i dove down the 7z rabbit hole (it goes deep)

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  • Опубликовано: 23 янв 2025

Комментарии • 1,2 тыс.

  • @LowLevelTV
    @LowLevelTV  Месяц назад +116

    Go check out Docker's security features! Secure your applications with docker scout: dockr.ly/4g4UdDJ

    • @isaacewing
      @isaacewing Месяц назад +6

      never!!! 😀🥰🤫 j/k

    • @LowLevelTV
      @LowLevelTV  Месяц назад +8

      ok

    • @PewPewPew_viper
      @PewPewPew_viper Месяц назад +2

      I have a weird question: What keyboard do you have? It's sounds so amazing.

    • @GOOGLE-IS-EVIL-EMPIRE
      @GOOGLE-IS-EVIL-EMPIRE Месяц назад

      ​@@PewPewPew_viperi have 33 years old mechanik one. Still works.
      Mitsumi yellow switches. 65 gram push for click.

    • @PewPewPew_viper
      @PewPewPew_viper Месяц назад

      ​@@GOOGLE-IS-EVIL-EMPIREoooo nice

  • @uis246
    @uis246 Месяц назад +1941

    1:01 7zip is opensource. 7z is open format.

    • @isheamongus811
      @isheamongus811 Месяц назад +66

      7za and p7zip open-source

    • @mo938
      @mo938 Месяц назад +185

      I’m open source drinking 7up

    • @AdrianDX
      @AdrianDX Месяц назад +31

      I’m closed-source playing 7Sins

    • @edwardmacnab354
      @edwardmacnab354 Месяц назад +60

      @@AdrianDX I'm proprietary and will tell you nothing

    • @realraven2000
      @realraven2000 Месяц назад +8

      Open format is new to me, what’s it?

  • @virtuosisimo
    @virtuosisimo Месяц назад +319

    most of the time you ask "I don't know why they did that" the answer is: "That's the way it was done then (20 years ago)"

    • @mattymattffs
      @mattymattffs Месяц назад +10

      Can you blame him? It was before he was born

    • @BrainDeath89
      @BrainDeath89 Месяц назад +38

      @@mattymattffs but he should know, because he is making Videos about it

    • @satsubatsu347
      @satsubatsu347 Месяц назад +50

      @@mattymattffs Yes, we can blame him for not doing a good enough job at researching the topic of the video and related topics to give a comprehensive and, most importantly, ACCURATE representation of what is going on.

    • @Cr3zant
      @Cr3zant 7 дней назад

      @@satsubatsu347 You're taking a joke about him being incredibly young very seriously.

    • @paradoxicalcat7173
      @paradoxicalcat7173 4 дня назад +1

      Well...I was around 20 years ago and I ask "why did they do that?". The language didn't change that much in 20 years. Sloppy programmers were even worse than they are now, and they are bad today. Don't get arrogant and think we're better today because we are not. We actually have far more nefarious ways of screwing up; some intentional.

  • @konstantinub
    @konstantinub Месяц назад +771

    11:17 If `COPY_CHUNK_SIZE` is greater than 1, `len` doesn't necessarily need to be zero. This is a do-while loop, which checks only for non-equality with zero. Since the values are unsigned, subtracting from any sufficiently small `len` (specifically, 0 ≤ `len` < `COPY_CHUNK_SIZE`) will cause the same underflow and out-of-bounds writes.

    • @LowLevelTV
      @LowLevelTV  Месяц назад +229

      Yeah good catch I realized this after I published

    • @rybavlouzi
      @rybavlouzi Месяц назад

      medžuslovjansky integer podtok

    • @TanerH
      @TanerH Месяц назад +79

      Yeah, came to comments to mention this. Checking for '

    • @ysakhno
      @ysakhno Месяц назад +56

      This would have been true, if not for the surrounding code. The initialization code _ensures_ `len` is always a multiple of `COPY_CHUNK_SIZE`. The only way `len` can become 0 (which is technically still a multiple of `COPY_CHUNK_SIZE `) at the start of the loop, is if `len` is ridiculously big (so adding `len += (COPY_CHUNK_SIZE - 1);` on line 1520 and then masking off the lower bits on the next line would yield 0). Then of course `COPY_CHUNK_SIZE ` is subtracted from zero at the end of the loop, and all trouble ensues.
      What they did wrong is they had gone with the do-while loop, instead of doing the for-loop, which checks _before_ entering the loop, then updates the variable at the end. (Or they could at least use the 'normal' while loop if they were being weird.)

    • @nickwallette6201
      @nickwallette6201 Месяц назад +25

      @@TanerH Haha.. I feel silly sometimes about checking for "

  • @RayBellis
    @RayBellis Месяц назад +1122

    It's funny that you used afl-gcc (named after American Fuzzy Lop, a domesticated rabbit species) to go down a rabbit hole...

    • @JayLooney
      @JayLooney Месяц назад +12

      I actually did not have a clue that it was a rabbit, I only knew of it as the software fuzzing tool, this is awesome :D

    • @unconnectedbedna
      @unconnectedbedna Месяц назад +9

      So it's the furry version of gcc? xD

    • @justingolden87
      @justingolden87 24 дня назад +1

      TOP TIER COMMENT

    • @darianjcarroll
      @darianjcarroll 23 дня назад +3

      As a rabbit enthusiast I approve of this.

    • @KodiakWoodchuck
      @KodiakWoodchuck 21 день назад +2

      @@unconnectedbedna All versions of GCC are furry.

  • @tau9632
    @tau9632 Месяц назад +619

    The first part is so hilarious - the discrepancy in level of expertise between 'compressing is making LARGE files SMALLER' and then jotting aorund at lightning speed between these different tools and codes and reports.. incredible.

    • @NihongoWakannai
      @NihongoWakannai Месяц назад +209

      "remember guys, faster things have MORE air resistance and slower things have LESS"
      "So anyway here are the aerodynamic properties of an F-22 fighter jet"

    • @wargreymon2024
      @wargreymon2024 Месяц назад +12

      LOL

  • @SianaGearz
    @SianaGearz Месяц назад +2232

    Typical code written by mathematicians, it's impenetrable to software engineers but it sort of makes sense within the context of specs and papers underlying it.

    • @lbgstzockt8493
      @lbgstzockt8493 Месяц назад +395

      Yeah, this looks like it was implemented straight from a research paper.

    • @InfiniteQuest86
      @InfiniteQuest86 Месяц назад +284

      @@lbgstzockt8493 I mean that's not even the problem. I'm sure the research paper didn't say use a bunch of macros and insane spacing and formatting. Naming something 'b' is far less egregious than all that craziness, especially if it really does tie back to a 'b' in the paper. Then it's perfectly understandable.

