authlib/jose/rfc7519/claims.py
import time
from authlib.jose.errors import (
MissingClaimError,
InvalidClaimError,
ExpiredTokenError,
InvalidTokenError,
)
class BaseClaims(dict):
"""Payload claims for JWT, which contains a validate interface.
:param payload: the payload dict of JWT
:param header: the header dict of JWT
:param options: validate options
:param params: other params
An example on ``options`` parameter, the format is inspired by
`OpenID Connect Claims`_::
{
"iss": {
"essential": True,
"values": ["https://example.com", "https://example.org"]
},
"sub": {
"essential": True
"value": "248289761001"
},
"jti": {
"validate": validate_jti
}
}
.. _`OpenID Connect Claims`:
http://openid.net/specs/openid-connect-core-1_0.html#IndividualClaimsRequests
"""
REGISTERED_CLAIMS = []
def __init__(self, payload, header, options=None, params=None):
super().__init__(payload)
self.header = header
self.options = options or {}
self.params = params or {}
def __getattr__(self, key):
try:
return object.__getattribute__(self, key)
except AttributeError as error:
if key in self.REGISTERED_CLAIMS:
return self.get(key)
raise error
def _validate_essential_claims(self):
for k in self.options:
if self.options[k].get('essential'):
if k not in self:
raise MissingClaimError(k)
elif not self.get(k):
raise InvalidClaimError(k)
def _validate_claim_value(self, claim_name):
option = self.options.get(claim_name)
if not option:
return
value = self.get(claim_name)
option_value = option.get('value')
if option_value and value != option_value:
raise InvalidClaimError(claim_name)
option_values = option.get('values')
if option_values and value not in option_values:
raise InvalidClaimError(claim_name)
validate = option.get('validate')
if validate and not validate(self, value):
raise InvalidClaimError(claim_name)
def get_registered_claims(self):
rv = {}
for k in self.REGISTERED_CLAIMS:
if k in self:
rv[k] = self[k]
return rv
class JWTClaims(BaseClaims):
REGISTERED_CLAIMS = ['iss', 'sub', 'aud', 'exp', 'nbf', 'iat', 'jti']
def validate(self, now=None, leeway=0):
"""Validate everything in claims payload."""
self._validate_essential_claims()
if now is None:
now = int(time.time())
self.validate_iss()
self.validate_sub()
self.validate_aud()
self.validate_exp(now, leeway)
self.validate_nbf(now, leeway)
self.validate_iat(now, leeway)
self.validate_jti()
# Validate custom claims
for key in self.options.keys():
if key not in self.REGISTERED_CLAIMS:
self._validate_claim_value(key)
def validate_iss(self):
"""The "iss" (issuer) claim identifies the principal that issued the
JWT. The processing of this claim is generally application specific.
The "iss" value is a case-sensitive string containing a StringOrURI
value. Use of this claim is OPTIONAL.
"""
self._validate_claim_value('iss')
def validate_sub(self):
"""The "sub" (subject) claim identifies the principal that is the
subject of the JWT. The claims in a JWT are normally statements
about the subject. The subject value MUST either be scoped to be
locally unique in the context of the issuer or be globally unique.
The processing of this claim is generally application specific. The
"sub" value is a case-sensitive string containing a StringOrURI
value. Use of this claim is OPTIONAL.
"""
self._validate_claim_value('sub')
def validate_aud(self):
"""The "aud" (audience) claim identifies the recipients that the JWT is
intended for. Each principal intended to process the JWT MUST
identify itself with a value in the audience claim. If the principal
processing the claim does not identify itself with a value in the
"aud" claim when this claim is present, then the JWT MUST be
rejected. In the general case, the "aud" value is an array of case-
sensitive strings, each containing a StringOrURI value. In the
special case when the JWT has one audience, the "aud" value MAY be a
single case-sensitive string containing a StringOrURI value. The
interpretation of audience values is generally application specific.
Use of this claim is OPTIONAL.
"""
aud_option = self.options.get('aud')
aud = self.get('aud')
if not aud_option or not aud:
return
aud_values = aud_option.get('values')
if not aud_values:
aud_value = aud_option.get('value')
if aud_value:
aud_values = [aud_value]
if not aud_values:
return
if isinstance(self['aud'], list):
aud_list = self['aud']
else:
aud_list = [self['aud']]
if not any([v in aud_list for v in aud_values]):
raise InvalidClaimError('aud')
def validate_exp(self, now, leeway):
"""The "exp" (expiration time) claim identifies the expiration time on
or after which the JWT MUST NOT be accepted for processing. The
processing of the "exp" claim requires that the current date/time
MUST be before the expiration date/time listed in the "exp" claim.
Implementers MAY provide for some small leeway, usually no more than
a few minutes, to account for clock skew. Its value MUST be a number
containing a NumericDate value. Use of this claim is OPTIONAL.
"""
if 'exp' in self:
exp = self['exp']
if not _validate_numeric_time(exp):
raise InvalidClaimError('exp')
if exp < (now - leeway):
raise ExpiredTokenError()
def validate_nbf(self, now, leeway):
"""The "nbf" (not before) claim identifies the time before which the JWT
MUST NOT be accepted for processing. The processing of the "nbf"
claim requires that the current date/time MUST be after or equal to
the not-before date/time listed in the "nbf" claim. Implementers MAY
provide for some small leeway, usually no more than a few minutes, to
account for clock skew. Its value MUST be a number containing a
NumericDate value. Use of this claim is OPTIONAL.
"""
if 'nbf' in self:
nbf = self['nbf']
if not _validate_numeric_time(nbf):
raise InvalidClaimError('nbf')
if nbf > (now + leeway):
raise InvalidTokenError()
def validate_iat(self, now, leeway):
"""The "iat" (issued at) claim identifies the time at which the JWT was
issued. This claim can be used to determine the age of the JWT.
Implementers MAY provide for some small leeway, usually no more
than a few minutes, to account for clock skew. Its value MUST be a
number containing a NumericDate value. Use of this claim is OPTIONAL.
"""
if 'iat' in self:
iat = self['iat']
if not _validate_numeric_time(iat):
raise InvalidClaimError('iat')
if iat > (now + leeway):
raise InvalidTokenError(
description='The token is not valid as it was issued in the future'
)
def validate_jti(self):
"""The "jti" (JWT ID) claim provides a unique identifier for the JWT.
The identifier value MUST be assigned in a manner that ensures that
there is a negligible probability that the same value will be
accidentally assigned to a different data object; if the application
uses multiple issuers, collisions MUST be prevented among values
produced by different issuers as well. The "jti" claim can be used
to prevent the JWT from being replayed. The "jti" value is a case-
sensitive string. Use of this claim is OPTIONAL.
"""
self._validate_claim_value('jti')
def _validate_numeric_time(s):
return isinstance(s, (int, float))