py/dkps/dkps.py

# Copyright 2015 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""The DRM Keys Provisioning Server (DKPS) implementation."""

# TODO(littlecvr): Implement "without filter mode", which lets OEM encrypts DRM
#                  keys directly with ODM's public key, and the key server
#                  merely stores them without knowing anything about them.

import argparse
import hashlib
import imp
import json
import logging
import logging.config
import os
import shutil
import SimpleXMLRPCServer
import sqlite3
import textwrap

import gnupg


SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
FILTERS_DIR = os.path.join(SCRIPT_DIR, 'filters')
PARSERS_DIR = os.path.join(SCRIPT_DIR, 'parsers')
CREATE_DATABASE_SQL_FILE_PATH = os.path.join(
    SCRIPT_DIR, 'sql', 'create_database.sql')

DEFAULT_BIND_ADDR = '0.0.0.0'  # all addresses
DEFAULT_BIND_PORT = 5438

DEFAULT_DATABASE_FILE_NAME = 'dkps.db'
DEFAULT_GNUPG_DIR_NAME = 'gnupg'
DEFAULT_LOG_FILE_NAME = 'dkps.log'

DEFAULT_LOGGING_CONFIG = {
    'version': 1,
    'formatters': {
        'default': {
            'format': '%(asctime)s:%(levelname)s:%(funcName)s:'
                      '%(lineno)d:%(message)s'}},
    'handlers': {
        'file': {
            'class': 'logging.handlers.RotatingFileHandler',
            'formatter': 'default',
            'filename': DEFAULT_LOG_FILE_NAME,
            'maxBytes': 1024 * 1024,  # 1M
            'backupCount': 3},
        'console': {
            'class': 'logging.StreamHandler',
            'formatter': 'default',
            'stream': 'ext://sys.stdout'}},
    'root': {
        'level': 'INFO',
        # only log to file by default, but also log to console if invoked
        # directly from the command line
        'handlers': ['file'] + ['console'] if __name__ == '__main__' else []}}


class ProjectNotFoundException(ValueError):
  """Raised when no project was found in the database."""
  pass


class InvalidUploaderException(ValueError):
  """Raised when the signature of the uploader can't be verified."""
  pass


class InvalidRequesterException(ValueError):
  """Raised when the signature of the requester can't be verified."""
  pass


def GetSQLite3Connection(database_file_path):
  """Returns a tuple of SQLite3's (connection, cursor) to database_file_path.

  If the connection has been created before, it is returned directly. If it's
  not, this function creates the connection, ensures that the foreign key
  constraint is enabled, and returns.

  Args:
    database_file_path: path to the SQLite3 database file.
  """
  database_file_path = os.path.realpath(database_file_path)

  # Return if the connection to database_file_path has been created before.
  try:
    connection = GetSQLite3Connection.connection_dict[database_file_path]
    return (connection, connection.cursor())
  except KeyError:
    pass
  except AttributeError:
    GetSQLite3Connection.connection_dict = {}

  # Create connection.
  connection = sqlite3.connect(database_file_path)
  connection.row_factory = sqlite3.Row
  cursor = connection.cursor()

  # Enable foreign key constraint since SQLite3 disables it by default.
  cursor.execute('PRAGMA foreign_keys = ON')
  # Check if foreign key constraint is enabled.
  cursor.execute('PRAGMA foreign_keys')
  if cursor.fetchone()[0] != 1:
    raise RuntimeError('Failed to enable SQLite3 foreign key constraint')

  GetSQLite3Connection.connection_dict[database_file_path] = connection

  return (connection, cursor)


class DRMKeysProvisioningServer(object):
  """The DRM Keys Provisioning Server (DKPS) class."""

  def __init__(self, database_file_path, gnupg_homedir):
    """DKPS constructor.

