8 ms·
Speed or security?... Age old question.
by djjaxe 12y ago
Speed or security?... Age old question.
- ibotty 12y agono. read the article.
- djjaxe 12y agoI read the article is does not mention speed, performance once, in which it had nothing to do with what I stated. I was simply stating that higher level languages will cause the library to be slower also less easy to be used by other high level languages like python.
- spc476 12y agoThe author has several articles about ATS (http://bluishcoder.co.nz/tags/ats/ http://bluishcoder.co.nz/tags/ats/) and from what I've read, it outputs C code that is proven (for the parts that are in ATS) to be correct. There's a bit more detail in "Safer handling of C memory in ATS" (http://bluishcoder.co.nz/2012/08/30/safer-handling-of-c-memory-in-ats.html http://bluishcoder.co.nz/2012/08/30/safer-handling-of-c-memo...) and the end of the article contains some generated C code.
- slight 12y agoI think you should read the article again. The language in question isn't higher level really it just has compile time type checking, which has no overhead.
- djjaxe 12y agoThat's still not my point. At the time of starting openssl I don't believe that ATS was around. In any case my point is that back then C lang was the best choice for performance and still is revered as the "fastest" as `nearly` all other languages are written on top of it either directly or indirectly. In any case I would love to see someone tell all of the openssl community to just drop C and switch to a different language.
- danieldk 12y agoC being loved in the UNIX community is one of the primary reasons that these libraries are in C. Ada has been around since the beginning of the eighties, has and had performance that is near that of C, does not use a garbage collector, provides C linkage, and is far more safe than C. If you do allow garbage collection, there were many performant and safe alternatives in the 90ies, such as ML. It's culture as much as performance.
- djjaxe 12y agoAda is a higher language weather or not it has linkage to C or not. The UNIX community cares about performance, performance, performance.
- Dewie 12y ago'Higher level' doesn't necessarily say anything. Rust and ATS are both higher level than C, but they can both do everything that C does. Is Ada less performant than C? I know it has bounds checking, but that can be turned off for "shipped" software. Does it have some features that incur a runtime cost and that can't be disabled?
- Avshalom 12y agoAda with all the runtime features left on is slower than comparable quality C. It's faster than most languages though. With all the runtime turned GNAT can/should produce code with in a percent or two as fast as GCC (they share the same backend). And Ada has a thing called SPARK which is a set of compiler checks to formally verify your code so you can provably turn off those runtime features safely. https://en.wikipedia.org/wiki/RavenSPARK https://en.wikipedia.org/wiki/RavenSPARK
- djjaxe 12y agoSo rust & ATS & ADA & higher level languages can modify memory space? That I am aware of most higher level languages stray from being able to modify memory space on purpose as it's dangerous but, someone has to do it for the operating system is all I am saying about low level now that we are completely off topic here.
- sitkack 12y agoI do not understand why people keep pushing unsafe code when computers keep getting faster and we have more and more headroom (cpu, memory, bandwidth). There is no excuse to keep running unprovable crypto.
- djjaxe 12y agoMaybe because most of the code currently out there being use by the biggest companies in the world still use these "unsafe" languages. & tons of the job market still is in these "unsafe" languages.
- ohazi 12y agoBoth! http://rust-lang.org/ http://rust-lang.org/
- djjaxe 12y agoLOL "* In theory. Rust is a work-in-progress and may do anything it likes up to and including eating your laundry."
- Pacabel 12y agoIt's a shame to see that comment has been downvoted. That's a quote directly from the bottom-right corner of the Rust website itself! Rust is promising, without a doubt. But it's not yet truly usable in the same sense that C, C++, Java, Python, Haskell, Go and so many other languages are. Maybe it'll start to get to that point once 1.0 is released, once we see at least some language and library stability, and then perhaps some adoption. But that just hasn't happened yet.
- Dewie 12y agoWhat some one - I think kibwen - has brought up is that early adopters can benefit in the sense that the language design is still in flux. So these early adopters can uncover weaknesses in the design, before they get to the stage where they have to consider backwards compatibility. So although early adopters might not get any useful software out of learning Rust at this stage, they might indirectly improve their future Rust code by having a small influence on the direction of the language.
- steveklabnik 12y agoI downvoted it because "LOL" is not the kind of comment I'd like to see here. The point could have been made in a more substantial way. Like you just did.
