s string
		t time.Time
	}{
		{"2010T", time.Date(2010, 1, 1, 0, 0, 0, 0, time.UTC)},
		{"2010-02T", time.Date(2010, 2, 1, 0, 0, 0, 0, time.UTC)},
		{"2010-02-03T", time.Date(2010, 2, 3, 0, 0, 0, 0, time.UTC)},
		{"2010-02-03T04:11Z", time.Date(2010, 2, 3, 4, 11, 0, 0, time.UTC)},
		{"2010-02-03T04:11:30Z", time.Date(2010, 2, 3, 4, 11, 30, 0, time.UTC)},
		{"2010-02-03T04:11:30.23Z", time.Date(2010, 2, 3, 4, 11, 30, 230000000, time.UTC)},

	return signedHeaders, ErrNone
}

// signValues data type represents structured form of AWS Signature V4 header.
type signValues struct {
	Credential    credentialHeader
	SignedHeaders []string
	Signature     string
}

// preSignValues data type represents structured form of AWS Signature V4 query string.
type preSignValues struct {
	signValues
	Date    time.Time
	Expires time.Duration
}

	// Add the algorithm condition, only accept AWS SignV4 Sha256.
	algorithmConditionStr := `["eq", "$x-amz-algorithm", "AWS4-HMAC-SHA256"]`
	// Add the date condition, only accept the current date.
	dateConditionStr := fmt.Sprintf(`["eq", "$x-amz-date", "%s"]`, t.Format(iso8601DateFormat))
	// Add the credential string, only accept the credential passed.

		canonicalHeaders += "\n"
	}

	date := expires // Date is set to expires date for presign operations.
	if date == "" {
		// If expires date is empty then request header Date is used.
		date = headers.Get(xhttp.Date)
	}

	// From the Amazon docs:
	//
	// StringToSign = HTTP-Verb + "\n" +
	// 	 Content-Md5 + "\n" +
	//	 Content-Type + "\n" +
	//	 Date/Expires + "\n" +
	//	 CanonicalizedProtocolHeaders +

			success: false,
		},
		// no duplicates, shall be parsed properly.
		{

Accept-Ranges: bytes
Content-Length: 0
Server: MinIO
Vary: Origin
X-Amz-Bucket-Region: us-east-1
X-Minio-Write-Quorum: 3
X-Amz-Request-Id: 16239D6AB80EBECF
X-Xss-Protection: 1; mode=block
Date: Tue, 21 Jul 2020 00:36:14 GMT
```

### Cluster-readable probe

The reply is '200 OK' if cluster has read quorum if not it returns '503 Service Unavailable'.

```
curl http://minio1:9001/minio/health/cluster/read

	region = signV4Values.Credential.scope.region

	// Extract date, if not present throw error.
	var dateStr string
	if dateStr = req.Header.Get("x-amz-date"); dateStr == "" {
		if dateStr = r.Header.Get("Date"); dateStr == "" {
			return cred, "", "", time.Time{}, ErrMissingDateHeader
		}
	}

	// Parse date header.
	var err error
	date, err = time.Parse(iso8601Format, dateStr)
	if err != nil {

		}
		rMode, rDate, err := objectlock.ParseObjectLockRetentionHeaders(rq.Header)
		if err != nil && !(replica && rMode == "" && rDate.IsZero()) {
			return mode, retainDate, legalHold, toAPIErrorCode(ctx, err)
		}
		if retentionPermErr != ErrNone {
			return mode, retainDate, legalHold, retentionPermErr
		}
		return rMode, rDate, legalHold, ErrNone
	}

```sh
aws s3api put-object --bucket testbucket --key lockme --object-lock-mode GOVERNANCE --object-lock-retain-until-date "2019-11-20"  --body /etc/issue
```

Author: Klaus Post <******@****.***>
Date:   Thu Nov 18 12:15:22 2021 -0800

    Improve performance on multiple versions (#13573)
```

- A fix must be a valid fix that was reproduced and seen in a customer environment, for example.

```
commit 886262e58af77ebc7c836ef587c08544e9a0c271
Author: Harshavardhana <******@****.***>
Date:   Wed Nov 17 15:49:12 2021 -0800