GH-3282: Add encryption info CLI support for Parquet file encryption metadata

[ArnavBalyan]

• Since Parquet 1.12, encryption has become a first class citizen, with support for footer and column level encryption.
• However, users have no clear way to check encryption metadata, mode, or whether footer/file is encrypted.
• This PR adds a simple, dedicated CLI command: parquet-cli encryption-info <file>
• The command reports the following:
  • File-level encryption type: PLAINTEXT_FOOTER or ENCRYPTED_FOOTER.
  • Summary of column encryption, per-column details and their encryption status.

[ArnavBalyan]

cc @shangxinli @gszadovszky could you please take a look thanks!

[nandorKollar]

I think it would be nice to also print out details about the encryption algorithm, wouldn't it?

[ArnavBalyan]

yeah that's a great point will add support

[wgtmac]

cc @ggershinsky @shangxinli for experts on encryption

[ggershinsky]

Some other details worth printing -

• is a column encrypted with the footer key or with a column-specific key?
• if all columns are encrypted with the footer key, then the file is in "uniform encryption" mode; can print this (so the user knows one key only is used in a file and can open every column)
• explicit info on the footer encryption mode - encrypted or plaintext
• optional (via a flag) printing of the key metadata of the footer key and (if available) of the column keys - can be useful for debugging key retrieval. This is binary, but maybe something similar to "hexdump -C" can be performed where some effort is made to find/print ASCII text chunks (often, key metadata has text/json parts)
• advanced debugging: print the AAD-related fields

[ArnavBalyan]

Some other details worth printing -

• is a column encrypted with the footer key or with a column-specific key?
• if all columns are encrypted with the footer key, then the file is in "uniform encryption" mode; can print this (so the user knows one key only is used in a file and can open every column)
• explicit info on the footer encryption mode - encrypted or plaintext
• optional (via a flag) printing of the key metadata of the footer key and (if available) of the column keys - can be useful for debugging key retrieval. This is binary, but maybe something similar to "hexdump -C" can be performed where some effort is made to find/print ASCII text chunks (often, key metadata has text/json parts)
• advanced debugging: print the AAD-related fields

Thanks this is great feedback I'll iterate and update this shortly

[github-actions]

This pull request has been automatically marked as stale because it has had no activity for at least 2 months. If you are still working on this change or plan to move it forward, please leave a comment or push a new commit so we know to keep it open. Otherwise, this PR will be closed automatically in about one month. Thank you for your contribution to Apache Parquet!

[github-actions]

Closing this pull request due to at least 3 months of inactivity. If you would like to continue the work, please feel free to reopen this pull request or open a new one. Thank you for your contribution to Apache Parquet!