Files
narratio/internal/pathsafe/opaque_segment.go

35 lines
1.1 KiB
Go

package pathsafe
import (
"errors"
"fmt"
)
var (
ErrOpaqueSegmentRequired = errors.New("opaque identifier is required")
ErrOpaqueSegmentInvalid = errors.New("opaque identifier must contain only ASCII letters, digits, '.', '_', or '-'")
)
// ValidateOpaqueSegment validates an identity token that occupies exactly one
// portable local-path and object-key segment. It deliberately does not trim or
// normalize input: callers must reject rather than silently rewrite identity.
func ValidateOpaqueSegment(value string) error {
if value == "" {
return ErrOpaqueSegmentRequired
}
if value == "." || value == ".." {
return fmt.Errorf("%w: dot segments are not allowed", ErrOpaqueSegmentInvalid)
}
for index := 0; index < len(value); index++ {
character := value[index]
if (character >= 'a' && character <= 'z') ||
(character >= 'A' && character <= 'Z') ||
(character >= '0' && character <= '9') ||
character == '.' || character == '_' || character == '-' {
continue
}
return fmt.Errorf("%w: invalid byte at offset %d", ErrOpaqueSegmentInvalid, index)
}
return nil
}