    Args:
      database_file_path: path to the SQLite3 database file.
      gnupg_homedir: path to the GnuPG home directory.
    """
    self.database_file_path = database_file_path
    self.gnupg_homedir = gnupg_homedir

    if not os.path.isdir(self.gnupg_homedir):
      self.gpg = None
    else:
      self.gpg = gnupg.GPG(gnupghome=self.gnupg_homedir)

    if not os.path.isfile(self.database_file_path):
      self.db_connection, self.db_cursor = (None, None)
    else:
      self.db_connection, self.db_cursor = GetSQLite3Connection(
          self.database_file_path)

  def Initialize(self, gpg_gen_key_args_dict=None, server_key_file_path=None):
    """Creates the SQLite3 database and GnuPG home, and imports, or generates a
    GPG key for the server to use.

    Args:
      gpg_gen_key_args_dict: will be passed directly as the keyword arguments to
          python-gnupg's gen_key() function if server_key_file_path is None.
          Can be used to customize the key generator process, such as key_type,
          key_length, etc. See python-gnupg's doc for what can be customized.
      server_key_file_path: path to the server key to use. If not None, the
          system will simply import this key and use it as the server key; if
          None, the system will generate a new key.

    Raises:
      RuntimeError is the database and GnuPG home have already been initialized.
    """
    # Create GPG instance and database connection.
    self.gpg = gnupg.GPG(gnupghome=self.gnupg_homedir)
    self.db_connection, self.db_cursor = GetSQLite3Connection(
        self.database_file_path)

    # If any key exists, the system has already been initialized.
    if self.gpg.list_keys():
      raise RuntimeError('Already initialized')

    if server_key_file_path:  # use existing key
      # TODO(littlecvr): make sure the server key doesn't have passphrase.
      server_key_fingerprint, _ = self._ImportGPGKey(server_key_file_path)
    else:  # generate a new GPG key
      if gpg_gen_key_args_dict is None:
        gpg_gen_key_args_dict = {}
      if 'name_real' not in gpg_gen_key_args_dict:
        gpg_gen_key_args_dict['name_real'] = 'DKPS Server'
      if 'name_email' not in gpg_gen_key_args_dict:
        gpg_gen_key_args_dict['name_email'] = 'chromeos-factory-dkps@google.com'
      if 'name_comment' not in gpg_gen_key_args_dict:
        gpg_gen_key_args_dict['name_comment'] = 'DRM Keys Provisioning Server'
      key_input_data = self.gpg.gen_key_input(**gpg_gen_key_args_dict)
      server_key_fingerprint = self.gpg.gen_key(key_input_data).fingerprint

    # Create and set up the schema of the database.
    with open(CREATE_DATABASE_SQL_FILE_PATH) as f:
      create_database_sql = f.read()
    with self.db_connection:
      self.db_cursor.executescript(create_database_sql)

    # Record the server key fingerprint.
    with self.db_connection:
      self.db_cursor.execute(
          'INSERT INTO settings (key, value) VALUES (?, ?)',
          ('server_key_fingerprint', server_key_fingerprint))

  def Destroy(self):
    """Destroys the database and GnuPG home directory.

    This is the opposite of Initialize(). It essentially removes the SQLite3
    database file and GnuPG home directory.
    """
    # Remove database.
    if self.db_connection:
      self.db_connection.close()
    if os.path.exists(self.database_file_path):
      os.remove(self.database_file_path)

    # Remove GnuPG home.
    if self.gpg:
      self.gpg = None
    if os.path.exists(self.gnupg_homedir):
      shutil.rmtree(self.gnupg_homedir)

  def AddProject(self, name, uploader_key_file_path, requester_key_file_path,
                 parser_module_file_name, filter_module_file_name=None):
    """Adds a project.

    Args:
      name: name of the project, must be unique.
      uploader_key_file_path: path to the OEM's public key file.
      requester_key_file_path: path to the ODM's public key file.
      parser_module_file_name: file name of the parser python module.
      filter_module_file_name: file name of the filter python module.

