Provide option to validate transmission fixity

[mjordan]

Just an idea, but related to Islandora/documentation#867:

Workbench could verify transmission fixity by generating a digest for a file prior to PUTing it, then, once the file has been ingested, getting its checksum via the technique implemented in mjordan/islandora_riprap#33 implemented in the Islandora Workbench Integration module.

[mjordan]

Notes about what values Workbench will need to fetch and compare are in the linked Integration module issue.

[mjordan]

Would be useful to not only generate the hash in realtime, but also be optionally able to compare that hash to a known one in a reserved CSV column. One use of this is during migrations, where you want to confirm that the hash of the file on the source system (stored in the CSV) matches the newly generated hash, which in turn should match the hash Workbench verifies with Drupal.

[mjordan]

Complete for files identified in the "files" column (e.g. not for "additional files"). Docs are at https://mjordan.github.io/islandora_workbench_docs/fixity/.

Note: to use this feature, you must be running a version of the Islandora Workbench Integration module containing commit aac4a2402dd43c6ced5288a6d78c3fd5c24298cc (Aug. 3, 2021) or newer.