Fix compressed TOASTs encryption/decryption #76
Merged
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
If TOAST data gets compressed, it has an extended header containing compression info. We used to encrypt this header along with the actual data which in turn caused a crash as PG needs this data in later stages. So it should be taken into account while encrypting data during externalisation.
Then, during detoasting, we should not decrypt this compression header as it is being extracted with the data with the first TOAST chunk. So, copy the first N bytes (now it is 4 bytes) of the first chunk as it is and decrypt the rest of the data.
Fixes #63