/*
 * Minio Cloud Storage, (C) 2016, 2017, 2018 Minio, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cmd

import (
	"archive/zip"
	"bytes"
	"context"
	"encoding/base64"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"os"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/gorilla/mux"
	"github.com/minio/minio/cmd/logger"
	"github.com/minio/minio/pkg/auth"
	"github.com/minio/minio/pkg/handlers"
	"github.com/minio/minio/pkg/iam/policy"
	"github.com/minio/minio/pkg/madmin"
	"github.com/minio/minio/pkg/quick"
	"github.com/tidwall/gjson"
	"github.com/tidwall/sjson"
)

const (
	maxEConfigJSONSize = 262272
)

// Type-safe query params.
type mgmtQueryKey string

// Only valid query params for mgmt admin APIs.
const (
	mgmtBucket      mgmtQueryKey = "bucket"
	mgmtPrefix      mgmtQueryKey = "prefix"
	mgmtClientToken mgmtQueryKey = "clientToken"
	mgmtForceStart  mgmtQueryKey = "forceStart"
)

var (
	// This struct literal represents the Admin API version that
	// the server uses.
	adminAPIVersionInfo = madmin.AdminAPIVersionInfo{
		Version: "1",
	}
)

// VersionHandler - GET /minio/admin/version
// -----------
// Returns Administration API version
func (a adminAPIHandlers) VersionHandler(w http.ResponseWriter, r *http.Request) {
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	jsonBytes, err := json.Marshal(adminAPIVersionInfo)
	if err != nil {
		writeErrorResponseJSON(w, ErrInternalError, r.URL)
		logger.LogIf(context.Background(), err)
		return
	}

	writeSuccessResponseJSON(w, jsonBytes)
}

// ServiceStatusHandler - GET /minio/admin/v1/service
// ----------
// Returns server version and uptime.
func (a adminAPIHandlers) ServiceStatusHandler(w http.ResponseWriter, r *http.Request) {
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	// Fetch server version
	serverVersion := madmin.ServerVersion{
		Version:  Version,
		CommitID: CommitID,
	}

	// Fetch uptimes from all peers. This may fail to due to lack
	// of read-quorum availability.
	uptime, err := getPeerUptimes(globalAdminPeers)
	if err != nil {
		writeErrorResponseJSON(w, toAPIErrorCode(err), r.URL)
		logger.LogIf(context.Background(), err)
		return
	}

	// Create API response
	serverStatus := madmin.ServiceStatus{
		ServerVersion: serverVersion,
		Uptime:        uptime,
	}

	// Marshal API response
	jsonBytes, err := json.Marshal(serverStatus)
	if err != nil {
		writeErrorResponseJSON(w, ErrInternalError, r.URL)
		logger.LogIf(context.Background(), err)
		return
	}
	// Reply with storage information (across nodes in a
	// distributed setup) as json.
	writeSuccessResponseJSON(w, jsonBytes)
}

// ServiceStopNRestartHandler - POST /minio/admin/v1/service
// Body: {"action": <restart-action>}
// ----------
// Restarts/Stops minio server gracefully. In a distributed setup,
// restarts all the servers in the cluster.
func (a adminAPIHandlers) ServiceStopNRestartHandler(w http.ResponseWriter, r *http.Request) {
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	var sa madmin.ServiceAction
	err := json.NewDecoder(r.Body).Decode(&sa)
	if err != nil {
		logger.LogIf(context.Background(), err)
		writeErrorResponseJSON(w, ErrRequestBodyParse, r.URL)
		return
	}

	var serviceSig serviceSignal
	switch sa.Action {
	case madmin.ServiceActionValueRestart:
		serviceSig = serviceRestart
	case madmin.ServiceActionValueStop:
		serviceSig = serviceStop
	default:
		writeErrorResponseJSON(w, ErrMalformedPOSTRequest, r.URL)
		logger.LogIf(context.Background(), errors.New("Invalid service action received"))
		return
	}

