8 ways to generate random password in Linux ====== Learn 8 different ways to generate random password in Linux using Linux native commands or third party utilities. ![][1] In this article, we will walk you through various different ways to generate random password in Linux terminal. Few of them are using native Linux commands and others are using third party tools or utilities which can easily be installed on Linux machine. Here we are looking at native commands like `openssl`, [dd][2], `md5sum`, `tr`, `urandom` and third party tools like mkpasswd, randpw, pwgen, spw, gpg, xkcdpass, diceware, revelation, keepaasx, passwordmaker. These are actually ways to get some random alphanumeric string which can be utilized as password. Random passwords can be used for new users so that there will be uniqueness no matter how large your user base is. Without any further delay lets jump into those 15 different ways to generate random password in Linux. ##### Generate password using mkpasswd utility `mkpasswd` comes with install of `expect` package on RHEL based systems. On Debian based systems `mkpasswd` comes with package `whois`. Trying to install `mkpasswd` package will results in error - No package mkpasswd available. on RHEL system and E: Unable to locate package mkpasswd in Debian based. So install their parent packages as mentioned above and you are good to go. Run `mkpasswd` to get passwords ``` root@kerneltalks# mkpasswd << on RHEL zt*hGW65c root@kerneltalks# mkpas ``` Command behaves differently on different systems so work accordingly. There are many switches which can be used to control length etc parameters. You can explore them from man pages. ##### Generate password using openssl Openssl comes in build with almost all the Linux distributions. We can use its random function to get alphanumeric string generated which can be used as password. ``` root@kerneltalks # openssl rand -base64 10 nU9LlHO5nsuUvw== ``` Here, we are using `base64` encoding with random function and last digit for argument to `base64` encoding. ##### Generate password using urandom Device file `/dev/urandom` is another source of getting random characters. We are using `tr` function and trimming output to get random string to use as password. ``` root@kerneltalks # strings /dev/urandom |tr -dc A-Za-z0-9 | head -c20; echo UiXtr0NAOSIkqtjK4c0X ``` ##### dd command to generate password We can even use /dev/urandom device along with [dd command ][2]to get string of random characters. ``` oot@kerneltalks# dd if=/dev/urandom bs=1 count=15|base64 -w 0 15+0 records in 15+0 records out 15 bytes (15 B) copied, 5.5484e-05 s, 270 kB/s QMsbe2XbrqAc2NmXp8D0 ``` We need to pass output through `base64` encoding to make it human readable. You can play with count value to get desired length. For much cleaner output, redirect std2 to `/dev/null`. Clean command will be - ``` oot@kerneltalks # dd if=/dev/urandom bs=1 count=15 2>/dev/null|base64 -w 0 F8c3a4joS+a3BdPN9C++ ``` ##### Using md5sum to generate password Another way to get array of random characters which can be used as password is to calculate MD5 checksum! s you know checksum value is indeed looks like random characters grouped together we can use it as password. Make sure you use source as something variable so that you get different checksum every time you run command. For example `date` ! [date command][3] always yields changing output. ``` root@kerneltalks # date |md5sum 4d8ce5c42073c7e9ca4aeffd3d157102 - ``` Here we passed `date` command output to `md5sum` and get the checksum hash! You can use [cut command][4] to get desired length of output. ##### Generate password using pwgen `pwgen` package comes with [repositories like EPEL][5]. `pwgen` is more focused on generating passwords which are pronounceable but not a dictionary word or not in plain English. You may not find it in standard distribution repo. Install the package and run `pwgen` command. Boom ! ``` root@kerneltalks # pwgen thu8Iox7 ahDeeQu8 Eexoh0ai oD8oozie ooPaeD9t meeNeiW2 Eip6ieph Ooh1tiet cootad7O Gohci0vo wah9Thoh Ohh3Ziur Ao1thoma ojoo6aeW Oochai4v ialaiLo5 aic2OaDa iexieQu8 Aesoh4Ie Eixou9ph ShiKoh0i uThohth7 taaN3fuu Iege0aeZ cah3zaiW Eephei0m AhTh8guo xah1Shoo uh8Iengo aifeev4E zoo4ohHa fieDei6c aorieP7k ahna9AKe uveeX7Hi Ohji5pho AigheV7u Akee9fae aeWeiW4a tiex8Oht ``` You will be presented