    • @jon9103
      @jon9103 Месяц назад +141

      ​@@InfiniteQuest86no one is saying the problem is that it's from research, they're saying those sorts of problems are common in research code.

    • @aliencray7269
      @aliencray7269 Месяц назад +19

      @@SianaGearz And most of the time this is real paper! Lucky you if you have a scanned pdf.

    • @Shonicheck
      @Shonicheck Месяц назад +77

      ​@@InfiniteQuest86 Yeah, i personally atribute it to the fact that Latex is macro language so most of the reaseraches are way too comfotable with macro-paradigme and want everything to be a macro(even if it means that it will be unreadable and umaintanable, since they are accustomed to turdy-code that has 20 pages of asterisks on how to circumvent issues and bugs)

  • @balsalmalberto8086
    @balsalmalberto8086 Месяц назад +854

    7zip devs: Patched in v24...
    Meanwhile: Debian, Ubtunu, Mint maintainers: v23

    • @Brahvim
      @Brahvim Месяц назад +86

      I'm on Debian and `7zip` is on version `22.01`. Meanwhile, I have `pzip7-full`, which is on version `16.*`, but in their versioning scheme, so...

    • @Ch40zz
      @Ch40zz Месяц назад +102

      classic package manager moment

    • @SaHaRaSquad
      @SaHaRaSquad Месяц назад +72

      Things like that are why I stopped using stable distros. Sooner or later you'll find a problem that only exists because a package is out of date, it's a law of nature.

    • @LordOfCake
      @LordOfCake Месяц назад +63

      Don't have this problem anymore... I use Arch, BTW :3

    • @olnnn
      @olnnn Месяц назад +90

      Normally they will backport the security fix to whatever version that is in the repository which results in some frankenversion because updating to a newer version will break policy because reasons. Ubuntu does occasionally allow bypassing this and update if there is a very compelling reason via a stable release updates process, debian only does it extremely rarely and are super strict about it.
      Apparently the version in debian stable is not affected as the code wasn't introduced yet...

  • @DezFutak
    @DezFutak Месяц назад +416

    I'm not a C developer, but you have an amazing way of explaining what would otherwise be a very dry topic in a fascinatingly entertaining & interesting manner. It's very cool to be able to watch "over your shoulder" and get some insights into the world of code, vulnerabilities, how to mitigate and so on. Keep on doing what you do, it's fab.

    • @LowLevelTV
      @LowLevelTV  Месяц назад +38

      thank you so much, that is very kind :)

  • @shamim64
    @shamim64 Месяц назад +162

    Didn't know that there are 7-zip haters until I read newest comments. It is by far the best of its kind that is truly free.

    • @kevinsedwards
      @kevinsedwards Месяц назад +7

      Me neither I've even recently began to love it

    • @checkoffgames
      @checkoffgames Месяц назад +31

      I didn't know such a kind of hater could exist.

    • @jakkaljakobie8774
      @jakkaljakobie8774 29 дней назад

      I've used 7zip over WinZip for years just because they don't heckle me.

    • @emilydavidson8844
      @emilydavidson8844 29 дней назад +8

      Winrar is just better

    • @kevinsedwards
      @kevinsedwards 29 дней назад

      @@emilydavidson8844 ?

  • @brandonw1604
    @brandonw1604 Месяц назад +2741

    7z? Should have used the xz utils, much safer.

    • @LowLevelTV
      @LowLevelTV  Месяц назад +881

      jia tan? 👀

    • @ArbitraryCodeExecution
      @ArbitraryCodeExecution Месяц назад +500

      the test files ensure its safety

    • @siddarthreddygsr
      @siddarthreddygsr Месяц назад +52

      @@LowLevelTV lmaoooo was about to say that

    • @matthias836
      @matthias836 Месяц назад +28

      legendary comment!

    • @hopelessdecoy
      @hopelessdecoy Месяц назад +160

      To be fair everything is safer until it is not. Bad actors are bad actors and they can be in any project.
      Same with mistakes in coding.

  • @Z3rgatul
    @Z3rgatul Месяц назад +455

    I disagree with your takes. This is algorithmic code. These variables can't have a name. Even if they would have meaningful names you will not understand the complex algorithm anyway.
    And even bigger problem is you always want to optimize algorithms, because they are really taking a lot of CPU. Optimized code becomes less readable.
    I have written in the past decompression functions. And that's how such type of code always looks like.
    6:45 - they are doing macros to optimize CPU cycles. common practice for decompression algorithms code

    • @Z3rgatul
      @Z3rgatul Месяц назад +184

      god i hate youtube. I literally reworded my comment 6 times just to not get shadow banned. i had to remove few key words and make my comment less informative

    • @S460-v2q
      @S460-v2q Месяц назад +8

      Hello! Can you please add some more detail or give some reading on the topic of optimizing CPU cycles with the macros? I am a beginner in C and haven't written any macros and I am curious why and how they are used here. Also, I am skeptical at all people who say that this is "just bad code".

    • @Z3rgatul
      @Z3rgatul Месяц назад +37

      @@S460-v2q I am not really C dev, I mostly program in C# (but I had to read a lot of C code). I don't know all the tricks you can do with macros, or where to read about them, but in short if CPU sees consequent instructions which are independent of each other it can run them in parallel. Instead of writing loop for i from 0 to 16, in most cases your code will work faster if you unwind this loop. The most easiest way is to use macros for such cases

    • @S460-v2q
      @S460-v2q Месяц назад +6

      @@Z3rgatul I don't really care if you are C dev, the important part for me was that you had knowledge about C. For that matter I am a nothing dev lol. I read a little bit about what you said and found the GCC docs containing a pragma for unwinding loops and looks cleaner. It has been added to gcc 8 though so probably the devs didn't have it and had to do it by hand.

    • @SimonBuchanNz
      @SimonBuchanNz Месяц назад +126

      I've written crypto, decompression and other math derived code too. The only reason you always end up with these terrible names is because the mathematicians who invented the algorithm you're implementing didn't give them meaningful names - but if you take the time tracing back the theory behind the RFC or whatever you realize they almost always *could.*
      It's often better to keep the terrible names anyway so it lines up with the paper, but that doesn't mean they're good names.
      (Side whinging: why the heck are Wikipedia maths articles so dang hard to read? The actual math textbooks are far easier most of the time, and those are for people that already have a math background!)

  • @citypavement
    @citypavement Месяц назад +869

    3:24 "This code is impossible to read" Oh good, I'm not as stupid as I thought I was. XD

    • @ysakhno
      @ysakhno Месяц назад +36

      What are you talking about? *All* C code looks like this. It is _impossible_ to write it differently. What names the variables have is irrelevant.

    • @m.projects
      @m.projects Месяц назад +192

      @@ysakhno uhm... just no.
      Decent naming scheme and proper structs & macros usage can lead to very readable C code, it's just hard to find.