	// Reply to the client before restarting minio server.
	writeSuccessResponseHeadersOnly(w)

	sendServiceCmd(globalAdminPeers, serviceSig)
}

// ServerProperties holds some server information such as, version, region
// uptime, etc..
type ServerProperties struct {
	Uptime   time.Duration `json:"uptime"`
	Version  string        `json:"version"`
	CommitID string        `json:"commitID"`
	Region   string        `json:"region"`
	SQSARN   []string      `json:"sqsARN"`
}

// ServerConnStats holds transferred bytes from/to the server
type ServerConnStats struct {
	TotalInputBytes  uint64 `json:"transferred"`
	TotalOutputBytes uint64 `json:"received"`
	Throughput       uint64 `json:"throughput,omitempty"`
}

// ServerHTTPMethodStats holds total number of HTTP operations from/to the server,
// including the average duration the call was spent.
type ServerHTTPMethodStats struct {
	Count       uint64 `json:"count"`
	AvgDuration string `json:"avgDuration"`
}

// ServerHTTPStats holds all type of http operations performed to/from the server
// including their average execution time.
type ServerHTTPStats struct {
	TotalHEADStats     ServerHTTPMethodStats `json:"totalHEADs"`
	SuccessHEADStats   ServerHTTPMethodStats `json:"successHEADs"`
	TotalGETStats      ServerHTTPMethodStats `json:"totalGETs"`
	SuccessGETStats    ServerHTTPMethodStats `json:"successGETs"`
	TotalPUTStats      ServerHTTPMethodStats `json:"totalPUTs"`
	SuccessPUTStats    ServerHTTPMethodStats `json:"successPUTs"`
	TotalPOSTStats     ServerHTTPMethodStats `json:"totalPOSTs"`
	SuccessPOSTStats   ServerHTTPMethodStats `json:"successPOSTs"`
	TotalDELETEStats   ServerHTTPMethodStats `json:"totalDELETEs"`
	SuccessDELETEStats ServerHTTPMethodStats `json:"successDELETEs"`
}

// ServerInfoData holds storage, connections and other
// information of a given server.
type ServerInfoData struct {
	StorageInfo StorageInfo      `json:"storage"`
	ConnStats   ServerConnStats  `json:"network"`
	HTTPStats   ServerHTTPStats  `json:"http"`
	Properties  ServerProperties `json:"server"`
}

// ServerInfo holds server information result of one node
type ServerInfo struct {
	Error string          `json:"error"`
	Addr  string          `json:"addr"`
	Data  *ServerInfoData `json:"data"`
}

// ServerInfoHandler - GET /minio/admin/v1/info
// ----------
// Get server information
func (a adminAPIHandlers) ServerInfoHandler(w http.ResponseWriter, r *http.Request) {
	// Authenticate request

	// Setting the region as empty so as the mc server info command is irrespective to the region.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	// Web service response
	reply := make([]ServerInfo, len(globalAdminPeers))

	var wg sync.WaitGroup

	// Gather server information for all nodes
	for i, p := range globalAdminPeers {
		wg.Add(1)

		// Gather information from a peer in a goroutine
		go func(idx int, peer adminPeer) {
			defer wg.Done()

			// Initialize server info at index
			reply[idx] = ServerInfo{Addr: peer.addr}

			serverInfoData, err := peer.cmdRunner.ServerInfo()
			if err != nil {
				reqInfo := (&logger.ReqInfo{}).AppendTags("peerAddress", peer.addr)
				ctx := logger.SetReqInfo(context.Background(), reqInfo)
				logger.LogIf(ctx, err)
				reply[idx].Error = err.Error()
				return
			}

			reply[idx].Data = &serverInfoData
		}(i, p)
	}

	wg.Wait()

	// Marshal API response
	jsonBytes, err := json.Marshal(reply)
	if err != nil {
		writeErrorResponseJSON(w, ErrInternalError, r.URL)
		logger.LogIf(context.Background(), err)
		return
	}

