Bug 24151: Copy info to the pseudonymized table when a transaction is done

Bug 24151: Copy info to the pseudonymized table when a transaction is done

This is the commit where you will find useful information about this development.

The goal of this new feature is to add a way to pseudonymize patron's
data, in a way they could not be personally identifiable.
https://en.wikipedia.org/wiki/Pseudonymization

There are different existing way to anonymize patron's information in
Koha, but we loose the ability to make useful report.
This development proposes to have 2 different tables:
  * 1 for transactions and patrons data (pseudonymized_transactions)
  * 1 for patrons' attributes (pseudonymized_borrower_attributes)
Entries to pseudonymized_transactions are added when a new transaction
(checkout, checkin, renew, on-site checkout) is done.
Also, anonymized_borrower_attributes is populated if patron's attributes are
marked as "keep for pseudonymization".

To make those informations not identifiable to a patron, we are having a
hashed_borrowernumber column in pseudonymized_transactions. This hash will be
generated (Blowfish-based crypt) using a key stored in the Koha
configuration.

To make things configurable, we are adding 3 sysprefs and 1 new DB
column:
  * syspref Pseudonymization to turn on/off the whole feature
  * syspref PseudonymizationPatronFields to list the informations of the
  patrons to sync
  * syspref PseudonymizationTransactionFields to list the informations
  of the transactions to copy
  * DB column borrower_attribute_types.keep_for_pseudonymization that is a
  boolean to enable/disable the copy of a given patron's attribute type.

Test plan:
1/ Turn on Pseudonymization
2/ Define in PseudonymizationPatronFields and
PseudonymizationTransactionFields the different fields you want to copy
3/ Go to the about page
=> You will see a warning about a missing config entry
4/ You need to generate a key and put it in the koha-conf.xml file. The
following command will generate one:
  % htpasswd -bnBC 10 "" password | tr -d ':\n' | sed 's/$2y/$2a/'
Then edit $KOHA_CONF and add it before of the end of the config section (</config)
  it should be something like:
    <key>$2a$10$PfdrEBdRcL2MZlEtKueyLegxI6zg735jD07GRnc1bt.N/ZYMvBAB2</key>
5/ Restart memcached then plack (alias restart_all)
=> Everything is setup!
6/ Create a new transaction (checkin for instance)
=> Confirm that a new entry has been added to pseudonymized_transaction with the data
you expect to be copied
7/ Edit some patron attribute types and tick "Keep for pseudonymization"
8/ Create a new transaction
=> Confirm that new entries have been added to pseudonymized_borrower_attributes
11/ Delete the patrons
=> Confirm that the entries still exist in the pseudonymized_* tables
12/ Purge the patrons (ie. use cleanup_database.pl to remove them from
the deleted_borrowers table)
=> Confirm that the entries still exist in the pseudonymized_* tables

See bug 24152 to remove data from the anonymized_* tables

Sponsored-by: Association KohaLa - https://koha-fr.org/

Signed-off-by: Signed-off-by: Sonia Bouis <sonia.bouis@univ-lyon3.fr>

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>