    • @mhavock
      @mhavock Месяц назад +4

      That does not mean what you think, you could be at the bottom tier to begin with... just kidding 🤣🤣🤣

    • @k225
      @k225 Месяц назад +29

      😳 That's what all bit packing/compression code looks like to future self. It seems obvious when it's fresh in your head, until you come back to it 3 months later 😱

    • @keomg4718
      @keomg4718 Месяц назад +19

      @@ysakhno most people that follow this channel has no idea how to code, I don't expect more from a channel that just reads news. Making fun of open source projects instead of providing help. Classic youtuber.

  • @dsuess
    @dsuess Месяц назад +34

    TL;DR:
    * Download the latest 7-zip and you'll be okay

    • @gribkut
      @gribkut 5 дней назад

      Dang it, you spoiled half of this channel videos

  • @EximiusDux
    @EximiusDux Месяц назад +493

    Is forgetting to zip your pants a memory corruption bug?

    • @hopelessdecoy
      @hopelessdecoy Месяц назад +117

      No it is an illegal overflow of variable size lol

    • @thiscommentsdeleted
      @thiscommentsdeleted Месяц назад +45

      I can pen test but first I need to cut out your corrupted content. If I can't get access, I'll use the backdoor.

    • @Hellbending
      @Hellbending Месяц назад +15

      I’m worried about what casting would do in this circumstance 💀

    • @curtisstofer6678
      @curtisstofer6678 Месяц назад +37

      Might want to fix that dangling pointer.

    • @Anubis1101
      @Anubis1101 Месяц назад +7

      yes unfortunately the Paffendorf video had a buffer overflow and overwrote the memory block i was using to store zipPants()

  • @jeremydbjbjbjb
    @jeremydbjbjbjb Месяц назад +127

    I'm not entirely sure what this discussion is trying to tell me. It's a run of the mill overflow bug, could happen to anyone, it was reported and patched. And... that gets a sensational clickbaity video?

    • @brainsniffer
      @brainsniffer 28 дней назад +10

      @@jeremydbjbjbjb I think it’s more about it’s a run of the mill bug, this is how it works, this is how to avoid it, and a heads up to update. 7zip is everywhere.

    • @dannydetonator
      @dannydetonator 22 дня назад +3

      I agree to the first sentence. I know English reasonably well, but this was a dialect i have no clue about. Why am i here?😯

  • @macend
    @macend Месяц назад +132

    I love the RUclips algorithm. I have zero knowledge about programming, have never used 7zip (to my knowledge) and yet I have this video among my recommendations and I watched it. Only thing I understood was "compressing makes large files smaller". You are really entertaining.

    • @ag4p
      @ag4p Месяц назад +31

      It is pretty funny how much prior context you need to understand almost every word in this video

    • @TheeUnpleasantPeasant
      @TheeUnpleasantPeasant Месяц назад +10

      This just proves the algorithm stinks lol

    • @smitbangare9526
      @smitbangare9526 Месяц назад +1

      Same 🤣

    • @QuackerJack09
      @QuackerJack09 20 дней назад +1

      same :D

    • @Verchiel_
      @Verchiel_ 14 дней назад

      @@TheeUnpleasantPeasant algorithm doesn't just throw exactly the videos you've watched at all times
      It always experiments throwing stuff you might never have watched. I often get small obscure videos in the tens or hundreds of views.

  • @TonyWhitley
    @TonyWhitley Месяц назад +58

    Brings back memories of when we first realised phones were vulnerable to hacking. First we added thousands of null pointer checks then later used fuzzing to uncover hundreds of less blatant vulnerabilities. It was In the order of a year's work for hundreds of developers and testers. One of my contributions was to make it possible to test the code off target, up to that point all testing was running the complete phone on an emulator or even an actual phone against test equipment.

  • @WHYUNODYLAN
    @WHYUNODYLAN Месяц назад +205

    4:09 ermmm...its the GNU Compiler Collection, akshually

    • @LowLevelTV
      @LowLevelTV  Месяц назад +95

      AKSHUALLY

    • @tcscomment
      @tcscomment Месяц назад +7

      didn't they just rename it? IIRC GCC used to be a compiler for a lot of languages, now it supports like 4

    • @Brahvim
      @Brahvim Месяц назад +11

      Also, "G-N-U" instead of "Gnoo".

    • @SomebodyHere-cm8dj
      @SomebodyHere-cm8dj Месяц назад +2

      no? unless it was retroactively added(which is possible), even versions ​from 1999 call it "GNU Compiler Collection" @@tcscomment

    • @tcscomment
      @tcscomment Месяц назад +1

      @@SomebodyHere-cm8dj I honestly have no idea.

  • @Masmikh
    @Masmikh Месяц назад +125

    What am I doing here.

    • @Power-Wiesel
      @Power-Wiesel Месяц назад +10

      I like turtles

    • @pjodron
      @pjodron Месяц назад +12

      i ask that myself everyday i wake up.

    • @kevinsedwards
      @kevinsedwards Месяц назад +1

      Aliens are real

    • @StkyDkNMeBlz
      @StkyDkNMeBlz 24 дня назад +1

      I don't belong here

    • @5371W
      @5371W 22 дня назад +1

      I don't care if it hurts.

  • @RichardEricCollins
    @RichardEricCollins Месяц назад +158

    That template code was common in the 80's and 90's when compilers were bad at optimizing code. I expect this code was first written on 486 type systems where every cycle counts.

    • @thedeemon
      @thedeemon Месяц назад +18

      Actually Zstd was created rather recently (~2016) at Facebook

    • @jsrodman
      @jsrodman Месяц назад +13

      Nope, 7zip is much newer than that, and zstd even newer.

    • @coyo_t
      @coyo_t Месяц назад +54

      @@jsrodman just because the program is newer doesnt mean the programmer isnt
      old habits die hard (and can be passed down)

    • @rlube01
      @rlube01 Месяц назад +4

      When you want a fast code execution sometimes you do define trick, some compilers has a good optimization but they does not know what you really want to do so some times you still need to do this trick for code acceleration

    • @jeffrey1312
      @jeffrey1312 Месяц назад +4

      Maybe a very poor attempt at optimization. Pretty much every compiler can out optimize a human these days. If this had been written on a PDP-11 in 1975 when compilers were stupid it could maybe be justified.

  • @olokelo
    @olokelo Месяц назад +251

    So it's a bug in ZStandard implementation, not the 7-zip (LZMA). The ZStandard is not 20 years old btw and 7-zip doesn't have any proprietary codecs from what I remember.

    • @LowLevelTV
      @LowLevelTV  Месяц назад +112

      yeah its a bug in their implementation of 7zip, not the Zstd spec.

