{"id":7758,"date":"2017-05-25T06:30:12","date_gmt":"2017-05-25T14:30:12","guid":{"rendered":"http:\/\/www.palada.net\/index.php\/2017\/05\/25\/news-1543\/"},"modified":"2017-05-25T06:30:12","modified_gmt":"2017-05-25T14:30:12","slug":"news-1543","status":"publish","type":"post","link":"http:\/\/www.palada.net\/index.php\/2017\/05\/25\/news-1543\/","title":{"rendered":"IDG Contributor Network: The complexity of password complexity"},"content":{"rendered":"<p><img decoding=\"async\" src=\"http:\/\/zapt0.staticworld.net\/images\/article\/2016\/08\/passwords-100678100-primary.idge.jpg\"\/><\/p>\n<p><strong>Credit to Author: Sandra Henry-Stocker| Date: Thu, 25 May 2017 05:47:00 -0700<\/strong><\/p>\n<p>Deploying password quality checking on your Debian-base Linux servers can help to ensure that your users assign reasonable passwords on their accounts, but the settings themselves can be a bit misleading. For example, setting a minimum password length of 12 characters does not mean that your users&#8217; passwords will all have twelve or more characters. Let&#8217;s stroll down Complexity Boulevard and see how the settings work and examine some settings worth considering.<\/p>\n<p>First, if you haven&#8217;t done this already, install the password quality checking library with this command:<\/p>\n<p>The files that contain most of the settings we&#8217;re going to look at will be:<\/p>\n<p>Here&#8217;s how it works. You can set a minimum password length, but it doesn&#8217;t work exactly like you might think. People can set themselves up with shorter passwords if they incorporate some additional complexity and get credit for doing so.<\/p>\n<p>Complexity settings allow you to do quite a number of things in addition to requiring a minimum password length. You can require:<\/p>\n<p>The settings include:<\/p>\n<p>Implementing these settings in your common-password file might look like this:<\/p>\n<p>The idea of &#8220;credits&#8221; is very interesting. Basically, you&#8217;re getting credit for complexity. A shorter password might be acceptable if it&#8217;s more complex in other ways &#8212; like the mix of characters \u2013 than length.<\/p>\n<p>As an example, a password like &#8220;hijlmqrazp&#8221; might pass a minlen=10 test. If dcredit is set to 2, on the other hand, the password &#8220;hijlmq99&#8221; would also pass. Why? Because we&#8217;d get 2 credits for the digits. So, 8 characters plus 2 credits is valued as highly as 10 characters. If dcredit was set to 1, you would need an additional character. However, we could get credits for uppercase, lowercase, and non-alphanumeric characters (like punctuation characters).<\/p>\n<p>Note, however, that you can only get credit for so many of the different characters. Maybe you will get credit for only one digit or two uppercase characters. Maybe you don&#8217;t get any credit for lowercase characters. It all depends on your settings.<\/p>\n<p>One other setting which comes into play is the minclass setting. This setting determines how many different classes of characters \u2013 must be used for a password to be acceptable. If minclass is set to 2, a password containing all lowercase, all uppercase, all digits, or all other characters wouldn&#8217;t work. If set to 2, minclass would require you to use characters from two classes \u2013 like uppercase and lowercase, or lowercase and digits.<\/p>\n<p>With minclass set to 4, passwords would have to include all four types of characters \u2013 like \u201chowzit2B?\u201d and, if we get credit for uppercase, digits, or other characters, we&#8217;d be OK even with the minlen set to 12.<\/p>\n<p>You can also put a cap on the number of characters of any particular class. Set the maxclassrepeat setting to 4 and passwords cannot contain more than 4 lowercase, uppercase, digits, or other characters in succession.<\/p>\n<p>Setting one of the lcredit, ucredit, dcredit, or ocredit settings to a negative number means that you MUST have some of that type of character. Setting dcredit to -1, for example, would mean that you have to include at least one digit for a password to be accepted.<\/p>\n<p>PAM&#8217;s password quality checking also includes a number of other checks that help ensure that passwords are fairly secure. It checks to see if a password is a palindrome (e.g., \u201cracecar\u201d), whether a new password is the same as the old password but with a change of case only, if the old and new passwords are too similar or rotations of each other, and whether a password contains the user&#8217;s name. It&#8217;s getting to the point that it might actually be difficult to assign oneself a really bad password.<\/p>\n<p><strong>This article is published as part of the IDG Contributor Network. <a href=\"\/contributor-network\/signup.html\">Want to Join?<\/a><\/strong><\/p>\n<p><a href=\"http:\/\/www.computerworld.com\/article\/3198444\/linux\/the-complexity-of-password-complexity.html#tk.rss_security\" target=\"bwo\" >http:\/\/www.computerworld.com\/category\/security\/index.rss<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p><img decoding=\"async\" src=\"http:\/\/zapt0.staticworld.net\/images\/article\/2016\/08\/passwords-100678100-primary.idge.jpg\"\/><\/p>\n<p><strong>Credit to Author: Sandra Henry-Stocker| Date: Thu, 25 May 2017 05:47:00 -0700<\/strong><\/p>\n<article>\n<section class=\"page\">\n<p>Deploying password quality checking on your Debian-base Linux servers can help to ensure that your users assign reasonable passwords on their accounts, but the settings themselves can be a bit misleading. For example, setting a minimum password length of 12 characters does not mean that your users&#8217; passwords will all have twelve or more characters. Let&#8217;s stroll down Complexity Boulevard and see how the settings work and examine some settings worth considering.<\/p>\n<p>First, if you haven&#8217;t done this already, install the password quality checking library with this command:<\/p>\n<pre>apt-get -y install libpam-pwquality <\/pre>\n<p>The files that contain most of the settings we&#8217;re going to look at will be:<\/p>\n<p class=\"jumpTag\"><a href=\"\/article\/3198444\/linux\/the-complexity-of-password-complexity.html#jump\">To read this article in full or to leave a comment, please click here<\/a><\/p>\n<\/section>\n<\/article>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[11062,10643],"tags":[10496,714],"class_list":["post-7758","post","type-post","status-publish","format-standard","hentry","category-computerworld","category-independent","tag-linux","tag-security"],"_links":{"self":[{"href":"http:\/\/www.palada.net\/index.php\/wp-json\/wp\/v2\/posts\/7758","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.palada.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.palada.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.palada.net\/index.php\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"http:\/\/www.palada.net\/index.php\/wp-json\/wp\/v2\/comments?post=7758"}],"version-history":[{"count":0,"href":"http:\/\/www.palada.net\/index.php\/wp-json\/wp\/v2\/posts\/7758\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.palada.net\/index.php\/wp-json\/wp\/v2\/media?parent=7758"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.palada.net\/index.php\/wp-json\/wp\/v2\/categories?post=7758"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.palada.net\/index.php\/wp-json\/wp\/v2\/tags?post=7758"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}