# Authors:
#   Endi S. Dewata <edewata@redhat.com>
#
# Copyright (C) 2015  Red Hat
# see file 'COPYING' for use and warranty information
#
# 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 3 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, see <http://www.gnu.org/licenses/>.

from __future__ import print_function

import base64
import getpass
import io
import json
import os
import sys

from cryptography.fernet import Fernet, InvalidToken
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.hazmat.primitives.serialization import load_pem_public_key,\
    load_pem_private_key

import nss.nss as nss

from ipaclient.frontend import MethodOverride
from ipalib.frontend import Local, Method, Object
from ipalib import errors
from ipalib import Bytes, Flag, Str
from ipalib.plugable import Registry
from ipalib import _
from ipaplatform.paths import paths


def validated_read(argname, filename, mode='r', encoding=None):
    """Read file and catch errors

    IOError and UnicodeError (for text files) are turned into a
    ValidationError
    """
    try:
        with io.open(filename, mode=mode, encoding=encoding) as f:
            data = f.read()
    except IOError as exc:
        raise errors.ValidationError(
            name=argname,
            error=_("Cannot read file '%(filename)s': %(exc)s") % {
                'filename': filename, 'exc': exc.args[1]
                }
        )
    except UnicodeError as exc:
        raise errors.ValidationError(
            name=argname,
            error=_("Cannot decode file '%(filename)s': %(exc)s") % {
                'filename': filename, 'exc': exc
                }
        )
    return data


register = Registry()

MAX_VAULT_DATA_SIZE = 2**20  # = 1 MB


def get_new_password():
    """
    Gets new password from user and verify it.
    """
    while True:
        password = getpass.getpass('New password: ').decode(
            sys.stdin.encoding)
        password2 = getpass.getpass('Verify password: ').decode(
            sys.stdin.encoding)

        if password == password2:
            return password

        print('  ** Passwords do not match! **')


def get_existing_password():
    """
    Gets existing password from user.
    """
    return getpass.getpass('Password: ').decode(sys.stdin.encoding)


def generate_symmetric_key(password, salt):
    """
    Generates symmetric key from password and salt.
    """
    kdf = PBKDF2HMAC(
        algorithm=hashes.SHA256(),
        length=32,
        salt=salt,
        iterations=100000,
        backend=default_backend()
    )

    return base64.b64encode(kdf.derive(password.encode('utf-8')))


def encrypt(data, symmetric_key=None, public_key=None):
    """
    Encrypts data with symmetric key or public key.
    """
    if symmetric_key:
        fernet = Fernet(symmetric_key)
        return fernet.encrypt(data)

    elif public_key:
        public_key_obj = load_pem_public_key(
            data=public_key,
            backend=default_backend()
        )
        return public_key_obj.encrypt(
            data,
            padding.OAEP(
                mgf=padding.MGF1(algorithm=hashes.SHA1()),
                algorithm=hashes.SHA1(),
                label=None
            )
        )


def decrypt(data, symmetric_key=None, private_key=None):
    """
    Decrypts data with symmetric key or public key.
    """
    if symmetric_key:
        try:
            fernet = Fernet(symmetric_key)
            return fernet.decrypt(data)
        except InvalidToken:
            raise errors.AuthenticationError(
                message=_('Invalid credentials'))

    elif private_key:
        try:
            private_key_obj = load_pem_private_key(
                data=private_key,
                password=None,
                backend=default_backend()
            )
            return private_key_obj.decrypt(
                data,
                padding.OAEP(
                    mgf=padding.MGF1(algorithm=hashes.SHA1()),
                    algorithm=hashes.SHA1(),
                    label=None
                )
            )
        except AssertionError:
            raise errors.AuthenticationError(
                message=_('Invalid credentials'))


@register(no_fail=True)
class _fake_vault(Object):
    name = 'vault'


@register(no_fail=True)
class _fake_vault_add_internal(Method):
    name = 'vault_add_internal'
    NO_CLI = True


@register()
class vault_add(Local):
    __doc__ = _('Create a new vault.')

