cnvogel · HackerTrans

cnvogel

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USB 3.1 now has digital signatures: may force you to use vendor chargers only

usb.org

63 pointsby cnvogel10 yıl önce65 comments

This christmas is day #55555 on astronomers' timescale (modified julian date).

leapsecond.com

25 pointsby cnvogel16 yıl önce8 comments

DeleGate: Multiprotocol proxy/plumbing-tool/converter [TCP,SSL,HTTP,NNTP,DNS…]

delegate.org

3 pointsby cnvogel16 yıl önce0 comments

comments

2 yıl öncediscuss

Here’s what I don’t get: why the many layers of obfuscation in the build phase? (I understand why in the binary linked into ssh.)

Once the first stage, extracting a shell script from one of the „test“ data blobs, has been found it was clear to everybody that something fishy is going on.

It’s inconceivable that I’ve would have found the first stage and just given up, but then it was „only“ a matter of tedious shell reversing…

They could easily done without the „striping“ or „awk RC4“, but that must have complicated their internal testing and development quite a bit.

7 yıl öncediscuss

You are not observing the "problem" of entropy running low. Because it doesn't.

You are observing the misguided attempts of fixing this non-problem.

7 yıl öncediscuss

https://www.qualcomm.com/products/qualcomm-9205-lte-modem

The Qualcomm® 9205 LTE modem is our next-generation ...

Qualcomm 9205 uses the latest generation (gen9) Qualcomm® GNSS engine ...

Location

Satellite Systems Support: GPS, GLONASS, Beidou, Galileo ...

7 yıl öncediscuss

Yes, that's certainly a solution.

Or using a certification authority for users (TrustedUserCAKeys in sshd_config), so that any user that has a signed certificate, and owns the corresponding private key, would be allowed to login. No further updates of authroized_keys files needed.

And, to further automate the ssh login, maybe your LUKS container could have a second (Nth) key-slot being a random key RSA-encrypted with the other machine's identity private key? (https://bjornjohansen.no/encrypt-file-using-ssh-key for examples)

But generally, I really dislike the use of LUKS in this case, as I think a filesystem based encryption (not encrypting whole block devices) would make more sense. I understand that this isn't as mature as LUKS, though.

7 yıl öncediscuss

> Also I’m curious about the 1-bit recording. Is that a thing?

Yes. This homemade GPS receiver uses a simple comparator (1 bit) to sample the signal (after amplification to get the noise floor over the decision threshold).

http://www.aholme.co.uk/GPS/Main.htm

7 yıl öncediscuss

Here's a paper that shows reflections (Fig. 3, "S11") and insertion loss (Fig. 4, "S12") on coplanar waveguides, when using a sharp 90° bend, a 90° bend with a champfer and the case where the bend is replaced by two successive 45° turns ("final design").

The frequency scale spans 10..90 GHz.

http://tentzeris.ece.gatech.edu/ECTC09_Rida.pdf

8 yıl öncediscuss

The examples should only view the bit/address mapping, not be a complete example on how to access memory mapped peripherals.

8 yıl öncediscuss

It's still non-esoteric today:

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc....

ARM Cortex M4 supports adressing individual bits (often registers of hardware peripherals) of memory locations as one additional memory location writing to, or reading from a single bit.

e.g., from the examples of said infocenter url:

   *(uint32_t*)0x20000000 |= (1<<7)
   *(uint32_t*)0x20000000 &= ~(1<<7)

should be equivalent to

   *(uint32_t*)0x2200001C = 1;
   *(uint32_t*)0x2200001C = 0;

Also Analog Sharc DSPs (which, I think, still are being sold with this architecture, and still used, even though I've used them only 10 years ago) alias their memory four times, depending if you want to access it as 16bit, 32bit, 48 or 64bit data.

9 yıl öncediscuss

Quote from the Article: """The figure is calculated by multiplying 2 by itself 77,232,917 times and then subtracting 1."""

Would HN agree that multiplying 2 by itself once is 2⨯2 = pow(2,2), twice is 2⨯2⨯2 = pow(2,3) and N times yields pow(2,N+1)?

The Mersenne Prime found is pow(2,77232917) − 1, hence the article got the number wrong?

9 yıl öncediscuss

The ban is specifically for the ability of the watches to covertly record or transmit audio, not about GPS logging.

