// to make parsing easier.
	v4Auth = strings.ReplaceAll(v4Auth, " ", "")
	if v4Auth == "" {
		return sv, ErrAuthHeaderEmpty
	}

	// Verify if the header algorithm is supported or not.
	if !strings.HasPrefix(v4Auth, signV4Algorithm) {
		return sv, ErrSignatureVersionNotSupported
	}

	// Strip off the Algorithm prefix.
	v4Auth = strings.TrimPrefix(v4Auth, signV4Algorithm)

		json := jsoniter.ConfigCompatibleWithStandardLibrary
		if err := json.Unmarshal(b, &ctx); err != nil {
			return "", nil, err
		}
	}

	keyID := h.Get(xhttp.AmzServerSideEncryptionKmsID)
	spaces := strings.HasPrefix(keyID, " ") || strings.HasSuffix(keyID, " ")
	if spaces {
		return "", nil, ErrInvalidEncryptionKeyID
	}
	return strings.TrimPrefix(keyID, ARNPrefix), ctx, nil
}

// directories that MkdirAll creates.
// If path is already a directory, MkdirAll does nothing
// and returns nil.
func osMkdirAll(dirPath string, perm os.FileMode, baseDir string) error {
	if baseDir != "" {
		if strings.HasPrefix(baseDir, dirPath) {
			return nil
		}
	}

	// Slow path: make sure parent exists and then call Mkdir for path.
	i := len(dirPath)
	for i > 0 && os.IsPathSeparator(dirPath[i-1]) { // Skip trailing path separator.

		refName        = rel.Name + "."
		values         = rValues.Interface()
	)

	for name, ok := range selectColumns {
		columnName := ""
		if strings.HasPrefix(name, refName) {
			columnName = strings.TrimPrefix(name, refName)
		}

		if columnName != "" {
			if ok {
				selects = append(selects, columnName)
			} else {
				omits = append(omits, columnName)

}

// Validate validates input key rotation encryption options.
func (e BatchJobKeyRotateEncryption) Validate() error {
	if e.Type != sses3 && e.Type != ssekms {
		return errInvalidArgument
	}
	spaces := strings.HasPrefix(e.Key, " ") || strings.HasSuffix(e.Key, " ")
	if e.Type == ssekms && spaces {
		return crypto.ErrInvalidEncryptionKeyID
	}
	if e.Type == ssekms && GlobalKMS != nil {
		ctx := kms.Context{}
		if e.Context != "" {

			d.ReplicationStatusInternal = v
			d.Targets = replicationStatusesMap(v)
		case equals(k, VersionPurgeStatusKey):
			d.VersionPurgeStatusInternal = v
			d.PurgeTargets = versionPurgeStatusesMap(v)
		case strings.HasPrefix(k, ReservedMetadataPrefixLower+ReplicationReset):
			arn := strings.TrimPrefix(k, fmt.Sprintf("%s-", ReservedMetadataPrefixLower+ReplicationReset))
			if d.ResetStatusesMap == nil {

		// Skip forward, if requested...
		sb := bytebufferpool.Get()
		defer func() {
			sb.Reset()
			bytebufferpool.Put(sb)
		}()

		forward := ""
		if len(opts.ForwardTo) > 0 && strings.HasPrefix(opts.ForwardTo, current) {
			forward = strings.TrimPrefix(opts.ForwardTo, current)
			// Trim further directories and trailing slash.
			if idx := strings.IndexByte(forward, '/'); idx > 0 {
				forward = forward[:idx]

	checkHeader := map[string][]string{}
	ignoreKeys := map[string]bool{}
	for key, value := range formValues {
		switch {
		case ignoreKeys[key], postPolicyIgnoreKeys[key], strings.HasPrefix(key, encrypt.SseGenericHeader):
			continue
		case strings.HasPrefix(key, "X-Amz-Ignore-"):
			ignoreKey := strings.Replace(key, "X-Amz-Ignore-", "", 1)
			ignoreKeys[ignoreKey] = true
			// if it have already
			delete(checkHeader, ignoreKey)

func parsEnvEntry(envEntry string) (envKV, error) {
	envEntry = strings.TrimSpace(envEntry)
	if envEntry == "" {
		// Skip all empty lines
		return envKV{
			Skip: true,
		}, nil
	}
	if strings.HasPrefix(envEntry, "#") {
		// Skip commented lines
		return envKV{
			Skip: true,
		}, nil
	}
	envTokens := strings.SplitN(strings.TrimSpace(strings.TrimPrefix(envEntry, "export")), config.EnvSeparator, 2)

func (c Config) DelFrom(r io.Reader) error {
	scanner := bufio.NewScanner(r)
	for scanner.Scan() {
		// Skip any empty lines, or comment like characters
		text := scanner.Text()
		if text == "" || strings.HasPrefix(text, KvComment) {
			continue
		}
		if err := c.DelKVS(text); err != nil {
			return err
		}
	}
	return scanner.Err()
}

// ContextKeyString is type(string) for contextKey