// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"errors"
	"fmt"
	"maps"
	"path"
	"sort"
	"strings"
	"sync"
	"time"

	jsoniter "github.com/json-iterator/go"
	"github.com/minio/madmin-go/v3"
	"github.com/minio/minio-go/v7/pkg/set"
	"github.com/minio/minio/internal/auth"
	"github.com/minio/minio/internal/config"
	"github.com/minio/minio/internal/config/identity/openid"
	"github.com/minio/minio/internal/jwt"
	"github.com/pgsty/silo-pkg/v3/env"
	"github.com/pgsty/silo-pkg/v3/policy"
	"github.com/pgsty/silo-pkg/v3/sync/errgroup"
	"github.com/puzpuzpuz/xsync/v3"
	"golang.org/x/sync/singleflight"
)

const (
	// IAM configuration directory.
	iamConfigPrefix = minioConfigPrefix + "/iam"

	// IAM users directory.
	iamConfigUsersPrefix = iamConfigPrefix + "/users/"

	// IAM service accounts directory.
	iamConfigServiceAccountsPrefix = iamConfigPrefix + "/service-accounts/"

	// IAM groups directory.
	iamConfigGroupsPrefix = iamConfigPrefix + "/groups/"

	// IAM policies directory.
	iamConfigPoliciesPrefix = iamConfigPrefix + "/policies/"

	// IAM sts directory.
	iamConfigSTSPrefix = iamConfigPrefix + "/sts/"

	// IAM Policy DB prefixes.
	iamConfigPolicyDBPrefix                = iamConfigPrefix + "/policydb/"
	iamConfigPolicyDBUsersPrefix           = iamConfigPolicyDBPrefix + "users/"
	iamConfigPolicyDBSTSUsersPrefix        = iamConfigPolicyDBPrefix + "sts-users/"
	iamConfigPolicyDBServiceAccountsPrefix = iamConfigPolicyDBPrefix + "service-accounts/"
	iamConfigPolicyDBGroupsPrefix          = iamConfigPolicyDBPrefix + "groups/"

	// IAM identity file which captures identity credentials.
	iamIdentityFile = "identity.json"

	// IAM policy file which provides policies for each users.
	iamPolicyFile = "policy.json"

	// IAM group members file
	iamGroupMembersFile = "members.json"

	// IAM format file
	iamFormatFile = "format.json"

	iamFormatVersion1 = 1

	minServiceAccountExpiry time.Duration = 15 * time.Minute
	maxServiceAccountExpiry time.Duration = 365 * 24 * time.Hour
)

var errInvalidSvcAcctExpiration = errors.New("invalid service account expiration")

type iamFormat struct {
	Version int `json:"version"`
}

func newIAMFormatVersion1() iamFormat {
	return iamFormat{Version: iamFormatVersion1}
}

func getIAMFormatFilePath() string {
	return iamConfigPrefix + SlashSeparator + iamFormatFile
}

func getUserIdentityPath(user string, userType IAMUserType) string {
	var basePath string
	switch userType {
	case svcUser:
		basePath = iamConfigServiceAccountsPrefix
	case stsUser:
		basePath = iamConfigSTSPrefix
	default:
		basePath = iamConfigUsersPrefix
	}
	return pathJoin(basePath, user, iamIdentityFile)
}

func saveIAMFormat(ctx context.Context, store IAMStorageAPI) error {
	bootstrapTraceMsg("Load IAM format file")
	var iamFmt iamFormat
	path := getIAMFormatFilePath()
	if err := store.loadIAMConfig(ctx, &iamFmt, path); err != nil && !errors.Is(err, errConfigNotFound) {
		// if IAM format
		return err
	}

	if iamFmt.Version >= iamFormatVersion1 {
		// Nothing to do.
		return nil
	}

	bootstrapTraceMsg("Write IAM format file")
	// Save iam format to version 1.
	return store.saveIAMConfig(ctx, newIAMFormatVersion1(), path)
}

func getGroupInfoPath(group string) string {
	return pathJoin(iamConfigGroupsPrefix, group, iamGroupMembersFile)
}

func getPolicyDocPath(name string) string {
	return pathJoin(iamConfigPoliciesPrefix, name, iamPolicyFile)
}

func getMappedPolicyPath(name string, userType IAMUserType, isGroup bool) string {
	if isGroup {
		return pathJoin(iamConfigPolicyDBGroupsPrefix, name+".json")
	}
	switch userType {
	case svcUser:
		return pathJoin(iamConfigPolicyDBServiceAccountsPrefix, name+".json")
	case stsUser:
		return pathJoin(iamConfigPolicyDBSTSUsersPrefix, name+".json")
	default:
		return pathJoin(iamConfigPolicyDBUsersPrefix, name+".json")
	}
}

// UserIdentity represents a user's secret key and their status
type UserIdentity struct {
	Deleted       bool             `json:"deleted,omitempty"`
	RevokedBefore time.Time        `json:"revokedBefore,omitempty"`
	ExpiresAt     time.Time        `json:"expiresAt,omitempty"`
	Version       int              `json:"version"`
	Credentials   auth.Credentials `json:"credentials"`
	UpdatedAt     time.Time        `json:"updatedAt"`
}

func newUserIdentity(cred auth.Credentials) UserIdentity {
	return UserIdentity{Version: 1, Credentials: cred, UpdatedAt: UTCNow()}
}

// GroupInfo contains info about a group
type GroupInfo struct {
	RevokedBefore time.Time            `json:"revokedBefore,omitempty"`
	MemberGrants  map[string]time.Time `json:"memberGrants,omitempty"`
	Deleted       bool                 `json:"deleted,omitempty"`
	Version       int                  `json:"version"`
	Status        string               `json:"status"`
	Members       []string             `json:"members"`
	UpdatedAt     time.Time            `json:"updatedAt"`
}

func newGroupInfo(members []string) GroupInfo {
	return GroupInfo{Version: 1, Status: statusEnabled, Members: members, UpdatedAt: UTCNow()}
}

// MappedPolicy represents a policy name mapped to a user or group
type MappedPolicy struct {
	Deleted   bool      `json:"deleted,omitempty"`
	Version   int       `json:"version"`
	Policies  string    `json:"policy"`
	UpdatedAt time.Time `json:"updatedAt"`
}

// mappedPoliciesToMap copies the map of mapped policies to a regular map.
func mappedPoliciesToMap(m *xsync.MapOf[string, MappedPolicy]) map[string]MappedPolicy {
	policies := make(map[string]MappedPolicy, m.Size())
	m.Range(func(k string, v MappedPolicy) bool {
		policies[k] = v
		return true
	})
	return policies
}

// converts a mapped policy into a slice of distinct policies
func (mp MappedPolicy) toSlice() []string {
	var policies []string
	for policy := range strings.SplitSeq(mp.Policies, ",") {
		if strings.TrimSpace(policy) == "" {
			continue
		}
		policies = append(policies, policy)
	}
	return policies
}

func (mp MappedPolicy) policySet() set.StringSet {
	return set.CreateStringSet(mp.toSlice()...)
}

func newMappedPolicy(policy string) MappedPolicy {
	return MappedPolicy{Version: 1, Policies: policy, UpdatedAt: UTCNow()}
}

// PolicyDoc represents an IAM policy with some metadata.
type PolicyDoc struct {
	Deleted    bool `json:"deleted,omitempty"`
	Version    int  `json:",omitempty"`
	Policy     policy.Policy
	CreateDate time.Time
	UpdateDate time.Time
}

func newPolicyDoc(p policy.Policy) PolicyDoc {
	now := UTCNow().Round(time.Millisecond)
	return PolicyDoc{
		Version:    1,
		Policy:     p,
		CreateDate: now,
		UpdateDate: now,
	}
}

// defaultPolicyDoc - used to wrap a default policy as PolicyDoc.
func defaultPolicyDoc(p policy.Policy) PolicyDoc {
	return PolicyDoc{
		Version: 1,
		Policy:  p,
	}
}

func (d *PolicyDoc) update(p policy.Policy) {
	now := UTCNow().Round(time.Millisecond)
	d.UpdateDate = now
	if d.CreateDate.IsZero() {
		d.CreateDate = now
	}
	d.Policy = p
}

// parseJSON parses both the old and the new format for storing policy
// definitions.
//
// The on-disk format of policy definitions has changed (around early 12/2021)
// from policy.Policy to PolicyDoc. To avoid a migration, loading supports
// both the old and the new formats.
func (d *PolicyDoc) parseJSON(data []byte) error {
	json := jsoniter.ConfigCompatibleWithStandardLibrary
	var doc PolicyDoc
	err := json.Unmarshal(data, &doc)
	if err != nil {
		err2 := json.Unmarshal(data, &doc.Policy)
		if err2 != nil {
			// Just return the first error.
			return err
		}
		d.Policy = doc.Policy
		return nil
	}
	*d = doc
	return nil
}

// key options
type options struct {
	ttl int64 // expiry in seconds
}

type iamWatchEvent struct {
	isCreated bool // !isCreated implies a delete event.
	keyPath   string
}

// iamCache contains in-memory cache of IAM data.
type iamCache struct {
	updatedAt time.Time
	revisions *iamRevisionIndex

	// map of policy names to policy definitions
	iamPolicyDocsMap map[string]PolicyDoc

	// map of regular username to credentials
	iamUsersMap map[string]UserIdentity
	// map of regular username to policy names
	iamUserPolicyMap *xsync.MapOf[string, MappedPolicy]

	// STS accounts are loaded on demand and not via the periodic IAM reload.
	// map of STS access key to credentials
	iamSTSAccountsMap map[string]UserIdentity
	// map of STS access key to policy names
	iamSTSPolicyMap *xsync.MapOf[string, MappedPolicy]

	// map of group names to group info
	iamGroupsMap map[string]GroupInfo
	// map of user names to groups they are a member of
	iamUserGroupMemberships map[string]set.StringSet
	// map of group names to policy names
	iamGroupPolicyMap *xsync.MapOf[string, MappedPolicy]
}

func newIamCache() *iamCache {
	return &iamCache{
		iamPolicyDocsMap:        map[string]PolicyDoc{},
		iamUsersMap:             map[string]UserIdentity{},
		iamUserPolicyMap:        xsync.NewMapOf[string, MappedPolicy](),
		iamSTSAccountsMap:       map[string]UserIdentity{},
		iamSTSPolicyMap:         xsync.NewMapOf[string, MappedPolicy](),
		iamGroupsMap:            map[string]GroupInfo{},
		iamUserGroupMemberships: map[string]set.StringSet{},
		iamGroupPolicyMap:       xsync.NewMapOf[string, MappedPolicy](),
	}
}

// buildUserGroupMemberships - builds the memberships map. IMPORTANT:
// Assumes that c.Lock is held by caller.
func (c *iamCache) buildUserGroupMemberships() {
	for group, gi := range c.iamGroupsMap {
		c.updateGroupMembershipsMap(group, &gi)
	}
}

// updateGroupMembershipsMap - updates the memberships map for a
// group. IMPORTANT: Assumes c.Lock() is held by caller.
func (c *iamCache) updateGroupMembershipsMap(group string, gi *GroupInfo) {
	if gi == nil {
		return
	}
	for _, member := range gi.Members {
		if !c.groupMemberAllowed(member, gi.MemberGrants[member], gi.RevokedBefore) {
			continue
		}
		v := c.iamUserGroupMemberships[member]
		if v == nil {
			v = set.CreateStringSet(group)
		} else {
			v.Add(group)
		}
		c.iamUserGroupMemberships[member] = v
	}
}

// removeGroupFromMembershipsMap - removes the group from every member
// in the cache. IMPORTANT: Assumes c.Lock() is held by caller.
func (c *iamCache) removeGroupFromMembershipsMap(group string) {
	for member, groups := range c.iamUserGroupMemberships {
		if !groups.Contains(group) {
			continue
		}
		groups.Remove(group)
		c.iamUserGroupMemberships[member] = groups
	}
}

func (c *iamCache) policyDBGetGroups(store *IAMStoreSys, userPolicyPresent bool, groups ...string) ([]string, error) {
	var policies []string
	for _, group := range groups {
		if store.getUsersSysType() == MinIOUsersSysType {
			g, ok := c.iamGroupsMap[group]
			if !ok {
				continue
			}

			// Group is disabled, so we return no policy - this
			// ensures the request is denied.
			if g.Status == statusDisabled {
				continue
			}
		}

		policy, ok := c.cachedMappedPolicy(group, regUser, true)
		if !ok {
			continue
		}

		policies = append(policies, policy.toSlice()...)
	}

	found := len(policies) > 0
	if found {
		return policies, nil
	}

	if userPolicyPresent {
		// if user mapping present and no group policies found
		// rely on user policy for access, instead of fallback.
		return nil, nil
	}

	var mu sync.Mutex

	// no mappings found, fallback for all groups.
	g := errgroup.WithNErrs(len(groups)).WithConcurrency(10) // load like 10 groups at a time.

