migrate encryption mechanism from custom model class to an existing package

[theferrit32]

custom encrypted textfield class works fine

auth_microservice/src/microservice/token_service/models.py

Lines 5 to 24 in 4ba643e

	class EncryptedTextField(models.TextField):
	def __init__(self, *args, **kwargs):
	if crypt.instance == None:
	raise RuntimeError('crypt module not initialized')
	self.crypt = crypt.instance
	super().__init__(*args, **kwargs)
	# invoked to convert db value to python value
	def from_db_value(self, value, expression, connection):
	#print('EncryptedTextField.from_db_value value: ' + str(value))
	dec = self.crypt.decrypt(value)
	#print('EncryptedTextField.from_db_value({}) -> {}'.format(value, dec))
	return dec
	# invoked before saving python value to db value
	def get_prep_value(self, value):
	#print('EncryptedTextField.get_prep_value value: ' + str(value))
	enc = self.crypt.encrypt(value)
	#print('EncryptedTextField.get_prep_value({}) -> {}'.format(value, enc))
	return enc

However there are a couple of pip packages out there which can handle text along with dates and other object types, which could be nice.

https://github.com/dcwatson/django-pgcrypto

The one above additionally provides a custom lookup function for postgres which can decrypt and filter values natively in the db using postgres functions 'decrypt' and 'convert_from', instead of requiring a loop and filter on a queryset in python. django-encrypted-fields package does not. This almost certainly improves performance even though it is still having to decrypt and decode every row of the table.