added checksums for archived documents.

src/documents/consumer.py

@@ -6,6 +6,7 @@ import os
 import magic
 from django.conf import settings
 from django.db import transaction
+from django.db.models import Q
 from django.utils import timezone
 
 from .classifier import DocumentClassifier, IncompatibleClassifierVersionError
@@ -42,7 +43,7 @@ class Consumer(LoggingMixin):
     def pre_check_duplicate(self):
         with open(self.path, "rb") as f:
             checksum = hashlib.md5(f.read()).hexdigest()
-        if Document.objects.filter(checksum=checksum).exists():
+        if Document.objects.filter(Q(checksum=checksum) | Q(archive_checksum=checksum)).exists():  # NOQA: E501
             if settings.CONSUMER_DELETE_DUPLICATES:
                 os.unlink(self.path)
             raise ConsumerError(
@@ -184,6 +185,11 @@ class Consumer(LoggingMixin):
                     self._write(document.storage_type,
                                 archive_path, document.archive_path)
 
+                    with open(archive_path, 'rb') as f:
+                        document.archive_checksum = hashlib.md5(
+                            f.read()).hexdigest()
+                        document.save()
+
                 # Delete the file only if it was successfully consumed
                 self.log("debug", "Deleting file {}".format(self.path))
                 os.unlink(self.path)

src/documents/management/commands/document_archiver.py

@@ -1,3 +1,4 @@
+import hashlib
 import multiprocessing
 
 import ocrmypdf
@@ -27,6 +28,8 @@ def handle_document(document):
     parser.parse(document.source_path, mime_type)
     if parser.get_archive_path():
         shutil.copy(parser.get_archive_path(), document.archive_path)
+        with document.archive_file as f:
+            document.archive_checksum = hashlib.md5(f.read()).hexdigest()
     else:
         logging.getLogger(__name__).warning(
             f"Parser {parser} did not produce an archived document "

src/documents/migrations/1005_checksums.py

@@ -0,0 +1,23 @@
+# Generated by Django 3.1.3 on 2020-11-29 00:48
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('documents', '1004_sanity_check_schedule'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='document',
+            name='archive_checksum',
+            field=models.CharField(blank=True, editable=False, help_text='The checksum of the archived document.', max_length=32, null=True),
+        ),
+        migrations.AlterField(
+            model_name='document',
+            name='checksum',
+            field=models.CharField(editable=False, help_text='The checksum of the original document.', max_length=32, unique=True),
+        ),
+    ]

src/documents/models.py

@@ -157,9 +157,15 @@ class Document(models.Model):
         max_length=32,
         editable=False,
         unique=True,
-        help_text="The checksum of the original document (before it was "
-                  "encrypted).  We use this to prevent duplicate document "
-                  "imports."
+        help_text="The checksum of the original document."
+    )
+
+    archive_checksum = models.CharField(
+        max_length=32,
+        editable=False,
+        blank=True,
+        null=True,
+        help_text="The checksum of the archived document."
     )
 
     created = models.DateTimeField(

src/documents/sanity_checker.py

@@ -67,30 +67,34 @@ def check_sanity():
                 f"Original of document {doc.pk} does not exist."))
         else:
             present_files.remove(os.path.normpath(doc.source_path))
-            checksum = None
             try:
                 with doc.source_file as f:
                     checksum = hashlib.md5(f.read()).hexdigest()
             except OSError as e:
                 messages.append(SanityError(
                     f"Cannot read original file of document {doc.pk}: {e}"))
-
-            if checksum and not checksum == doc.checksum:
+            else:
+                if not checksum == doc.checksum:
                     messages.append(SanityError(
                         f"Checksum mismatch of document {doc.pk}. "
                         f"Stored: {doc.checksum}, actual: {checksum}."
                     ))
 
         if os.path.isfile(doc.archive_path):
+            present_files.remove(os.path.normpath(doc.archive_path))
             try:
                 with doc.archive_file as f:
-                    f.read()
+                    checksum = hashlib.md5(f.read()).hexdigest()
             except OSError as e:
                 messages.append(SanityError(
                     f"Cannot read archive file of document {doc.pk}: {e}"
                 ))
-
-            present_files.remove(os.path.normpath(doc.archive_path))
+            else:
+                if not checksum == doc.archive_checksum:
+                    messages.append(SanityError(
+                        f"Checksum mismatch of document {doc.pk}. "
+                        f"Stored: {doc.checksum}, actual: {checksum}."
+                    ))
 
         if not doc.content:
             messages.append(SanityWarning(