Tutorial_ How to Use Dropbox Behind a Corporate Proxy Server Using CNTLM _ I Code and Code
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21-11-13 Tutorial: How to use Dropbox behind a corporate proxy server using CNTLM | I code and code www.icodeandcode.com/2012/02/tutorial-how-to-use-dropbox-behind.html 1/12 20th February 2012 So you want to use dropbox behind a corporate proxy/firewall. You've probably faile d due to connection issues, caused by the advanced authentication method your co rporate proxy requires. In this guide we will create a local authentication proxy using CNTLM, and pass all d ropbox traffic through it instead of your normal proxy. This isn't just a dropbox proxy, in fact it has very little to do with dropbox. It's a perfe ct solution for any app that needs an authentication proxy (meaning it can't authenti cate through your normal proxy). [http://2.bp.blogspot.com/-mN59TN0lhcE/T0EpepiJItI/AAAAAAAAAVo/iKYXBgMsuVM/s1 600/dropbox1.png] Does this look familiar? Then this guide is for you. Don't worry, it's easier than it sounds. Step 1: Install CNTLM Get it from the CNTLM homepage [http://cntlm.sourceforge.net/] . Installation is as sim ple as running the installer. There are no complicated configurations. Tutorial: How to use Dropbox behin d a corporate proxy server using C NTLM
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Transcript of Tutorial_ How to Use Dropbox Behind a Corporate Proxy Server Using CNTLM _ I Code and Code
21-11-13 Tutorial: How to use Dropbox behind a corporate proxy server using CNTLM | I code and code
www.icodeandcode.com/2012/02/tutorial-how-to-use-dropbox-behind.html 1/12
20th February 2012
So you want to use dropbox behind a corporate proxy/firewall. You've probably faile
d due to connection issues, caused by the advanced authentication method your co
rporate proxy requires.
In this guide we will create a local authentication proxy using CNTLM, and pass all d
ropbox traffic through it instead of your normal proxy.
This isn't just a dropbox proxy, in fact it has very little to do with dropbox. It's a perfe
ct solution for any app that needs an authentication proxy (meaning it can't authenti
cate through your normal proxy).
[http://2.bp.blogspot.com/-mN59TN0lhcE/T0EpepiJItI/AAAAAAAAAVo/iKYXBgMsuVM/s1
600/dropbox1.png]Does this look familiar? Then this guide is for you.
Don't worry, it's easier than it sounds.
Step 1: Install CNTLMGet it from the CNTLM homepage [http://cntlm.sourceforge.net/] . Installation is as sim
ple as running the installer. There are no complicated configurations.
Tutorial: How to use Dropbox behind a corporate proxy server using C
NTLM
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Step 2: Configure CNTLMOpen up cntlm.ini in a text editor. Notepad will do just fine. You'll need to edit the foll
owing sections:
Username [Your username. It's the one you use to log on to your computer at work]
Domain [Your domain. If you don't know it look in Control Panel -->System and Security
-->System Configuration]
Password [Your password]
Proxy [Your corporate proxy address. Find this out from your browser settings or a fe
llow worker or even an IT person. You can enter more than one if your company employs a
few proxies]
Listen [Port number. Default is 3128 and there is no reason to change it unless you ha
ppen to have another server listening on that port.]
If you're worried about leaving your password as plain text in the config file, you pro
bably should. You can store an encrypted password instead [http://icodeandcode.blog
spot.com/2012/10/advanced-cntlm-secure-configuration.html] .
Step 3: Determine the authentication method your corporate proxy
usesOpen up a command line window (just run cmd) and run
cntlm -M http://google.com
(The capital M is important!)
This will run CNTLM in diagnostic mode and test the connection against google.com
, then provide us the information we need to continue. Your output should look simil
ar to this:
Config profile 1/4... OK (HTTP code: 301)
----------------------------[ Profile 0]------
Auth NTLMv2
PassNTLMv2 [ a pass phrase ]
------------------------------------------------
What we need to note is the authentication method. In this case, it's NTLMv2.
