wip: migrate to mono-repo. SPN has already been moved to spn/

spn/hub/format.go

@@ -0,0 +1,69 @@
+package hub
+
+import (
+	"fmt"
+	"net"
+	"regexp"
+
+	"github.com/safing/portmaster/service/network/netutils"
+)
+
+// BaselineCharset defines the permitted characters.
+var BaselineCharset = regexp.MustCompile(
+	// Start of charset selection.
+	`^[` +
+		// Printable ASCII (character code 32-127), excluding common control characters of different languages: "$%&';<>\` and DELETE.
+		` !#()*+,\-\./0-9:=?@A-Z[\]^_a-z{|}~` +
+		// Only latin characters from extended ASCII (character code 128-255).
+		`ŠŒŽšœžŸ¡¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿ` +
+		// End of charset selection.
+		`]*$`,
+)
+
+func checkStringFormat(fieldName, value string, maxLength int) error {
+	switch {
+	case len(value) > maxLength:
+		return fmt.Errorf("field %s with length of %d exceeds max length of %d", fieldName, len(value), maxLength)
+	case !BaselineCharset.MatchString(value):
+		return fmt.Errorf("field %s contains characters not permitted by baseline validation", fieldName)
+	default:
+		return nil
+	}
+}
+
+func checkStringSliceFormat(fieldName string, value []string, maxLength, maxStringLength int) error { //nolint:unparam
+	if len(value) > maxLength {
+		return fmt.Errorf("field %s with array/slice length of %d exceeds max length of %d", fieldName, len(value), maxLength)
+	}
+	for _, s := range value {
+		if err := checkStringFormat(fieldName, s, maxStringLength); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func checkByteSliceFormat(fieldName string, value []byte, maxLength int) error {
+	switch {
+	case len(value) > maxLength:
+		return fmt.Errorf("field %s with length of %d exceeds max length of %d", fieldName, len(value), maxLength)
+	default:
+		return nil
+	}
+}
+
+func checkIPFormat(fieldName string, value net.IP) error {
+	// Check if there is an IP address.
+	if value == nil {
+		return nil
+	}
+
+	switch {
+	case len(value) != 4 && len(value) != 16:
+		return fmt.Errorf("field %s has an invalid length of %d for an IP address", fieldName, len(value))
+	case netutils.GetIPScope(value) == netutils.Invalid:
+		return fmt.Errorf("field %s holds an invalid IP address: %s", fieldName, value)
+	default:
+		return nil
+	}
+}