	for index := range groups {
		g.Go(func() error {
			err := store.loadMappedPolicy(context.TODO(), groups[index], regUser, true, c.iamGroupPolicyMap)
			if err != nil && !errors.Is(err, errNoSuchPolicy) {
				return err
			}
			if errors.Is(err, errNoSuchPolicy) {
				return nil
			}
			policy, _ := c.cachedMappedPolicy(groups[index], regUser, true)
			mu.Lock()
			policies = append(policies, policy.toSlice()...)
			mu.Unlock()
			return nil
		}, index)
	}

	err := errors.Join(g.Wait()...)
	return policies, err
}

// policyDBGet - lower-level helper; does not take locks.
//
// If a group is passed, it returns policies associated with the group.
//
// If a user is passed, it returns policies of the user along with any groups
// that the server knows the user is a member of.
//
// In LDAP users mode, the server does not store any group membership
// information in IAM (i.e sys.iam*Map) - this info is stored only in the STS
// generated credentials. Thus we skip looking up group memberships, user map,
// and group map and check the appropriate policy maps directly.
func (c *iamCache) policyDBGet(store *IAMStoreSys, name string, isGroup bool, policyPresent bool) ([]string, time.Time, error) {
	if isGroup {
		if store.getUsersSysType() == MinIOUsersSysType {
			g, ok := c.iamGroupsMap[name]
			if !ok {
				if err := store.loadGroup(context.Background(), name, c.iamGroupsMap); err != nil {
					return nil, time.Time{}, err
				}
				g, ok = c.iamGroupsMap[name]
				if !ok {
					return nil, time.Time{}, errNoSuchGroup
				}
			}

			// Group is disabled, so we return no policy - this
			// ensures the request is denied.
			if g.Status == statusDisabled {
				return nil, time.Time{}, nil
			}
		}

		policy, ok := c.cachedMappedPolicy(name, regUser, true)
		if ok {
			return policy.toSlice(), policy.UpdatedAt, nil
		}
		if !policyPresent {
			if err := store.loadMappedPolicy(context.TODO(), name, regUser, true, c.iamGroupPolicyMap); err != nil && !errors.Is(err, errNoSuchPolicy) {
				return nil, time.Time{}, err
			}
			policy, _ = c.cachedMappedPolicy(name, regUser, true)
			return policy.toSlice(), policy.UpdatedAt, nil
		}
		return nil, time.Time{}, nil
	}

	// returned policy could be empty, we use set to de-duplicate.
	var policies set.StringSet
	var updatedAt time.Time

	if store.getUsersSysType() == LDAPUsersSysType {
		// For LDAP policy mapping is part of STS users, we only need to lookup
		// those mappings.
		mp, ok := c.cachedMappedPolicy(name, stsUser, false)
		if !ok {
			// Attempt to load parent user mapping for STS accounts
			if err := store.loadMappedPolicy(context.TODO(), name, stsUser, false, c.iamSTSPolicyMap); err != nil && !errors.Is(err, errNoSuchPolicy) {
				return nil, time.Time{}, err
			}
			mp, _ = c.cachedMappedPolicy(name, stsUser, false)
		}
		if !c.revisions.mappingAllowed(getMappedPolicyPath(name, stsUser, false), mp) {
			mp = MappedPolicy{}
		}
		policies = set.CreateStringSet(mp.toSlice()...)
		updatedAt = mp.UpdatedAt
	} else {
		// When looking for a user's policies, we also check if the user
		// and the groups they are member of are enabled.
		u, ok := c.iamUsersMap[name]
		if ok {
			if !u.Credentials.IsValid() {
				return nil, time.Time{}, nil
			}
		}

		// For internal IDP regular/service account user accounts, the policy
		// mapping is iamUserPolicyMap. For STS accounts, the parent user would be
		// passed here and we lookup the mapping in iamSTSPolicyMap.
		mp, ok := c.cachedMappedPolicy(name, regUser, false)
		if !ok {
			if err := store.loadMappedPolicy(context.TODO(), name, regUser, false, c.iamUserPolicyMap); err != nil && !errors.Is(err, errNoSuchPolicy) {
				return nil, time.Time{}, err
			}
			mp, ok = c.cachedMappedPolicy(name, regUser, false)
			if !ok {
				// Since user "name" could be a parent user of an STS account, we look up
				// mappings for those too.
				mp, ok = c.cachedMappedPolicy(name, stsUser, false)
				if !ok {
					// Attempt to load parent user mapping for STS accounts
					if err := store.loadMappedPolicy(context.TODO(), name, stsUser, false, c.iamSTSPolicyMap); err != nil && !errors.Is(err, errNoSuchPolicy) {
						return nil, time.Time{}, err
					}
					mp, _ = c.cachedMappedPolicy(name, stsUser, false)
				}
			}
		}
		policies = set.CreateStringSet(mp.toSlice()...)

		for _, group := range u.Credentials.Groups {
			g, ok := c.iamGroupsMap[group]
			if ok {
				// Group is disabled, so we return no policy - this
				// ensures the request is denied.
				if g.Status == statusDisabled {
					return nil, time.Time{}, nil
				}
			}

			policy, ok := c.cachedMappedPolicy(group, regUser, true)
			if !ok {
				if err := store.loadMappedPolicy(context.TODO(), group, regUser, true, c.iamGroupPolicyMap); err != nil && !errors.Is(err, errNoSuchPolicy) {
					return nil, time.Time{}, err
				}
				policy, _ = c.cachedMappedPolicy(group, regUser, true)
			}

			for _, p := range policy.toSlice() {
				policies.Add(p)
			}
		}
		updatedAt = mp.UpdatedAt
	}

	for _, group := range c.effectiveUserGroups(name) {
		if store.getUsersSysType() == MinIOUsersSysType {
			g, ok := c.iamGroupsMap[group]
			if ok {
				// Group is disabled, so we return no policy - this
				// ensures the request is denied.
				if g.Status == statusDisabled {
					return nil, time.Time{}, nil
				}
			}
		}

		policy, ok := c.cachedMappedPolicy(group, regUser, true)
		if !ok {
			if err := store.loadMappedPolicy(context.TODO(), group, regUser, true, c.iamGroupPolicyMap); err != nil && !errors.Is(err, errNoSuchPolicy) {
				return nil, time.Time{}, err
			}
			policy, _ = c.cachedMappedPolicy(group, regUser, true)
		}

		for _, p := range policy.toSlice() {
			policies.Add(p)
		}
	}

	return policies.ToSlice(), updatedAt, nil
}

func (c *iamCache) updateUserWithClaims(key string, u UserIdentity) error {
	if u.Credentials.SessionToken != "" {
		jwtClaims, err := extractJWTClaims(u)
		if err != nil {
			return err
		}
		u.Credentials.Claims = jwtClaims.Map()
	}
	if u.Credentials.IsTemp() && !u.Credentials.IsServiceAccount() {
		c.iamSTSAccountsMap[key] = u
	} else {
		c.iamUsersMap[key] = u
	}
	c.updatedAt = time.Now()
	return nil
}

// IAMStorageAPI defines an interface for the IAM persistence layer
type IAMStorageAPI interface {
	// The role of the read-write lock is to prevent go routines from
	// concurrently reading and writing the IAM storage. The (r)lock()
	// functions return the iamCache. The cache can be safely written to
	// only when returned by `lock()`.
	lock() *iamCache
	unlock()
	rlock() *iamCache
	runlock()
	getUsersSysType() UsersSysType
	loadPolicyDoc(ctx context.Context, policy string, m map[string]PolicyDoc) error
	loadPolicyDocWithRetry(ctx context.Context, policy string, m map[string]PolicyDoc, retries int) error
	loadPolicyDocs(ctx context.Context, m map[string]PolicyDoc) error
	loadUser(ctx context.Context, user string, userType IAMUserType, m map[string]UserIdentity) error
	loadSecretKey(ctx context.Context, user string, userType IAMUserType) (string, error)
	loadUsers(ctx context.Context, userType IAMUserType, m map[string]UserIdentity) error
	loadGroup(ctx context.Context, group string, m map[string]GroupInfo) error
	loadGroups(ctx context.Context, m map[string]GroupInfo) error
	loadMappedPolicy(ctx context.Context, name string, userType IAMUserType, isGroup bool, m *xsync.MapOf[string, MappedPolicy]) error
	loadMappedPolicyWithRetry(ctx context.Context, name string, userType IAMUserType, isGroup bool, m *xsync.MapOf[string, MappedPolicy], retries int) error
	loadMappedPolicies(ctx context.Context, userType IAMUserType, isGroup bool, m *xsync.MapOf[string, MappedPolicy]) error
	saveIAMConfig(ctx context.Context, item any, path string, opts ...options) error
	loadIAMConfig(ctx context.Context, item any, path string) error
	deleteIAMConfig(ctx context.Context, path string) error
	listIAMConfigPaths(ctx context.Context) ([]string, error)
	revisionIndex() *iamRevisionIndex
}

// iamStorageWatcher is implemented by `IAMStorageAPI` implementers that
// additionally support watching storage for changes.
type iamStorageWatcher interface {
	watch(ctx context.Context, keyPath string) <-chan iamWatchEvent
}

// Set default canned policies only if not already overridden by users.
func setDefaultCannedPolicies(policies map[string]PolicyDoc) {
	for _, v := range policy.DefaultPolicies {
		if _, ok := policies[v.Name]; !ok {
			policies[v.Name] = defaultPolicyDoc(v.Definition)
		}
	}
}

// LoadIAMCache reads all IAM items and populates a new iamCache object and
// replaces the in-memory cache object.
func (store *IAMStoreSys) LoadIAMCache(ctx context.Context, firstTime bool) error {
	ctx = withIAMExpirationCleanup(ctx)
	bootstrapTraceMsgFirstTime := func(s string) {
		if firstTime {
			bootstrapTraceMsg(s)
		}
	}
	bootstrapTraceMsgFirstTime("loading IAM data")

	newCache := newIamCache()
	newCache.revisions = store.revisionIndex()

	loadedAt := time.Now()

	if iamOS, ok := store.IAMStorageAPI.(*IAMObjectStore); ok {
		err := iamOS.loadAllFromObjStore(ctx, newCache, firstTime)
		if err != nil {
			return err
		}
	} else {
		// Only non-object IAM store (i.e. only etcd backend).
		bootstrapTraceMsgFirstTime("loading policy documents")
		if err := store.loadPolicyDocs(ctx, newCache.iamPolicyDocsMap); err != nil {
			return err
		}

		// Sets default canned policies, if none are set.
		setDefaultCannedPolicies(newCache.iamPolicyDocsMap)

		if store.getUsersSysType() == MinIOUsersSysType {
			bootstrapTraceMsgFirstTime("loading regular users")
			if err := store.loadUsers(ctx, regUser, newCache.iamUsersMap); err != nil {
				return err
			}
			bootstrapTraceMsgFirstTime("loading regular groups")
			if err := store.loadGroups(ctx, newCache.iamGroupsMap); err != nil {
				return err
			}
		}

		bootstrapTraceMsgFirstTime("loading user policy mapping")
		// load polices mapped to users
		if err := store.loadMappedPolicies(ctx, regUser, false, newCache.iamUserPolicyMap); err != nil {
			return err
		}
		// External-IDP mappings are durable authorization records even when
		// no local service account currently refers to their parent.
		if err := store.loadMappedPolicies(ctx, stsUser, false, newCache.iamSTSPolicyMap); err != nil {
			return err
		}

		bootstrapTraceMsgFirstTime("loading group policy mapping")
		// load policies mapped to groups
		if err := store.loadMappedPolicies(ctx, regUser, true, newCache.iamGroupPolicyMap); err != nil {
			return err
		}

		bootstrapTraceMsgFirstTime("loading service accounts")
		// load service accounts
		if err := store.loadUsers(ctx, svcUser, newCache.iamUsersMap); err != nil {
			return err
		}

		newCache.buildUserGroupMemberships()
	}

	for name := range newCache.iamPolicyDocsMap {
		if store.revisionIndex().get(getPolicyDocPath(name)).Deleted {
			delete(newCache.iamPolicyDocsMap, name)
		}
	}

	cache := store.lock()
	defer store.unlock()

	// We should only update the in-memory cache if there were no changes
	// to the in-memory cache since the disk loading began. If there
	// were changes to the in-memory cache we should wait for the next
	// cycle until we can safely update the in-memory cache.
	//
	// An in-memory cache must be replaced only if we know for sure that the
	// values loaded from disk are not stale. They might be stale if the
	// cached.updatedAt is more recent than the refresh cycle began.
	if cache.updatedAt.Before(loadedAt) || firstTime {
		// No one has updated anything since the config was loaded,
		// so we just replace whatever is on the disk into memory.
		cache.iamGroupPolicyMap = newCache.iamGroupPolicyMap
		cache.iamGroupsMap = newCache.iamGroupsMap
		cache.iamPolicyDocsMap = newCache.iamPolicyDocsMap
		cache.iamUserGroupMemberships = newCache.iamUserGroupMemberships
		cache.iamUserPolicyMap = newCache.iamUserPolicyMap
		cache.iamUsersMap = newCache.iamUsersMap
		// For STS policy map, we need to merge the new cache with the existing
		// cache because the periodic IAM reload is partial. The periodic load
		// here is to account for STS policy mapping changes that should apply
		// for service accounts derived from such STS accounts (i.e. LDAP STS
		// accounts).
		newCache.iamSTSPolicyMap.Range(func(k string, v MappedPolicy) bool {
			cache.iamSTSPolicyMap.Store(k, v)
			return true
		})

		cache.updatedAt = time.Now()
	}

	return nil
}

// IAMStoreSys contains IAMStorageAPI to add higher-level methods on the storage
// layer.
type IAMStoreSys struct {
	IAMStorageAPI

