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Module hug.authentication

hug/authentication.py

Provides the basic built-in authentication helper functions

Copyright (C) 2016 Timothy Edmund Crosley

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

View Source

"""hug/authentication.py

Provides the basic built-in authentication helper functions

Copyright (C) 2016  Timothy Edmund Crosley

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated

documentation files (the "Software"), to deal in the Software without restriction, including without limitation

the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and

to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or

substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED

TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF

CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

OTHER DEALINGS IN THE SOFTWARE.

"""

from __future__ import absolute_import

import base64

import binascii

from falcon import HTTPUnauthorized

def authenticator(function, challenges=()):

    """Wraps authentication logic, verify_user through to the authentication function.

    The verify_user function passed in should accept an API key and return a user object to

    store in the request context if authentication succeeded.

    """

    challenges = challenges or ('{} realm="simple"'.format(function.__name__),)

    def wrapper(verify_user):

        def authenticate(request, response, **kwargs):

            result = function(request, response, verify_user, **kwargs)

            def authenticator_name():

                try:

                    return function.__doc__.splitlines()[0]

                except AttributeError:

                    return function.__name__

            if result is None:

                raise HTTPUnauthorized(

                    "Authentication Required",

                    "Please provide valid {0} credentials".format(authenticator_name()),

                    challenges=challenges,

                )

            if result is False:

                raise HTTPUnauthorized(

                    "Invalid Authentication",

                    "Provided {0} credentials were invalid".format(authenticator_name()),

                    challenges=challenges,

                )

            request.context["user"] = result

            return True

        authenticate.__doc__ = function.__doc__

        return authenticate

    return wrapper

@authenticator

def basic(request, response, verify_user, realm="simple", context=None, **kwargs):

    """Basic HTTP Authentication"""

    http_auth = request.auth

    response.set_header("WWW-Authenticate", "Basic")

    if http_auth is None:

        return

    if isinstance(http_auth, bytes):

        http_auth = http_auth.decode("utf8")

    try:

        auth_type, user_and_key = http_auth.split(" ", 1)

    except ValueError:

        raise HTTPUnauthorized(

            "Authentication Error",

            "Authentication header is improperly formed",

            challenges=('Basic realm="{}"'.format(realm),),

        )

    if auth_type.lower() == "basic":

        try:

            user_id, key = (

                base64.decodebytes(bytes(user_and_key.strip(), "utf8")).decode("utf8").split(":", 1)

            )

            try:

                user = verify_user(user_id, key)

            except TypeError:

                user = verify_user(user_id, key, context)

            if user:

                response.set_header("WWW-Authenticate", "")

                return user

        except (binascii.Error, ValueError):

            raise HTTPUnauthorized(

                "Authentication Error",

                "Unable to determine user and password with provided encoding",

                challenges=('Basic realm="{}"'.format(realm),),

            )

    return False

@authenticator

def api_key(request, response, verify_user, context=None, **kwargs):

    """API Key Header Authentication

    The verify_user function passed in to ths authenticator shall receive an

    API key as input, and return a user object to store in the request context

    if the request was successful.

    """

    api_key = request.get_header("X-Api-Key")

    if api_key:

        try:

            user = verify_user(api_key)

        except TypeError:

            user = verify_user(api_key, context)

        if user:

            return user

        else:

            return False

    else:

        return None

@authenticator

def token(request, response, verify_user, context=None, **kwargs):

    """Token verification

    Checks for the Authorization header and verifies using the verify_user function

    """

    token = request.get_header("Authorization")

    if token:

        try:

            verified_token = verify_user(token)

        except TypeError:

            verified_token = verify_user(token, context)

        if verified_token:

            return verified_token

        else:

            return False

    return None

def verify(user, password):

    """Returns a simple verification callback that simply verifies that the users and password match that provided"""

    def verify_user(user_name, user_password):

        if user_name == user and user_password == password:

            return user_name

        return False

    return verify_user

Functions

api_key

def api_key(
    verify_user
)

