api_jwt.py 7.2 KB

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  1. import json
  2. import warnings
  3. from calendar import timegm
  4. from collections import Iterable, Mapping
  5. from datetime import datetime, timedelta
  6. from .api_jws import PyJWS
  7. from .algorithms import Algorithm, get_default_algorithms # NOQA
  8. from .compat import string_types
  9. from .exceptions import (
  10. DecodeError, ExpiredSignatureError, ImmatureSignatureError,
  11. InvalidAudienceError, InvalidIssuedAtError,
  12. InvalidIssuerError, MissingRequiredClaimError
  13. )
  14. from .utils import merge_dict
  15. class PyJWT(PyJWS):
  16. header_type = 'JWT'
  17. @staticmethod
  18. def _get_default_options():
  19. return {
  20. 'verify_signature': True,
  21. 'verify_exp': True,
  22. 'verify_nbf': True,
  23. 'verify_iat': True,
  24. 'verify_aud': True,
  25. 'verify_iss': True,
  26. 'require_exp': False,
  27. 'require_iat': False,
  28. 'require_nbf': False
  29. }
  30. def encode(self, payload, key, algorithm='HS256', headers=None,
  31. json_encoder=None):
  32. # Check that we get a mapping
  33. if not isinstance(payload, Mapping):
  34. raise TypeError('Expecting a mapping object, as JWT only supports '
  35. 'JSON objects as payloads.')
  36. # Payload
  37. for time_claim in ['exp', 'iat', 'nbf']:
  38. # Convert datetime to a intDate value in known time-format claims
  39. if isinstance(payload.get(time_claim), datetime):
  40. payload[time_claim] = timegm(payload[time_claim].utctimetuple())
  41. json_payload = json.dumps(
  42. payload,
  43. separators=(',', ':'),
  44. cls=json_encoder
  45. ).encode('utf-8')
  46. return super(PyJWT, self).encode(
  47. json_payload, key, algorithm, headers, json_encoder
  48. )
  49. def decode(self, jwt, key='', verify=True, algorithms=None, options=None,
  50. **kwargs):
  51. if verify and not algorithms:
  52. warnings.warn(
  53. 'It is strongly recommended that you pass in a ' +
  54. 'value for the "algorithms" argument when calling decode(). ' +
  55. 'This argument will be mandatory in a future version.',
  56. DeprecationWarning
  57. )
  58. payload, signing_input, header, signature = self._load(jwt)
  59. if options is None:
  60. options = {'verify_signature': verify}
  61. else:
  62. options.setdefault('verify_signature', verify)
  63. decoded = super(PyJWT, self).decode(
  64. jwt, key=key, algorithms=algorithms, options=options, **kwargs
  65. )
  66. try:
  67. payload = json.loads(decoded.decode('utf-8'))
  68. except ValueError as e:
  69. raise DecodeError('Invalid payload string: %s' % e)
  70. if not isinstance(payload, Mapping):
  71. raise DecodeError('Invalid payload string: must be a json object')
  72. if verify:
  73. merged_options = merge_dict(self.options, options)
  74. self._validate_claims(payload, merged_options, **kwargs)
  75. return payload
  76. def _validate_claims(self, payload, options, audience=None, issuer=None,
  77. leeway=0, **kwargs):
  78. if 'verify_expiration' in kwargs:
  79. options['verify_exp'] = kwargs.get('verify_expiration', True)
  80. warnings.warn('The verify_expiration parameter is deprecated. '
  81. 'Please use verify_exp in options instead.',
  82. DeprecationWarning)
  83. if isinstance(leeway, timedelta):
  84. leeway = leeway.total_seconds()
  85. if not isinstance(audience, (string_types, type(None), Iterable)):
  86. raise TypeError('audience must be a string, iterable, or None')
  87. self._validate_required_claims(payload, options)
  88. now = timegm(datetime.utcnow().utctimetuple())
  89. if 'iat' in payload and options.get('verify_iat'):
  90. self._validate_iat(payload, now, leeway)
  91. if 'nbf' in payload and options.get('verify_nbf'):
  92. self._validate_nbf(payload, now, leeway)
  93. if 'exp' in payload and options.get('verify_exp'):
  94. self._validate_exp(payload, now, leeway)
  95. if options.get('verify_iss'):
  96. self._validate_iss(payload, issuer)
  97. if options.get('verify_aud'):
  98. self._validate_aud(payload, audience)
  99. def _validate_required_claims(self, payload, options):
  100. if options.get('require_exp') and payload.get('exp') is None:
  101. raise MissingRequiredClaimError('exp')
  102. if options.get('require_iat') and payload.get('iat') is None:
  103. raise MissingRequiredClaimError('iat')
  104. if options.get('require_nbf') and payload.get('nbf') is None:
  105. raise MissingRequiredClaimError('nbf')
  106. def _validate_iat(self, payload, now, leeway):
  107. try:
  108. int(payload['iat'])
  109. except ValueError:
  110. raise InvalidIssuedAtError('Issued At claim (iat) must be an integer.')
  111. def _validate_nbf(self, payload, now, leeway):
  112. try:
  113. nbf = int(payload['nbf'])
  114. except ValueError:
  115. raise DecodeError('Not Before claim (nbf) must be an integer.')
  116. if nbf > (now + leeway):
  117. raise ImmatureSignatureError('The token is not yet valid (nbf)')
  118. def _validate_exp(self, payload, now, leeway):
  119. try:
  120. exp = int(payload['exp'])
  121. except ValueError:
  122. raise DecodeError('Expiration Time claim (exp) must be an'
  123. ' integer.')
  124. if exp < (now - leeway):
  125. raise ExpiredSignatureError('Signature has expired')
  126. def _validate_aud(self, payload, audience):
  127. if audience is None and 'aud' not in payload:
  128. return
  129. if audience is not None and 'aud' not in payload:
  130. # Application specified an audience, but it could not be
  131. # verified since the token does not contain a claim.
  132. raise MissingRequiredClaimError('aud')
  133. if audience is None and 'aud' in payload:
  134. # Application did not specify an audience, but
  135. # the token has the 'aud' claim
  136. raise InvalidAudienceError('Invalid audience')
  137. audience_claims = payload['aud']
  138. if isinstance(audience_claims, string_types):
  139. audience_claims = [audience_claims]
  140. if not isinstance(audience_claims, list):
  141. raise InvalidAudienceError('Invalid claim format in token')
  142. if any(not isinstance(c, string_types) for c in audience_claims):
  143. raise InvalidAudienceError('Invalid claim format in token')
  144. if isinstance(audience, string_types):
  145. audience = [audience]
  146. if not any(aud in audience_claims for aud in audience):
  147. raise InvalidAudienceError('Invalid audience')
  148. def _validate_iss(self, payload, issuer):
  149. if issuer is None:
  150. return
  151. if 'iss' not in payload:
  152. raise MissingRequiredClaimError('iss')
  153. if payload['iss'] != issuer:
  154. raise InvalidIssuerError('Invalid issuer')
  155. _jwt_global_obj = PyJWT()
  156. encode = _jwt_global_obj.encode
  157. decode = _jwt_global_obj.decode
  158. register_algorithm = _jwt_global_obj.register_algorithm
  159. unregister_algorithm = _jwt_global_obj.unregister_algorithm
  160. get_unverified_header = _jwt_global_obj.get_unverified_header