Monthly Archives: July 2024

Fun with regex: We match the requirements for the HTTPS DNS record type defined by RFC 9460

Linux, PHP, , ,

To be able to fully read, understand and transfer RFCs into a standard-aligned application can be very difficult. You may become a lawyer as well.

We start off with section 2.1 of RFC 9460 which defines the following rules for us to apply:

  • the record data must be formatted as “SvcPriority TargetName SvcParams” where
    • SvcPriority is a number between 0 and 65535
    • TargetName is a domain-name, which is a combination of texts (labels) that can contain alphabetic characters, digits and hyphens, these labels can be up to 63 characters each and can be bonded together using dots up to a length of 255 characters
      • Note: The domain-name is not specified in RFC 9460, but already in RFC 1035
    • SvcParam is one or more of either only a key such as ‘mykey’ or a key-value pair such as ‘mykey=”myvalue”‘ where the quotation mark is mandatory
Continue reading Fun with regex: We match the requirements for the HTTPS DNS record type defined by RFC 9460 →

Compile SquirrelMail imapproxy with OpenSSL 1.1.1 and 3.0

Linux,

imapproxy is a application aware (POP3/IMAP) proxy, which enables webmailers such as SquirrelMail or Roundcube to save on roundtrips by using a local low-latency connection to a mail server over a high-latency connection that is being kept open.

SquirrelMail as well as imapproxy is very outdated software and you may not want to use it. However, if you really want, you may want to compile it yourself as shown in the rest of this article.

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Calibrating Epson Perfection V850 Pro with X-Rite Monaco IT8 reflective target and creating a colour profile for SilverFast

Windows

Last year, I acquired an Epson Perfection V850 Pro, also known as the GT-X980. The package included both transparency and reflective targets for calibration from X-Rite. In my specific case, these targets were not accepted by either the auto-calibration or the manual calibration in SilverFast.

The auto-calibration failed because the targets are not original targets from LaserSoft Imaging AG. The manual calibration in SilverFast failed because the delta value was allegedly far too high, which I personally attribute to a software error. This is because the manual calibration and creation of a colour profile with X-Rite, as shown below, did not reveal such a problem.

Continue reading Calibrating Epson Perfection V850 Pro with X-Rite Monaco IT8 reflective target and creating a colour profile for SilverFast →

Dovecot “get_public_key(INBOX) failed: […] Mailbox attributes not enabled”

Linux, OSS, ,

If you use Dovecot as a IMAP or POP3 server, and you have looked around how to secure and design your setup, you propably came across the mail-crypt plugin for Dovecot. The plugin enables you to store mails in an encrypted manner, basically to do so called “encryption at rest”.

Continue reading Dovecot “get_public_key(INBOX) failed: […] Mailbox attributes not enabled” →