Archive for the ‘TCP’ Category
Posted by jpluimers on 2019/05/21
Since many HTTP stacks do not have fields for this so it’s hard to get the originating IP address:
It is about these HTTP header fields with and without X- prefix:
ForwardedX-Forwarded-ForX-Forwarded-ByX-Forwarded-Proto
Note that widely used tools like HAProxy do not always fully adhere to the “standard”…
Via:
–jeroen
Posted in Communications Development, Development, HTTP, Internet protocol suite, Software Development, TCP | Leave a Comment »
Posted by jpluimers on 2019/03/15
For me, scp is like tar; somehow I Google this every time…
- On the remote machine, find out the full path of the remote file:
~ # ssh username@192.168.71.123
...
~ # ls -alh `find /vmfs/volumes/ | grep -w W81Entx64CI | grep '\.vmdk$'`
-rw------- 1 root root 200.0G Aug 26 22:48 /vmfs/volumes/552f5788-33e30274-8dba-001f29022aed/VM/PSO/W81Entx64CI/W81Entx64CI-flat.vmdk
-rw------- 1 root root 500 Aug 19 16:36 /vmfs/volumes/552f5788-33e30274-8dba-001f29022aed/VM/PSO/W81Entx64CI/W81Entx64CI.vmdk
- On the local machine, go to the right directory, then copy the file from the remote machine:
~ # cd /vmfs/volumes/Samsung512NVME/PSO/VM/W81Entx64CI/
~ # time scp -v username@192.168.71.123:/vmfs/volumes/552f5788-33e30274-8dba-001f29022aed/PSO/W81Entx64CI/W81Entx64CI-flat.vmdk W81Entx64CI-flat.vmdk
I don’t know what’s worse–the fact that after 15 years of using tar I still can’t keep the flags straight, or that after 15 years of technological advancement I’m still mucking with tar flags that were 15 years old when I started.
The last line will logon over ssh and shows the file transfer in a verbose way.
Requirements:
- both machines have ssh
- local machine has firewall entry to allow client ssh
- remote machine has sshd and firewall entry to allow sshd server connections
Via [WayBack] shell – How to scp a folder from remote to local? – Stack Overflow (thanks [WayBack] Gryphius)
Image source: [WayBack] xkcd: tar
–jeroen
Posted in Communications Development, Development, Internet protocol suite, SSH, TCP | Leave a Comment »
Posted by jpluimers on 2019/02/21
From the geek fun department: [WayBack] IP over Avian Carriers – Wikipedia.
I learned through this slightly after the fight to keep HTTP status code 418 (I’m a teapot) which is part of RFC2324 released on April 1st, 1998.
The IP over Avian Carriers is part of three RFCs, all released on April 1st in various years:
–jeroen
via: Http-statuscode ‘I’m a teapot’ is voorlopig veilig – IT Pro – .Geeks – Tweakers
Posted in Communications Development, Development, Fun, Geeky, HTTP, Internet protocol suite, Software Development, TCP | Leave a Comment »
Posted by jpluimers on 2019/02/13
Of course you don’t want this. So by the time you read this, the connection has been closed.
For testing some Internet of Shit stuff from a client that cannot do SFTP, I needed a temporary FTP accessible connection.
These links helped:
TL;DR:
- Preparing the USB stick:
- Ensure the USB disk is FAT/FAT32/NTFS
- Create a directory in the root of the USB disk for the FTP user (for now:
FtpDirectory)
- Insert the USB disk in the Fritz!Box
- Logon to the Fritz!Box web UI
- Configure a user for FTP:
- In the menu, go to
System, then FRITZ!Box Users
- Click
Add user
- Name the user (for now:
MyFtpUser)
- Ensure that user *only* has a checkmark for `Access to NAS contents`
- Click the button
Add directory
- In the popup click
Select folder
- Choose the
FtpDirectory you just made
- Click
OK
- Ensure the
read and write checkboxes are enabled
- Click
OK
- Configure the USB stick for FPT access
- In the menu, go to
Home Network, then USB Devices
- Observe if the device is visible and has the correct file system (if not: ask AVM)
- In the menu, go to
Internet, then Permit Access
- Click on the
FRITZ!Box Services
- Ensure there is a checkmark at
Internet access to your storage media via FTP/FTPS enabled
- At
TCP Port for FTP/FTPS, fill in 21 (many IoT devices cannot use a different port)
- Ensure there is *no* checkmark at
Allow only secure FTP connections (FTPS)
- Make a note of the value after
FTP address (something like ftp://example.org:21`)
- Click
Apply
- Test
–jeroen
Posted in Communications Development, Development, Fritz!, Fritz!Box, FTP, Internet protocol suite, IoT Internet of Things, Network-and-equipment, Power User, Software Development, TCP | Leave a Comment »
Posted by jpluimers on 2019/01/22
Note: if the system you SSH from is ever compromised, then assume the passwordless targets are also compromised!
