(I would have called it
stop-piping-the-internet-into-your-shell, but that
seemed too long.)
$ curl -sSL https://get.rvm.io | bash
$ pipethis https://get.rvm.io
or (assuming not everybody has adopted my awesome idea but you still want to improve your life)
$ pipethis --no-verify --inspect https://get.rvm.io
$ curl -sSL https://get.rvm.io | pipethis --no-verify | bash
$ go get github.com/ellotheth/pipethis
or download the binary and
drop it in your
People piping the installers
pipethis [ OPTIONS ] <script> OPTIONS --target <exe> The shell or other binary that will run the script. Defaults to the SHELL environment variable. --lookup-with <keybase,local> The service you'll use to verify the author's identity: keybase (default) Use https://keybase.io local Use your local GnuPG public keyring If you're piping a script from `stdin`, the service will be forced to `local`. --inspect If set, open the script in an editor before checking the author. Ignored if you're piping a script from `stdin`. --editor <editor> The editor binary to use when --inspect is set. Defaults to the EDITOR environment variable. --no-verify If set, skips author and signature verification entirely. You'll need to set this if <script> doesn't support pipethis yet. --signature <signature file> The detached signature to verify <script> against. You'll only need this in a couple scenarios: - You've already downloaded the detached signature and you want to use your downloaded copy, or - the signature is hosted in a non-standard location (i.e. it's not <script>.sig), or - you're piping a script with a detached signature from `stdin`.
If you’re piping scripts into
pipethis directly from
curl, you’ll need
to have the script authors’ PGP keys already stored in your local keyring.
Don’t worry, they’ll have instructions!
People writing the installers
You can add one line to your installer script to make it support
but there’s other stuff to do as well:
- Get an account on Keybase. I know, Real Crypto Geeks™ hate Keybase because Browser Crypto Is Unsafe™ and They Can Store Your Private Key®. It’s a place to start, yo, just do it.
Alternatively, you can hand out your public key at key signing parties (because you’re a Real Crypto Geek™, remember?), and tell people to import it into their local public keyrings. 2. Add one line to your installation script to identify yourself. You can throw it in a comment:
``` # // ; '' PIPETHIS_AUTHOR your_name_or_your_key_fingerprint ```
Create a signature for the script. With Keybase, that’s:
$ keybase pgp sign -i yourscript.sh -d -o yourscript.sh.sig
but you’re a Real Crypto Geek™, so you’ll use
``` $ gpg --detach-sign -a -o yourscript.sh.sig yourscript.sh ```
Both those commands create ASCII-armored signatures. Binary signatures work too.
Alternatively, you can clearsign the script with an attached signature::
``` $ keybase pgp sign -i yourscript.unsigned.sh -c -o yourscript.sh ``` ``` $ gpg --clearsign -a -o yourscript.sh yourscript.unsigned.sh ```
- Pop the script (and the signature, if it’s detached) up on your web server.
- Replace your copy-paste-able installation instructions!
What’s all this noise
Who’s piped the
installation script for their
favorite tool directly from
curl into their shell?
Show of hands? Come on, you know
Don’t feel bad, so have I! So have we all, really. It’s so easy, so fast, so
clean, so…well, bad
- Network errors happen. Why pay for them in the middle of an install?
- Is your source served over SSL? No? Grats, you have no idea what you’re downloading or where it came from. Exciting!
- What’s that? Your source is served over SSL? Great! Any disgruntled employees have access to that server? Any trolls? Hey cool, you still have no idea what you’re downloading!
There are simple solutions to some of those problems:
- Cache the script before you shove it into Bash.
- Use something like vipe to pipe the script into an editor so you can review it before you run it.
- Use hashpipe to check the file hash before you run it.
But simple solutions are, like, boring, and stuff.
Why I’m here
The more interesting problem (to me, anyway) is authenticity. You trust whoever wrote the script; how can you be reasonably sure the script you download is the one they wrote?
What if every installation script was embedded with the cryptographic signature of its author, and you could verify the author and the script against the signature when you ran it?
How it works
Scripts that support
pipethis will embed a special line that identifies the
#!/usr/bin/bash # PIPETHIS_AUTHOR gemma echo woooooo look how verified everything is!
If you drop
--inspect on the command line,
pipethis with throw the script
into your favorite editor before it does anything else, and you can check the
author (and the rest of the content) yourself.
If you’re happy with the script contents,
Keybase for any users that match
uses the same search you find in the search box on their website, so you could
use a username, a Twitter handle, or even a key fingerprint.) It’ll spit all
the matches back at you in a list, along with all their Keybase proofs. Once
you choose one,
pipethis grabs the public key for that user. If you don’t see
the person you’re looking for, you can bail. No harm, no foul.
I found 2 results: 0: Identifier: gemma Twitter: ellotheth Github: ellotheth Hacker News: gemma Reddit: Fingerprint: 417b9f99b7c04ccebd06777d0bc6bb965aa6f296 Site: ramblinations.com Site: ramblinations.com 1: Identifier: gemmakbarlow Twitter: gemmakbarlow Github: gemmakbarlow Hacker News: gemmakbarlow Reddit: Fingerprint: 1fd52e9237fef588e2d0d26100fee8d483374357
Once you’ve picked an author,
pipethis will go grab their detached PGP
signature for the script. If
--signature is not given on the command line,
pipethis will tack
.sig onto the end of the script location and try that
With the signature and public key in hand,
pipethis will verify that the
signature matches both the key and the script. If it does, you’re good to go,
pipethis will run the script for you (against the executable of your
choice). If not,
pipethis dies, cleans itself up, and nobody ever has to know
that you almost pwned yourself.
It’s not done yet
pipethis works, but it can be better!
- There are zillions of other places to get public keys for people, and I want to support more of them. I think Keybase is stellar and I love what they’re trying to do, but nobody likes to be locked in to one provider.