    • @XenoCrimson-uv8uz
      @XenoCrimson-uv8uz Месяц назад +67

      @LowLevelTV I am confused, you agree and say the opposite?
      You agree that its a bug in Zstd implementation not in 7-zip, then say its a bug in 7zip?

    • @ddg-norysq1464
      @ddg-norysq1464 Месяц назад +2

      @@XenoCrimson-uv8uz i think he agreed with the no proprietary codecs?

    • @destiny_02
      @destiny_02 Месяц назад

      ​@@XenoCrimson-uv8uz7zip is a archiver program that supports many compression techniques. But 7zip is also the name of the file format that stores LZMA compressed data.
      what he's saying is that the bug is in the 7zip archiver's implementation of zstd, not in the 7zip file format (LZMA) or in the zstd algorithm itself.

    • @samjiman
      @samjiman Месяц назад +83

      @@XenoCrimson-uv8uz He means it's a bug in 7-Zip's implementation of Zstd rather than the Zstd spec itself.

  • @nickwallette6201
    @nickwallette6201 Месяц назад +29

    That "impossible to read code" reminds me of my recent adventure in trying to understand file compression by writing my own deflate implementation. I'm not a mathematician, not a number-theory type at all, and this stuff does my head in. I also usually have to read a minimum of like three or four different explanations of an algorithm to even begin to understand how it works, because most of them are written by people who do understand them, and our brains do not share much space in that particular Venn Diagram, so their explanations make no sense to me at all.

    • @alx9r
      @alx9r 13 дней назад

      @@nickwallette6201 I have the other brain, apparently. I low-key found the assertion that “this code is unreadable” offensive. Judging readability of code whose purpose you are unfamiliar with is either arrogant or ignorant.
      That code might be perfectly readable to those who are skilled and familiar with the domain, that is, those who maintain the code. I couldn’t judge in this case because I don’t know either compression or the compilers they are targeting well enough, but there’s also nothing that stands out as indicating that it’s “unreadable.”
      I found the guy in the video’s arguments for why it’s “unreadable” completely unpersuasive. He’s just casting aspersions for no apparent reason.

  • @DaganMcGregor
    @DaganMcGregor Месяц назад +28

    I thought this was a new CVE. This is something that was fixed in 7zip months ago. I am already on a version above the one mentioned containing the fix

  • @Ariccio123
    @Ariccio123 Месяц назад +25

    6:55 the reason they're doing that there is in the name - it's hand optimized to enable vectorization!

  • @insu_na
    @insu_na Месяц назад +81

    len doesn't have to be 0 to cause a crash, it just needs to not be a multiple of COPY_CHUNK_SIZE, right?

    • @OhhCrapGuy
      @OhhCrapGuy Месяц назад +15

      Exactly right, as far as I can see, I thought the same thing.
      That's one of the things I learned early on, never loop down to x == 0, loop down to x

    • @kuhluhOG
      @kuhluhOG Месяц назад +1

      yes, but I don't think you can exploit it then since you would have an infinite loop

    • @deltamico
      @deltamico Месяц назад +4

      Not infinite, there just needs to exist q such that len=q*chunk_size mod int_range or whatever type they using. Nvm, that can occur only if chunk_size is not a power of 2 which it probably is

    • @gideonsiete1868
      @gideonsiete1868 17 дней назад

      @@OhhCrapGuy Correct.

  • @danielpetersen2147
    @danielpetersen2147 Месяц назад +27

    Correct me if I'm wrong, but the vuln, and the repo you visited, are for a fork of 7zip modified by mcmilk to include the zstd algorithm, because 7zip's original author declined to include it. If so, 7zip's creator may appreciate some clarification here.

    • @LiveWireBT
      @LiveWireBT Месяц назад +6

      He really would.
      But he's Russian, so that's out of the question for American fascists.
      To me the name on mcmilk's page reads German. That completely destroys the anti-russian sentiment, but it doesn't stop the crowd here.
      I'm German too by the way, so no hard feelings. Talk is cheap every Open Source maintainer is thankful for support and PRs.

    • @jonah1976
      @jonah1976 Месяц назад +1

      @LiveWireBT OK, Lennart.

    • @Luxalpa
      @Luxalpa Месяц назад +11

      @@LiveWireBT Russia is loved by American fascists though.

    • @AgentOffice
      @AgentOffice Месяц назад +8

      @@LiveWireBT the fascists do love Russia tho lol

  • @maartenofbelgium
    @maartenofbelgium Месяц назад +14

    2:37 `const Byte ptr` is an unsigned byte (8 bits), `const unsigned sym` is an unsigned int (32-bits)

  • @robcarnaroli269
    @robcarnaroli269 Месяц назад +16

    I've been in IT for more than 2 decades and still get blown away by this level of security analysis.

    • @edwardmacnab354
      @edwardmacnab354 Месяц назад

      yeah he's pretty impressive . Does anybody know what his actual job is , or was ?

    • @sammxn-w2v
      @sammxn-w2v Месяц назад +4

      this type of analysis doesn't fall under the umbrella of IT (information technology), it's cybersecurity and reverse engineering which is a different field entirely

    • @edwardmacnab354
      @edwardmacnab354 Месяц назад

      @@sammxn-w2v I'd rather my IT staff had this level of expertise rather than just be capable of configuring a server

    • @nameq
      @nameq Месяц назад

      @@sammxn-w2v cyber security also known as IT security most definitely falls under IT

    • @nameq
      @nameq Месяц назад

      @@sammxn-w2v so does reverse engineering specifically reverse engineering of computer programs the very thing he does. how is either of them not IT?

  • @lephtovermeet
    @lephtovermeet 21 день назад +5

    I've been waiting for 8zip to drop for decades

  • @sanjaycse9608
    @sanjaycse9608 Месяц назад +108

    3:46 Obfuscation by programmer

    • @klbk
      @klbk Месяц назад +8

      truest, most efficient security measure

    • @robertnagy3942
      @robertnagy3942 Месяц назад

      @@sanjaycse9608 me when I name my Java custom named query Journal.query and then place it in the publisher class

  • @nathantron
    @nathantron Месяц назад +23

    You should make a video on all of the tools that people can use to FIND easy to fix bugs, and vulnerabilities in their own projects. Like a "Fix Your Shit Toolkit" that gives you tons of useful things they can run against their own stuff like you just did here.

  • @OhNotThat
    @OhNotThat 21 день назад +2

    The beauty of open source software is that the whole premise of many hands make light work and many eyeballs spot flaws and bugs faster is that by scrutinizing and finding problems with it you're actually making it safer and better. While indeed almost all open source projects are maintained by 1 or 2 guys, writing all of the code this is true for almost all software projects. Unlike closed source though, you're welcome to check and improve their work. Just because closed source is "Secret" it doesn't make it any more secure because at the end of the day, the compiled executable code is 100% visible to tinker with and there are very talented reverse engineers who can quickly pick it apart. Look at how DRM gets defeated and how much lengths even Denuvo must go to to try and encrypt the actual machine code haha!

