commit - 4525f6dfc124f7f28ef2bca450dcc8500826d19f
commit + 3f1c295feef22d2d6550dc7686e2c0f94b67d306
blob - cdb04f1eb0e6eb9a341ed47e3194baaca28fb0d0
blob + b45081129b7477a642f044e465c62d7861fb925e
--- config.c
+++ config.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: config.c,v 1.66 2025/11/12 11:24:04 deraadt Exp $	*/
+/*	$OpenBSD: config.c,v 1.67 2025/11/28 16:10:00 rsadowski Exp $	*/
 
 /*
  * Copyright (c) 2011 - 2015 Reyk Floeter <reyk@openbsd.org>
@@ -638,6 +638,8 @@ config_getserver_config(struct httpd *env, struct serv
 		(void)strlcpy(srv_conf->errdocroot, parent->errdocroot,
 		    sizeof(srv_conf->errdocroot));
 
+		srv_conf->flags |= parent->flags & SRVFLAG_NO_BANNER;
+
 		DPRINTF("%s: %s %d location \"%s\", "
 		    "parent \"%s[%u]\", flags: %s",
 		    __func__, ps->ps_title[privsep_process], ps->ps_instance,
blob - 79411a7e9412ede10e4e3f21d9f613badff5f83e
blob + b3673284e0b855fda9441b79a742105ba54610a0
--- httpd.conf.5
+++ httpd.conf.5
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: httpd.conf.5,v 1.127 2025/07/08 14:26:45 schwarze Exp $
+.\"	$OpenBSD: httpd.conf.5,v 1.128 2025/11/28 16:10:00 rsadowski Exp $
 .\"
 .\" Copyright (c) 2014, 2015 Reyk Floeter <reyk@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: July 8 2025 $
+.Dd $Mdocdate: November 28 2025 $
 .Dt HTTPD.CONF 5
 .Os
 .Sh NAME
@@ -171,6 +171,14 @@ If not specified, it defaults to
 within the
 .Xr chroot 2
 directory.
+.It Ic no banner
+Do not send the
+.Va Server
+HTTP response header, and hide the server software name in error documents.
+The
+.Va SERVER_SOFTWARE
+CGI environment variable is always set in accordance with
+.%R RFC 3875 .
 .It Ic prefork Ar number
 Run the specified number of server processes.
 This increases the performance and prevents delays when connecting
@@ -232,6 +240,20 @@ and must be readable by the www user.
 Use the
 .Ic no authenticate
 directive to disable authentication in a location.
+.It Oo Ic no Oc Ic banner
+When prefixed with the
+.Ic no
+keyword,
+suppress the
+.Va Server
+HTTP response header, and hide the server software name in error documents for
+the current
+.Ic server.
+If
+.Ic no
+is omitted, enable the banner for the current
+.Ic server
+if it was disabled globally.
 .It Ic block drop
 Drop the connection without sending an error page.
 .It Ic block Op Ic return Ar code Op Ar uri
@@ -478,6 +500,7 @@ and for generic ones later on.
 A location section may include most of the server configuration rules
 except
 .Ic alias ,
+.Ic banner ,
 .Ic connection ,
 .Ic errdocs ,
 .Ic hsts ,
blob - 40bcaf6cf35f88c031ff9d8566e66ac290253571
blob + baf11d1b52348e7ff1881be81e9f7ee1cd7cda3f
--- httpd.h
+++ httpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: httpd.h,v 1.166 2025/11/27 15:22:45 rsadowski Exp $	*/
+/*	$OpenBSD: httpd.h,v 1.167 2025/11/28 16:10:00 rsadowski Exp $	*/
 
 /*
  * Copyright (c) 2006 - 2015 Reyk Floeter <reyk@openbsd.org>
@@ -389,6 +389,7 @@ SPLAY_HEAD(client_tree, client);
 #define SRVFLAG_PATH_REWRITE	0x01000000
 #define SRVFLAG_NO_PATH_REWRITE	0x02000000
 #define SRVFLAG_GZIP_STATIC	0x04000000
+#define SRVFLAG_NO_BANNER	0x08000000
 #define SRVFLAG_LOCATION_FOUND	0x40000000
 #define SRVFLAG_LOCATION_NOT_FOUND 0x80000000
 