    takes_options = (
        Str(
            'password?',
            cli_name='password',
            doc=_('Vault password'),
        ),
        Str(  # TODO: use File parameter
            'password_file?',
            cli_name='password_file',
            doc=_('File containing the vault password'),
        ),
        Str(  # TODO: use File parameter
            'public_key_file?',
            cli_name='public_key_file',
            doc=_('File containing the vault public key'),
        ),
    )

    @property
    def NO_CLI(self):
        return self.api.Command.vault_add_internal.NO_CLI

    def get_args(self):
        for arg in self.api.Command.vault_add_internal.args():
            yield arg
        for arg in super(vault_add, self).get_args():
            yield arg

    def get_options(self):
        for option in self.api.Command.vault_add_internal.options():
            if option.name not in ('ipavaultsalt', 'version'):
                yield option
        for option in super(vault_add, self).get_options():
            yield option

    def _iter_output(self):
        return self.api.Command.vault_add_internal.output()

    def forward(self, *args, **options):

        vault_type = options.get('ipavaulttype')
        password = options.get('password')
        password_file = options.get('password_file')
        public_key = options.get('ipavaultpublickey')
        public_key_file = options.get('public_key_file')

        # don't send these parameters to server
        if 'password' in options:
            del options['password']
        if 'password_file' in options:
            del options['password_file']
        if 'public_key_file' in options:
            del options['public_key_file']

        if vault_type != u'symmetric' and (password or password_file):
            raise errors.MutuallyExclusiveError(
                reason=_('Password can be specified only for '
                         'symmetric vault')
            )

        if vault_type != u'asymmetric' and (public_key or public_key_file):
            raise errors.MutuallyExclusiveError(
                reason=_('Public key can be specified only for '
                         'asymmetric vault')
            )

        if self.api.env.in_server:
            backend = self.api.Backend.ldap2
        else:
            backend = self.api.Backend.rpcclient
        if not backend.isconnected():
            backend.connect()

        if vault_type == u'standard':

            pass

        elif vault_type == u'symmetric':

            # get password
            if password and password_file:
                raise errors.MutuallyExclusiveError(
                    reason=_('Password specified multiple times'))

            elif password:
                pass

            elif password_file:
                password = validated_read('password-file',
                                          password_file,
                                          encoding='utf-8')
                password = password.rstrip('\n')

            else:
                password = get_new_password()

            # generate vault salt
            options['ipavaultsalt'] = os.urandom(16)

        elif vault_type == u'asymmetric':

            # get new vault public key
            if public_key and public_key_file:
                raise errors.MutuallyExclusiveError(
                    reason=_('Public key specified multiple times'))

            elif public_key:
                pass

            elif public_key_file:
                public_key = validated_read('public-key-file',
                                            public_key_file,
                                            mode='rb')

                # store vault public key
                options['ipavaultpublickey'] = public_key

            else:
                raise errors.ValidationError(
                    name='ipavaultpublickey',
                    error=_('Missing vault public key'))

            # validate public key and prevent users from accidentally
            # sending a private key to the server.
            try:
                load_pem_public_key(
                    data=public_key,
                    backend=default_backend()
                )
            except ValueError as e:
                raise errors.ValidationError(
                    name='ipavaultpublickey',
                    error=_('Invalid or unsupported vault public key: %s') % e,
                )

        # create vault
        response = self.api.Command.vault_add_internal(*args, **options)

        # prepare parameters for archival
        opts = options.copy()
        if 'description' in opts:
            del opts['description']
        if 'ipavaulttype' in opts:
            del opts['ipavaulttype']

        if vault_type == u'symmetric':
            opts['password'] = password
            del opts['ipavaultsalt']

        elif vault_type == u'asymmetric':
            del opts['ipavaultpublickey']

        # archive blank data
        self.api.Command.vault_archive(*args, **opts)

        return response


@register(no_fail=True)
class _fake_vault_mod_internal(Method):
    name = 'vault_mod_internal'
    NO_CLI = True


@register()
class vault_mod(Local):
    __doc__ = _('Modify a vault.')