  • @byAnArgentinian
    @byAnArgentinian Месяц назад +34

    7 zip is an awesome utility, tho. For a basic windows user it may be one of the easiest way of reading folders hidden by malware and stuff like that, even when it seems impossible from basic cmd commands.

    • @JimmyCerra
      @JimmyCerra Месяц назад +3

      @@byAnArgentinian eh, I stopped using 7zip because of all the security vulnerabilities that took a long time to patch. Their code isn’t very good, as this video demonstrates.

    •  Месяц назад

      How do you read malware hidden files in 7zip ? By just exploring a directory with the 7zip binary ?

    • @byAnArgentinian
      @byAnArgentinian Месяц назад +9

      The built explorer of 7zip shows (well) hidden folders and files under Windows as if you were using linux

    • @uspecl
      @uspecl Месяц назад

      what folders are still hidden after you enable showing hidden files/folders in the file explorer settings?

    • @byAnArgentinian
      @byAnArgentinian Месяц назад +5

      @declspecl oh believe me there's WAY more than that lol

  • @gaius_enceladus
    @gaius_enceladus Месяц назад +11

    Interesting to see this video.
    I've used 7-zip many times and have found it to be very good. Never had any problems.
    Having said that, I wouldn't know a code vulnerability if one walked up to me with a flashing neon sign saying "I'M A CODE VULNERABILITY".

    • @andrewz4718
      @andrewz4718 Месяц назад +4

      Yeah the title was a bit of click bait. The code is hard to understand but its efficient and runs well and was patched. It would have to be a malicious archive to cause all those crashes.

  • @maxheadrom3088
    @maxheadrom3088 Месяц назад +9

    7-zip is awesome. Didn't know it's just two people!

  • @polinskitom2277
    @polinskitom2277 Месяц назад +96

    I wish Igor would implement recovery records like Rar does. I still have to use Rar on linux for that purpose (and for work, but I digress), and it's sad to see that 7-zip still is stuck in 2007 on this issue. People actually care about archiving their data, and whenever they find out that 7-zip eats its own header data randomly on file creation and have no clue how to recover their family photos/emails, etc, always breaks my heart. This is never an issue on Rar or standard ZIP/Tar creations, and it shouldn't be on 7-zip

    • @JohnSmith-vd8nn
      @JohnSmith-vd8nn Месяц назад +14

      I'm not familiar with this 7zip issue. Would you please expand on it?

    • @rogo7330
      @rogo7330 Месяц назад +12

      Emm, ZIP literally puts the main header at the end of the ZIP-file just because it's easier to overwrite it when you add more files to it. If your file system failing to safely crash, and if RAR does not creates a copy of the file before editing it and then renaming it over the old one once it's done creating it, nothing will help you, because file is gone from your file system. Also, just use tar to archive photos, or zip with no compression disabled. If you want to store in the same archive something very compressable (like plain-text documents), then that's very not efficient, because if you put everything in the tar (that does not do any compression, it's just a bunch of blocks 512-bytes each with just headers and data in them) and then compress everything with xz (lzma, the same as 7-z) or gzip (exists everywhere, including web), you'll get more compression out of it because compressor (xz, gzip) will compress all of the tar archive ("archive" is just a bunch of files stored more closely to each other than on the file system, because file systems, usually, store each file in chunks of 4 kb each, usually, for optimizations reasons), not each file individually.

    • @polinskitom2277
      @polinskitom2277 Месяц назад +37

      @@JohnSmith-vd8nn if a single bit of data bitflips (I.E, 1 becomes 0 because of hardware degradation anywhere in the archive) on 7zip, you have no chance of recovery nor any chance of extracting because it's one long stream. Rar on the other hand, with no recovery record, will just skip the file affected and extract everything else. Rar with a 5% recovery record, will go right ahead and fix the bitflip, and will extract everything just like it was

    • @polinskitom2277
      @polinskitom2277 Месяц назад +12

      @@JohnSmith-vd8nn the 'eating header data' part is mostly seen in enterprise environments. I have seen this issue firsthand at work, which caused us to switch from 7zip to RAR and gzipped tarballs, but I know some friends of friends who have said they had that issue too, and friends of those friends' friends, and etc, so not an entirely isolated incident

    • @DriftJunkie
      @DriftJunkie Месяц назад

      Just stop using 7zip for visual media

  • @johnrushing1540
    @johnrushing1540 Месяц назад +5

    My guess is that the macros are used for speed reasons. They avoid the overhead of a function call, and were commonly used in speed critical code before compilers could reliably use inline to do the same thing. We used to do this back when I learned C in the 80's but I doubt that many people do it now since it makes the code far less readable.

  • @BWilks
    @BWilks Месяц назад +10

    @55s - puzzling claim that 7z is proprietary. you should have corrected that error on sight instead of repeating it ;-p 7z format is public domain. that's freer (sic) than open source!

  • @JohnDlugosz
    @JohnDlugosz Месяц назад +19

    7:00 Why do Macro Programming? Because when the project was first written, C didn't have _inline_ functions and the compiler didn't just inline stuff on its own.

    • @9a3eedi
      @9a3eedi 5 дней назад

      Even with inline functions there's no guarantee that the compiler will inline the code. Macro programming on the other hand guarantees it.

  • @Mmouse_
    @Mmouse_ Месяц назад +15

    I've been out of the loop for a long, long time... But you can fuzz like that now?! That's insane... And also, scary and awesome.

    • @futuza
      @futuza Месяц назад +2

      Yeah this made me feel ipd and outdated

    • @complexity5545
      @complexity5545 Месяц назад

      Yeah its been like this since about 2012. I daily fuzz ^^ [ pen test] my own applications just to see vulnerabilities. Kali Linux is invaluable since about 2013. That's when everything computer software, for me, got easy: kali linux is my daily driver. I remember before kali, I had to actually scrape the forums, android sites, hackintosh sites, freebsd forums, archlinux sites, torrents, and talk to white hatters to find information that would give me a glimpse or name of some dungeon program. That all ended with kali + github + youtube + twitter. That and search github for fuzzers and analyzing programs and plugins. It literally takes like 30 minutes or less to find exploits with the right hardware.

  • @kenworks6068
    @kenworks6068 Месяц назад +3

    I'm not a good programmer but I learned a lot by following and understanding your process flow. Very well presented.

  • @emerjay348
    @emerjay348 Месяц назад +37

    Having ads in browser as a cyber security channel is crazy

    • @AsdAsd-n6u
      @AsdAsd-n6u 19 дней назад +1

      Why? Do ads bring security issues?
      I've thought they are just annoying.

