WIP

Signed-off-by: Nguyen Van Nguyen <nguyennv1981@gmail.com>

src/Message/LiteralMessage.php

@@ -35,6 +35,7 @@
     LiteralDataInterface,
     LiteralMessageInterface,
     NotationDataInterface,
+    PacketListInterface,
     PrivateKeyInterface,
     SessionKeyInterface,
     SignatureInterface,
@@ -118,20 +119,21 @@ public static function generateSessionKey(
     ): SessionKeyInterface {
         $symmetric = $defaultSymmetric;
         if (count($encryptionKeys) > 0) {
-            $preferredSymmetrics = [
-                SymmetricAlgorithm::Aes128,
-                SymmetricAlgorithm::Aes192,
-                SymmetricAlgorithm::Aes256,
-            ];
+            $preferredSymmetrics = [];
             foreach ($encryptionKeys as $key) {
-                $preferredSymmetrics = array_filter(
-                    $preferredSymmetrics,
-                    static fn ($symmetric) => in_array(
-                        $symmetric,
-                        $key->getPreferredSymmetrics(),
-                        true
-                    )
-                );
+                if (empty($preferredSymmetrics)) {
+                    $preferredSymmetrics = $key->getPreferredSymmetrics();
+                }
+                else {
+                    $preferredSymmetrics = array_filter(
+                        $preferredSymmetrics,
+                        static fn ($symmetric) => in_array(
+                            $symmetric,
+                            $key->getPreferredSymmetrics(),
+                            true
+                        )
+                    );
+                }
             }
             if (count($encryptionKeys) > 0) {
                 $symmetric = reset($preferredSymmetrics);
@@ -175,19 +177,19 @@ public static function generateSessionKey(
      * @param SessionKeyInterface $sessionKey
      * @param array $encryptionKeys
      * @param array $passwords
-     * @return array
+     * @return PacketListInterface
      */
     public static function encryptSessionKey(
         SessionKeyInterface $sessionKey,
         array $encryptionKeys = [],
         array $passwords = []
-    ): array {
+    ): PacketListInterface {
         if (empty($encryptionKeys) && empty($passwords)) {
             throw new \InvalidArgumentException(
                 "No encryption keys or passwords provided."
             );
         }
-        return [
+        return new PacketList([
             ...array_map(
                 static fn (
                     $key
@@ -208,7 +210,7 @@ public static function encryptSessionKey(
                 ),
                 $passwords
             ), // skesk packets
-        ];
+        ]);
     }
 
     /**
@@ -378,7 +380,7 @@ public function encrypt(
                     $sessionKey,
                     $encryptionKeys,
                     $passwords
-                ),
+                )->getPackets(),
                 SymEncryptedIntegrityProtectedData::encryptPacketsWithSessionKey(
                     $sessionKey,
                     $packetList,

src/OpenPGP.php

@@ -558,13 +558,13 @@ public static function generateSessionKey(
      * @param Type\SessionKeyInterface $sessionKey
      * @param array $encryptionKeys
      * @param array $passwords
-     * @return array
+     * @return Type\PacketListInterface
      */
     public static function encryptSessionKey(
         Type\SessionKeyInterface $sessionKey,
         array $encryptionKeys = [],
         array $passwords = []
-    ): array
+    ): Type\PacketListInterface
     {
         return Message\LiteralMessage::encryptSessionKey(
             $sessionKey, $encryptionKeys, $passwords
@@ -580,7 +580,7 @@ public static function encryptSessionKey(
      * @param array $passwords
      * @return Type\SessionKeyInterface
      */
-    private function decryptSessionKey(
+    public static function decryptSessionKey(
         Type\PacketListInterface $packetList,
         array $decryptionKeys = [],
         array $passwords = []