@@ -398,7 +399,7 @@ SPLAY_HEAD(client_tree, client);
 	"\14SYSLOG\15NO_SYSLOG\16TLS\17ACCESS_LOG\20ERROR_LOG"		\
 	"\21AUTH\22NO_AUTH\23BLOCK\24NO_BLOCK\25LOCATION_MATCH"		\
 	"\26SERVER_MATCH\27SERVER_HSTS\30DEFAULT_TYPE\31PATH_REWRITE"	\
-	"\32NO_PATH_REWRITE\33GZIP_STATIC\37LOCATION_FOUND"		\
+	"\32NO_PATH_REWRITE\34NO_BANNER\33GZIP_STATIC\37LOCATION_FOUND"	\
 	"\40LOCATION_NOT_FOUND"
 
 #define TCPFLAG_NODELAY		0x01
blob - d565e61d727d98a0d09ed2a19fd08e608aff3298
blob + 326b249662f3eb72fc53110facb2f4df953932a7
--- parse.y
+++ parse.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.129 2025/11/12 11:24:04 deraadt Exp $	*/
+/*	$OpenBSD: parse.y,v 1.130 2025/11/28 16:10:00 rsadowski Exp $	*/
 
 /*
  * Copyright (c) 2020 Matthias Pressfreund <mpfr@fn.de>
@@ -141,7 +141,7 @@ typedef struct {
 %token	TIMEOUT TLS TYPE TYPES HSTS MAXAGE SUBDOMAINS DEFAULT PRELOAD REQUEST
 %token	ERROR INCLUDE AUTHENTICATE WITH BLOCK DROP RETURN PASS REWRITE
 %token	CA CLIENT CRL OPTIONAL PARAM FORWARDED FOUND NOT
-%token	ERRDOCS GZIPSTATIC
+%token	ERRDOCS GZIPSTATIC BANNER
 %token	<v.string>	STRING
 %token  <v.number>	NUMBER
 %type	<v.port>	port
@@ -227,6 +227,9 @@ main		: PREFORK NUMBER	{
 		| LOGDIR STRING		{
 			conf->sc_logdir = $2;
 		}
+		| NO BANNER		{
+			conf->sc_flags |= SRVFLAG_NO_BANNER;
+		}
 		| DEFAULT TYPE mediastring	{
 			memcpy(&conf->sc_default_type, &media,
 			    sizeof(struct media_type));
@@ -300,6 +303,9 @@ server		: SERVER optmatch STRING	{
 
 			s->srv_conf.hsts_max_age = SERVER_HSTS_DEFAULT_AGE;
 
+			if (conf->sc_flags & SRVFLAG_NO_BANNER)
+				s->srv_conf.flags |= SRVFLAG_NO_BANNER;
+
 			(void)strlcpy(s->srv_conf.errdocroot,
 			    conf->sc_errdocroot,
 			    sizeof(s->srv_conf.errdocroot));
@@ -550,6 +556,7 @@ serveroptsl	: LISTEN ON STRING opttls port	{
 		| request
 		| root
 		| directory
+		| banner
 		| logformat
 		| fastcgi
 		| authenticate
@@ -687,6 +694,22 @@ serveroptsl	: LISTEN ON STRING opttls port	{
 		}
 		;
 
