~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005 by Canonical Ltd

#   Authors: Robert Collins <robert.collins@canonical.com>

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""GPG signing and checking logic."""

import errno

import os

import subprocess

from bzrlib import (

    errors,

    trace,

    )

class DisabledGPGStrategy(object):

    """A GPG Strategy that makes everything fail."""

    def __init__(self, ignored):

        """Real strategies take a configuration."""

    def sign(self, content):

        raise errors.SigningFailed('Signing is disabled.')

class LoopbackGPGStrategy(object):

    """A GPG Strategy that acts like 'cat' - data is just passed through."""

    def __init__(self, ignored):

        """Real strategies take a configuration."""

    def sign(self, content):

        return content

def _set_gpg_tty():

    tty = os.environ.get('TTY')

    if tty is not None:

        os.environ['GPG_TTY'] = tty

        trace.mutter('setting GPG_TTY=%s', tty)

    else:

        # This is not quite worthy of a warning, because some people

        # don't need GPG_TTY to be set. But it is worthy of a big mark

        # in ~/.bzr.log, so that people can debug it if it happens to them

        trace.mutter('** Env var TTY empty, cannot set GPG_TTY.'

                     '  Is TTY exported?')

class GPGStrategy(object):

    """GPG Signing and checking facilities."""

    def _command_line(self):

        return [self._config.gpg_signing_command(), '--clearsign']

    def __init__(self, config):

        self._config = config

    def sign(self, content):

        try:

            process = subprocess.Popen(self._command_line(),

                                       stdin=subprocess.PIPE,

                                       stdout=subprocess.PIPE,

                                       preexec_fn=_set_gpg_tty)

            try:

                result = process.communicate(content)[0]

                if process.returncode is None:

                    process.wait()

                if process.returncode != 0:

                    raise errors.SigningFailed(self._command_line())

                return result

            except OSError, e:

                if e.errno == errno.EPIPE:

                    raise errors.SigningFailed(self._command_line())

                else:

                    raise

        except ValueError:

            # bad subprocess parameters, should never happen.

            raise

        except OSError, e:

            if e.errno == errno.ENOENT:

                # gpg is not installed

                raise errors.SigningFailed(self._command_line())

            else:

                raise