Allow setting of user and device policies in functional tests

chrome/test/pyautolib/asn1der.py

+# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Helper module for ASN.1/DER encoding."""
+
+import binascii
+import struct
+
+# Tags as defined by ASN.1.
+INTEGER = 2
+BIT_STRING = 3
+NULL = 5
+OBJECT_IDENTIFIER = 6
+SEQUENCE = 0x30
+
+
+def Data(tag, data):
+  """Generic type-length-value encoder.
+
+  Args:
+    tag: the tag.
+    data: the data for the given tag.
+
+  Returns:
+    encoded TLV value.
+  """
+  if len(data) == 0:
+    return struct.pack(">BB", tag, 0);
+  assert len(data) <= 0xffff;
+  return struct.pack(">BBH", tag, 0x82, len(data)) + data;
+
+
+def Integer(value):
+  """Encodes an integer.
+
+  Args:
+    value: the long value.
+
+  Returns:
+    encoded TLV value.
+  """
+  data = '%x' % value
+  return Data(INTEGER, binascii.unhexlify('00' + '0' * (len(data) % 2) + data))
+
+
+def Bitstring(value):
+  """Encodes a bit string.
+
+  Args:
+    value: a string holding the binary data.
+
+  Returns:
+    encoded TLV value.
+  """
+  return Data(BIT_STRING, '\x00' + value)
+
+
+def Sequence(values):
+  """Encodes a sequence of other values.
+
+  Args:
+    values: the list of values, must be strings holding already encoded data.
+
+  Returns:
+    encoded TLV value.
+  """
+  return Data(SEQUENCE, ''.join(values))