System administration on chuso.net

Splitting merged text files back into individual files

Sun, 27 Feb 2022 21:25:54 +0100

How to split back with POSIX standard tools text files that were merged into one single file.

A November patch introduces new conflicts in Active Directory

Wed, 12 Jan 2022 22:17:20 +0200

Since Novembmer ‘21 update, Active Directory new conditions may make it raise a CONSTRAINT_ATT_TYPE violation affecting other products.

Trusting invalid SSL certificates is wrong

Wed, 18 Nov 2020 20:31:24 +0100

So let me put it clear from the first line: trusting invalid certificates is wrong.

And now I will explain why it’s wrong and why there are few excuses for it.

We are talking here about certificates for SSL encryption, which serves basically two purposes:

Privacy — data is transferred encrypted and can only be decrypted by the intended recipient and not a third party wiretapping the line.
Authentication — making sure the receiving end that will be able to decrypt the data is who they claim to be and data is not diverted to a different receiver by a third party with access to manipulating our transfers.

Invalid certificates obviously defeat the second purpose of verifying the other end’s identity:

How I recovered the system after renaming ld.so

Mon, 14 Oct 2013 18:28:37 +0000

Yes, I know, it may be a little stupid renaming ld.so, can we skip this detail?
It's not something I do very often, but that day I felt like I had to innovate or something like that.

But innovation was a disaster, it is not a good idea to rename a library linked using its exact path by all system dynamic executables, just to take into account if you are going to have the same idea.