diff options
Diffstat (limited to 'modules/caddyhttp/server.go')
| -rw-r--r-- | modules/caddyhttp/server.go | 42 |
1 files changed, 38 insertions, 4 deletions
diff --git a/modules/caddyhttp/server.go b/modules/caddyhttp/server.go index 05763ba..9f08d1f 100644 --- a/modules/caddyhttp/server.go +++ b/modules/caddyhttp/server.go @@ -7,6 +7,7 @@ import ( "net" "net/http" "strconv" + "strings" "github.com/caddyserver/caddy" "github.com/caddyserver/caddy/modules/caddytls" @@ -25,6 +26,7 @@ type Server struct { TLSConnPolicies caddytls.ConnectionPolicies `json:"tls_connection_policies,omitempty"` AutoHTTPS *AutoHTTPSConfig `json:"automatic_https,omitempty"` MaxRehandles int `json:"max_rehandles,omitempty"` + StrictSNIHost bool `json:"strict_sni_host,omitempty"` // TODO: see if we can turn this on by default when clientauth is configured tlsApp *caddytls.TLS } @@ -47,8 +49,9 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) { addHTTPVarsToReplacer(repl, r, w) // build and execute the main handler chain - stack, w := s.Routes.BuildCompositeRoute(w, r) - err := s.executeCompositeRoute(w, r, stack) + stack, wrappedWriter := s.Routes.BuildCompositeRoute(w, r) + stack = s.wrapPrimaryRoute(stack) + err := s.executeCompositeRoute(wrappedWriter, r, stack) if err != nil { // add the raw error value to the request context // so it can be accessed by error handlers @@ -66,8 +69,8 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) { } if s.Errors != nil && len(s.Errors.Routes) > 0 { - errStack, w := s.Errors.Routes.BuildCompositeRoute(w, r) - err := s.executeCompositeRoute(w, r, errStack) + errStack, wrappedWriter := s.Errors.Routes.BuildCompositeRoute(w, r) + err := s.executeCompositeRoute(wrappedWriter, r, errStack) if err != nil { // TODO: what should we do if the error handler has an error? log.Printf("[ERROR] [%s %s] handling error: %v", r.Method, r.RequestURI, err) @@ -104,6 +107,37 @@ func (s *Server) executeCompositeRoute(w http.ResponseWriter, r *http.Request, s return err } +// wrapPrimaryRoute wraps stack (a compiled middleware handler chain) +// in s.enforcementHandler which performs crucial security checks, etc. +func (s *Server) wrapPrimaryRoute(stack Handler) Handler { + return HandlerFunc(func(w http.ResponseWriter, r *http.Request) error { + return s.enforcementHandler(w, r, stack) + }) +} + +// enforcementHandler is an implicit middleware which performs +// standard checks before executing the HTTP middleware chain. +func (s *Server) enforcementHandler(w http.ResponseWriter, r *http.Request, next Handler) error { + // enforce strict host matching, which ensures that the SNI + // value (if any), matches the Host header; essential for + // servers that rely on TLS ClientAuth sharing a listener + // with servers that do not; if not enforced, client could + // bypass by sending benign SNI then restricted Host header + if s.StrictSNIHost && r.TLS != nil { + hostname, _, err := net.SplitHostPort(r.Host) + if err != nil { + hostname = r.Host // OK; probably lacked port + } + if strings.ToLower(r.TLS.ServerName) != strings.ToLower(hostname) { + err := fmt.Errorf("strict host matching: TLS ServerName (%s) and HTTP Host (%s) values differ", + r.TLS.ServerName, hostname) + r.Close = true + return Error(http.StatusForbidden, err) + } + } + return next.ServeHTTP(w, r) +} + func (s *Server) listenersUseAnyPortOtherThan(otherPort int) bool { for _, lnAddr := range s.Listen { _, addrs, err := parseListenAddr(lnAddr) |