/dev/posts/

Intel AMT discovery

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There has been some articles lately about Intel Active Management Technology (AMT) and its impact on security, trust, privacy and free-software. AMT supposed to be widely deployed in newest Intel hardware. So I wanted to see if I could find some AMT devices in the wild.

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Number of lines of code with FlameGraph

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FlameGraph is used to display stack trace samples but we can ue it for other purposes as well.

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IP over UDP tunnel with socat

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A simple way to create IP over UDP tunnels using socat.

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DNS aggregation over TLS

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In a previous post, I tried different solutions for tunnelling DNS over TLS. One of those solutions was using a dedicated DNS-over-UDP fake service replying to all queries with the truncate flag set: this was causing the stub resolvers to retry the query using a TCP-based virtual-circuit. This solution is interesting because it is dead simple (it fits in a few line of codes) but it is clearly a hack. Here, I am using a dedicated DNS forwarder aggregating all the incoming DNS-over-UDP requests over a single persistent TCP virtual-circuit.

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Debugging use-after-free with RR reverse execution

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RR is a very useful tool for debugging. It can record the execution of a program and then replay the exact same execution at will inside a debugger. One very useful extra power available since 4.0 is the support for efficient reverse execution which can be used to find the root cause of a bug in your program by rewinding time. In this example, we reverse-execute a program from a case of use-after-free in order to find where the block of memory was freed.

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Multiple accounts with mutt

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If you try to use mutt, you will wonder how you are supposed to handle multiple accounts. You will find suggestions to bind some keys to switch to different accounts, use hooks.

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Private PostgreSQL instance

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How to create a private on-demand PostgreSQL instance accessible only for the local user over UNIX socket.

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The ELF file format

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Some notes on the ELF 🧝 file format with references, explanations and some examples.

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SimGridMC: The Big Split (and Cleanup)

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In my previous SimGrid post, I talked about different solutions for a better isolation between the model-checked application and the model-checker. We chose to avoid the (hackery) solution based multiple dynamic-linker namespaces in the same process and use a more conventional process-based isolation.

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FTL data file

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Faster Than Light (FTL) is a very nice (and quite difficult) rogue-like-ish game with space battles, teleporters, management of the energy of your ship, asteroid fields, alien species, droids (drones), etc. It is quite cheap, DRM-free and available natively on Intel-based GNU/Linux. These are notes taken while trying to find out the format of the .dat files of the game containing the game assets, ships statistics, events, etc. when I had not access to the internet to find the solution. There is a companion C program, ftldat, for extracting the files within the archives and generating archives. Unsurprisingly, similar tools with the same name already exists. However, the description of the process of reverse-engineering a (very simple) binary format might be interesting for someone out there.

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