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diff --git a/sag-0.6.1-www/Invisible/sag-0.6/node89.html b/sag-0.6.1-www/Invisible/sag-0.6/node89.html new file mode 100644 index 0000000..9d32b9e --- /dev/null +++ b/sag-0.6.1-www/Invisible/sag-0.6/node89.html @@ -0,0 +1,63 @@ +<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> +<!--Converted with LaTeX2HTML 96.1-h (September 30, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --> +<HTML> +<HEAD> +<TITLE>/etc/passwd and other informative files</TITLE> +<META NAME="description" CONTENT="/etc/passwd and other informative files"> +<META NAME="keywords" CONTENT="sag"> +<META NAME="resource-type" CONTENT="document"> +<META NAME="distribution" CONTENT="global"> +<LINK REL=STYLESHEET HREF="sag.css"> +</HEAD> +<BODY LANG="EN" > + <A NAME="tex2html1440" HREF="node90.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1438" HREF="node88.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1432" HREF="node88.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1442" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1443" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1441" HREF="node90.html">Picking numeric user and </A> +<B>Up:</B> <A NAME="tex2html1439" HREF="node88.html">Creating a user</A> +<B> Previous:</B> <A NAME="tex2html1433" HREF="node88.html">Creating a user</A> +<BR> <P> +<A NAME="2828"> </A><H2><A NAME="SECTION001021000000000000000"><tt>/etc/passwd</tt> and other informative files</A></H2> +<P> + The basic user database in a Unix system is the text + file, <tt>/etc/passwd</tt><A NAME="2830"> </A> (called the <b>password + file</b>), which lists all valid usernames and their + associated information. The file has one line per + username, and is divided into seven colon-delimited + fields: + <OL> +<LI> Username. +<LI> Password, in an encrypted form. +<LI> Numeric user id. +<LI> Numeric group id. +<LI> Full name or other description of account. +<LI> Home directory. +<LI> Login shell (program to run at login). + </OL> + The format is explained in more detail in <em>passwd</em><A NAME="2833"> </A>(5). +<P> + Any user on the system may read the password file, so that + they can, for example, learn the name of another user. + This means that the password (the second field) is also + available to everyone. The password file encrypts the + password, so in theory there is no problem. However, the + encryption is breakable, especially if the password is weak + (e.g., it is short or it can be found in a dictionary). + Therefore it is not a good idea to have the password in + the password file. +<P> + Many Linux systems have <b>shadow passwords</b>. This is + an alternative way of storing the password: the encrypted + password is stored in a separate file, <tt>/etc/shadow</tt><A NAME="2836"> </A>, + which only <tt>root</tt> can read. The <tt>/etc/passwd</tt><A NAME="2838"> </A> + file only contains a special marker in the second field. + Any program that needs to verify a user is setuid, and + can therefore access the shadow password file. Normal + programs, which only use the other fields in the password + file, can't get at the password.<A NAME="tex2html42" HREF="footnode.html#2816"><IMG ALIGN=BOTTOM ALT="gif" SRC="./foot_motif.gif"></A> +<P> +<BR> <HR> +<P><ADDRESS> +<I>Lars Wirzenius <BR> +Sat Nov 15 02:32:11 EET 1997</I> +</ADDRESS> +</BODY> +</HTML> |