From 2c1994805b2c53df12ae244736aba6c568b7ed83 Mon Sep 17 00:00:00 2001
From: terrafrost <terrafrost@php.net>
Date: Thu, 29 Nov 2018 10:05:28 -0600
Subject: [PATCH] ECDSA: make it so hash can't be changed for Ed25519 / Ed448

---
 phpseclib/Crypt/Common/AsymmetricKey.php | 16 ++++++++
 phpseclib/Crypt/ECDSA.php                | 50 +++++++++++++++++++++---
 2 files changed, 61 insertions(+), 5 deletions(-)

diff --git a/phpseclib/Crypt/Common/AsymmetricKey.php b/phpseclib/Crypt/Common/AsymmetricKey.php
index fa90c129..a95f7e80 100644
--- a/phpseclib/Crypt/Common/AsymmetricKey.php
+++ b/phpseclib/Crypt/Common/AsymmetricKey.php
@@ -151,6 +151,14 @@ abstract class AsymmetricKey
      */
     private $hmac;
 
+    /**
+     * Hash manually set?
+     *
+     * @var bool
+     * @access private
+     */
+    protected $hashManuallySet = false;
+
     /**
      * Available Engines
      *
@@ -284,6 +292,12 @@ abstract class AsymmetricKey
      */
     protected function load($key, $type)
     {
+        if ($key instanceof self) {
+            $this->hmac = $key->hmac;
+
+            return;
+        }
+
         $components = false;
         if ($type === false) {
             foreach (self::$plugins[static::ALGORITHM]['Keys'] as $format) {
@@ -594,6 +608,8 @@ abstract class AsymmetricKey
     {
         $this->hash = new Hash($hash);
         $this->hmac = new Hash($hash);
+
+        $this->hashManuallySet = true;
     }
 
     /**
diff --git a/phpseclib/Crypt/ECDSA.php b/phpseclib/Crypt/ECDSA.php
index 4af8c4fd..7bd27347 100644
--- a/phpseclib/Crypt/ECDSA.php
+++ b/phpseclib/Crypt/ECDSA.php
@@ -37,6 +37,7 @@ use phpseclib\File\ASN1;
 use phpseclib\File\ASN1\Maps\ECParameters;
 use phpseclib\Crypt\ECDSA\BaseCurves\TwistedEdwards as TwistedEdwardsCurve;
 use phpseclib\Crypt\ECDSA\Curves\Ed25519;
+use phpseclib\Crypt\ECDSA\Curves\Ed448;
 use phpseclib\Crypt\ECDSA\Keys\PKCS1;
 use phpseclib\Crypt\ECDSA\Keys\PKCS8;
 use phpseclib\Crypt\ECDSA\Signature\ASN1 as ASN1Signature;
@@ -198,20 +199,28 @@ class ECDSA extends AsymmetricKey
             $this->QA = $key->QA;
             $this->curve = $key->curve;
             $this->parametersFormat = $key->parametersFormat;
+            $this->hash = $key->hash;
+
+            parent::load($key, false);
 
             return true;
         }
 
         $components = parent::load($key, $type);
         if ($components === false) {
-            $this->format = null;
-            $this->dA = null;
-            $this->QA = null;
-            $this->curve = null;
-
+            $this->clearKey();
             return false;
         }
 
+        if ($components['curve'] instanceof Ed25519 && $this->hashManuallySet && $this->hash->getHash() != 'sha512') {
+            $this->clearKey();
+            throw new \RuntimeException('Ed25519 only supports sha512 as a hash');
+        }
+        if ($components['curve'] instanceof Ed448 && $this->hashManuallySet && $this->hash->getHash() != 'shake256-912') {
+            $this->clearKey();
+            throw new \RuntimeException('Ed448 only supports shake256 with a length of 114 bytes');
+        }
+
         $this->curve = $components['curve'];
         $this->QA = $components['QA'];
         $this->dA = isset($components['dA']) ? $components['dA'] : null;
@@ -219,6 +228,19 @@ class ECDSA extends AsymmetricKey
         return true;
     }
 
+    /**
+     * Removes a key
+     *
+     * @access private
+     */
+    private function clearKey()
+    {
+        $this->format = null;
+        $this->dA = null;
+        $this->QA = null;
+        $this->curve = null;
+    }
+
     /**
      * Returns the curve
      *
@@ -439,6 +461,24 @@ class ECDSA extends AsymmetricKey
         $this->context = $context;
     }
 
+    /**
+     * Determines which hashing function should be used
+     *
+     * @access public
+     * @param string $hash
+     */
+    public function setHash($hash)
+    {
+        if ($this->curve instanceof Ed25519 && $this->hash != 'sha512') {
+            throw new \RuntimeException('Ed25519 only supports sha512 as a hash');
+        }
+        if ($this->curve instanceof Ed448 && $this->hash != 'shake256-912') {
+            throw new \RuntimeException('Ed448 only supports shake256 with a length of 114 bytes');
+        }
+
+        parent::setHash($hash);
+    }
+
     /**
      * Create a signature
      *