	// Reply with storage information (across nodes in a
	// distributed setup) as json.
	writeSuccessResponseJSON(w, jsonBytes)
}

// StartProfilingResult contains the status of the starting
// profiling action in a given server
type StartProfilingResult struct {
	NodeName string `json:"nodeName"`
	Success  bool   `json:"success"`
	Error    string `json:"error"`
}

// StartProfilingHandler - POST /minio/admin/v1/profiling/start?profilerType={profilerType}
// ----------
// Enable server profiling
func (a adminAPIHandlers) StartProfilingHandler(w http.ResponseWriter, r *http.Request) {
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	vars := mux.Vars(r)
	profiler := vars["profilerType"]

	startProfilingResult := make([]StartProfilingResult, len(globalAdminPeers))

	// Call StartProfiling function on all nodes and save results
	wg := sync.WaitGroup{}
	for i, peer := range globalAdminPeers {
		wg.Add(1)
		go func(idx int, peer adminPeer) {
			defer wg.Done()
			result := StartProfilingResult{NodeName: peer.addr}
			if err := peer.cmdRunner.StartProfiling(profiler); err != nil {
				result.Error = err.Error()
				return
			}
			result.Success = true
			startProfilingResult[idx] = result
		}(i, peer)
	}
	wg.Wait()

	// Create JSON result and send it to the client
	startProfilingResultInBytes, err := json.Marshal(startProfilingResult)
	if err != nil {
		writeCustomErrorResponseJSON(w, http.StatusInternalServerError, err.Error(), r.URL)
		return
	}
	writeSuccessResponseJSON(w, []byte(startProfilingResultInBytes))
}

// dummyFileInfo represents a dummy representation of a profile data file
// present only in memory, it helps to generate the zip stream.
type dummyFileInfo struct {
	name    string
	size    int64
	mode    os.FileMode
	modTime time.Time
	isDir   bool
	sys     interface{}
}

func (f dummyFileInfo) Name() string       { return f.name }
func (f dummyFileInfo) Size() int64        { return f.size }
func (f dummyFileInfo) Mode() os.FileMode  { return f.mode }
func (f dummyFileInfo) ModTime() time.Time { return f.modTime }
func (f dummyFileInfo) IsDir() bool        { return f.isDir }
func (f dummyFileInfo) Sys() interface{}   { return f.sys }

// DownloadProfilingHandler - POST /minio/admin/v1/profiling/download
// ----------
// Download profiling information of all nodes in a zip format
func (a adminAPIHandlers) DownloadProfilingHandler(w http.ResponseWriter, r *http.Request) {
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	profilingDataFound := false

	// Initialize a zip writer which will provide a zipped content
	// of profiling data of all nodes
	zipWriter := zip.NewWriter(w)
	defer zipWriter.Close()

	for i, peer := range globalAdminPeers {
		// Get profiling data from a node
		data, err := peer.cmdRunner.DownloadProfilingData()
		if err != nil {
			logger.LogIf(context.Background(), fmt.Errorf("Unable to download profiling data from node `%s`, reason: %s", peer.addr, err.Error()))
			continue
		}

		profilingDataFound = true

		// Send profiling data to zip as file
		header, err := zip.FileInfoHeader(dummyFileInfo{
			name:    fmt.Sprintf("profiling-%d", i),
			size:    int64(len(data)),
			mode:    0600,
			modTime: time.Now().UTC(),
			isDir:   false,
			sys:     nil,
		})
		if err != nil {
			continue
		}
		writer, err := zipWriter.CreateHeader(header)
		if err != nil {
			continue
		}
		if _, err = io.Copy(writer, bytes.NewBuffer(data)); err != nil {
			return
		}
	}

	if !profilingDataFound {
		writeErrorResponseJSON(w, ErrAdminProfilerNotEnabled, r.URL)
		return
	}
}

