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