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Show HN: Ezcrypt – A file encryption tool (simple, strong, public domain)
- forty 2y agoThis seem to use home made cryptography, which is never a good idea. In particular it's not clear why this design with layered algorithms is needed, nor why it uses a non standard KDF. Prefer using libsodium for the crypto, which has made sensible choices for you.
- forty 2y agoAlso you are missing a MAC, which is also a bad idea
- deknos 2y agowhat does this provide which cannot be done with openssl, which is available for most systems?
- cynicalsecurity 2y agoOpenSSL should not be used for encryption of files. PGP/GnuPG should.
- max_ 2y agoWhy not?
- tptacek 2y agoLast I checked, there's no authenticated encryption option in the OpenSSL CLI.
- tptacek 2y agoNo, PGP isn't much better.
- stackghost 2y agoGnuPG and PGP are a shit show. Just make an encrypted drive volume instead.
- SahAssar 2y agoHow would you compare this to existing tools in the space like https://github.com/FiloSottile/age https://github.com/FiloSottile/age? Seems like age has multiple implementations (rust, go), has a permissive license, a public specification (https://github.com/C2SP/C2SP/blob/main/age.md https://github.com/C2SP/C2SP/blob/main/age.md) and the spec/core implementation is developed by someone with a history with cryptography (I don't know if you do, but there is no indication or name attached to the repo). While many things can be built as a hobby or learning project I feel like cryptography is one of those spaces where you should be clear if it is that and if it is not you need to expressively argue its bona fides up front.
- ezcrypt 2y agoage is definitely more mature, and as you say, it should probably say somewhere that ezcrypt is still a hobby project (albeit a serious one). Some motives (some of which may sound strange, but mattered to me): * Completely public domain. * Without any third party dependencies (not even openssl or similar). * Don't rely on a single cipher (low trust). * Extremely portable (should easily build for and run on anything from an M4 Mac to a Raspberry Pi to an old OpenWRT MIPS router with 32 MB RAM for instance). * Should be easy to use (e.g. no key management, unless you want to), and composable in standard Unix ways (pipes etc). * Security focused, obviously. E.g. software architecture-wise, minimize dependencies, properly manage files, processes and secrets, etc. * Personally: To learn and to build something that I trust. In a way: When the dust settles after the nuclear apocalypse, if you manage to dig out a C compiler, this is your tool. ;-)
- tptacek 2y ago"Don't rely on a single cipher" is an anti-goal, and a reason your hobby project won't be taken seriously. You'd be better off striking it from the list. "Zero dependencies" is also not especially reassuring, as it implies you're using your own cipher implementations (or reference implementations).
- shanusmagnus 2y ago
- voodooEntity 2y agoI recently gave building a file encryption tool a shot myself ( https://github.com/voodooEntity/go-tachicrypt https://github.com/voodooEntity/go-tachicrypt ) tho i didnt implement my own crypto to be fair. I think its always good to dive into topics if you are actually interested and lets face it, the beginning of most of the big things nowadays started somewhere in a basement or a garage.
- tptacek 2y agoThe code isn't especially easy to follow, but is this a cascade of Serpent, Twofish, ChaCha20, and AES, all in CBC except for ChaCha, without an authenticator? With its own stream construction, that doesn't stop truncation?
- ezcrypt 2y agoThat's pretty much spot on. Authentication is planned (and that should handle truncation too if I'm not mistaking): https://codeberg.org/ezcrypt/ezcrypt/issues/3 https://codeberg.org/ezcrypt/ezcrypt/issues/3
- tptacek 2y agoPublic key signatures and ciphertext authentication are not the same thing.
- ezcrypt 2y agoNo, I realize that (I was thinking that ssh-keygen could be used as a poor-man's authentication for some use cases - basically share a secret between sender & receiver that can be used to ensure that the message has not been tampered with). One of the reasons that I haven't implemented authentication yet is that I want to better understand the differences and nuances of different methods and use cases before deciding on a method. Recommendations are welcome.