	// Serialize cache writers independently of readers, so persistence can
	// release the cache lock without another writer invalidating its state.
	writeMu sync.Mutex

	group  *singleflight.Group
	policy *singleflight.Group
}

func (store *IAMStoreSys) lock() *iamCache {
	store.writeMu.Lock()
	return store.IAMStorageAPI.lock()
}

func (store *IAMStoreSys) unlock() {
	store.IAMStorageAPI.unlock()
	store.writeMu.Unlock()
}

// HasWatcher - returns if the storage system has a watcher.
func (store *IAMStoreSys) HasWatcher() bool {
	_, ok := store.IAMStorageAPI.(iamStorageWatcher)
	return ok
}

// GetUser - fetches credential from memory.
func (store *IAMStoreSys) GetUser(user string) (UserIdentity, bool) {
	cache := store.rlock()
	defer store.runlock()

	u, ok := cache.iamUsersMap[user]
	if !ok {
		// Check the sts map
		u, ok = cache.iamSTSAccountsMap[user]
	}
	if ok && u.Credentials.ParentUser != "" {
		r := cache.userRevocation(u.Credentials.ParentUser)
		if r.Deleted || !iamCredentialSurvivesRevocation(u.Credentials, r.RevokedBefore) {
			return UserIdentity{}, false
		}
	}
	return u, ok
}

// GetMappedPolicy - fetches mapped policy from memory.
func (store *IAMStoreSys) GetMappedPolicy(name string, isGroup bool) (MappedPolicy, bool) {
	cache := store.rlock()
	defer store.runlock()

	if isGroup {
		v, ok := cache.cachedMappedPolicy(name, regUser, true)
		return v, ok
	}
	return cache.cachedMappedPolicy(name, regUser, false)
}

// GroupNotificationHandler - updates in-memory cache on notification of
// change (e.g. peer notification for object storage and etcd watch
// notification).
func (store *IAMStoreSys) GroupNotificationHandler(ctx context.Context, group string) error {
	cache := store.lock()
	defer store.unlock()

	err := store.loadGroup(ctx, group, cache.iamGroupsMap)
	if err != nil && err != errNoSuchGroup {
		return err
	}

	if err == errNoSuchGroup {
		// group does not exist - so remove from memory.
		cache.removeGroupFromMembershipsMap(group)
		delete(cache.iamGroupsMap, group)
		cache.iamGroupPolicyMap.Delete(group)

		cache.updatedAt = time.Now()
		return nil
	}

	gi := cache.iamGroupsMap[group]

	// Updating the group memberships cache happens in two steps:
	//
	// 1. Remove the group from each user's list of memberships.
	// 2. Add the group to each member's list of memberships.
	//
	// This ensures that regardless of members being added or
	// removed, the cache stays current.
	cache.removeGroupFromMembershipsMap(group)
	cache.updateGroupMembershipsMap(group, &gi)
	cache.updatedAt = time.Now()
	return nil
}

// PolicyDBGet - fetches policies associated with the given user or group, and
// additional groups if provided.
func (store *IAMStoreSys) PolicyDBGet(name string, groups ...string) ([]string, error) {
	if name == "" {
		return nil, errInvalidArgument
	}

	cache := store.rlock()
	defer store.runlock()

	getPolicies := func() ([]string, error) {
		policies, _, err := cache.policyDBGet(store, name, false, false)
		if err != nil {
			return nil, err
		}

		userPolicyPresent := len(policies) > 0

		groupPolicies, err := cache.policyDBGetGroups(store, userPolicyPresent, groups...)
		if err != nil {
			return nil, err
		}

		policies = append(policies, groupPolicies...)
		return policies, nil
	}
	if store.policy != nil {
		val, err, _ := store.policy.Do(name, func() (any, error) {
			return getPolicies()
		})
		if err != nil {
			return nil, err
		}
		res, ok := val.([]string)
		if !ok {
			return nil, errors.New("unexpected policy type")
		}
		return res, nil
	}
	return getPolicies()
}

// AddUsersToGroup - adds users to group, creating the group if needed.
func (store *IAMStoreSys) AddUsersToGroup(ctx context.Context, group string, members []string) (updatedAt time.Time, err error) {
	if group == "" {
		return updatedAt, errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	if err := store.checkIAMRevision(ctx, getGroupInfoPath(group), false); err != nil {
		return updatedAt, err
	}

	gi, ok := cache.iamGroupsMap[group]
	if !ok {
		// Set group as enabled by default when it doesn't
		// exist.
		gi = newGroupInfo(nil)
	}
	if r := store.revisionIndex().get(getGroupInfoPath(group)); r.RevokedBefore.After(gi.RevokedBefore) {
		gi.RevokedBefore = r.RevokedBefore
	}
	gi, err = cache.addGroupMembers(ctx, gi, members)
	if err != nil {
		return updatedAt, err
	}

	if err := store.saveGroupInfo(context.WithValue(ctx, iamGroupMutationKey{}, iamGroupMutation{Members: members}), group, &gi); err != nil {
		return updatedAt, err
	}

	cache.iamGroupsMap[group] = gi

	cache.removeGroupFromMembershipsMap(group)
	cache.updateGroupMembershipsMap(group, &gi)

	cache.updatedAt = time.Now()
	return gi.UpdatedAt, nil
}

// helper function - does not take any locks. Updates only cache if
// updateCacheOnly is set.
func removeMembersFromGroup(ctx context.Context, store *IAMStoreSys, cache *iamCache, group string, members []string, updateCacheOnly bool) (updatedAt time.Time, err error) {
	gi, ok := cache.iamGroupsMap[group]
	if !ok {
		return updatedAt, errNoSuchGroup
	}

	s := set.CreateStringSet(gi.Members...)
	d := set.CreateStringSet(members...)
	gi.Members = s.Difference(d).ToSlice()

	gi.UpdatedAt = UTCNow()
	if !updateCacheOnly {
		err := store.saveGroupInfo(context.WithValue(ctx, iamGroupMutationKey{}, iamGroupMutation{Members: members, Remove: true}), group, &gi)
		if err != nil {
			return updatedAt, err
		}
	}
	cache.iamGroupsMap[group] = gi

	// update user-group membership map
	for _, member := range members {
		gset := cache.iamUserGroupMemberships[member]
		if gset == nil {
			continue
		}
		gset.Remove(group)
		cache.iamUserGroupMemberships[member] = gset
	}

	cache.updatedAt = time.Now()
	return gi.UpdatedAt, nil
}

// RemoveUsersFromGroup - removes users from group, deleting it if it is empty.
func (store *IAMStoreSys) RemoveUsersFromGroup(ctx context.Context, group string, members []string) (updatedAt time.Time, err error) {
	if group == "" {
		return updatedAt, errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	_, replicated := iamReplicationTime(ctx)
	if len(members) != 0 {
		if err := store.checkIAMRevision(ctx, getGroupInfoPath(group), false); err != nil {
			return updatedAt, err
		}
	}

	// Validate that all members exist.
	for _, member := range members {
		u, ok := cache.iamUsersMap[member]
		if !ok {
			return updatedAt, errNoSuchUser
		}
		cr := u.Credentials
		if cr.IsTemp() || cr.IsServiceAccount() {
			return updatedAt, errIAMActionNotAllowed
		}
	}

	gi, ok := cache.iamGroupsMap[group]
	if !ok && (!replicated || len(members) != 0) {
		return updatedAt, errNoSuchGroup
	}

	// Check if attempting to delete a non-empty group.
	if !replicated && len(members) == 0 && len(cache.effectiveGroupMembers(gi)) != 0 {
		return updatedAt, errGroupNotEmpty
	}

	if len(members) == 0 {
		// Commit the group revision before attempting dependent cleanup. A
		// newer mapping cannot veto a deletion or conceal an older boundary.
		op := &iamGroupRevocation{requireEmpty: !replicated}
		err := store.saveIAMRevision(ctx, getGroupInfoPath(group), op)
		retained := errors.Is(err, errIAMRevocationRetained)
		if err != nil && !retained {
			return updatedAt, err
		}
		updatedAt = op.RevokedBefore
		cache.removeGroupFromMembershipsMap(group)
		if retained {
			cache.iamGroupsMap[group] = op.GroupInfo
			cache.updateGroupMembershipsMap(group, &op.GroupInfo)
		} else {
			delete(cache.iamGroupsMap, group)
		}
		cache.updatedAt = time.Now()
		cleanupErr := store.deleteMappedPolicy(withIAMReplicationTime(ctx, updatedAt), group, regUser, true)
		if mp, ok := cache.iamGroupPolicyMap.Load(group); ok && !mp.UpdatedAt.After(updatedAt) {
			cache.iamGroupPolicyMap.Delete(group)
		}
		if cleanupErr != nil && !errors.Is(cleanupErr, errIAMStaleUpdate) {
			return updatedAt, &iamCommittedCleanupError{err: cleanupErr, retained: retained}
		}
		return updatedAt, nil
	}

	return removeMembersFromGroup(ctx, store, cache, group, members, false)
}

// SetGroupStatus - updates group status
func (store *IAMStoreSys) SetGroupStatus(ctx context.Context, group string, enabled bool) (updatedAt time.Time, err error) {
	if group == "" {
		return updatedAt, errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	gi, ok := cache.iamGroupsMap[group]
	if !ok {
		return updatedAt, errNoSuchGroup
	}

	if enabled {
		gi.Status = statusEnabled
	} else {
		gi.Status = statusDisabled
	}
	gi.UpdatedAt = UTCNow()
	if err := store.saveGroupInfo(context.WithValue(ctx, iamGroupMutationKey{}, iamGroupMutation{StatusOnly: true}), group, &gi); err != nil {
		return gi.UpdatedAt, err
	}

	cache.iamGroupsMap[group] = gi
	cache.updatedAt = time.Now()

	return gi.UpdatedAt, nil
}

// GetGroupDescription - builds up group description
func (store *IAMStoreSys) GetGroupDescription(group string) (gd madmin.GroupDesc, err error) {
	cache := store.rlock()
	defer store.runlock()

	ps, updatedAt, err := cache.policyDBGet(store, group, true, false)
	if err != nil {
		return gd, err
	}

	policy := strings.Join(ps, ",")

	if store.getUsersSysType() != MinIOUsersSysType {
		return madmin.GroupDesc{
			Name:      group,
			Policy:    policy,
			UpdatedAt: updatedAt,
		}, nil
	}

	gi, ok := cache.iamGroupsMap[group]
	if !ok {
		return gd, errNoSuchGroup
	}

	return madmin.GroupDesc{
		Name:      group,
		Status:    gi.Status,
		Members:   cache.effectiveGroupMembers(gi),
		Policy:    policy,
		UpdatedAt: gi.UpdatedAt,
	}, nil
}

// updateGroups updates the group from the persistent store, and also related policy mapping if any.
func (store *IAMStoreSys) updateGroups(ctx context.Context, cache *iamCache) (res []string, err error) {
	groupSet := set.NewStringSet()
	if iamOS, ok := store.IAMStorageAPI.(*IAMObjectStore); ok {
		listedConfigItems, err := iamOS.listAllIAMConfigItems(ctx)
		if err != nil {
			return nil, err
		}
		if store.getUsersSysType() == MinIOUsersSysType {
			groupsList := listedConfigItems[groupsListKey]
			for _, item := range groupsList {
				group := path.Dir(item)
				if err = iamOS.loadGroup(ctx, group, cache.iamGroupsMap); err != nil && !errors.Is(err, errNoSuchGroup) {
					return nil, fmt.Errorf("unable to load the group: %w", err)
				}
				if errors.Is(err, errNoSuchGroup) {
					delete(cache.iamGroupsMap, group)
					continue
				}
				groupSet.Add(group)
			}
		}

		groupPolicyMappingsList := listedConfigItems[policyDBGroupsListKey]
		for _, item := range groupPolicyMappingsList {
			group := strings.TrimSuffix(item, ".json")
			if err = iamOS.loadMappedPolicy(ctx, group, regUser, true, cache.iamGroupPolicyMap); err != nil && !errors.Is(err, errNoSuchPolicy) {
				return nil, fmt.Errorf("unable to load the policy mapping for the group: %w", err)
			}
			if errors.Is(err, errNoSuchPolicy) {
				cache.iamGroupPolicyMap.Delete(group)
				continue
			}
			groupSet.Add(group)
		}

		return groupSet.ToSlice(), nil
	}

	// For etcd just return from cache.
	for k := range cache.iamGroupsMap {
		groupSet.Add(k)
	}

	cache.iamGroupPolicyMap.Range(func(k string, v MappedPolicy) bool {
		groupSet.Add(k)
		return true
	})

	return groupSet.ToSlice(), nil
}

// ListGroups - lists groups. Since this is not going to be a frequent
// operation, we fetch this info from storage, and refresh the cache as well.
func (store *IAMStoreSys) ListGroups(ctx context.Context) (res []string, err error) {
	cache := store.lock()
	defer store.unlock()

	return store.updateGroups(ctx, cache)
}

// listGroups - lists groups - fetch groups from cache
func (store *IAMStoreSys) listGroups(ctx context.Context) (res []string, err error) {
	cache := store.rlock()
	defer store.runlock()

	if store.getUsersSysType() == MinIOUsersSysType {
		for k := range cache.iamGroupsMap {
			res = append(res, k)
		}
	}

	if store.getUsersSysType() == LDAPUsersSysType {
		cache.iamGroupPolicyMap.Range(func(k string, _ MappedPolicy) bool {
			res = append(res, k)
			return true
		})
	}
	return res, err
}

