Use system default location for cafile when using php fopen.

Up to 5.5, PHP does not accept any certificates if cafile/capath
is not set. (From 5.6 it uses the system default CA budle, which is
going to be a better choice than anything we can guess.) So try
to guess the location of the system default CA bundle.

Won't work on windows, but that's a lost cause anyway because PHP
(pre-5.6) can't handle the windows CA file format.

Bug: T75203
Change-Id: I07736c150fe0783e09d297395ed25adf335edbd3

diff --git a/includes/HttpFunctions.php b/includes/HttpFunctions.php
index 1c79485..24c0dfc 100644 (file)
--- a/includes/HttpFunctions.php
+++ b/includes/HttpFunctions.php
@@ -865,6 +865,50 @@ class PhpHttpRequest extends MWHttpRequest {
                return 'tcp://' . $parsedUrl['host'] . ':' . $parsedUrl['port'];
        }
 
+       /**
+        * Returns an array with a 'capath' or 'cafile' key that is suitable to be merged into the 'ssl' sub-array of a
+        * stream context options array. Uses the 'caInfo' option of the class if it is provided, otherwise uses the system
+        * default CA bundle if PHP supports that, or searches a few standard locations.
+        * @return array
+        * @throws DomainException
+        */
+       protected function getCertOptions() {
+               $certOptions = array();
+               $certLocations = array();
+               if ( $this->caInfo ) {
+                       $certLocations = array( 'manual' => $this->caInfo );
+               } elseif ( version_compare( PHP_VERSION, '5.6.0', '<' ) ) {
+                       // Default locations, based on
+                       // https://www.happyassassin.net/2015/01/12/a-note-about-ssltls-trusted-certificate-stores-and-platforms/
+                       // PHP 5.5 and older doesn't have any defaults, so we try to guess ourselves. PHP 5.6+ gets the CA location
+                       // from OpenSSL as long as it is not set manually, so we should leave capath/cafile empty there.
+                       $certLocations = array_filter( array(
+                               getenv( 'SSL_CERT_DIR' ),
+                               getenv( 'SSL_CERT_PATH' ),
+                               '/etc/pki/tls/certs/ca-bundle.crt', # Fedora et al
+                               '/etc/ssl/certs',  # Debian et al
+                               '/etc/pki/tls/certs/ca-bundle.trust.crt',
+                               '/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem',
+                               '/System/Library/OpenSSL', # OSX
+                       ) );
+               }
+
+               foreach( $certLocations as $key => $cert ) {
+                       if ( is_dir( $cert ) ) {
+                               $certOptions['capath'] = $cert;
+                               break;
+                       } elseif ( is_file( $cert ) ) {
+                               $certOptions['cafile'] = $cert;
+                               break;
+                       } elseif ( $key === 'manual' ) {
+                               // fail more loudly if a cert path was manually configured and it is not valid
+                               throw new DomainException( "Invalid CA info passed: $cert" );
+                       }
+               }
+
+               return $certOptions;
+       }
+
        public function execute() {
 
                parent::execute();
@@ -926,13 +970,7 @@ class PhpHttpRequest extends MWHttpRequest {
                        }
                }
 
-               if ( is_dir( $this->caInfo ) ) {
-                       $options['ssl']['capath'] = $this->caInfo;
-               } elseif ( is_file( $this->caInfo ) ) {
-                       $options['ssl']['cafile'] = $this->caInfo;
-               } elseif ( $this->caInfo ) {
-                       throw new MWException( "Invalid CA info passed: {$this->caInfo}" );
-               }
+               $options['ssl'] += $this->getCertOptions();
 
                $context = stream_context_create( $options );