9 yıl öncediscuss

https://www.python.org/dev/peps/pep-0238/

{Describing the old python-2 behavior:}

-------- Quote: -------

The classic division operator makes it hard to write numerical expressions that are supposed to give correct results from arbitrary numerical inputs. For all other operators, one can write down a formula such as xy*2 + z, and the calculated result will be close to the mathematical result (within the limits of numerical accuracy, of course) for any numerical input type (int, long, float, or complex). But division poses a problem: if the expressions for both arguments happen to have an integral type, it implements floor division rather than true division.

-----------------------

To guarantee the correct mathematical behavior in python2, one would probably have to write:

    def true_math_div(a,b) :
        if type(a) is int or type(a) is long :
            a = float(a)
        if type(b) is int or type(b) is long :
            b = float(b)
        return a/b

as a and b could be int, float, complex, or some object defining the method __div__.

9 yıl öncediscuss

There is no general relativity involved in calculating your position. Solving for your position is basic geometry, if you want to have better resolution, have good model for the effects of the atmosphere on the radio waves.

http://www.aholme.co.uk/GPS/user_position_solution.pdf

9 yıl öncediscuss

Another example:

    $ nohup ./long_running_process &
    $ logout

Previously: long running process continues running after you logout. Recent change in systemd: Process is reaped once your login session ends (depending on flags passed via ./configure when systemd was compiled, your distro of choice might not be affected right now).

You could interpret this as "breaking user-space", as it's contrary to long-running practice and user-expectations.

Or you could say that systemd is superior as it's reliably cleaning up unwanted lingering processes which may have bothered some before. And this is worth the hassle of explicitly running intended background processes via systemd-run(1), or adding code to e.g. tmux/screen doing the equivalent via the dbus-api.

9 yıl öncediscuss

A DAQ that reconstructs a perfect square wave (or a perfect stair-step function) is employing a "Zero Order Hold", and it would make a god-awful audio DAC.

https://en.wikipedia.org/wiki/Zero-order_hold

With a 0OH you'd gain the ability to potentially reconstruct a infinite bandwidth signal (the squarewave), which is irrelevant in the audio case: With a 10kHz squarewave, the next harmonic would be at 30kHz which is already waaaay out of the human range of hearing.

But limiting the bandwidth of a DAC (or ADC) is the fundamental property which causes it to be able to perfectly reproduce the frequencies within its bandwidth (~up to 20kHz in HiFi Audio), so that's desirable. And the "ripples" on top of a squarewave are just the manifestation of this property: If you cut away the frequencies above Nyquist, you get a rippled squarewave. And conversely if you compute the difference between the perfect squarewave and the "rippled" squarewave you get out of an Audio DAC this only contains (non-audible) energy outside of the bandwith of the DAC!

9 yıl öncediscuss

> They didn't say "convert to greyscale".

Very good point. But even then, assume that one page of a leaked document contains a large picture with areas around the thrshold value: With the agency being able to recreate a perfect replica of the initially scanned paper version, but without yellow dots, it might be possible to extract the (very few) bits necessary to boil it down to a single printer serial number by statistical methods.

9 yıl öncediscuss

Yes, b/w converting is not sufficient. Once printed, the yellow dots are hard to remove.

http://imgur.com/a/kLovh

And even when you mask them out so that they are no longer visible in the "all white" (paper) background, e.g. by messing with the white/black point of the image there's still the possibility that they could be recovered with correlation methods in grey areas where they aren't visible to the naked eye or just by increasing the contrast.

9 yıl öncediscuss

From the datasheet (linked on the website):

Housing type: DIN rail housing (for DIN rail version EN 50022) Housing material: Polycarbonate

9 yıl öncediscuss

If you install the "moreutils", there's sponge doing the same.

https://joeyh.name/code/moreutils/ https://linux.die.net/man/1/sponge

9 yıl öncediscuss

What's that supposed to mean? Binary only, closed source kernel module?

>>> Drivers for both cards will be available ... as well as varieties of Linux (3.10, 3.12, 3.2, 4.2 and 4.4).

9 yıl öncediscuss

Yes, I know. And it's sad. I'm also not a "gui" person, and couldn't make a useful graphical interface if my life depended on this.

But I'm especially confused as why this hasn't been built into Windows for years, especially considering how many people were e.g. hurt by "Autoplay" in the old days:

    You've plugged in a device that claims to be...
        [ ] a mouse (driver available)
        [ ] a storage device (driver available)
        [X] a soundcard (driver will be downloaded and installed)
    Tick any of the functions you want to activate, or press CANCEL
    if you don't want to activate any functions of this device, e.g.
    because it's a phone you just want to charge from your laptop.

(of course the wording is utter crap, but you might get the idea...)