Fix 'missing provider' exception for KeyStoreTypes which do not have specific provider

[ls-bit]

Some of the KeyStoreTypes like PKCS12 do not seem to return a provider which lead to the exception below. This small patch seems to fix it.

Exception in thread "main" java.lang.IllegalArgumentException: missing provider
	at java.base/sun.security.jca.GetInstance.getService(GetInstance.java:96)
	at java.base/sun.security.jca.GetInstance.getInstance(GetInstance.java:218)
	at java.base/java.security.Signature.getInstance(Signature.java:449)
	at net.jsign.jca.JsignJcaProvider$JsignJcaSignature.engineInitSign(JsignJcaProvider.java:204)
	at java.base/java.security.Signature$Delegate.tryOperation(Signature.java:1322)
	at java.base/java.security.Signature$Delegate.chooseProvider(Signature.java:1276)
	at java.base/java.security.Signature$Delegate.engineInitSign(Signature.java:1360)
	at java.base/java.security.Signature.initSign(Signature.java:636)

[ebourg]

Thank you for the PR. How did you trigger this error?

[ls-bit]

For context, I was testing to integrate Jsign and marketplace-zip-signer. For that, I made changes to marketplace-zip-signer in my fork to allow passing the provider class and arg here https://github.com/ls-bit/marketplace-zip-signer/pull/1/files

Then I ran following command:

java -cp marketplace-zip-signer-cli.jar:jsign.jar org.jetbrains.zip.signer.ZipSigningTool sign \
 -in test.zip  \
 -out signed.zip \
 -ks NONE \
 -ks-pass changeit \
 -ks-provider-class net.jsign.jca.JsignJcaProvider \ 
 -ks-provider-arg example.p12 \
 -cert example.crt \ 
 -ks-key-alias test \
 -ks-type pkcs12 \
 -ks-provider-name Jsign

Full stacktrace

Exception in thread "main" java.lang.IllegalArgumentException: missing provider at java.base/sun.security.jca.GetInstance.getService(GetInstance.java:96) at java.base/sun.security.jca.GetInstance.getInstance(GetInstance.java:218) at java.base/java.security.Signature.getInstance(Signature.java:449) at net.jsign.jca.JsignJcaProvider$JsignJcaSignature.engineInitSign(JsignJcaProvider.java:204) at java.base/java.security.Signature$Delegate.tryOperation(Signature.java:1322) at java.base/java.security.Signature$Delegate.chooseProvider(Signature.java:1276) at java.base/java.security.Signature$Delegate.engineInitSign(Signature.java:1360) at java.base/java.security.Signature.initSign(Signature.java:636) at org.jetbrains.zip.signer.signing.DefaultSignatureProvider.sign(DefaultSignatureProvider.kt:16) at org.jetbrains.zip.signer.signing.SigningKt.generateSignatureOverData(Signing.kt:41) at org.jetbrains.zip.signer.signing.SigningKt.generateSignerBlock(Signing.kt:27) at org.jetbrains.zip.signer.signing.ZipSigner.sign(ZipSigner.kt:81) at org.jetbrains.zip.signer.signing.ZipSigner.sign(ZipSigner.kt:31) at org.jetbrains.zip.signer.ZipSigningTool.sign(ZipSigningTool.kt:81) at org.jetbrains.zip.signer.ZipSigningTool.main(ZipSigningTool.kt:32)

I will say that there is a non-zero chance that I am doing something wrong or that I got the implementation wrong