// PolicyDBUpdate - adds or removes given policies to/from the user or group's
// policy associations.
func (store *IAMStoreSys) PolicyDBUpdate(ctx context.Context, name string, isGroup bool,
	userType IAMUserType, policies []string, isAttach bool) (updatedAt time.Time,
	addedOrRemoved, effectivePolicies []string, err error,
) {
	if name == "" {
		err = errInvalidArgument
		return updatedAt, addedOrRemoved, effectivePolicies, err
	}

	cache := store.lock()
	defer store.unlock()

	// Load existing policy mapping
	var mp MappedPolicy
	if !isGroup {
		if userType == stsUser {
			stsMap := xsync.NewMapOf[string, MappedPolicy]()

			// Attempt to load parent user mapping for STS accounts
			store.loadMappedPolicy(context.TODO(), name, stsUser, false, stsMap)

			mp, _ = stsMap.Load(name)
		} else {
			mp, _ = cache.iamUserPolicyMap.Load(name)
		}
	} else {
		if store.getUsersSysType() == MinIOUsersSysType {
			g, ok := cache.iamGroupsMap[name]
			if !ok {
				err = errNoSuchGroup
				return updatedAt, addedOrRemoved, effectivePolicies, err
			}

			if g.Status == statusDisabled {
				err = errGroupDisabled
				return updatedAt, addedOrRemoved, effectivePolicies, err
			}
		}
		mp, _ = cache.iamGroupPolicyMap.Load(name)
	}

	// Compute net policy change effect and updated policy mapping
	existingPolicySet := mp.policySet()
	policiesToUpdate := set.CreateStringSet(policies...)
	var newPolicySet set.StringSet
	newPolicyMapping := mp
	if isAttach {
		// new policies to attach => inputPolicies - existing (set difference)
		policiesToUpdate = policiesToUpdate.Difference(existingPolicySet)
		// validate that new policies to add are defined.
		for _, p := range policiesToUpdate.ToSlice() {
			if _, found := cache.iamPolicyDocsMap[p]; !found {
				err = errNoSuchPolicy
				return updatedAt, addedOrRemoved, effectivePolicies, err
			}
		}
		newPolicySet = existingPolicySet.Union(policiesToUpdate)
	} else {
		// policies to detach => inputPolicies ∩ existing (intersection)
		policiesToUpdate = policiesToUpdate.Intersection(existingPolicySet)
		newPolicySet = existingPolicySet.Difference(policiesToUpdate)
	}
	// We return an error if the requested policy update will have no effect.
	if policiesToUpdate.IsEmpty() {
		err = errNoPolicyToAttachOrDetach
		return updatedAt, addedOrRemoved, effectivePolicies, err
	}

	newPolicies := newPolicySet.ToSlice()
	newPolicyMapping.Policies = strings.Join(newPolicies, ",")
	newPolicyMapping.UpdatedAt = UTCNow()
	addedOrRemoved = policiesToUpdate.ToSlice()

	// In case of detach operation, it is possible that no policies are mapped -
	// in this case, we delete the mapping from the store.
	if len(newPolicies) == 0 {
		newPolicyMapping.Deleted = true
		if err = store.saveMappedPolicy(ctx, name, userType, isGroup, &newPolicyMapping); err != nil && !errors.Is(err, errNoSuchPolicy) {
			return updatedAt, addedOrRemoved, effectivePolicies, err
		}
		if !isGroup {
			if userType == stsUser {
				cache.iamSTSPolicyMap.Delete(name)
			} else {
				cache.iamUserPolicyMap.Delete(name)
			}
		} else {
			cache.iamGroupPolicyMap.Delete(name)
		}
	} else {
		if err = store.saveMappedPolicy(ctx, name, userType, isGroup, &newPolicyMapping); err != nil {
			return updatedAt, addedOrRemoved, effectivePolicies, err
		}
		if !isGroup {
			if userType == stsUser {
				cache.iamSTSPolicyMap.Store(name, newPolicyMapping)
			} else {
				cache.iamUserPolicyMap.Store(name, newPolicyMapping)
			}
		} else {
			cache.iamGroupPolicyMap.Store(name, newPolicyMapping)
		}
	}

	cache.updatedAt = UTCNow()
	return newPolicyMapping.UpdatedAt, addedOrRemoved, newPolicies, nil
}

// PolicyDBSet - update the policy mapping for the given user or group in
// storage and in cache. We do not check for the existence of the user here
// since users can be virtual, such as for:
//   - LDAP users
//   - CommonName for STS accounts generated by AssumeRoleWithCertificate
func (store *IAMStoreSys) PolicyDBSet(ctx context.Context, name, policy string, userType IAMUserType, isGroup bool) (updatedAt time.Time, err error) {
	if name == "" {
		return updatedAt, errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	if err := store.checkIAMRevision(ctx, getMappedPolicyPath(name, userType, isGroup), policy == ""); err != nil {
		return updatedAt, err
	}

	// Handle policy mapping removal.
	if policy == "" {
		if store.getUsersSysType() == LDAPUsersSysType {
			// Add a fallback removal towards previous content that may come back
			// as a ghost user due to lack of delete, this change occurred
			// introduced in PR #11840
			store.deleteMappedPolicy(ctx, name, regUser, false)
		}
		mp := MappedPolicy{Version: 1, Deleted: true}
		err := store.saveMappedPolicy(ctx, name, userType, isGroup, &mp)
		if err != nil && !errors.Is(err, errNoSuchPolicy) {
			return updatedAt, err
		}
		if !isGroup {
			if userType == stsUser {
				cache.iamSTSPolicyMap.Delete(name)
			} else {
				cache.iamUserPolicyMap.Delete(name)
			}
		} else {
			cache.iamGroupPolicyMap.Delete(name)
		}
		cache.updatedAt = time.Now()
		return mp.UpdatedAt, nil
	}

	// Handle policy mapping set/update
	mp := newMappedPolicy(policy)
	for _, p := range mp.toSlice() {
		if _, found := cache.iamPolicyDocsMap[p]; !found {
			return updatedAt, errNoSuchPolicy
		}
	}

	if err := store.saveMappedPolicy(ctx, name, userType, isGroup, &mp); err != nil {
		return updatedAt, err
	}
	if !isGroup {
		if userType == stsUser {
			cache.iamSTSPolicyMap.Store(name, mp)
		} else {
			cache.iamUserPolicyMap.Store(name, mp)
		}
	} else {
		cache.iamGroupPolicyMap.Store(name, mp)
	}
	cache.updatedAt = time.Now()
	return mp.UpdatedAt, nil
}

// PolicyNotificationHandler - loads given policy from storage. If not present,
// deletes from cache. This notification only reads from storage, and updates
// cache. When the notification is for a policy deletion, it updates the
// user-policy and group-policy maps as well.
func (store *IAMStoreSys) PolicyNotificationHandler(ctx context.Context, policy string) error {
	if policy == "" {
		return errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	err := store.loadPolicyDoc(ctx, policy, cache.iamPolicyDocsMap)
	if errors.Is(err, errNoSuchPolicy) {
		// policy was deleted, update cache.
		delete(cache.iamPolicyDocsMap, policy)

		// update user policy map
		cache.iamUserPolicyMap.Range(func(u string, mp MappedPolicy) bool {
			pset := mp.policySet()
			if !pset.Contains(policy) {
				return true
			}
			if store.getUsersSysType() == MinIOUsersSysType {
				_, ok := cache.iamUsersMap[u]
				if !ok {
					// happens when account is deleted or
					// expired.
					cache.iamUserPolicyMap.Delete(u)
					return true
				}
			}
			pset.Remove(policy)
			cache.iamUserPolicyMap.Store(u, newMappedPolicy(strings.Join(pset.ToSlice(), ",")))
			return true
		})

		// update group policy map
		cache.iamGroupPolicyMap.Range(func(g string, mp MappedPolicy) bool {
			pset := mp.policySet()
			if !pset.Contains(policy) {
				return true
			}
			pset.Remove(policy)
			cache.iamGroupPolicyMap.Store(g, newMappedPolicy(strings.Join(pset.ToSlice(), ",")))
			return true
		})

		cache.updatedAt = time.Now()
		return nil
	}
	return err
}

// DeletePolicy - deletes policy from storage and cache. When this called in
// response to a notification (i.e. isFromNotification = true), it skips the
// validation of policy usage and the attempt to delete in the backend as well
// (as this is already done by the notifying node).
func (store *IAMStoreSys) DeletePolicy(ctx context.Context, policy string, isFromNotification bool) error {
	if policy == "" {
		return errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	if !isFromNotification {
		if err := store.checkIAMRevision(ctx, getPolicyDocPath(policy), true); err != nil {
			return err
		}
		if _, replicated := iamReplicationTime(ctx); !replicated {
			if _, exists := cache.iamPolicyDocsMap[policy]; !exists {
				// Preserve idempotent local deletion without creating a durable
				// revocation for a misspelled/nonexistent policy name.
				return nil
			}
			// Check if policy is mapped to any existing user or group. If so, we do not
			// allow deletion of the policy. If the policy is mapped to an STS account,
			// we do allow deletion.
			users := []string{}
			groups := []string{}
			cache.iamUserPolicyMap.Range(func(u string, mp MappedPolicy) bool {
				pset := mp.policySet()
				if store.getUsersSysType() == MinIOUsersSysType {
					if _, ok := cache.iamUsersMap[u]; !ok {
						// This case can happen when a temporary account is
						// deleted or expired - remove it from userPolicyMap.
						cache.iamUserPolicyMap.Delete(u)
						return true
					}
				}
				if pset.Contains(policy) {
					users = append(users, u)
				}
				return true
			})
			cache.iamGroupPolicyMap.Range(func(g string, mp MappedPolicy) bool {
				pset := mp.policySet()
				if pset.Contains(policy) {
					groups = append(groups, g)
				}
				return true
			})
			if len(users) != 0 || len(groups) != 0 {
				return errPolicyInUse
			}
		}

		err := store.deletePolicyDoc(ctx, policy)
		if errors.Is(err, errNoSuchPolicy) {
			// Ignore error if policy is already deleted.
			err = nil
		}
		if err != nil {
			return err
		}
	}

	delete(cache.iamPolicyDocsMap, policy)
	cache.updatedAt = time.Now()

	return nil
}

// GetPolicy - gets the policy definition. Allows specifying multiple comma
// separated policies - returns a combined policy.
func (store *IAMStoreSys) GetPolicy(name string) (policy.Policy, error) {
	if name == "" {
		return policy.Policy{}, errInvalidArgument
	}

	cache := store.rlock()
	defer store.runlock()

	policies := newMappedPolicy(name).toSlice()
	var toMerge []policy.Policy
	for _, policy := range policies {
		if policy == "" {
			continue
		}
		v, ok := cache.iamPolicyDocsMap[policy]
		if !ok {
			return v.Policy, errNoSuchPolicy
		}
		toMerge = append(toMerge, v.Policy)
	}
	if len(toMerge) == 0 {
		return policy.Policy{}, errNoSuchPolicy
	}
	return policy.MergePolicies(toMerge...), nil
}

// GetPolicyDoc - gets the policy doc which has the policy and some metadata.
// Exactly one policy must be specified here.
func (store *IAMStoreSys) GetPolicyDoc(name string) (r PolicyDoc, err error) {
	name = strings.TrimSpace(name)
	if name == "" {
		return r, errInvalidArgument
	}

	cache := store.rlock()
	defer store.runlock()

	v, ok := cache.iamPolicyDocsMap[name]
	if !ok {
		return r, errNoSuchPolicy
	}
	return v, nil
}

// SetPolicy - creates a policy with name.
func (store *IAMStoreSys) SetPolicy(ctx context.Context, name string, policy policy.Policy) (time.Time, error) {
	if policy.IsEmpty() || name == "" {
		return time.Time{}, errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	var (
		d  PolicyDoc
		ok bool
	)
	if d, ok = cache.iamPolicyDocsMap[name]; ok {
		d.update(policy)
	} else {
		d = newPolicyDoc(policy)
	}

	if err := store.savePolicyDoc(ctx, name, &d); err != nil {
		return d.UpdateDate, err
	}

	cache.iamPolicyDocsMap[name] = d
	cache.updatedAt = time.Now()

	return d.UpdateDate, nil
}

// ListPolicies - fetches all policies from storage and updates cache as well.
// If bucketName is non-empty, returns policies matching the bucket.
func (store *IAMStoreSys) ListPolicies(ctx context.Context, bucketName string) (map[string]policy.Policy, error) {
	cache := store.lock()
	defer store.unlock()

	m := map[string]PolicyDoc{}
	err := store.loadPolicyDocs(ctx, m)
	if err != nil {
		return nil, err
	}

	// Sets default canned policies
	setDefaultCannedPolicies(m)

	cache.iamPolicyDocsMap = m
	cache.updatedAt = time.Now()

	ret := map[string]policy.Policy{}
	for k, v := range m {
		if bucketName == "" || v.Policy.MatchResource(bucketName) {
			ret[k] = v.Policy
		}
	}

	return ret, nil
}

// ListPolicyDocs - fetches all policy docs from storage and updates cache as well.
// If bucketName is non-empty, returns policy docs matching the bucket.
func (store *IAMStoreSys) ListPolicyDocs(ctx context.Context, bucketName string) (map[string]PolicyDoc, error) {
	cache := store.lock()
	defer store.unlock()

	m := map[string]PolicyDoc{}
	err := store.loadPolicyDocs(ctx, m)
	if err != nil {
		return nil, err
	}

