CURRENT VERSION: v0.35

spid-php-lib

PHP package for SPID authentication.

This PHP package is aimed at implementing SPID Service Providers. SPID is the Italian digital identity system, which enables citizens to access all public services with a single set of credentials. This package provides a layer of abstraction over the SAML protocol by exposing just the subset required in order to implement SPID authentication in a web application.

Alternatives for PHP:

• spid-php based on SimpleSAMLphp
• spid-php2 based on php-saml

Framework specific libraries and examples based on spid-php-lib:

• https://github.com/italia/spid-symfony-bundle
• https://github.com/simevo/spid-symfony3-example
• https://github.com/simevo/spid-wordpress

Alternatives for other languages:

• spid-perl
• spid-ruby

Table of Contents

• spid-php-lib
• Table of Contents
  • Repository layout
  • Getting Started
    • Prerequisites
    • Configuring and Installing
    • Usage
      • Performing login
      • Performing logout
      • Complete API
    • Example
      • Demo application
  • Features
    • More features
  • Troubleshooting
  • Testing
    • Unit tests
    • Linting
  • Contributing
  • See also
  • Authors
  • License

Repository layout

• bin/ auxiliary scripts
• example/ contains a demo application
• src/ contains the library implementation
• test/ contains the unit tests

Getting Started

Tested on: amd64 Debian 9.5 (stretch, current stable) with PHP 7.0.

Supports PHP 7.0, 7.1 and 7.2.

Prerequisites

sudo apt install composer make openssl php-curl php-zip php-xml

Configuring and Installing

NOTE: during testing, please use the test Identity Provider spid-testenv2.

1. Install with composer

   composer require italia/spid-php-lib

2. (OPTIONAL) Manually generate key and certificate files for your Service Provider (SP).

   Example: openssl req -x509 -nodes -sha256 -days 365 -newkey rsa:2048 -subj "/C=IT/ST=Italy/L=Milan/O=myservice/CN=localhost" -keyout sp.key -out sp.crt

   This step can be skipped: the library takes care of this step automatically if you declare the optional sp_key_cert_values key in the settings array. Check the example in the Usage section for further details.

3. Download the Identity Provider (IdP) metadata files and place them in a directory in your project, for example idp_metadata. A convenience tool is provided to download those of the production IdPs: vendor/italia/spid-php-lib/bin/download_idp_metadata.php, example usage:

   mkdir idp_metadata
   php vendor/italia/spid-php-lib/bin/download_idp_metadata.php ./idp_metadata

   TEST ENVIRONMENT: If you are using spid-testenv2, manually download the IdP metadata and place it in your idp_metadata folder

4. Make your SP known to IdPs: for production follow the guidelines at https://www.spid.gov.it/come-diventare-fornitore-di-servizi-pubblici-e-privati-con-spid

   TEST ENVIRONMENT: simply download your Service Provider (SP) metadata and place it in the appropriate folder of the test environment. The test environment must be restarted after every change to the SP metadata.

Usage

All classes provided by this package reside in the Italia\Spid namespace. More detailed documentation is available in the SAMLInterface.php file.

Load them using the composer-generated autoloader:

require_once(__DIR__ . "/vendor/autoload.php");

The main class is Italia\Spid\Sp (service provider).

Generate a settings array following this guideline

$settings = array(
    'sp_entityid' => SP_BASE_URL, // preferred: https protocol, no trailing slash, example: https://sp.example.com/
    'sp_key_file' => '/path/to/sp.key',
    'sp_cert_file' => '/path/to/sp.crt',
    'sp_comparison' => 'exact', // one of: "exact", "minimum", "better" or "maximum"
    'sp_assertionconsumerservice' => [
        // order is important ! the 0-base index in this array will be used as ID in the calls
        SP_BASE_URL . '/acs',
        ...
    ],
    'sp_singlelogoutservice' => [
        // order is important ! the 0-base index in this array will be used as ID in the calls
        [SP_BASE_URL . '/slo', 'POST'],
        [SP_BASE_URL . '/slo', 'REDIRECT']
        ...
    ],
    'sp_org_name' => 'your organization full name',
    'sp_org_display_name' => 'your organization display name',
    'sp_key_cert_values' => [ // Optional: remove this if you want to generate .key & .crt files manually
        'countryName' => 'Your Country',
        'stateOrProvinceName' => 'Your Province or State',
        'localityName' => 'Locality',
        'commonName' => 'Name',
        'emailAddress' => 'your@email.com',
    ]
    'idp_metadata_folder' => '/path/to/idp_metadata/',
    'sp_attributeconsumingservice' => [
        // order is important ! the 0-base index in this array will be used as ID in the calls
        ["fiscalNumber"],
        ["name", "familyName", "fiscalNumber", "email", "spidCode"],
        ...
    ],
    // Time in seconds of skew that is acceptable between client and server when checking OnBefore and NotOnOrAfter
    // assertion condition validity timestamps, and IssueInstant response / assertion timestamps. Optional.
    // Default is 0. Acceptable range: 0-300 (inclusive)
    'accepted_clock_skew_seconds' => 100
);

then initialize the main Sp class

$sp = new Italia\Spid\Sp($settings);

