pyicam 0.1.0
SAML 2.0 client authentication library
License: CC0-1.0
Keywords: saml saml2 sso icam noaa

PyICAM
======

.. figure:: https://img.shields.io/badge/license-CC0-green.png
   :alt: License: Creative Commons Zero v1.0 Universal

Python Identity, Credential, and Access Management.

Install
-------

::

    pip install pyicam

Windows Installation
~~~~~~~~~~~~~~~~~~~~

Installation may proceed more easily, by first downloading the
`python-xmlsec <https://github.com/mehcode/python-xmlsec#windows-wheel>`__
dependency wheel:

1). Download appropriate binary wheel from
`ci.appveyor.com <https://ci.appveyor.com/project/bgaifullin/python-xmlsec>`__
(see the ``Job [your-version]`` link, then ``Artifacts`` button on the
left).

2). Install wheel

::

    pip install <wheel filename>

3). Install

::

    pip install pyicam

Supported Python Versions
-------------------------

-  Python 3.3+

Overview
--------

PyICAM is a simple, SAML authentication library to help Python software
developers use the `NOAA Identity, Credential, Access and Federation
Management (ICAM) <https://noaaonline.noaa.gov/contact_us.html>`__ login
provider in a consistent fashion.

It consists of a minimal, easy to use interface around the open-source
`python3-saml <https://pypi.python.org/pypi/python3-saml>`__ toolkit
from Onelogin, Inc.

Online documentation is at https://github.com/nwfsc-data/PyICAM

Disclaimer
----------

This repository is a scientific product and is not official
communication of the National Oceanic and Atmospheric Administration, or
the United States Department of Commerce. All NOAA GitHub project code
is provided on an ‘as is’ basis and the user assumes responsibility for
its use. Any claims against the Department of Commerce or Department of
Commerce bureaus stemming from the use of this GitHub project will be
governed by all applicable Federal law. Any reference to specific
commercial products, processes, or services by service mark, trademark,
manufacturer, or otherwise, does not constitute or imply their
endorsement, recommendation or favoring by the Department of Commerce.
The Department of Commerce seal and logo, or the seal and logo of a DOC
bureau, shall not be used in any manner to imply endorsement of any
commercial product or activity by DOC or the United States Government.

Quick Start
-----------

Add SSO authentication to your existing Python webserver, with these
steps:

-  `Certificate & Secret key <#certificate-secret-key>`__
-  `Define your application
   attributes <#define-your-application-attributes>`__
-  `Obtain SSO Authority
   attributes <#obtain-sso-authority-attributes>`__
-  `Create settings file <#create-settings-file>`__
-  `Submit Metadata <#submit-metadata>`__
-  `Add your metadata URL <#add-your-metadata-url>`__
-  `Add your login URL <#add-your-login-url>`__
-  `Add your logout URL <#add-your-logout-url>`__ - TBD

Certificate & Secret key
~~~~~~~~~~~~~~~~~~~~~~~~

1). Your Python application will identify itself to others with a public
certificate, and private key used for signing.

Obtain a keypair that is acceptable by the SSO team (your organization
may already have a keypair which would be suitable to identify your
webserver).

If none is available, the following command may be used to generate a
new secret key & certificate request for signature:

::

    openssl req -new -newkey rsa:2048 -nodes -keyout secrets/server.key -out CERT_REQUEST.csr

-  Complete certificate details, as required by the Certificate
   Authority from whom you obtain a signed HTTPS certificate (contact
   your PKI team for more info on your CA's requirements).
-  Send your Certificate Authority the contents of: ``CERT_REQUEST.csr``
-  keep your ``secrets/server.key`` file secure. If anyone, at any time,
   can read this file - they can copy the key and impersonate your
   Python webserver.

Define your application attributes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

2). Make up some values, which will later be entered into a JSON
settings file. These can be any values you want for your application,
but should follow below format recommendations to minimize later
problems.

Define a unique name, id, description & three URLs for your webserver.
The URLs will be used to identify your webserver, and accept SSO and
Single-Log-Out (SLO) transmissions from the remote SSO authority:

-  serviceName: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
-  (Make a simple name for your application: "Amazing FRAM Service dev")
-  serviceId: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ (short, no
   spaces. E.g.: "AmazingFRAMServiceDev")
-  serviceDescription:
   \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
-  (A short description. E.g.: "Amazing FRAM service development
   instance")
-  custom URLs:

   -  entityIdURL:
      \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

      -  (E.g.:
         ``https://my.sample_domain/great_service/saml/metadata/``)
      -  (This will be used by ICAM SSO team and others to learn about
         your service, "saml/metadata/" is a very conventional URI
         ending for this)

   -  assertionConsumerServiceURL:
      \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
      (E.g.: ``https://my.sample_domain/great_service/saml/?acs``)
   -  singleLogoutServiceURL:
      \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
      (E.g.: ``https://my.sample_domain/great_service/saml/?sls``)

Obtain SSO Authority attributes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

3). Contact the operator of your SSO solution, and obtain their Identity
Provider metadata. Generally this will be provided via an XML document
named ``noaa-online-idp-metadata.xml`` or similar.

