singleloginsystem/app/Services/SamlIdpService.php
2026-05-27 13:10:51 +00:00

405 lines
13 KiB
PHP

<?php
declare(strict_types=1);
namespace App\Services;
use App\Models\{ConnectedApp, User};
use DOMDocument;
use DOMElement;
use Exception;
use Illuminate\Support\Facades\File;
use Illuminate\Support\Str;
use RobRichards\XMLSecLibs\{XMLSecurityDSig, XMLSecurityKey};
use RuntimeException;
final class SamlIdpService
{
/**
* Decode and parse an incoming SAMLRequest (GET/POST).
*
* @return array{requestId: string, issuer: string, acsUrl: string}
*
* @throws Exception
*/
public function parseRequest(string $samlRequest): array
{
$decoded = base64_decode($samlRequest, true);
if (false === $decoded) {
throw new Exception('Failed to base64 decode SAMLRequest.');
}
// Try deflated (GET Redirect binding)
$xml = @gzinflate($decoded);
if (false === $xml) {
// Fallback to raw decoded XML (POST binding)
$xml = $decoded;
}
$dom = new DOMDocument();
$dom->preserveWhiteSpace = false;
if (! @$dom->loadXML($xml)) {
throw new Exception('Failed to load SAMLRequest XML.');
}
$issuerNode = $dom
->getElementsByTagNameNS(
'urn:oasis:names:tc:SAML:2.0:assertion',
'Issuer',
)
->item(0);
if (! $issuerNode) {
$issuerNode = $dom->getElementsByTagName('Issuer')->item(0);
}
$issuer = $issuerNode ? mb_trim($issuerNode->nodeValue) : '';
$requestId = $dom->documentElement->getAttribute('ID');
$acsUrl = $dom->documentElement->getAttribute(
'AssertionConsumerServiceURL',
);
return [
'requestId' => $requestId,
'issuer' => $issuer,
'acsUrl' => $acsUrl,
];
}
/**
* Verify if the SAML SP Issuer is registered as a connected app and active.
*/
public function findConnectedApp(string $issuer): ?ConnectedApp
{
return ConnectedApp::query()
->where('settings->saml->entity_id', $issuer)
->first();
}
/**
* Generate the XML SAML metadata for this Identity Provider.
*/
public function generateMetadata(
string $idpEntityId,
string $ssoUrl,
): string {
$certPem = $this->getPublicCertificate();
$certClean = $this->cleanPem($certPem);
$xml = <<<XML
<?xml version="1.0" encoding="UTF-8"?>
<EntityDescriptor entityID="{$idpEntityId}" xmlns="urn:oasis:names:tc:SAML:2.0:metadata">
<IDPSSODescriptor WantAuthnRequestsSigned="false" protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol">
<KeyDescriptor use="signing">
<ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
<ds:X509Data>
<ds:X509Certificate>{$certClean}</ds:X509Certificate>
</ds:X509Data>
</ds:KeyInfo>
</KeyDescriptor>
<SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect" Location="{$ssoUrl}"/>
<SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST" Location="{$ssoUrl}"/>
</IDPSSODescriptor>
</EntityDescriptor>
XML;
return $xml;
}
/**
* Generate a signed SAMLResponse XML for a successful authentication.