Don't want the library to generate .key and .crt files for you? Then remove the sp_key_cert_values key from the settings array, or decalre

// $autoconfiguration skips .key/.crt generation if set to false
$sp = new Italia\Spid\Sp($settings, null, $autoconfiguration = false);

Performing login

// shortname of IdP, same as the name of corresponding IdP metadata file, without .xml
$idpName = 'testenv';
// index of assertion consumer service as per the SP metadata (sp_assertionconsumerservice in settings array)
$assertId = 0;
// index of attribute consuming service as per the SP metadata (sp_attributeconsumingservice in settings array)
$attrId = 1;

// Generate the login URL and redirect to the IdP login page
$sp->login($idpName, $assertId, $attrId);

Complete the login operation by calling

$sp->isAuthenticated();

at the assertion consumer service URL.

Then call

$userAttributes = $sp->getAttributes();

to receive an array of the requested user attributes.

Performing logout

Call

// index of single logout service as per the SP metadata (sp_singlelogoutservice in settings array)
$sloId = 0;

$sp->logout($sloId);

The method will redirect to the IdP Single Logout page, or return false if you are not logged in.

Complete API

Method	Description
__contruct($settings, $protocol = null, $autoconfigure = true)	$settings should be based on the example provided in the Usage section. $protocol represents the protocol used for login. At the moment only SAML is supported, and can be selected by either $protocol = 'saml' or the default $protocol = null. $autoconfigure tells the constructor if it should check for .key and .crt files at the specified location from the $settings array and generate them in case they are not found. Set this to false if you wish to generate those manually.
loadIdpFromFile(string $filename)	loads an Idp object by parsing the provided XML at $filename
getIdpList() : array	loads all the Idp objects from the idp_metadata_folder provided in settings
getIdp(string $filename)	alias of loadIdpFromFile
getSPMetadata() : string	returns the SP metadata as a string
login(string $idpFilename, int $assertID, int $attrID, $level = 1, string $redirectTo = null, $shouldRedirect = true)	login with REDIRECT binding. Use $idpFilename to select in IdP for login by indicating the name (without extension) of an XML file in your idp_metadata_folder. $assertID and $attrID indicate respectively the array index of sp_assertionconsumerservice and sp_attributeconsumingservice provided in settings. Optional parameters: $level for SPID authentication level (1, 2 or 3), $redirectTo to indicate an url to redirect to after login, $shouldRedirect to indicate if the login function should automatically redirect to the IdP or should return the login url as a string
loginPost(string $idpName, int $ass, int $attr, $level = 1, string $redirectTo = null, $shouldRedirect = true)	like login, but uses POST binding
logout(int $slo, string $redirectTo = null, $shouldRedirect = true)	logout with REDIRECT binding. $slo indicates the array index of the sp_singlelogoutservice provided in settings. Optional parameters: $redirectTo to indicate an url to redirect to after login, $shouldRedirect to indicate if the login function should automatically redirect to the IdP or should return the login url as a string
logoutPost(int $slo, string $redirectTo = null, $shouldRedirect = true)	like logout, but uses POST binding
isAuthenticated() : bool	checks if the user is authenticated. This method MUST be called after login and logout to finalize the operation.
getAttributes() : array	If you requested attributes with an attribute consuming service during login, this method will return them in array format

Example

A basic demo application is provided in the example/ directory of this repository.

/example and /tests folders are NOT provided with the production version from packagist, remember to require the dev-develop version or just clone this repository (advised)

To try it out:

1. Generate a test certificate and key pair with:

   openssl req -x509 -nodes -sha256 -days 365 -newkey rsa:2048 -subj "/C=IT/ST=Italy/L=Milan/O=myservice/CN=localhost" -keyout sp.key -out sp.crt

2. Adapt the hostname of the SP changing the $base variable in the example/index.php file; the browser you'll be testing from must be able to resolve the FQDN (the default is https://sp.example.com). Using HTTPS is strongly suggested.

3. Configure and install the test IdP spid-testenv2

4. Serve the example dir from your preferred webserver

5. Visit https://sp.example.com/metadata to get the SP metadata, then copy these over to the IdP and register the SP with the IdP

6. Visit https://idp.example.com/metadata to get the IdP metadata, then save it as example/idp_metadata/testenv.xml to register the IdP with the SP

7. Visit: https://sp.example.com and click login.

Demo application

A Docker-based demo application is available at https://github.com/simevo/spid-php-lib-example.

