Satosa-Saml2Spid

A SAML2/OIDC configuration for SATOSA that aims to setup a SAML-to-SAML Proxy and OIDC-to-SAML compatible with the Italian Digital Identity Systems.

Glossary

Frontend, interface of the proxy that is configured as a SAML2 Identity Provider
Backend, interface of the proxy that is configured as a SAML2 Service Provider
TargetRouting, a SATOSA microservice for selecting the output backend to reach the endpoint (IdP) selected by the user
Discovery Service, interface that allows users to select the authentication endpoint

General features

Backends:

SPID SP
CIE SP
eIDAS FICEP SP
SAML2 SP

Frontends:

SAML2 IDP
OIDC OP (see satosa-oidcop)

This project is tested in Continuous Integration with spid-sp-test and passes all the tests regarding Metadata, Authn Requests and Responses.

Goal

Satosa-Saml2 Spid is an intermediary between many SAML2/OIDC Service Providers and many SAML2 Identity Providers. It allows traditional Saml2 Service Providers to communicate with Spid and CIE Identity Providers adapting Metadata and AuthnRequest operations.

Figure1 : Traditional SAML2 Service Providers (SPs) proxied through the SATOSA SPID Backend gets compliances on AuthnRequest and Metadata operations.

This solution configures multiple proxy frontends and backends to get communicating systems that, due to protocol or specific limitations, traditionally could not interact each other.

Demo components

The example project comes with the following demo pages, served with the help of an additional webserver dedicated for static contents:

Discovery Service page

Generic error page

Saml2 Signature Error page

AgID SPID test #104

These demo pages are static files, available in example/static. To get redirection to these pages, or redirection to third-party services, it is required to configure the parameters below:

file: example/proxy_conf.yml, example value: UNKNOW_ERROR_REDIRECT_PAGE: "https://localhost:9999/error_page.html"
file: example/plugins/{backends,frontends}/$filename, example value: disco_srv: "https://localhost:9999/static/disco.html"

Docker image

the official Satosa-Saml2SPID docker image is available at italia/satosa-saml2spid

To install the official docker image, simply type: sudo docker pull ghcr.io/italia/satosa-saml2spid:latest

Docker compose

Satosa-Saml2SPID image is built with production ready logic, anyway some configurations are required! The docker compose may use the enviroment variables of satosa-saml2spid.

See compose-Satosa-Saml2Spid for details.

NGINX setup

A valid ssl certificate is needed, to add your certificate you have to override the /etc/nginx/certs directory with your docker volume, containing your certificates.

Setup

Dependencies Ubuntu

sudo apt install -y libffi-dev libssl-dev python3-pip xmlsec1 procps libpcre3 libpcre3-dev

Dependencies Centos/RHEL

sudo yum install -y libffi-devel openssl-devel python3-pip xmlsec1 procps pcre pcre-devel
sudo yum groupinstall "Development Tools"
sudo yum install -y python3-wheel python3-devel

Prepare environment

pip install --upgrade pip
pip install virtualenv

mkdir satosa_proxy && cd satosa_proxy
virtualenv -ppython3 satosa.env
source satosa.env/bin/activate

git clone https://github.com/italia/Satosa-Saml2Spid.git repository
cd repository
pip install -r requirements.txt

Configure the Proxy

Create certificates for SPID see psmiraglia.
Copy repository/example/* contents (cp -R repository/example/* .) and edit the files below
- proxy_conf.yaml
- plugins/backends/spidsaml2_backend.yaml
- plugins/backends/saml2_backend.yaml
- plugins/frontend/saml2_frontend.yaml
- plugins/frontend/oidc_op_frontend.yaml (optional to enable OIDC Provider)

Remember to:

edit and customize all the values like "CHANGE_ME!" in the configuration files, in proxy_conf.yaml and in the configurations of the plugins.
set the $HOSTNAME environment with the production DNS name
set all key and salt with your secret key ($SATOSA_ENCRYPTION_KEY, $SATOSA_SALT)
set a new mongodb password ($MONGODB_USERNAME, $MONGODB_PASSWORD)
set a new certificate for SAML / SPID ($SATOSA_PUBLIC_KEYS, $SATOSA_PRIVATE_KEYS)
add valid data for metadata, read Configurations by environments

OIDC

This project uses SATOSA_oidcop as OAuth2/OIDC frontend module. Comment/uncomment the following statement in the proxy_configuration to enable it.

https://github.com/italia/Satosa-Saml2Spid/blob/oidcop/example/proxy_conf.yaml#L32

Configuration by environment variables

You can override the configuration of the proxy by settings one or more of the following environment variables:

Environment var	description	default
$SATOSA_BASE	base url of satosa server	"https://$HOSTNAME"
$SATOSA_ENCRYPTION_KEY	encription key for state	"CHANGE_ME!"
$SATOSA_SALT	encription salt	"CHANGE_ME!"
$SATOSA_DISCO_SRV	Descovery page URL for all backends	"https://$HOSTNAME/static/disco.html"
$SATOSA_PRIVATE_KEYS	private key for SAML2 / SPID backends
$SATOSA_PUBLIC_KEYS	public key for SAML2 / SPID backends
$MONGODB_USERNAME	MongoDB username for oidc_op frontend, default from .env file in compose-Satosa-Saml2Spid
$MONGODB_PASSWORD	MongoDB password for oidc_op frontend, default from .env file in compose-Satosa-Saml2Spid
$SATOSA_UNKNOW_ERROR_REDIRECT_PAGE	redirect page for unknow erros	"https://$HOSTNAME/static/error_page.html"
$SATOSA_ORGANIZATION_DISPLAY_NAME_EN	Metadata English organization display name
$SATOSA_ORGANIZATION_NAME_EN	Metadata English full organization name
$SATOSA_ORGANIZATION_URL_EN	Metadata English organization url
$SATOSA_ORGANIZATION_DISPLAY_NAME_IT	Metadata Italian Organization display name
$SATOSA_ORGANIZATION_NAME_IT	Metadata Italian full organization
$SATOSA_ORGANIZATION_URL_IT	Metadata Italian organization url
$SATOSA_CONTACT_PERSON_GIVEN_NAME	Metadata Contact person name
$SATOSA_CONTACT_PERSON_EMAIL_ADDRESS	Metadata Contact person email
$SATOSA_CONTACT_PERSON_TELEPHONE_NUMBER	Metadata Contact person telephone number for SPID / CIE Backend
$SATOSA_CONTACT_PERSON_FISCALCODE	Metadata Contact person fiscal code for SPID / CIE Backend
$SATOSA_UI_DISPLAY_NAME_EN	Metadata English ui display name
$SATOSA_UI_DISPLAY_NAME_IT	Metadata Italian ui display name
$SATOSA_UI_DESCRIPTION_EN	Metadata English ui description
$SATOSA_UI_DESCRIPTION_IT	Metadata Italian ui description
$SATOSA_UI_INFORMATION_URL_EN	Metadata English ui information URL
$SATOSA_UI_INFORMATION_URL_IT	Metadata Italian ui information URL
$SATOSA_UI_PRIVACY_URL_EN	Metadata English ui privacy URL
$SATOSA_UI_PRIVACY_URL_IT	Metadata Italian ui privacy URL
$SATOSA_UI_LOGO_URL	Metadata Logo url for
$SATOSA_UI_LOGO_WIDTH	Metadata Logo width
$SATOSA_UI_LOGO_HEIGHT	Metadata logo height
$SATOSA_SAML2_REQUESTED_ATTRIBUTES	SAML2 required attributes	name, surname
$SATOSA_SPID_REQUESTED_ATTRIBUTES	SPID required attributes	spidCode, name, familyName, fiscalNumber, email

Saml2 Metadata

If you want to handle metadata file manually create the metadata/idp and metadata/sp directories, then copy the required metadata:

mkdir -p metadata/idp metadata/sp
wget https://localhost:8080/metadata.xml -O metadata/idp/spid-saml-check.xml
wget https://registry.spid.gov.it/metadata/idp/spid-entities-idps.xml -O metadata/idp/spid-entities-idps.xml

Copy your SP metadata to your Proxy

wget https://sp.fqdn.org/saml2/metadata -O metadata/sp/my-sp.xml

Otherwise the best method would be enabling a MDQ server in each frontend and backend configuration file. See example/plugins/{backends,frontends}/$filename as example.

Start the Proxy

Warning: these examples must be intended only for test purpose, for a demo run. Please remember that the following examples wouldn't be intended for a real production environment.

If you need some example for a production environment please take a look at example/uwsgi_setup/ directory or use the docker-compose.

export SATOSA_APP=$VIRTUAL_ENV/lib/$(python -c 'import sys; print(f"python{sys.version_info.major}.{sys.version_info.minor}")')/site-packages/satosa

# only https with satosa, because its Cookie only if "secure" would be sent
uwsgi --wsgi-file $SATOSA_APP/wsgi.py  --https 0.0.0.0:10000,./pki/cert.pem,./pki/privkey.pem --callable app -b 32768

# additional static serve for the demo Discovery Service with Spid button
uwsgi --https 0.0.0.0:9999,./pki/cert.pem,./pki/privkey.pem --check-static-docroot --check-static ./static/ --static-index disco.html

Get SPID backend metadata

The proxy backend exposes its SPID metadata at the following url (customizable):

https://localhost:10000/spidSaml2/metadata

Get Proxy Fronted Metadata for your SP

The Proxy metadata must be configured in your SP. Your SP is an entity that's external from this Proxy, eg: shibboleth sp, djangosaml2, another ...

wget https://localhost:10000/Saml2IDP/metadata -O path/to/your/sp/metadata/satosa-spid.xml --no-check-certificate

Then start an authentication from your SP.

