diff --git a/composer.lock b/composer.lock
index 095320d6a..a51d97be1 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,20 +4,20 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "content-hash": "809b291b5f9da41a8bdd414a058e3f07",
+    "content-hash": "88357fd4222a8102552a0d3345696e2e",
     "packages": [
         {
             "name": "composer/ca-bundle",
-            "version": "1.0.8",
+            "version": "1.1.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/composer/ca-bundle.git",
-                "reference": "9dd73a03951357922d8aee6cc084500de93e2343"
+                "reference": "943b2c4fcad1ef178d16a713c2468bf7e579c288"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/composer/ca-bundle/zipball/9dd73a03951357922d8aee6cc084500de93e2343",
-                "reference": "9dd73a03951357922d8aee6cc084500de93e2343",
+                "url": "https://api.github.com/repos/composer/ca-bundle/zipball/943b2c4fcad1ef178d16a713c2468bf7e579c288",
+                "reference": "943b2c4fcad1ef178d16a713c2468bf7e579c288",
                 "shasum": ""
             },
             "require": {
@@ -26,12 +26,9 @@
                 "php": "^5.3.2 || ^7.0"
             },
             "require-dev": {
-                "phpunit/phpunit": "^4.5",
+                "phpunit/phpunit": "^4.8.35",
                 "psr/log": "^1.0",
-                "symfony/process": "^2.5 || ^3.0"
-            },
-            "suggest": {
-                "symfony/process": "This is necessary to reliably check whether openssl_x509_parse is vulnerable on older php versions, but can be ignored on PHP 5.5.6+"
+                "symfony/process": "^2.5 || ^3.0 || ^4.0"
             },
             "type": "library",
             "extra": {
@@ -63,7 +60,7 @@
                 "ssl",
                 "tls"
             ],
-            "time": "2017-09-11T07:24:36+00:00"
+            "time": "2017-11-29T09:37:33+00:00"
         },
         {
             "name": "composer/semver",
diff --git a/src/Composer/Util/RemoteFilesystem.php b/src/Composer/Util/RemoteFilesystem.php
index b83639a82..d61fb15f4 100644
--- a/src/Composer/Util/RemoteFilesystem.php
+++ b/src/Composer/Util/RemoteFilesystem.php
@@ -904,17 +904,7 @@ class RemoteFilesystem
         if (!isset($defaults['ssl']['cafile']) && !isset($defaults['ssl']['capath'])) {
             $result = CaBundle::getSystemCaRootBundlePath($caBundleLogger);
 
-            if (preg_match('{^phar://}', $result)) {
-                $hash = hash_file('sha256', $result);
-                $targetPath = rtrim(sys_get_temp_dir(), '\\/') . '/composer-cacert-' . $hash . '.pem';
-
-                if (!file_exists($targetPath) || $hash !== hash_file('sha256', $targetPath)) {
-                    $this->streamCopy($result, $targetPath);
-                    chmod($targetPath, 0666);
-                }
-
-                $defaults['ssl']['cafile'] = $targetPath;
-            } elseif (is_dir($result)) {
+            if (is_dir($result)) {
                 $defaults['ssl']['capath'] = $result;
             } else {
                 $defaults['ssl']['cafile'] = $result;
@@ -939,24 +929,6 @@ class RemoteFilesystem
         return $defaults;
     }
 
-    /**
-     * Uses stream_copy_to_stream instead of copy to work around https://bugs.php.net/bug.php?id=64634
-     *
-     * @param string $source
-     * @param string $target
-     */
-    private function streamCopy($source, $target)
-    {
-        $source = fopen($source, 'r');
-        $target = fopen($target, 'w+');
-
-        stream_copy_to_stream($source, $target);
-        fclose($source);
-        fclose($target);
-
-        unset($source, $target);
-    }
-
     /**
      * Fetch certificate common name and fingerprint for validation of SAN.
      *