    takes_options = (
        Flag(
            'change_password?',
            doc=_('Change password'),
        ),
        Str(
            'old_password?',
            cli_name='old_password',
            doc=_('Old vault password'),
        ),
        Str(  # TODO: use File parameter
            'old_password_file?',
            cli_name='old_password_file',
            doc=_('File containing the old vault password'),
        ),
        Str(
            'new_password?',
            cli_name='new_password',
            doc=_('New vault password'),
        ),
        Str(  # TODO: use File parameter
            'new_password_file?',
            cli_name='new_password_file',
            doc=_('File containing the new vault password'),
        ),
        Bytes(
            'private_key?',
            cli_name='private_key',
            doc=_('Old vault private key'),
        ),
        Str(  # TODO: use File parameter
            'private_key_file?',
            cli_name='private_key_file',
            doc=_('File containing the old vault private key'),
        ),
        Str(  # TODO: use File parameter
            'public_key_file?',
            cli_name='public_key_file',
            doc=_('File containing the new vault public key'),
        ),
    )

    @property
    def NO_CLI(self):
        return self.api.Command.vault_mod_internal.NO_CLI

    def get_args(self):
        for arg in self.api.Command.vault_mod_internal.args():
            yield arg
        for arg in super(vault_mod, self).get_args():
            yield arg

    def get_options(self):
        for option in self.api.Command.vault_mod_internal.options():
            if option.name not in ('ipavaultsalt', 'version'):
                yield option
        for option in super(vault_mod, self).get_options():
            yield option

    def _iter_output(self):
        return self.api.Command.vault_mod_internal.output()

    def forward(self, *args, **options):

        vault_type = options.pop('ipavaulttype', False)
        salt = options.pop('ipavaultsalt', False)
        change_password = options.pop('change_password', False)

        old_password = options.pop('old_password', None)
        old_password_file = options.pop('old_password_file', None)
        new_password = options.pop('new_password', None)
        new_password_file = options.pop('new_password_file', None)

        old_private_key = options.pop('private_key', None)
        old_private_key_file = options.pop('private_key_file', None)
        new_public_key = options.pop('ipavaultpublickey', None)
        new_public_key_file = options.pop('public_key_file', None)

        if self.api.env.in_server:
            backend = self.api.Backend.ldap2
        else:
            backend = self.api.Backend.rpcclient
        if not backend.isconnected():
            backend.connect()

        # determine the vault type based on parameters specified
        if vault_type:
            pass

        elif change_password or new_password or new_password_file or salt:
            vault_type = u'symmetric'

        elif new_public_key or new_public_key_file:
            vault_type = u'asymmetric'

        # if vault type is specified, retrieve existing secret
        if vault_type:
            opts = options.copy()
            opts.pop('description', None)

            opts['password'] = old_password
            opts['password_file'] = old_password_file
            opts['private_key'] = old_private_key
            opts['private_key_file'] = old_private_key_file

            response = self.api.Command.vault_retrieve(*args, **opts)
            data = response['result']['data']

        opts = options.copy()

        # if vault type is specified, update crypto attributes
        if vault_type:
            opts['ipavaulttype'] = vault_type

            if vault_type == u'standard':
                opts['ipavaultsalt'] = None
                opts['ipavaultpublickey'] = None

            elif vault_type == u'symmetric':
                if salt:
                    opts['ipavaultsalt'] = salt
                else:
                    opts['ipavaultsalt'] = os.urandom(16)

                opts['ipavaultpublickey'] = None

            elif vault_type == u'asymmetric':

                # get new vault public key
                if new_public_key and new_public_key_file:
                    raise errors.MutuallyExclusiveError(
                        reason=_('New public key specified multiple times'))

                elif new_public_key:
                    pass

                elif new_public_key_file:
                    new_public_key = validated_read('public_key_file',
                                                    new_public_key_file,
                                                    mode='rb')

                else:
                    raise errors.ValidationError(
                        name='ipavaultpublickey',
                        error=_('Missing new vault public key'))

                opts['ipavaultsalt'] = None
                opts['ipavaultpublickey'] = new_public_key

        response = self.api.Command.vault_mod_internal(*args, **opts)

        # if vault type is specified, rearchive existing secret
        if vault_type:
            opts = options.copy()
            opts.pop('description', None)

            opts['data'] = data
            opts['password'] = new_password
            opts['password_file'] = new_password_file
            opts['override_password'] = True

            self.api.Command.vault_archive(*args, **opts)

        return response


@register(override=True, no_fail=True)
class vaultconfig_show(MethodOverride):
    def forward(self, *args, **options):

        file = options.get('transport_out')

