def _unpack_header(self, headers):
"""
Unpacks a jwt token from a request header
"""
jwt_header = headers.get(self.header_name)
MissingTokenHeader.require_condition(
jwt_header is not None,
"JWT token not found in headers under '{}'",
self.header_name,
)
match = re.match(self.header_type + r'\s*([\w\.-]+)', jwt_header)
InvalidTokenHeader.require_condition(
match is not None,
"JWT header structure is invalid",
)
token = match.group(1)
return token
def refresh_jwt_token(self, token, override_access_lifespan=None):
"""
Creates a new token for a user if and only if the old token's access
permission is expired but its refresh permission is not yet expired.
The new token's refresh expiration moment is the same as the old
token's, but the new token's access expiration is refreshed
:param: token: The existing jwt token that needs to
be replaced with a new, refreshed
token
:param: override_access_lifespan: Override's the instance's access
lifespan to set a custom duration
after which the new token's
accessability will expire. May not
exceed the refresh lifespan
"""
moment = pendulum.now('UTC')
# Note: we disable exp verification because we do custom checks here
with InvalidTokenHeader.handle_errors('failed to decode JWT token'):
data = jwt.decode(
token,
self.encode_key,
algorithms=self.allowed_algorithms,
options={'verify_exp': False},
)
self._validate_jwt_data(data, access_type=AccessType.refresh)
user = self.user_class.identify(data['id'])
self._check_user(user)
if override_access_lifespan is None:
access_lifespan = self.access_lifespan
else:
access_lifespan = override_access_lifespan
refresh_expiration = data['rf_exp']
access_expiration = min(
(moment + access_lifespan).int_timestamp,
refresh_expiration,
)
custom_claims = {
k: v
for (k, v) in data.items() if k not in RESERVED_CLAIMS
}
payload_parts = dict(iat=moment.int_timestamp,
exp=access_expiration,
rf_exp=refresh_expiration,
jti=data['jti'],
id=data['id'],
rls=','.join(user.rolenames),
**custom_claims)
return jwt.encode(
payload_parts,
self.encode_key,
self.encode_algorithm,
).decode('utf-8')
def extract_jwt_token(self, token):
"""
Extracts a data dictionary from a jwt token
"""
# Note: we disable exp verification because we will do it ourselves
with InvalidTokenHeader.handle_errors('failed to decode JWT token'):
data = jwt.decode(
token,
self.encode_key,
algorithms=self.allowed_algorithms,
options={'verify_exp': False},
)
self._validate_jwt_data(data, access_type=AccessType.access)
return data