net: add OCSP tests.

net/tools/testserver/asn1.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.
+
+# This file implements very minimal ASN.1, DER serialization.
+
+import types
+
+
+def ToDER(obj):
+  '''ToDER converts the given object into DER encoding'''
+  if type(obj) == types.NoneType:
+    # None turns into NULL
+    return TagAndLength(5, 0)
+  if type(obj) == types.StringType:
+    # Strings are PRINTABLESTRING
+    return TagAndLength(19, len(obj)) + obj
+  if type(obj) == types.BooleanType:
+    val = "\x00"
+    if obj:
+      val = "\xff"
+    return TagAndLength(1, 1) + val
+  if type(obj) == types.IntType or type(obj) == types.LongType:
+    big_endian = []
+    val = obj
+    while val != 0:
+      big_endian.append(val & 0xff)
+      val >>= 8
+
+    if len(big_endian) == 0 or big_endian[-1] >= 128:
+      big_endian.append(0)
+
+    big_endian.reverse()
+    return TagAndLength(2, len(big_endian)) + ToBytes(big_endian)
+
+  return obj.ToDER()
+
+
+def ToBytes(array_of_bytes):
+  '''ToBytes converts the array of byte values into a binary string'''
+  return ''.join([chr(x) for x in array_of_bytes])
+
+def TagAndLength(tag, length):
+  der = [tag]
+  if length < 128:
+    der.append(length)
+  elif length < 256:
+    der.append(0x81)
+    der.append(length)
+  elif length < 65535:
+    der.append(0x82)
+    der.append(length >> 8)
+    der.append(length & 0xff)
+  else:
+    assert False
+
+  return ToBytes(der)
+
+
+class Raw(object):
+  '''Raw contains raw DER encoded bytes that are used verbatim'''
+  def __init__(self, der):
+    self.der = der
+
+  def ToDER(self):
+    return self.der
+
+
+class Explicit(object):
+  '''Explicit prepends an explicit tag'''
+  def __init__(self, tag, child):
+    self.tag = tag
+    self.child = child
+
+  def ToDER(self):
+    der = ToDER(self.child)
+    tag = self.tag
+    tag |= 0x80 # content specific
+    tag |= 0x20 # complex
+    return TagAndLength(tag, len(der)) + der
+
+
+class ENUMERATED(object):
+  def __init__(self, value):
+    self.value = value
+
+  def ToDER(self):
+    return TagAndLength(10, 1) + chr(self.value)
+
+
+class SEQUENCE(object):
+  def __init__(self, children):
+    self.children = children
+
+  def ToDER(self):
+    der = ''.join([ToDER(x) for x in self.children])
+    return TagAndLength(0x30, len(der)) + der
+
+
+class SET(object):
+  def __init__(self, children):
+    self.children = children
+
+  def ToDER(self):
+    der = ''.join([ToDER(x) for x in self.children])
+    return TagAndLength(0x31, len(der)) + der
+
+
+class OCTETSTRING(object):
+  def __init__(self, val):
+    self.val = val
+
+  def ToDER(self):
+    return TagAndLength(4, len(self.val)) + self.val
+
+
+class OID(object):
+  def __init__(self, parts):
+    self.parts = parts
+
+  def ToDER(self):
+    if len(self.parts) < 2 or self.parts[0] > 6 or self.parts[1] >= 40:
+      assert False
+
+    der = [self.parts[0]*40 + self.parts[1]]
+    for x in self.parts[2:]:
+      if x == 0:
+        der.append(0)
+      else:
+        octets = []
+        while x != 0:
+          v = x & 0x7f
+          if len(octets) > 0:
+            v |= 0x80
+          octets.append(v)
+          x >>= 7
+        octets.reverse()
+        der = der + octets
+
+    return TagAndLength(6, len(der)) + ToBytes(der)
+
+
+class UTCTime(object):
+  def __init__(self, time_str):
+    self.time_str = time_str
+
+  def ToDER(self):
+    return TagAndLength(23, len(self.time_str)) + self.time_str
+
+
+class GeneralizedTime(object):
+  def __init__(self, time_str):
+    self.time_str = time_str
+
+  def ToDER(self):
+    return TagAndLength(24, len(self.time_str)) + self.time_str
+
+
+class BitString(object):
+  def __init__(self, bits):
+    self.bits = bits
+
+  def ToDER(self):
+    return TagAndLength(3, 1 + len(self.bits)) + "\x00" + self.bits