Function parseKeyString

internal/database/ssh_key.go:107–174

parseKeyString parses any key string in OpenSSH or SSH2 format to clean OpenSSH string (RFC4253).

(content string)

// parseKeyString parses any key string in OpenSSH or SSH2 format to clean OpenSSH string (RFC4253).
func parseKeyString(content string) (string, error) {
	// Transform all legal line endings to a single "\n"

	// Replace all windows full new lines ("\r\n")
	content = strings.ReplaceAll(content, "\r\n", "\n")

	// Replace all windows half new lines ("\r"), if it happen not to match replace above
	content = strings.ReplaceAll(content, "\r", "\n")

	// Replace ending new line as its may cause unwanted behaviour (extra line means not a single line key | OpenSSH key)
	content = strings.TrimRight(content, "\n")

	// split lines
	lines := strings.Split(content, "\n")

	var keyType, keyContent, keyComment string

	if len(lines) == 1 {
		// Parse OpenSSH format.
		parts := strings.SplitN(lines[0], " ", 3)
		switch len(parts) {
		case 0:
			return "", errors.New("empty key")
		case 1:
			keyContent = parts[0]
		case 2:
			keyType = parts[0]
			keyContent = parts[1]
		default:
			keyType = parts[0]
			keyContent = parts[1]
			keyComment = parts[2]
		}

		// If keyType is not given, extract it from content. If given, validate it.
		t, err := extractTypeFromBase64Key(keyContent)
		if err != nil {
			return "", errors.Newf("extractTypeFromBase64Key: %v", err)
		}
		if keyType == "" {
			keyType = t
		} else if keyType != t {
			return "", errors.Newf("key type and content does not match: %s - %s", keyType, t)
		}
	} else {
		// Parse SSH2 file format.
		continuationLine := false

		for _, line := range lines {
			// Skip lines that:
			// 1) are a continuation of the previous line,
			// 2) contain ":" as that are comment lines
			// 3) contain "-" as that are begin and end tags
			if continuationLine || strings.ContainsAny(line, ":-") {
				continuationLine = strings.HasSuffix(line, "\\")
			} else {
				keyContent = keyContent + line
			}