View Source

    def wrapper(verify_user):

        def authenticate(request, response, **kwargs):

            result = function(request, response, verify_user, **kwargs)

            def authenticator_name():

                try:

                    return function.__doc__.splitlines()[0]

                except AttributeError:

                    return function.__name__

            if result is None:

                raise HTTPUnauthorized(

                    "Authentication Required",

                    "Please provide valid {0} credentials".format(authenticator_name()),

                    challenges=challenges,

                )

            if result is False:

                raise HTTPUnauthorized(

                    "Invalid Authentication",

                    "Provided {0} credentials were invalid".format(authenticator_name()),

                    challenges=challenges,

                )

            request.context["user"] = result

            return True

        authenticate.__doc__ = function.__doc__

        return authenticate

authenticator

def authenticator(
    function,
    challenges=()
)

Wraps authentication logic, verify_user through to the authentication function.

The verify_user function passed in should accept an API key and return a user object to store in the request context if authentication succeeded.

View Source

def authenticator(function, challenges=()):

    """Wraps authentication logic, verify_user through to the authentication function.

    The verify_user function passed in should accept an API key and return a user object to

    store in the request context if authentication succeeded.

    """

    challenges = challenges or ('{} realm="simple"'.format(function.__name__),)

    def wrapper(verify_user):

        def authenticate(request, response, **kwargs):

            result = function(request, response, verify_user, **kwargs)

            def authenticator_name():

                try:

                    return function.__doc__.splitlines()[0]

                except AttributeError:

                    return function.__name__

            if result is None:

                raise HTTPUnauthorized(

                    "Authentication Required",

                    "Please provide valid {0} credentials".format(authenticator_name()),

                    challenges=challenges,

                )

            if result is False:

                raise HTTPUnauthorized(

                    "Invalid Authentication",

                    "Provided {0} credentials were invalid".format(authenticator_name()),

                    challenges=challenges,

                )

            request.context["user"] = result

            return True

        authenticate.__doc__ = function.__doc__

        return authenticate

    return wrapper

basic

def basic(
    verify_user
)

View Source

    def wrapper(verify_user):

        def authenticate(request, response, **kwargs):

            result = function(request, response, verify_user, **kwargs)

            def authenticator_name():

                try:

                    return function.__doc__.splitlines()[0]

                except AttributeError:

                    return function.__name__

            if result is None:

                raise HTTPUnauthorized(

                    "Authentication Required",

                    "Please provide valid {0} credentials".format(authenticator_name()),

                    challenges=challenges,

                )

            if result is False:

                raise HTTPUnauthorized(

                    "Invalid Authentication",

                    "Provided {0} credentials were invalid".format(authenticator_name()),

                    challenges=challenges,

                )

            request.context["user"] = result

            return True

        authenticate.__doc__ = function.__doc__

        return authenticate

token

def token(
    verify_user
)

View Source

    def wrapper(verify_user):

        def authenticate(request, response, **kwargs):

            result = function(request, response, verify_user, **kwargs)

            def authenticator_name():

                try:

                    return function.__doc__.splitlines()[0]

                except AttributeError:

                    return function.__name__

            if result is None:

                raise HTTPUnauthorized(

                    "Authentication Required",

                    "Please provide valid {0} credentials".format(authenticator_name()),

                    challenges=challenges,

                )

            if result is False:

                raise HTTPUnauthorized(

                    "Invalid Authentication",

                    "Provided {0} credentials were invalid".format(authenticator_name()),

                    challenges=challenges,

                )

            request.context["user"] = result

            return True

        authenticate.__doc__ = function.__doc__

        return authenticate

verify

def verify(
    user,
    password
)

Returns a simple verification callback that simply verifies that the users and password match that provided

View Source

def verify(user, password):

    """Returns a simple verification callback that simply verifies that the users and password match that provided"""

    def verify_user(user_name, user_password):

        if user_name == user and user_password == password:

            return user_name

        return False

    return verify_user