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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘TCP’ Category

Linux – How to Securely Copy Files Using SCP examples

Posted by jpluimers on 2020/03/16

I love short and to the point examples. The list of permutations for scp is at [WayBack] Linux – How to Securely Copy Files Using SCP examples.

–jeroen

Read the rest of this entry »

Posted in *nix, *nix-tools, Development, Internet protocol suite, Power User, SSH, TCP | Leave a Comment »

ssh – Why OpenSSH deprecated DSA keys – Information Security Stack Exchange

Posted by jpluimers on 2020/03/10

In a lot of ssh-keygen related posts, you still see DSA being mentioned, though that has been deprecated and later removed from OpenSSH.

I wondered why, so I did some digging.

TL;DR: it’s complicated:

  • different standards mandating eventually conflicting parameters,
  • extending the parameters would require protocol extension,
  • a logjam vulnerability for certain combinations of parameters and finally
  • better algorithms having become available.

Some of the related topics cannot be archived in the WayBack machine or refuse being archived at Archive.is, so here is a list of partially archived relevant links:

–jeroen

Posted in Communications Development, Development, Internet protocol suite, Power User, Security, SSH, TCP | Leave a Comment »

Redirect Detective – A Free Tool To Trace Where Redirects End Up

Posted by jpluimers on 2020/02/27

Cool tool, but be aware it does aJavaScript:xmlhttpPost from , so your data can be logged [WayBackRedirect Detective – A Free Tool To Trace Where Redirects End Up.

For http://www.xs4all.nl/~jp, it shows these redirects (where in bold I’ve listed the changes):

Oh and it runs this call: JavaScript:xmlhttpPost("/linkdetect.px")?word=www.xs4all.nl%2F%7Ejp from [WayBackredirectdetective.com/ajax.js.

Note that this shows more redirects than the plain http ones, so wget from [WayBack] wget – How do I display all URLs in a redirect chain? – Unix & Linux Stack Exchange shows this:

$ wget http://www.xs4all.nl/~jp 2>&1 | grep Location:
Location: https://www.xs4all.nl/~jp [following]
Location: https://jp.home.xs4all.nl/ [following]

–jeroen

Posted in *nix, *nix-tools, Communications Development, Development, HTTP, Internet protocol suite, Power User, TCP, wget | Leave a Comment »

Links to alternatives for Delphi REST clients

Posted by jpluimers on 2019/11/13

A few good links to a few alternatives for the built in Delphi REST client [WayBack] Hi looking for good and complete tutorial/course how to create RESTFul services with Delphi. Or if anyone use Delphi for creating RESTFul services feedb… – Gordan Paunovic – Google+

–jeroen

Posted in Communications Development, Delphi, Development, HTTP, Internet protocol suite, JSON, REST, Software Development, TCP | Leave a Comment »

Some links about the TCP SACK PANIC attacks on Linux and FreeBSD Kernels

Posted by jpluimers on 2019/06/20

The TCP SACK vulnerabilities as found by Netflix: [WayBack] security-bulletins/2019-001.md at master · Netflix/security-bulletins · GitHub.

Easy, but slow workaround from [WayBack] linux – How to disable TCP SACK for CentOS? – Super User:

Temporary (until boot):

echo "0" > /proc/sys/net/ipv4/tcp_sack

Permanent (even after boot):

echo "net.ipv4.tcp_sack = 0" >> /etc/sysctl.conf
sysctl -p

Coverage:

–jeroen

Posted in *nix, *nix-tools, Communications Development, Development, Internet protocol suite, Power User, Security, TCP | Leave a Comment »

 
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