adamreeve commented on PR #54884: URL: https://github.com/apache/arrow/pull/54884#issuecomment-6353558293
I was also a bit confused about how signing and verifying the footer with AES-CTR would even work, because AES-CTR doesn't write a tag. It looks like we just assume the last 16 bytes of the encrypted data are the GCM tag when writing: https://github.com/apache/arrow/blob/14132604b3949ba1c25cc79fff2e1782b9efc413/cpp/src/parquet/metadata.cc#L885-L886 And then do the same when reading: https://github.com/apache/arrow/blob/14132604b3949ba1c25cc79fff2e1782b9efc413/cpp/src/parquet/metadata.cc#L1217-L1218 So the "tag" is actually just the last bytes of the AES-CTR encrypted data and the round trip succeeds -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
