Error message from signapk.jar

[ChunghaSung]

Hi,

when I tried to sign the apk after instrumentation, it shows this error when I ran this command:
java -jar signapk.jar testkey.x509.pem testkey.pk8 sootOutput/ex1-1.apk ex1-1_signed.apk

Exception in thread "main" java.lang.NoClassDefFoundError: sun/misc/BASE64Encoder
at com.android.signapk.SignApk.addDigestsToManifest(SignApk.java:169)
at com.android.signapk.SignApk.main(SignApk.java:325)
Caused by: java.lang.ClassNotFoundException: sun.misc.BASE64Encoder
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
... 2 more

I couldn't find any source code for this jar so it is hard to figure out the problem.
Can I just sign the app in my own way? such as using jarsigner provided by bash command?
I am not sure if this affects the result.

[archer29m]

First of all, yes you can sign the app using any approach. Just make sure that sometimes you need to delete the META-INF file inside the instrumented apk file before signing the app.
The above command should also work. There is no specific dependency for the signapk.jar file to cause missing things. The error that you are getting is because of your java version I guess (might be 9 or 10) that is why I think it cannot find BASE64Encoder class. Please use Java 8 for all experiments (that's the java version that we used because at that time soot was only working with java 8).

[NavinShankar]

Hi,
Back to the same topic again, I'm facing the same issue with Java version 15.0.1.
is there any other option to resolve this concern

[virogu]

Is there any other option to resolve this concern，my project and gradle all require jdk11+, but the "sinapk.jar" require jdk1.8, how should I do? Is there a newer version of "sinapk.jar" compatible with this error