Internationalized domain name (IDN) support

composer.json

@@ -28,11 +28,13 @@
     },
     "require-dev": {
         "ext-curl": "*",
+        "ext-intl": "*",
         "phpunit/phpunit": "^4.8.35 || ^5.7 || ^6.4 || ^7.0",
         "psr/log": "^1.1"
     },
     "suggest": {
-        "psr/log": "Required for using the Log middleware"
+        "psr/log": "Required for using the Log middleware",
+        "ext-intl": "Required for Internationalized Domain Name (IDN) support"
     },
     "config": {
         "sort-packages": true

docs/request-options.rst

@@ -553,6 +553,31 @@ http_errors
     default when creating a handler with ``GuzzleHttp\default_handler``.
 
 
+idn_conversion
+---
+
+:Summary: Set to ``false`` to disable Internationalized Domain Name (IDN) to
+    ASCII conversion.
+:Types:
+    - bool
+    - int
+:Default: ``true`` if ``intl`` extension is available, ``false`` otherwise
+:Constant: ``GuzzleHttp\RequestOptions::IDN_CONVERSION``
+
+.. code-block:: php
+
+    $client->request('GET', 'https://яндекс.рф');
+    // яндекс.рф is translated to  internally
+
+    $res = $client->request('GET', 'https://яндекс.рф', ['idn_conversion' => false]);
+    // The domain part (яндекс.рф) stays unmodified
+
+Also a combination of IDNA_* constants (except IDNA_ERROR_*) also can be used
+for precise control of the IDN support (see ``$options`` parameter in
+`idn_to_ascii() <https://www.php.net/manual/en/function.idn-to-ascii.php>`_
+documentation for more details).
+
+
 json
 ----
 

src/Client.php

@@ -2,6 +2,7 @@
 namespace GuzzleHttp;
 
 use GuzzleHttp\Cookie\CookieJar;
+use GuzzleHttp\Exception\InvalidArgumentException;
 use GuzzleHttp\Promise;
 use GuzzleHttp\Psr7;
 use Psr\Http\Message\UriInterface;
@@ -147,6 +148,38 @@ private function buildUri($uri, array $config)
             $uri = Psr7\UriResolver::resolve(Psr7\uri_for($config['base_uri']), $uri);
         }
 
+        if ($uri->getHost() && isset($config['idn_conversion']) && ($config['idn_conversion'] !== false)) {
+            $idnOptions = ($config['idn_conversion'] === true) ? IDNA_DEFAULT : $config['idn_conversion'];
+
+            $asciiHost = idn_to_ascii($uri->getHost(), $idnOptions, INTL_IDNA_VARIANT_UTS46, $info);
+            if ($asciiHost === false) {
+                $errorBitSet = isset($info['errors']) ? $info['errors'] : 0;
+
+                $errorConstants = array_filter(array_keys(get_defined_constants()), function ($name) {
+                    return substr($name, 0, 11) === 'IDNA_ERROR_';
+                });
+
+                $errors = [];
+                foreach ($errorConstants as $errorConstant) {
+                    if ($errorBitSet & constant($errorConstant)) {
+                        $errors[] = $errorConstant;
+                    }
+                }
+
+                $errorMessage = 'IDN conversion failed';
+                if ($errors) {
+                    $errorMessage .= ' (errors: ' . implode(', ', $errors) . ')';
+                }
+
+                throw new InvalidArgumentException($errorMessage);
+            } else {
+                if ($uri->getHost() !== $asciiHost) {
+                    // Replace URI only if the ASCII version is different
+                    $uri = $uri->withHost($asciiHost);
+                }
+            }
+        }
+
         return $uri->getScheme() === '' && $uri->getHost() !== '' ? $uri->withScheme('http') : $uri;
     }
 
@@ -165,6 +198,9 @@ private function configureDefaults(array $config)
             'cookies'         => false
         ];
 
+        // idn_to_ascii() is a part of ext-intl and might be not available
+        $defaults['idn_conversion'] = function_exists('idn_to_ascii');
+
         // Use the standard Linux HTTP_PROXY and HTTPS_PROXY if set.
 
