Adding Dropbear SSH to EZSDK Linux for better debug support

That looks like what I want, but when I run the build it fails while compiling openssl. Numerous undefined references to things such as BIO_printf. I'm using a DM8168EVM, so I compiled it with MACHINE=c6a816x-evm bitbake dropbear

I know TI doesn't ship cryptography software in the SDK due to export regulations, do I have to add something not mentioned in the post? I also notice the work directory for the failed compile has "i686-linux" in the path, is this even compiling for the correct architecture? The work directory also has a armv7a-none-linux-gnueabi directory.

David

It looks like the errors are due to running Ubuntu 11.10. Apparently 10.04 doesn't have this problem. More info at http://gumstix.8.n6.nabble.com/openssl-native-compile-error-td630730.html 

They mention removing a line from openssl-native_1.0.0d.bb as a fix, but that didn't work for me. Setting Arago to use a slightly older version of openssl does seem to work.

Can't anyone give a straight answer around here,  its very anoying to have to refer to another post that's convoluted and doesn't really pertain to the question?

How do I get dropbear installed in the DM8168emv? A nice step by step answer would be nice.   I am new to Linux so that other thread was totally confusing, do I need to install a Apache web server just to install software????

Please can someone help me out?  the Linux environment is confusing enough to a newbie, having to decifier another thread is just plane frustrating.

Jeffrey,

The problem is that it is a fairly complex thing to do, so a really detailed step-by-step is very time consuming to write up. Many people here don't work for TI and are just trying to help out other people and share info when they can.

Basically, to build dropbear you have two options:

1) You can download the source from the http://matt.ucc.asn.au/dropbear/dropbear.html site and then modify the build so you can cross-compile it

2) You can use bitbake to build packages as part of the Arago Openembedded setup

I did give pretty detailed instructions for #2 in the 5th response in the thread someone else already mentioned:

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/t/131398.aspx

You are right that there is a steep learning curve for cross-compiling, especially if you aren't already familiar with Linux. You should expect it will take a while to figure out everything you need, and quite a bit of that time will probably be spent reading various threads and sites to see if anyone else has run into the same problem and has advice on how to solve it.

The nice thing about using OpenEmbedded is that it can be used to generate .ipk files which are easy to install into your filesystem using opkg. The bad things about OpenEmbedded is that it requires a fair amount of work to set it up, and the initial build will probably need to run overnight, because it is downloading and installing the base for everything it needs to do.

P.S. You don't need a web server to do the installation of packages once you've made them with OpenEmbedded. You can copy the .ipk files manually and use opkg on the copied file.

Thanks for the reply, and the encouragement.

I was able to download the source code and cross compiled it.  Then manually added it to the targets file system.  It seems to work, sort of, when the client tries to connect the server gives the message: 

Child connection from xxx.xxx.xxx.xxx:xxxxx .... Exit before auth (user 'root', 1 fails): Disconnect received.

I am not understanding this message?   I have the server set up for no password,root log in and the client doen't use the password either.

I am just connecting to a evm so security isn't needed.   The client gives the error password refused.  So I am little lost here.  If I disable using a password why isn't the connection being made?

I'm not an expert on dropbear, but I believe you have to generate keys for it. So if you haven't already done so, it would be something like this (run on the EVM):
dropbearkey -t rsa -s 1024 -f dropbear_rsa_host_key
dropbearkey -t dss -f dropbear_dss_host_key

Also, you may not be able to run without a password. Again, I'm not certain, but at least some applications are unhappy without passwords existing.

This thread has various suggestions for someone trying to install dropbear on a different embedded system (a router, in this case):

http://wl500g.info/archive/index.php/t-8619.html

not all will apply, but there are a couple of things to check.

Other than that, more googling is probably the way to go. Yes, it is time-consuming, but it sure is a lot easier than trying to write an SSH tool from scratch....

Thanks for the reply I have created the keys but used a slightly different syntax not sure what the difference would be, I guess I have to find documents on that unless you know?

dropbearkey -t dss -f dropbear_dss_host_key

dropbearkey -t rsa -f dropbear_rsa_host_key

Also FYI, I am following the bellow document to set up QT creator with the DM8168 evm,  it directs me not to use passwords, and I don't think I can setup a password on the evm, at least I don't know how.  

http://processors.wiki.ti.com/index.php/Qt_Creator_Embedded_Debugging_Setup

I will check out your link thanks

Bret you were right.

After setting a password for the root log in for the evm the ssh connect test successfully.

not sure where the problem was because I use the arg for dropbear not to use password, so it must be on the qt creator side.

so the original step-by-step I was following from TI was incorrect, it could not have work with a blank password.

Thanks for the replies.