    Raises:
      ValueError if either the uploader's or requester's key are imported (which
      means they are used by another project).
    """
    # Try to load the parser and filter modules.
    self._LoadParserModule(parser_module_file_name)
    if filter_module_file_name is not None:
      self._LoadFilterModule(filter_module_file_name)

    # Try to import uploader and requester keys and add project info into the
    # database, if failed at any step, delete imported keys.
    uploader_key_fingerprint, requester_key_fingerprint = (None, None)
    uploader_key_already_exists, requester_key_already_exists = (False, False)
    try:
      uploader_key_fingerprint, uploader_key_already_exists = (
          self._ImportGPGKey(uploader_key_file_path))
      if uploader_key_already_exists:
        raise ValueError('Uploader key already exists')
      requester_key_fingerprint, requester_key_already_exists = (
          self._ImportGPGKey(requester_key_file_path))
      if requester_key_already_exists:
        raise ValueError('Requester key already exists')
      with self.db_connection:
        self.db_cursor.execute(
            'INSERT INTO projects ('
            '    name, uploader_key_fingerprint, requester_key_fingerprint, '
            '    parser_module_file_name, filter_module_file_name) '
            'VALUES (?, ?, ?, ?, ?)',
            (name, uploader_key_fingerprint, requester_key_fingerprint,
             parser_module_file_name, filter_module_file_name))
    except BaseException:
      if not uploader_key_already_exists and uploader_key_fingerprint:
        self.gpg.delete_keys(uploader_key_fingerprint)
      if not requester_key_already_exists and requester_key_fingerprint:
        self.gpg.delete_keys(requester_key_fingerprint)
      raise

  def UpdateProject(self, name, uploader_key_file_path=None,
                    requester_key_file_path=None, filter_module_file_name=None):
    """Updates a project.

    Args:
      name: name of the project, must be unique.
      uploader_key_file_path: path to the OEM's public key file.
      requester_key_file_path: path to the ODM's public key file.
      filter_module_file_name: file name of the filter python module.

    Raises:
      RuntimeError if SQLite3 can't update the project row (for any reason).
    """
    # Try to load the filter module.
    if filter_module_file_name is not None:
      self._LoadFilterModule(filter_module_file_name)

    project = self._FetchProjectByName(name)

    # Try to import uploader and requester keys and add project info into the
    # database, if failed at any step, delete any newly imported keys.
    uploader_key_fingerprint, requester_key_fingerprint = (None, None)
    old_uploader_key_fingerprint = project['uploader_key_fingerprint']
    old_requester_key_fingerprint = project['requester_key_fingerprint']
    same_uploader_key, same_requester_key = (True, True)
    try:
      sql_set_clause_list = ['filter_module_file_name = ?']
      sql_parameters = [filter_module_file_name]

      if uploader_key_file_path:
        uploader_key_fingerprint, same_uploader_key = self._ImportGPGKey(
            uploader_key_file_path)
        sql_set_clause_list.append('uploader_key_fingerprint = ?')
        sql_parameters.append(uploader_key_fingerprint)

      if requester_key_file_path:
        requester_key_fingerprint, same_requester_key = self._ImportGPGKey(
            uploader_key_file_path)
        sql_set_clause_list.append('requester_key_fingerprint = ?')
        sql_parameters.append(requester_key_fingerprint)

      sql_set_clause = ','.join(sql_set_clause_list)
      sql_parameters.append(name)
      with self.db_connection:
        self.db_cursor.execute(
            'UPDATE projects SET %s WHERE name = ?' % sql_set_clause,
            tuple(sql_parameters))
      if self.db_cursor.rowcount != 1:
        raise RuntimeError('Failed to update project %s' % name)
    except BaseException:
      if not same_uploader_key and uploader_key_fingerprint:
        self.gpg.delete_keys(uploader_key_fingerprint)
      if not same_requester_key and requester_key_fingerprint:
        self.gpg.delete_keys(requester_key_fingerprint)
      raise

    if not same_uploader_key:
      self.gpg.delete_keys(old_uploader_key_fingerprint)
    if not same_requester_key:
      self.gpg.delete_keys(old_requester_key_fingerprint)

  def RemoveProject(self, name):
    """Removes a project.

