JasuM · HackerTrans

3 дня назадdiscuss

Doesn't this mean that the broken device also answered to every ARP request? And wouldn't that break the network by itself, regardless of DHCP behavior?

JasuM

7 лет назадdiscuss

Makes sense. I was thinking that maybe signal handlers could use the regular stack of the thread, but that would of course make everything fall down if the "real" code would write to the stack before updating the stack pointer.

JasuM

7 лет назадdiscuss

Oh yeah, I didn't think of that. I wonder if you could write a signal handler carefully to not allocate any memory, stack or otherwise, or is some return address or an internal structure being allocated transparently...

JasuM

7 лет назадdiscuss

What happens if you really run out of physical memory (including swap) after overcommitting? Does your process get a signal, or will OOM killer just run without notifying the process that triggered the condition?

JasuM

7 лет назадdiscuss

My dad used a 3D printer with a Dremel attached to carve PCBs. The PCBs were those that you normally etch, i.e. they had a full copper coating.

JasuM

7 лет назадdiscuss

This one's my favorite (although I haven't read the whole thing):

"This movement is designed to double the speed by gears of equal diameters and numbers of teeth—a result once generally supposed to be impossible. Six bevel-gears are employed..."

http://507movements.com/mm_226.html

JasuM

7 лет назадdiscuss

I can imagine some timing-specific attacks for memory accesses, but they're not likely as robust as attacks against the branch-predictor:

1. This is the simplest one - if the memory being accessed is in a cache (L1/L2, or page in TLB), the function will take a significantly shorter time to execute. If movfuscator achieves conditional execution by manipulating index registers to perform idempotent operations, this will be very easy to detect.

2. Prefetching - if movfuscator reads memory sequentially with a detectable stride, prefetching will shorten the execution time.

3. Write combining - if the code writes to nearby addresses (same cache line), the CPU will combine them to a single write. This will cause a measurable timing difference.

EDIT: One more: Store forwarding - if the code writes to a memory address and reads it soon, the CPU may bypass the memory access (and even cache access) completely.

JasuM

8 лет назадdiscuss

- Random stuff all over ~/

- User-specific bin folder ~/LocalApps (with lots of scripts)

- Projects etc. in a GoCryptFS-encrypted directory synced with Syncthing with NAS (with NFS+Kerberos on my desktop rather than Syncthing). Vendor-directories (/vendor/, /node_modules/) are not encrypted as not to slow down development, they are bind-mounted to a cleartext directory.

- PDFs, MP3s, etc. in Dropbox

JasuM

9 лет назадdiscuss

I spent yesterday rewriting my ZSH config. A lot of the time I spent on figuring out how to map random key combos to unused control characters. So if I could implement both the terminal and the shell from scratch (or make a significant addition), I would implement a scenario like this:

  1. Program informs the terminal that it supports "extended keyboard input". This would be done with an escape code, much like bracketed paste.
  2. Terminal informs the program that it is now enabled.
  3. Terminal informs the program of the initial modifier key state.
  4. When the user presses a key (including modifiers), it is sent in a format that standardizes over all the commonly used key codes. Also, if the key represents a Unicode codepoint, that is sent as well. E.g. (mod-status-at-key-press)(key-code)(utf8-char-or-null)(null-terminator).
  5. When the user releases a key, a similar message would be sent.
  6. When the program exits (or a shell runs another program), it asks the terminal to disable "extended keyboard input"

JasuM

9 лет назадdiscuss

Its port 26 enforces TLS though.

JasuM

9 лет назадdiscuss

Requiring the same standard of verification for activating an account. Of course, they want to make it easy so it's unlikely to happen...

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