Merge pull request #36 from pdsinterop/fix/dpop

Change TokenGenerator::generateIdToken() to make DPOP optional when needed.

Author: ylebre

src/TokenGenerator.php

@@ -52,37 +52,45 @@ public function generateRegistrationAccessToken($clientId, $privateKey) {
 		return $token->toString();
 	}
 
-	public function generateIdToken($accessToken, $clientId, $subject, $nonce, $privateKey, $dpop, $now=null) {
+    /**
+     * Please note that the DPOP _is not_ required when requesting a token to
+     * authorize a client but the DPOP _is_ required when requesting an access
+     * token.
+     */
+	public function generateIdToken($accessToken, $clientId, $subject, $nonce, $privateKey, $dpop=null, $now=null) {
 		$issuer = $this->config->getServer()->get(OidcMeta::ISSUER);
 
 		$tokenHash = $this->generateTokenHash($accessToken);
 
-                // Create JWT
-                $jwtConfig = Configuration::forSymmetricSigner(new Sha256(), InMemory::plainText($privateKey));
-                $now = $now ?? new DateTimeImmutable();
-                $useAfter = $now->sub(new \DateInterval('PT1S'));
-
-                $expire = $now->add($this->validFor);
-
-        $jkt = $this->makeJwkThumbprint($dpop);
-
-                $token = $jwtConfig->builder()
-                        ->issuedBy($issuer)
-                        ->permittedFor($clientId)
-                        ->issuedAt($now)
-                        ->canOnlyBeUsedAfter($useAfter)
-                        ->expiresAt($expire)
-                        ->withClaim("azp", $clientId)
-                        ->relatedTo($subject)
-                        ->identifiedBy($this->generateJti())
-                        ->withClaim("nonce", $nonce)
-                        ->withClaim("at_hash", $tokenHash) //FIXME: at_hash should only be added if the response_type is a token
-                        ->withClaim("c_hash", $tokenHash) // FIXME: c_hash should only be added if the response_type is a code
-                        ->withClaim("cnf", array(
-                                "jkt" => $jkt,
-                        ))
-                        ->getToken($jwtConfig->signer(), $jwtConfig->signingKey());
-                return $token->toString();
+		// Create JWT
+		$jwtConfig = Configuration::forSymmetricSigner(new Sha256(), InMemory::plainText($privateKey));
+		$now = $now ?? new DateTimeImmutable();
+		$useAfter = $now->sub(new \DateInterval('PT1S'));
+
+		$expire = $now->add($this->validFor);
+
+		$token = $jwtConfig->builder()
+			->issuedBy($issuer)
+			->permittedFor($clientId)
+			->issuedAt($now)
+			->canOnlyBeUsedAfter($useAfter)
+			->expiresAt($expire)
+			->withClaim("azp", $clientId)
+			->relatedTo($subject)
+			->identifiedBy($this->generateJti())
+			->withClaim("nonce", $nonce)
+			->withClaim("at_hash", $tokenHash) //FIXME: at_hash should only be added if the response_type is a token
+			->withClaim("c_hash", $tokenHash) // FIXME: c_hash should only be added if the response_type is a code
+		;
+
+		if ($dpop !== null) {
+			$jkt = $this->makeJwkThumbprint($dpop);
+			$token = $token->withClaim("cnf", [
+				"jkt" => $jkt,
+			]);
+		}
+
+		return $token->getToken($jwtConfig->signer(), $jwtConfig->signingKey())->toString();
 	}
 
 	public function respondToRegistration($registration, $privateKey) {

tests/unit/TokenGeneratorTest.php

@@ -278,27 +278,70 @@ final public function testIdTokenGenerationWithoutPrivateKey(): void
     }
 
     /**
-     * @testdox Token Generator SHOULD complain WHEN asked to generate a IdToken without dpopKey
+     * @testdox Token Generator SHOULD generate a token without Confirmation JWT Thumbprint (CNF JKT) WHEN asked to generate a IdToken without dpopKey
      *
      * @covers ::generateIdToken
      */
     final public function testIdTokenGenerationWithoutDpopKey(): void
     {
-        $tokenGenerator = $this->createTokenGenerator();
+        $validFor = new \DateInterval('PT1S');
 
-        $this->expectArgumentCountError(6);
+        $tokenGenerator = $this->createTokenGenerator($validFor);
 
-        $tokenGenerator->generateIdToken(
+
+        $mockServer = $this->getMockBuilder(ServerInterface::class)
+            ->disableOriginalConstructor()
+            ->getMock()
+        ;
+
+        $this->mockConfig->expects($this->once())
+            ->method('getServer')
+            ->willReturn($mockServer)
+        ;
+
+        $mockServer->expects($this->once())
+            ->method('get')
+            ->with(OidcMeta::ISSUER)
+            ->willReturn('mock issuer')
+        ;
+
+        $privateKey = file_get_contents(__DIR__.'/../fixtures/keys/private.key');
+
+        $now = new \DateTimeImmutable('1234-01-01 12:34:56.789');
+
+        $token = $tokenGenerator->generateIdToken(
             'mock access token',
             'mock clientId',
             'mock subject',
             'mock nonce',
-            'mock private key'
+            $privateKey,
+            null,
+            $now,
         );
+
+        $this->assertJwtEquals([
+            [
+                'typ' => 'JWT',
+                'alg' => 'RS256',
+            ],
+            [
+                'at_hash' => '1EZBnvsFWlK8ESkgHQsrIQ',
+                'aud' => 'mock clientId',
+                'azp' => 'mock clientId',
+                'c_hash' => '1EZBnvsFWlK8ESkgHQsrIQ',
+                'exp' => -23225829903.789,
+                'iat' => -23225829904.789,
+                'iss' => 'mock issuer',
+                'jti' => '4dc20036dbd8313ed055',
+                'nbf' => -23225829905.789,
+                'nonce' => 'mock nonce',
+                'sub' => 'mock subject',
+            ],
+        ], $token);
     }
 
     /**
-     * @testdox Token Generator SHOULD return a IdToken WHEN asked to generate a IdToken with clientId and privateKey
+     * @testdox Token Generator SHOULD return a IdToken with a Confirmation JWT Thumbprint (CNF JKT) WHEN asked to generate a IdToken with clientId and privateKey and DPOP
      *
      * @covers ::generateIdToken
      *