Add scripts to generate simple test data for certificate verification.

net/data/verify_certificate_chain_unittest/openssl_conf.py

+#!/usr/bin/python
+# Copyright (c) 2015 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 contains helpers for representing, manipulating, and writing
+OpenSSL configuration files [1]
+
+Configuration files are simply a collection of name=value "properties", which
+are grouped into "sections".
+
+[1] https://www.openssl.org/docs/manmaster/apps/config.html
+"""
+
+class Property(object):
+  """Represents a key/value pair in OpenSSL .cnf files.
+
+  Names and values are not quoted in any way, so callers need to pass the text
+  exactly as it should be written to the file (leading and trailing whitespace
+  doesn't matter).
+
+  For instance:
+      baseConstraints = critical, CA:false
+
+  Could be represented by a Property where:
+    name = 'baseConstraints'
+    value = 'critical, CA:false'
+  """
+  def __init__(self, name, value):
+    self.name = name
+    self.value = value
+
+
+  def WriteTo(self, out):
+    """Outputs this property to .cnf file."""
+    out.write('%s = %s\n' % (self.name, self.value))
+
+
+class Section(object):
+  """Represents a section in OpenSSL. For instance:
+      [CA_root]
+      preserve = true
+
+  Could be represented by a Section where:
+    name = 'CA_root'
+    properties = [Property('preserve', 'true')]
+  """
+  def __init__(self, name):
+    self.name = name
+    self.properties = []
+
+
+  def EnsurePropertyNameNotDuplicated(self, name):
+    """Raises an exception of there is more than 1 property named |name|."""
+    count = 0
+    for prop in self.properties:
+      if prop.name == name:
+        count += 1

[mattm, 2015/11/02 19:40:39]

If you want to get into python tricks:
count = sum(1 for prop in self.properties if prop.name == name)

[eroman, 2015/11/02 20:51:43]

Thanks, I decided not to use that (since I find it harder to read as a python
n00b).

+    if count > 1:
+      raise Exception('Duplicate property: %s' % (name))
+
+
+  def SetProperty(self, name, value):
+    """Replaces, adds, or removes a Property from the Section:
+
+      - If |value| is None, then this is equivalent to calling
+        RemoveProperty(name)
+      - If there is an existing property matching |name| then its value is
+        replaced with |value|
+      - If there are no properties matching |name| then a new one is added at
+        the end of the section
+
+    It is expected that there is AT MOST 1 property with the given name. If
+    that is not the case then this function will raise an error."""
+
+    if value is None:
+      self.RemoveProperty(name)
+      return
+
+    self.EnsurePropertyNameNotDuplicated(name)
+
+    for prop in self.properties:
+      if prop.name == name:
+        prop.value = value
+        return
+
+    self.AddProperty(name, value)
+
+
+  def AddProperty(self, name, value):
+    """Adds a property (allows duplicates)"""
+    self.properties.append(Property(name, value))
+
+
+  def RemoveProperty(self, name):
+    """Removes the property with the indicated name, if it exists.
+
+    It is expected that there is AT MOST 1 property with the given name. If
+    that is not the case then this function will raise an error."""
+    self.EnsurePropertyNameNotDuplicated(name)
+
+    for i in range(len(self.properties)):
+      if self.properties[i].name == name:
+        self.properties.pop(i)
+        return
+
+
+  def WriteTo(self, out):
+    """Outputs the section in the format used by .cnf files"""
+    out.write('[%s]\n' % (self.name))
+    for prop in self.properties:
+      prop.WriteTo(out)
+    out.write('\n')
+
+
+class Config(object):
+  """Represents a .cnf (configuration) file in OpenSSL"""
+  def __init__(self):
+    self.sections = []
+
+
+  def GetSection(self, name):
+    """Gets or creates a section with the given name."""
+    for section in self.sections:
+      if section.name == name:
+        return section
+    new_section = Section(name)
+    self.sections.append(new_section)
+    return new_section
+
+
+  def WriteToFile(self, path):
+    """Outputs the Config to a .cnf files."""
+    with open(path, 'w') as out:
+      for section in self.sections:
+        section.WriteTo(out)