    Args:
      name: the name of the project specified when added.
    """
    project = self._FetchProjectByName(name)

    self.gpg.delete_keys(project['uploader_key_fingerprint'])
    self.gpg.delete_keys(project['requester_key_fingerprint'])

    with self.db_connection:
      self.db_cursor.execute(
          'DELETE FROM drm_keys WHERE project_name = ?', (name,))
      self.db_cursor.execute('DELETE FROM projects WHERE name = ?', (name,))

  def ListProjects(self):
    """Lists all projects."""
    self.db_cursor.execute('SELECT * FROM projects ORDER BY name ASC')
    return self.db_cursor.fetchall()

  def Upload(self, encrypted_serialized_drm_keys):
    """Uploads a list of DRM keys to the server. This is an atomic operation. It
    will either succeed and save all the keys, or fail and save no keys.

    Args:
      encrypted_serialized_drm_keys: the serialized DRM keys signed by the
          uploader and encrypted by the server's public key.

    Raises:
      InvalidUploaderException if the signature of the uploader can not be
      verified.
    """
    decrypted_obj = self.gpg.decrypt(encrypted_serialized_drm_keys)
    project = self._FetchProjectByUploaderKeyFingerprint(
        decrypted_obj.fingerprint)
    serialized_drm_keys = decrypted_obj.data

    # Pass to the parse function.
    parser_module = self._LoadParserModule(project['parser_module_file_name'])
    drm_key_list = parser_module.Parse(serialized_drm_keys)

    drm_key_hash_list = []
    for drm_key in drm_key_list:
      drm_key_hash_list.append(hashlib.sha1(json.dumps(drm_key)).hexdigest())

    # Pass to the filter function if needed.
    if project['filter_module_file_name']:  # filter module can be null
      filter_module = self._LoadFilterModule(project['filter_module_file_name'])
      filtered_drm_key_list = filter_module.Filter(drm_key_list)
    else:
      # filter module is optional
      filtered_drm_key_list = drm_key_list

    # Fetch server key for signing.
    server_key_fingerprint = self._FetchServerKeyFingerprint()

    # Sign and encrypt each key by server's private key and requester's public
    # key, respectively.
    encrypted_serialized_drm_key_list = []
    requester_key_fingerprint = project['requester_key_fingerprint']
    for drm_key in filtered_drm_key_list:
      encrypted_obj = self.gpg.encrypt(
          json.dumps(drm_key), requester_key_fingerprint,
          always_trust=True, sign=server_key_fingerprint)
      encrypted_serialized_drm_key_list.append(encrypted_obj.data)

    # Insert into the database.
    with self.db_connection:
      self.db_cursor.executemany(
          'INSERT INTO drm_keys ('
          '    project_name, drm_key_hash, encrypted_drm_key) '
          'VALUES (?, ?, ?)',
          zip([project['name']] * len(encrypted_serialized_drm_key_list),
              drm_key_hash_list, encrypted_serialized_drm_key_list))

  def AvailableKeyCount(self, requester_signature):
    """Queries the number of remaining keys.

    Args:
      requester_signature: a message signed by the requester. Since the server
          doesn't need any additional info from the requester, the requester can
          simply sign a random string and send it here.

    Returns:
      The number of remaining keys that can be requested.

    Raises:
      InvalidRequesterException if the signature of the requester can not be
      verified.
    """
    verified = self.gpg.verify(requester_signature)
    if not verified:
      raise InvalidRequesterException(
          'Invalid requester, check your signing key')

    project = self._FetchProjectByRequesterKeyFingerprint(verified.fingerprint)

    self.db_cursor.execute(
        'SELECT COUNT(*) AS available_key_count FROM drm_keys '
        'WHERE project_name = ? AND device_serial_number IS NULL',
        (project['name'],))
    return self.db_cursor.fetchone()['available_key_count']

  def Request(self, encrypted_device_serial_number):
    """Requests a DRM key by device serial number.