         // We can only trust the HTTP_PROXY environment variable in a CLI

src/RequestOptions.php

@@ -132,6 +132,14 @@ final class RequestOptions
      */
     const HTTP_ERRORS = 'http_errors';
 
+    /**
+     * idn: (bool|int, default=true) Set to false to disable exceptions
+     * when a non- successful HTTP response is received. By default,
+     * exceptions will be thrown for 4xx and 5xx responses. This option only
+     * works if your handler has the `httpErrors` middleware.
+     */
+    const IDN_CONVERSION = 'idn_conversion';
+
     /**
      * json: (mixed) Adds JSON data to a request. The provided value is JSON
      * encoded and a Content-Type header of application/json will be added to

tests/ClientTest.php

@@ -10,8 +10,8 @@
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\Psr7\Response;
 use GuzzleHttp\Psr7\Uri;
-use Psr\Http\Message\ResponseInterface;
 use PHPUnit\Framework\TestCase;
+use Psr\Http\Message\ResponseInterface;
 
 class ClientTest extends TestCase
 {
@@ -674,4 +674,57 @@ public function testHandlerIsCallable()
     {
         new Client(['handler' => 'not_cllable']);
     }
+
+    /**
+     * Unfortunately, it's hard to test the opposite.
+     *
+     * @requires extension intl
+     */
+    public function testIdnSupportIsEnabledByDefaultIfIntlExtensionIsAvailable()
+    {
+        $mockHandler = new MockHandler([new Response()]);
+        $client = new Client(['handler' => $mockHandler]);
+
+        $config = $client->getConfig();
+
+        $this->assertTrue($config['idn_conversion']);
+    }
+
+    public function testIdnIsTranslatedToAsciiWhenSupportIsEnabled()
+    {
+        $mockHandler = new MockHandler([new Response()]);
+        $client = new Client(['handler' => $mockHandler]);
+
+        $client->request('GET', 'https://яндекс.рф/images', ['idn_conversion' => true]);
+
+        $request = $mockHandler->getLastRequest();
+
+        $this->assertSame('https://xn--d1acpjx3f.xn--p1ai/images', (string) $request->getUri());
+        $this->assertSame('xn--d1acpjx3f.xn--p1ai', (string) $request->getHeaderLine('Host'));
+    }
+
+    public function testIdnStaysTheSameWhenSupportIsDisabled()
+    {
+        $mockHandler = new MockHandler([new Response()]);
+        $client = new Client(['handler' => $mockHandler]);
+
+        $client->request('GET', 'https://яндекс.рф/images', ['idn_conversion' => false]);
+
+        $request = $mockHandler->getLastRequest();
+
+        $this->assertSame('https://яндекс.рф/images', (string) $request->getUri());
+        $this->assertSame('яндекс.рф', (string) $request->getHeaderLine('Host'));
+    }
+
+    /**
+     * @expectedException \GuzzleHttp\Exception\InvalidArgumentException
+     * @expectedExceptionMessage IDN conversion failed (errors: IDNA_ERROR_LEADING_HYPHEN)
+     */
+    public function testExceptionOnInvalidIdn()
+    {
+        $mockHandler = new MockHandler([new Response()]);
+        $client = new Client(['handler' => $mockHandler]);
+
+        $client->request('GET', 'https://-яндекс.рф/images', ['idn_conversion' => true]);
+    }
 }

tests/bootstrap.php

@@ -1,4 +1,9 @@
 <?php
+
+namespace {
+    setlocale(LC_ALL, 'C');
+}
+
 namespace GuzzleHttp\Test {
     require __DIR__ . '/../vendor/autoload.php';
     require __DIR__ . '/Server.php';