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From:
Kirill A. Korinsky <kirill@korins.ky>
Subject:
Re: (return of) the httpd banner suppressing patch
To:
Rafael Sadowski <rafael@sizeofvoid.org>
Cc:
Lloyd <ng2d68@proton.me>, "tech@openbsd.org" <tech@openbsd.org>
Date:
Thu, 27 Nov 2025 21:15:47 +0100

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On Thu, 27 Nov 2025 21:03:25 +0100,
Rafael Sadowski <rafael@sizeofvoid.org> wrote:
> 
> On Tue May 13, 2025 at 08:59:37PM +0000, Lloyd wrote:
> > Henry Ford wrote:
> > 
> > > I have a few comments on this
> > >
> > > This directive should be listed along with the other directives that
> > > are not allowed in location blocks in the httpd.conf(5) manpage.
> > 
> > Good catch, thanks for giving this a deeper look.
> > 
> > > Since HTTPD_SERVERNAME is a constant I don't think you really need
> > > to use asprintf(3) here (could just use string literal concatenation).
> > >
> > > If if makes sense to use asprintf(3) here then you should check
> > > if it fails, and at some point free bannertoken.
> > >
> > 
> > Looking back, when I first developed the patch the servername was a
> > user configurable string. I later ripped that out and reverted to a
> > simple on/off condition of the banner. That said, the use of asprintf
> > is consistent with all the adjacent code and is a little bit cleaner
> > visually, but you're correct there was a missing free() in there.
> > 
> > As for checking for failure on asprintf, OpenBSD should set the value
> > of the pointer to NULL on error anyway which is checked later; however,
> > other OSes don't make that guarantee. E.g. Linux claims the value of
> > the pointer becomes undefined. So I would agree the additional check
> > and redundant setting the pointer to NULL does become prudent.
> > 
> > Thanks for the feedback, a revised patch can be found below.
> > 
> > Regards
> > Lloyd
> > 
> 
> Hi Lloyd, Hi Kirill,
> 
> some comments in-line. At the very bottom, a diff revised with the
> in-line changes and after GZIPSTATIC commit from today.
> 
> Kirill are you sill OK with this diff? For you too Lloyd?
>

Yes, it reads OK kirill@, I haven't tested the last version nor compiled it,
but it reads like it should work.

