Initial changes to support the new Django 1.6 project structure

mayan/apps/document_signatures/managers.py

@@ -0,0 +1,80 @@
+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()