	// Sets default canned policies
	setDefaultCannedPolicies(m)

	cache.iamPolicyDocsMap = m
	cache.updatedAt = time.Now()

	ret := map[string]PolicyDoc{}
	for k, v := range m {
		if bucketName == "" || v.Policy.MatchResource(bucketName) {
			ret[k] = v
		}
	}

	return ret, nil
}

// fetches all policy docs from cache.
// If bucketName is non-empty, returns policy docs matching the bucket.
func (store *IAMStoreSys) listPolicyDocs(ctx context.Context, bucketName string) (map[string]PolicyDoc, error) {
	cache := store.rlock()
	defer store.runlock()
	ret := map[string]PolicyDoc{}
	for k, v := range cache.iamPolicyDocsMap {
		if bucketName == "" || v.Policy.MatchResource(bucketName) {
			ret[k] = v
		}
	}
	return ret, nil
}

// helper function - does not take locks.
func filterPolicies(cache *iamCache, policyName string, bucketName string) (string, policy.Policy) {
	var policies []string
	mp := newMappedPolicy(policyName)
	var toMerge []policy.Policy
	for _, policy := range mp.toSlice() {
		if policy == "" {
			continue
		}
		p, found := cache.iamPolicyDocsMap[policy]
		if !found {
			continue
		}
		if bucketName == "" || p.Policy.MatchResource(bucketName) {
			policies = append(policies, policy)
			toMerge = append(toMerge, p.Policy)
		}
	}
	return strings.Join(policies, ","), policy.MergePolicies(toMerge...)
}

// MergePolicies - accepts a comma separated list of policy names as a string
// and returns only policies that currently exist in MinIO. It includes hot loading
// of policies if not in the memory
func (store *IAMStoreSys) MergePolicies(policyName string) (string, policy.Policy) {
	var policies []string
	var missingPolicies []string
	var toMerge []policy.Policy

	cache := store.rlock()
	for _, policy := range newMappedPolicy(policyName).toSlice() {
		if policy == "" {
			continue
		}
		p, found := cache.iamPolicyDocsMap[policy]
		if !found {
			missingPolicies = append(missingPolicies, policy)
			continue
		}
		policies = append(policies, policy)
		toMerge = append(toMerge, p.Policy)
	}
	store.runlock()

	if len(missingPolicies) > 0 {
		m := make(map[string]PolicyDoc)
		for _, policy := range missingPolicies {
			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
			_ = store.loadPolicyDoc(ctx, policy, m)
			cancel()
		}

		cache := store.lock()
		maps.Copy(cache.iamPolicyDocsMap, m)
		store.unlock()

		for policy, p := range m {
			policies = append(policies, policy)
			toMerge = append(toMerge, p.Policy)
		}
	}

	return strings.Join(policies, ","), policy.MergePolicies(toMerge...)
}

// GetBucketUsers - returns users (not STS or service accounts) that have access
// to the bucket. User is included even if a group policy that grants access to
// the bucket is disabled.
func (store *IAMStoreSys) GetBucketUsers(bucket string) (map[string]madmin.UserInfo, error) {
	if bucket == "" {
		return nil, errInvalidArgument
	}

	cache := store.rlock()
	defer store.runlock()

	result := map[string]madmin.UserInfo{}
	for k, v := range cache.iamUsersMap {
		c := v.Credentials
		if c.IsTemp() || c.IsServiceAccount() {
			continue
		}
		var policies []string
		mp, ok := cache.cachedMappedPolicy(k, regUser, false)
		if ok {
			policies = append(policies, mp.Policies)
			for _, group := range cache.effectiveUserGroups(k) {
				if nmp, ok := cache.cachedMappedPolicy(group, regUser, true); ok {
					policies = append(policies, nmp.Policies)
				}
			}
		}
		matchedPolicies, _ := filterPolicies(cache, strings.Join(policies, ","), bucket)
		if len(matchedPolicies) > 0 {
			result[k] = madmin.UserInfo{
				PolicyName: matchedPolicies,
				Status: func() madmin.AccountStatus {
					if c.IsValid() {
						return madmin.AccountEnabled
					}
					return madmin.AccountDisabled
				}(),
				MemberOf: cache.effectiveUserGroups(k),
			}
		}
	}

	return result, nil
}

// GetUsers - returns all users (not STS or service accounts).
func (store *IAMStoreSys) GetUsers() map[string]madmin.UserInfo {
	cache := store.rlock()
	defer store.runlock()

	result := map[string]madmin.UserInfo{}
	for k, u := range cache.iamUsersMap {
		v := u.Credentials

		if v.IsTemp() || v.IsServiceAccount() {
			continue
		}
		pl, _ := cache.cachedMappedPolicy(k, regUser, false)
		result[k] = madmin.UserInfo{
			PolicyName: pl.Policies,
			Status: func() madmin.AccountStatus {
				if v.IsValid() {
					return madmin.AccountEnabled
				}
				return madmin.AccountDisabled
			}(),
			MemberOf:  cache.effectiveUserGroups(k),
			UpdatedAt: pl.UpdatedAt,
		}
	}

	return result
}

// GetUsersWithMappedPolicies - safely returns the name of access keys with associated policies
func (store *IAMStoreSys) GetUsersWithMappedPolicies() map[string]string {
	cache := store.rlock()
	defer store.runlock()

	result := make(map[string]string)
	cache.iamUserPolicyMap.Range(func(k string, v MappedPolicy) bool {
		result[k] = v.Policies
		return true
	})
	cache.iamSTSPolicyMap.Range(func(k string, v MappedPolicy) bool {
		result[k] = v.Policies
		return true
	})
	return result
}

// GetUserInfo - get info on a user.
func (store *IAMStoreSys) GetUserInfo(name string) (u madmin.UserInfo, err error) {
	if name == "" {
		return u, errInvalidArgument
	}

	cache := store.rlock()
	defer store.runlock()

	if store.getUsersSysType() != MinIOUsersSysType {
		// If the user has a mapped policy or is a member of a group, we
		// return that info. Otherwise we return error.
		var groups []string
		for _, v := range cache.iamUsersMap {
			if v.Credentials.ParentUser == name {
				groups = v.Credentials.Groups
				break
			}
		}
		for _, v := range cache.iamSTSAccountsMap {
			if v.Credentials.ParentUser == name {
				groups = v.Credentials.Groups
				break
			}
		}
		mappedPolicy, ok := cache.cachedMappedPolicy(name, regUser, false)
		if !ok {
			mappedPolicy, ok = cache.cachedMappedPolicy(name, stsUser, false)
		}
		if !ok {
			// Attempt to load parent user mapping for STS accounts
			store.loadMappedPolicy(context.TODO(), name, stsUser, false, cache.iamSTSPolicyMap)
			mappedPolicy, ok = cache.cachedMappedPolicy(name, stsUser, false)
			if !ok {
				return u, errNoSuchUser
			}
		}

		return madmin.UserInfo{
			PolicyName: mappedPolicy.Policies,
			MemberOf:   groups,
			UpdatedAt:  mappedPolicy.UpdatedAt,
		}, nil
	}

	ui, found := cache.iamUsersMap[name]
	if !found {
		return u, errNoSuchUser
	}
	cred := ui.Credentials
	if cred.IsTemp() || cred.IsServiceAccount() {
		return u, errIAMActionNotAllowed
	}
	pl, _ := cache.cachedMappedPolicy(name, regUser, false)
	return madmin.UserInfo{
		PolicyName: pl.Policies,
		Status: func() madmin.AccountStatus {
			if cred.IsValid() {
				return madmin.AccountEnabled
			}
			return madmin.AccountDisabled
		}(),
		MemberOf:  cache.effectiveUserGroups(name),
		UpdatedAt: ui.UpdatedAt,
	}, nil
}

// PolicyMappingNotificationHandler - handles updating a policy mapping from storage.
func (store *IAMStoreSys) PolicyMappingNotificationHandler(ctx context.Context, userOrGroup string, isGroup bool, userType IAMUserType) error {
	if userOrGroup == "" {
		return errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	var m *xsync.MapOf[string, MappedPolicy]
	switch {
	case isGroup:
		m = cache.iamGroupPolicyMap
	case userType == stsUser:
		m = cache.iamSTSPolicyMap
	default:
		m = cache.iamUserPolicyMap
	}
	err := store.loadMappedPolicy(ctx, userOrGroup, userType, isGroup, m)
	if errors.Is(err, errNoSuchPolicy) {
		// This means that the policy mapping was deleted, so we update
		// the cache.
		m.Delete(userOrGroup)
		cache.updatedAt = time.Now()

		err = nil
	}
	return err
}

// UserDeletionNotificationHandler refreshes all cached state affected by a
// parent deletion. Reloading only a recreated parent would retain the older
// children, policy, and group memberships in this node's cache.
func (store *IAMStoreSys) UserDeletionNotificationHandler(ctx context.Context, accessKey string) error {
	if accessKey == "" {
		return errInvalidArgument
	}
	cache := store.rlock()
	groups := cache.iamUserGroupMemberships[accessKey].ToSlice()
	children := make(map[string]IAMUserType)
	for key, u := range cache.iamUsersMap {
		if u.Credentials.ParentUser == accessKey && u.Credentials.IsServiceAccount() {
			children[key] = svcUser
		}
	}
	store.runlock()

	if err := store.UserNotificationHandler(ctx, accessKey, regUser); err != nil {
		return err
	}
	if err := store.PolicyMappingNotificationHandler(ctx, accessKey, false, regUser); err != nil {
		return err
	}
	// Temporary credentials are loaded on demand. Invalidate their cached
	// copies; a later request must revalidate them against persisted state.
	cache = store.lock()
	for key, u := range cache.iamSTSAccountsMap {
		if u.Credentials.ParentUser == accessKey {
			delete(cache.iamSTSAccountsMap, key)
		}
	}
	cache.updatedAt = time.Now()
	store.unlock()
	for key, userType := range children {
		if err := store.UserNotificationHandler(ctx, key, userType); err != nil {
			return err
		}
	}
	for _, group := range groups {
		if err := store.GroupNotificationHandler(ctx, group); err != nil {
			return err
		}
	}
	return nil
}

// UserNotificationHandler - handles updating a user/STS account/service account
// from storage.
func (store *IAMStoreSys) UserNotificationHandler(ctx context.Context, accessKey string, userType IAMUserType) error {
	if accessKey == "" {
		return errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	var m map[string]UserIdentity
	switch userType {
	case stsUser:
		m = cache.iamSTSAccountsMap
	default:
		m = cache.iamUsersMap
	}
	err := store.loadUser(ctx, accessKey, userType, m)

	if err == errNoSuchUser {
		// User was deleted - we update the cache.
		delete(m, accessKey)

		// Since cache was updated, we update the timestamp.
		defer func() {
			cache.updatedAt = time.Now()
		}()

		// 1. Start with updating user-group memberships
		if store.getUsersSysType() == MinIOUsersSysType {
			memberOf := cache.iamUserGroupMemberships[accessKey].ToSlice()
			for _, group := range memberOf {
				_, removeErr := removeMembersFromGroup(ctx, store, cache, group, []string{accessKey}, true)
				if removeErr == errNoSuchGroup {
					removeErr = nil
				}
				if removeErr != nil {
					return removeErr
				}
			}
		}

		// 2. Remove any derived credentials from memory
		if userType == regUser {
			for k, u := range cache.iamUsersMap {
				if u.Credentials.IsServiceAccount() && u.Credentials.ParentUser == accessKey {
					delete(cache.iamUsersMap, k)
				}
			}
			for k, u := range cache.iamSTSAccountsMap {
				if u.Credentials.ParentUser == accessKey {
					delete(cache.iamSTSAccountsMap, k)
				}
			}
		}

		// 3. Delete any mapped policy
		cache.iamUserPolicyMap.Delete(accessKey)

		return nil
	}

	if err != nil {
		return err
	}

	// Since cache was updated, we update the timestamp.
	defer func() {
		cache.updatedAt = time.Now()
	}()

	cred := m[accessKey].Credentials
	switch userType {
	case stsUser:
		// For STS accounts a policy is mapped to the parent user (if a mapping exists).
		err = store.loadMappedPolicy(ctx, cred.ParentUser, userType, false, cache.iamSTSPolicyMap)
	case svcUser:
		// For service accounts, the parent may be a regular (internal) IDP
		// user or a "virtual" user (parent of an STS account).
		//
		// If parent is a regular user => policy mapping is done on that parent itself.
		//
		// If parent is "virtual" => policy mapping is done on the virtual
		// parent and that virtual parent is an stsUser.
		//
		// To load the appropriate mapping, we check the parent user type.
		_, parentIsRegularUser := cache.iamUsersMap[cred.ParentUser]
		if parentIsRegularUser {
			err = store.loadMappedPolicy(ctx, cred.ParentUser, regUser, false, cache.iamUserPolicyMap)
		} else {
			err = store.loadMappedPolicy(ctx, cred.ParentUser, stsUser, false, cache.iamSTSPolicyMap)
		}
	case regUser:
		// For regular users, we load the mapped policy.
		err = store.loadMappedPolicy(ctx, accessKey, userType, false, cache.iamUserPolicyMap)
	default:
		// This is just to ensure that we have covered all cases for new
		// code in future.
		panic("unknown user type")
	}
	// Ignore policy not mapped error
	if err != nil && !errors.Is(err, errNoSuchPolicy) {
		return err
	}

	return nil
}

// DeleteUser - deletes a user from storage and cache. This only used with
// long-term users and service accounts, not STS.
func (store *IAMStoreSys) DeleteUser(ctx context.Context, accessKey string, userType IAMUserType) error {
	if accessKey == "" {
		return errInvalidArgument
	}
	cache := store.lock()
	defer store.unlock()