+banner		: BANNER		{
+			if (parentsrv != NULL) {
+				yyerror("banner inside location");
+				YYERROR;
+			}
+			srv->srv_conf.flags &= ~SRVFLAG_NO_BANNER;
+		}
+		| NO BANNER		{
+			if (parentsrv != NULL) {
+				yyerror("no banner inside location");
+				YYERROR;
+			}
+			srv->srv_conf.flags |= SRVFLAG_NO_BANNER;
+		}
+		;
+
 optfound	: /* empty */	{ $$ = 0; }
 		| FOUND		{ $$ = 1; }
 		| NOT FOUND	{ $$ = -1; }
@@ -1428,6 +1451,7 @@ lookup(char *s)
 		{ "authenticate",	AUTHENTICATE},
 		{ "auto",		AUTO },
 		{ "backlog",		BACKLOG },
+		{ "banner",		BANNER },
 		{ "block",		BLOCK },
 		{ "body",		BODY },
 		{ "buffer",		BUFFER },
blob - 70bd78c082028e15efdf2a577dad13c64440ba0f
blob + f3c01a459b08fdaba7be5db1ec4b9ec3cdf68862
--- server_fcgi.c
+++ server_fcgi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: server_fcgi.c,v 1.97 2023/11/08 19:19:10 millert Exp $	*/
+/*	$OpenBSD: server_fcgi.c,v 1.98 2025/11/28 16:10:00 rsadowski Exp $	*/
 
 /*
  * Copyright (c) 2014 Florian Obser <florian@openbsd.org>
@@ -345,6 +345,7 @@ server_fcgi(struct httpd *env, struct client *clt)
 		goto fail;
 	}
 
+	/* RFC 3875 requires this variable always be present */
 	if (fcgi_add_param(&param, "SERVER_SOFTWARE", HTTPD_SERVERNAME,
 	    clt) == -1) {
 		errstr = "failed to encode param";
@@ -659,9 +660,12 @@ server_fcgi_header(struct client *clt, unsigned int co
 	    kv_set(&resp->http_pathquery, "%s", error) == -1)
 		return (-1);
 
-	/* Add headers */
-	if (kv_add(&resp->http_headers, "Server", HTTPD_SERVERNAME) == NULL)
-		return (-1);
+	/* Add server banner header to response unless suppressed */
+	if ((srv_conf->flags & SRVFLAG_NO_BANNER) == 0) {
+		if (kv_add(&resp->http_headers, "Server",
+		    HTTPD_SERVERNAME) == NULL)
+			return (-1);
+	}
 
 	if (clt->clt_fcgi.type == FCGI_END_REQUEST ||
 	    EVBUFFER_LENGTH(clt->clt_srvevb) == 0) {
blob - aef4e4567fc7544b0d99f5a54799b5a171bd7734
blob + f6412e80bf7e93b6807b4c66464c6782713e3747
--- server_http.c
+++ server_http.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: server_http.c,v 1.155 2024/12/22 13:51:42 florian Exp $	*/
+/*	$OpenBSD: server_http.c,v 1.156 2025/11/28 16:10:00 rsadowski Exp $	*/
 
 /*
  * Copyright (c) 2020 Matthias Pressfreund <mpfr@fn.de>
@@ -890,6 +890,7 @@ server_abort_http(struct client *clt, unsigned int cod
 	char			*httpmsg, *body = NULL, *extraheader = NULL;
 	char			 tmbuf[32], hbuf[128], *hstsheader = NULL;
 	char			*clenheader = NULL;
+	char			*bannerheader = NULL, *bannertoken = NULL;
 	char			 buf[IBUF_READ_SIZE];
 	char			*escapedmsg = NULL;
 	char			 cstr[5];
@@ -981,7 +982,11 @@ server_abort_http(struct client *clt, unsigned int cod
 
 	body = replace_var(body, "$HTTP_ERROR", httperr);
 	body = replace_var(body, "$RESPONSE_CODE", cstr);
-	body = replace_var(body, "$SERVER_SOFTWARE", HTTPD_SERVERNAME);
+	/* Check if server banner is suppressed */
+	if ((srv_conf->flags & SRVFLAG_NO_BANNER) == 0)
+		body = replace_var(body, "$SERVER_SOFTWARE", HTTPD_SERVERNAME);
+	else
+		body = replace_var(body, "$SERVER_SOFTWARE", "");
 	bodylen = strlen(body);
 	goto send;
 