Step 4: Final CNTLM ConfigurationOpen up cntlm.ini in a text editor again. You'll need to edit the Auth section:
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Auth [The authentication method we established in step 2. In this example it's NTLMv2]
Step 4: Configure Dropbox
[http://1.bp.blogs
pot.com/-lZiq7gHjPQA/T0EphxL5-eI/AAAAAAAAAVw/W-84pg0B19g/s1600/dropbox2.png]Make sure the port number is the same is the Listen paramter you configured in cntlm.ini in step 3
All done! Let me know in the comments if you have any questions.
FAQ
I can't install CNTLM, what do I do?
Maybe because you're getting this error: "You must be logged in as an administrato
r when installing this program", maybe because you don't want to install stuff on so
meone else's computer. You can download the portable version of CNTLM [http://ico
deandcode.blogspot.com/2012/10/tutorial-cntlm-portable.html] . It requires no installation.
You'll just have to run it manually to get it started. Then continue normally.
CNTLM says I don't need another proxy but I still can't connect to drop
21-11-13 Tutorial: How to use Dropbox behind a corporate proxy server using CNTLM | I code and code
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box
Make sure to go over the dropbox connection checklist [https://www.dropbox.com/help
/23/en] :
Allow "Dropbox" (or "Dropbox.exe" in Windows) access to ports 80 (HTTP)
and 443 (HTTPS)
The LAN Sync feature [https://www.dropbox.com/help/137] requires access t
o port 17500 (recommended)
Add Dropbox to your firewall's list of approved websites (whitelist), or make
sure it's not on its blacklist
You may need to allow "*.dropbox.com" to access the internet
I don't want to just leave my password in the config file!
Have a look at the advanced tutorial [http://icodeandcode.blogspot.com/2012/10/advanc
ed-cntlm-secure-configuration.html] .
NEW Error: 'cntlm' is not recognized as an internal or external command
,
operable program or batch file.
You're not running cntlm from its installation directory, which is probably C:\Program
Files (x86)\Cntlm. In the cmd window, type cd C:\Program Files (x86)\Cntlm and p
roceed normally.
Posted 20th February 2012 by Eran Goldin
Labels: bypass, CNTLM, corporate firewall, corporate proxy, Dropbox, guide, how-to, tutorial
Replies
53 View comments
dvirus February 21, 2012 at 5:27 PM
nice, CNTLM might be useful for other stuff to.
Reply
Eran Goldin February 21, 2012 at 8:47 PM
Yeah, it's useful for a lot of things that can't deal with your proxy at work. :)
Reply
ptupper May 1, 2012 at 8:39 PM
What about a corp network that doesn't appear to use a proxy server but in IE >> Connections >> LAN settings uses a proxy script? Because I need a password to run cntlm -M http://google.com.
Reply
attached May 30, 2012 at 1:17 PM
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No need for test, just continue with further steps..it worked for me, I am behind MS TMG with proxy script!
attached May 30, 2012 at 1:18 PM
and many thanks to author on this great tutorial
Reply
Eran Goldin June 7, 2012 at 3:21 AM
You're welcome buddy! :D
Anonymous May 31, 2012 at 5:13 PM
It works! Thank you for posting.
Reply
Eran Goldin June 7, 2012 at 3:21 AM
:D
Anonymous July 19, 2012 at 2:31 PM
Not sure whats going but when I try the step 3)cntlm -M http://google.com I get asked for my password and then the following:=========================================================Password:Config profile 1/4... Auth not required (HTTP code: 301)Config profile 2/4... Auth not required (HTTP code: 301)Config profile 3/4... Auth not required (HTTP code: 301)Config profile 4/4... Auth not required (HTTP code: 301)
Your proxy is open, you don't need another proxy.=========================================================
I definitely have a proxy as I cannot get to dropbox :(
Reply
Eran Goldin July 26, 2012 at 2:19 AM
That simply means that your proxy does not require any authentication. CNTLM is an authentication proxy and is therefore not needed.
