When trying use stax APIs to encrypt and decrypt attachments using AES_GCM_128, it breaks with error saying
Caused by: java.lang.IllegalStateException: Cipher not initialized
at javax.crypto.Cipher.d(Unknown Source)
at javax.crypto.Cipher.doFinal(Unknown Source)
at javax.crypto.CipherInputStream.close(Unknown Source)
Please note that same code works for AES_128 with attachments.
Also, I looked into the code stax code, found that org.apache.xml.security.stax.impl.processor.input.AbstractDecryptInputProcessor.processEvent(InputProcessorChain, boolean) has
final int ivLength = JCEAlgorithmMapper.getIVLengthFromURI(algorithmURI) / 8;
Not sure if ivLength used for GCM could be the problem?