// extractHealInitParams - Validates params for heal init API.
func extractHealInitParams(r *http.Request) (bucket, objPrefix string,
	hs madmin.HealOpts, clientToken string, forceStart bool,
	err APIErrorCode) {

	vars := mux.Vars(r)
	bucket = vars[string(mgmtBucket)]
	objPrefix = vars[string(mgmtPrefix)]

	if bucket == "" {
		if objPrefix != "" {
			// Bucket is required if object-prefix is given
			err = ErrHealMissingBucket
			return
		}
	} else if !IsValidBucketName(bucket) {
		err = ErrInvalidBucketName
		return
	}

	// empty prefix is valid.
	if !IsValidObjectPrefix(objPrefix) {
		err = ErrInvalidObjectName
		return
	}

	qParms := r.URL.Query()
	if len(qParms[string(mgmtClientToken)]) > 0 {
		clientToken = qParms[string(mgmtClientToken)][0]
	}
	if _, ok := qParms[string(mgmtForceStart)]; ok {
		forceStart = true
	}

	// ignore body if clientToken is provided
	if clientToken == "" {
		jerr := json.NewDecoder(r.Body).Decode(&hs)
		if jerr != nil {
			logger.LogIf(context.Background(), jerr)
			err = ErrRequestBodyParse
			return
		}
	}

	err = ErrNone
	return
}

// HealHandler - POST /minio/admin/v1/heal/
// -----------
// Start heal processing and return heal status items.
//
// On a successful heal sequence start, a unique client token is
// returned. Subsequent requests to this endpoint providing the client
// token will receive heal status records from the running heal
// sequence.
//
// If no client token is provided, and a heal sequence is in progress
// an error is returned with information about the running heal
// sequence. However, if the force-start flag is provided, the server
// aborts the running heal sequence and starts a new one.
func (a adminAPIHandlers) HealHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "Heal")

	// Get object layer instance.
	objLayer := newObjectLayerFn()
	if objLayer == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	// Check if this setup has an erasure coded backend.
	if !globalIsXL {
		writeErrorResponseJSON(w, ErrHealNotImplemented, r.URL)
		return
	}

	bucket, objPrefix, hs, clientToken, forceStart, apiErr := extractHealInitParams(r)
	if apiErr != ErrNone {
		writeErrorResponseJSON(w, apiErr, r.URL)
		return
	}

	type healResp struct {
		respBytes []byte
		errCode   APIErrorCode
		errBody   string
	}

	// Define a closure to start sending whitespace to client
	// after 10s unless a response item comes in
	keepConnLive := func(w http.ResponseWriter, respCh chan healResp) {
		ticker := time.NewTicker(time.Second * 10)
		defer ticker.Stop()
		started := false
	forLoop:
		for {
			select {
			case <-ticker.C:
				if !started {
					// Start writing response to client
					started = true
					setCommonHeaders(w)
					w.Header().Set("Content-Type", string(mimeJSON))
					// Set 200 OK status
					w.WriteHeader(200)
				}
				// Send whitespace and keep connection open
				w.Write([]byte("\n\r"))
				w.(http.Flusher).Flush()
			case hr := <-respCh:
				switch {
				case hr.errCode == ErrNone:
					writeSuccessResponseJSON(w, hr.respBytes)
				case hr.errBody == "":
					writeErrorResponseJSON(w, hr.errCode, r.URL)
				default:
					writeCustomErrorResponseJSON(w, hr.errCode, hr.errBody, r.URL)
				}
				break forLoop
			}
		}
	}

	// find number of disks in the setup
	info := objLayer.StorageInfo(ctx)
	numDisks := info.Backend.OfflineDisks + info.Backend.OnlineDisks

	if clientToken == "" {
		// Not a status request
		nh := newHealSequence(bucket, objPrefix, handlers.GetSourceIP(r),
			numDisks, hs, forceStart)

		respCh := make(chan healResp)
		go func() {
			respBytes, errCode, errMsg := globalAllHealState.LaunchNewHealSequence(nh)
			hr := healResp{respBytes, errCode, errMsg}
			respCh <- hr
		}()