	// The identity record is the commit point. A failure in later cleanup
	// cannot undo its durable revocation or resurrect old dependent grants.
	var identity UserIdentity
	var err error
	retained := false
	if userType == regUser {
		op := &iamUserRevocation{}
		err = store.saveIAMRevision(ctx, getUserIdentityPath(accessKey, userType), op)
		identity, retained = op.UserIdentity, errors.Is(err, errIAMRevocationRetained)
	} else {
		identity = UserIdentity{Version: 1, Deleted: true}
		err = store.saveUserIdentity(ctx, accessKey, userType, &identity)
	}
	if err != nil && !retained {
		return err
	}
	if retained {
		cache.iamUsersMap[accessKey] = identity
	} else {
		delete(cache.iamUsersMap, accessKey)
		delete(cache.iamSTSAccountsMap, accessKey)
	}
	cache.updatedAt = time.Now()
	if store.group != nil {
		store.group.Forget(accessKey)
	}
	boundary := identity.RevokedBefore
	if boundary.IsZero() {
		boundary = identity.UpdatedAt
	}
	cleanupCtx := withIAMReplicationTime(ctx, boundary)

	// Membership is derived from the grant and parent revocation versions.
	// Do not rewrite a whole group as a side effect of deleting one member.
	for group, gi := range cache.iamGroupsMap {
		cache.removeGroupFromMembershipsMap(group)
		cache.updateGroupMembershipsMap(group, &gi)
	}
	var cleanupErrors []error
	if userType == regUser {
		for _, users := range []map[string]UserIdentity{cache.iamUsersMap, cache.iamSTSAccountsMap} {
			for key, child := range users {
				if child.Credentials.ParentUser != accessKey || iamCredentialSurvivesRevocation(child.Credentials, boundary) {
					continue
				}
				delete(users, key)
				if store.group != nil {
					store.group.Forget(key)
				}
				// The durable parent boundary suffices for STS. Avoid one
				// permanent tombstone per short-lived random access key.
				if child.Credentials.IsTemp() {
					continue
				}
				if child.Credentials.IsServiceAccount() {
					childCtx, _ := iamChildDeletionContext(cleanupCtx, child)
					if err := store.deleteUserIdentity(childCtx, key, svcUser); err != nil && !errors.Is(err, errIAMStaleUpdate) {
						cleanupErrors = append(cleanupErrors, err)
					}
				}
			}
		}
	}
	// A mapping newer than the revocation is an explicit new grant. Keep it.
	if userType != stsUser {
		// STS policies belong to the parent, not each random token key.
		if err := store.deleteMappedPolicy(cleanupCtx, accessKey, userType, false); err != nil && !errors.Is(err, errIAMStaleUpdate) {
			cleanupErrors = append(cleanupErrors, err)
		}
	}
	if mp, ok := cache.iamUserPolicyMap.Load(accessKey); ok && !mp.UpdatedAt.After(boundary) {
		cache.iamUserPolicyMap.Delete(accessKey)
	}
	if err := errors.Join(cleanupErrors...); err != nil {
		return &iamCommittedCleanupError{err: err, retained: retained}
	}
	if retained {
		return errIAMRevocationRetained
	}
	return nil
}

// SetTempUser - saves temporary (STS) credential to storage and cache. If a
// policy name is given, it is associated with the parent user specified in the
// credential.
func (store *IAMStoreSys) SetTempUser(ctx context.Context, accessKey string, cred auth.Credentials, policyName string) (time.Time, error) {
	if accessKey == "" || !cred.IsTemp() || cred.IsExpired() || cred.ParentUser == "" {
		return time.Time{}, errInvalidArgument
	}

	ttl := int64(cred.Expiration.Sub(UTCNow()).Seconds())

	cache := store.lock()
	defer store.unlock()

	if err := store.checkIAMRevision(ctx, getUserIdentityPath(accessKey, stsUser), false); err != nil {
		return time.Time{}, err
	}
	u := newUserIdentity(cred)
	claims, err := extractJWTClaims(u)
	if err != nil {
		return time.Time{}, err
	}
	u.Credentials.Claims = claims.Map()
	if err := store.checkIAMParentRevision(ctx, u.Credentials); err != nil {
		return time.Time{}, err
	}

	if policyName != "" {
		mp := newMappedPolicy(policyName)
		_, combinedPolicyStmt := filterPolicies(cache, mp.Policies, "")

		if combinedPolicyStmt.IsEmpty() {
			return time.Time{}, fmt.Errorf("specified policy %s, not found %w", policyName, errNoSuchPolicy)
		}

		err := store.saveMappedPolicy(ctx, cred.ParentUser, stsUser, false, &mp, options{ttl: ttl})
		if err != nil {
			return time.Time{}, err
		}

		cache.iamSTSPolicyMap.Store(cred.ParentUser, mp)
	}

	err = store.saveUserIdentity(ctx, accessKey, stsUser, &u, options{ttl: ttl})
	if err != nil {
		return time.Time{}, err
	}

	cache.iamSTSAccountsMap[accessKey] = u
	cache.updatedAt = time.Now()

	return u.UpdatedAt, nil
}

// RevokeTokens - revokes all temporary credentials, or those with matching type,
// associated with the parent user.
func (store *IAMStoreSys) RevokeTokens(ctx context.Context, parentUser string, tokenRevokeType string) error {
	if parentUser == "" {
		return errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	secret, err := getTokenSigningKey()
	if err != nil {
		return err
	}

	var revoked bool
	for _, ui := range cache.iamSTSAccountsMap {
		if ui.Credentials.ParentUser != parentUser {
			continue
		}
		if tokenRevokeType != "" {
			claims, err := getClaimsFromTokenWithSecret(ui.Credentials.SessionToken, secret)
			if err != nil {
				continue // skip if token is invalid
			}
			// skip if token type is given and does not match
			if v, _ := claims.Lookup(tokenRevokeTypeClaim); v != tokenRevokeType {
				continue
			}
		}
		if err := store.deleteUserIdentity(ctx, ui.Credentials.AccessKey, stsUser); err != nil {
			return err
		}
		delete(cache.iamSTSAccountsMap, ui.Credentials.AccessKey)
		revoked = true
	}

	if revoked {
		cache.updatedAt = time.Now()
	}

	return nil
}

// DeleteUsers - given a set of users or access keys, deletes them along with
// any derived credentials (STS or service accounts) and any associated policy
// mappings.
func (store *IAMStoreSys) DeleteUsers(ctx context.Context, users []string) error {
	cache := store.rlock()
	usersToDelete := set.CreateStringSet(users...)
	targets := make(map[string]IAMUserType)
	for _, identities := range []map[string]UserIdentity{cache.iamUsersMap, cache.iamSTSAccountsMap} {
		for key, ui := range identities {
			cred := ui.Credentials
			if !usersToDelete.Contains(key) && !usersToDelete.Contains(cred.ParentUser) {
				continue
			}
			typ := regUser
			if cred.IsServiceAccount() {
				typ = svcUser
			} else if cred.IsTemp() {
				typ = stsUser
			}
			targets[key] = typ
		}
	}
	store.runlock()
	var failures []error
	for key, typ := range targets {
		// External-IDP disablement is an early revocation, not natural token
		// expiration. Preserve the credential's durable ordering boundary.
		if err := store.DeleteUser(ctx, key, typ); err != nil && !errors.Is(err, errIAMRevocationRetained) {
			failures = append(failures, err)
		}
	}
	return errors.Join(failures...)
}

// ParentUserInfo contains extra info about a the parent user.
type ParentUserInfo struct {
	subClaimValue string
	roleArns      set.StringSet
}

// GetAllParentUsers - returns all distinct "parent-users" associated with STS
// or service credentials, mapped to all distinct roleARNs associated with the
// parent user. The dummy role ARN is associated with parent users from
// policy-claim based OpenID providers. The root credential as a parent
// user is not included in the result.
func (store *IAMStoreSys) GetAllParentUsers() map[string]ParentUserInfo {
	cache := store.rlock()
	defer store.runlock()

	return store.getParentUsers(cache)
}

// assumes store is locked by caller.
func (store *IAMStoreSys) getParentUsers(cache *iamCache) map[string]ParentUserInfo {
	res := map[string]ParentUserInfo{}
	for _, ui := range cache.iamUsersMap {
		cred := ui.Credentials
		// Only consider service account or STS credentials with
		// non-empty session tokens.
		if (!cred.IsServiceAccount() && !cred.IsTemp()) ||
			cred.SessionToken == "" {
			continue
		}

		var (
			err    error
			claims *jwt.MapClaims
		)

		if cred.IsServiceAccount() {
			claims, err = getClaimsFromTokenWithSecret(cred.SessionToken, cred.SecretKey)
		} else if cred.IsTemp() {
			var secretKey string
			secretKey, err = getTokenSigningKey()
			if err != nil {
				continue
			}
			claims, err = getClaimsFromTokenWithSecret(cred.SessionToken, secretKey)
		}

		if err != nil {
			continue
		}
		if cred.ParentUser == "" || cred.ParentUser == globalActiveCred.AccessKey {
			continue
		}

		subClaimValue := cred.ParentUser
		if v, ok := claims.Lookup(subClaim); ok {
			subClaimValue = v
		}
		if v, ok := claims.Lookup(ldapActualUser); ok {
			subClaimValue = v
		}

		roleArn := openid.DummyRoleARN.String()
		s, ok := claims.Lookup(roleArnClaim)
		if ok {
			roleArn = s
		}
		v, ok := res[cred.ParentUser]
		if ok {
			res[cred.ParentUser] = ParentUserInfo{
				subClaimValue: subClaimValue,
				roleArns:      v.roleArns.Union(set.CreateStringSet(roleArn)),
			}
		} else {
			res[cred.ParentUser] = ParentUserInfo{
				subClaimValue: subClaimValue,
				roleArns:      set.CreateStringSet(roleArn),
			}
		}
	}

	return res
}

// GetAllSTSUserMappings - Loads all STS user policy mappings from storage and
// returns them. Also gets any STS users that do not have policy mappings but have
// Service Accounts or STS keys (This is useful if the user is part of a group)
func (store *IAMStoreSys) GetAllSTSUserMappings(userPredicate func(string) bool) (map[string]string, error) {
	cache := store.rlock()
	defer store.runlock()

	stsMap := make(map[string]string)
	m := xsync.NewMapOf[string, MappedPolicy]()
	if err := store.loadMappedPolicies(context.Background(), stsUser, false, m); err != nil {
		return nil, err
	}

	m.Range(func(user string, mappedPolicy MappedPolicy) bool {
		if userPredicate != nil && !userPredicate(user) {
			return true
		}
		stsMap[user] = mappedPolicy.Policies
		return true
	})

	for user := range store.getParentUsers(cache) {
		if _, ok := stsMap[user]; !ok {
			if userPredicate != nil && !userPredicate(user) {
				continue
			}
			stsMap[user] = ""
		}
	}
	return stsMap, nil
}

// Assumes store is locked by caller. If userMap is empty, returns all user mappings.
func (store *IAMStoreSys) listUserPolicyMappings(cache *iamCache, userMap map[string]set.StringSet,
	userPredicate func(string) bool, decodeFunc func(string) string,
) []madmin.UserPolicyEntities {
	stsMap := xsync.NewMapOf[string, MappedPolicy]()
	resMap := make(map[string]madmin.UserPolicyEntities, len(userMap))

	for user, groupSet := range userMap {
		// Attempt to load parent user mapping for STS accounts
		store.loadMappedPolicy(context.TODO(), user, stsUser, false, stsMap)
		decodeUser := user
		if decodeFunc != nil {
			decodeUser = decodeFunc(user)
		}
		blankEntities := madmin.UserPolicyEntities{User: decodeUser}
		if !groupSet.IsEmpty() {
			blankEntities.MemberOfMappings = store.listGroupPolicyMappings(cache, groupSet, nil, decodeFunc)
		}
		resMap[user] = blankEntities
	}

	var r []madmin.UserPolicyEntities
	cache.iamUserPolicyMap.Range(func(user string, mappedPolicy MappedPolicy) bool {
		if userPredicate != nil && !userPredicate(user) {
			return true
		}

		entitiesWithMemberOf, ok := resMap[user]
		if !ok {
			if len(userMap) > 0 {
				return true
			}
			decodeUser := user
			if decodeFunc != nil {
				decodeUser = decodeFunc(user)
			}
			entitiesWithMemberOf = madmin.UserPolicyEntities{User: decodeUser}
		}

		ps := mappedPolicy.toSlice()
		sort.Strings(ps)
		entitiesWithMemberOf.Policies = ps
		resMap[user] = entitiesWithMemberOf
		return true
	})

	stsMap.Range(func(user string, mappedPolicy MappedPolicy) bool {
		if userPredicate != nil && !userPredicate(user) {
			return true
		}

		entitiesWithMemberOf := resMap[user]

		ps := mappedPolicy.toSlice()
		sort.Strings(ps)
		entitiesWithMemberOf.Policies = ps
		resMap[user] = entitiesWithMemberOf
		return true
	})

	for _, v := range resMap {
		if v.Policies != nil || v.MemberOfMappings != nil {
			r = append(r, v)
		}
	}

