Support of file digest in manifest file

Per sol-004, section 4.3.2, the csar manifest file should include the
digest of individual files contained in the package. This patch lays the
foundation of that support.

- Added content check of manifest file
- Added support of generating local file digest in manifest file

Change-Id: If575012d319e6f6aa0e2259e7405d8a2b6f8f338
Issue-ID: VNFSDK-174
Signed-off-by: Lianhao Lu <lianhao.lu@intel.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/vnfsdk_pkgtools/packager/utils.py b/vnfsdk_pkgtools/packager/utils.py
new file mode 100644
index 0000000..78c7b0f
--- /dev/null
+++ b/vnfsdk_pkgtools/packager/utils.py
@@ -0,0 +1,33 @@
+# Copyright (c) 2018 Intel Corp Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+
+import hashlib
+import os
+
+def _hash_value_for_file(f, hash_function, block_size=2**20):
+    while True:
+        data = f.read(block_size)
+        if not data:
+            break
+        hash_function.update(data)
+
+    return hash_function.hexdigest()
+
+
+def cal_file_hash(root, path, algo):
+    with open(os.path.join(root, path), 'rb') as fp:
+        h = hashlib.new(algo)
+        return _hash_value_for_file(fp, h)
+