All posts by unmanarc

Seguridad informática, programación, sistemas de información, electrónica, Investigación y desarrollo, Redes, Sistemas distribuidos, linux, bsd, criptografía, c++, pentesting, pruebas de penetración, servidores, Digital Forensics, raw sockets, ethical hacking, network security, c#, base de datos, postgresql, databases, firewalls, linux from scratch, appliances, hardware interfaces, iptables, voip, rfc, network protocols, SQL, php, network monitoring
Audio, Linux

HiFi/HiRes Audio in Linux/Pipewire

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First off, I want to say that I’m not an audio expert, but I could say I’m an enthusiast, so don’t expect anything marvelous from what I’m writing… Initially, I had an old SoundBlaster X-Fi (below average), I used it with the RCA output and a converter to 3.5mm, eventually, I upgraded to a FiiO BTR15 DAC and was surprised that with newer hardware I couldn’t achieve an audio quality level anywhere close to what I had with my SoundBlaster.

Spoiler alert: This journey is crazy, since not everything is as “plug and play” as one would hope, so I decided to see what would happen if I thoroughly checked and finally found some configuration parameters that greatly improved the audio quality.

Continue reading HiFi/HiRes Audio in Linux/Pipewire →
Fedora, Linux, System Administration

Things to test in fedora 40 KDE (no X11)

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I have a personal list that I want to test in Fedora 40 with KDE 6… I will update the results after the release…

  • KeePassXC AutoType
  • ssh -X (I want to execute some visual app from a remote host running F40 and from F40)
  • Installing it in a qemu/kvm VM… (and GUI performance!)
  • KRFB (VNC)
  • xrdp
  • fullscreen sharing (like google meet, zoom?)
  • program sharing thumbnails
  • HIDPI behaviour (4K)
  • Nvidia card performance…

Cryptography, Information Security, Linux, Network Administration, System Administration

Solving the openvpn_execve Error in LXC

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Problem Description:

When running OpenVPN in an LXC environment, users may encounter a specific error that prevents the OpenVPN service from operating correctly. The error manifests as follows:

Jan 08 00:56:47 fw openvpn[404]: openvpn_execve: unable to fork: Resource temporarily unavailable (errno=11)
Jan 08 00:56:47 fw openvpn[404]: Exiting due to fatal error
Jan 08 00:56:47 fw systemd[1]: openvpn-client@yourvpn.service: Main process exited, code=exited, status=1/FAILURE
Continue reading Solving the openvpn_execve Error in LXC →
Linux, System Administration

Installing VirtualBox-7.0 in OpenSUSE 15.x (or tumbleweed) from repo and UEFI Secure Boot Enabled

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This is a simple/short how to for installing VirtualBox 7 in OpenSUSE 15

Here we are handling two problems:

  1. There is no repo for OpenSUSE 15.4 (we need to do a trick)
  2. There is no documentation on how to create proper UEFI secure boot MOK’s (owner keys) for the newer OpenSUSE which demands that the key will have special attributes like “codeSigning“

so, here is the answer:

Continue reading Installing VirtualBox-7.0 in OpenSUSE 15.x (or tumbleweed) from repo and UEFI Secure Boot Enabled →
Information Security, System Administration

Security Risk Without a CVE

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Most security assessments only includes CVE’s and known vulnerabilities but many fail to address the true potential security risks. And this will create a big problem for your organization.

The problem starts because most organizations only wants to have a security analysis based on know-existent vulnerabilities, like a “tell me what KB to patch”, but this approach is not good and fails to protect you in two ways:

Continue reading Security Risk Without a CVE →