, we create the account within the global or separated
   * namespace depending on rgw_keystone_implicit_tenants.
   * For compatibility with previous versions of ceph, it is possible
   * to enable implicit_tenants for only s3 or only swift.
   * in this mode ("split_mode"), we must constrain the id lookups to
   * only use the identifier space that would be used if the id were
   * to be created. */

  if (split_mode && !implicit_tenant)
	;	/* suppress lookup for id used by "other" protocol */
  else if (acct_user.tenant.empty()) {
    const rgw_user tenanted_uid(acct_user.id, acct_user.id);

    if (ctl->user->get_info_by_uid(tenanted_uid, &user_info, null_yield) >= 0) {
      /* Succeeded. */
      return;
    }
  }

  if (split_mode && implicit_tenant)
	;	/* suppress lookup for id used by "other" protocol */
  else if (ctl->user->get_info_by_uid(acct_user, &user_info, null_yield) >= 0) {
      /* Succeeded. */
      return;
  }

  ldpp_dout(dpp, 0) << "NOTICE: couldn't map swift user " << acct_user << dendl;
  create_account(dpp, acct_user, implicit_tenant, user_info);

  /* Succeeded if we are here (create_account() hasn't throwed). */
}

/* rgw::auth::LocalApplier */
/* static declaration */
const std::string rgw::auth::LocalApplier::NO_SUBUSER;

uint32_t rgw::auth::LocalApplier::get_perms_from_aclspec(const DoutPrefixProvider* dpp, const aclspec_t& aclspec) const
{
  return rgw_perms_from_aclspec_default_strategy(user_info.user_id, aclspec);
}

bool rgw::auth::LocalApplier::is_admin_of(const rgw_user& uid) const
{
  return user_info.admin || user_info.system;
}

bool rgw::auth::LocalApplier::is_owner_of(const rgw_user& uid) const
{
  return uid == user_info.user_id;
}

bool rgw::auth::LocalApplier::is_identity(const idset_t& ids) const {
  for (auto& id : ids) {
    if (id.is_wildcard()) {
      return true;
    } else if (id.is_tenant() &&
	       id.get_tenant() == user_info.user_id.tenant) {
      return true;
    } else if (id.is_user() &&
	       (id.get_tenant() == user_info.user_id.tenant)) {
      if (id.get_id() == user_info.user_id.id) {
        return true;
      }
      std::string wildcard_subuser = user_info.user_id.id;
      wildcard_subuser.append(":*");
      if (wildcard_subuser == id.get_id()) {
        return true;
      } else if (subuser != NO_SUBUSER) {
        std::string user = user_info.user_id.id;
        user.append(":");
        user.append(subuser);
        if (user == id.get_id()) {
          return true;
        }
      }
    }
  }
  return false;
}

void rgw::auth::LocalApplier::to_str(std::ostream& out) const {
  out << "rgw::auth::LocalApplier(acct_user=" << user_info.user_id
      << ", acct_name=" << user_info.display_name
      << ", subuser=" << subuser
      << ", perm_mask=" << get_perm_mask()
      << ", is_admin=" << static_cast<bool>(user_info.admin) << ")";
}

uint32_t rgw::auth::LocalApplier::get_perm_mask(const std::string& subuser_name,
                                                const RGWUserInfo &uinfo) const
{
  if (! subuser_name.empty() && subuser_name != NO_SUBUSER) {
    const auto iter = uinfo.subusers.find(subuser_name);

    if (iter != std::end(uinfo.subusers)) {
      return iter->second.perm_mask;
    } else {
      /* Subuser specified but not found. */
      return RGW_PERM_NONE;
    }
  } else {
    /* Due to backward compatibility. */
    return RGW_PERM_FULL_CONTROL;
  }
}

void rgw::auth::LocalApplier::load_acct_info(const DoutPrefixProvider* dpp, RGWUserInfo& user_info) const /* out */
{
  /* Load the account that belongs to the authenticated identity. An extra call
   * to RADOS may be safely skipped in this case. */
  user_info = this->user_info;
}

void rgw::auth::RoleApplier::to_str(std::ostream& out) const {
  out << "rgw::auth::LocalApplier(role name =" << role.name;
  for (auto& policy: role.role_policies) {
    out << ", role policy =" << policy;
  }
  out << ", token policy =" << token_policy;
  out << ")";
}

bool rgw::auth::RoleApplier::is_identity(const idset_t& ids) const {
  for (auto& p : ids) {
    if (p.is_wildcard()) {
      return true;
    } else if (p.is_role()) {
      string name = p.get_id();
      string tenant = p.get_tenant();
      if (name == role.name && tenant == role.tenant) {
        return true;
      }
    } else if (p.is_assumed_role()) {
      string tenant = p.get_tenant();
      string role_session = role.name + "/" + role_session_name; //role/role-session
      if (role.tenant == tenant && role_session == p.get_role_session()) {
        return true;
      }
    } else {
      string id = p.get_id();
      if (user_id.id == id) {
        return true;
      }
    }
  }
  return false;
}

void rgw::auth::RoleApplier::load_acct_info(const DoutPrefixProvider* dpp, RGWUserInfo& user_info) const /* out */
{
  /* Load the user id */
  user_info.user_id = this->user_id;

  user_info.user_id.tenant = role.tenant;
}

void rgw::auth::RoleApplier::modify_request_state(const DoutPrefixProvider *dpp, req_state* s) const
{
  for (auto it: role.role_policies) {
    try {
      bufferlist bl = bufferlist::static_from_string(it);
      const rgw::IAM::Policy p(s->cct, role.tenant, bl);
      s->iam_user_policies.push_back(std::move(p));
    } catch (rgw::IAM::PolicyParseException& e) {
      //Control shouldn't reach here as the policy has already been
      //verified earlier
      ldpp_dout(dpp, 20) << "failed to parse role policy: " << e.what() << dendl;
    }
  }

  try {
    string policy = this->token_policy;
    bufferlist bl = bufferlist::static_from_string(policy);
    const rgw::IAM::Policy p(s->cct, role.tenant, bl);
    s->iam_user_policies.push_back(std::move(p));
  } catch (rgw::IAM::PolicyParseException& e) {
    //Control shouldn't reach here as the policy has already been
    //verified earlier
    ldpp_dout(dpp, 20) << "failed to parse token policy: " << e.what() << dendl;
  }

  string condition = "aws:userid";
  string value = role.id + ":" + role_session_name;
  s->env.emplace(condition, value);

  s->token_claims.emplace_back("sts");
  for (auto& it : token_claims) {
    s->token_claims.emplace_back(it);
  }
}

rgw::auth::Engine::result_t
rgw::auth::AnonymousEngine::authenticate(const DoutPrefixProvider* dpp, const req_state* const s) const
{
  if (! is_applicable(s)) {
    return result_t::deny(-EPERM);
  } else {
    RGWUserInfo user_info;
    rgw_get_anon_user(user_info);

    auto apl = \
      apl_factory->create_apl_local(cct, s, user_info,
                                    rgw::auth::LocalApplier::NO_SUBUSER,
                                    boost::none);
    return result_t::grant(std::move(apl));
  }
}