@@ -994,6 +999,14 @@ server_abort_http(struct client *clt, unsigned int cod
 	    "body { background-color: #1E1F21; color: #EEEFF1; }\n"
 	    "a { color: #BAD7FF; }\n}";
 
+	/* If banner is suppressed, don't write it to the error document */
+	if ((srv_conf->flags & SRVFLAG_NO_BANNER) == 0)
+		if (asprintf(&bannertoken, "<hr>\n<address>%s</address>\n",
+		    HTTPD_SERVERNAME) == -1) {
+			bannertoken = NULL;
+			goto done;
+		}
+
 	/* Generate simple HTML error document */
 	if ((bodylen = asprintf(&body,
 	    "<!DOCTYPE html>\n"
@@ -1005,10 +1018,11 @@ server_abort_http(struct client *clt, unsigned int cod
 	    "</head>\n"
 	    "<body>\n"
 	    "<h1>%03d %s</h1>\n"
-	    "<hr>\n<address>%s</address>\n"
+	    "%s"
 	    "</body>\n"
 	    "</html>\n",
-	    code, httperr, style, code, httperr, HTTPD_SERVERNAME)) == -1) {
+	    code, httperr, style, code, httperr,
+	    bannertoken == NULL ? "" : bannertoken)) == -1) {
 		body = NULL;
 		goto done;
 	}
@@ -1037,11 +1051,19 @@ server_abort_http(struct client *clt, unsigned int cod
 		}
 	}
 
+	/* If banner is suppressed, don't write a Server header */
+	if ((srv_conf->flags & SRVFLAG_NO_BANNER) == 0)
+		if (asprintf(&bannerheader, "Server: %s\r\n",
+		    HTTPD_SERVERNAME) == -1) {
+			bannerheader = NULL;
+			goto done;
+		}
+
 	/* Add basic HTTP headers */
 	if (asprintf(&httpmsg,
 	    "HTTP/1.0 %03d %s\r\n"
 	    "Date: %s\r\n"
-	    "Server: %s\r\n"
+	    "%s"
 	    "Connection: close\r\n"
 	    "Content-Type: text/html\r\n"
 	    "%s"
@@ -1049,7 +1071,8 @@ server_abort_http(struct client *clt, unsigned int cod
 	    "%s"
 	    "\r\n"
 	    "%s",
-	    code, httperr, tmbuf, HTTPD_SERVERNAME,
+	    code, httperr, tmbuf,
+	    bannerheader == NULL ? "" : bannerheader,
 	    clenheader == NULL ? "" : clenheader,
 	    extraheader == NULL ? "" : extraheader,
 	    hstsheader == NULL ? "" : hstsheader,
@@ -1066,6 +1089,8 @@ server_abort_http(struct client *clt, unsigned int cod
 	free(extraheader);
 	free(hstsheader);
 	free(clenheader);
+	free(bannerheader);
+	free(bannertoken);
 	if (msg == NULL)
 		msg = "\"\"";
 	if (asprintf(&httpmsg, "%s (%03d %s)", msg, code, httperr) == -1) {
@@ -1558,10 +1583,12 @@ server_response_http(struct client *clt, unsigned int 
 	    kv_set(&resp->http_pathquery, "%s", error) == -1)
 		return (-1);
 
-	/* Add headers */
-	if (kv_add(&resp->http_headers, "Server", HTTPD_SERVERNAME) == NULL)
-		return (-1);
-
+	/* Add server banner header to response unless suppressed */
+	if ((srv_conf->flags & SRVFLAG_NO_BANNER) == 0) {
+		if (kv_add(&resp->http_headers, "Server",
+		    HTTPD_SERVERNAME) == NULL)
+			return (-1);
+	}
 	/* Is it a persistent connection? */
 	if (clt->clt_persist) {
 		if (kv_add(&resp->http_headers,