From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, HTML_FONT_LOW_CONTRAST,HTML_MESSAGE,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 5145 invoked from network); 15 Nov 2021 18:31:47 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 15 Nov 2021 18:31:47 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 0AD4F9C7AB; Tue, 16 Nov 2021 04:31:28 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id A60D39C6A6; Tue, 16 Nov 2021 04:30:59 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=ccc.com header.i=@ccc.com header.b="aD3F197v"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 76B4E9BCFF; Tue, 16 Nov 2021 04:29:56 +1000 (AEST) Received: from mail-oi1-f181.google.com (mail-oi1-f181.google.com [209.85.167.181]) by minnie.tuhs.org (Postfix) with ESMTPS id 6D0009C1E1 for ; Tue, 16 Nov 2021 04:29:54 +1000 (AEST) Received: by mail-oi1-f181.google.com with SMTP id t23so5257872oiw.3 for ; Mon, 15 Nov 2021 10:29:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ccc.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=QpYvTdQ7jkxYRig7nWcyVrzqcT3DQUWtXJ9vLcpCLMg=; b=aD3F197vYptO8rovXrQwMOXm3zLOTJn/SDZjoPIC4DAq/XWxz8kPFl01Rk6FYmmBfQ sw4y08Ek+70SeOeabQpAU3HoEni3dxxhTcwQLmbTfrKTRaGcpJHiQv6hlmUu5Rtfmwsr ggX64pYkwFVo8bKM8Smj0s46mSPuvGzvmInJQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=QpYvTdQ7jkxYRig7nWcyVrzqcT3DQUWtXJ9vLcpCLMg=; b=DZt/WeFR5YKgJ1VrJJOnds0tQGObdYtblgEaBE+qq8FWmN7PlR6nTlsG8d+sSddtPN NMz99jbroOX/oNGMsi/wX8UziBrwm7J5IGBBui6z3/MkwJWlmNx7m8IJ3txGGbTrlK7i oX5WxwE19c/fyS2lhYcC4OSsyTQw/1mHo7pf6WX5Rb8sIMzdNq1IES8ZkF5aNNWqXOTS RTHBTeYm3eF+QR1/M0KI3QjSsjs2NRwLUmE7K2PDoBw7kFVIqxwxSBHiGzqwWpcQkXeF /7VEYPJYBuIYNENWyMvptQX76CqTuC3zGHMob2crlqrhl7R5uGBfxMUwUM3AoxKg796e yYsg== X-Gm-Message-State: AOAM533WNBC3efvn0NMWdo6I2vFB9IY2zRqowWik78bLBwYKCx26KlYd OzgmRfEuVMylkGWHXztOdP3faz9oIYxzA7OVI1TueaWvJLQ= X-Google-Smtp-Source: ABdhPJz2MkTUanmvaZtXS+DeB/7spFBcIYPs9QoOkxr5c96OIAgxZeWp+qLn40tMnlGpUUuJAJ92K/hnEMmdT+48b8k= X-Received: by 2002:aca:c45:: with SMTP id i5mr47874972oiy.176.1637000993583; Mon, 15 Nov 2021 10:29:53 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Clem Cole Date: Mon, 15 Nov 2021 13:29:29 -0500 Message-ID: To: Grant Taylor Subject: Re: [COFF] Will someone please explain the history and usage of gpasswd / newgrp / sg? X-BeenThere: coff@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: Computer Old Farts Forum List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: The Unix Heritage Society , COFF Content-Type: multipart/mixed; boundary="===============6841078780763685017==" Errors-To: coff-bounces@minnie.tuhs.org Sender: "COFF" --===============6841078780763685017== Content-Type: multipart/alternative; boundary="000000000000b8404005d0d7fe9c" --000000000000b8404005d0d7fe9c Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Grant, Mashey and crew basically did most of the original group work as part of PWB. If you look at the Sixth Edition sources and the PWB 1.0 stuff, that is one of the places you will find differences. With Seventh Edition (or I believe as part of the UNIX/TS work that Ken picked up), the Mashey group changes went back into the Research stream. With one of the predecessors to 4.2BSD (it may have 4.1A or 4.1B but frankly I have forgotten) Joy introduced the group scheme we all use today. The Mashey scheme allowed an UID to be assigned to multiple groups, but only use (be in) a single group during the process lifetime. IIRC the RJE system was based on it, but there were some other scripts that the PWB team needed. Check the original PWB docs, there is some explanation of them. FWIW: new group was added to be similar to switch user (su), to change the gid when the setguid bit was not set on the file. The truth is the early group stuff was not used by most admins. With BSD and use of UNIX for large systems (particularly academic teaching systems), the desire to have some processes be in more than one group and be able to test the group file protections accordingly was desired -- for things like creating a group for each class - where the hand in system was write-only to the class's TA who was also part of the group. I'm sure it was used in many other ways, but that was certainly one scheme we used at UCB when wnj added them. Again check the 4.2 docs, where the BSD group scheme is explained. This did seem useful and System V picked it up also fairly soon after BSD released it to the world, and fortunately did not change the BSD semantics. =E1=90=A7 On Mon, Nov 15, 2021 at 11:12 AM Grant Taylor via COFF wrote: > Hi, > > Will someone please explain the history and usage of gpasswd / newgrp / s= g? > > I've run across them again recently while reading old Unix texts. I've > been aware of them for years, but I've never actually used them for > anything beyond kicking the tires. So I figured that I'd inquire of the > hive mind that is TUHS / COFF. > > When was the concept of group passwords introduced? > > What was the problem that group passwords were the solution for? > > How common was the use of group passwords? > > I ran into one comment indicating that they used newgrp to work around a > limitation in the number of (secondary) groups in relation to an NFS > implementation. Specifically that the implementation of NFS they were > using didn't support more than 16 groups. So they would switch their > primary group to work around this limit. > > Does anyone have any interesting stories related to group passwords / > gpasswd / newgrp / sg? > > > > -- > Grant. . . . > unix || die > > _______________________________________________ > COFF mailing list > COFF@minnie.tuhs.org > https://minnie.tuhs.org/cgi-bin/mailman/listinfo/coff > --000000000000b8404005d0d7fe9c Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Grant,

