CPS-175

[CPS-175](https://workivate.atlassian.net/browse/CPS-175)

Merge upstream for latest stable changes

Author: grahami

.github/workflows/php-package.yml

@@ -0,0 +1,54 @@
+# This workflow will install PHP dependencies, run tests and lint with a variety of PHP versions
+# For more information see: https://github.com/marketplace/actions/setup-php-action
+
+name: php-saml 4.x package
+
+on:
+  push:
+    branches: [ 4.* ]
+  pull_request:
+    branches: [ 4.* ]
+
+jobs:
+  test:
+    runs-on: ${{ matrix.operating-system }}
+    strategy:
+      fail-fast: false
+      matrix:
+        operating-system: ['ubuntu-latest']
+        php-versions: [7.3, 7.4, 8.0, 8.1]
+    steps:
+      - name: Setup PHP, with composer and extensions
+        uses: shivammathur/setup-php@v2 #https://github.com/shivammathur/setup-php
+        with:
+          php-version: ${{ matrix.php-versions }}
+          extensions: mbstring, intl, mcrypt, xml
+          tools: composer:v2
+          ini-values: post_max_size=256M, max_execution_time=180
+          coverage: xdebug
+
+      - name: Set git to use LF
+        run: |
+          git config --global core.autocrlf false
+          git config --global core.eol lf
+      - uses: actions/checkout@v2
+
+      - name: Validate composer.json and composer.lock
+        run: composer validate
+
+      - name: Install Composer dependencies
+        run: |
+          composer self-update
+          composer install --prefer-source --no-interaction
+      - name: Syntax check PHP
+        run: |
+          php vendor/bin/phpcpd --exclude tests --exclude vendor .
+          php vendor/bin/phploc src/.
+          mkdir -p tests/build/dependences
+          php vendor/bin/pdepend --summary-xml=tests/build/logs/dependence-summary.xml --jdepend-chart=tests/build/dependences/jdepend.svg --overview-pyramid=tests/build/dependences/pyramid.svg  src/.
+ 
+      - name: PHP Code Sniffer
+        run: php vendor/bin/phpcs --standard=tests/ZendModStandard src/Saml2 demo1 demo2 endpoints tests/src
+    
+      - name: Run unit tests
+        run: vendor/bin/phpunit --verbose --debug

README.md

@@ -148,6 +148,37 @@ environment is not secure and will be exposed to attacks.
 
 In production also we highly recommended to register on the settings the IdP certificate instead of using the fingerprint method. The fingerprint, is a hash, so at the end is open to a collision attack that can end on a signature validation bypass. Other SAML toolkits deprecated that mechanism, we maintain it for compatibility and also to be used on test environment.
 
+
+### Avoiding Open Redirect attacks ###
+
+Some implementations uses the RelayState parameter as a way to control the flow when SSO and SLO succeeded. So basically the
+user is redirected to the value of the RelayState.
+
+If you are using Signature Validation on the HTTP-Redirect binding, you will have the RelayState value integrity covered, otherwise, and
+on HTTP-POST binding, you can't trust the RelayState so before
+executing the validation, you need to verify that its value belong
+a trusted and expected URL.
+
+Read more about Open Redirect [CWE-601](https://cwe.mitre.org/data/definitions/601.html).
+
+
+### Avoiding Reply attacks ###
+
+A reply attack is basically try to reuse an intercepted valid SAML Message in order to impersonate a SAML action (SSO or SLO).
+
+SAML Messages have a limited timelife (NotBefore, NotOnOrAfter) that
+make harder this kind of attacks, but they are still possible.
+
+In order to avoid them, the SP can keep a list of SAML Messages or Assertion IDs alredy valdidated and processed. Those values only need
+to be stored the amount of time of the SAML Message life time, so
+we don't need to store all processed message/assertion Ids, but the most recent ones.
+
+The OneLogin_Saml2_Auth class contains the [getLastRequestID](https://github.com/onelogin/php-saml/blob/b8214b74dd72960fa6aa88ab454667c64cea935c/src/Saml2/Auth.php#L657), [getLastMessageId](https://github.com/onelogin/php-saml/blob/b8214b74dd72960fa6aa88ab454667c64cea935c/src/Saml2/Auth.php#L762) and [getLastAssertionId](https://github.com/onelogin/php-saml/blob/b8214b74dd72960fa6aa88ab454667c64cea935c/src/Saml2/Auth.php#L770) methods to retrieve the IDs
+
+Checking that the ID of the current Message/Assertion does not exists in the list of the ones already processed will prevent reply
+attacks.
+
+
 Getting started
 ---------------
 
