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Date:      Sun, 11 Nov 2001 06:10:03 -0800 (PST)
From:      Martin Heinen <martin@sumuk.de>
To:        freebsd-doc@freebsd.org
Subject:   Re: docs/31899: Markup changes for chapter Security
Message-ID:  <200111111410.fABEA3N07972@freefall.freebsd.org>

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The following reply was made to PR docs/31899; it has been noted by GNATS.

From: Martin Heinen <martin@sumuk.de>
To: Tom Hukins <tom@FreeBSD.org>
Cc: FreeBSD-gnats-submit@FreeBSD.org
Subject: Re: docs/31899: Markup changes for chapter Security
Date: Sun, 11 Nov 2001 15:06:54 +0100

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 On Sat, Nov 10, 2001 at 05:27:14PM +0000, Tom Hukins wrote:
 > On Sat, Nov 10, 2001 at 03:19:43PM +0100, Martin Heinen wrote:
 > >        <para>If you have installed the DES-capable crypt library
 > > -      <filename>libdescrypt</filename> (e.g. by installing the
 > > -      "crypto" distribution), then which password format will be used
 > > -      for new passwords is controlled by the
 > > -      <quote>passwd_format</quote> login capability in
 > > -      <filename>/etc/login.conf</filename>, which takes values of
 > > -      either <quote>des</quote> or <quote>md5</quote>.  See the
 > > -      &man.login.conf.5; manual page for more information about login
 > > -      capabilities.</para>
 > 
 > Rather than fixing this by modifying the quotes, shouldn't this be
 > totally updated?  We don't have a "crypto" distribution any more, so we
 > should specify what happens by default and explain how to change it.
 
 second uups, in the future I will read the relase notes more
 thoroughly.  The attached diff reformulates the section, but I'm
 not sure if I got this right, especially I don't know when /etc/auth.conf
 is used.  Maybe someone else can shed more light on this.
 
 Should I open a new PR for this issue?
 
 Martin
 -- 
 Marxpitn
 
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 Index: chapter.sgml
 ===================================================================
 RCS file: /u/cvs/doc/en_US.ISO8859-1/books/handbook/security/chapter.sgml,v
 retrieving revision 1.96
 diff -u -r1.96 chapter.sgml
 --- chapter.sgml	2001/10/29 11:02:50	1.96
 +++ chapter.sgml	2001/11/11 13:33:53
 @@ -978,50 +978,35 @@
      <sect2>
        <title>Recognizing Your Crypt Mechanism</title>
  
 +      <para>Before FreeBSD 4.4 <filename>libcrypt.a</filename> was a
 +        symbolic link pointing to the library which was used for
 +	encryption.  FreeBSD 4.4 changed <filename>libcrypt.a</filename> to
 +	provide a configurable password authentication hash library.
 +	Currently the library supports DES, MD5 and Blowfish hash
 +	functions.  By default FreeBSD uses MD5 to encrypt
 +	passwords.</para>
 +
        <para>It is pretty easy to identify which encryption method 
  	FreeBSD is set up to use.  Examining the encrypted passwords in
  	the <filename>/etc/master.passwd</filename> file is one way.
  	Passwords encrypted with the MD5 hash are longer than those
  	encrypted with the DES hash and also begin with the characters
 -	<literal>&dollar;1&dollar;</literal>.  DES password strings do not
 +	<literal>&dollar;1&dollar;</literal>.  Passwords starting with
 +	<literal>&dollar;2&dollar;</literal> are encrypted with the
 +	Blowfish hash function. DES password strings do not
  	have any particular identifying characteristics, but they are
  	shorter than MD5 passwords, and are coded in a 64-character
  	alphabet which does not include the <literal>&dollar;</literal>
  	character, so a relatively short string which does not begin with
  	a dollar sign is very likely a DES password.</para>
 -
 -      <para>The libraries can identify the passwords this way as well.
 -	As a result, the DES libraries are able to identify MD5
 -	passwords, and use MD5 to check passwords that were encrypted
 -	that way, and DES for the rest.  They are able to do this
 -	because the DES libraries also contain MD5.  Unfortunately, the
 -	reverse is not true, so the MD5 libraries cannot authenticate
 -	passwords that were encrypted with DES.</para>
 -  
 -      <para>Identifying which library is being used by the programs on
 -	your system is easy as well. Any program that uses crypt is linked
 -	against libcrypt, which for each type of library is a symbolic link
 -	to the appropriate implementation. For example, on a system using
 -	the DES versions:</para>
 -
 -      <screen>&prompt.user; <userinput>ls -l /usr/lib/libcrypt*</userinput>
 -lrwxr-xr-x  1 root  wheel  13 Mar 19 06:56 libcrypt.a -&gt; libdescrypt.a
 -lrwxr-xr-x  1 root  wheel  18 Mar 19 06:56 libcrypt.so.2.0 -&gt; libdescrypt.so.2.0
 -lrwxr-xr-x  1 root  wheel  15 Mar 19 06:56 libcrypt_p.a -&gt; libdescrypt_p.a</screen>
  
 -      <para>On a system using the MD5-based libraries, the same links will
 -	be present, but the target will be <filename>libscrypt</filename>
 -	rather than <filename>libdescrypt</filename>.</para>
 +      <para>Which password format will be used for new passwords is
 +	controlled by the <quote>passwd_format</quote> login capability in
 +        <filename>/etc/login.conf</filename>, which takes values of
 +        <quote>des</quote> or <quote>md5</quote> or <quote>blf</quote>.
 +	See the &man.login.conf.5; manual page for more information about
 +	login capabilities.</para>
  
 -      <para>If you have installed the DES-capable crypt library
 -      <filename>libdescrypt</filename> (e.g. by installing the
 -      "crypto" distribution), then which password format will be used
 -      for new passwords is controlled by the
 -      <quote>passwd_format</quote> login capability in
 -      <filename>/etc/login.conf</filename>, which takes values of
 -      either <quote>des</quote> or <quote>md5</quote>.  See the
 -      &man.login.conf.5; manual page for more information about login
 -      capabilities.</para>
      </sect2>
    </sect1>
  
 
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