		// Due to the force-starting functionality, the Launch
		// call above can take a long time - to keep the
		// connection alive, we start sending whitespace
		keepConnLive(w, respCh)
	} else {
		// Since clientToken is given, fetch heal status from running
		// heal sequence.
		path := bucket + "/" + objPrefix
		respBytes, errCode := globalAllHealState.PopHealStatusJSON(
			path, clientToken)
		if errCode != ErrNone {
			writeErrorResponseJSON(w, errCode, r.URL)
		} else {
			writeSuccessResponseJSON(w, respBytes)
		}
	}
}

// GetConfigHandler - GET /minio/admin/v1/config
// Get config.json of this minio setup.
func (a adminAPIHandlers) GetConfigHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "GetConfigHandler")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	config, err := readServerConfig(ctx, objectAPI)
	if err != nil {
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	configData, err := json.MarshalIndent(config, "", "\t")
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	password := config.GetCredential().SecretKey
	econfigData, err := madmin.EncryptData(password, configData)
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	writeSuccessResponseJSON(w, econfigData)
}

// Disable tidwall json array notation in JSON key path so
// users can set json with a key as a number.
// In tidwall json, notify.webhook.0 = val means { "notify" : { "webhook" : [val] }}
// In Minio, notify.webhook.0 = val means { "notify" : { "webhook" : {"0" : val}}}
func normalizeJSONKey(input string) (key string) {
	subKeys := strings.Split(input, ".")
	for i, k := range subKeys {
		if i > 0 {
			key += "."
		}
		if _, err := strconv.Atoi(k); err == nil {
			key += ":" + k
		} else {
			key += k
		}
	}
	return
}

// GetConfigHandler - GET /minio/admin/v1/config-keys
// Get some keys in config.json of this minio setup.
func (a adminAPIHandlers) GetConfigKeysHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "GetConfigKeysHandler")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	var keys []string
	queries := r.URL.Query()

	for k := range queries {
		keys = append(keys, k)
	}

	config, err := readServerConfig(ctx, objectAPI)
	if err != nil {
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	configData, err := json.Marshal(config)
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	configStr := string(configData)
	newConfigStr := `{}`

	for _, key := range keys {
		// sjson.Set does not return an error if key is empty
		// we should check by ourselves here
		if key == "" {
			continue
		}
		val := gjson.Get(configStr, key)
		if j, ierr := sjson.Set(newConfigStr, normalizeJSONKey(key), val.Value()); ierr == nil {
			newConfigStr = j
		}
	}

	password := config.GetCredential().SecretKey
	econfigData, err := madmin.EncryptData(password, []byte(newConfigStr))
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	writeSuccessResponseJSON(w, []byte(econfigData))
}

// toAdminAPIErrCode - converts errXLWriteQuorum error to admin API
// specific error.
func toAdminAPIErrCode(err error) APIErrorCode {
	switch err {
	case errXLWriteQuorum:
		return ErrAdminConfigNoQuorum
	default:
		return toAPIErrorCode(err)
	}
}

// RemoveUser - DELETE /minio/admin/v1/remove-user?accessKey=<access_key>
func (a adminAPIHandlers) RemoveUser(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "RemoveUser")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	// Deny if WORM is enabled
	if globalWORMEnabled {
		writeErrorResponseJSON(w, ErrMethodNotAllowed, r.URL)
		return
	}

	vars := mux.Vars(r)
	accessKey := vars["accessKey"]
	if err := globalIAMSys.DeleteUser(accessKey); err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrInternalError, r.URL)
		return
	}
}

// RemoveUserPolicy - DELETE /minio/admin/v1/remove-user-policy?accessKey=<access_key>
func (a adminAPIHandlers) RemoveUserPolicy(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "RemoveUserPolicy")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	// Deny if WORM is enabled
	if globalWORMEnabled {
		writeErrorResponseJSON(w, ErrMethodNotAllowed, r.URL)
		return
	}

	vars := mux.Vars(r)
	accessKey := vars["accessKey"]
	if err := globalIAMSys.DeletePolicy(accessKey); err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrInternalError, r.URL)
		return
	}
}