@@ -754,6 +785,8 @@ $_SESSION['samlNameidSPNameQualifier'] = $auth->getNameIdSPNameQualifier();
 $_SESSION['samlSessionIndex'] = $auth->getSessionIndex();
 
 if (isset($_POST['RelayState']) && OneLogin\Saml2\Utils::getSelfURL() != $_POST['RelayState']) {
+    // To avoid 'Open Redirect' attacks, before execute the
+    // redirection confirm the value of $_POST['RelayState'] is a // trusted URL.
     $auth->redirectTo($_POST['RelayState']);
 }
 
@@ -1092,6 +1125,8 @@ if (isset($_GET['sso'])) {    // SSO action.  Will send an AuthNRequest to the I
 
     $_SESSION['samlUserdata'] = $auth->getAttributes(); // Retrieves user data
     if (isset($_POST['RelayState']) && OneLogin\Saml2\Utils::getSelfURL() != $_POST['RelayState']) {
+        // To avoid 'Open Redirect' attacks, before execute the
+        // redirection confirm the value of $_POST['RelayState'] is a // trusted URL.
         $auth->redirectTo($_POST['RelayState']);  // Redirect if there is a
     }                                             // relayState set
 } else if (isset($_GET['sls'])) {   // Single Logout Service
@@ -1100,7 +1135,7 @@ if (isset($_GET['sso'])) {    // SSO action.  Will send an AuthNRequest to the I
     if (empty($errors)) {
         echo '<p>Sucessfully logged out</p>';
     } else {
-        echo '<p>' . implode(', ', $errors) . '</p>';
+        echo '<p>' . htmlentities(implode(', ', $errors)) . '</p>';
     }
 }
 
@@ -1384,6 +1419,8 @@ Auxiliary class that contains several methods to retrieve and process IdP metada
  * `parseXML` - Get IdP Metadata Info from XML.
  * `injectIntoSettings` - Inject metadata info into php-saml settings array.
 
+The class does not validate in any way the URL that is introduced on methods like parseRemoteXML in order to retrieve the remove XML. Usually is the same administrator that handles the Service Provider the ones that set the URL that should belong to a trusted third-party IdP.
+But there are other scenarios, like a SAAS app where the administrator of the app delegates on other administrators. In such case, extra protection should be taken in order to validate such URL inputs and avoid attacks like SSRF.
 
 For more info, look at the source code; each method is documented and details
 about what it does and how to use it are provided. Make sure to also check the doc folder where

composer.json

@@ -19,13 +19,17 @@
         "robrichards/xmlseclibs": ">=3.1.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.5.2",
+        "phpunit/phpunit": "^9.5",
         "php-coveralls/php-coveralls": "^2.0",
+        "sebastian/phpcpd": "^4.0 || ^5.0 || ^6.0 ",
+        "phploc/phploc": "^4.0 || ^5.0 || ^6.0 || ^7.0",
         "pdepend/pdepend": "^2.8.0",
-        "squizlabs/php_codesniffer": "^3.5.8",
-        "vimeo/psalm": "^4.6"
+        "squizlabs/php_codesniffer": "^3.5.8"
     },
     "config": {
+        "platform": {
+            "php": "7.3.0"
+        },
         "optimize-autoloader": true,
         "sort-packages": true
     },