        # don't send these parameters to server
        if 'transport_out' in options:
            del options['transport_out']

        response = super(vaultconfig_show, self).forward(*args, **options)

        if file:
            with open(file, 'w') as f:
                f.write(response['result']['transport_cert'])

        return response


@register(no_fail=True)
class _fake_vault_archive_internal(Method):
    name = 'vault_archive_internal'
    NO_CLI = True


@register()
class vault_archive(Local):
    __doc__ = _('Archive data into a vault.')

    takes_options = (
        Bytes(
            'data?',
            doc=_('Binary data to archive'),
        ),
        Str(  # TODO: use File parameter
            'in?',
            doc=_('File containing data to archive'),
        ),
        Str(
            'password?',
            cli_name='password',
            doc=_('Vault password'),
        ),
        Str(  # TODO: use File parameter
            'password_file?',
            cli_name='password_file',
            doc=_('File containing the vault password'),
        ),
        Flag(
            'override_password?',
            doc=_('Override existing password'),
        ),
    )

    @property
    def NO_CLI(self):
        return self.api.Command.vault_archive_internal.NO_CLI

    def get_args(self):
        for arg in self.api.Command.vault_archive_internal.args():
            yield arg
        for arg in super(vault_archive, self).get_args():
            yield arg

    def get_options(self):
        for option in self.api.Command.vault_archive_internal.options():
            if option.name not in ('nonce',
                                   'session_key',
                                   'vault_data',
                                   'version'):
                yield option
        for option in super(vault_archive, self).get_options():
            yield option

    def _iter_output(self):
        return self.api.Command.vault_archive_internal.output()

    def forward(self, *args, **options):

        name = args[-1]

        data = options.get('data')
        input_file = options.get('in')

        password = options.get('password')
        password_file = options.get('password_file')

        override_password = options.pop('override_password', False)

        # don't send these parameters to server
        if 'data' in options:
            del options['data']
        if 'in' in options:
            del options['in']
        if 'password' in options:
            del options['password']
        if 'password_file' in options:
            del options['password_file']

        # get data
        if data and input_file:
            raise errors.MutuallyExclusiveError(
                reason=_('Input data specified multiple times'))

        elif data:
            if len(data) > MAX_VAULT_DATA_SIZE:
                raise errors.ValidationError(name="data", error=_(
                    "Size of data exceeds the limit. Current vault data size "
                    "limit is %(limit)d B")
                    % {'limit': MAX_VAULT_DATA_SIZE})

        elif input_file:
            try:
                stat = os.stat(input_file)
            except OSError as exc:
                raise errors.ValidationError(name="in", error=_(
                    "Cannot read file '%(filename)s': %(exc)s")
                    % {'filename': input_file, 'exc': exc.args[1]})
            if stat.st_size > MAX_VAULT_DATA_SIZE:
                raise errors.ValidationError(name="in", error=_(
                    "Size of data exceeds the limit. Current vault data size "
                    "limit is %(limit)d B")
                    % {'limit': MAX_VAULT_DATA_SIZE})
            data = validated_read('in', input_file, mode='rb')

        else:
            data = ''

        if self.api.env.in_server:
            backend = self.api.Backend.ldap2
        else:
            backend = self.api.Backend.rpcclient
        if not backend.isconnected():
            backend.connect()

        # retrieve vault info
        vault = self.api.Command.vault_show(*args, **options)['result']

        vault_type = vault['ipavaulttype'][0]

        if vault_type == u'standard':

            encrypted_key = None

        elif vault_type == u'symmetric':

            # get password
            if password and password_file:
                raise errors.MutuallyExclusiveError(
                    reason=_('Password specified multiple times'))

            elif password:
                pass

            elif password_file:
                password = validated_read('password-file',
                                          password_file,
                                          encoding='utf-8')
                password = password.rstrip('\n')

            else:
                if override_password:
                    password = get_new_password()
                else:
                    password = get_existing_password()

            if not override_password:
                # verify password by retrieving existing data
                opts = options.copy()
                opts['password'] = password
                try:
                    self.api.Command.vault_retrieve(*args, **opts)
                except errors.NotFound:
                    pass

            salt = vault['ipavaultsalt'][0]