    • @emerjay348
      @emerjay348 19 дней назад +8

      @@AsdAsd-n6u Yes, blocking javascript in different websites is crucial

    • @shotnothing3419
      @shotnothing3419 15 дней назад +1

      @@emerjay348 why don't browsers do this by default then?

    • @Nick2bad4u
      @Nick2bad4u 15 дней назад

      Most do ​@@shotnothing3419

    • @thelogicmatrix
      @thelogicmatrix 15 дней назад

      @@shotnothing3419 user experience, removing JavaScript can break websites

  • @tikabass
    @tikabass Месяц назад +6

    @2:36: The difference between Byte and unsigned. In the 7zip realm, Byte is an unsigned char (8 bits wide), unsigned is an unsigned int (32-bits wide, on x86-64). The change of width does not really affect outcome, since the overflow is checked by the inserted lines 1313 & 1314 (the actual bug fix). The type change is probably done so that the test at line 1313 is done on two variables of the same width, to avoid a compiler warning.

    • @0xhhhhff
      @0xhhhhff Месяц назад

      So the location he said the bug is, isn't actually where it is?

    • @tikabass
      @tikabass Месяц назад +2

      @@0xhhhhff 7zip has acquired a spaghetti-like structure throughout the years. I haven't read all of the diffs in the code, but it's likely that similar boundary checks were added in as many as a dozen (or two dozens) similar loops in the code.

    • @tikabass
      @tikabass Месяц назад

      @@0xhhhhff I have to say that I do have an issue with his explanation @11:05. If you and pause @6:57, you'll see the whole code, that is COPY_PREPARE, COPY_CHUNK, and CopyLiterals(). The two commented lines above CopyLiterals() are the contract: len != 0 and len

  • @SunsetGraffiti
    @SunsetGraffiti Месяц назад +1

    Love this story format, man~~ I also love when you're excited to share stuff. When you're excited, I'm excited.

  • @xanaxity
    @xanaxity Месяц назад +118

    Every. CVE. is. Not. RCE. 😭

    • @EvilGPT
      @EvilGPT Месяц назад +11

      ​@@xanaxity but every RCE can be a CVE

    • @xanaxity
      @xanaxity Месяц назад +7

      @@EvilGPT Nowadays, with user level utilities (like 7z) RCE is always a chain of CVEs.

    • @tofu6119
      @tofu6119 Месяц назад

      Oh yehhhhh

    • @jacobstamm
      @jacobstamm Месяц назад +2

      @@xanaxity “every CVE is not RCE” means “no CVE is RCE”. What you meant was “not every CVE is RCE”.

    • @xanaxity
      @xanaxity Месяц назад

      @@jacobstamm Oh I mean, people tend to shift the conversation to "Can we get a RCE out of this?" when the CVE has base CVSS score of like 7 or below. It's kinda weird, I don't see it that way, RCE shouldn't be a goal imo, you can cause DOS or do serious damage, that should be a concern.

  • @russellzauner
    @russellzauner Месяц назад +1

    if you haven't done an episode lately on code browsers and browsing/browser features...always nice for a refresh.
    EDIT: also, GREAT video on not just instrumenting your code but what it's for. It's stuff like that tells me I'm subbed to the right channel. If you want to go deeper, if you haven't talked about generating symbol files for use with trace/logic analyzers, that's pretty amazing stuff - especially for people just starting, very visual demonstration of the internals in process of embedded debug/test. It becomes even more useful in test/validation automation ;-) thanks again for spending your time putting up nice videos that teach people actual skills and thought processes behind them.

  • @ulincsys
    @ulincsys Месяц назад +4

    In this context, I think "integer underflow" is not quite the correct term for the title of the CVE. Any integer operation that would lead to "wrapping around" would be considered overflow, regardless of in what direction you're going. Generally, "underflow" is a term reserved for inaccuracies in floating-point operations.

    • @kc5402
      @kc5402 Месяц назад

      Correct.

  • @joehopfield
    @joehopfield 25 дней назад +1

    I started using adb, then gdb, 45 years ago on V7 then first gen BSD. With the incredible power of modern software dev tools, it's somehow heartwarming that gdb still matters... that said, the entire sequence you use seems like it should be used before any production software is released.

  • @aqueousdog
    @aqueousdog Месяц назад +4

    Thank you for the reminder to update 7zip

  • @randomdodads
    @randomdodads Месяц назад

    As a coder for more than 25 years I am truly impressed abt what you are doing!

  • @DmkaOz
    @DmkaOz Месяц назад +20

    7zio ZStandard is not an offical 7zip product but instead a modified version of 7zip to support additional archive formats such as ZStd, LZ4, LZ5, Lizard.

    • @ytxzw
      @ytxzw Месяц назад +2

      7zip recently added native support for decompression at least, I'm not sure which one is referred here in the video

    • @nickplays2022
      @nickplays2022 Месяц назад

      @@ytxzwthe one from the GitHub at 2:02

    • @TheStolenBattenberg
      @TheStolenBattenberg Месяц назад +4

      I thought that was the case. Gotta love the claim of 1000’s of crashes too, I’ve used 7zip for probably 15 years and think I’ve only encountered one or two while doing other things and leaving it extracting in the background

    • @ishallah917
      @ishallah917 Месяц назад +1

      He's talking about main 7-Zip. The 7-Zip Standard fork have different implementation of Zstd which is not affected by this CVE. 7-Zip only supports decompression and had the CVE

    • @privateger
      @privateger Месяц назад

      @@TheStolenBattenberg Yes, and you aren't throwing billions of purposefully corrupted inputs at it.
      Of course you don't encounter those crashes.

  • @benoithudson7235
    @benoithudson7235 Месяц назад +3

    Old code has lots of macros because back in the day, you couldn’t trust the compiler to actually inline. So everyone had to know how to write macros and used them extensively. So they got used in ways that were terrible ideas.

  • @ScottHess
    @ScottHess Месяц назад +4

    Heavy use of macros is generally because compilers weren't always great, and you found profiling results which indicated that there was performance to be had. So you rewrote things using macros to get that delicious inline code. Unfortunately, macros are sticky, you generally won't later get profiling results which tell you that your compiler can now do all that for you, because the non-macro code paths no longer exist and the profiler doesn't see macros. For the MOST part, people don't go crazy with C macros just on a whim.

  • @j7ndominica051
    @j7ndominica051 Месяц назад +2

    7-Zip added a zstd decoder recently. It's not 20 years old. The author wanted to write it on his own rather than use a library, and couldn't yet make an encoder.

  • @IAmPaigeAT
    @IAmPaigeAT Месяц назад +3

    If you look at the preprocessed code, the macros should expand to the code they're defined with anywhere you use them, the idea is that its like making a function call without having to actually make a function call so it doesn't have to allocate a stack frame and all that shit but whether or not it makes any sense to do that depends on how often the code is being ran and it probably makes les sense to do that on modern computers, I think nowadays the preferred way to do this is to use the inline keyword

    • @eshark11
      @eshark11 Месяц назад

      Some language compilers will optimize and inline automatically. For example C# can do this.