Gather details for the id, url & identifying certificate from the XML.
This info will be used in Step 4:

-  id: \_\_\_\_\_\_\_\_\_\_\_\_\_\_ (XML encodes this as "entityID"
   property of the "EntityDescriptor" element. It's typically short, no
   spaces. Often also at the end of the authority URLs)
-  certificateText:
   \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
   (will be long, base64 encoded text within a "ds:X509Certificate"
   element)
-  remote SSO authority URLs:

   -  singleSignOnServiceURL:
      \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

      -  (Use the sign-on Location value which has
         Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST")

   -  singleLogoutServiceURL:
      \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

      -  (Use logout Location value which has
         Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect")

Create settings file
~~~~~~~~~~~~~~~~~~~~

4). Create a file called ``settings.json`` and populate it with the
details from Step 2. & 3.:

::

    {
        "strict": true,

        "debug": true,

        "sp": {
            "entityId": "__Enter_step2_entityIdURL__",
            "assertionConsumerService": {
                "url": "__Enter_step2_assertionConsumerServiceURL__",
                "binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST"
            },
            "singleLogoutService": {
                "url": "__Enter_step2_singleLogoutServiceURL__",
                "binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect"
            },
            "attributeConsumingService": {
                    "serviceName": "__Enter_step2_name__",
                    "serviceDescription": "__Enter_step2_description__",
                    "requestedAttributes": [
                        {
                            "name": "__Enter_step2_id__",
                            "isRequired": false,
                            "nameFormat": "",
                            "friendlyName": "",
                            "attributeValue": []
                        }
                    ]
            },
            "NameIDFormat": "urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified",
            "x509cert": "",
            "privateKey": ""
        },

        "security": {
            "wantAssertionsSigned": true
        },

        "idp": {
            "entityId": "__Enter_step3_id__",
            "singleSignOnService": {
                "url": "__Enter_step3_singleSignOnServiceURL__",
                "binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect"
            },
            "singleLogoutService": {
                "url": "__Enter_step3_singleLogoutServiceURL__",
                "binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect"
            },
            "x509cert": "__Enter_step3_certificateText__"

        }
    }

Submit metadata
~~~~~~~~~~~~~~~

5). Generate metadata for your webserver, using the following code &
submit the resulting ``metadata`` text to your SSO authority.

.. code:: python

    from pyicam.saml.metadata import get_entity_descriptor
    settings = 'settings.json' #specify the path to your files
    cert = 'cert.pem' #save cert issued by your Certificate Authority in Step 1). in PEM format
    key = 'secrets/server.key'
    metadata, content_type = get_entity_descriptor(settings, cert, key)
    print(metadata)

-  Your SSO Identity Provider operator will let you know if submitted
   metadata is acceptable, or if any settings changes must be made.
-  SSO operator will provide you with a login URL for "IdP-Initiated
   SSO". Directing your users to this link allows them to log into your
   application via the SSO Identity server:
   \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Add your metadata URL
~~~~~~~~~~~~~~~~~~~~~

6). Add the custom entityIdURL from `Step: Define your application
attributes <#define-your-application-attributes>`__ to your webserver,
so it returns metadata as shown in the previous `Step: Submit
metadata <#submit-metadata>`__.

-  Note: the HTTP response returned by the URL must have the content
   type (``text/xml``) indicated by PyICAM.

Add your login URL
~~~~~~~~~~~~~~~~~~

7). Add the custom assertionConsumerServiceURL from `Step: Define your
application attributes <#define-your-application-attributes>`__ to your
webserver, to recieve login notifications via HTTP POST:

.. code:: python

    # step1) retrieve user details
    from pyicam.saml.sso import login
    host = "myserv.example.gov" # details for your webserver
    port = "443"
    path = "/myapp/saml" # url path for your assertionConsumerServiceURL
    settings = 'settings.json' #specify the path to your files
    cert = 'cert.pem'
    key = 'secrets/server.key'
    user = login(host, port, path, settings, cert, key, post_data=request.params) # also set parameter https=True if your webserver uses https on a port other than 443 
    # step2) log in the user, using the provided dict, to create a user session in whatever fashion your program uses
    # step3) your URL may now respond to the user, or redirect them, however you see fit
    if 'relay_state' in user:
        # If the SSO login URL specified a SAML2 "RelayState" parameter for
        # the final redirect destination, PyICAM will return that value as: 'relay_state'
        users_saml2_RelayState_redirect_value = user['relay_state']

Congratulations! Users may now log into your application via the SSO
link provided by your Identity authority in `Step: Submit
metadata <#submit-metadata>`__.

Add your logout URL
~~~~~~~~~~~~~~~~~~~

8). (Adding custom singleLogoutServiceURL - TBD)

Copyright (C) 2017-2018 ERT Inc.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^