tests/Message/SessionKeyTest.php

@@ -0,0 +1,168 @@
+<?php declare(strict_types=1);
+
+namespace OpenPGP\Tests\Message;
+
+use OpenPGP\OpenPGP;
+use OpenPGP\Enum\{AeadAlgorithm, SymmetricAlgorithm};
+use OpenPGP\Tests\OpenPGPTestCase;
+
+/**
+ * Testcase class for session key.
+ */
+class SessionKeyTest extends OpenPGPTestCase
+{
+    const PASSPHRASE = "password";
+
+    private static string $rfc9580PublicKey = <<<EOT
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+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+-----END PGP PUBLIC KEY BLOCK-----
+EOT;
+
+    private static string $rfc9580PrivateKey = <<<EOT
+-----BEGIN PGP PRIVATE KEY BLOCK-----
+
+xUsGY4d/4xsAAAAg+U2nu0jWCmHlZ3BqZYfQMxmZu52JGggkLq2EVD34laMAGXKB
+exK+cH6NX1hs5hNhIB00TrJmosgv3mg1ditlsLfCsQYfGwoAAABCBYJjh3/jAwsJ
+BwUVCg4IDAIWAAKbAwIeCSIhBssYbE8GCaaX5NUt+mxyKwwfHifBilZwj2Ul7Ce6
+2azJBScJAgcCAAAAAK0oIBA+LX0ifsDm185Ecds2v8lwgyU2kCcUmKfvBXbAf6rh
+RYWzuQOwEn7E/aLwIwRaLsdry0+VcallHhSu4RN6HWaEQsiPlR4zxP/TP7mhfVEe
+7XWPxtnMUMtf15OyA51YBMdLBmOHf+MZAAAAIIaTJINn+eUBXbki+PSAld2nhJh/
+LVmFsS+60WyvXkQ1AE1gCk95TUR3XFeibg/u/tVY6a//1q0NWC1X+yui3O24wpsG
+GBsKAAAALAWCY4d/4wKbDCIhBssYbE8GCaaX5NUt+mxyKwwfHifBilZwj2Ul7Ce6
+2azJAAAAAAQBIKbpGG2dWTX8j+VjFM21J0hqWlEg+bdiojWnKfA5AQpWUWtnNwDE
+M0g12vYxoWM8Y81W+bHBw805I8kWVkXU6vFOi+HWvv/ira7ofJu16NnoUkhclkUr
+k0mXubZvyl4GBg==
+-----END PGP PRIVATE KEY BLOCK-----
+EOT;
+
+    private static string $alicePublicKey = <<<EOT
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+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+=iIGO
+-----END PGP PUBLIC KEY BLOCK-----
+EOT;
+
+    private static string $alicePrivateKey = <<<EOT
+-----BEGIN PGP PRIVATE KEY BLOCK-----
+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+=3GfK
+-----END PGP PRIVATE KEY BLOCK-----
+EOT;
+
+    public function testGenerateSessionKey()
+    {
+        $sessionKey = OpenPGP::generateSessionKey([
+            OpenPGP::readPublicKey(self::$rfc9580PublicKey),
+        ]);
+        $this->assertSame(
+            $sessionKey->getSymmetric(),
+            SymmetricAlgorithm::Aes256
+        );
+        $this->assertSame(
+            $sessionKey->getAead(),
+            AeadAlgorithm::Ocb
+        );
+
+        $sessionKey = OpenPGP::generateSessionKey([
+            OpenPGP::readPublicKey(self::$alicePublicKey),
+        ]);
+        $this->assertSame(
+            $sessionKey->getSymmetric(),
+            SymmetricAlgorithm::Aes256
+        );
+        $this->assertTrue(empty($sessionKey->getAead()));
+
+        $sessionKey = OpenPGP::generateSessionKey([
+            OpenPGP::readPublicKey(self::$rfc9580PublicKey),
+            OpenPGP::readPublicKey(self::$alicePublicKey),
+        ]);
+        $this->assertSame(
+            $sessionKey->getSymmetric(),
+            SymmetricAlgorithm::Aes256
+        );
+        $this->assertTrue(empty($sessionKey->getAead()));
+    }
+
+    public function testSessionKeyEncryption()
+    {
+        $sessionKey = OpenPGP::generateSessionKey([
+            OpenPGP::readPublicKey(self::$rfc9580PublicKey),
+            OpenPGP::readPublicKey(self::$alicePublicKey),
+        ]);
+
+        $eskPackets = OpenPGP::encryptSessionKey(
+            $sessionKey,
+            [
+                OpenPGP::readPublicKey(self::$rfc9580PublicKey),
+                OpenPGP::readPublicKey(self::$alicePublicKey),
+            ],
+            [self::PASSPHRASE]
+        );
+
+        $decryptSessionKey = OpenPGP::decryptSessionKey($eskPackets, [
+            OpenPGP::readPrivateKey(self::$rfc9580PrivateKey)
+        ]);
+        $this->assertSame(
+            $sessionKey->getEncryptionKey(),
+            $decryptSessionKey->getEncryptionKey()
+        );
+        $this->assertSame(
+            $sessionKey->getSymmetric(),
+            $decryptSessionKey->getSymmetric()
+        );
+
+        $decryptSessionKey = OpenPGP::decryptSessionKey($eskPackets, [
+            OpenPGP::readPrivateKey(self::$alicePrivateKey)
+        ]);
+        $this->assertSame(
+            $sessionKey->getEncryptionKey(),
+            $decryptSessionKey->getEncryptionKey()
+        );
+        $this->assertSame(
+            $sessionKey->getSymmetric(),
+            $decryptSessionKey->getSymmetric()
+        );
+
+        $decryptSessionKey = OpenPGP::decryptSessionKey($eskPackets, [], [
+            self::PASSPHRASE
+        ]);
+        $this->assertSame(
+            $sessionKey->getEncryptionKey(),
+            $decryptSessionKey->getEncryptionKey()
+        );
+        $this->assertSame(
+            $sessionKey->getSymmetric(),
+            $decryptSessionKey->getSymmetric()
+        );
+    }
+}