# Path: src/wtforms/validators.py
# class ValidationError(ValueError):
#     """
#     Raised when a validator fails to validate its input.
#     """
# 
#     def __init__(self, message="", *args, **kwargs):
#         ValueError.__init__(self, message, *args, **kwargs)
# 
# Path: src/wtforms/csrf/core.py
# class CSRF:
#     field_class = CSRFTokenField
# 
#     def setup_form(self, form):
#         """
#         Receive the form we're attached to and set up fields.
# 
#         The default implementation creates a single field of
#         type :attr:`field_class` with name taken from the
#         ``csrf_field_name`` of the class meta.
# 
#         :param form:
#             The form instance we're attaching to.
#         :return:
#             A sequence of `(field_name, unbound_field)` 2-tuples which
#             are unbound fields to be added to the form.
#         """
#         meta = form.meta
#         field_name = meta.csrf_field_name
#         unbound_field = self.field_class(label="CSRF Token", csrf_impl=self)
#         return [(field_name, unbound_field)]
# 
#     def generate_csrf_token(self, csrf_token_field):
#         """
#         Implementations must override this to provide a method with which one
#         can get a CSRF token for this form.
# 
#         A CSRF token is usually a string that is generated deterministically
#         based on some sort of user data, though it can be anything which you
#         can validate on a subsequent request.
# 
#         :param csrf_token_field:
#             The field which is being used for CSRF.
#         :return:
#             A generated CSRF string.
#         """
#         raise NotImplementedError()
# 
#     def validate_csrf_token(self, form, field):
#         """
#         Override this method to provide custom CSRF validation logic.
# 
#         The default CSRF validation logic simply checks if the recently
#         generated token equals the one we received as formdata.
# 
#         :param form: The form which has this CSRF token.
#         :param field: The CSRF token field.
#         """
#         if field.current_token != field.data:
#             raise ValidationError(field.gettext("Invalid CSRF Token."))


import hmac
import os
from datetime import datetime
from datetime import timedelta
from hashlib import sha1
from ..validators import ValidationError
from .core import CSRF
"""
A provided CSRF implementation which puts CSRF data in a session.

This can be used fairly comfortably with many `request.session` type
objects, including the Werkzeug/Flask session store, Django sessions, and
potentially other similar objects which use a dict-like API for storing
session keys.

The basic concept is a randomly generated value is stored in the user's
session, and an hmac-sha1 of it (along with an optional expiration time,
for extra security) is used as the value of the csrf_token. If this token
validates with the hmac of the random value + expiration time, and the
expiration time is not passed, the CSRF validation will pass.
"""


__all__ = ("SessionCSRF",)



# Path: src/wtforms/validators.py
# class ValidationError(ValueError):
#     """
#     Raised when a validator fails to validate its input.
#     """
# 
#     def __init__(self, message="", *args, **kwargs):
#         ValueError.__init__(self, message, *args, **kwargs)
# 
# Path: src/wtforms/csrf/core.py
# class CSRF:
#     field_class = CSRFTokenField
# 
#     def setup_form(self, form):
#         """
#         Receive the form we're attached to and set up fields.
# 
#         The default implementation creates a single field of
#         type :attr:`field_class` with name taken from the
#         ``csrf_field_name`` of the class meta.
# 
#         :param form:
#             The form instance we're attaching to.
#         :return:
#             A sequence of `(field_name, unbound_field)` 2-tuples which
#             are unbound fields to be added to the form.
#         """
#         meta = form.meta
#         field_name = meta.csrf_field_name
#         unbound_field = self.field_class(label="CSRF Token", csrf_impl=self)
#         return [(field_name, unbound_field)]
# 
#     def generate_csrf_token(self, csrf_token_field):
#         """
#         Implementations must override this to provide a method with which one
#         can get a CSRF token for this form.
# 
#         A CSRF token is usually a string that is generated deterministically
#         based on some sort of user data, though it can be anything which you
#         can validate on a subsequent request.
# 
#         :param csrf_token_field:
#             The field which is being used for CSRF.
#         :return:
#             A generated CSRF string.
#         """
#         raise NotImplementedError()
# 
#     def validate_csrf_token(self, form, field):
#         """
#         Override this method to provide custom CSRF validation logic.
# 
#         The default CSRF validation logic simply checks if the recently
#         generated token equals the one we received as formdata.
# 
#         :param form: The form which has this CSRF token.
#         :param field: The CSRF token field.
#         """
#         if field.current_token != field.data:
#             raise ValidationError(field.gettext("Invalid CSRF Token."))


# Path: src/wtforms/csrf/session.py
import hmac
import os
from datetime import datetime
from datetime import timedelta
from hashlib import sha1
from ..validators import ValidationError
from .core import CSRF

"""
A provided CSRF implementation which puts CSRF data in a session.

This can be used fairly comfortably with many `request.session` type
objects, including the Werkzeug/Flask session store, Django sessions, and
potentially other similar objects which use a dict-like API for storing
session keys.

The basic concept is a randomly generated value is stored in the user's
session, and an hmac-sha1 of it (along with an optional expiration time,
for extra security) is used as the value of the csrf_token. If this token
validates with the hmac of the random value + expiration time, and the
expiration time is not passed, the CSRF validation will pass.
"""


__all__ = ("SessionCSRF",)



class SessionCSRF(CSRF):