  • @VGMinds
    @VGMinds Месяц назад

    I love your videos, everytime I realise how MUCH I still don't know. It's just amazing.

  • @ethangreer1362
    @ethangreer1362 Месяц назад +1

    If ever you encounter a PySR generated structure... You will never forget it. It is like a code from the year 3000. A must if you haven't seen it. It is beyond human.

  • @hassansyed5661
    @hassansyed5661 Месяц назад +2

    In the past, Winrar had a similar issue and with the help of it an attacker can execute his program directly

  • @ilgar.roshen
    @ilgar.roshen Месяц назад

    Watching the channel more than a year. Worth subscribing !

  • @arthurmoore9488
    @arthurmoore9488 Месяц назад +8

    My personal bet is there isn't an exploit. It's not "good", but the CVE system has thoroughly proven itself to be unreliable.

  • @justinklein7071
    @justinklein7071 21 день назад

    I just found your channel from my algorithm and this was such a great video! You do an amazing job explaining things and I will be subbing!

  • @floatingblaze8405
    @floatingblaze8405 Месяц назад +5

    3:24 "I was realizing that this code is impossible to read"
    Dear gods, Silicon Valley season 2 was right when the Dinesh and Gilfoyle tried to make sense of the original compression library code without the help of Richard XD

  • @markcbaker
    @markcbaker Месяц назад +2

    Where I used to work, 7-zip was on all our windows laptops. It was widely used to extract packages of logs that were zip’s, cpio’s, tgz’s, and xz’s within zips.

    • @ytxzw
      @ytxzw Месяц назад +4

      it is just the best..

  • @coreybrenner
    @coreybrenner Месяц назад +5

    @11:20 "len" does not have to start out at 0, to allow this bug to overwrite unintended memory. It is sufficient for that variables value to be less-than COPY_CHUNK_SIZE.

    • @snygg1993
      @snygg1993 Месяц назад +3

      not divisible by COPY_CHUNK_SIZE
      However, I'm not sure if that would be exploitable, because you somehow have to leave this infinite loop eventually.

    • @mattrogers6646
      @mattrogers6646 Месяц назад +1

      ​@@snygg1993Correct. I think you could only leave the infinite loop if COPY_CHUNK_SIZE was not a power of 2.

    • @snygg1993
      @snygg1993 Месяц назад +2

      @@mattrogers6646 It might still take "a few" overflows until you eventually hit zero 😁

  • @freecalradia
    @freecalradia Месяц назад +1

    I play your videos for gaining knowledge, i stay for the backgroundnoise/ white noise that they become when i eventually lost the track. My sleeping quality imrpoved.

  • @pu239
    @pu239 Месяц назад +12

    12:35 It's winget update to you! lol

  • @user-dv5gm2gc3u
    @user-dv5gm2gc3u 21 день назад

    algorithmic code is always hard to understand. First you must understand the algo, next the code and the tricks are used, and after that you might be able to understand it and change things. Even for the developer itself it's hard to understand when revisiting the code after a while.
    Same is true for graphics engines, or even small javascript-animations.
    Cool video showing about using c, fuzzing & the debugger!

  • @KiraSlith
    @KiraSlith Месяц назад +4

    You're so clean, succinct, and clear as a narrator. It'd be amazing if you did a tutorial series on learning to use some of these tools like the fuzzer, something to teach developers how to be their own red team?

  • @Soviet_Elmo
    @Soviet_Elmo Месяц назад

    Such a nice and cool demonstration. I speak a very tiny bit of C based languages, but I still got an idea what was going on. Thanks!

  • @philipmrch8326
    @philipmrch8326 Месяц назад +5

    It's always a missing length check before memcpy

  • @notorious_turtle
    @notorious_turtle Месяц назад +2

    ZDI only pay for exploitable bugs, so the person who found this would have been able to exploit this or at the least show control of execution flow. Great video!

  • @animuspexus
    @animuspexus Месяц назад +5

    1:10 - since when 7z is proprietary?

  • @lockaltube
    @lockaltube Месяц назад +1

    The biggest question was not asked - why do they *use their own zstd decompressor?* Why they rewrite decompressors of initially open-source standards, instead of using libraries that were extensively fuzzy-tested? Yes, 20 years ago it was fine - many libraries were not portable, not optimized or not opensource (like RAR), but why now?

  • @T1Oracle
    @T1Oracle Месяц назад +28

    There's nothing I dislike more than trying to parse someone else's badly written code 😫

    • @Mario583a
      @Mario583a Месяц назад +2

      "this is bad, dumb code, and more importantly it's bad dumb code that doesn't make any sense here" ~~ Valve employee Kyle on TF2's code.

    • @kristoffer8609
      @kristoffer8609 Месяц назад +6

      Let's be fair though, just because you can't read someone else's code doesn't mean it's badly written. You could also just be dumb.

  • @NunoSilva-rb6mh
    @NunoSilva-rb6mh Месяц назад

    One of your best videos, very informative.
    Good job!

  • @eduardogoncalves3031
    @eduardogoncalves3031 Месяц назад +5

    wait, 7Zip is a mess? I thought it was the best compress/decompress tool

  • @Baile_an_Locha
    @Baile_an_Locha 24 дня назад

    Many of the most widely used open source projects are riddled with places where signed integer variables are used to hold values than can never legitimately be negative. The real surprise for me is that vulnerabilities like this aren’t found more frequently.

  • @ZSec-ei4bv
    @ZSec-ei4bv Месяц назад +16

    if you're worried about macro programming, take a look at QEMU's object model. It's a giant mess, I can't whitstand C anymore

    • @lolilollolilol7773
      @lolilollolilol7773 Месяц назад +2

      Zig for the rescue ! Or Rust.

    • @ZSec-ei4bv
      @ZSec-ei4bv Месяц назад

      @lolilollolilol7773 zig does not enforce safe code unfortunately

    • @Mr-Sinister
      @Mr-Sinister Месяц назад +1

      @@lolilollolilol7773 i'd rather Zig.

    • @nnshshwh3966
      @nnshshwh3966 Месяц назад +4

      @@lolilollolilol7773 Rust FTW

    • @ZSec-ei4bv
      @ZSec-ei4bv Месяц назад

      @@lolilollolilol7773 zig does not enforce safety

  • @Fordmet
    @Fordmet 9 дней назад +1

    after seeing the code for 7zip in this video. I now understand why Winrar decided to make the 30 day trial never expire

  • @spudhead169
    @spudhead169 25 дней назад +4

    I could follow that fine just from the brief view you gave on screen. Nothing wrong with it. You have some serious snob issues if you think you need to verbose name a temp loop variable or limited scope variable that does not span a page. From what I can see, that code is perfectly readable.

