if r == nil {
		return nil
	}
	r.Lock()
	defer r.Unlock()
	r.tags = append(r.tags, KeyVal{key, val})
	return r
}

// SetTags - sets key/val to ReqInfo.tags
func (r *ReqInfo) SetTags(key string, val interface{}) *ReqInfo {
	if r == nil {
		return nil
	}
	r.Lock()
	defer r.Unlock()
	// Search of tag key already exists in tags
	var updated bool

	mac := hmac.New(sha256.New, key[:])
	mac.Write(bin[:])
	mac.Sum(partKey[:0])
	return partKey
}

// SealETag seals the etag using the object key.
// It does not encrypt empty ETags because such ETags indicate
// that the S3 client hasn't sent an ETag = MD5(object) and
// the backend can pick an ETag value.
func (key ObjectKey) SealETag(etag []byte) []byte {

// objects are slightly larger due to encryption overhead.
// Further, it decrypts all single-part SSE-S3 encrypted objects
// and formats ETags of SSE-C / SSE-KMS encrypted objects to
// be AWS S3 compliant.
//
// DecryptETags uses a KMS bulk decryption API, if available, which
// is more efficient than decrypting ETags sequentually.
func DecryptETags(ctx context.Context, k kms.KMS, objects []ObjectInfo) error {

		return nil
	}

	// Notify all other MinIO peers to delete policy
	for _, nerr := range globalNotificationSys.DeletePolicy(policyName) {
		if nerr.Err != nil {
			logger.GetReqInfo(ctx).SetTags("peerAddress", nerr.Host.String())
			iamLogIf(ctx, nerr.Err)
		}
	}

	return nil
}

// InfoPolicy - returns the policy definition with some metadata.

	//   ETag := MD5(ETag_p1, ETag_p2, ...)+"-N"   (N being the number of parts)
	//
	// This is independent of encryption. An encrypted multipart
	// object also has an ETag that is the MD5 of its part ETags.
	// The fact the in case of encryption the ETag of a part is
	// not the MD5 of the part content does not change that.
	var completeETags []etag.ETag
	for _, part := range complMultipartUpload.Parts {

		ObjectInfo: ObjectInfo{ETag: "00000f00f27834c9a2654927546df57f9e998187496394d4ee80f3d9978f85f3c7d81f72600cdbe03d80dc5a13d69354"},
		ETag:       "",
		ShouldFail: true, // modified ETag
	},

	// Special tests for ETags that end with a '-x'
	{
		ObjectKey:  [32]byte{},
		ObjectInfo: ObjectInfo{ETag: "916516b396f0f4d4f2a0e7177557bec4-1"},
		ETag:       "916516b396f0f4d4f2a0e7177557bec4-1",
	},
	{
		ObjectKey:  [32]byte{},

package cmd

import (
	"bytes"
	"context"
	"time"

	"github.com/minio/madmin-go/v3"
)

func commonETags(etags []string) (etag string, maxima int) {
	etagOccurrenceMap := make(map[string]int, len(etags))

	// Ignore the uuid sentinel and count the rest.
	for _, etag := range etags {
		if etag == "" {
			continue
		}
		etagOccurrenceMap[etag]++
	}

// S3 singlepart ETags. It returns nil if the list of
// ETags is empty.
//
// Any encrypted or multipart ETag will be ignored and not
// used to compute the returned ETag.
func Multipart(etags ...ETag) ETag {
	if len(etags) == 0 {
		return nil
	}

	var n int64
	h := md5.New()
	for _, etag := range etags {
		if !etag.IsMultipart() && !etag.IsEncrypted() {

	}
}

var multipartTests = []struct { // Test cases have been generated using AWS S3
	ETags     []ETag
	Multipart ETag
}{
	{
		ETags:     []ETag{},
		Multipart: ETag{},
	},
	{
		ETags:     []ETag{must("b10a8db164e0754105b7a99be72e3fe5")},
		Multipart: must("7b976cc68452e003eec7cb0eb631a19a-1"),
	},
	{
		ETags:     []ETag{must("5f363e0e58a95f06cbe9bbc662c5dfb6"), must("5f363e0e58a95f06cbe9bbc662c5dfb6")},

// A Reader wraps an io.Reader and computes the
// MD5 checksum of the read content as ETag.
//
// Optionally, a Reader can also verify that
// the computed ETag matches an expected value.
// Therefore, it compares both ETags once the
// underlying io.Reader returns io.EOF.
// If the computed ETag does not match the
// expected ETag then Read returns a VerifyError.
//
// Reader implements the Tagger interface.
type Reader struct {