Mashey and crew basically d= id most of the original group work as part of PWB.=C2=A0 =C2=A0If you look = at the Sixth Edition sources and the PWB 1.0 stuff, that is one of the plac= es you will find differences.=C2=A0 With Seventh Edition (or I believe as p= art of the UNIX/TS work that Ken picked up), the Mashey group changes went = back into the Research stream. With one of the predecessors=C2=A0to 4.2BSD = (it may have 4.1A or 4.1B but frankly I have forgotten) Joy introduced the = group scheme we all use today.

The Mashey scheme allow= ed=C2=A0an UID to be assigned to multiple groups, but only use=C2=A0(be in)= a single group during the process lifetime.=C2=A0 IIRC the RJE system was = based on it, but there were some other scripts that the PWB team needed. Ch= eck the original PWB docs, there is some explanation of them.=C2=A0 FWIW: n= ew group was added to be similar to switch user (su), to change=C2=A0the gi= d when the setguid=C2=A0bit was not set on the file.=C2=A0 =C2=A0The truth = is the early group stuff was not used by most admins.

= With BSD and use of UNIX for large systems (particularly academic teaching = systems), the desire to have some processes be in more than one group and b= e able to test the group file protections accordingly was desired -- for th= ings like creating a group for each class - where the hand in system was wr= ite-only to the class's TA who was also part of the group.

=
I'm sure it was used in many other ways, but that was certainl= y one scheme we used at UCB when wnj added them.=C2=A0 Again check the 4.2 = docs, where the BSD group scheme is explained.=C2=A0 =C2=A0This did seem us= eful and System V picked it up also fairly soon after BSD released it to th= e world, and fortunately did not change the BSD semantics.=C2=A0=C2=A0
3D"==E1=90=A7

On Mon, Nov 15, 2021 at 11:12 AM Grant Taylor via= COFF <coff@minnie.tuhs.org&= gt; wrote:
Hi,
Will someone please explain the history and usage of gpasswd / newgrp / sg?=

I've run across them again recently while reading old Unix texts.=C2=A0= I've
been aware of them for years, but I've never actually used them for anything beyond kicking the tires.=C2=A0 So I figured that I'd inquire = of the
hive mind that is TUHS / COFF.

When was the concept of group passwords introduced?

What was the problem that group passwords were the solution for?

How common was the use of group passwords?

I ran into one comment indicating that they used newgrp to work around a limitation in the number of (secondary) groups in relation to an NFS
implementation.=C2=A0 Specifically that the implementation of NFS they were=
using didn't support more than 16 groups.=C2=A0 So they would switch th= eir
primary group to work around this limit.

Does anyone have any interesting stories related to group passwords /
gpasswd / newgrp / sg?



--
Grant. . . .
unix || die

_______________________________________________
COFF mailing list
COFF@minnie.tuhs.= org
https://minnie.tuhs.org/cgi-bin/mailman/listinf= o/coff
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