  • @pedrobuss1
    @pedrobuss1 Месяц назад

    Danm, docker sponsoring you? For me this is on another level

  • @WeatheRay
    @WeatheRay Месяц назад +5

    I learned more watching this in 6 min that I did in 4 years as a "security engineer"
    Really helps to have people teach instead of hide information from you..

  • @diegolikescode
    @diegolikescode Месяц назад

    Your channel is called low level, but it is one of the highest level of content on this platform

  • @fang64
    @fang64 Месяц назад +5

    Do we know if p7zip package contains this vulnerability?

    • @leonardosoteldo9542
      @leonardosoteldo9542 Месяц назад

      It seems it wasn't affected, as the code was not present. Look for it in the Debian security tracker (CVE-2024-11477). The stable 7zip was not affected neither because the bug was introduced in v24.01 and the Debian stable package currently uses 22.01. LMAO and it really shows that stable is actually better for security concerns (older versions with known bugs are also patched for security reasons when needed.)

    • @edelzocker8169
      @edelzocker8169 Месяц назад

      No

  • @Gastell0
    @Gastell0 Месяц назад +2

    What's odd is that they called it an RCE, while it's not directly an RCE, as 7-Zip itself does not interact with network in any way by itself to be directly exploitable, and there's no known software that is vulnerable because of it

    • @nm_9_
      @nm_9_ Месяц назад +1

      True and i’m not sure how this could be used in practice so I think it is a nothing burger

    • @VidarrKerr
      @VidarrKerr Месяц назад

      WWIV will be over before someone gets hacked by 7zip.

  • @lonestarseoul
    @lonestarseoul 22 дня назад +3

    I like your funny words magic coding man

  • @ShiroKage009
    @ShiroKage009 23 дня назад

    This can't be just maintained by just 2 people. This needs to be a much bigger project with a much bigger crowd. Like holy crap.

  • @GilesBathgate
    @GilesBathgate Месяц назад +6

    I always like a good vulnerable code bath. 4:55

  • @BinaryAdventure
    @BinaryAdventure Месяц назад

    This exact video was my life for a few years as a product security incident response analyst.

  • @pac-d6f
    @pac-d6f Месяц назад +6

    Does this affect Zstd as well?
    Or was 7zip using their own implementation?
    Zstd would be a very big target, like Xz.

    • @LowLevelTV
      @LowLevelTV  Месяц назад +11

      nope not the Zstd spec, just their implementation of Zstd.

    • @rogo7330
      @rogo7330 Месяц назад +2

      @@LowLevelTV where are they get it though? Wrote entierly from scratch? Because if this bug exists somewhere else, like in libzstd, then we're in a big trouble. Arch, for example, opted in to compress everything with this algorithm in the mainline repo. I bet many distros done this as well.

    • @ennio5763
      @ennio5763 Месяц назад

      @@rogo7330 It's a bug in the zstd decoder implementation of 7zip, which was written from scratch by Igor Pavlov.
      It's unrelated to libzstd.

    • @mattrogers6646
      @mattrogers6646 Месяц назад +2

      @@rogo7330 Yes, Igor Pavlov wrote the Zstd implementation used in 7zip himself, for whatever reason. So other Zstd implementations that are done to spec aren't affected.

    • @Daniel15au
      @Daniel15au Месяц назад +1

      The reference implementation of zstd has already been security audited as far as I know. The comments at the top of 7-zip's implementation say that it was written based on the spec. It doesn't use any of the code from the reference implementation.

  • @jamescooper6334
    @jamescooper6334 8 дней назад +2

    Of all the criticisms, you are complaining about names like "src" and "inSize"? These are very common names in programming that are intuitive and unambiguous when talking about processing the contents of a file. I agree that "b0" and "b1" are not good names, but the examples you used are completely reasonable. What would you consider a minimum acceptable variable name?

  • @LeetHaxington
    @LeetHaxington Месяц назад +4

    There's an absolute massive ton of programs that bundle their own portable version of 7zip along with the rest of the program. Sometimes there's even multiple nested bundles of 7zip. So presumably all of those would need to be patched too, which is never going to happen.

    • @sharp14x
      @sharp14x Месяц назад +2

      Which typically run once, and only on their own data. The only thing that could interfere with that is a program already running on a system or a user, which could do the same things anyway.

    • @edelzocker8169
      @edelzocker8169 Месяц назад

      you mean a "UnZipMe.exe"?

  • @hattmarvey1989
    @hattmarvey1989 Месяц назад

    (Macros are often used because it saves the overhead of the stack push and function call. It runs significantly faster if it's called millions of times. But it's only useful if the macro is used in many places, if used in only one place then it makes no sense. )

  • @legionary000
    @legionary000 Месяц назад +7

    8:22 - I'm sorry but I was just exploding out of laughter on that xD TRRRRRRRRRRRRR
    Its interesting how we take softwares available to everyone as "suppose to work, no harm" for granted.

  • @thevikas5743
    @thevikas5743 Месяц назад

    Was surprised when you recreated the context using crash file and gdb. the crash file is same as core dumped? That is superb. Never seen a way to recreate a crash context in any "modern/high level languages". We just simulate it in our head. I mostly do php, js and little C++. And debugging tools in these is garbage.

  • @sinom
    @sinom Месяц назад +8

    "typically when you compile code you use this thing called GCC"... Or msvc or clang and only specifically when compiling C or C++ code

  • @SpotTiger
    @SpotTiger Месяц назад

    I understood nothing about this, but I support your enthusiasm!

  • @lukasbeyer2649
    @lukasbeyer2649 Месяц назад +7

    docker sponsors youtubers? damn

    • @hellcoreproductions
      @hellcoreproductions Месяц назад

      I'm conditioned to sponsors basically being malware, I'm not sure how to respond now.

    • @nagorik24
      @nagorik24 25 дней назад

      @@hellcoreproductions lol

  • @robertbowman2920
    @robertbowman2920 Месяц назад +2

    Looks like the COPY_CHUNKS macro needs to defensively check for less than zero rather than assume the len var will land at zero (false), just in case the buffer size isn't divisible by CHUNKSIZE. Big assumption in COPY_CHUNKS that it is given a matching buffer and chunksize. However, maybe the COPY_PREPARE macro is doing that check and setting len to something appropriate, a bit hard to read ...

    • @eshark11
      @eshark11 Месяц назад

      This quirk of C that you can treat an integer as a boolean, in an 'if' test, has resulted in other bugs than this one. Why not just test exolicitly for > 0 e.g. while ((len -= COPY_CHUNK_SIZE) > 0) and avoid possibility of going past the boundary. By more than part of one chunk size.