Artikel in Kategorie "Technik"

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 …

… 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 reserved for documentation and testing purposes. Instead, examples that use „example.com“ are in widespread circulation,  a domain which is owned by IANA but points […]

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 […]

The Backport of Bugfix #4864 to Squid Version 4

With SSL-bumping enabled, with an unpatched version of Squid, the service can crash with this errormessage:  !Comm::MonitorsRead assertion in HttpStateData::maybeReadVirginBody() This bug is fixed in Squid version 5, which was a sponsored effort by the developers of Squid. There is an effort of getting a bugfix into v4, which can be followed here. There also […]

Taking an Online Backup of a SAMBA-4 ActiveDirectory

Notes: The following procedure is available starting with SAMBA version 4.9. The procedure can be performed on a host that is unrelated to the domain, but one domain controller must be reachable, must be used as a nameserver at the time of the backup and have open ports for DNS (53/tcp and /udp) SSH (22/tcp), […]

Neue Foto-Galerie (mit alten Fotos)

Ich habe alle Fotos aus meiner alten Galerie in PhotoShow gekippt. →Zur neuen Galerie

Re-Enable TLS 1.0 for OpenSSL-based Clients on Debian Buster

OpenSSL shipped with Debian 10 „Buster“ disables TLS protocol versions below 1.2. The web-browsers Chromium and Firefox ship with an embedded SSL implementation and are not affected (they will issue warnings about legacy websites), but it can cause problems with curl, Squid and other clients that are linked against the OpenSSL. To re-enable TLS version […]