// ListUsers - GET /minio/admin/v1/list-users
func (a adminAPIHandlers) ListUsers(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "ListUsers")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	allCredentials, err := globalIAMSys.ListUsers()
	if err != nil {
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	data, err := json.Marshal(allCredentials)
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrInternalError, r.URL)
		return
	}

	password := globalServerConfig.GetCredential().SecretKey
	econfigData, err := madmin.EncryptData(password, data)
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrInternalError, r.URL)
		return
	}

	writeSuccessResponseJSON(w, econfigData)
}

// AddUser - PUT /minio/admin/v1/add-user?accessKey=<access_key>
func (a adminAPIHandlers) AddUser(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "AddUser")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	// Deny if WORM is enabled
	if globalWORMEnabled {
		writeErrorResponseJSON(w, ErrMethodNotAllowed, r.URL)
		return
	}

	vars := mux.Vars(r)
	accessKey := vars["accessKey"]

	// Custom IAM policies not allowed for admin user.
	if accessKey == globalServerConfig.GetCredential().AccessKey {
		writeErrorResponse(w, ErrInvalidRequest, r.URL)
		return
	}

	if r.ContentLength > maxEConfigJSONSize || r.ContentLength == -1 {
		// More than maxConfigSize bytes were available
		writeErrorResponseJSON(w, ErrAdminConfigTooLarge, r.URL)
		return
	}

	password := globalServerConfig.GetCredential().SecretKey
	configBytes, err := madmin.DecryptData(password, io.LimitReader(r.Body, r.ContentLength))
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrAdminConfigBadJSON, r.URL)
		return
	}

	var uinfo madmin.UserInfo
	if err = json.Unmarshal(configBytes, &uinfo); err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrAdminConfigBadJSON, r.URL)
		return
	}

	if err = globalIAMSys.SetUser(accessKey, uinfo); err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrInternalError, r.URL)
		return
	}
}

// AddUserPolicy - PUT /minio/admin/v1/add-user-policy?accessKey=<access_key>
func (a adminAPIHandlers) AddUserPolicy(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "AddUserPolicy")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	vars := mux.Vars(r)
	accessKey := vars["accessKey"]

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	// Deny if WORM is enabled
	if globalWORMEnabled {
		writeErrorResponseJSON(w, ErrMethodNotAllowed, r.URL)
		return
	}

	// Custom IAM policies not allowed for admin user.
	if accessKey == globalServerConfig.GetCredential().AccessKey {
		writeErrorResponse(w, ErrInvalidRequest, r.URL)
		return
	}

	// Error out if Content-Length is missing.
	if r.ContentLength <= 0 {
		writeErrorResponse(w, ErrMissingContentLength, r.URL)
		return
	}

	// Error out if Content-Length is beyond allowed size.
	if r.ContentLength > maxBucketPolicySize {
		writeErrorResponse(w, ErrEntityTooLarge, r.URL)
		return
	}

	iamPolicy, err := iampolicy.ParseConfig(io.LimitReader(r.Body, r.ContentLength))
	if err != nil {
		writeErrorResponse(w, ErrMalformedPolicy, r.URL)
		return
	}

	// Version in policy must not be empty
	if iamPolicy.Version == "" {
		writeErrorResponse(w, ErrMalformedPolicy, r.URL)
		return
	}

	if err = globalIAMSys.SetPolicy(accessKey, *iamPolicy); err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponse(w, ErrInternalError, r.URL)
		return
	}
}

// SetConfigHandler - PUT /minio/admin/v1/config
func (a adminAPIHandlers) SetConfigHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "SetConfigHandler")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	// Deny if WORM is enabled
	if globalWORMEnabled {
		writeErrorResponseJSON(w, ErrMethodNotAllowed, r.URL)
		return
	}

	if r.ContentLength > maxEConfigJSONSize || r.ContentLength == -1 {
		// More than maxConfigSize bytes were available
		writeErrorResponseJSON(w, ErrAdminConfigTooLarge, r.URL)
		return
	}

	password := globalServerConfig.GetCredential().SecretKey
	configBytes, err := madmin.DecryptData(password, io.LimitReader(r.Body, r.ContentLength))
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrAdminConfigBadJSON, r.URL)
		return
	}

