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# -------------------------------------------------------------------------
# Copyright (c) Microsoft. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# --------------------------------------------------------------------------
from datetime import date
from ._common_conversion import (
_sign_string,
_to_str,
)
from ._constants import DEFAULT_X_MS_VERSION
from ._serialization import (
url_quote,
_to_utc_datetime,
)
class SharedAccessSignature(object):
'''
Provides a factory for creating account access
signature tokens with an account name and account key. Users can either
use the factory or can construct the appropriate service and use the
generate_*_shared_access_signature method directly.
'''
def __init__(self, account_name, account_key, x_ms_version=DEFAULT_X_MS_VERSION):
'''
:param str account_name:
The storage account name used to generate the shared access signatures.
:param str account_key:
The access key to generate the shares access signatures.
:param str x_ms_version:
The service version used to generate the shared access signatures.
'''
self.account_name = account_name
self.account_key = account_key
self.x_ms_version = x_ms_version
def generate_account(self, services, resource_types, permission, expiry, start=None,
ip=None, protocol=None):
'''
Generates a shared access signature for the account.
Use the returned signature with the sas_token parameter of the service
or to create a new account object.
:param Services services:
Specifies the services accessible with the account SAS. You can
combine values to provide access to more than one service.
:param ResourceTypes resource_types:
Specifies the resource types that are accessible with the account
SAS. You can combine values to provide access to more than one
resource type.
:param AccountPermissions permission:
The permissions associated with the shared access signature. The
user is restricted to operations allowed by the permissions.
Required unless an id is given referencing a stored access policy
which contains this field. This field must be omitted if it has been
specified in an associated stored access policy. You can combine
values to provide more than one permission.
:param expiry:
The time at which the shared access signature becomes invalid.
Required unless an id is given referencing a stored access policy
which contains this field. This field must be omitted if it has
been specified in an associated stored access policy. Azure will always
convert values to UTC. If a date is passed in without timezone info, it
is assumed to be UTC.
:type expiry: datetime or str
:param start:
The time at which the shared access signature becomes valid. If
omitted, start time for this call is assumed to be the time when the
storage service receives the request. Azure will always convert values
to UTC. If a date is passed in without timezone info, it is assumed to
be UTC.
:type start: datetime or str
:param str ip:
Specifies an IP address or a range of IP addresses from which to accept requests.
If the IP address from which the request originates does not match the IP address
or address range specified on the SAS token, the request is not authenticated.
For example, specifying sip=168.1.5.65 or sip=168.1.5.60-168.1.5.70 on the SAS
restricts the request to those IP addresses.
:param str protocol:
Specifies the protocol permitted for a request made. The default value
is https,http. See :class:`~azure.storage.common.models.Protocol` for possible values.
'''
sas = _SharedAccessHelper()
sas.add_base(permission, expiry, start, ip, protocol, self.x_ms_version)
sas.add_account(services, resource_types)
sas.add_account_signature(self.account_name, self.account_key)
return sas.get_token()
class _QueryStringConstants(object):
SIGNED_SIGNATURE = 'sig'
SIGNED_PERMISSION = 'sp'
SIGNED_START = 'st'
SIGNED_EXPIRY = 'se'
SIGNED_RESOURCE = 'sr'
SIGNED_IDENTIFIER = 'si'
SIGNED_IP = 'sip'
SIGNED_PROTOCOL = 'spr'
SIGNED_VERSION = 'sv'
SIGNED_CACHE_CONTROL = 'rscc'
SIGNED_CONTENT_DISPOSITION = 'rscd'
SIGNED_CONTENT_ENCODING = 'rsce'
SIGNED_CONTENT_LANGUAGE = 'rscl'
SIGNED_CONTENT_TYPE = 'rsct'
START_PK = 'spk'
