Add initial poc for RSA Accumulator snapshots: repo side

This commit uses a custom python implementation of Miller-Rabin
that we will want to replace with a well-maintained library.

It does not include efficient updates to the RSA Accumulator

Signed-off-by: Marina Moore <mnm678@gmail.com>

Author: mnm678

tests/test_repository_lib.py

@@ -467,62 +467,36 @@ def test_generate_targets_metadata(self):
                                          False, use_existing_fileinfo=True)
 
 
-  def test_build_merkle_tree(self):
+  def test_build_rsa_acc(self):
     temporary_directory = tempfile.mkdtemp(dir=self.temporary_directory)
     storage_backend = securesystemslib.storage.FilesystemBackend()
     version = 1
 
-    # Test building the tree one node at a time to verify the hashes
+    # Test an rsa accumulator with a few nodes to verify the output
 
     test_nodes = {}
     test_nodes['file1'] = tuf.formats.make_metadata_fileinfo(5, None, None)
 
-    root_1, leaves = repo_lib._build_merkle_tree(test_nodes)
-    repo_lib._write_merkle_paths(root_1, leaves, storage_backend,
-        temporary_directory, version)
-
-    file_path = os.path.join(temporary_directory, 'file1-snapshot.json')
-    self.assertTrue(os.path.exists(file_path))
-
-    file_path = os.path.join(temporary_directory, '1.file1-snapshot.json')
-    self.assertTrue(os.path.exists(file_path))
-
-    test_nodes['file2'] = tuf.formats.make_metadata_fileinfo(5, None, None)
-    root_2, leaves = repo_lib._build_merkle_tree(test_nodes)
-
-    self.assertEqual(root_2.left.digest, root_1.digest)
 
-    test_nodes['file3'] = tuf.formats.make_metadata_fileinfo(5, None, None)
-    test_nodes['file4'] = tuf.formats.make_metadata_fileinfo(5, None, None)
-
-    root_3, leaves = repo_lib._build_merkle_tree(test_nodes)
-
-    self.assertEqual(root_3.left.digest, root_2.digest)
-
-    test_nodes['file5'] = tuf.formats.make_metadata_fileinfo(5, None, None)
-
-    root_4, leaves = repo_lib._build_merkle_tree(test_nodes)
-
-    repo_lib._write_merkle_paths(root_4, leaves, storage_backend,
-        temporary_directory, version + 1)
-
-    self.assertEqual(root_4.left.digest, root_3.digest)
+    root_1, leaves = repo_lib._build_rsa_acc(test_nodes)
+    repo_lib._write_rsa_leaves(root_1, leaves, storage_backend,
+        temporary_directory, version)
 
     # Ensure that the paths are written to the directory
     file_path = os.path.join(temporary_directory, 'file1-snapshot.json')
     self.assertTrue(os.path.exists(file_path))
 
-    file_path = os.path.join(temporary_directory, '2.file1-snapshot.json')
+    file_path = os.path.join(temporary_directory, '1.file1-snapshot.json')
     self.assertTrue(os.path.exists(file_path))
 
-    # repo_lib.print_merkle_tree(root_4)
+    self.assertEqual(root_1, 5)
 
     test_nodes = {}
     test_nodes['targets'] = tuf.formats.make_metadata_fileinfo(1, None, None)
     test_nodes['role1'] = tuf.formats.make_metadata_fileinfo(1, None, None)
     test_nodes['role2'] = tuf.formats.make_metadata_fileinfo(1, None, None)
 
-    root, leaves = repo_lib._build_merkle_tree(test_nodes)
+    root, leaves = repo_lib._build_rsa_acc(test_nodes)
 
 
 

tests/test_repository_tool.py

@@ -255,20 +255,20 @@ def test_writeall(self):
     # Verify that status() does not raise an exception.
     repository.status()
 
-    # Test writeall with generating a snapshot merkle tree
+    # Test writeall with generating a snapshot RSA accumulator
     repository.mark_dirty(['role1', 'targets', 'root', 'snapshot', 'timestamp'])
-    repository.writeall(snapshot_merkle=True)
+    repository.writeall(rsa_acc=True)
 
-    # Were the merkle snapshots written?
+    # Were the RSA proof snapshots written?
     targets_snapshot_filepath = os.path.join(metadata_directory,
         'targets-snapshot.json')
     targets_snapshot = securesystemslib.util.load_json_file(targets_snapshot_filepath)
-    tuf.formats.SNAPSHOT_MERKLE_SCHEMA.check_match(targets_snapshot)
+    tuf.formats.SNAPSHOT_RSA_ACC_SCHEMA.check_match(targets_snapshot)
 
     # Does timestamp have the root hash?
     timestamp_filepath = os.path.join(metadata_directory, 'timestamp.json')
     timestamp = securesystemslib.util.load_json_file(timestamp_filepath)
-    timestamp['signed']['merkle_root']
+    timestamp['signed']['rsa_acc']
 
     # Verify that status() does not raise
     # 'tuf.exceptions.InsufficientKeysError' if a top-level role
@@ -512,7 +512,7 @@ def test_get_filepaths_in_directory(self):
     expected_files = []
     for filepath in ['1.root.json', 'root.json', 'targets.json',
         'snapshot.json', 'timestamp.json', 'role1.json', 'role2.json',
-        'targets-snapshot.json', 'timestamp-merkle.json',
+        'targets-snapshot.json', 'timestamp-rsa.json',
         'role1-snapshot.json', 'role2-snapshot.json']:
       expected_files.append(os.path.abspath(os.path.join(
           'repository_data', 'repository', 'metadata', filepath)))

tuf/formats.py

@@ -366,11 +366,10 @@
   targets = FILEDICT_SCHEMA,
   delegations = SCHEMA.Optional(DELEGATIONS_SCHEMA))
 
-SNAPSHOT_MERKLE_SCHEMA = SCHEMA.Object(
+SNAPSHOT_RSA_ACC_SCHEMA = SCHEMA.Object(
   leaf_contents = SCHEMA.OneOf([VERSIONINFO_SCHEMA,
                               METADATA_FILEINFO_SCHEMA]),
-  merkle_path = SCHEMA.DictOf(key_schema=SCHEMA.AnyString(), value_schema=HASH_SCHEMA),
-  path_directions = SCHEMA.DictOf(key_schema=SCHEMA.AnyString(), value_schema=SCHEMA.Integer()))
+  rsa_acc_proof = SCHEMA.AnyString())
 
 # Snapshot role: indicates the latest versions of all metadata (except
 # timestamp).
@@ -390,7 +389,7 @@
   version = METADATAVERSION_SCHEMA,
   expires = securesystemslib.formats.ISO8601_DATETIME_SCHEMA,
   meta = FILEINFODICT_SCHEMA,
-  merkle_root = SCHEMA.Optional(HASH_SCHEMA))
+  rsa_acc = SCHEMA.Optional(HASH_SCHEMA))
 
 
 # project.cfg file: stores information about the project in a json dictionary