            # generate encryption key from vault password
            encryption_key = generate_symmetric_key(password, salt)

            # encrypt data with encryption key
            data = encrypt(data, symmetric_key=encryption_key)

            encrypted_key = None

        elif vault_type == u'asymmetric':

            public_key = vault['ipavaultpublickey'][0].encode('utf-8')

            # generate encryption key
            encryption_key = base64.b64encode(os.urandom(32))

            # encrypt data with encryption key
            data = encrypt(data, symmetric_key=encryption_key)

            # encrypt encryption key with public key
            encrypted_key = encrypt(encryption_key, public_key=public_key)

        else:
            raise errors.ValidationError(
                name='vault_type',
                error=_('Invalid vault type'))

        # initialize NSS database
        current_dbdir = paths.IPA_NSSDB_DIR
        nss.nss_init(current_dbdir)

        # retrieve transport certificate
        config = self.api.Command.vaultconfig_show()['result']
        transport_cert_der = config['transport_cert']
        nss_transport_cert = nss.Certificate(transport_cert_der)

        # generate session key
        mechanism = nss.CKM_DES3_CBC_PAD
        slot = nss.get_best_slot(mechanism)
        key_length = slot.get_best_key_length(mechanism)
        session_key = slot.key_gen(mechanism, None, key_length)

        # wrap session key with transport certificate
        # pylint: disable=no-member
        public_key = nss_transport_cert.subject_public_key_info.public_key
        # pylint: enable=no-member
        wrapped_session_key = nss.pub_wrap_sym_key(mechanism,
                                                   public_key,
                                                   session_key)

        options['session_key'] = wrapped_session_key.data

        nonce_length = nss.get_iv_length(mechanism)
        nonce = nss.generate_random(nonce_length)
        options['nonce'] = nonce

        vault_data = {}
        vault_data[u'data'] = base64.b64encode(data).decode('utf-8')

        if encrypted_key:
            vault_data[u'encrypted_key'] = base64.b64encode(encrypted_key)\
                .decode('utf-8')

        json_vault_data = json.dumps(vault_data)

        # wrap vault_data with session key
        iv_si = nss.SecItem(nonce)
        iv_param = nss.param_from_iv(mechanism, iv_si)

        encoding_ctx = nss.create_context_by_sym_key(mechanism,
                                                     nss.CKA_ENCRYPT,
                                                     session_key,
                                                     iv_param)

        wrapped_vault_data = encoding_ctx.cipher_op(json_vault_data)\
            + encoding_ctx.digest_final()

        options['vault_data'] = wrapped_vault_data

        return self.api.Command.vault_archive_internal(*args, **options)


@register(no_fail=True)
class _fake_vault_retrieve_internal(Method):
    name = 'vault_retrieve_internal'
    NO_CLI = True


@register()
class vault_retrieve(Local):
    __doc__ = _('Retrieve a data from a vault.')

    takes_options = (
        Str(
            'out?',
            doc=_('File to store retrieved data'),
        ),
        Str(
            'password?',
            cli_name='password',
            doc=_('Vault password'),
        ),
        Str(  # TODO: use File parameter
            'password_file?',
            cli_name='password_file',
            doc=_('File containing the vault password'),
        ),
        Bytes(
            'private_key?',
            cli_name='private_key',
            doc=_('Vault private key'),
        ),
        Str(  # TODO: use File parameter
            'private_key_file?',
            cli_name='private_key_file',
            doc=_('File containing the vault private key'),
        ),
    )

    has_output_params = (
        Bytes(
            'data',
            label=_('Data'),
        ),
    )

    @property
    def NO_CLI(self):
        return self.api.Command.vault_retrieve_internal.NO_CLI

    def get_args(self):
        for arg in self.api.Command.vault_retrieve_internal.args():
            yield arg
        for arg in super(vault_retrieve, self).get_args():
            yield arg

    def get_options(self):
        for option in self.api.Command.vault_retrieve_internal.options():
            if option.name not in ('session_key', 'version'):
                yield option
        for option in super(vault_retrieve, self).get_options():
            yield option

    def _iter_output(self):
        return self.api.Command.vault_retrieve_internal.output()

    def forward(self, *args, **options):

        name = args[-1]

        output_file = options.get('out')

        password = options.get('password')
        password_file = options.get('password_file')
        private_key = options.get('private_key')
        private_key_file = options.get('private_key_file')

