s3api: preserve Host header port in signature verification (#8434)

Avoid stripping default ports (80/443) from the Host header in extractHostHeader.
This fixes SignatureDoesNotMatch errors when SeaweedFS is accessed via a proxy
(like Kong Ingress) that explicitly includes the port in the Host header or
X-Forwarded-Host, which S3 clients sign.

Also cleaned up unused variables and logic after refactoring.

weed/s3api/auth_signature_v4.go

@@ -788,25 +788,9 @@ func extractSignedHeaders(signedHeaders []string, r *http.Request) (http.Header,
 func extractHostHeader(r *http.Request) string {
 	forwardedHost := r.Header.Get("X-Forwarded-Host")
 	forwardedPort := r.Header.Get("X-Forwarded-Port")
-	forwardedProto := r.Header.Get("X-Forwarded-Proto")
-
-	// Determine the effective scheme with correct order of precedence:
-	// 1. X-Forwarded-Proto (most authoritative, reflects client's original protocol)
-	// 2. r.TLS (authoritative for direct connection to server)
-	// 3. r.URL.Scheme (fallback, may not always be set correctly)
-	// 4. Default to "http"
-	scheme := "http"
-	if r.URL.Scheme != "" {
-		scheme = r.URL.Scheme
-	}
-	if r.TLS != nil {
-		scheme = "https"
-	}
-	if forwardedProto != "" {
-		scheme = forwardedProto
-	}
 
 	var host, port string
+	explicitPort := false
 	if forwardedHost != "" {
 		// X-Forwarded-Host can be a comma-separated list of hosts when there are multiple proxies.
 		// Use only the first host in the list and trim spaces for robustness.
@@ -815,12 +799,16 @@ func extractHostHeader(r *http.Request) string {
 		} else {
 			host = strings.TrimSpace(forwardedHost)
 		}
+		// Baseline port from forwarded port if available
+		if forwardedPort != "" {
+			port = forwardedPort
+			explicitPort = true
+		}
+		// If the host itself contains a port, it should take precedence
 		if h, p, err := net.SplitHostPort(host); err == nil {
 			host = h
 			port = p
-		}
+			explicitPort = true
-		if forwardedPort != "" && isDefaultPort(scheme, port) {
-			port = forwardedPort
 		}
 	} else {
 		host = r.Host
@@ -830,12 +818,13 @@ func extractHostHeader(r *http.Request) string {
 		if h, p, err := net.SplitHostPort(host); err == nil {
 			host = h
 			port = p
+			explicitPort = true
 		}
 	}
 
-	// If we have a non-default port, join it with the host.
+	// If a port was explicitly provided, join it with the host.
 	// net.JoinHostPort will handle bracketing for IPv6.
-	if port != "" && !isDefaultPort(scheme, port) {
+	if explicitPort && port != "" {
 		// Strip existing brackets before calling JoinHostPort, which automatically adds
 		// brackets for IPv6 addresses. This prevents double-bracketing like [[::1]]:8080.
 		// Using Trim handles both well-formed and malformed bracketed hosts.
@@ -843,7 +832,7 @@ func extractHostHeader(r *http.Request) string {
 		return net.JoinHostPort(host, port)
 	}
 
-	// No port or default port was stripped. According to AWS SDK behavior (aws-sdk-go-v2),
+	// No explicit port was provided (or port was empty). According to AWS SDK behavior (aws-sdk-go-v2),
 	// when a default port is removed from an IPv6 address, the brackets should also be removed.
 	// This matches AWS S3 signature calculation requirements.
 	// Reference: https://github.com/aws/aws-sdk-go-v2/blob/main/aws/signer/internal/v4/host.go
@@ -855,21 +844,6 @@ func extractHostHeader(r *http.Request) string {
 	return host
 }
 
