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   5   <title>Petter Reinholdtsen: entries from May 2010</title>
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  14        <a href="http://people.skolelinux.org/pere/blog/">Petter Reinholdtsen</a>
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  17
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  19
  20  <p>Entries from May 2010.</p>
  21
  22
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  24  <div class="title">
  25  <a href="http://people.skolelinux.org/pere/blog/Forcing_new_users_to_change_their_password_on_first_login.html">Forcing new users to change their password on first login</a>
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  27  <div class="date">
  28   2010-05-02 13:47
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  32
  33 <p>One interesting feature in Active Directory, is the ability to
  34 create a new user with an expired password, and thus force the user to
  35 change the password on the first login attempt.</p>
  36
  37 <p>I'm not quite sure how to do that with the LDAP setup in Debian
  38 Edu, but did some initial testing with a local account.  The account
  39 and password aging information is available in /etc/shadow, but
  40 unfortunately, it is not possible to specify an expiration time for
  41 passwords, only a maximum age for passwords.</p>
  42
  43 <p>A freshly created account (using adduser test) will have these
  44 settings in /etc/shadow:</p>
  45
  46 <blockquote><pre>
  47 root@tjener:~# chage -l test
  48 Last password change                                    : May 02, 2010
  49 Password expires                                        : never
  50 Password inactive                                       : never
  51 Account expires                                         : never
  52 Minimum number of days between password change          : 0
  53 Maximum number of days between password change          : 99999
  54 Number of days of warning before password expires       : 7
  55 root@tjener:~#
  56 </pre></blockquote>
  57
  58 <p>The only way I could come up with to create a user with an expired
  59 account, is to change the date of the last password change to the
  60 lowest value possible (January 1th 1970), and the maximum password age
  61 to the difference in days between that date and today.  To make it
  62 simple, I went for 30 years (30 * 365 = 10950) and January 2th (to
  63 avoid testing if 0 is a valid value).</p>
  64
  65 <p>After using these commands to set it up, it seem to work as
  66 intended:</p>
  67
  68 <blockquote><pre>
  69 root@tjener:~# chage -d 1 test; chage -M 10950 test
  70 root@tjener:~# chage -l test
  71 Last password change                                    : Jan 02, 1970
  72 Password expires                                        : never
  73 Password inactive                                       : never
  74 Account expires                                         : never
  75 Minimum number of days between password change          : 0
  76 Maximum number of days between password change          : 10950
  77 Number of days of warning before password expires       : 7
  78 root@tjener:~#
  79 </pre></blockquote>
  80
  81 <p>So far I have tested this with ssh and console, and kdm (in
  82 Squeeze) login, and all ask for a new password before login in the
  83 user (with ssh, I was thrown out and had to log in again).</p>
  84
  85 <p>Perhaps we should set up something similar for Debian Edu, to make
  86 sure only the user itself have the account password?</p>
  87
  88 <p>If you want to comment on or help out with implementing this for
  89 Debian Edu, please contact us on debian-edu@lists.debian.org.</p>
  90
  91 <p>Update 2010-05-02 17:20: Paul Tötterman tells me on IRC that the
  92 shadow(8) page in Debian/testing now state that setting the date of
  93 last password change to zero (0) will force the password to be changed
  94 on the first login.  This was not mentioned in the manual in Lenny, so
  95 I did not notice this in my initial testing.  I have tested it on
  96 Squeeze, and '<tt>chage -d 0 username</tt>' do work there.  I have not
  97 tested it on Lenny yet.</p>
  98
  99 <p>Update 2010-05-02-19:05: Jim Paris tells me via email that an
 100 equivalent command to expire a password is '<tt>passwd -e
 101 username</tt>', which insert zero into the date of the last password
 102 change.</p>
 103
 104  </div>
 105  <div class="tags">
 106
 107
 108
 109   Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>.
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 112 </div>
 113  <div class="padding"></div>
 114
 115  <p style="text-align: right;"><a href="05.rss"><img src="http://people.skolelinux.org/pere/blog/xml.gif" alt="RSS Feed" width="36" height="14"></a></p>
 116
 117
 118
 119 <div id="sidebar">
 120
 121 <h2>Archive</h2>
 122 <ul>
 123
 124 <li>2010
 125 <ul>
 126
 127 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/01/">January (2)</a></li>
 128
 129 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/02/">February (1)</a></li>
 130
 131 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/03/">March (3)</a></li>
 132
 133 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/04/">April (3)</a></li>
 134
 135 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/05/">May (1)</a></li>
 136
 137 </ul></li>
 138
 139 <li>2009
 140 <ul>
 141
 142 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/01/">January (8)</a></li>
 143
 144 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/02/">February (8)</a></li>
 145
 146 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/03/">March (12)</a></li>
 147
 148 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/04/">April (10)</a></li>
 149
 150 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/05/">May (9)</a></li>
 151
 152 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/06/">June (3)</a></li>
 153
 154 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/07/">July (4)</a></li>
 155
 156 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/08/">August (3)</a></li>
 157
 158 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/09/">September (1)</a></li>
 159
 160 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/10/">October (2)</a></li>
 161
 162 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/11/">November (3)</a></li>
 163
 164 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/12/">December (3)</a></li>
 165
 166 </ul></li>
 167
 168 <li>2008
 169 <ul>
 170
 171 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/11/">November (5)</a></li>
 172
 173 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/12/">December (7)</a></li>
 174
 175 </ul></li>
 176
 177 </ul>
 178
 179
 180
 181 <h2>Tags</h2>
 182 <ul>
 183
 184  <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (11)</a></li>
 185
 186  <li><a href="http://people.skolelinux.org/pere/blog/tags/amiga">amiga (1)</a></li>
 187
 188  <li><a href="http://people.skolelinux.org/pere/blog/tags/aros">aros (1)</a></li>
 189
 190  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (14)</a></li>
 191
 192  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (15)</a></li>
 193
 194  <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (24)</a></li>
 195
 196  <li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (1)</a></li>
 197
 198  <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (6)</a></li>
 199
 200  <li><a href="http://people.skolelinux.org/pere/blog/tags/kart">kart (2)</a></li>
 201
 202  <li><a href="http://people.skolelinux.org/pere/blog/tags/lenker">lenker (1)</a></li>
 203
 204  <li><a href="http://people.skolelinux.org/pere/blog/tags/ltsp">ltsp (1)</a></li>
 205
 206  <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (5)</a></li>
 207
 208  <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (64)</a></li>
 209
 210  <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (71)</a></li>
 211
 212  <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (12)</a></li>
 213
 214  <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (11)</a></li>
 215
 216  <li><a href="http://people.skolelinux.org/pere/blog/tags/reprap">reprap (10)</a></li>
 217
 218  <li><a href="http://people.skolelinux.org/pere/blog/tags/rss">rss (1)</a></li>
 219
 220  <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (7)</a></li>
 221
 222  <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (11)</a></li>
 223
 224  <li><a href="http://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (1)</a></li>
 225
 226  <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (10)</a></li>
 227
 228  <li><a href="http://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (1)</a></li>
 229
 230  <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (6)</a></li>
 231
 232 </ul>
 233
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