with list of passwords at your terminal! What else you want? Ok. You still want to explore, `pwgen` comes with many custom options which can be referred for man page. ##### Generate password using gpg tool GPG is a OpenPGP encryption and signing tool. Mostly gpg tool comes pre-installed (at least it is on my RHEL7). But if not you can look for `gpg` or `gpg2` package and [install][6] it. Use below command to generate password from gpg tool. ``` root@kerneltalks # gpg --gen-random --armor 1 12 mL8i+PKZ3IuN6a7a ``` Here we are passing generate random byte sequence switch (`--gen-random`) of quality 1 (first argument) with count of 12 (second argument). Switch `--armor` ensures output is `base64` encoded. ##### Generate password using xkcdpass Famous geek humor website [xkcd][7], published a very interesting post about memorable but still complex passwords. You can view it [here][8]. So `xkcdpass` tool took inspiration from this post and did its work! Its a python package and available on python's official website [here][9] All installation and usage instructions are mentioned on that page. Here is install steps and outputs from my test RHEL server for your reference. ``` root@kerneltalks # wget https://pypi.python.org/packages/b4/d7/3253bd2964390e034cf0bba227db96d94de361454530dc056d8c1c096abc/xkcdpass-1.14.3.tar.gz#md5=5f15d52f1d36207b07391f7a25c7965f --2018-01-23 19:09:17-- https://pypi.python.org/packages/b4/d7/3253bd2964390e034cf0bba227db96d94de361454530dc056d8c1c096abc/xkcdpass-1.14.3.tar.gz Resolving pypi.python.org (pypi.python.org)... 151.101.32.223, 2a04:4e42:8::223 Connecting to pypi.python.org (pypi.python.org)|151.101.32.223|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 871848 (851K) [binary/octet-stream] Saving to: ‘xkcdpass-1.14.3.tar.gz’ 100%[==============================================================================================================================>] 871,848 --.-K/s in 0.01s 2018-01-23 19:09:17 (63.9 MB/s) - ‘xkcdpass-1.14.3.tar.gz’ saved [871848/871848] root@kerneltalks # tar -xvf xkcdpass-1.14.3.tar.gz xkcdpass-1.14.3/ xkcdpass-1.14.3/examples/ xkcdpass-1.14.3/examples/example_import.py xkcdpass-1.14.3/examples/example_json.py xkcdpass-1.14.3/examples/example_postprocess.py xkcdpass-1.14.3/LICENSE.BSD xkcdpass-1.14.3/MANIFEST.in xkcdpass-1.14.3/PKG-INFO xkcdpass-1.14.3/README.rst xkcdpass-1.14.3/setup.cfg xkcdpass-1.14.3/setup.py xkcdpass-1.14.3/tests/ xkcdpass-1.14.3/tests/test_list.txt xkcdpass-1.14.3/tests/test_xkcdpass.py xkcdpass-1.14.3/tests/__init__.py xkcdpass-1.14.3/xkcdpass/ xkcdpass-1.14.3/xkcdpass/static/ xkcdpass-1.14.3/xkcdpass/static/eff-long xkcdpass-1.14.3/xkcdpass/static/eff-short xkcdpass-1.14.3/xkcdpass/static/eff-special xkcdpass-1.14.3/xkcdpass/static/fin-kotus xkcdpass-1.14.3/xkcdpass/static/ita-wiki xkcdpass-1.14.3/xkcdpass/static/legacy xkcdpass-1.14.3/xkcdpass/static/spa-mich xkcdpass-1.14.3/xkcdpass/xkcd_password.py xkcdpass-1.14.3/xkcdpass/__init__.py xkcdpass-1.14.3/xkcdpass.1 xkcdpass-1.14.3/xkcdpass.egg-info/ xkcdpass-1.14.3/xkcdpass.egg-info/dependency_links.txt xkcdpass-1.14.3/xkcdpass.egg-info/entry_points.txt xkcdpass-1.14.3/xkcdpass.egg-info/not-zip-safe xkcdpass-1.14.3/xkcdpass.egg-info/PKG-INFO xkcdpass-1.14.3/xkcdpass.egg-info/SOURCES.txt xkcdpass-1.14.3/xkcdpass.egg-info/top_level.txt root@kerneltalks # cd xkcdpass-1.14.3 root@kerneltalks # python setup.py install running install running bdist_egg running egg_info writing xkcdpass.egg-info/PKG-INFO writing top-level names to xkcdpass.egg-info/top_level.txt writing dependency_links to xkcdpass.egg-info/dependency_links.txt writing entry points to xkcdpass.egg-info/entry_points.txt reading manifest file 'xkcdpass.egg-info/SOURCES.txt' reading manifest template 'MANIFEST.in' writing manifest file 'xkcdpass.egg-info/SOURCES.txt' installing library code to build/bdist.linux-x86_64/egg running install_lib running build_py creating build creating build/lib creating build/lib/xkcdpass copying xkcdpass/xkcd_password.py -> build/lib/xkcdpass copying xkcdpass/__init__.py -> build/lib/xkcdpass creating build/lib/xkcdpass/static copying xkcdpass/static/eff-long -> build/lib/xkcdpass/static copying xkcdpass/static/eff-short -> build/lib/xkcdpass/static copying xkcdpass/static/eff-special -> build/lib/xkcdpass/static copying xkcdpass/static/fin-kotus -> build/lib/xkcdpass/static copying xkcdpass/static/ita-wiki -> build/lib/xkcdpass/static copying xkcdpass/static/legacy -> build/lib/xkcdpass/static copying xkcdpass/static/spa-mich -> build/lib/xkcdpass/static creating build/bdist.linux-x86_64 creating build/bdist.linux-x86_64/egg creating build/bdist.linux-x86_64/egg/xkcdpass copying build/lib/xkcdpass/xkcd_password.py -> build/bdist.linux-x86_64/egg/xkcdpass copying build/lib/xkcdpass/__init__.py -> build/bdist.linux-x86_64/egg/xkcdpass creating build/bdist.linux-x86_64/egg/xkcdpass/static copying build/lib/xkcdpass/static/eff-long -> build/bdist.linux-x86_64/egg/xkcdpass/static copying build/lib/xkcdpass/static/eff-short -> build/bdist.linux-x86_64/egg/xkcdpass/static copying build/lib/xkcdpass/static/eff-special -> build/bdist.linux-x86_64/egg/xkcdpass/static copying build/lib/xkcdpass/static/fin-kotus -> build/bdist.linux-x86_64/egg/xkcdpass/static copying build/lib/xkcdpass/static/ita-wiki -> build/bdist.linux-x86_64/egg/xkcdpass/static copying build/lib/xkcdpass/static/legacy -> build/bdist.linux-x86_64/egg/xkcdpass/static copying build/lib/xkcdpass/static/spa-mich -> build/bdist.linux-x86_64/egg/xkcdpass/static byte-compiling build/bdist.linux-x86_64/egg/xkcdpass/xkcd_password.py to xkcd_password.pyc byte-compiling build/bdist.linux-x86_64/egg/xkcdpass/__init__.py to __init__.pyc creating build/bdist.linux-x86_64/egg/EGG-INFO copying xkcdpass.egg-info/PKG-INFO -> build/bdist.linux-x86_64/egg/EGG-INFO copying xkcdpass.egg-info/SOURCES.txt -> build/bdist.linux-x86_64/egg/EGG-INFO copying xkcdpass.egg-info/dependency_links.txt -> build/bdist.linux-x86_64/egg/EGG-INFO copying xkcdpass.egg-info/entry_points.txt -> build/bdist.linux-x86_64/egg/EGG-INFO copying xkcdpass.egg-info/not-zip-safe -> build/bdist.linux-x86_64/egg/EGG-INFO copying xkcdpass.egg-info/top_level.txt -> build/bdist.linux-x86_64/egg/EGG-INFO creating dist creating 'dist/xkcdpass-1.14.3-py2.7.egg' and adding 'build/bdist.linux-x86_64/egg' to it removing 'build/bdist.linux-x86_64/egg' (and everything under it) Processing xkcdpass-1.14.3-py2.7.egg creating /usr/lib/python2.7/site-packages/xkcdpass-1.14.3-py2.7.egg Extracting xkcdpass-1.14.3-py2.7.egg to /usr/lib/python2.7/site-packages Adding xkcdpass 1.14.3 to easy-install.pth file Installing xkcdpass script to /usr/bin Installed /usr/lib/python2.7/site-packages/xkcdpass-1.14.3-py2.7.egg Processing dependencies for xkcdpass==1.14.3 Finished processing dependencies for xkcdpass==1.14.3 ``` Now running xkcdpass command will give you random set of dictionary words like below - ``` root@kerneltalks # xkcdpass broadside unpadded osmosis statistic cosmetics lugged ``` You can use these words as input to other commands like `md5sum` to get random password (like below) or you can even use Nth letter of each words to form your password! ``` oot@kerneltalks # xkcdpass |md5sum 45f2ec9b3ca980c7afbd100268c74819 - root@kerneltalks # xkcdpass |md5sum ad79546e8350744845c001d8836f2ff2 - ``` Or even you can use all those words together as such a long password which is easy to remember for a user and very hard to crack using computer program. There are tools like [Diceware][10], [KeePassX][11], [Revelation][12], [PasswordMaker][13] for Linux which can be considered for making strong random passwords. -------------------------------------------------------------------------------- via: https://kerneltalks.com/tips-tricks/8-ways-to-generate-random-password-in-linux/ 作者：[kerneltalks][a] 译者：[译者ID](https://github.com/译者ID) 校对：[校对者ID](https://github.com/校对者ID) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 [a]:https://kerneltalks.com [1]:https://a1.kerneltalks.com/wp-content/uploads/2018/01/different-ways-to-generate-password-in-linux.png [2]:https://kerneltalks.com/commands/learn-dd-command-with-examples/ [3]:https://kerneltalks.com/commands/date-time-management-using-timedatectl-command/ [4]:https://kerneltalks.com/linux/cut-command-examples/ [5]:https://kerneltalks.com/package/how-to-install-epel-repository/ [6]:https://kerneltalks.com/tools/package-installation-linux-yum-apt/ [7]:https://xkcd.com/ [8]:https://xkcd.com/936/ [9]:https://pypi.python.org/pypi/xkcdpass/ [10]:http://world.std.com/~reinhold/diceware.html [11]:https://www.keepassx.org/ [12]:https://packages.debian.org/sid/gnome/revelation [13]:https://passwordmaker.org/