def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
python类safe_str_cmp()的实例源码
def validate_csrf(data, secret_key=None, time_limit=None, token_key=None):
"""Check if the given data is a valid CSRF token. This compares the given
signed token to the one stored in the session.
:param data: The signed CSRF token to be checked.
:param secret_key: Used to securely sign the token. Default is
``WTF_CSRF_SECRET_KEY`` or ``SECRET_KEY``.
:param time_limit: Number of seconds that the token is valid. Default is
``WTF_CSRF_TIME_LIMIT`` or 3600 seconds (60 minutes).
:param token_key: Key where token is stored in session for comparision.
Default is ``WTF_CSRF_FIELD_NAME`` or ``'csrf_token'``.
:raises ValidationError: Contains the reason that validation failed.
.. versionchanged:: 0.14
Raises ``ValidationError`` with a specific error message rather than
returning ``True`` or ``False``.
"""
secret_key = _get_config(
secret_key, 'WTF_CSRF_SECRET_KEY', current_app.secret_key,
message='A secret key is required to use CSRF.'
)
field_name = _get_config(
token_key, 'WTF_CSRF_FIELD_NAME', 'csrf_token',
message='A field name is required to use CSRF.'
)
time_limit = _get_config(
time_limit, 'WTF_CSRF_TIME_LIMIT', 3600, required=False
)
if not data:
raise ValidationError('The CSRF token is missing.')
if field_name not in session:
raise ValidationError('The CSRF session token is missing.')
s = URLSafeTimedSerializer(secret_key, salt='wtf-csrf-token')
try:
token = s.loads(data, max_age=time_limit)
except SignatureExpired:
raise ValidationError('The CSRF token has expired.')
except BadData:
raise ValidationError('The CSRF token is invalid.')
if not safe_str_cmp(session[field_name], token):
raise ValidationError('The CSRF tokens do not match.')
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def validate_csrf(data, secret_key=None, time_limit=None, token_key=None):
"""Check if the given data is a valid CSRF token. This compares the given
signed token to the one stored in the session.
:param data: The signed CSRF token to be checked.
:param secret_key: Used to securely sign the token. Default is
``WTF_CSRF_SECRET_KEY`` or ``SECRET_KEY``.
:param time_limit: Number of seconds that the token is valid. Default is
``WTF_CSRF_TIME_LIMIT`` or 3600 seconds (60 minutes).
:param token_key: Key where token is stored in session for comparision.
Default is ``WTF_CSRF_FIELD_NAME`` or ``'csrf_token'``.
:raises ValidationError: Contains the reason that validation failed.
.. versionchanged:: 0.14
Raises ``ValidationError`` with a specific error message rather than
returning ``True`` or ``False``.
"""
secret_key = _get_config(
secret_key, 'WTF_CSRF_SECRET_KEY', current_app.secret_key,
message='A secret key is required to use CSRF.'
)
field_name = _get_config(
token_key, 'WTF_CSRF_FIELD_NAME', 'csrf_token',
message='A field name is required to use CSRF.'
)
time_limit = _get_config(
time_limit, 'WTF_CSRF_TIME_LIMIT', 3600, required=False
)
if not data:
raise ValidationError('The CSRF token is missing.')
if field_name not in session:
raise ValidationError('The CSRF session token is missing.')
s = URLSafeTimedSerializer(secret_key, salt='wtf-csrf-token')
try:
token = s.loads(data, max_age=time_limit)
except SignatureExpired:
raise ValidationError('The CSRF token has expired.')
except BadData:
raise ValidationError('The CSRF token is invalid.')
if not safe_str_cmp(session[field_name], token):
raise ValidationError('The CSRF tokens do not match.')
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if not b'=' in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if not b'=' in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if not b'=' in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def validate_csrf(data, secret_key=None, time_limit=None):
"""Check if the given data is a valid csrf token.
:param data: The csrf token value to be checked.
:param secret_key: A secret key for mixing in the token,
default is Flask.secret_key.
:param time_limit: Check if the csrf token is expired.
default is True.
"""
if not data or '##' not in data:
return False
expires, hmac_csrf = data.split('##', 1)
if time_limit is None:
time_limit = current_app.config.get('WTF_CSRF_TIME_LIMIT', 3600)
if time_limit:
try:
expires = float(expires)
except:
return False
now = time.time()
if now > expires:
return False
if not secret_key:
secret_key = current_app.config.get(
'WTF_CSRF_SECRET_KEY', current_app.secret_key
)
if 'csrf_token' not in session:
return False
csrf_build = '%s%s' % (session['csrf_token'], expires)
hmac_compare = hmac.new(
to_bytes(secret_key),
to_bytes(csrf_build),
digestmod=hashlib.sha1
).hexdigest()
return safe_str_cmp(hmac_compare, hmac_csrf)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if not b'=' in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def unserialize(cls, string, secret_key):
"""Load the secure cookie from a serialized string.
:param string: the cookie value to unserialize.
:param secret_key: the secret key used to serialize the cookie.
:return: a new :class:`SecureCookie`.
"""
if isinstance(string, text_type):
string = string.encode('utf-8', 'replace')
if isinstance(secret_key, text_type):
secret_key = secret_key.encode('utf-8', 'replace')
try:
base64_hash, data = string.split(b'?', 1)
except (ValueError, IndexError):
items = ()
else:
items = {}
mac = hmac(secret_key, None, cls.hash_method)
for item in data.split(b'&'):
mac.update(b'|' + item)
if b'=' not in item:
items = None
break
key, value = item.split(b'=', 1)
# try to make the key a string
key = url_unquote_plus(key.decode('ascii'))
try:
key = to_native(key)
except UnicodeError:
pass
items[key] = value
# no parsing error and the mac looks okay, we can now
# sercurely unpickle our cookie.
try:
client_hash = base64.b64decode(base64_hash)
except TypeError:
items = client_hash = None
if items is not None and safe_str_cmp(client_hash, mac.digest()):
try:
for key, value in iteritems(items):
items[key] = cls.unquote(value)
except UnquoteError:
items = ()
else:
if '_expires' in items:
if time() > items['_expires']:
items = ()
else:
del items['_expires']
else:
items = ()
return cls(items, secret_key, False)
def validate_csrf(data, secret_key=None, time_limit=None):
"""Check if the given data is a valid csrf token.
:param data: The csrf token value to be checked.
:param secret_key: A secret key for mixing in the token,
default is Flask.secret_key.
:param time_limit: Check if the csrf token is expired.
default is True.
"""
if not data or '##' not in data:
return False
try:
expires, hmac_csrf = data.split('##', 1)
except ValueError:
return False # unpack error
if time_limit is None:
time_limit = current_app.config.get('WTF_CSRF_TIME_LIMIT', 3600)
if time_limit:
try:
expires = int(expires)
except ValueError:
return False
now = int(time.time())
if now > expires:
return False
if not secret_key:
secret_key = current_app.config.get(
'WTF_CSRF_SECRET_KEY', current_app.secret_key
)
if 'csrf_token' not in session:
return False
csrf_build = '%s%s' % (session['csrf_token'], expires)
hmac_compare = hmac.new(
to_bytes(secret_key),
to_bytes(csrf_build),
digestmod=hashlib.sha1
).hexdigest()
return safe_str_cmp(hmac_compare, hmac_csrf)
