From ad1a2dacd150a559f18cc3f1bff730abff9f82ba Mon Sep 17 00:00:00 2001
From: Hoang Pham <hoangmaths96@gmail.com>
Date: Fri, 28 Jun 2024 18:51:10 +0700
Subject: [PATCH] feat: IdP Post

---
 lib/Controller/SAMLController.php | 41 +++++++++++++++++++++++++------
 templates/login_post.php          | 15 +++++++++++
 2 files changed, 49 insertions(+), 7 deletions(-)
 create mode 100644 templates/login_post.php

diff --git a/lib/Controller/SAMLController.php b/lib/Controller/SAMLController.php
index 984cc660..3860927d 100644
--- a/lib/Controller/SAMLController.php
+++ b/lib/Controller/SAMLController.php
@@ -6,6 +6,7 @@
 
 namespace OCA\User_SAML\Controller;
 
+use Exception;
 use Firebase\JWT\JWT;
 use Firebase\JWT\Key;
 use OC\Core\Controller\ClientFlowLoginController;
@@ -177,9 +178,9 @@ protected function assertGroupMemberships(): void {
 	 * @OnlyUnauthenticatedUsers
 	 * @NoCSRFRequired
 	 *
-	 * @throws \Exception
+	 * @throws Exception
 	 */
-	public function login(int $idp = 1): Http\RedirectResponse {
+	public function login(int $idp = 1) {
 		$originalUrl = (string)$this->request->getParam('originalUrl', '');
 		if (!$this->trustedDomainHelper->isTrustedUrl($originalUrl)) {
 			$originalUrl = '';
@@ -192,6 +193,31 @@ public function login(int $idp = 1): Http\RedirectResponse {
 
 				$returnUrl = $originalUrl ?: $this->urlGenerator->linkToRouteAbsolute('user_saml.SAML.login');
 				$ssoUrl = $auth->login($returnUrl, [], false, false, true);
+
+				$method = $this->request->getParam('method', 'get');
+				if ($method === 'post') {
+					$query = parse_url($ssoUrl, PHP_URL_QUERY);
+					parse_str($query, $params);
+					$samlRequest = $params['SAMLRequest'];
+					$relayState = $params['RelayState'] ?? '';
+					$sigAlg = $params['SigAlg'] ?? '';
+					$signature = $params['Signature'] ?? '';
+
+					$nonce = base64_encode(random_bytes(16));
+					$ssoUrl = explode('?', $ssoUrl)[0];
+
+					$response = new Http\TemplateResponse($this->appName, 'login_post', [
+						'ssoUrl' => $ssoUrl,
+						'samlRequest' => $samlRequest,
+						'relayState' => $relayState,
+						'sigAlg' => $sigAlg,
+						'signature' => $signature,
+						'nonce' => $nonce,
+					], 'guest');
+					$response->addHeader('Content-Security-Policy', "script-src 'self' 'nonce-$nonce' 'strict-dynamic' 'unsafe-eval';");
+					return $response;
+				}
+
 				$response = new Http\RedirectResponse($ssoUrl);
 
 				// Small hack to make user_saml work with the loginflows
@@ -257,7 +283,7 @@ public function login(int $idp = 1): Http\RedirectResponse {
 				}
 				break;
 			default:
-				throw new \Exception(
+				throw new Exception(
 					sprintf(
 						'Type of "%s" is not supported for user_saml',
 						$type
@@ -314,7 +340,7 @@ public function assertionConsumerService(): Http\RedirectResponse {
 		// Decrypt and deserialize
 		try {
 			$cookie = $this->crypto->decrypt($cookie);
-		} catch (\Exception) {
+		} catch (Exception) {
 			$this->logger->debug('Could not decrypt SAML cookie', ['app' => 'user_saml']);
 			return new Http\RedirectResponse($this->urlGenerator->getAbsoluteURL('/'));
 		}
@@ -394,7 +420,7 @@ public function assertionConsumerService(): Http\RedirectResponse {
 			}
 		} catch (NoUserFoundException) {
 			throw new \InvalidArgumentException('User "' . $this->userBackend->getCurrentUserId() . '" is not valid');
-		} catch (\Exception $e) {
+		} catch (Exception $e) {
 			$this->logger->critical($e->getMessage(), ['exception' => $e, 'app' => $this->appName]);
 			$response = new Http\RedirectResponse($this->urlGenerator->linkToRouteAbsolute('user_saml.SAML.notProvisioned'));
 			$response->invalidateCookie('saml_data');
@@ -450,7 +476,7 @@ public function singleLogoutService(): Http\RedirectResponse {
 
 				$idp = $decoded['idp'] ?? null;
 				$pass = true;
-			} catch (\Exception) {
+			} catch (Exception) {
 			}
 		} else {
 			// standard request : need read CRSF check
@@ -617,7 +643,8 @@ private function getSSOUrl(string $redirectUrl, string $idp): string {
 			[
 				'requesttoken' => $csrfToken->getEncryptedValue(),
 				'originalUrl' => $originalUrl,
-				'idp' => $idp
+				'idp' => $idp,
+				'method' => 'post',
 			]
 		);
 
diff --git a/templates/login_post.php b/templates/login_post.php
new file mode 100644
index 00000000..1fe3f59d
--- /dev/null
+++ b/templates/login_post.php
@@ -0,0 +1,15 @@
+<form action="<?= $_['ssoUrl'] ?>" method="post">
+	<input type="hidden" name="SAMLRequest" value="<?= $_['samlRequest'] ?>" />
+	<input type="hidden" name="RelayState" value="<?=$_['relayState'] ?>" />
+	<input type="hidden" name="SigAlg" value="<?= $_['sigAlg'] ?>" />
+	<input type="hidden" name="Signature" value="<?= $_['signature'] ?>" />
+	<noscript>
+		<p>JavaScript is disabled. Click the button below to continue.</p>
+		<input type="submit" value="Continue" />
+	</noscript>
+</form>
+<script nonce="<?= $_['nonce'] ?>">
+	document.addEventListener('DOMContentLoaded', function() {
+		document.forms[0].submit()
+	})
+</script>