*
* @throws Exception
*/
public function generateResponse(
User $user,
ConnectedApp $app,
string $requestId,
string $acsUrl,
): string {
$idpEntityId = route('saml.metadata');
/**
* @var array{
* saml?: array{
* entity_id?: string,
* acs_url?: string
* }
* } $settings
*/
$settings = (array) $app->settings;
$spEntityId = $settings['saml']['entity_id'] ?? $acsUrl;
$responseId = '_'.Str::uuid()->toString();
$assertionId = '_'.Str::uuid()->toString();
$now = time();
$issueInstant = gmdate("Y-m-d\TH:i:s\Z", $now);
$notBefore = gmdate("Y-m-d\TH:i:s\Z", $now - 30); // 30 sec skew tolerance
$expireInstant = gmdate("Y-m-d\TH:i:s\Z", $now + 300); // 5 min validity
$immutableId = $user->immutable_id ?? base64_encode((string) $user->id);
$dom = new DOMDocument('1.0', 'UTF-8');
$dom->preserveWhiteSpace = false;
$response = $dom->createElementNS(
'urn:oasis:names:tc:SAML:2.0:protocol',
'samlp:Response',
);
$response->setAttribute('ID', $responseId);
$response->setAttribute('InResponseTo', $requestId);
$response->setAttribute('Version', '2.0');
$response->setAttribute('IssueInstant', $issueInstant);
$response->setAttribute('Destination', $acsUrl);
$issuer = $dom->createElementNS(
'urn:oasis:names:tc:SAML:2.0:assertion',
'saml:Issuer',
$idpEntityId,
);
$response->appendChild($issuer);
$status = $dom->createElement('samlp:Status');
$statusCode = $dom->createElement('samlp:StatusCode');
$statusCode->setAttribute(
'Value',
'urn:oasis:names:tc:SAML:2.0:status:Success',
);
$status->appendChild($statusCode);
$response->appendChild($status);
$assertion = $dom->createElementNS(
'urn:oasis:names:tc:SAML:2.0:assertion',
'saml:Assertion',
);
$assertion->setAttribute('ID', $assertionId);
$assertion->setAttribute('Version', '2.0');
$assertion->setAttribute('IssueInstant', $issueInstant);
$assertionIssuer = $dom->createElement('saml:Issuer', $idpEntityId);
$assertion->appendChild($assertionIssuer);
// Subject
$subject = $dom->createElement('saml:Subject');
$nameId = $dom->createElement('saml:NameID', $immutableId);
$nameId->setAttribute(
'Format',
'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
);
$subject->appendChild($nameId);
$subjectConfirmation = $dom->createElement('saml:SubjectConfirmation');
$subjectConfirmation->setAttribute(
'Method',
'urn:oasis:names:tc:SAML:2.0:cm:bearer',
);
$subjectConfirmationData = $dom->createElement(
'saml:SubjectConfirmationData',
);
$subjectConfirmationData->setAttribute('InResponseTo', $requestId);
$subjectConfirmationData->setAttribute('NotOnOrAfter', $expireInstant);
$subjectConfirmationData->setAttribute('Recipient', $acsUrl);
$subjectConfirmation->appendChild($subjectConfirmationData);
$subject->appendChild($subjectConfirmation);
$assertion->appendChild($subject);
// Conditions
$conditions = $dom->createElement('saml:Conditions');
$conditions->setAttribute('NotBefore', $notBefore);
$conditions->setAttribute('NotOnOrAfter', $expireInstant);
$audienceRestriction = $dom->createElement('saml:AudienceRestriction');
$audience = $dom->createElement('saml:Audience', $spEntityId);
$audienceRestriction->appendChild($audience);
$conditions->appendChild($audienceRestriction);
$assertion->appendChild($conditions);
// AuthnStatement
$authnStatement = $dom->createElement('saml:AuthnStatement');
$authnStatement->setAttribute('AuthnInstant', $issueInstant);
$authnStatement->setAttribute('SessionIndex', $assertionId);
$authnContext = $dom->createElement('saml:AuthnContext');
$authnContextClassRef = $dom->createElement(
'saml:AuthnContextClassRef',
'urn:oasis:names:tc:SAML:2.0:ac:classes:PasswordProtectedTransport',
);
$authnContext->appendChild($authnContextClassRef);
$authnStatement->appendChild($authnContext);
$assertion->appendChild($authnStatement);
// AttributeStatement (SAML claims)
$attributeStatement = $dom->createElement('saml:AttributeStatement');
// IDPEmail (essential claim for Office 365 mapping to UserPrincipalName)
$this->addAttribute(
$dom,
$attributeStatement,
'IDPEmail',
$user->email,
);
// mail
$this->addAttribute($dom, $attributeStatement, 'mail', $user->email);
// UPN
$this->addAttribute(
$dom,
$attributeStatement,
'http://schemas.xmlsoap.org/ws/2005/05/identity/claims/upn',
$user->email,
);
// displayName
$this->addAttribute(
$dom,
$attributeStatement,
'displayName',
$user->name,
);
// emailaddress (Required by Microsoft SAML 2.0 specifications)
$this->addAttribute(
$dom,
$attributeStatement,
'http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress',
$user->email,
);
$assertion->appendChild($attributeStatement);
$response->appendChild($assertion);
$dom->appendChild($response);
// Sign the assertion node
$this->signAssertion($dom, $assertion);
return base64_encode($dom->saveXML());
}
/**
* Add a simple attribute to SAML AttributeStatement.
