add OFB support

Author: terrafrost

composer.json

@@ -22,7 +22,7 @@
     },
     "require": {
         "php": ">=5.3.3",
-        "phpseclib/phpseclib": ">=2.0.11 <3.0.0"
+        "phpseclib/phpseclib": ">=2.0.36 <3.0.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.8.35|^5.7|^6.0|^9.4"

lib/mcrypt.php

@@ -226,7 +226,7 @@ function phpseclib_mcrypt_list_modes($lib_dir = '')
             'ecb',
             'ncfb',
             'nofb',
-            //'ofb',
+            'ofb',
             'stream'
         );
     }
@@ -273,6 +273,7 @@ function phpseclib_mcrypt_module_open($algorithm, $algorithm_directory, $mode, $
             'ecb' => Base::MODE_ECB,
             'cbc' => Base::MODE_CBC,
             'cfb' => Base::MODE_CFB8,
+            'ofb' => Base::MODE_OFB8,
             'ncfb'=> Base::MODE_CFB,
             'nofb'=> Base::MODE_OFB,
             'stream' => Base::MODE_STREAM
@@ -571,6 +572,8 @@ function phpseclib_mcrypt_enc_get_modes_name(Base $td)
             Base::MODE_CBC => 'CBC',
             Base::MODE_CFB => 'nCFB',
             Base::MODE_OFB => 'nOFB',
+            Base::MODE_CFB8 => 'CFB',
+            Base::MODE_OFB8 => 'OFB',
             Base::MODE_STREAM => 'STREAM'
         );
 
@@ -847,6 +850,7 @@ function phpseclib_mcrypt_module_is_block_algorithm_mode($mode, $lib_dir = '')
             case 'ctr':
             case 'ecb':
             case 'cfb':
+            case 'ofb':
             case 'ncfb':
             case 'nofb':
                 return true;

tests/MCryptCompatTest.php

@@ -962,6 +962,53 @@ public function test128ByteRC2Key()
         }
     }
 
+    public function testOFB()
+    {
+        $key = str_repeat('x', 32);
+        $iv = str_repeat('x', 32);
+        $plaintext = 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz';
+        $ciphertext = '3d49c7fab4f20c3cc2a54e5c0a22a4feceffb6fc758ee3800380614042c567731a35cf';
+
+        $td = phpseclib_mcrypt_module_open('rijndael-256', '', 'ofb', '');
+        phpseclib_mcrypt_generic_init($td, $key, $iv);
+        $mcrypt = bin2hex(phpseclib_mcrypt_generic($td, $plaintext));
+
+        $this->assertEquals(
+            $ciphertext,
+            $mcrypt
+        );
+
+        $td = phpseclib_mcrypt_module_open('rijndael-256', '', 'ofb', '');
+        phpseclib_mcrypt_generic_init($td, $key, $iv);
+        $mcrypt = bin2hex(phpseclib_mcrypt_generic($td, substr($plaintext, 0, -1)));
+        $mcrypt.= bin2hex(phpseclib_mcrypt_generic($td, substr($plaintext, -1)));
+
+        $this->assertEquals(
+            $ciphertext,
+            $mcrypt
+        );
+
+        $td = phpseclib_mcrypt_module_open('rijndael-256', '', 'ofb', '');
+        phpseclib_mcrypt_generic_init($td, $key, $iv);
+        $reference = phpseclib_mdecrypt_generic($td, pack('H*', $ciphertext));
+
+        $this->assertEquals(
+            $plaintext,
+            $reference
+        );
+
+        if (extension_loaded('mcrypt')) {
+            $td = mcrypt_module_open('rijndael-256', '', 'ofb', '');
+            mcrypt_generic_init($td, $key, $iv);
+            $mcrypt = bin2hex(mcrypt_generic($td, $plaintext));
+
+            $this->assertEquals(
+                $ciphertext,
+                $mcrypt
+            );
+        }
+    }
+
     public function mcryptModuleNameProvider()
     {
         return array(
@@ -997,6 +1044,7 @@ public function mcryptBlockModuleNameProvider()
             array('ctr', true),
             array('ecb', true),
             array('cfb', true),
+            array('ofb', true),
             array('ncfb', true),
             array('nofb', true),
             array('invalid-mode', false)