	sort.Slice(r, func(i, j int) bool {
		return r[i].User < r[j].User
	})

	return r
}

// Assumes store is locked by caller. If groups is empty, returns all group mappings.
func (store *IAMStoreSys) listGroupPolicyMappings(cache *iamCache, groupsSet set.StringSet,
	groupPredicate func(string) bool, decodeFunc func(string) string,
) []madmin.GroupPolicyEntities {
	var r []madmin.GroupPolicyEntities

	cache.iamGroupPolicyMap.Range(func(group string, mappedPolicy MappedPolicy) bool {
		if groupPredicate != nil && !groupPredicate(group) {
			return true
		}

		if !groupsSet.IsEmpty() && !groupsSet.Contains(group) {
			return true
		}

		decodeGroup := group
		if decodeFunc != nil {
			decodeGroup = decodeFunc(group)
		}

		ps := mappedPolicy.toSlice()
		sort.Strings(ps)
		r = append(r, madmin.GroupPolicyEntities{
			Group:    decodeGroup,
			Policies: ps,
		})
		return true
	})

	sort.Slice(r, func(i, j int) bool {
		return r[i].Group < r[j].Group
	})

	return r
}

// Assumes store is locked by caller. If policies is empty, returns all policy mappings.
func (store *IAMStoreSys) listPolicyMappings(cache *iamCache, queryPolSet set.StringSet,
	userPredicate, groupPredicate func(string) bool, decodeFunc func(string) string,
) []madmin.PolicyEntities {
	policyToUsersMap := make(map[string]set.StringSet)
	cache.iamUserPolicyMap.Range(func(user string, mappedPolicy MappedPolicy) bool {
		if userPredicate != nil && !userPredicate(user) {
			return true
		}

		decodeUser := user
		if decodeFunc != nil {
			decodeUser = decodeFunc(user)
		}

		commonPolicySet := mappedPolicy.policySet()
		if !queryPolSet.IsEmpty() {
			commonPolicySet = commonPolicySet.Intersection(queryPolSet)
		}
		for _, policy := range commonPolicySet.ToSlice() {
			s, ok := policyToUsersMap[policy]
			if !ok {
				policyToUsersMap[policy] = set.CreateStringSet(decodeUser)
			} else {
				s.Add(decodeUser)
				policyToUsersMap[policy] = s
			}
		}
		return true
	})

	if iamOS, ok := store.IAMStorageAPI.(*IAMObjectStore); ok {
		for item := range listIAMConfigItems(context.Background(), iamOS.objAPI, iamConfigPrefix+SlashSeparator+policyDBSTSUsersListKey) {
			user := strings.TrimSuffix(item.Item, ".json")
			if userPredicate != nil && !userPredicate(user) {
				continue
			}

			decodeUser := user
			if decodeFunc != nil {
				decodeUser = decodeFunc(user)
			}

			var mappedPolicy MappedPolicy
			store.loadIAMConfig(context.Background(), &mappedPolicy, getMappedPolicyPath(user, stsUser, false))

			commonPolicySet := mappedPolicy.policySet()
			if !queryPolSet.IsEmpty() {
				commonPolicySet = commonPolicySet.Intersection(queryPolSet)
			}
			for _, policy := range commonPolicySet.ToSlice() {
				s, ok := policyToUsersMap[policy]
				if !ok {
					policyToUsersMap[policy] = set.CreateStringSet(decodeUser)
				} else {
					s.Add(decodeUser)
					policyToUsersMap[policy] = s
				}
			}
		}
	}
	if iamOS, ok := store.IAMStorageAPI.(*IAMEtcdStore); ok {
		m := xsync.NewMapOf[string, MappedPolicy]()
		err := iamOS.loadMappedPolicies(context.Background(), stsUser, false, m)
		if err == nil {
			m.Range(func(user string, mappedPolicy MappedPolicy) bool {
				if userPredicate != nil && !userPredicate(user) {
					return true
				}

				decodeUser := user
				if decodeFunc != nil {
					decodeUser = decodeFunc(user)
				}

				commonPolicySet := mappedPolicy.policySet()
				if !queryPolSet.IsEmpty() {
					commonPolicySet = commonPolicySet.Intersection(queryPolSet)
				}
				for _, policy := range commonPolicySet.ToSlice() {
					s, ok := policyToUsersMap[policy]
					if !ok {
						policyToUsersMap[policy] = set.CreateStringSet(decodeUser)
					} else {
						s.Add(decodeUser)
						policyToUsersMap[policy] = s
					}
				}
				return true
			})
		}
	}

	policyToGroupsMap := make(map[string]set.StringSet)
	cache.iamGroupPolicyMap.Range(func(group string, mappedPolicy MappedPolicy) bool {
		if groupPredicate != nil && !groupPredicate(group) {
			return true
		}

		decodeGroup := group
		if decodeFunc != nil {
			decodeGroup = decodeFunc(group)
		}

		commonPolicySet := mappedPolicy.policySet()
		if !queryPolSet.IsEmpty() {
			commonPolicySet = commonPolicySet.Intersection(queryPolSet)
		}
		for _, policy := range commonPolicySet.ToSlice() {
			s, ok := policyToGroupsMap[policy]
			if !ok {
				policyToGroupsMap[policy] = set.CreateStringSet(decodeGroup)
			} else {
				s.Add(decodeGroup)
				policyToGroupsMap[policy] = s
			}
		}
		return true
	})

	m := make(map[string]madmin.PolicyEntities, len(policyToGroupsMap))
	for policy, groups := range policyToGroupsMap {
		s := groups.ToSlice()
		sort.Strings(s)
		m[policy] = madmin.PolicyEntities{
			Policy: policy,
			Groups: s,
		}
	}
	for policy, users := range policyToUsersMap {
		s := users.ToSlice()
		sort.Strings(s)

		// Update existing value in map
		pe := m[policy]
		pe.Policy = policy
		pe.Users = s
		m[policy] = pe
	}

	policyEntities := make([]madmin.PolicyEntities, 0, len(m))
	for _, v := range m {
		policyEntities = append(policyEntities, v)
	}

	sort.Slice(policyEntities, func(i, j int) bool {
		return policyEntities[i].Policy < policyEntities[j].Policy
	})

	return policyEntities
}

// ListPolicyMappings - return users/groups mapped to policies.
func (store *IAMStoreSys) ListPolicyMappings(q cleanEntitiesQuery,
	userPredicate, groupPredicate func(string) bool, decodeFunc func(string) string,
) madmin.PolicyEntitiesResult {
	cache := store.rlock()
	defer store.runlock()

	var result madmin.PolicyEntitiesResult

	isAllPoliciesQuery := len(q.Users) == 0 && len(q.Groups) == 0 && len(q.Policies) == 0

	if len(q.Users) > 0 {
		result.UserMappings = store.listUserPolicyMappings(cache, q.Users, userPredicate, decodeFunc)
	}
	if len(q.Groups) > 0 {
		result.GroupMappings = store.listGroupPolicyMappings(cache, q.Groups, groupPredicate, decodeFunc)
	}
	if len(q.Policies) > 0 || isAllPoliciesQuery {
		result.PolicyMappings = store.listPolicyMappings(cache, q.Policies, userPredicate, groupPredicate, decodeFunc)
	}
	return result
}

// SetUserStatus - sets current user status.
func (store *IAMStoreSys) SetUserStatus(ctx context.Context, accessKey string, status madmin.AccountStatus) (updatedAt time.Time, err error) {
	if accessKey != "" && status != madmin.AccountEnabled && status != madmin.AccountDisabled {
		return updatedAt, errInvalidArgument
	}

	cache := store.lock()
	defer store.unlock()

	ui, ok := cache.iamUsersMap[accessKey]
	if !ok {
		return updatedAt, errNoSuchUser
	}
	cred := ui.Credentials

	if cred.IsTemp() || cred.IsServiceAccount() {
		return updatedAt, errIAMActionNotAllowed
	}

	uinfo := newUserIdentity(auth.Credentials{
		AccessKey: accessKey,
		SecretKey: cred.SecretKey,
		Status: func() string {
			switch string(status) {
			case string(madmin.AccountEnabled), string(auth.AccountOn):
				return auth.AccountOn
			}
			return auth.AccountOff
		}(),
	})

	if err := store.saveUserIdentity(ctx, accessKey, regUser, &uinfo); err != nil {
		return updatedAt, err
	}

	if err := cache.updateUserWithClaims(accessKey, uinfo); err != nil {
		return updatedAt, err
	}

	return uinfo.UpdatedAt, nil
}

// AddServiceAccount - add a new service account
func (store *IAMStoreSys) AddServiceAccount(ctx context.Context, cred auth.Credentials) (updatedAt time.Time, err error) {
	cache := store.lock()
	defer store.unlock()

	accessKey := cred.AccessKey
	parentUser := cred.ParentUser

	// Local creates cannot replace an existing key. Replication also sends
	// full snapshots after deletion/recreation, possibly with a new owner;
	// their source revision is compared atomically by saveUserIdentity.
	_, replicated := iamReplicationTime(ctx)
	if su, found := cache.iamUsersMap[accessKey]; found {
		scred := su.Credentials
		if !replicated || !scred.IsServiceAccount() {
			if scred.ParentUser != parentUser {
				return updatedAt, fmt.Errorf("%w: the service account access key is taken by another user", errIAMServiceAccountNotAllowed)
			}
			return updatedAt, fmt.Errorf("%w: the service account access key already taken", errIAMServiceAccountNotAllowed)
		}
	}
	if _, found := cache.iamSTSAccountsMap[accessKey]; found {
		return updatedAt, fmt.Errorf("%w: the service account access key is taken by a temporary credential", errIAMServiceAccountNotAllowed)
	}

	// Parent user must not be a service account.
	if u, found := cache.iamUsersMap[parentUser]; found && u.Credentials.IsServiceAccount() {
		return updatedAt, fmt.Errorf("%w: unable to create a service account for another service account", errIAMServiceAccountNotAllowed)
	}

	u := newUserIdentity(cred)
	err = store.saveUserIdentity(ctx, u.Credentials.AccessKey, svcUser, &u)
	if err != nil {
		return updatedAt, err
	}

	if err := cache.updateUserWithClaims(u.Credentials.AccessKey, u); err != nil {
		// Persistence already replaced the credential. A failed refresh must
		// not leave its superseded secret usable through this node's cache.
		delete(cache.iamUsersMap, accessKey)
		cache.updatedAt = UTCNow()
		return updatedAt, err
	}

	return u.UpdatedAt, nil
}

// UpdateServiceAccount - updates a service account on storage.
func (store *IAMStoreSys) UpdateServiceAccount(ctx context.Context, accessKey string, opts updateServiceAccountOpts) (updatedAt time.Time, err error) {
	cache := store.lock()
	defer store.unlock()

	ui, ok := cache.iamUsersMap[accessKey]
	if !ok || !ui.Credentials.IsServiceAccount() {
		return updatedAt, errNoSuchServiceAccount
	}
	cr := ui.Credentials
	currentSecretKey := cr.SecretKey
	if opts.secretKey != "" {
		if !auth.IsSecretKeyValid(opts.secretKey) {
			return updatedAt, auth.ErrInvalidSecretKeyLength
		}
		cr.SecretKey = opts.secretKey
	}

	if opts.name != "" {
		cr.Name = opts.name
	}

	if opts.description != "" {
		cr.Description = opts.description
	}

	if opts.expiration != nil {
		expirationInUTC := opts.expiration.UTC()
		if err := validateSvcExpirationInUTC(ctx, expirationInUTC); err != nil {
			return updatedAt, err
		}
		cr.Expiration = expirationInUTC
	}

	switch opts.status {
	// The caller did not ask to update status account, do nothing
	case "":
	case string(madmin.AccountEnabled):
		cr.Status = auth.AccountOn
	case string(madmin.AccountDisabled):
		cr.Status = auth.AccountOff
	// Update account status
	case auth.AccountOn, auth.AccountOff:
		cr.Status = opts.status
	default:
		return updatedAt, errors.New("unknown account status value")
	}

	m, err := getClaimsFromTokenWithSecret(cr.SessionToken, currentSecretKey)
	if err != nil {
		return updatedAt, fmt.Errorf("unable to get svc acc claims: %v", err)
	}

	// Extracted session policy name string can be removed as its not useful
	// at this point.
	m.Delete(sessionPolicyNameExtracted)

	nosp := opts.sessionPolicy == nil || opts.sessionPolicy.Version == "" && len(opts.sessionPolicy.Statements) == 0

	// sessionPolicy is nil and there is embedded policy attached we remove
	// embedded policy at that point.
	if _, ok := m.Lookup(policy.SessionPolicyName); ok && nosp {
		m.Delete(policy.SessionPolicyName)
		m.Set(iamPolicyClaimNameSA(), inheritedPolicyType)
	}

	if opts.sessionPolicy != nil { // session policies is being updated
		if err := opts.sessionPolicy.Validate(); err != nil {
			return updatedAt, err
		}

		if opts.sessionPolicy.Version != "" && len(opts.sessionPolicy.Statements) > 0 {
			policyBuf, err := json.Marshal(opts.sessionPolicy)
			if err != nil {
				return updatedAt, err
			}

			if len(policyBuf) > maxSVCSessionPolicySize {
				return updatedAt, errSessionPolicyTooLarge
			}