The fact that you can't connect to dropbox tells us there is something else in the way. Perhaps dropbox is blocked in your corporate proxy.
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I assume you have already tried entering the details of your work proxy server and port in dropbox?
Anonymous September 19, 2012 at 12:36 PM
Have indeed, must be a corporate proxy :(
Eran Goldin October 8, 2012 at 10:24 AM
Have a look at the checklist in the FAQ. If you have any control over these issues, that is.
Anonymous October 9, 2012 at 4:23 PM
I don't, BUT Google drive is working ;) Will use that instead :)
Anonymous July 2, 2013 at 4:37 PM
Same here, Google Drive it is :P
Anonymous August 3, 2012 at 2:13 PM
Hi can not get the auth through the command line....
Reply
Eran Goldin August 4, 2012 at 2:03 PM
Please be more specific :)
Anonymous August 6, 2012 at 9:32 AM
Thank you,
so in the the third step when I run the certain command, I get something like "...the command is in not an internal or external valid command" (translation from greek)and secondly in the workstation part I changed the "netbios_hostname" to my pc's actual name-correct? I don't know...FInally, when I start the session it seems that...it starts...however when I configure dropbox I get connction error....Thanks again!
Reply
Eran Goldin September 21, 2012 at 7:28 PM
Note that you have to run that command from command line when you are IN THE CNTLM INSTALL DIRECTORY.
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Also, there's no need to change anything in the preferences beyond what this tutorial suggests. Besides, the netbios portion you've mentioned is COMMENTED OUT and means nothing unless UNCOMMENTED.
Naturally if it is misoconfigured, dropbox will not succeed in connecting.
Let me know if you need more help! :)
Anonymous September 19, 2012 at 6:59 PM
How does it work if the company only uses an adress to a proxy script? Then i have no proxy adress and no port!
Reply
Anonymous January 3, 2013 at 12:25 PM
Does anybody have a solution for Proxy-Auto-Config Scripts??
Eran Goldin January 7, 2013 at 2:27 PM
It's still possible to sniff out your proxy server using various http debug tools.
Anonymous October 2, 2012 at 3:59 AM
Too bad. I can't even install CNTLM thanks to "You must be logged in as an administrator when installing this program". (Win XP). Sigh.
Reply
Eran Goldin October 3, 2012 at 9:58 AM
I will add that to the tutorial very soon. :)
Anonymous October 10, 2012 at 8:31 PM
It worked!! Thank you very much!
Reply
Agus December 18, 2012 at 5:42 PM
I followed your tutorial. Now I can synchronize my Google Drive folder behind proxy. Thank you very much.I have to skip step 3. I got respond something like "cntlm command is not recognized". But it worked.
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Eran Goldin January 2, 2013 at 5:18 PM
That's great! Happy to hear.Luckily your proxy uses the same authentication method as mine. Incase others get the same error, I've added that to the FAQ.
Anonymous January 3, 2013 at 12:26 PM
Does anybody have a solution for Proxy-Auto-Config Scripts??
Reply
Eran Goldin January 7, 2013 at 2:25 PM
You could try and locating the proxy server address and proceed as usual.
Anonymous January 10, 2013 at 5:34 PM
Config profile 1/11... Connection closedConfig profile 2/11... Connection closedConfig profile 3/11... Connection closedConfig profile 4/11... Connection closedConfig profile 5/11... Connection closedConfig profile 6/11... Connection closedConfig profile 7/11... Connection closedConfig profile 8/11... Connection closedConfig profile 9/11... Connection closedConfig profile 10/11... Connection closedConfig profile 11/11... Connection closedYou have used wrong credentials, bad URL or your proxy is quite insane,in which case try submitting a Support Request.
This is the output i am getting when I am trying to test.Help me please..
Reply
Eran Goldin September 11, 2013 at 6:21 PM
Have you configured cntlm.ini properly? Are you using encrypted or plaintext credentials?
