Crashing during JsonLD signing on Android

[kenneth-leong-gt]

Is this library able to be used in an Android device? I am getting exception for the instantiation of com.danubetech.keyformats.crypto.provider.impl.NaClSodiumEd25519Provider when running in Android.

Full stack trace below

java.util.ServiceConfigurationError: com.danubetech.keyformats.crypto.provider.Ed25519Provider: Provider com.danubetech.keyformats.crypto.provider.impl.NaClSodiumEd25519Provider could not be instantiated
	at java.util.ServiceLoader.fail(ServiceLoader.java:233)
	at java.util.ServiceLoader.-$$Nest$smfail(Unknown Source:0)
	at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:392)
	at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:416)
	at java.util.ServiceLoader$1.next(ServiceLoader.java:494)
	at com.danubetech.keyformats.crypto.provider.Ed25519Provider.get(Ed25519Provider.java:27)
	at com.danubetech.keyformats.crypto.impl.Ed25519_EdDSA_PrivateKeySigner.sign(Ed25519_EdDSA_PrivateKeySigner.java:19)
	at com.danubetech.keyformats.crypto.ByteSigner.sign(ByteSigner.java:18)
	at info.weboftrust.ldsignatures.signer.Ed25519Signature2020LdSigner.sign(Ed25519Signature2020LdSigner.java:37)
	at info.weboftrust.ldsignatures.signer.Ed25519Signature2020LdSigner.sign(Ed25519Signature2020LdSigner.java:48)
	at info.weboftrust.ldsignatures.signer.LdSigner.sign(LdSigner.java:99)
	at info.weboftrust.ldsignatures.signer.LdSigner.sign(LdSigner.java:123)
	at com.example.FirstFragmentViewModel.webOfTrustSigner(FirstFragmentViewModel.kt:484)
	at com.example.FirstFragmentViewModel.access$webOfTrustSigner(FirstFragmentViewModel.kt:45)
	at com.example.FirstFragmentViewModel$createSignVP$1.invokeSuspend(FirstFragmentViewModel.kt:399)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
	at kotlinx.coroutines.internal.LimitedDispatcher.run(LimitedDispatcher.kt:42)
	at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:95)
	at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:570)
	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750)
	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:677)
	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:664)
	Suppressed: kotlinx.coroutines.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@d91dd9a, Dispatchers.IO]
Caused by: java.lang.ExceptionInInitializerError
	at java.lang.Class.newInstance(Native Method)
	at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:388)
	... 20 more
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.net.URL.getFile()' on a null object reference
	at com.goterl.resourceloader.ResourceLoader.getFileFromFileSystem(ResourceLoader.java:234)
	at com.goterl.resourceloader.ResourceLoader.copyToTempDirectory(ResourceLoader.java:88)
	at com.goterl.resourceloader.SharedLibraryLoader.load(SharedLibraryLoader.java:53)
	at com.goterl.lazysodium.utils.LibraryLoader.loadBundledLibrary(LibraryLoader.java:134)
	at com.goterl.lazysodium.utils.LibraryLoader.loadLibrary(LibraryLoader.java:95)
	at com.goterl.lazysodium.SodiumJava.<init>(SodiumJava.java:34)
	at com.goterl.lazysodium.SodiumJava.<init>(SodiumJava.java:23)
	at com.danubetech.keyformats.crypto.provider.impl.NaClSodiumEd25519Provider.<clinit>(NaClSodiumEd25519Provider.java:15)
	... 22 more

[peacekeeper]

Hello @kenneth-leong-gt thanks for your feedback. Could you please check issue danubetech/key-formats-java#11 on the "key-formats-java" library to see if that solves the problem? If not, or if that other issue discussion isn't clear, please reply back here and we'll take another look to help!

[kenneth-leong-gt]

ok seems to be working using the tink povider now. Thank you very much.

But one comment on the api for Ed25519Signature2020LdSigner constructor.

public Ed25519Signature2020LdSigner(byte[] privateKey) {

       this(new Ed25519_EdDSA_PrivateKeySigner(privateKey));
   }

It states that the param needed is the byte array for the private key, but actually it requires the private key byte array concat-ed with the public key byte array as internally its checking for 64 bytes for the byte array length. As shown in this check below.

@Override
	public byte[] sign(byte[] content, byte[] privateKey) throws GeneralSecurityException {

		if (privateKey.length != Ed25519Sign.SECRET_KEY_LEN + Ed25519Verify.PUBLIC_KEY_LEN) throw new GeneralSecurityException("Invalid private key length: " + privateKey.length); // <-------this check here

		byte[] privateKeyOnly = new byte[32];
		System.arraycopy(privateKey, 0, privateKeyOnly, 0, Ed25519Sign.SECRET_KEY_LEN);

		byte[] signatureValue = new Ed25519Sign(privateKeyOnly).sign(content);

		return signatureValue;
	}

So kinda confusing imo.

[peacekeeper]

It states that the param needed is the byte array for the private key, but actually it requires the private key byte array concat-ed with the public key byte array

I agree this is confusing, however we did this to mirror what libsodium has been doing, where in several places the public and private keys are used together. Not sure what's the reason for this.

See e.g. here:

• https://github.com/jedisct1/libsodium/blob/master/src/libsodium/include/sodium/crypto_sign_ed25519.h#L34
• https://github.com/terl/lazysodium-java/blob/master/src/main/java/com/goterl/lazysodium/interfaces/Sign.java#L27

I suppose the Tink approach is better, where the "private key" is really only the private key.

[peacekeeper]

I just added two commits which hopefully document the issues that were raised here a bit:

danubetech/key-formats-java@433dd83
danubetech/key-formats-java@0680972

[kenneth-leong-gt]

thanks for the updates. btw are there any plans for something like ld-signatures-swift or anything for iOS?

[peacekeeper]

No sorry, at the moment we don't have plans to implement this in any other lanaguge...

[peacekeeper]

Can we close this issue?

[kenneth-leong-gt]

yes, thanks