START_RK = 'srk'
END_PK = 'epk'
END_RK = 'erk'
SIGNED_RESOURCE_TYPES = 'srt'
SIGNED_SERVICES = 'ss'
class _SharedAccessHelper(object):
def __init__(self):
self.query_dict = {}
def _add_query(self, name, val):
if val:
self.query_dict[name] = _to_str(val)
def add_base(self, permission, expiry, start, ip, protocol, x_ms_version):
if isinstance(start, date):
start = _to_utc_datetime(start)
if isinstance(expiry, date):
expiry = _to_utc_datetime(expiry)
self._add_query(_QueryStringConstants.SIGNED_START, start)
self._add_query(_QueryStringConstants.SIGNED_EXPIRY, expiry)
self._add_query(_QueryStringConstants.SIGNED_PERMISSION, permission)
self._add_query(_QueryStringConstants.SIGNED_IP, ip)
self._add_query(_QueryStringConstants.SIGNED_PROTOCOL, protocol)
self._add_query(_QueryStringConstants.SIGNED_VERSION, x_ms_version)
def add_resource(self, resource):
self._add_query(_QueryStringConstants.SIGNED_RESOURCE, resource)
def add_id(self, id):
self._add_query(_QueryStringConstants.SIGNED_IDENTIFIER, id)
def add_account(self, services, resource_types):
self._add_query(_QueryStringConstants.SIGNED_SERVICES, services)
self._add_query(_QueryStringConstants.SIGNED_RESOURCE_TYPES, resource_types)
def add_override_response_headers(self, cache_control,
content_disposition,
content_encoding,
content_language,
content_type):
self._add_query(_QueryStringConstants.SIGNED_CACHE_CONTROL, cache_control)
self._add_query(_QueryStringConstants.SIGNED_CONTENT_DISPOSITION, content_disposition)
self._add_query(_QueryStringConstants.SIGNED_CONTENT_ENCODING, content_encoding)
self._add_query(_QueryStringConstants.SIGNED_CONTENT_LANGUAGE, content_language)
self._add_query(_QueryStringConstants.SIGNED_CONTENT_TYPE, content_type)
def add_resource_signature(self, account_name, account_key, service, path):
def get_value_to_append(query):
return_value = self.query_dict.get(query) or ''
return return_value + '\n'
if path[0] != '/':
path = '/' + path
canonicalized_resource = '/' + service + '/' + account_name + path + '\n'
# Form the string to sign from shared_access_policy and canonicalized
# resource. The order of values is important.
string_to_sign = \
(get_value_to_append(_QueryStringConstants.SIGNED_PERMISSION) +
get_value_to_append(_QueryStringConstants.SIGNED_START) +
get_value_to_append(_QueryStringConstants.SIGNED_EXPIRY) +
canonicalized_resource +
get_value_to_append(_QueryStringConstants.SIGNED_IDENTIFIER) +
get_value_to_append(_QueryStringConstants.SIGNED_IP) +
get_value_to_append(_QueryStringConstants.SIGNED_PROTOCOL) +
get_value_to_append(_QueryStringConstants.SIGNED_VERSION))
if service == 'blob' or service == 'file':
string_to_sign += \
(get_value_to_append(_QueryStringConstants.SIGNED_CACHE_CONTROL) +
get_value_to_append(_QueryStringConstants.SIGNED_CONTENT_DISPOSITION) +
get_value_to_append(_QueryStringConstants.SIGNED_CONTENT_ENCODING) +
get_value_to_append(_QueryStringConstants.SIGNED_CONTENT_LANGUAGE) +
get_value_to_append(_QueryStringConstants.SIGNED_CONTENT_TYPE))
# remove the trailing newline
if string_to_sign[-1] == '\n':
string_to_sign = string_to_sign[:-1]
self._add_query(_QueryStringConstants.SIGNED_SIGNATURE,
_sign_string(account_key, string_to_sign))
def add_account_signature(self, account_name, account_key):
def get_value_to_append(query):
return_value = self.query_dict.get(query) or ''
return return_value + '\n'
string_to_sign = \
(account_name + '\n' +
get_value_to_append(_QueryStringConstants.SIGNED_PERMISSION) +
get_value_to_append(_QueryStringConstants.SIGNED_SERVICES) +
get_value_to_append(_QueryStringConstants.SIGNED_RESOURCE_TYPES) +
get_value_to_append(_QueryStringConstants.SIGNED_START) +
get_value_to_append(_QueryStringConstants.SIGNED_EXPIRY) +
get_value_to_append(_QueryStringConstants.SIGNED_IP) +
get_value_to_append(_QueryStringConstants.SIGNED_PROTOCOL) +
get_value_to_append(_QueryStringConstants.SIGNED_VERSION))
self._add_query(_QueryStringConstants.SIGNED_SIGNATURE,
_sign_string(account_key, string_to_sign))
def get_token(self):
return '&'.join(['{0}={1}'.format(n, url_quote(v)) for n, v in self.query_dict.items() if v is not None])
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