Artikel in Kategorie "GNU/Linux"

Generate Certificate Signing Requests (CSRs) for TLS Server Certificates

Overview In this article, a procedure is described to generate multiple certificate signing requests (CSR) for TLS servers, such as SMTP-, IMAP- or HTTP-servers, so that we can submit them to a Certificate Authority (CA). The CA will eventually perform the signature and return a public certificate to us. A Shell and the software OpenSSL […]

Methods of HTTP Caching

Preface I find the world wide web and the spectrum of methods and instruments that make it happen full of dubiousness and opportunity alike. Caching is generally known as one of the „hard problems“ of information science, and this is not different when it comes to technologies of the web. The text presented here, as […]

Protokoll meines Vortrags „Bourne Shell“ bei UUGRN e.V.

Ich hatte am 5.2.2021 die Ehre, einen Vortrag zum Thema „Bourne Shell“ auf der Veranstaltung FIXME der UNIX-User-Group Rhein Neckar, UUGRN e.V. halten zu dürfen. Hier ein Link zu den schriftlichen Aufzeichnungen dazu: https://wiki.uugrn.org/Bourne_Shell Abseits des Vortrags, den ich auch mit Live-Demos usw. durchgeführt habe, hat die Mitschrift nur begrenzten Nutzen, aber die Linkliste am […]

Python3 GTK3 TextView Drag-and-Drop Example

Just a small finger exercise …

Bourne to Bourne Again Shell Forward Compatibility

Note: This article is a work in progress; when i find the time, i will add more sections and examples. Introduction In this article i try to find out, if Bourne Shell scripts are runnable in Bourne Again Shell without modification. If not, i advice on how to modify the code so that it runs […]

Comparing Distinguished LDAP Names

In a Bourne Shell script, a distinguished name (DN) for performing an LDAP-query is held in a variable: dn=“cn=Malmø,ou=County Capitals,dc=Sweden,dc=Europe“ For the purpose of demonstration, this example DN contains a non-ASCII character. Let’s write a Bourne Shell function that escapes such special characters as requested by RFC 4514 using perl’s Net::LDAP::Util: canonical_dn() { perl -s […]

So it is possible …

Update August 28th 2021: I have identified some TLDs that apparently can be used for testing purposes. I have updated the text as indicated. … to have DNS top level domains for bargains (.bargain), the bible (.bible), black friday (.blackfriday) and marketing and social networking (.buzz), but it is not possible to have a TLD […]

Determining User Access on a Linux Filesystem with „Classic Permissions“

Introduction Looking at a Linux filesystem, checking if a certain file or directory is accessible for reading, writing or executing by certain users or groups poses interesting challenges. Let the basic and seemingly simple question be: „Given a user X and a file Y, can it be determined if X has access to Y, and […]