dfox

45 ms·

601.
by dfox 6y ago
PFS still involves asymmetric cryptography. And in fact in essentially every modern cryptography stack (ie. (EC)DLP-based) the "PFS primitive" (Diffie-Hellman, ie. scalar multiplication/exponentiation) is the one thing that e
602.
by dfox 6y ago
Which is prime example as to how C does not consider timing to be observable behavior. What the code does is that it tries to specify the operation in sufficiently complex way that makes compiler give up on any optimizations.
603.
by dfox 6y ago
This apparently is about driving the ePaper correctly to produce intended image and not just using it as dumb framebuffer. The demo firmware for above mentioned M5Paper seems to have some support for intelligent driving of the display, sadl
604.
by dfox 6y ago
That is certainly true, but there is reason why "the zeroth freedom" is "zeroth" and why GPL is worded the way it is in regards to that. Then there are licenses that completely depend on such a provision being obvious (s
605.
by dfox 6y ago
That is almost certainly reference to several open source projects where building the thing from source and distributing the resulting build artifacts is "legally problematic" because of trademarks. In the 00's this was giant
606.
by dfox 6y ago
The main difference to especially GPL is that GPL does not say anything about how you can use the software (to the extent that it actually explicitly says that there are no restrictions on how you use the software and such restrictions are
607.
by dfox 6y ago
Similar kind of ambiguity is even in GPLv2. ie. what does "anything that is normally distributed with..." in section 3 mean and how all that interacts with notionally GPL licensed software which depends on 3rd party components wit
608.
by dfox 6y ago
During the last 20 years the typical x86 box went from single CPU, through multiple CPUs, through multiple CPUs with non-trivial NUMA topology to the current state where not having non-trivial NUMA topology is meaningful point in marketing
609.
by dfox 6y ago
Most of the color names come from X11 rgb.txt which was not exactly "designed" to be anything and also many entries assume RGB color space of some particular Unix workstation which was decidedly non-sRGB (eg. using significantly d
610.
by dfox 6y ago
I don't have reference for that but I always though that CPP directives are preceded by # because the character was previously used as comment delimiter by something (probably csh). In the grand scheme of things cpp is somewhat modern
611.
by dfox 6y ago
"The idea of a neural network dated back to the 1950s, but the early pioneers had never gotten it working as well as they’d hoped. By the new millennium, most researchers had given up on the idea, convinced it was a technological dead
612.
by dfox 6y ago
Well I'm long time emacs user who switche to emacs from vi(m) in essentially the time it took to go through the C-h t tutorial. While today I dont't use Emacs as the day-to-day editor (I use VSCode, for a bunch of not entirely goo
613.
by dfox 6y ago
It is not that way today but for a long time the entry-level Cisco IOS router was PowerPC based, while the highend was invariably MIPS. On the other hand both architectural choices had nothing to do with the architecture and everything to d
614.
by dfox 6y ago
You probably mean "TIMI" which is the user-visible ISA of IBM's "midrange" systems (ie. AS/400 or System/i) which was from the start meant as virtual machine ISA that is then mostly AOT transpiled into wha
615.
by dfox 6y ago
My aversion to such systems is primarily motivated by the fact that every one of such system somehow penalized resubmissions. I probably don't have anything against "you have to write program that is compiled by this gcc/llvm
616.
by dfox 6y ago
My experience with C courses with this structure of automatically validated home works not only filter "the weak" but also people with previous (especially C on Unix) experience, because nobody with any kind of practical Unix expe
617.
by dfox 6y ago
For me the moral of the story is do not use (whatever)scanf() for anything other than toy programs. In most cases implementing your own tokenizer (for both of these cases of reading numbers that involves str(c)spn() to get length of candida
618.
by dfox 6y ago
I will also try. In field effect transistor (in which the actual physics involved are at least for me simpler to grasp) the gate is isolated from everything else and voltage at the base directly changes the geometry of the conductive channe
619.
by dfox 6y ago
Semiconductor manufacturing is essentially the interchangeable parts engineering taken to the extreme. The tolerances are so large (relative to the feature size) that instead of trying to eliminate them you exploit the relations between var
620.
by dfox 6y ago
What you need timer interrupt for is “true” preemptive multitasking/threading. For many applications that makes quite large difference in programmer comfort (ie. you can just run CPU-bound computation without any regard to yielding to
621.
by dfox 6y ago
> Do all non-optical network cards have a similar analog circuit as well? Is this generally the transceiver chip on the card? Even optical cards have this kind of circuitry in the PHY chip. While the SFP module usually contains surprisin
622.
by dfox 6y ago
I think that main issue in this is the pyca/cryptography library itself and its unfortunate name. It bundles three only marginally related things (high-level symmetric encryption API, X.509 handling and bunch of cryptographic primitive
623.
by dfox 6y ago
I have read the actual ISO 8601 spec. It is somewhat typical wall of prose ISO standard that contains meaningful conformance distinctions which depend on two words in the middle of 10+ line paragraph. For me, more significant reason to pref
624.
by dfox 6y ago
“Porn mode” is bad name for the thing because for the typical porn use case the user actually wants the persistent persistent browser state (eg. so that pornhub’s “Recommended for you” shows relevant content) and only wants it to be disconn
625.
by dfox 6y ago
Because transmission gate literally are two transistors. Standard two input logic gate contains four. So for example you can build two to one multiplexer from two transmission gates for total of four transistors while implementing the same
626.
by dfox 6y ago
Most general purpose ISAs (eg. SPARC and IIRC RiscV has something similar) with some kind of intrinsic support for tagged pointers also prefer the tags in low order bits. And you are right that the tag inside address trick involves allocati
627.
by dfox 6y ago
The reason why amd64 checks whether the addresses are “canonical” is discourage exactly this trick. On almost all platforms that simply ignored upper byte of pointer (m68k, s390, IIRC even early ARMs) this lead to significant compatibility
628.
by dfox 6y ago
Is there any reason why one would want CSI <huge-number> D instead of plain old CR?
629.
by dfox 6y ago
The stated purpose is to allow detection of strings that should not be publicly disclosed. If such string would also plainly identify what it is good for it would essentially defeat the purpose. Ie. the authors want to encourage creation of
630.
by dfox 6y ago
This seems to be the case. On the other hand mostly everybody ignores the fact that open(2) is documented as possibly returning -EINTR, because it essentially never happens (in particular, network filesystem are usually implemented in a way

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