type Retention struct {
	Mode        RetMode
	Validity    time.Duration
	LockEnabled bool
}

// Retain - check whether given date is retainable by validity time.
func (r Retention) Retain(created time.Time) bool {
	t, err := UTCNowNTP()
	if err != nil {
		lockLogIf(context.Background(), err)
		// Retain
		return true
	}
	return created.Add(r.Validity).After(t)
}

- `outputToken` – A token added to the response headers when the Lambda function returns the transformed object. This is used by MinIO to verify the incoming response validity.

Lets start the lambda handler.

```
python lambda_handler.py
 * Serving Flask app 'webhook'
 * Debug mode: off

```
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            35:ac:60:46:ad:8d:de:18:dc:0b:f6:98:14:ee:89:e8
        Signature Algorithm: ED25519
        Issuer: CN = consoleAdmin
        Validity
            Not Before: Jul 19 15:08:44 2021 GMT
            Not After : Aug 18 15:08:44 2021 GMT
        Subject: CN = consoleAdmin
        Subject Public Key Info:
            Public Key Algorithm: ED25519

		return rMode, rDate, legalHold, ErrNone
	}
	if replica { // replica inherits retention metadata only from source
		return "", objectlock.RetentionDate{}, legalHold, ErrNone
	}
	if !retentionRequested && retentionCfg.Validity > 0 {
		if retentionPermErr != ErrNone {
			return mode, retainDate, legalHold, retentionPermErr
		}

		t, err := objectlock.UTCNowNTP()
		if err != nil {
			internalLogIf(ctx, err, logger.WarningKind)

					ARN:    "arn:minio:replication:::dest-bucket",
					Bucket: "dest-bucket",
				},
			},
		},
	}
	lr := objectlock.Retention{
		Mode:        objectlock.RetCompliance,
		Validity:    12 * time.Hour,
		LockEnabled: true,
	}

	expiryWorker := func(wg *sync.WaitGroup, readyCh chan<- struct{}, taskCh <-chan expiryOp, gotExpired *[]ObjectToDelete) {
		defer wg.Done()

By default, the temporary security credentials created by AssumeRoleWithWebIdentity last for one hour. However, the optional DurationSeconds parameter can be used to specify the validity duration of the generated credentials. This value varies from 900 seconds (15 minutes) up to the maximum session duration of 365 days.

## Configuring OpenID Identity Provider on MinIO

	URL         *xnet.URL
	AuthToken   string
	Transport   http.RoundTripper
	CloseRespFn func(r io.ReadCloser)

	RolePolicy string
	RoleARN    arn.ARN
}

// Validate - validate configuration params.
func (a *Args) Validate() error {
	req, err := http.NewRequest(http.MethodPost, a.URL.String(), bytes.NewReader([]byte("")))
	if err != nil {
		return err
	}

You can try it already in the interactive docs:

<img src="/img/tutorial/security/image03.png">

We are not verifying the validity of the token yet, but that's a start already.

## Recap { #recap }

	// Shuffle slice xl metadata for expected distribution.
	for index := range partsMetadata {
		if disks[index] == nil {
			continue
		}
		if !init && !partsMetadata[index].IsValid() {
			// Check for parts metadata validity for only
			// fi.ModTime is not empty - ModTime is always set,
			// if object was ever written previously.
			continue
		}
		if !init && fi.XLV1 != partsMetadata[index].XLV1 {
			continue
		}

	}
	// Request more data.
	return 0, nil, nil
}

// isSpace reports whether the character is a Unicode white space character.
// We avoid dependency on the unicode package, but check validity of the implementation
// in the tests.
func isSpace(r rune) bool {
	if r <= '\u00FF' {
		// Obvious ASCII ones: \t through \r plus space. Plus two Latin-1 oddballs.
		switch r {