WongTek Blog

Tag: Ubuntu

  • Using Google Authenticator on Ubuntu for SSH

    Run:

    $ apt-get update
    $ apt-get -yy install gcc mercurial libpam0g-dev git
    $ git clone https://code.google.com/p/google-authenticator/
    $ cd google-authenticator/libpam
    $ make install

    Edit /etc/ssh/sshd_config file and change the ChallengeResponseAuthentication from no to yes

    edit /etc/pam.d/common-auth so it looks like

    # here are the per-package modules (the "Primary" block)
    auth required pam_google_authenticator.so
    auth [success=1 default=ignore] pam_unix.so nullok_secure
    # here's the fallback if no module succeeds

    Run google-authenticator as the user you want to use two factor authentication on.
    Paste the generated URL into your browser and a QRCode will be generated.
    Scan the QR code with the Google Authenticator app on your iPhone.
    Reboot the server and test.

  • AirPrint and Ubuntu

    This is what i did for my Canon MX850 to get AirPrint working on my Ubuntu system.

    1. Have a Standard install of Ubuntu Desktop.
    2. Go into the CUPS interface and make sure “Share published printers connected to this system” is enabled on the server settings.

    3. Install avahi-daemon and make sure it is running.

    4. Install avahi-discover and run it from a terminal. Click the printer you wish to duplicate. You should get something like:

    [code]
    Service Type: _ipp._tcp
    Service Name: Canon MX850 @ Saturn
    Domain Name: local
    Interface: eth0 IPv4
    Address: Saturn.local/10.0.0.4:30466
    TXT Binary = T
    TXT adminurl = http://Saturn:631/printers/Canon-MX850
    TXT Duplex = T
    TXT Copies = F
    TXT Collate = F
    TXT Sort = F
    TXT priority = 0
    TXT Fax = F
    TXT rp = printers/Canon-MX850
    TXT ty = Canon PIXMA iP5300 – CUPS+Gutenprint v5.2.6 Simplified
    TXT Punch = F
    TXT note = Saturn
    TXT printer-state = 3
    TXT txtvers = 1
    TXT Transparent = T
    TXT product = (Canon PIXMA iP5300)
    TXT qtotal = 1
    TXT Bind = F
    TXT printer-type = 0xB01E
    TXT Scan = F
    TXT Color = T
    TXT pdl = application/octet-stream,application/pdf,application/postscript,image/jpeg,image/png
    TXT Staple = F
    [/code]

    5. Create file name /etc/avahi/services/mx850.service.

    6. Create an XML file similar to the example below, using the data above as the values.

    [code]

    < ?xml version="1.0" standalone=’no’?>
    < !DOCTYPE service-group SYSTEM "avahi-service.dtd">
    <service -group>
    <name replace-wildcards="yes">AirPrint MX850 @ %h</name>
    </service><service>
    <type>_ipp._tcp</type>
    <subtype>_universal._sub._ipp._tcp</subtype>
    <port>631</port>
    <txt -record>txtvers=1</txt>
    <txt -record>qtotal=1</txt>
    <txt -record>rp=printers/Canon-MX850</txt>
    <txt -record>ty=Canon PIXMA iP5300 – CUPS+Gutenprint v5.2.6 Simplified</txt>
    <txt -record>note=Saturn</txt>
    <txt -record>product=(Canon PIXMA iP5300)</txt>
    <txt -record>printer-state=3</txt>
    <txt -record>printer-type=0xB01E</txt>
    <txt -record>Transparent=T</txt>
    <txt -record>Binary=T</txt>
    <txt -record>Duplex=T</txt>
    <txt -record>Copies=F</txt>
    <txt -record>pdl=application/octet-stream,application/pdf,application/postscript,image/jpeg,image/png</txt>
    <txt -record>URF=none</txt>
    </service>

    [/code]

    7. Save the file. avahi-daemon should notice the new file and load it without a needed restart.

    8. Add the following to /etc/cups/cupsd.conf near the top

    [code]
    ServerAlias *
    Port 631
    [/code]

    9. Restart CUPS “/etc/init.d/cups restart”

    10. On your iPhone/iPad, go into Safari, print, and search for printers. Your new printer should be in there.

    —————————-

    Update: as of June 28, AirPrint is built-in on Ubuntu 11.10.
    1. On your computer start system-config-printer via System ->
    Administration -> Printing (GNOME Classic) or via Turn-off-button at the
    upper right -> System Settings -> Hardware -> Printing (Unity Natty) or
    via the command line (all systems including Unity Oneiric).

    2. In system-config-printer choose Server -> Settings and activate
    “Published shared printers connected to this system”. Click OK and then
    right-click on the icon of your print queue and choose Properties in the
    pop-up menu. In the Policies section of the dialog make sure that
    “Shared” is activated.

    3. Make sure your mobile device is accessing your local network using
    WLAN and then open an application with printing functionality on it
    (like for example the browser or the photo viewer). Print something. The
    print dialog should show your print queue and allow some basic settings.
    Note that the Description/Info field and not the name of the queue is shown.

    4. Check whether you get a correct printout.