Luigi Palumbo February 12, 2013 at 5:15 PM
No work :( and in my browser I cant see https://www.dropbox.com site blocked
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by policy :(any idea?thank's a lot
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Eran Goldin September 11, 2013 at 6:24 PM
Your corporate proxy is blocking the dropbox server. You can't use your corporate network to connect to dropbox as they are intentionallypreventing from doing that.
You can try and bypass your corporate proxy by using a different public proxy; this will result in failing to access your corporate intranet unless you can configure multiple proxy servers.
However, I recommend against it, as this would probably be frowned upon by your organization.
Saad Nassar March 7, 2013 at 5:25 PM
Hello, when I get to step 3 I get something about a POSIX paths. I cant get past this. Help please.
Reply
Eran Goldin September 11, 2013 at 6:26 PM
This is not an error, just a warning.
Felix March 14, 2013 at 3:34 PM
Great, now i can continue using dropbox. Thanks!!!
Reply
Unknown April 7, 2013 at 12:09 AM
Has someone tried this where dropbox, googledrive are blocked by firewall? The also do a certificate spoof so they can view https traffic
Reply
Anonymous April 9, 2013 at 2:14 PM
Thanks.. It works.. specially step 4 helped me a lot to configure cntlm.
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David Warner April 23, 2013 at 1:05 PM
I have a great way to access incorporate sector in very easy way . Just a one click and you can access dropbox no need to install any software and long proxy
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patterns. I hope everybody will use this simple way. Access Dropbox from school
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Devang Patel June 18, 2013 at 2:49 PM
Thanks a lot This work like a charm i ' ve been in search for solution long time
Reply
Eran Goldin September 11, 2013 at 6:27 PM
Happy to help! :)
Anonymous June 21, 2013 at 8:17 PM
Hi, it is not working with me. I can enter in the www.dropbox.com site. But whenI try to connect with he dropbox app, it did not work.
I need to use the 'PassNTLMv2 xxxxxxx' that the cntlm -M command show?!
Reply
Eran Goldin September 11, 2013 at 6:28 PM
No. If you follow the instructions exactly it should work.
Nemesis June 30, 2013 at 2:31 PM
in the command line after providing password it's showingConfig profile 1/4... Connection to proxy failed, bailing out
Could you please help me what should I do? Thanks
//Sajib
Reply
Eran Goldin September 11, 2013 at 6:28 PM
Either your credentials are wrong, or your proxy address/port are wrong.
Abhishek Mishra July 17, 2013 at 5:34 AM
Hi Eran, many thanks for that post, it was a revelation :)... the concept is workin
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g for me ( testing for google etc if OK ) but somehow it is not handled by DropBox... the username sent to the corporate proxy by cntlm is \None instead of the one configured against "Username" variable in the .ini file and hence "Access is Denied". Should I check for typo or formatting somewhere?
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Abhishek Mishra July 17, 2013 at 6:43 AM
Correction, this should be the username sent by Dropbox itself as the commandline tests for cntlm are successful, but there is not much options in DropBox, still not able to make this work...
Reply
Eran Goldin September 11, 2013 at 6:30 PM
I believe your proxy connection should cause dropbox to prompt for ausername and password.
Did you manage?
Anonymous July 26, 2013 at 5:02 PM
What if the company is blocking the application (i.e., Dropbox.exe).
The suggestion to "Allow "Dropbox" (or "Dropbox.exe" in Windows) access to ports 80 (HTTP) and 443 (HTTP)" assumes you're able to modify the firewall and port settings. But aren't these usually controlled from a central location and pushed to all corporate PCs on the network? For example, in the firewall program on my corporate PC I see no option to edit or customize the firewall rules related tospecific applications and ports.
Thank you for any suggestions.
Reply
Eran Goldin September 11, 2013 at 6:31 PM
If your organization actively blocks dropbox, there's nothing you can do that a normal user would do.
Storm Rider September 13, 2013 at 7:11 PM
when I run cntlm -M http://google.comIt ask me for a password ?? Help plz
Reply
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