–jeroen
Posted in *nix, *nix-tools, Communications Development, Development, Internet protocol suite, Linux, openSuSE, Power User, SSH, SuSE Linux, TCP, Tumbleweed | Leave a Comment »
Posted by jpluimers on 2019/01/16
With the advent of WebSockets, it looks like TCP tunnels over HTTP/HTTPS are gaining more ground and I need to put some research time in them.
Some old to new links:
CONNECT requests are not supported by many HTTP proxies, especially in larger organisations, so chisel and crowbar have a much bigger chance there.
And of course there is SoftEtherVPN/SoftEtherVPN: A Free Cross-platform Multi-protocol VPN Software. * For support, troubleshooting and feature requests we have http://www.vpnusers.com/. For critical vulnerability please email us. (mail address is on the header.).
However, that is a VPN solution which is much broader than just a single TCP tunnel. You can so similar things with OpenVPN, but over HTTP/HTTPS, also requires CONNECT:
SoftEtherVPN seems to be more versatile though. I blogged about that before, but back then didn’t have needs for it yet. VPN over HTTPS: Ultimate Powerful VPN Connectivity – SoftEther VPN Project.
–jeroen
via: [WayBack] VPN through only http – Server Fault answer by [WayBack] neutrinus
Posted in Communications Development, Development, HTTP, https, Internet protocol suite, Network-and-equipment, OpenVPN, Power User, TCP, VPN, WebSockets, Windows-Http-Proxy | Leave a Comment »
Posted by jpluimers on 2019/01/15
Though the Google Calendar UI does not support EXRULE and EXDATE to exclude certain slots (via dates or rules) from recurring events.
The API supports them: [WayBack] Google Calendar API, RRULE and EXDATE – Stack Overflow
–jeroen
Posted in Communications Development, Development, Google, GoogleCalendar, HTTP, Internet protocol suite, Power User, REST, TCP | Leave a Comment »
Posted by jpluimers on 2018/12/24
If you want to setup an account on your system that will be used only to transfer files (and not to ssh to the system), you should setup SFTP Chroot Jail.
This explains how: [WayBack] How to Setup Chroot SFTP in Linux (Allow Only SFTP, not SSH)
Posted in *nix, *nix-tools, Communications Development, Development, Internet protocol suite, Power User, SFTP, SSH, TCP | Leave a Comment »
Posted by jpluimers on 2018/12/12
Having mainly used ssh as a means to connect to a shell on remote machines and occasionally a manual port forward.
I never noticed autossh where you can automate the ssh logon process to keep permanent port forwards up and running. Cool!
It’s on my research list now, as this will be useful probably sooner than later:
My initial impression is that autossh is a wrapper around the regular ssh client that allows reconnection upon communication failures.
–jeroen
Posted in *nix, *nix-tools, Communications Development, Development, Internet protocol suite, Power User, SSH, TCP | Leave a Comment »
Posted by jpluimers on 2018/11/08
Based on:
- Download the most recent x64 Apache binaries for Windows from [WayBack] Apache VC15 binaries and modules download (at the time of writing: https://www.apachelounge.com/download/VC15/binaries/httpd-2.4.34-win64-VC15.zip )
- Extract recursively to
D:\bin
- Run the UltrawareController locally
- Run
D:\bin\httpd-2.4.34-win64-VC15\Apache24\bin\ab.exe -n 1000 -c 10 http://localhost:8000/foo
This will run the ab Apache benchmark tool with 1000 connections using 10 threads all doing the same http GET request at http://localhost:8000/foo
If you want to test TLS (https) connections, then you need to use the abs tool in the same directory as the ab tool supports http-only (when you still try, you get the message SSL not compiled in; no https support as explained in [WayBack] Add https support to Apache Bench on Windows – Stack Overflow).
Download location via [WayBack] windows – Is there any link to download ab Apache benchmark – Stack Overflow:
There are many more command-line parameters documented at [WayBack] ab – Apache HTTP server benchmarking tool – Apache HTTP Server Version 2.4, this is the summary:
Synopsis
ab [ -A auth-username:password ] [ -b windowsize ] [ -B local-address ] [ -c concurrency ] [ -Ccookie-name=value ] [ -d ] [ -e csv-file ] [ -f protocol ] [ -g gnuplot-file ] [ -h ] [ -Hcustom-header ] [ -i ] [ -k ] [ -l ] [ -m HTTP-method ] [ -n requests ] [ -p POST-file ] [ -Pproxy-auth-username:password ] [ -q ] [ -r ] [ -s timeout ] [ -S ] [ -t timelimit ] [ -Tcontent-type ] [ -u PUT-file ] [ -v verbosity] [ -V ] [ -w ] [ -x <table>-attributes ] [ -Xproxy[:port] ] [ -y <tr>-attributes ] [ -z <td>-attributes ] [ -Z ciphersuite ] [http[s]://]hostname[:port]/path
Via: [WayBack] apache – ab load testing – Stack Overflow
––jeroen
Posted in Communications Development, Development, HTML, HTTP, Internet protocol suite, Software Development, Web Development | Leave a Comment »
The Wiert Corner - irregular stream of stuff 