From 7cf5facae75138f30b91fc54a4b342a9c8efa5d8 Mon Sep 17 00:00:00 2001
From: terrafrost <terrafrost@php.net>
Date: Thu, 8 Aug 2019 08:00:37 -0500
Subject: [PATCH] DH: add Curve25519 unit test based off of RFC7748 test
 vectors

---
 phpseclib/Crypt/EC.php      |  5 +++++
 tests/Unit/Crypt/DHTest.php | 26 ++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/phpseclib/Crypt/EC.php b/phpseclib/Crypt/EC.php
index 3366824a..f9e9b59d 100644
--- a/phpseclib/Crypt/EC.php
+++ b/phpseclib/Crypt/EC.php
@@ -264,6 +264,11 @@ abstract class EC extends AsymmetricKey
             return $this->curveName;
         }
 
+        if ($this->curve instanceof MontgomeryCurve) {
+            $this->curveName = $this->curve instanceof Curve25519 ? 'Curve25519' : 'Curve448';
+            return $this->curveName;
+        }
+
         if ($this->curve instanceof TwistedEdwardsCurve) {
             $this->curveName = $this->curve instanceof Ed25519 ? 'Ed25519' : 'Ed448';
             return $this->curveName;
diff --git a/tests/Unit/Crypt/DHTest.php b/tests/Unit/Crypt/DHTest.php
index 6c8fee0c..2c90185f 100644
--- a/tests/Unit/Crypt/DHTest.php
+++ b/tests/Unit/Crypt/DHTest.php
@@ -200,4 +200,30 @@ Q3ADAIcv9LEmTBnSAOsCs1K9ExAmSv/T2/4+9dW28UYb+p/uV477d1wf+nCWS6VU
             $this->assertSame($secrets[0], $secrets[$i]);
         }
     }
+
+    public function testCurve25519()
+    {
+        // utilizing test vector from https://tools.ietf.org/html/rfc7748#section-6.1
+
+        $alicePrivate = EC::loadFormat('Curve25519Private', pack('H*', '77076d0a7318a57d3c16c17251b26645df4c2f87ebc0992ab177fba51db92c2a'));
+        $bobPrivate = EC::loadFormat('Curve25519Private', pack('H*', '5dab087e624a8a4b79e17f8b83800ee66f3bb1292618b6fd1c2f8b27ff88e0eb'));
+
+        $alicePublic = $alicePrivate->getPublicKey();
+        $bobPublic = $bobPrivate->getPublicKey();
+
+        $this->assertSame(
+            '8520f0098930a754748b7ddcb43ef75a0dbf3a0d26381af4eba4a98eaa9b4e6a',
+            bin2hex($alicePublic->toString('Curve25519Public'))
+        );
+
+        $this->assertSame(
+            'de9edb7d7b7dc1b4d35b61c2ece435373f8343c85b78674dadfc7e146f882b4f',
+            bin2hex($bobPublic->toString('Curve25519Public'))
+        );
+
+        $expected = pack('H*', '4a5d9d5ba4ce2de1728e3bf480350f25e07e21c947d19e3376f09b3c1e161742');
+
+        $this->assertSame($expected, DH::computeSecret($alicePrivate, $bobPublic));
+        $this->assertSame($expected, DH::computeSecret($bobPrivate, $alicePublic));
+    }
 }