fix(gateway): question marks in url.Path when redirecting (#313)

Co-authored-by: Marcin Rataj <[email protected]>

gateway/hostname.go

@@ -328,24 +328,10 @@ func toDNSLinkFQDN(dnsLabel string) (fqdn string) {
 
 // Converts a hostname/path to a subdomain-based URL, if applicable.
 func toSubdomainURL(hostname, path string, r *http.Request, inlineDNSLink bool, api IPFSBackend) (redirURL string, err error) {
-	var scheme, ns, rootID, rest string
+	var ns, rootID, rest string
 
-	query := r.URL.RawQuery
 	parts := strings.SplitN(path, "/", 4)
 	isHTTPS := isHTTPSRequest(r)
-	safeRedirectURL := func(in string) (out string, err error) {
-		safeURI, err := url.ParseRequestURI(in)
-		if err != nil {
-			return "", err
-		}
-		return safeURI.String(), nil
-	}
-
-	if isHTTPS {
-		scheme = "https:"
-	} else {
-		scheme = "http:"
-	}
 
 	switch len(parts) {
 	case 4:
@@ -362,11 +348,6 @@ func toSubdomainURL(hostname, path string, r *http.Request, inlineDNSLink bool,
 		return "", nil
 	}
 
-	// add prefix if query is present
-	if query != "" {
-		query = "?" + query
-	}
-
 	// Normalize problematic PeerIDs (eg. ed25519+identity) to CID representation
 	if isPeerIDNamespace(ns) && !isDomainNameAndNotPeerID(rootID) {
 		peerID, err := peer.Decode(rootID)
@@ -452,15 +433,21 @@ func toSubdomainURL(hostname, path string, r *http.Request, inlineDNSLink bool,
 		return "", nil
 	}
 
-	return safeRedirectURL(fmt.Sprintf(
-		"%s//%s.%s.%s/%s%s",
-		scheme,
-		rootID,
-		ns,
-		hostname,
-		rest,
-		query,
-	))
+	// Produce subdomain redirect URL in a way that preserves any
+	// percent-encoded paths and query parameters
+	u, err := url.Parse(fmt.Sprintf("http://%s.%s.%s/", rootID, ns, hostname))
+	if err != nil {
+		return "", err
+	}
+	u.RawFragment = r.URL.RawFragment
+	u.RawQuery = r.URL.RawQuery
+	if rest != "" {
+		u.Path = rest
+	}
+	if isHTTPS {
+		u.Scheme = "https"
+	}
+	return u.String(), nil
 }
 
 func hasPrefix(path string, prefixes ...string) bool {

gateway/hostname_test.go

@@ -34,7 +34,6 @@ func TestToSubdomainURL(t *testing.T) {
 		url string
 		err error
 	}{
-
 		// DNSLink
 		{httpRequest, "localhost", false, "/ipns/dnslink.io", "http://dnslink.io.ipns.localhost/", nil},
 		// Hostname with port
@@ -56,6 +55,9 @@ func TestToSubdomainURL(t *testing.T) {
 		// HTTP requests can also be converted to fit into a single DNS label - https://github.com/ipfs/kubo/issues/9243
 		{httpRequest, "localhost", true, "/ipns/dnslink.long-name.example.com", "http://dnslink-long--name-example-com.ipns.localhost/", nil},
 		{httpRequest, "dweb.link", true, "/ipns/dnslink.long-name.example.com", "http://dnslink-long--name-example-com.ipns.dweb.link/", nil},
+		// Correctly redirects paths when there is a ? (question mark) character - https://github.com/ipfs/kubo/issues/9882
+		{httpRequest, "localhost", false, "/ipns/example.com/this is a file with some spaces . dots and - but also a ?.png", "http://example.com.ipns.localhost/this%20is%20a%20file%20with%20some%20spaces%20.%20dots%20and%20-%20but%20also%20a%20%3F.png", nil},
+		{httpRequest, "localhost", false, "/ipfs/QmbCMUZw6JFeZ7Wp9jkzbye3Fzp2GGcPgC3nmeUjfVF87n/this is a file with some spaces . dots and - but also a ?.png", "http://bafybeif7a7gdklt6hodwdrmwmxnhksctcuav6lfxlcyfz4khzl3qfmvcgu.ipfs.localhost/this%20is%20a%20file%20with%20some%20spaces%20.%20dots%20and%20-%20but%20also%20a%20%3F.png", nil},
 	} {
 		testName := fmt.Sprintf("%s, %v, %s", test.gwHostname, test.inlineDNSLink, test.path)
 		t.Run(testName, func(t *testing.T) {