Figure 2: The result using spid-saml-check.

Hints

If you're doing tests and you don't want to pass by Discovery page each time you can use idphinting but only if your SP support it! Here an example using djangosaml2 as SP:

http://localhost:8000/saml2/login/?idp=https://localhost:10000/Saml2IDP/metadata&next=/saml2/echo_attributes&idphint=https%253A%252F%252Flocalhost%253A8080

IF you're going to test Satosa-Saml2Spid with spid-sp-test, take a look to its CI, here,

Trouble shooting

That's the stdout log of a working instance of SATOSA in uwsgi

*** Starting uWSGI 2.0.19.1 (64bit) on [Tue Mar 30 17:08:49 2021] ***
compiled with version: 9.3.0 on 11 September 2020 23:11:42
os: Linux-5.4.0-70-generic #78-Ubuntu SMP Fri Mar 19 13:29:52 UTC 2021
nodename: wert-desktop
machine: x86_64
clock source: unix
pcre jit disabled
detected number of CPU cores: 8
current working directory: /path/to/IdentityPython/satosa_proxy
detected binary path: /path/to/IdentityPython/satosa_proxy/satosa.env/bin/uwsgi
your processes number limit is 62315
your memory page size is 4096 bytes
detected max file descriptor number: 1024
lock engine: pthread robust mutexes
uWSGI http bound on 0.0.0.0:10000 fd 4
spawned uWSGI http 1 (pid: 28676)
uwsgi socket 0 bound to TCP address 127.0.0.1:39553 (port auto-assigned) fd 3
Python version: 3.8.5 (default, Jan 27 2021, 15:41:15)  [GCC 9.3.0]
Python main interpreter initialized at 0x55f744576790
your server socket listen backlog is limited to 100 connections
your mercy for graceful operations on workers is 60 seconds
mapped 72920 bytes (71 KB) for 1 cores
*** Operational MODE: single process ***
[2021-03-30 17:08:50] [INFO ]: Running SATOSA version 7.0.1 [satosa.proxy_server.make_app:165]
[2021-03-30 17:08:50] [INFO ]: Loading backend modules... [satosa.base.__init__:42]
[2021-03-30 17:08:51] [INFO ]: Setup backends: ['Saml2', 'spidSaml2'] [satosa.plugin_loader.load_backends:49]
[2021-03-30 17:08:51] [INFO ]: Loading frontend modules... [satosa.base.__init__:45]
[2021-03-30 17:08:51] [INFO ]: Setup frontends: ['Saml2IDP'] [satosa.plugin_loader.load_frontends:70]
[2021-03-30 17:08:51] [INFO ]: Loading micro services... [satosa.base.__init__:51]
[2021-03-30 17:08:51] [INFO ]: Loaded request micro services: ['DecideBackendByTarget'] [satosa.plugin_loader.load_request_microservices:260]
[2021-03-30 17:08:51] [INFO ]: Loaded response micro services:[] [satosa.plugin_loader.load_response_microservices:281]
WSGI app 0 (mountpoint='') ready in 2 seconds on interpreter 0x55f744576790 pid: 28675 (default app)
*** uWSGI is running in multiple interpreter mode ***
spawned uWSGI worker 1 (and the only) (pid: 28675, cores: 8)

Additional technical informations for Developers

SPID technical Requirements

The SaToSa SPID backend contained in this project adopt specialized forks of pySAML2 and SATOSA, that implements the following patches, read this for any further explaination about how to patch by hands.

All the patches and features are currently merged and available with the following releases:

Pending contributions to idpy

These are mandatory only for getting Spid SAML2 working, these are not needed for any other traditional SAML2 deployment:

Warnings

Here something that you should know before start.

You must enable more than a single IdP (multiple metadata or single metadata with multiple entities) to get Discovery Service working.
Proxy doesn't handle SAML2 SLO, so the spidSaml2 backend is configured with Authnforce -> True. For any further information see Single Logout in Satosa.
SATOSA Saml2 backend configuration has a policy section that will let us to define specialized behaviours and configuration for each SP (each by entityid). In this example I defined a single "default" behaviour with attributes name_format to urn:oasis:names:tc:SAML:2.0:attrname-format:uri, due to my needs to handle many service providers for which it could be painfull do a static definition each time. An additional "hack" have been made in example/attributes-maps/satosa_spid_uri_hybrid.py, where I adopted a hybrid mapping that works for both URI and BASIC formats. Feel free to customized or decouple these format in different files and per SP.

External references