bioConversionFailure in ECDSAKey when using P384

[NeedleInAJayStack]

Describe the bug

When a P384 private key from Crypto is used to create a ECDSAKey, I get the following error in release mode on MacOS:

JWTKit error: signing algorithm error: bioConversionFailure

However, when using a P256 private key, creating a ECDSAKey does not error.

To Reproduce

Build and run the following in release mode:

import JWT
import Crypto

let generatedPriv = P384.Signing.PrivateKey()
let priv = try ECDSAKey.private(pem: generatedPriv.pemRepresentation)
let pub = try ECDSAKey.public(pem: generatedPriv.publicKey.pemRepresentation)

Note that just switching P256 out for P384 is able to run without error.

Expected behavior

I would expect that a P384 curve would be able to be used without error.

Environment

• Vapor Framework version: 4.78.0
• Vapor Toolbox version: 18.7.1
• OS version: MacOS 13.4.1
• swift-crypto: 2.6.0
• jwt: 4.2.2

Additional context

None

[vzsg]

I ran the code out of curiousity inside Xcode and Linux, in both debug and release configurations, and I'm not experiencing any issues. Is it consistently happening for you?

[0xTim]

Yeah I've just run this in a new project on macOS in release mode in VSCode and it worked fine for me too

[fibrechannelscsi]

This is occurring on the nightly toolchains. I've installed the latest 09-05 toolchain (in the default location for macOS) and attempted to run it as such:
/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2023-09-05-a.xctoolchain/usr/bin/swift run -c release
and I get the following:

[918/918] Linking bssl
Build complete! (156.02s)
Swift/ErrorType.swift:200: Fatal error: Error raised at top level: JWTKit error: signing algorithm error: bioConversionFailure
zsh: trace trap   run -c release

Toolchains 2023-08-27a and 2023-08-03a also exhibit this issue.

[0xTim]

Have you tried the code without JWT and just using Swift Crypto?

import Crypto

let generatedPriv = P384.Signing.PrivateKey()
let priv = try ECDSAKey.private(pem: generatedPriv.pemRepresentation)
let pub = try ECDSAKey.public(pem: generatedPriv.publicKey.pemRepresentation)

None of that code is JWT stuff IIRC. If that also fails it's probably better to open an issue there

[GNMoseke]

ECDSAKey is a JWTKit Type.

The error itself is also in JWTKit here. My suspicion personally is that something in one of the new nightly toolchains is optimizing out something in boringSSL when compiling in release mode.

Potentially related is that JWTKit and Swift Crypto bundle 2 different versions of boringSSL on linux, but I don't know why that would cause this issue to crop up on macOS. I know there's already a PR in progress to remove the bundled boringSSL which may help.

[BradLarson]

I tested this against top-of-tree Swift as of the 2023-09-20 nightly trunk snapshot, and I still experience the bioConversionFailure described above with that toolchain. I do not see it with the 5.9 release branch toolchains, so this appears to be due to something in main since the 5.9 branch point. That means it won't be reproducible in Xcode 15's default Swift toolchain, but it is still an issue with Swift main after the 5.9 branch point.

[0xTim]

We'll keep an eye on this - we're almost finished ripping out BoringSSL (#99) at which point this should no longer be an issue

[0xTim]

Going to transfer this to JWTKit as that's where the code lives and we can just write a test to ensure it's no longer an issue

cc @ptoffy

[BradLarson]

Just to confirm, the jwtkit-5 branch (and matching v5 branch of JWT) no longer experiences this issue in the above reproducer with nightly Swift toolchain snapshots, as anticipated after the move off of BoringSSL. Once that's in main, this should be fully resolved.

[0xTim]

Oh that's great to hear!