return subtle.ConstantTimeCompare([]byte(sig1), []byte(sig2)) == 1
}

// doesPolicySignatureMatch - Verify query headers with post policy
//   - http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-HTTPPOSTConstructPolicy.html
//
// returns ErrNone if the signature matches.
func doesPolicySignatureV4Match(formValues http.Header) (auth.Credentials, APIErrorCode) {
	// Server region.
	region := globalSite.Region

	}
	return secret, nil
}

// AssumeRole - implementation of AWS STS API AssumeRole to get temporary
// credentials for regular users on Minio.
// https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html
func (sts *stsAPIHandlers) AssumeRole(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "AssumeRole")

	claims := make(map[string]interface{})
	defer logger.AuditLog(ctx, w, r, claims)

	}

	*dr = DefaultRetention(retention)

	return nil
}

// Config - object lock configuration specified in
// https://docs.aws.amazon.com/AmazonS3/latest/API/Type_API_ObjectLockConfiguration.html
type Config struct {
	XMLNS             string   `xml:"xmlns,attr,omitempty"`
	XMLName           xml.Name `xml:"ObjectLockConfiguration"`
	ObjectLockEnabled string   `xml:"ObjectLockEnabled"`
	Rule              *struct {

	// Maximum size for http headers - See: https://docs.aws.amazon.com/AmazonS3/latest/dev/UsingMetadata.html
	maxHeaderSize = 8 * 1024

	// Maximum size for user-defined metadata - See: https://docs.aws.amazon.com/AmazonS3/latest/dev/UsingMetadata.html
	maxUserDataSize = 2 * 1024

	// maxBuckets upto 500000 for any MinIO deployment.
	maxBuckets = 500 * 1000
)

//
// arn:partition:service:region:account-id:resource-type/resource-id
//
// In this implementation, account-id is empty.
//
// Reference: https://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html

const (
	arnPrefixArn        = "arn"
	arnPartitionMinio   = "minio"
	arnServiceIAM       = "iam"
	arnResourceTypeRole = "role"
)

// ARN - representation of resources based on AWS ARNs.
type ARN struct {

	bucketSSEConfig = "bucket-encryption.xml"
)

// PutBucketEncryptionHandler - Stores given bucket encryption configuration
// https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutBucketEncryption.html
func (api objectAPIHandlers) PutBucketEncryptionHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "PutBucketEncryption")

	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))

		if getRequestAuthType(r) == authTypeAnonymous {
			// As per "Permission" section in
			// https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectGET.html
			// If the object you request does not exist,
			// the error Amazon S3 returns depends on
			// whether you also have the s3:ListBucket
			// permission.
			// * If you have the s3:ListBucket permission

					return ObjectLocked{}
				}

				if !ret.RetainUntilDate.Before(t) {
					return ObjectLocked{}
				}
				return nil
			}
			// https://docs.aws.amazon.com/AmazonS3/latest/dev/object-lock-overview.html#object-lock-retention-modes
			// If you try to delete objects protected by governance mode and have s3:BypassGovernanceRetention, the operation will succeed.

type STSErrorCode int

//go:generate stringer -type=STSErrorCode -trimprefix=Err $GOFILE

// Error codes, non exhaustive list - http://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRoleWithSAML.html
const (
	ErrSTSNone STSErrorCode = iota
	ErrSTSAccessDenied
	ErrSTSMissingParameter
	ErrSTSInvalidParameterValue
	ErrSTSWebIdentityExpiredToken
	ErrSTSClientGrantsExpiredToken
	ErrSTSInvalidClientGrantsToken

		sessionName := conf.AWSRoleSessionName
		if sessionName == "" {
			// RoleSessionName has a limited set of characters (https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html)
			sessionName = "minio-tier-" + mustGetUUID()
		}
		s3WebIdentityIAM := credentials.IAM{
			Client: &http.Client{
				Transport: NewHTTPTransport(),
			},
			EKSIdentity: struct {