Portmaster is a free and open-source application firewall that does the heavy lifting for you. Restore privacy and take back control over all your computer's network activity.

There are many tools that we can use for SSO, such as Authelia, Authentik, or Keycloak.

Although some of the aforementioned SSO tools may be easier to set up, I decided to go with Keycloak. Keycloak is an enterprise-level tool that is supported by Redhat. Using Keycloak will give us a lot of flexibility, and ticks the boxes for acceptable memory usage, theme-ability, and multi-factor authentication support.

We analysed several authenticator apps after Twitter had stopped the SMS method for 2FA. We saw many scam apps looking almost the same. They all trick users to take out a yearly subscription for $40/year. We caught four that have near identical binaries. We also caught one app that sends every scanned QR code to the developer’s Google analytics account.

Är du förberedd om krisen kommer? Så här packar du en krislåda med grejer för att klara dig i upp till en vecka - till exempel om du drabbas av ett långvarigt strömavbrott.

The world’s most widely used web app scanner. Free and open source. Actively maintained by a dedicated international team of volunteers.

RSA is an intrinsically fragile cryptosystem containing countless foot-guns which the average software engineer cannot be expected to avoid. Weak parameters can be difficult, if not impossible, to check, and its poor performance compels developers to take risky shortcuts. Even worse, padding oracle attacks remain rampant 20 years after they were discovered. While it may be theoretically possible to implement RSA correctly, decades of devastating attacks have proven that such a feat may be unachievable in practice.

espoofer is an open-source testing tool to bypass SPF, DKIM, and DMARC authentication in email systems. It helps mail server administrators and penetration testers to check whether the target email server and client are vulnerable to email spoofing attacks or can be abused to send spoofing emails.

But while there are many tools to automatically renew certificates for publicly available webservers (certbot, simp_le, I wrote about how to do that 3 years back), it's hard to find any useful information about how to issue certificates for internal non Internet facing servers and/or devices with Let's Encrypt.

This is a different way to learn about crypto than taking a class or reading a book. We give you problems to solve. They're derived from weaknesses in real-world systems and modern cryptographic constructions. We give you enough info to learn about the underlying crypto concepts yourself. When you're finished, you'll not only have learned a good deal about how cryptosystems are built, but you'll also understand how they're attacked.

This page explains use cases and examples of SSH tunnels while visually presenting the traffic flows.