Skip to main content

Dealing with strict key checking for SSH

Problem:

While using sftp (or some other ssh related service) the following warning shows up and we can't use the service:


@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
b0:a8:eb:30:ce:1a:0e:6a:4d:7a:6b:3a:0a:c6:27:60.
Please contact your system administrator.
Add correct host key in /Users/xxx/.ssh/known_hosts to get rid of this message.
Offending key in /Users/xxx/.ssh/known_hosts:28
RSA host key for web.sourceforge.net has changed and you have requested strict checking.
Host key verification failed.
Connection closed

Solution:

Remove the key by doing
sed -i "28 d" ~/.ssh/known_hosts

We know it is line 28, because that came up in the warning message.

Comments

Popular posts from this blog

A note on Python's __exit__() and errors

Python's context managers are a very neat way of handling code that needs a teardown once you are done. Python objects have do have a destructor method ( __del__ ) called right before the last instance of the object is about to be destroyed. You can do a teardown there. However there is a lot of fine print to the __del__ method. A cleaner way of doing tear-downs is through Python's context manager , manifested as the with keyword. class CrushMe: def __init__(self): self.f = open('test.txt', 'w') def foo(self, a, b): self.f.write(str(a - b)) def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.f.close() return True with CrushMe() as c: c.foo(2, 3) One thing that is important, and that got me just now, is error handling. I made the mistake of ignoring all those 'junk' arguments ( exc_type, exc_val, exc_tb ). I just skimmed the docs and what popped out is that you need to return True or

Using adminer on Mac OS X

adminer is a nice php based sqlite manager. I prefer the firefox plugin "sqlite manager" but it currently has a strange issue with FF5 that basically makes it unworkable, so I was looking for an alternative to tide me over. I really don't want apache running all the time on my computer and don't want people browsing to my computer, so what I needed to do was: Download the adminer php script into /Library/WebServer/Documents/ Change /etc/apache2/httpd.conf to allow running of php scripts (uncomment the line that begins: LoadModule php5_module Start the apache server: sudo apachectl -k start Operate the script by going to localhost Stop the server: sudo apachectl -k stop