8051enthusiast - Network

neat little fact about CRCs and stream ciphers: if you append a CRC to a message, you always get the same CRC.if you encrypt the resulting...

neat little fact about CRCs and stream ciphers: if you append a CRC to a message, you always get the same CRC.
if you encrypt the resulting message with a stream cipher, the CRC of the message is cancelled out so you essentially get the CRC of the keystream. as a result, if you encrypt 2 different files of same length with CRC appended with the same (unsalted) key, you get the same CRC on the encrypted file

Content warning:spoiler (aoc 2024 day 22)my solution for today's aoc part 1 (i precalculated everything)

Content warning:spoiler (aoc 2024 day 22)

my solution for today's aoc part 1 (i precalculated everything)

current status: regular wifi dropouts, except when running tcpdump on the wifi interface, in which case it works just fine

current status: regular wifi dropouts, except when running tcpdump on the wifi interface, in which case it works just fine

yay graphs

yay graphs

finally bought binary ninja, let's see how good i can bend it to 8051s pecularities

finally bought binary ninja, let's see how good i can bend it to 8051s pecularities

Content warning:explanation (spoiler)the function first gets the return address of the caller but uses it to read 3 bytes after the call...

Content warning:explanation (spoiler)

the function first gets the return address of the caller but uses it to read 3 bytes after the call instruction, which are not actually instructions but the jump target address and bank. it then pushes the original bank value and the target address, and jumps to the target address using the `ret`. the original bank is restored using a special return function which picks the remaining byte from stack

found a function for banked function calls i haven't seen before (note how it pops before it pushes)

found a function for banked function calls i haven't seen before (note how it pops before it pushes)

i got myself a new desktop PC, so I looked at the bios and of course there is 8051 firmware inside it

i got myself a new desktop PC, so I looked at the bios and of course there is 8051 firmware inside it

created a python script that uses delsum to find checksummed chunks in an unknown file format by looking at all checksummed regions and...

created a python script that uses delsum to find checksummed chunks in an unknown file format by looking at all checksummed regions and checking for the most common offset between the end of one checksummed region and the start of the next.
using png as an example, it finds that it uses crc-32, with a gap of 8 bytes between checksummed chunks (because of the 4 byte checksum field and the 4 byte length field)

(also just made another release to avoid generating the wfa2 bindings at build time so that cargo install doesn't fail if you don't...

(also just made another release to avoid generating the wfa2 bindings at build time so that cargo install doesn't fail if you don't have libclang installed)

i've released a new biodiff version, with support for the WFA2 library (which has the biwfa algorithm that does alignment with linear...

i've released a new biodiff version, with support for the WFA2 library (which has the biwfa algorithm that does alignment with linear memory usage) and a new --print option

https://github.com/8051Enthusiast/biodiff/releases/tag/v1.2.0

large language volume manager (llvm), for managing large volumes of programming languages

large language volume manager (llvm), for managing large volumes of programming languages

i apparently got someone to cite the name "8051Enthusiast" in a published paper

i apparently got someone to cite the name "8051Enthusiast" in a published paper

btw, apparently you can just mmap a whole 1tb hdd into your process

btw, apparently you can just mmap a whole 1tb hdd into your process

had some fun making a (terrible) programming language for parsing binary data and a visualizer for its output (left parses the gpt table for...

had some fun making a (terrible) programming language for parsing binary data and a visualizer for its output (left parses the gpt table for a hdd, right a fat32 partition)

might post more again, but also might not, i really do not know!

might post more again, but also might not, i really do not know!