-func isDefaultPort(scheme, port string) bool {
-	if port == "" {
-		return true
-	}
-
-	switch port {
-	case "80":
-		return strings.EqualFold(scheme, "http")
-	case "443":
-		return strings.EqualFold(scheme, "https")
-	default:
-		return false
-	}
-}
-
 // getScope generate a string of a specific date, an AWS region, and a service.
 func getScope(t time.Time, region string, service string) string {
 	scope := strings.Join([]string{

weed/s3api/auth_signature_v4_test.go

@@ -208,7 +208,7 @@ func TestExtractHostHeader(t *testing.T) {
 			forwardedHost:  "example.com",
 			forwardedPort:  "80",
 			forwardedProto: "http",
-			expected:       "example.com",
+			expected:       "example.com:80",
 		},
 		{
 			name:           "X-Forwarded-Host with X-Forwarded-Port (HTTPS standard port 443)",
@@ -216,7 +216,7 @@ func TestExtractHostHeader(t *testing.T) {
 			forwardedHost:  "example.com",
 			forwardedPort:  "443",
 			forwardedProto: "https",
-			expected:       "example.com",
+			expected:       "example.com:443",
 		},
 		// Issue #6649: X-Forwarded-Host already contains port (Traefik/HAProxy style)
 		{
@@ -227,6 +227,14 @@ func TestExtractHostHeader(t *testing.T) {
 			forwardedProto: "https",
 			expected:       "127.0.0.1:8433",
 		},
+		{
+			name:           "X-Forwarded-Host with standard port already included (HTTPS 443)",
+			hostHeader:     "backend:8333",
+			forwardedHost:  "example.com:443",
+			forwardedPort:  "443",
+			forwardedProto: "https",
+			expected:       "example.com:443",
+		},
 		{
 			name:           "X-Forwarded-Host with port, no X-Forwarded-Port header",
 			hostHeader:     "backend:8333",
@@ -253,20 +261,20 @@ func TestExtractHostHeader(t *testing.T) {
 			expected:       "[::1]:8080",
 		},
 		{
-			name:           "IPv6 address without brackets and standard port, should strip brackets per AWS SDK",
+			name:           "IPv6 address without brackets and standard port, should include brackets and port when explicit",
 			hostHeader:     "backend:8333",
 			forwardedHost:  "::1",
 			forwardedPort:  "80",
 			forwardedProto: "http",
-			expected:       "::1",
+			expected:       "[::1]:80",
 		},
 		{
-			name:           "IPv6 address without brackets and standard HTTPS port, should strip brackets per AWS SDK",
+			name:           "IPv6 address without brackets and standard HTTPS port, should include brackets and port when explicit",
 			hostHeader:     "backend:8333",
 			forwardedHost:  "2001:db8::1",
 			forwardedPort:  "443",
 			forwardedProto: "https",
-			expected:       "2001:db8::1",
+			expected:       "[2001:db8::1]:443",
 		},
 		{
 			name:           "IPv6 address with brackets but no port, should add port",
@@ -277,12 +285,12 @@ func TestExtractHostHeader(t *testing.T) {
 			expected:       "[2001:db8::1]:8080",
 		},
 		{
-			name:           "IPv6 full address with brackets and default port (should strip port and brackets)",
+			name:           "IPv6 full address with brackets and default port (should preserve port if explicit)",
 			hostHeader:     "backend:8333",
 			forwardedHost:  "[2001:db8:85a3::8a2e:370:7334]:443",
 			forwardedPort:  "443",
 			forwardedProto: "https",
-			expected:       "2001:db8:85a3::8a2e:370:7334",
+			expected:       "[2001:db8:85a3::8a2e:370:7334]:443",
 		},
 		{
 			name:           "IPv4-mapped IPv6 address without brackets, should add brackets with port",

weed/s3api/auto_signature_v4_test.go

@@ -415,13 +415,13 @@ func TestSignatureV4WithoutProxy(t *testing.T) {
 			name:         "HTTP with standard port",
 			host:         "backend:80",
 			proto:        "http",
-			expectedHost: "backend",
+			expectedHost: "backend:80",
 		},
 		{
 			name:         "HTTPS with standard port",
 			host:         "backend:443",
 			proto:        "https",
-			expectedHost: "backend",
+			expectedHost: "backend:443",
 		},
 		{
 			name:         "HTTP without port",
@@ -451,13 +451,13 @@ func TestSignatureV4WithoutProxy(t *testing.T) {
 			name:         "IPv6 HTTP with standard port",
 			host:         "[::1]:80",
 			proto:        "http",
-			expectedHost: "::1",
+			expectedHost: "[::1]:80",
 		},
 		{
 			name:         "IPv6 HTTPS with standard port",
 			host:         "[::1]:443",
 			proto:        "https",
-			expectedHost: "::1",
+			expectedHost: "[::1]:443",
 		},
 		{
 			name:         "IPv6 HTTP without port",