Re: git: 0deb25bd9d6d - main - pwd_mkdb(8): Don't copy comments from /etc/master.passwd to /etc/passwd.

From: Jessica Clarke <jrtc27_at_freebsd.org>
Date: Mon, 30 Jan 2023 03:33:40 UTC
On 5 Jan 2023, at 06:48, Xin LI <delphij@FreeBSD.org> wrote:
> 
> The branch main has been updated by delphij:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=0deb25bd9d6d2cdd4aa22f0e2754161e35f3785c
> 
> commit 0deb25bd9d6d2cdd4aa22f0e2754161e35f3785c
> Author:     Andre Albsmeier <Andre.Albsmeier@siemens.com>
> AuthorDate: 2010-03-11 10:53:47 +0000
> Commit:     Xin LI <delphij@FreeBSD.org>
> CommitDate: 2023-01-05 06:18:09 +0000
> 
>    pwd_mkdb(8): Don't copy comments from /etc/master.passwd to /etc/passwd.
> 
>    The intention of /etc/passwd was to support legacy applications that are
>    not yet converted to use modern API like getpwent(3). Comments are not
>    defined in the legacy format, so copying them could break these
>    applications. Plus, it could leak sensitive information (e.g. encrypted
>    form of password of an user that was commented out instead of deleted
>    or disabled).

This broke usr.sbin/etcupdate/tests/preworld_test.sh.

Jess

>    PR:             bin/144652
>    MFC after:      1 month
> ---
> usr.sbin/pwd_mkdb/pwd_mkdb.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/usr.sbin/pwd_mkdb/pwd_mkdb.c b/usr.sbin/pwd_mkdb/pwd_mkdb.c
> index 6297bcb461db..261e7951a126 100644
> --- a/usr.sbin/pwd_mkdb/pwd_mkdb.c
> +++ b/usr.sbin/pwd_mkdb/pwd_mkdb.c
> @@ -462,11 +462,14 @@ main(int argc, char *argv[])
> 					error("put");
> 			}
> 		}
> -		/* Create original format password file entry */
> -		if (is_comment && makeold){	/* copy comments */
> -			if (fprintf(oldfp, "%s\n", line) < 0)
> -				error("write old");
> -		} else if (makeold) {
> +		/*
> +		 * Create original style password file entry.
> +		 *
> +		 * Don't copy comments since this could reveal encrypted
> +		 * passwords if entries have been simply commented out
> +		 * in master.passwd.
> +		 */
> +		if (makeold && !is_comment) {
> 			char uidstr[20];
> 			char gidstr[20];
>