> Thanks,
> 
> Rafael
> 
> 
> > Index: config.c
> > ===================================================================
> > RCS file: /cvs/src/usr.sbin/httpd/config.c,v
> > retrieving revision 1.65
> > diff -u -p -u -p -r1.65 config.c
> > --- config.c	17 Jan 2024 08:22:40 -0000	1.65
> > +++ config.c	13 May 2025 20:44:43 -0000
> > @@ -591,6 +591,8 @@ config_getserver_config(struct httpd *en
> >  		srv_conf->flags |= parent->flags & SRVFLAG_ERRDOCS;
> >  		(void)strlcpy(srv_conf->errdocroot, parent->errdocroot,
> >  		    sizeof(srv_conf->errdocroot));
> > +		
> 
> Deleted extra whitespaces.
> 
> > +		srv_conf->flags |= parent->flags & SRVFLAG_NO_BANNER;
> >  
> >  		DPRINTF("%s: %s %d location \"%s\", "
> >  		    "parent \"%s[%u]\", flags: %s",
> > Index: httpd.conf.5
> > ===================================================================
> > RCS file: /cvs/src/usr.sbin/httpd/httpd.conf.5,v
> > retrieving revision 1.125
> > diff -u -p -u -p -r1.125 httpd.conf.5
> > --- httpd.conf.5	3 Nov 2023 13:03:02 -0000	1.125
> > +++ httpd.conf.5	13 May 2025 20:44:43 -0000
> > @@ -166,6 +166,14 @@ 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
> > @@ -227,6 +235,20 @@ 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
> > @@ -473,6 +495,7 @@ 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 ,
> > Index: httpd.h
> > ===================================================================
> > RCS file: /cvs/src/usr.sbin/httpd/httpd.h,v
> > retrieving revision 1.165
> > diff -u -p -u -p -r1.165 httpd.h
> > --- httpd.h	8 Oct 2024 05:28:11 -0000	1.165
> > +++ httpd.h	13 May 2025 20:44:43 -0000
> > @@ -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\32NO_PATH" \
> > -	"\37LOCATION_FOUND\40LOCATION_NOT_FOUND"
> > +	"\33GZIP_STATIC\34NO_BANNER\37LOCATION_FOUND\40LOCATION_NOT_FOUND"
> >  
> >  #define TCPFLAG_NODELAY		0x01
> >  #define TCPFLAG_NNODELAY	0x02
> > Index: parse.y
> > ===================================================================
> > RCS file: /cvs/src/usr.sbin/httpd/parse.y,v
> > retrieving revision 1.128
> > diff -u -p -u -p -r1.128 parse.y
> > --- parse.y	27 Feb 2022 20:30:30 -0000	1.128
> > +++ parse.y	13 May 2025 20:44:43 -0000
> > @@ -141,9 +141,9 @@ 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
> > +%token	<v.number>	NUMBER
> 
> Deleted, I will commit that separately.
> 
> >  %type	<v.port>	port
> >  %type	<v.string>	fcgiport
> >  %type	<v.number>	opttls optmatch optfound
> > @@ -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 po
> >  		| request
> >  		| root
> >  		| directory
> > +		| banner
> >  		| logformat
> >  		| fastcgi
> >  		| authenticate
> > @@ -687,6 +694,22 @@ serveroptsl	: LISTEN ON STRING opttls po
> >  		}
> >  		;
> >  
> > +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 },
> > Index: server_fcgi.c
> > ===================================================================
> > RCS file: /cvs/src/usr.sbin/httpd/server_fcgi.c,v
> > retrieving revision 1.97
> > diff -u -p -u -p -r1.97 server_fcgi.c
> > --- server_fcgi.c	8 Nov 2023 19:19:10 -0000	1.97
> > +++ server_fcgi.c	13 May 2025 20:44:43 -0000
> > @@ -345,6 +345,7 @@ server_fcgi(struct httpd *env, struct cl
> >  		goto fail;
> >  	}
> >  
> > +	/* RFC 3875 requires this variable always be present */
> 
> Deleted. I don't find that helpful; otherwise, you would have to
> write that for all variables.
> 
> >  	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, u
> >  	    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);
> > +	}	
> 
> Deleted extra whitespaces.
> 
> >  
> >  	if (clt->clt_fcgi.type == FCGI_END_REQUEST ||
> >  	    EVBUFFER_LENGTH(clt->clt_srvevb) == 0) {
> > Index: server_http.c
> > ===================================================================
> > RCS file: /cvs/src/usr.sbin/httpd/server_http.c,v
> > retrieving revision 1.155
> > diff -u -p -u -p -r1.155 server_http.c
> > --- server_http.c	22 Dec 2024 13:51:42 -0000	1.155
> > +++ server_http.c	13 May 2025 20:44:43 -0000
> > @@ -890,6 +890,7 @@ server_abort_http(struct client *clt, un
> >  	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, un
> >  
> >  	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, un
> >  	    "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, un
> >  	    "</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, un
> >  		}
> >  	}
> >  
> > +	/* 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, un
> >  	    "%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, un
> >  	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,
> >  	    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,
> > 
> > 
> 
> 
> 
> diff --git a/usr.sbin/httpd/config.c b/usr.sbin/httpd/config.c
> index cdb04f1eb0e..f2dc4bb63f2 100644
> --- a/usr.sbin/httpd/config.c
> +++ b/usr.sbin/httpd/config.c
> @@ -638,6 +638,8 @@ config_getserver_config(struct httpd *env, struct server *srv,
>  		(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,
> diff --git a/usr.sbin/httpd/httpd.conf.5 b/usr.sbin/httpd/httpd.conf.5
> index 79411a7e941..fa6c76b26f8 100644
> --- a/usr.sbin/httpd/httpd.conf.5
> +++ b/usr.sbin/httpd/httpd.conf.5
> @@ -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 ,
> diff --git a/usr.sbin/httpd/httpd.h b/usr.sbin/httpd/httpd.h
> index 40bcaf6cf35..f3eec1d28ea 100644
> --- a/usr.sbin/httpd/httpd.h
> +++ b/usr.sbin/httpd/httpd.h
> @@ -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
> diff --git a/usr.sbin/httpd/parse.y b/usr.sbin/httpd/parse.y
> index d565e61d727..a422cde7823 100644
> --- a/usr.sbin/httpd/parse.y
> +++ b/usr.sbin/httpd/parse.y
> @@ -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 },
> diff --git a/usr.sbin/httpd/server_fcgi.c b/usr.sbin/httpd/server_fcgi.c
> index 70bd78c0820..7c436654e0d 100644
> --- a/usr.sbin/httpd/server_fcgi.c
> +++ b/usr.sbin/httpd/server_fcgi.c
> @@ -659,9 +659,12 @@ server_fcgi_header(struct client *clt, unsigned int code)
>  	    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) {
> diff --git a/usr.sbin/httpd/server_http.c b/usr.sbin/httpd/server_http.c
> index aef4e4567fc..6d7d2e3251a 100644
> --- a/usr.sbin/httpd/server_http.c
> +++ b/usr.sbin/httpd/server_http.c
> @@ -890,6 +890,7 @@ server_abort_http(struct client *clt, unsigned int code, const char *msg)
>  	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 code, const char *msg)
>  
>  	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 code, const char *msg)
>  	    "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 code, const char *msg)
>  	    "</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 code, const char *msg)
>  		}
>  	}
>  
> +	/* 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 code, const char *msg)
>  	    "%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 code, const char *msg)
>  	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 code,
>  	    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,

-- 
wbr, Kirill