fiber/middleware/cors/utils.go
Juan Calderon-Perez da726507c5
fix linter
2025-08-19 09:40:04 -04:00

94 lines
2.8 KiB
Go

package cors
import (
"net/url"
"strings"
)
// matchScheme compares the scheme of the domain and pattern
func matchScheme(domain, pattern string) bool {
didx := strings.Index(domain, ":")
pidx := strings.Index(pattern, ":")
return didx != -1 && pidx != -1 && domain[:didx] == pattern[:pidx]
}
// normalizeDomain removes the scheme and port from the input domain
func normalizeDomain(input string) string {
// Remove scheme
input = strings.TrimPrefix(strings.TrimPrefix(input, "http://"), "https://")
// Find and remove port, if present
if len(input) > 0 && input[0] != '[' {
if portIndex := strings.Index(input, ":"); portIndex != -1 {
input = input[:portIndex]
}
}
return input
}
// normalizeOrigin checks if the provided origin is in a correct format
// and normalizes it by removing any path or trailing slash.
// It returns a boolean indicating whether the origin is valid
// and the normalized origin.
func normalizeOrigin(origin string) (bool, string) {
parsedOrigin, err := url.Parse(origin)
if err != nil {
return false, ""
}
// Don't allow a wildcard with a protocol
// wildcards cannot be used within any other value. For example, the following header is not valid:
// Access-Control-Allow-Origin: https://*
if strings.Contains(parsedOrigin.Host, "*") {
return false, ""
}
// Validate there is a host present. The presence of a path, query, or fragment components
// is checked, but a trailing "/" (indicative of the root) is allowed for the path and will be normalized
if parsedOrigin.Host == "" || (parsedOrigin.Path != "" && parsedOrigin.Path != "/") || parsedOrigin.RawQuery != "" || parsedOrigin.Fragment != "" {
return false, ""
}
// Normalize the origin by constructing it from the scheme and host.
// The path or trailing slash is not included in the normalized origin.
return true, strings.ToLower(parsedOrigin.Scheme + "://" + parsedOrigin.Host)
}
type subdomain struct {
// The wildcard pattern
prefix string
suffix string
}
func (s subdomain) match(o string) bool {
// Not a subdomain if not long enough for a dot separator.
if len(o) < len(s.prefix)+len(s.suffix)+1 {
return false
}
if !strings.HasPrefix(o, s.prefix) || !strings.HasSuffix(o, s.suffix) {
return false
}
// Check for the dot separator and validate that there is at least one
// non-empty label between prefix and suffix. Empty labels like
// "https://.example.com" or "https://..example.com" should not match.
suffixStartIndex := len(o) - len(s.suffix)
if suffixStartIndex <= len(s.prefix) {
return false
}
if o[suffixStartIndex-1] != '.' {
return false
}
// Extract the subdomain part (without the trailing dot) and ensure it
// doesn't contain empty labels.
sub := o[len(s.prefix) : suffixStartIndex-1]
if sub == "" || strings.HasPrefix(sub, ".") || strings.Contains(sub, "..") {
return false
}
return true
}