[gnull]

That's such a user-hostile design decision. I can't fathom what justifies it (other than kinky taste).

Makes your commands unreadable without a manual, leaves a lot of room for errors that are quietly ignored. And forces you into using a shell that comes with its own set of gotchas, bash is not known to be a particularly good tool for security.

And to those who stay this adds flexibility: it doesn't. Those file descriptors are available under/dev/fd on linux, with named options you can do --pk /dev/fd/5. Or make a named pipe.

[minitech]

> Those file descriptors are available under/dev/fd on linux, with named options you can do --pk /dev/fd/5.

If you have a procfs mounted at /proc and the open syscall to use on it, sure (and even then, it’s wasteful and adds unnecessary failure paths). Even argument parsing is yet more code to audit.

I think the design is pretty good as-is.

[gnull]

It's 2025, dude. You can't be seriously telling me how difficult it is to parse arguments. It may be difficult in C, but then we're down another sick rabbit hole of justifying bad interface with bad language choice.

One open syscall in addition to dozens already made before your main function is started will have no observable effect whatsoever.

[minitech]

The context is what’s essentially a shell-accessible library for a minimal set of cryptographic primitives. It’s very reasonable to want it to be as lightweight, portable, and easy to audit as possible, and to want it to run in environments where (continuing on Linux for example) the open syscall to /dev/fd/n -> /proc/self/fd/n will not succeed for whatever reason, e.g. a restrictive sandbox.

Not involving argument parsing simplifies the interface regardless of how easy the implementation is, and the cost is just having to look up a digit in a manual that I certainly hope anyone doing raw ed25519 in shell is reading anyway.

[gnull]

Make a named pipe then. Shells have built-in primitives for that. I.e. <() and >() subshells in bash, or psub in fish. Or have an option to read either a file descriptor or a file.

I can't understand why you keep inflating the difficulty of simple commandline parsing, which the tool needs to do anyway — we shouldn't even be talking about it. Commandline parsing code is done once (and read once per audit) while a hostile user interface that bad commandline creates takes effort to use each time someone invokes the tool. If the tool has 1000 users, then bad interface's overhead has 1000× weight when we measure it against the overhead of implementing commandline parsing. This is preposterous.

> Not involving argument parsing simplifies the interface

From interface perspective, how is `5>secretkey` simpler than `--sk secretkey`? The latter is descriptive, searchable and allows bash completion. I'll type `ed25519-keypair`, hit tab and recall what the argument called.

You can't justify poorly made interface that is unusable without opening the manual side by side. Moreover, the simplest shell scripts that call this tool are unreadable (and thus unauditable) without the the manual.

  ed25519-keypair 5>secretkey 9>publickey

You see this line in a shell script. What does it do? Even before asking some deeper crypto-specific questions, you need to know what's written in "secretkey" and "publickey" files. You will end up spending your time (even a minute) and context-switch to check the descriptor numbers instead of doing something actually useful.

[minitech]

> which the tool needs to do anyway

It doesn’t. The tool has no command-line arguments.

Please learn how the various shell concepts you’re referencing (like <()) actually work and get back to me if you still need to after that.

In any case, I’m well aware of the readability benefit of named arguments, and was when I made the original comment. So as you can imagine, I maintain that it’s a more than reasonable tradeoff, and I’ve covered the reasons for that. If you have nothing (correct) to add beyond hammering on this point, save it.

[gnull]

You got me, it doesn't have arguments. Luckily, my argument did not critically rely on this bit, and it's still valid. Instead of occasional disconnected thoughts and vulgar attempts to insult, try to construct a complete, coherent argument for why you think your view is valid.

A suggestion on how you could approach it: try to make a table with 2-3 columns for the solutions you and I are comparing. And add a row for each aspect or characteristic you want to compare them with respect to; for example, usability, ease of implementation, room for error, you name it. In each cell, put either + or - if a solution is clearly managing that aspect well or badly, or a detailed comment. Try to express all of the things you're feeling and that are coming to your mind. My comments are written with a table like that in mind, they easily translate to one. Once you have made your table and established that we disagree on what some cell should contain or what rows/columns should be present, feel free to get back to have an actual discussion.