    Args:
      encrypted_device_serial_number: the device serial number signed by the
          requester and encrypted by the server's public key.

    Raises:
      InvalidRequesterException if the signature of the requester can not be
      verified. RuntimeError if no available keys left in the database.
    """
    decrypted_obj = self.gpg.decrypt(encrypted_device_serial_number)
    project = self._FetchProjectByRequesterKeyFingerprint(
        decrypted_obj.fingerprint)
    device_serial_number = decrypted_obj.data

    def FetchDRMKeyByDeviceSerialNumber(project_name, device_serial_number):
      self.db_cursor.execute(
          'SELECT * FROM drm_keys WHERE project_name = ? AND '
          'device_serial_number = ?',
          (project_name, device_serial_number))
      return self.db_cursor.fetchone()

    row = FetchDRMKeyByDeviceSerialNumber(project['name'], device_serial_number)
    if row:  # the SN has already paired
      return row['encrypted_drm_key']

    # Find an unpaired key.
    with self.db_connection:
      # SQLite3 does not support using LIMIT clause in UPDATE statement by
      # default, unless SQLITE_ENABLE_UPDATE_DELETE_LIMIT flag is defined during
      # compilation. Since this script may be deployed on partner's computer,
      # we'd better assume they don't have this flag on.
      self.db_cursor.execute(
          'UPDATE drm_keys SET device_serial_number = ? '
          'WHERE id = (SELECT id FROM drm_keys WHERE project_name = ? AND '
          '            device_serial_number IS NULL LIMIT 1)',
          (device_serial_number, project['name']))
    if self.db_cursor.rowcount != 1:  # insufficient keys
      raise RuntimeError(
          'Insufficient DRM keys, ask for the OEM to upload more')

    row = FetchDRMKeyByDeviceSerialNumber(project['name'], device_serial_number)
    if row:
      return row['encrypted_drm_key']
    else:
      raise RuntimeError('Failed to find paired DRM key')

  def ListenForever(self, ip, port):
    """Starts the XML RPC server waiting for commands.

    Args:
      ip: IP to bind.
      port: port to bind.
    """
    class Server(SimpleXMLRPCServer.SimpleXMLRPCServer):
      def _dispatch(self, method, params):
        # Catch exceptions and log them. Without this, SimpleXMLRPCServer simply
        # output the error message to stdout, and we won't be able to see what
        # happened in the log file.
        logging.info('%s called', method)
        try:
          result = SimpleXMLRPCServer.SimpleXMLRPCServer._dispatch(
              self, method, params)
          logging.warning('MAO %r', result)
          return result
        except BaseException as e:
          logging.exception(e)
          raise

    server = Server((ip, port), allow_none=True)

    server.register_introspection_functions()
    server.register_function(self.AvailableKeyCount)
    server.register_function(self.Upload)
    server.register_function(self.Request)

    server.serve_forever()

  def _ImportGPGKey(self, key_file_path):
    """Imports a GPG key from a file.

    Args:
      key_file_path: path to the GPG key file.

    Returns:
      A tuple (key_fingerprint, key_already_exists). The 1st element is the
      imported key's fingerprint, and the 2nd element is True if the key was
      already in the database before importing, False otherwise.
    """
    with open(key_file_path) as f:
      import_results = self.gpg.import_keys(f.read())
    key_already_exists = (import_results.imported == 0)
    key_fingerprint = import_results.fingerprints[0]
    return (key_fingerprint, key_already_exists)

  def _LoadFilterModule(self, filter_module_file_name):
    """Loads the filter module.

    Args:
      filter_module_file_name: file name of the filter module in FILTERS_DIR.

    Returns:
      The loaded filter module on success.

    Raises:
      Exception if failed, see imp.load_source()'s doc for what could be raised.
    """
    return imp.load_source(
        'filter_module', os.path.join(FILTERS_DIR, filter_module_file_name))

  def _LoadParserModule(self, parser_module_file_name):
    """Loads the parser module.

