From: Philipp <philipp+openbsd@bureaucracy.de>
Subject: Re: smtpd: correct remove return-path on enqueue
To: tech@openbsd.org
Date: Sat, 01 Mar 2025 19:01:18 +0100

Ping

Philipp

[2025-01-08 06:22] Philipp <philipp@bureaucracy.de>
> [2025-01-04 07:11] Philipp <philipp+openbsd@bureaucracy.de>
> > When the sendmail binary is used to enqueue a mail the return-path field
> > is be removed. This is not correct implemented. When the field is foldet
> > only the first line of the field is removed. A patch fixing the bug
> > is attached.
>
> I have noticed an other bug in this function. When the return-path value
> doesn't start with an optional space the field is not filtered. Here is
> an updated patch.
>
> Philipp
>
> diff --git a/usr.sbin/smtpd/enqueue.c b/usr.sbin/smtpd/enqueue.c
> index 0dc0ffae1a6..19ef2cbe328 100644
> --- a/usr.sbin/smtpd/enqueue.c
> +++ b/usr.sbin/smtpd/enqueue.c
> @@ -180,6 +180,7 @@ enqueue(int argc, char *argv[], FILE *ofp)
>  	ssize_t			 len;
>  	char			*line;
>  	int			 inheaders = 1;
> +	int			 remove_rpath = 0;
>  	int			 save_argc;
>  	char			**save_argv;
>  	int			 no_getlogin = 0;
> @@ -401,10 +402,15 @@ enqueue(int argc, char *argv[], FILE *ofp)
>  		line = buf;
>  
>  		if (inheaders) {
> +			if (remove_rpath && (line[0] == ' ' || line[0] == '\t'))
> +				continue;
>  			if (strncasecmp("from ", line, 5) == 0)
>  				continue;
> -			if (strncasecmp("return-path: ", line, 13) == 0)
> +			if (strncasecmp("return-path:", line, 12) == 0) {
> +				remove_rpath = 1;
>  				continue;
> +			}
> +			remove_rpath = 0;
>  		}
>  
>  		if (msg.saw_content_transfer_encoding || msg.noheader ||