	// Validate JSON provided in the request body: check the
	// client has not sent JSON objects with duplicate keys.
	if err = quick.CheckDuplicateKeys(string(configBytes)); err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrAdminConfigBadJSON, r.URL)
		return
	}

	var config serverConfig
	if err = json.Unmarshal(configBytes, &config); err != nil {
		logger.LogIf(ctx, err)
		writeCustomErrorResponseJSON(w, ErrAdminConfigBadJSON, err.Error(), r.URL)
		return
	}

	// If credentials for the server are provided via environment,
	// then credentials in the provided configuration must match.
	if globalIsEnvCreds {
		creds := globalServerConfig.GetCredential()
		if config.Credential.AccessKey != creds.AccessKey ||
			config.Credential.SecretKey != creds.SecretKey {
			writeErrorResponseJSON(w, ErrAdminCredentialsMismatch, r.URL)
			return
		}
	}

	if err = config.Validate(); err != nil {
		writeCustomErrorResponseJSON(w, ErrAdminConfigBadJSON, err.Error(), r.URL)
		return
	}

	if err = saveServerConfig(ctx, objectAPI, &config); err != nil {
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	// Reply to the client before restarting minio server.
	writeSuccessResponseHeadersOnly(w)
}

func convertValueType(elem []byte, jsonType gjson.Type) (interface{}, error) {
	str := string(elem)
	switch jsonType {
	case gjson.False, gjson.True:
		return strconv.ParseBool(str)
	case gjson.JSON:
		return gjson.Parse(str).Value(), nil
	case gjson.String:
		return str, nil
	case gjson.Number:
		return strconv.ParseFloat(str, 64)
	default:
		return nil, nil
	}
}

// SetConfigKeysHandler - PUT /minio/admin/v1/config-keys
func (a adminAPIHandlers) SetConfigKeysHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "SetConfigKeysHandler")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Deny if WORM is enabled
	if globalWORMEnabled {
		writeErrorResponseJSON(w, ErrMethodNotAllowed, r.URL)
		return
	}

	// Validate request signature.
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	// Load config
	configStruct, err := readServerConfig(ctx, objectAPI)
	if err != nil {
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	// Convert config to json bytes
	configBytes, err := json.Marshal(configStruct)
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	configStr := string(configBytes)

	queries := r.URL.Query()
	password := globalServerConfig.GetCredential().SecretKey

	// Set key values in the JSON config
	for k := range queries {
		// Decode encrypted data associated to the current key
		encryptedElem, dErr := base64.StdEncoding.DecodeString(queries.Get(k))
		if dErr != nil {
			reqInfo := (&logger.ReqInfo{}).AppendTags("key", k)
			ctx = logger.SetReqInfo(ctx, reqInfo)
			logger.LogIf(ctx, dErr)
			writeErrorResponseJSON(w, ErrAdminConfigBadJSON, r.URL)
			return
		}
		elem, dErr := madmin.DecryptData(password, bytes.NewBuffer([]byte(encryptedElem)))
		if dErr != nil {
			logger.LogIf(ctx, dErr)
			writeErrorResponseJSON(w, ErrAdminConfigBadJSON, r.URL)
			return
		}
		// Calculate the type of the current key from the
		// original config json
		jsonFieldType := gjson.Get(configStr, k).Type
		// Convert passed value to json filed type
		val, cErr := convertValueType(elem, jsonFieldType)
		if cErr != nil {
			writeCustomErrorResponseJSON(w, ErrAdminConfigBadJSON, cErr.Error(), r.URL)
			return
		}
		// Set the key/value in the new json document
		if s, sErr := sjson.Set(configStr, normalizeJSONKey(k), val); sErr == nil {
			configStr = s
		}
	}

	configBytes = []byte(configStr)