    Args:
      parser_module_file_name: file name of the parser module in PARSERS_DIR.

    Returns:
      The loaded parser module on success.

    Raises:
      Exception if failed, see imp.load_source()'s doc for what could be raised.
    """
    return imp.load_source(
        'parser_module', os.path.join(PARSERS_DIR, parser_module_file_name))

  def _FetchServerKeyFingerprint(self):
    """Returns the server GPG key's fingerprint."""
    self.db_cursor.execute(
        "SELECT * FROM settings WHERE key = 'server_key_fingerprint'")
    row = self.db_cursor.fetchone()
    if not row:
      raise ValueError('Server key fingerprint not exists')
    return row['value']

  def _FetchOneProject(self, name=None,  # pylint: disable=W0613
                       uploader_key_fingerprint=None,  # pylint: disable=W0613
                       requester_key_fingerprint=None,  # pylint: disable=W0613
                       exception_type=None, error_msg=None):
    """Fetches the project by name, uploader key fingerprint, or requester key
    fingerprint.

    This function combines the name, uploader_key_fingerprint,
    requester_key_fingerprint conditions (if not None) with the AND operator,
    and tries to fetch one project from the database.

    Args:
      name: name of the project.
      uploader_key_fingerprint: uploader key fingerprint of the project.
      requester_key_fingerprint: requester key fingerprint of the project.
      exception_type: if no project was found and exception_type is not None,
          raise exception_type with error_msg.
      error_msg: if no project was found and exception_type is not None, raise
          exception_type with error_msg.

    Returns:
      A project that matches the name, uploader_key_fingerprint, and
      requester_key_fingerprint conditiions.

    Raises:
      exception_type with error_msg if not project was found.
    """
    where_clause_list = []
    params = []
    local_vars = locals()
    for param_name in ['name', 'uploader_key_fingerprint',
                       'requester_key_fingerprint']:
      if local_vars[param_name] is not None:
        where_clause_list.append('%s = ?' % param_name)
        params.append(locals()[param_name])
    if not where_clause_list:
      raise ValueError('No conditions given to fetch the project')
    where_clause = 'WHERE ' + ' AND '.join(where_clause_list)

    self.db_cursor.execute(
        'SELECT * FROM projects %s' % where_clause, tuple(params))
    project = self.db_cursor.fetchone()

    if not project and exception_type:
      raise exception_type(error_msg)

    return project

  def _FetchProjectByName(self, name):
    return self._FetchOneProject(
        name=name, exception_type=ProjectNotFoundException,
        error_msg=('Project %s not found' % name))

  def _FetchProjectByUploaderKeyFingerprint(self, uploader_key_fingerprint):
    return self._FetchOneProject(
        uploader_key_fingerprint=uploader_key_fingerprint,
        exception_type=InvalidUploaderException,
        error_msg='Invalid uploader, check your signing key')

  def _FetchProjectByRequesterKeyFingerprint(self, requester_key_fingerprint):
    return self._FetchOneProject(
        requester_key_fingerprint=requester_key_fingerprint,
        exception_type=InvalidRequesterException,
        error_msg='Invalid requester, check your signing key')


def _ParseArguments():
  parser = argparse.ArgumentParser()
  parser.add_argument(
      '-d', '--database_file_path',
      default=os.path.join(SCRIPT_DIR, DEFAULT_DATABASE_FILE_NAME),
      help='path to the SQLite3 database file, default to "dkps.db" in the '
           'same directory of this script')
  parser.add_argument(
      '-g', '--gnupg_homedir',
      default=os.path.join(SCRIPT_DIR, DEFAULT_GNUPG_DIR_NAME),
      help='path to the GnuGP home directory, default to "gnupg" in the same '
           'directory of this script')
  parser.add_argument(
      '-l', '--log_file_path',
      default=os.path.join(SCRIPT_DIR, DEFAULT_LOG_FILE_NAME),
      help='path to the log file, default to "dkps.log" in the same directory '
           'of this script')
  subparsers = parser.add_subparsers(dest='command')