- tptacek 2y agoGet rid of the weird cipher cascade and replace it either with XAES-GCM or ChaPoly. Do some research into how to handle large ciphertexts with a chunking construction. Use a well-defined construction; don't invent your own.
- dist-epoch 2y agoPSA: it should be obvious that it's a really dumb idea to use random new encryption tools from GitHub (sorry, author)
- spease 2y ago> it should be obvious It should be, but a lot of developers don’t have formal security training, nor especially management which may end up selecting the contractors/developers and deciding on the technical approach. If it’s explicitly not production ready, it should probably say so up front, not advertise itself as “strong encryption”. However painful that may be.
- ezcrypt 2y agoAll good points. I intend to make it clearer: https://codeberg.org/ezcrypt/ezcrypt/issues/4 https://codeberg.org/ezcrypt/ezcrypt/issues/4
- sevg 2y agoDon't use this. It's missing a basic building block: authentication. Unfortunately, the author hasn't spent long enough researching cryptography. (Even the briefest of research would have made this mistake obvious.)
- ezcrypt 2y agoVery good point! I have been planning to look into authentication. I didn't need it for my use cases, yet, but as you say that should be an integral part of any serious tool. I added a ticket: https://codeberg.org/ezcrypt/ezcrypt/issues/3 https://codeberg.org/ezcrypt/ezcrypt/issues/3 In the meantime, signing and verification can be done separately, e.g. with ssh-keygen, although that is a bit inconvenient (which kind of defeats one of the key points of the tool).
- deleted 2y ago[deleted]
- everfree 2y agoWhat’s the advantage over symmetric PGP encryption?
- andrewmcwatters 2y ago> Encryption is done in four layers. What?
- tptacek 2y agoIt's a cipher cascade. (Don't build cipher cascades.)
- ezcrypt 2y agoThe idea isn't really to make the encryption stronger or to widen the key. It's a classical case of trust - if one cipher is compromised, there are others to cover for you. Also, I wanted to learn the different ciphers, and speed wasn't a top priority.
- tptacek 2y agoYeah, that's why everyone writes cipher cascades. There's a reason you don't see them in any mainstream vetted cryptography. The bigger problem is that none of this is authenticated.
- underlogic 2y agoWhy not exactly?
- CarpaDorada 2y agoDon't use cryptographic software from people refusing to identify themselves.
- ezcrypt 2y agoThis should be the top rated comment ;-) Sorry. I can't remedy the situation for you, though.
- gbraad 2y agoHave used axcrypt before; easy and portable
- ezcrypt 2y agoIf it's the AxCrypt I think it is, it doesn't even run on Linux, never mind Raspberry PI or Milk-V for instance. And it's not free either. So it doesn't meet many of my requirements, unfortunately.
- svantex 2y agoI'm the original author of AxCrypt. There's a new compatible iteration of it based on the original cryptography code called Xecrets, with several components. Xecrets Cli is the main fully featured command line engine, free open source GPL on https://github.com/xecrets/xecrets-cli https://github.com/xecrets/xecrets-cli . Xecrets Ez is a simple GUI frontend, single executable, portable. Runs on Linux, macOS and Windows. There are several more components available as nuget packages.
- ezcrypt 2y agoVery interesting! Thanks for the link, I didn't know about it and I'll have to check it out. It still falls slightly outside of my zone of preference, though, as it's a .Net application, which limits which platforms it can be run on (I'm aiming for a tool that can readily be used on most of my devices, including on an old Raspberry Pi or a router).
- svantex 2y agoFair enough, that's a little out of main scope for Xecrets Cli. Just for fun, I tested now to build and publish for an ARM processor running Linux (linux-arm) and the build worked fine. I don't have a device to test it on though. So... as long as it runs Linux and has an ARM or ARM64 processor and sufficient storage & memory it could work! (It's not tiny like a pure C-program unfortunately). Would be cool to try...!
- chasil 2y agoWhat's wrong with "openssl enc"?
- sirjaz 2y agoI'm just glad you support Windows. We need more of this!
- phinnino1 2y ago[dead]