Overview

graal-json-decoding-issue is a repo to help demonstrate JWT decoding issue with Graal's native image / SubstrateVM and 0auth JWT library.

Setup Steps

• Run ./gradlew run to run the application and observe correct output

To observe error on native image:

1. Run ./scripts/graal/bin/setup.sh to setup Graal VM SDK
2. Run ./scripts/graal/bin/dist.sh to create uber-jar package and compile to native image under dist/
3. Run java -jar ./dist/graal-json-decoding-issue.jar to observe correct result
4. Run ./dist/graal-json-decoding-issue to observe error (as below)

Actual vs Expected Output

Expected output:

Username: famous

Actual output (native image):

The string '{"typ":"JWT","alg":"HS256"}' doesn't have a valid JSON format.
com.auth0.jwt.impl.JWTParser.decodeException(JWTParser.java:75)
com.auth0.jwt.impl.JWTParser.parseHeader(JWTParser.java:51)
com.auth0.jwt.JWTDecoder.<init>(JWTDecoder.java:40)
com.auth0.jwt.JWTVerifier.verify(JWTVerifier.java:369)
com.hhandoko.graaldecoding.Application.main(Application.java:19)