  parser_add = subparsers.add_parser('add', help='adds a new project')
  parser_add.add_argument('-n', '--name', required=True,
                          help='name of the new project')
  parser_add.add_argument('-u', '--uploader_key_file_path', required=True,
                          help="path to the uploader's public key file")
  parser_add.add_argument('-r', '--requester_key_file_path', required=True,
                          help="path to the requester's public key file")
  parser_add.add_argument('-p', '--parser_module_file_name', required=True,
                          help='file name of the parser module')
  parser_add.add_argument('-f', '--filter_module_file_name', default=None,
                          help='file name of the filter module')

  subparsers.add_parser('destroy', help='destroys the database')

  parser_update = subparsers.add_parser('update',
                                        help='updates an existing project')
  parser_update.add_argument('-n', '--name', required=True,
                             help='name of the project')
  parser_update.add_argument('-u', '--uploader_key_file_path', default=None,
                             help="path to the uploader's public key file")
  parser_update.add_argument('-r', '--requester_key_file_path', default=None,
                             help="path to the requester's public key file")
  parser_update.add_argument('-f', '--filter_module_file_name', default=None,
                             help='file name of the filter module')

  parser_init = subparsers.add_parser('init', help='initializes the database')
  parser_init.add_argument(
      '-g', '--gpg_gen_key_args', action='append', nargs=2, default={},
      help='arguments to use when generating GPG key for server')
  parser_init.add_argument(
      '-s', '--server_key_file_path', default=None,
      help="path to the server's private key file")

  subparsers.add_parser('list', help='lists all projects')

  parser_listen = subparsers.add_parser(
      'listen', help='starts the server, waiting for upload or request keys')
  parser_listen.add_argument(
      '--ip', default=DEFAULT_BIND_ADDR,
      help='IP to bind, default to %s' % DEFAULT_BIND_ADDR)
  parser_listen.add_argument(
      '--port', type=int, default=DEFAULT_BIND_PORT,
      help='port to listen, default to %s' % DEFAULT_BIND_PORT)

  parser_rm = subparsers.add_parser('rm', help='removes an existing project')
  parser_rm.add_argument('-n', '--name', required=True,
                         help='name of the project to remove')

  return parser.parse_args()


def main():
  args = _ParseArguments()

  logging_config = DEFAULT_LOGGING_CONFIG
  logging_config['handlers']['file']['filename'] = args.log_file_path
  logging.config.dictConfig(logging_config)

  dkps = DRMKeysProvisioningServer(args.database_file_path, args.gnupg_homedir)
  if args.command == 'init':
    # Convert from command line arguments to a dict.
    gpg_gen_key_args_dict = {}
    for pair in args.gpg_gen_key_args:
      gpg_gen_key_args_dict[pair[0]] = pair[1]
    dkps.Initialize(gpg_gen_key_args_dict, args.server_key_file_path)
  elif args.command == 'destroy':
    message = (
        'This action will remove all projects and keys information and is NOT '
        'recoverable! Are you sure? (y/N)')
    answer = raw_input(textwrap.fill(message, 80) + ' ')
    if answer.lower() != 'y' and answer.lower() != 'yes':
      print 'OK, nothing will be removed.'
    else:
      print 'Removing all projects and keys information...',
      dkps.Destroy()
      print 'done.'
  elif args.command == 'listen':
    dkps.ListenForever(args.ip, args.port)
  elif args.command == 'list':
    print dkps.ListProjects()
  elif args.command == 'add':
    dkps.AddProject(
        args.name, args.uploader_key_file_path, args.requester_key_file_path,
        args.parser_module_file_name, args.filter_module_file_name)
  elif args.command == 'update':
    dkps.UpdateProject(
        args.name, args.uploader_key_file_path, args.requester_key_file_path,
        args.filter_module_file_name)
  elif args.command == 'rm':
    dkps.RemoveProject(args.name)
  else:
    raise ValueError('Unknown command %s' % args.command)


if __name__ == '__main__':
  main()