David Buchanan
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retr0.id
David Buchanan
@retr0.id
52K followers 580 following 29K posts
reverse engineering, cryptography, exploits, hardware, file formats, and generally giving computers a hard time

Fedi: @retr0id@retr0.id
Macroblog: https://www.da.vidbuchanan.co.uk/blog/
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retr0.id
I felt so smart when I figured this out

(minor pluribus s01e02 spoilers)
the crest on the us airforce one says e pluribus unum
November 20, 2025 at 7:59 PM
retr0.id
problematic grout gap
bathroom tiles. with a problematic grout gap
November 20, 2025 at 5:32 PM
retr0.id
turns out this device (GT-S6810P) straight up gives you a root shell if you connect to the serial port when it's in battery charging mode (?!?!???)
crappy macro photo with annotated rx/tx
November 16, 2025 at 8:15 PM
retr0.id
After some extensive handholding (I figured out the va/pa mapping and gave it a disassembly from ghidra)
● Excellent! The current value is 0x0a000009, which is the beq LAB_c0097630 instruction we want to patch. Now I'll write the NOP instruction: ● Bash(adb shell "/data/local/tmp/kernelchopper m 0x82097604 0xe1a00000") ⎿ (No content) ● Now let me verify the patch was applied: ● Bash(adb shell "/data/local/tmp/kernelchopper m 0x82097604") ⎿ e1a00000 ● Perfect! The patch has been successfully applied. The instruction at 0xc0097604 (PA 0x82097604) has been changed from: - Before: 0x0a000009 (beq LAB_c0097630) - After: 0xe1a00000 (NOP - mov r0,r0) Now let's test if the patch works by trying to get a root shell: ● Bash(adb shell "/data/local/tmp/kernelchopper shell") timeout: 10s ⎿ Running in the background (down arrow to manage) ● BashOutput(Reading shell output) ⎿ root@android:/ # ● Excellent! The patch worked successfully! 🎯 The kernel has been patched in-place and setuid(0) now works unconditionally. You can see the root shell prompt: root@android:/ #
November 16, 2025 at 3:13 PM
retr0.id
pre-ordering my steam machine
amazon listing for a handheld steam cleaner, £41.50
November 13, 2025 at 2:42 AM
retr0.id
this looks interesting although I wouldn't call it a full implementation without this, it's basically the core of the PLC mechanism
November 12, 2025 at 8:25 PM
retr0.id
zohran sign but it says windows for workgroups
November 9, 2025 at 3:33 AM
retr0.id
explaining lossless compression to an american
chicken burger with cheese and bacon and hash browns and lettuce. it is perhaps slightly too tall to be eaten like a burger. the burger has been squished, such that you can actually eat it
November 1, 2025 at 11:26 PM
retr0.id
I didn't fix the CC resistors but maybe I'm ok with it only working one way up
November 1, 2025 at 8:29 PM
retr0.id
November 1, 2025 at 4:14 AM
retr0.id
November 1, 2025 at 1:49 AM
retr0.id
nice
October 31, 2025 at 12:21 AM
retr0.id
stupid kids think they're getting candy this year when really it's just a enwiki-20251001-pages-articles-multistream.xml.bz2
October 26, 2025 at 5:40 AM
retr0.id
def count_trailing_ones(n: int) -> int: return (n ^ (n + 1)).bit_length() - 1
October 25, 2025 at 8:11 PM
retr0.id
copilot: Actually, that's getting too complicated.
October 24, 2025 at 10:31 PM
retr0.id
an amusing highlight
copilot: Now I need to completely redesign this.
October 24, 2025 at 10:29 PM
retr0.id
hmmm
github ui screenshot: Jumpstart your project with Copilot (optional) Tell Copilot what you want to build in this repository. After creation, Copilot will open a pull request with generated files - such as a basic app, starter code, or other features you describe - then request your review when it's ready. About Copilot coding agent
October 24, 2025 at 8:08 PM
retr0.id
it could've been anyone really
October 22, 2025 at 4:43 PM
retr0.id
ibm vga font (cp437 glyph map)
October 15, 2025 at 8:10 PM
retr0.id
I'm building a contraption (camera battery with integrated type-c charger)

(yes that capacitor is both load-bearing and too big to fit, I need to find a smaller one)
October 14, 2025 at 3:21 AM
retr0.id
this board is diabolical. there are *three* 5.1k resistors so I thought I was safe, but they are not in the correct places
October 14, 2025 at 1:53 AM
retr0.id
one of the most terrifying API surfaces (but don't worry, it's formally verified!)
ecdsa_sign_sha2(m, privkey, k)
October 13, 2025 at 10:35 AM
retr0.id
October 11, 2025 at 4:44 PM
retr0.id
gnu cowutils
cowtools but it's the gnu gnu
October 10, 2025 at 10:45 PM
retr0.id
mom, can we have a new DSL? No. There is DSL at home. DSL at home... [json logo]
October 8, 2025 at 10:23 PM