	// Validate config
	var config serverConfig
	if err = json.Unmarshal(configBytes, &config); err != nil {
		writeCustomErrorResponseJSON(w, ErrAdminConfigBadJSON, err.Error(), r.URL)
		return
	}

	if err = config.Validate(); err != nil {
		writeCustomErrorResponseJSON(w, ErrAdminConfigBadJSON, err.Error(), r.URL)
		return
	}

	if err = config.TestNotificationTargets(); err != nil {
		writeCustomErrorResponseJSON(w, ErrAdminConfigBadJSON, err.Error(), r.URL)
		return
	}

	// If credentials for the server are provided via environment,
	// then credentials in the provided configuration must match.
	if globalIsEnvCreds {
		creds := globalServerConfig.GetCredential()
		if config.Credential.AccessKey != creds.AccessKey ||
			config.Credential.SecretKey != creds.SecretKey {
			writeErrorResponseJSON(w, ErrAdminCredentialsMismatch, r.URL)
			return
		}
	}

	if err = saveServerConfig(ctx, objectAPI, &config); err != nil {
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	// Send success response
	writeSuccessResponseHeadersOnly(w)
}

// UpdateAdminCredsHandler - POST /minio/admin/v1/config/credential
// ----------
// Update admin credentials in a minio server
func (a adminAPIHandlers) UpdateAdminCredentialsHandler(w http.ResponseWriter,
	r *http.Request) {

	ctx := newContext(r, w, "UpdateCredentialsHandler")

	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil {
		writeErrorResponseJSON(w, ErrServerNotInitialized, r.URL)
		return
	}

	// Avoid setting new credentials when they are already passed
	// by the environment. Deny if WORM is enabled.
	if globalIsEnvCreds || globalWORMEnabled {
		writeErrorResponseJSON(w, ErrMethodNotAllowed, r.URL)
		return
	}

	// Authenticate request
	adminAPIErr := checkAdminRequestAuthType(r, "")
	if adminAPIErr != ErrNone {
		writeErrorResponseJSON(w, adminAPIErr, r.URL)
		return
	}

	if r.ContentLength > maxEConfigJSONSize || r.ContentLength == -1 {
		// More than maxConfigSize bytes were available
		writeErrorResponseJSON(w, ErrAdminConfigTooLarge, r.URL)
		return
	}

	password := globalServerConfig.GetCredential().SecretKey
	configBytes, err := madmin.DecryptData(password, io.LimitReader(r.Body, r.ContentLength))
	if err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrAdminConfigBadJSON, r.URL)
		return
	}

	// Decode request body
	var req madmin.SetCredsReq
	if err = json.Unmarshal(configBytes, &req); err != nil {
		logger.LogIf(ctx, err)
		writeErrorResponseJSON(w, ErrRequestBodyParse, r.URL)
		return
	}

	creds, err := auth.CreateCredentials(req.AccessKey, req.SecretKey)
	if err != nil {
		writeErrorResponseJSON(w, toAPIErrorCode(err), r.URL)
		return
	}

	// Acquire lock before updating global configuration.
	globalServerConfigMu.Lock()
	defer globalServerConfigMu.Unlock()

	// Update local credentials in memory.
	globalServerConfig.SetCredential(creds)

	// Set active creds.
	globalActiveCred = creds

	if err = saveServerConfig(ctx, objectAPI, globalServerConfig); err != nil {
		writeErrorResponseJSON(w, toAdminAPIErrCode(err), r.URL)
		return
	}

	// Notify all other Minio peers to update credentials
	for host, err := range globalNotificationSys.LoadCredentials() {
		if err != nil {
			logger.GetReqInfo(ctx).SetTags("peerAddress", host.String())
			logger.LogIf(ctx, err)
		}
	}

	// Reply to the client before restarting minio server.
	writeSuccessResponseHeadersOnly(w)
}