81 lines
2.8 KiB
Python
81 lines
2.8 KiB
Python
import logging
|
|
|
|
from django.db import models
|
|
|
|
from django_gpg.runtime import gpg
|
|
from django_gpg.exceptions import GPGVerificationError
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
class DocumentVersionSignatureManager(models.Manager):
|
|
def get_document_signature(self, document):
|
|
document_signature, created = self.model.objects.get_or_create(
|
|
document_version=document.latest_version,
|
|
)
|
|
|
|
return document_signature
|
|
|
|
def add_detached_signature(self, document, detached_signature):
|
|
document_signature = self.get_document_signature(document)
|
|
|
|
if document_signature.has_embedded_signature:
|
|
raise Exception('document already has an embedded signature')
|
|
else:
|
|
if document_signature.signature_file:
|
|
logger.debug('Existing detached signature')
|
|
document_signature.delete_detached_signature_file()
|
|
document_signature.signature_file = None
|
|
document_signature.save()
|
|
|
|
document_signature.signature_file = detached_signature
|
|
document_signature.save()
|
|
|
|
def has_detached_signature(self, document):
|
|
document_signature = self.get_document_signature(document)
|
|
|
|
if document_signature.signature_file:
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def has_embedded_signature(self, document):
|
|
logger.debug('document: %s' % document)
|
|
|
|
document_signature = self.get_document_signature(document)
|
|
|
|
return document_signature.has_embedded_signature
|
|
|
|
def detached_signature(self, document):
|
|
document_signature = self.get_document_signature(document)
|
|
|
|
return document_signature.signature_file.storage.open(document_signature.signature_file.path)
|
|
|
|
def verify_signature(self, document):
|
|
document_descriptor = document.open(raw=True)
|
|
detached_signature = None
|
|
if self.has_detached_signature(document):
|
|
logger.debug('has detached signature')
|
|
detached_signature = self.detached_signature(document)
|
|
args = (document_descriptor, detached_signature)
|
|
else:
|
|
args = (document_descriptor,)
|
|
|
|
try:
|
|
return gpg.verify_file(*args, fetch_key=True)
|
|
except GPGVerificationError:
|
|
return None
|
|
finally:
|
|
document_descriptor.close()
|
|
if detached_signature:
|
|
detached_signature.close()
|
|
|
|
def clear_detached_signature(self, document):
|
|
document_signature = self.get_document_signature(document)
|
|
if not document_signature.signature_file:
|
|
raise Exception('document doesn\'t have a detached signature')
|
|
|
|
document_signature.delete_detached_signature_file()
|
|
document_signature.signature_file = None
|
|
document_signature.save()
|