*/
private function addAttribute(
DOMDocument $dom,
DOMElement $statement,
string $name,
string $value,
): void {
$attribute = $dom->createElement('saml:Attribute');
$attribute->setAttribute('Name', $name);
$attribute->setAttribute(
'NameFormat',
'urn:oasis:names:tc:SAML:2.0:attrname-format:basic',
);
$val = $dom->createElement(
'saml:AttributeValue',
htmlspecialchars($value, ENT_QUOTES | ENT_XML1, 'UTF-8'),
);
$attribute->appendChild($val);
$statement->appendChild($attribute);
}
/**
* Cryptographically sign the Assertion node in DOMDocument.
*/
private function signAssertion(
DOMDocument $dom,
DOMElement|DOMDocument $assertion,
): void {
$privateKeyPem = $this->getPrivateKey();
$certPem = $this->getPublicCertificate();
// XML Security Signature Setup
$objDSig = new XMLSecurityDSig();
$objDSig->setCanonicalMethod(XMLSecurityDSig::C14N);
// Explicitly designate Assertion ID attribute so xmlseclibs can locate it correctly
$assertion->setIdAttribute('ID', true);
// Add reference to assertion
$objDSig->addReference(
$assertion,
XMLSecurityDSig::SHA256,
[
'http://www.w3.org/2000/09/xmldsig#enveloped-signature',
'http://www.w3.org/2001/10/xml-exc-c14n#',
],
[
'id_name' => 'ID',
],
);
$objKey = new XMLSecurityKey(XMLSecurityKey::RSA_SHA256, [
'type' => 'private',
]);
$objKey->loadKey($privateKeyPem, false);
// Sign the XML
$objDSig->sign($objKey, $assertion);
$objDSig->add509Cert($certPem);
// Enforce SAML Schema order compliance: Signature node must precede Subject.
$signatureNode = $assertion
->getElementsByTagNameNS(
'http://www.w3.org/2000/09/xmldsig#',
'Signature',
)
->item(0);
$subjectNode = $assertion
->getElementsByTagNameNS(
'urn:oasis:names:tc:SAML:2.0:assertion',
'Subject',
)
->item(0);
if ($signatureNode && $subjectNode) {
$assertion->insertBefore($signatureNode, $subjectNode);
}
}
/**
* Load IdP Private Key.
*/
private function getPrivateKey(): string
{
$path = storage_path('app/saml/idp.key');
if (! File::exists($path)) {
throw new RuntimeException(
"SAML private key not found at [{$path}]. Run 'php artisan saml:generate-keys'.",
);
}
return File::get($path);
}
/**
* Load IdP Public Certificate.
*/
private function getPublicCertificate(): string
{
$path = storage_path('app/saml/idp.crt');
if (! File::exists($path)) {
throw new RuntimeException(
"SAML public certificate not found at [{$path}]. Run 'php artisan saml:generate-keys'.",
);
}
return File::get($path);
}
/**
* Helper to clean up PEM certificate for metadata insertion.
*/
private function cleanPem(string $pem): string
{
return str_replace(
[
'-----BEGIN CERTIFICATE-----',
'-----END CERTIFICATE-----',
"\r",
"\n",
' ',
],
'',
$pem,
);
}
}