			// Overwrite session policy claims.
			m.Set(policy.SessionPolicyName, base64.StdEncoding.EncodeToString(policyBuf))
			m.Set(iamPolicyClaimNameSA(), embeddedPolicyType)
		}
	}

	cr.SessionToken, err = auth.JWTSignWithAccessKey(accessKey, m.Map(), cr.SecretKey)
	if err != nil {
		return updatedAt, err
	}

	u := newUserIdentity(cr)
	if err := store.saveUserIdentity(ctx, u.Credentials.AccessKey, svcUser, &u); err != nil {
		return updatedAt, err
	}

	if err := cache.updateUserWithClaims(u.Credentials.AccessKey, u); err != nil {
		delete(cache.iamUsersMap, accessKey)
		cache.updatedAt = UTCNow()
		return updatedAt, err
	}

	return u.UpdatedAt, nil
}

// ListTempAccounts - lists only temporary accounts from the cache.
func (store *IAMStoreSys) ListTempAccounts(ctx context.Context, accessKey string) ([]UserIdentity, error) {
	cache := store.rlock()
	defer store.runlock()

	userExists := false
	var tempAccounts []UserIdentity
	for _, v := range cache.iamUsersMap {
		isDerived := false
		if v.Credentials.IsServiceAccount() || v.Credentials.IsTemp() {
			isDerived = true
		}

		if !isDerived && v.Credentials.AccessKey == accessKey {
			userExists = true
		} else if isDerived && v.Credentials.ParentUser == accessKey {
			userExists = true
			if v.Credentials.IsTemp() {
				// Hide secret key & session key here
				v.Credentials.SecretKey = ""
				v.Credentials.SessionToken = ""
				tempAccounts = append(tempAccounts, v)
			}
		}
	}

	if !userExists {
		return nil, errNoSuchUser
	}

	return tempAccounts, nil
}

// ListServiceAccounts - lists only service accounts from the cache.
func (store *IAMStoreSys) ListServiceAccounts(ctx context.Context, accessKey string) ([]auth.Credentials, error) {
	cache := store.rlock()
	defer store.runlock()

	var serviceAccounts []auth.Credentials
	for _, u := range cache.iamUsersMap {
		v := u.Credentials
		if accessKey != "" && v.ParentUser == accessKey {
			if v.IsServiceAccount() {
				// Hide secret key & session key here
				v.SecretKey = ""
				v.SessionToken = ""
				serviceAccounts = append(serviceAccounts, v)
			}
		}
	}

	return serviceAccounts, nil
}

// ListSTSAccounts - lists only STS accounts from the cache.
func (store *IAMStoreSys) ListSTSAccounts(ctx context.Context, accessKey string) ([]auth.Credentials, error) {
	cache := store.rlock()
	defer store.runlock()

	var stsAccounts []auth.Credentials
	for _, u := range cache.iamSTSAccountsMap {
		v := u.Credentials
		if accessKey != "" && v.ParentUser == accessKey {
			if v.IsTemp() {
				// Hide secret key & session key here
				v.SecretKey = ""
				v.SessionToken = ""
				stsAccounts = append(stsAccounts, v)
			}
		}
	}

	return stsAccounts, nil
}

// ListAccessKeys - lists all access keys (sts/service accounts)
func (store *IAMStoreSys) ListAccessKeys(ctx context.Context) ([]auth.Credentials, error) {
	cache := store.rlock()
	defer store.runlock()

	accessKeys := store.getSTSAndServiceAccounts(cache)
	for i, accessKey := range accessKeys {
		accessKeys[i].SecretKey = ""
		if accessKey.IsTemp() {
			secret, err := getTokenSigningKey()
			if err != nil {
				return nil, err
			}
			claims, err := getClaimsFromTokenWithSecret(accessKey.SessionToken, secret)
			if err != nil {
				continue // ignore invalid session tokens
			}
			accessKeys[i].Claims = claims.MapClaims
		}
		accessKeys[i].SessionToken = ""
	}

	return accessKeys, nil
}

// AddUser - adds/updates long term user account to storage.
func (store *IAMStoreSys) AddUser(ctx context.Context, accessKey string, ureq madmin.AddOrUpdateUserReq) (updatedAt time.Time, err error) {
	cache := store.lock()
	defer store.unlock()

	cache.updatedAt = time.Now()

	ui, ok := cache.iamUsersMap[accessKey]

	// It is not possible to update an STS account.
	if ok && ui.Credentials.IsTemp() {
		return updatedAt, errIAMActionNotAllowed
	}

	u := newUserIdentity(auth.Credentials{
		AccessKey: accessKey,
		SecretKey: ureq.SecretKey,
		Status: func() string {
			switch string(ureq.Status) {
			case string(madmin.AccountEnabled), string(auth.AccountOn):
				return auth.AccountOn
			}
			return auth.AccountOff
		}(),
	})

	if err := store.saveUserIdentity(ctx, accessKey, regUser, &u); err != nil {
		return updatedAt, err
	}
	if err := cache.updateUserWithClaims(accessKey, u); err != nil {
		return updatedAt, err
	}

	return u.UpdatedAt, nil
}

// UpdateUserSecretKey - sets user secret key to storage.
func (store *IAMStoreSys) UpdateUserSecretKey(ctx context.Context, accessKey, secretKey string) error {
	cache := store.lock()
	defer store.unlock()

	cache.updatedAt = time.Now()

	ui, ok := cache.iamUsersMap[accessKey]
	if !ok {
		return errNoSuchUser
	}
	cred := ui.Credentials
	cred.SecretKey = secretKey
	u := newUserIdentity(cred)
	if err := store.saveUserIdentity(ctx, accessKey, regUser, &u); err != nil {
		return err
	}

	return cache.updateUserWithClaims(accessKey, u)
}

// GetSTSAndServiceAccounts - returns all STS and Service account credentials.
func (store *IAMStoreSys) GetSTSAndServiceAccounts() []auth.Credentials {
	cache := store.rlock()
	defer store.runlock()

	return store.getSTSAndServiceAccounts(cache)
}

func (store *IAMStoreSys) getSTSAndServiceAccounts(cache *iamCache) []auth.Credentials {
	var res []auth.Credentials
	for _, u := range cache.iamUsersMap {
		cred := u.Credentials
		if cred.IsServiceAccount() {
			res = append(res, cred)
		}
	}
	for _, u := range cache.iamSTSAccountsMap {
		res = append(res, u.Credentials)
	}

	return res
}

// UpdateUserIdentity - updates a user credential.
func (store *IAMStoreSys) UpdateUserIdentity(ctx context.Context, cred auth.Credentials) error {
	cache := store.lock()
	defer store.unlock()

	cache.updatedAt = time.Now()

	userType := regUser
	if cred.IsServiceAccount() {
		userType = svcUser
	} else if cred.IsTemp() {
		userType = stsUser
	}
	ui := newUserIdentity(cred)
	// Overwrite the user identity here. As store should be
	// atomic, it shouldn't cause any corruption.
	if err := store.saveUserIdentity(ctx, cred.AccessKey, userType, &ui); err != nil {
		return err
	}

	return cache.updateUserWithClaims(cred.AccessKey, ui)
}

// LoadUser - attempts to load user info from storage and updates cache.
func (store *IAMStoreSys) LoadUser(ctx context.Context, accessKey string) error {
	groupLoad := env.Get("_MINIO_IAM_GROUP_REFRESH", config.EnableOff) == config.EnableOn

	newCachePopulate := func() (val any, err error) {
		newCache := newIamCache()
		newCache.revisions = store.revisionIndex()

		// Check for service account first
		store.loadUser(ctx, accessKey, svcUser, newCache.iamUsersMap)

		svc, found := newCache.iamUsersMap[accessKey]
		if found {
			// Load parent user and mapped policies.
			if store.getUsersSysType() == MinIOUsersSysType {
				err = store.loadUser(ctx, svc.Credentials.ParentUser, regUser, newCache.iamUsersMap)
				// NOTE: we are not worried about loading errors from policies.
				store.loadMappedPolicyWithRetry(ctx, svc.Credentials.ParentUser, regUser, false, newCache.iamUserPolicyMap, 3)
			} else {
				// In case of LDAP the parent user's policy mapping needs to be loaded into sts map
				// NOTE: we are not worried about loading errors from policies.
				store.loadMappedPolicyWithRetry(ctx, svc.Credentials.ParentUser, stsUser, false, newCache.iamSTSPolicyMap, 3)
			}
		}

		if !found {
			err = store.loadUser(ctx, accessKey, regUser, newCache.iamUsersMap)
			if _, found = newCache.iamUsersMap[accessKey]; found {
				// NOTE: we are not worried about loading errors from policies.
				store.loadMappedPolicyWithRetry(ctx, accessKey, regUser, false, newCache.iamUserPolicyMap, 3)
			}
		}

		// Check for STS account
		var stsUserCred UserIdentity
		if !found {
			err = store.loadUser(ctx, accessKey, stsUser, newCache.iamSTSAccountsMap)
			if stsUserCred, found = newCache.iamSTSAccountsMap[accessKey]; found {
				// Load mapped policy
				// NOTE: we are not worried about loading errors from policies.
				store.loadMappedPolicyWithRetry(ctx, stsUserCred.Credentials.ParentUser, stsUser, false, newCache.iamSTSPolicyMap, 3)
			}
		}

		// Load any associated policy definitions
		pols, _ := newCache.iamUserPolicyMap.Load(accessKey)
		for _, policy := range pols.toSlice() {
			if _, found = newCache.iamPolicyDocsMap[policy]; !found {
				// NOTE: we are not worried about loading errors from policies.
				store.loadPolicyDocWithRetry(ctx, policy, newCache.iamPolicyDocsMap, 3)
			}
		}

		pols, _ = newCache.iamSTSPolicyMap.Load(stsUserCred.Credentials.AccessKey)
		for _, policy := range pols.toSlice() {
			if _, found = newCache.iamPolicyDocsMap[policy]; !found {
				// NOTE: we are not worried about loading errors from policies.
				store.loadPolicyDocWithRetry(ctx, policy, newCache.iamPolicyDocsMap, 3)
			}
		}

		if groupLoad {
			// NOTE: we are not worried about loading errors from groups.
			store.updateGroups(ctx, newCache)
			newCache.buildUserGroupMemberships()
		}

		return newCache, err
	}

	var (
		val any
		err error
	)
	if store.group != nil {
		val, err, _ = store.group.Do(accessKey, newCachePopulate)
	} else {
		val, err = newCachePopulate()
	}

	// Return error right away if any.
	if err != nil {
		if errors.Is(err, errNoSuchUser) || errors.Is(err, errConfigNotFound) {
			return nil
		}
		return err
	}

	newCache, ok := val.(*iamCache)
	if !ok {
		return nil
	}

	cache := store.lock()
	defer store.unlock()

	// We need to merge the new cache with the existing cache because the
	// periodic IAM reload is partial. The periodic load here is to account.
	newCache.iamGroupPolicyMap.Range(func(k string, v MappedPolicy) bool {
		cache.iamGroupPolicyMap.Store(k, v)
		return true
	})

	maps.Copy(cache.iamGroupsMap, newCache.iamGroupsMap)

	maps.Copy(cache.iamPolicyDocsMap, newCache.iamPolicyDocsMap)

	maps.Copy(cache.iamUserGroupMemberships, newCache.iamUserGroupMemberships)

	newCache.iamUserPolicyMap.Range(func(k string, v MappedPolicy) bool {
		cache.iamUserPolicyMap.Store(k, v)
		return true
	})

	maps.Copy(cache.iamUsersMap, newCache.iamUsersMap)

	maps.Copy(cache.iamSTSAccountsMap, newCache.iamSTSAccountsMap)

	newCache.iamSTSPolicyMap.Range(func(k string, v MappedPolicy) bool {
		cache.iamSTSPolicyMap.Store(k, v)
		return true
	})

	cache.updatedAt = time.Now()

	return nil
}

func extractJWTClaims(u UserIdentity) (jwtClaims *jwt.MapClaims, err error) {
	keys := make([]string, 0, 3)

	// Append credentials secret key itself
	keys = append(keys, u.Credentials.SecretKey)

	// Use site-replication credentials if found
	if globalSiteReplicationSys.isEnabled() {
		secretKey, err := getTokenSigningKey()
		if err != nil {
			return nil, err
		}
		keys = append(keys, secretKey)
	}

	// Iterate over all keys and return with the first successful claim extraction
	for _, key := range keys {
		jwtClaims, err = getClaimsFromTokenWithSecret(u.Credentials.SessionToken, key)
		if err == nil {
			break
		}
	}
	return jwtClaims, err
}

func validateSvcExpirationInUTC(ctx context.Context, expirationInUTC time.Time) error {
	if _, replicated := iamReplicationTime(ctx); replicated {
		// Issuance limits were checked at the source. Keep its absolute
		// expiration, even if it has passed: persisting the newer expired
		// identity denies the older credential and lets ordinary cleanup
		// retain a tombstone. Rejecting it could leave an old key alive.
		return nil
	}
	if expirationInUTC.IsZero() || expirationInUTC.Equal(timeSentinel) {
		// Service accounts might not have expiration in older releases.
		return nil
	}

	currentTime := time.Now().UTC()
	minExpiration := currentTime.Add(minServiceAccountExpiry)
	maxExpiration := currentTime.Add(maxServiceAccountExpiry)
	if expirationInUTC.Before(minExpiration) || expirationInUTC.After(maxExpiration) {
		return errInvalidSvcAcctExpiration
	}

	return nil
}