- djjaxe 12y agoWow sorry I can't laugh at something jeez. So, you have never in your life just felt like re-posting a quote off something and just added a little something to it to show the spirit in which it was meant to be. Now you are just being nitpicky and to be honest rude in a sense. I have just joined this community I am trying to fit in and you just come along and see the comment and you "don't like it" because it's short, sweet and too the point. I am laughing at the comment of the programmer of rust for the quote he put on his site and now you have just totally bashed me because you felt it necessary to not like my simplistic comment. Wow.
- kilburn 12y agoIf you are speaking about execution speed, you got the idea wrong. From a quote in the article: > If you use the high level typing stuff coding is a lot more work and requires more thinking, [...] (but) you can even hope for better performance than C by elision of run time checks otherwise considered mandatory, due to proof of correctness from the type system. Expect over 50% of your code to be such proofs in critical software and probably 90% of your brain power to go into constructing them rather than just implementing the algorithm. It's a paradigm shift. The idea is to formally prove that the code is not doing unexpected things. The process is relatively simple to understand: First you define the assumptions you make about the program, its execution environment, and the acceptable/expected results of your program. This is known as "formal specification" of the program. It is a critical part. If your specification is wrong, then the whole approach breaks down. However, this part should be much smaller than your whole codebase, and hence you can be extra careful on it. Next, using this specification, you write proofs showing that the code can not do anything unintended (such as accessing a buffer out of its valid range). The compiler goes through this proofs and checks that everything is provably correct (according to the specification). Then it can generate code without runtime checks that you would otherwise probably implement, because it is sure that certain things cannot happen. As a result, the code may end up being actually faster. Although a bit involved, the idea should be pretty intuitive. It is exactly what you are doing in your mind when programming. The main differences are: 1. We humans are pretty comfortable working with inexact and/or incomplete specifications. Then some undefined behavior happens, and our programs bug out. For instance, it is very easy for us to think about the division operator as something that always yields a value, ignoring the "division by zero" edge case. Computers are not, and force you to specify what exactly should happen when you encounter such edge cases. 2. We are also pretty bad at exhaustively checking every possibility, whereas computers excel at it. With the help of human-written proofs, obviously (otherwise verifying a program would involve checking every possible input for it, which is obviously intractable). TL;DR: The tradeoff here is between development and compilation speed versus correctness, which implies improved security and execution speed.
- Dewie 12y agoNo. I think that the article clearly shows: execution speed, safety, programmer productivity ← pick any two
- alkonaut 12y agoThis isn't a fundamental dilemma like the consistency/scalability dilemma of databases. This is (or was) just a limitation of languages and compilers. The arguments for using C are many but in this case the most common involve the need for low level access (for perf, timing) C is certainly very much suited for some parts of an SSL implementation e.g. when you need absolute deterministic performance to avoid timing attacks etc. (Although performance should certainly be good enough with modern compilers for most languages, and avoiding side-channel attacks by having deterministic execution time is also possible without resorting to C). Using the execution speed as an argument for writing the whole thing in C is just wrong. I haven't heard any good arguments as to why a library such as OpenSSL shouldn't be written in Haskell (or say 98% Haskell and 2% C). Did someone at some point say "There is 2% of the code that is performance critical and/or needs low-level code for cryptographic reasons so I'll write everything including the network code, command line argument parser, world, dog and kitchen sink in C" ?
- Dewie 12y ago> This isn't a fundamental dilemma like the consistency/scalability dilemma of databases. This is (or was) just a limitation of languages and compilers. You're right. Null pointers are a nuisance in some languages, but other languages have shown that you can remove them and still have just as much of an expressive language (and the compiler can still translate pointers that might be "null" to actual null enabled pointers, so no performance cost). Rust might show that a stronger type system can remove certain raw pointer flaws from the language while still retaining both execution speed and programmer productivity. Dependent types might mature to the point that you can use them and gain both execution speed, productivity and safety - time will tell. > Using the execution speed as an argument for writing the >whole thing in C is just wrong. I haven't heard any good >arguments as to why a library such as OpenSSL shouldn't be >written in Haskell (or say 98% Haskell and 2% C). Did someone at some point say "There is 2% of the code that is performance critical and/or needs low-level code for cryptographic reasons so I'll write everything including the network code, command line argument parser, world, dog and kitchen sink in C" ? ... The article makes the argument that, assuming that the whole program needs to be incredibly performant, you can write say 2% of it in verified ATS code, the rest in C-ish ATS code (ie. without proofs). I guess you can also choose to write 2% verified low-level code, and the rest in a more high level ATS - ATS is a functional language with garbage collection and I presume other high level goodies that functional programmers are used to.
- doublec 12y agoThe type safety shown in the article doesn't come at a speed cost. The times are erased during code generation. The generated C code is much like hand crafted C but with the safety confirmed via the types.