Features

• provides a lean implementation without relying on external SAML packages
• routing-agnostic, can be integrated in any web framework / CMS
• uses a session to store the authentication result and the received attributes
• does not currently support Attribute Authority (AA)

Compliance with SPID regulations (for Service Providers)
Metadata:
parsing of IdP XML metadata (1.2.2.4)	✓
support for multiple signing certificates in IdP XML metadata (1.2.2.4)
parsing of AA XML metadata (2.2.4)
SP XML metadata generation (1.3.2)	✓
AuthnRequest generation (1.2.2.1):
generation of AuthnRequest XML	✓
HTTP-Redirect binding	✓
HTTP-POST binding	✓
AssertionConsumerServiceURL customization	The library uses AssertionConsumerServiceIndex customization which is preferred
AssertionConsumerServiceIndex customization	✓
AttributeConsumingServiceIndex customization	✓
AuthnContextClassRef (SPID level) customization	✓
RequestedAuthnContext/@Comparison customization	✓
RelayState customization (1.2.2)	✓
Response/Assertion parsing
verification of Signature value (if any)	✓
verification of Signature certificate (if any) against IdP/AA metadata	✓
verification of Assertion/Signature value	✓
verification of Assertion/Signature certificate against IdP/AA metadata	✓
verification of SubjectConfirmationData/@Recipient	✓
verification of SubjectConfirmationData/@NotOnOrAfter	✓
verification of SubjectConfirmationData/@InResponseTo	✓
verification of Issuer	✓
verification of Assertion/Issuer	✓
verification of Destination	✓
verification of Conditions/@NotBefore	✓
verification of Conditions/@NotOnOrAfter	✓
verification of Audience	✓
parsing of Response with no Assertion (authentication/query failure)	✓
parsing of failure StatusCode (Requester/Responder)	✓
Response/Assertion parsing for SSO (1.2.1, 1.2.2.2, 1.3.1):
parsing of NameID	✓
parsing of AuthnContextClassRef (SPID level)	✓
parsing of attributes	✓
Response/Assertion parsing for attribute query (2.2.2.2, 2.3.1):
parsing of attributes
LogoutRequest generation (for SP-initiated logout):
generation of LogoutRequest XML	✓
HTTP-Redirect binding	✓
HTTP-POST binding	✓
LogoutResponse parsing (for SP-initiated logout):
parsing of LogoutResponse XML	✓
verification of Response/Signature value (if any)	✓
verification of Response/Signature certificate (if any) against IdP metadata	✓
verification of Issuer	✓
verification of Destination	✓
PartialLogout detection	pending, see: #46
LogoutRequest parsing (for third-party-initiated logout):
parsing of LogoutRequest XML	✓
verification of Response/Signature value (if any)	✓
verification of Response/Signature certificate (if any) against IdP metadata	✓
verification of Issuer	✓
verification of Destination	✓
parsing of NameID	✓
LogoutResponse generation (for third-party-initiated logout):
generation of LogoutResponse XML	✓
HTTP-Redirect binding	✓
HTTP-POST binding	✓
PartialLogout customization	pending, see: #46
AttributeQuery generation (2.2.2.1):
generation of AttributeQuery XML
SOAP binding (client)

More features

• Generation of SPID button markup

Troubleshooting

It is advised to install a browser plugin to trace SAML messages:

• Firefox:

  • SAML-tracer by Olav Morken, Jaime Perez
  • SAML Message Decoder by Magnus Suther

• Chrome/Chromium:

  • SAML Message Decoder by Magnus Suther
  • SAML Chrome Panel by MLai
  • SAML DevTools extension by stefan.rasmusson.as

In addition, you can use the SAML Developer Tools provided by onelogin to understand what is going on

Testing

To test and lint this package you must place yourself in its root directory, then follow the provided instructions.

Assuming you followed the installation instructions with composer, simply do:

cd vendor/italia/spid-php-lib

Unit tests

Install prerequisites with composer, generate key and certificate for the SP and download the metadata for all current production IdPs with:

composer install
bin/download_idp_metadata.php example/idp_metadata

then launch the unit tests with PHPunit:

./vendor/bin/phpunit --stderr --testdox tests

Linting

This project complies with the PSR-2: Coding Style Guide.

Make sure you are in the package directory, then lint the code with:

./vendor/bin/phpcs --standard=PSR2 xxx.php

Contributing

For your contributions please use the git-flow workflow.

See also

• SPID page on Developers Italia

Authors

Lorenzo Cattaneo and Paolo Greppi, simevo s.r.l.

License

Copyright (c) 2018-2020, Developers Italia

License: BSD 3-Clause, see LICENSE file.