[minitech]

(nicer reply to this)

Yes, I’m aware of the readability benefit of named arguments, and made the original comment with that awareness too.

> Make a named pipe then. Shells have built-in primitives for that. I.e. <() and >() subshells in bash,

That’s /proc/self/fd again. But okay, you can make a named pipe to trade the procfs mount and corresponding open-for-read permission requirement for a named pipe open-for-write permission requirement without receiving the other benefits I listed of just passing a FD directly.

> I can't understand why you keep inflating the difficulty of simple commandline parsing

Not only have I not “kept inflating” this, I barely brought up the related concept of it being unnecessary complexity from an implementation side (which it is).

> which the tool needs to do anyway

It doesn’t. The tool has no command-line arguments.

> From interface perspective, how is `5>secretkey` simpler than `--sk secretkey`? The latter is descriptive, searchable and allows bash completion. I'll type `ed25519-keypair`, hit tab and recall what the argument called.

Not introducing More Than One Way To Do It after all (“Or have an option to read either a file descriptor or a file”) here is a good start, but it’s hard to beat passing a file descriptor for simplicity. If the program operates on a stream, the simplest interface passes the program a stream. (This program actually operates on something even simpler than a stream – a byte string – but Unix-likes, and shells especially, are terrible at passing those. And an FD isn’t just a stream, but the point is it’s closer.) A file path is another degree or more removed from that, and it’s up to the program if/how it’ll open that file path, or even how it’ll derive a file path from the string (does `-` mean stdin to this tool? does it write multiple files with different suffixes? what permissions does it set if the file is a new file – will it overwrite an existing file? is this parameter an input or an output?).

Your attached arguments seem to be about convenience during interactive use, rather than the kind of simplicity I was referring to. (Bonus minor point: tab completion is not necessarily any different.)

> Moreover, the simplest shell scripts that call this tool are unreadable (and thus unauditable) without the the manual.

That might be a stretch. But more importantly, who’s trying to audit use of these tools without the manual? You can be more sure of the program’s interpretation of `--sk secretkey` (well, maybe rather `--secret-key=./secretkey`) than `9>` if you know it runs successfully, but for anything beyond that, you do need to know how the program is intended to work.

Finally, something I probably should have mentioned earlier: it’s very easy to wrap the existing implementation in a shell function to give it a named-parameter filepath-based interface if you want, but the reverse is impossible.

[gnull]

I see, you are more focused on providing the core functionality in the simplest way possible from purely technical perspective, and less so on what kind of "language" or interface it provides the end user — assuming someone who wants an interface can make a wrapper. I can see that your points make sense from this perspective, the solution with FDs is indeed simpler from this viewpoint.

I, on the other hand, criticized it as a complete interface made with some workflow in mind that would need no wrappers, would help the user discover itself and avoid footguns. Your interpretation sounds like what the authors may have had in mind when they made it.

> who’s trying to audit use of these tools without the manual?

I'd try to work on different levels when understanding some system. Before getting into details, I'd try to understand the high-level components/steps and their dataflows, and then gradually keep refining the level of detail. If a tool has 2-3 descriptively named arguments and you have a high-level idea of what the tool is for, you can usually track the dataflows of its call quite well without manual. Say, understanding a command like

  make -B -C ./somewhere -k

may require the manual if you haven't worked with make in some time and don't remember the options. But

  make --always-make --directory=./somewhere --keep-going

gives you a pretty good idea. On the second read, where you're being pedantic with details, you may want to open the manual and check what those things exactly mean and guarantee, but it's not useless without the manual either.

[PunchyHamster]

it being option can be nice if you don't want your keys touching disk and need to pass it over to other apps.

it being default is insanity