        # don't send these parameters to server
        if 'out' in options:
            del options['out']
        if 'password' in options:
            del options['password']
        if 'password_file' in options:
            del options['password_file']
        if 'private_key' in options:
            del options['private_key']
        if 'private_key_file' in options:
            del options['private_key_file']

        if self.api.env.in_server:
            backend = self.api.Backend.ldap2
        else:
            backend = self.api.Backend.rpcclient
        if not backend.isconnected():
            backend.connect()

        # retrieve vault info
        vault = self.api.Command.vault_show(*args, **options)['result']

        vault_type = vault['ipavaulttype'][0]

        # initialize NSS database
        current_dbdir = paths.IPA_NSSDB_DIR
        nss.nss_init(current_dbdir)

        # retrieve transport certificate
        config = self.api.Command.vaultconfig_show()['result']
        transport_cert_der = config['transport_cert']
        nss_transport_cert = nss.Certificate(transport_cert_der)

        # generate session key
        mechanism = nss.CKM_DES3_CBC_PAD
        slot = nss.get_best_slot(mechanism)
        key_length = slot.get_best_key_length(mechanism)
        session_key = slot.key_gen(mechanism, None, key_length)

        # wrap session key with transport certificate
        # pylint: disable=no-member
        public_key = nss_transport_cert.subject_public_key_info.public_key
        # pylint: enable=no-member
        wrapped_session_key = nss.pub_wrap_sym_key(mechanism,
                                                   public_key,
                                                   session_key)

        # send retrieval request to server
        options['session_key'] = wrapped_session_key.data

        response = self.api.Command.vault_retrieve_internal(*args, **options)

        result = response['result']
        nonce = result['nonce']

        # unwrap data with session key
        wrapped_vault_data = result['vault_data']

        iv_si = nss.SecItem(nonce)
        iv_param = nss.param_from_iv(mechanism, iv_si)

        decoding_ctx = nss.create_context_by_sym_key(mechanism,
                                                     nss.CKA_DECRYPT,
                                                     session_key,
                                                     iv_param)

        json_vault_data = decoding_ctx.cipher_op(wrapped_vault_data)\
            + decoding_ctx.digest_final()

        vault_data = json.loads(json_vault_data)
        data = base64.b64decode(vault_data[u'data'].encode('utf-8'))

        encrypted_key = None

        if 'encrypted_key' in vault_data:
            encrypted_key = base64.b64decode(vault_data[u'encrypted_key']
                                             .encode('utf-8'))

        if vault_type == u'standard':

            pass

        elif vault_type == u'symmetric':

            salt = vault['ipavaultsalt'][0]

            # get encryption key from vault password
            if password and password_file:
                raise errors.MutuallyExclusiveError(
                    reason=_('Password specified multiple times'))

            elif password:
                pass

            elif password_file:
                password = validated_read('password-file',
                                          password_file,
                                          encoding='utf-8')
                password = password.rstrip('\n')

            else:
                password = get_existing_password()

            # generate encryption key from password
            encryption_key = generate_symmetric_key(password, salt)

            # decrypt data with encryption key
            data = decrypt(data, symmetric_key=encryption_key)

        elif vault_type == u'asymmetric':

            # get encryption key with vault private key
            if private_key and private_key_file:
                raise errors.MutuallyExclusiveError(
                    reason=_('Private key specified multiple times'))

            elif private_key:
                pass

            elif private_key_file:
                private_key = validated_read('private-key-file',
                                             private_key_file,
                                             mode='rb')

            else:
                raise errors.ValidationError(
                    name='private_key',
                    error=_('Missing vault private key'))

            # decrypt encryption key with private key
            encryption_key = decrypt(encrypted_key, private_key=private_key)

            # decrypt data with encryption key
            data = decrypt(data, symmetric_key=encryption_key)

        else:
            raise errors.ValidationError(
                name='vault_type',
                error=_('Invalid vault type'))

        if output_file:
            with open(output_file, 'w') as f:
                f.write(data)

        else:
            response['result'] = {'data': data}

        return response