diff --git a/phpseclib/Crypt/RSA.php b/phpseclib/Crypt/RSA.php
index 33e86c6d..300dd7f9 100644
--- a/phpseclib/Crypt/RSA.php
+++ b/phpseclib/Crypt/RSA.php
@@ -1031,22 +1031,22 @@ class RSA
 
 
     /**
-     *  __toString() magic method
+     * __toString() magic method
      *
      * @access public
      */
     function __toString()
     {
         $key = $this->getPrivateKey($this->privateKeyFormat);
-        if ($key !== false) {
+        if (is_string($key)) {
             return $key;
         }
         $key = $this->_getPrivatePublicKey($this->publicKeyFormat);
-        return $key !== false ? $key : '';
+        return is_string($key) ? $key : '';
     }
 
     /**
-     *  __clone() magic method
+     * __clone() magic method
      *
      * @access public
      */
diff --git a/phpseclib/Crypt/RSA/Raw.php b/phpseclib/Crypt/RSA/Raw.php
index 47ebc3a0..d3992521 100644
--- a/phpseclib/Crypt/RSA/Raw.php
+++ b/phpseclib/Crypt/RSA/Raw.php
@@ -48,32 +48,42 @@ class Raw
         if (!is_array($key)) {
             return false;
         }
+        if (isset($key['isPublicKey']) && isset($key['modulus'])) {
+            if (isset($key['privateExponent']) || isset($key['publicExponent'])) {
+                if (!isset($key['primes'])) {
+                    return $key;
+                }
+                if (isset($key['exponents']) && isset($key['coefficients']) && isset($key['publicExponent']) && isset($key['privateExponent'])) {
+                    return $key;
+                }
+            }
+        }
         $components = array('isPublicKey' => true);
         switch (true) {
             case isset($key['e']):
-                $components['publicExponent'] = $key['e']->copy();
+                $components['publicExponent'] = $key['e'];
                 break;
             case isset($key['exponent']):
-                $components['publicExponent'] = $key['exponent']->copy();
+                $components['publicExponent'] = $key['exponent'];
                 break;
             case isset($key['publicExponent']):
-                $components['publicExponent'] = $key['publicExponent']->copy();
+                $components['publicExponent'] = $key['publicExponent'];
                 break;
             case isset($key[0]):
-                $components['publicExponent'] = $key[0]->copy();
+                $components['publicExponent'] = $key[0];
         }
         switch (true) {
             case isset($key['n']):
-                $components['modulus'] = $key['n']->copy();
+                $components['modulus'] = $key['n'];
                 break;
             case isset($key['modulo']):
-                $components['modulus'] = $key['modulo']->copy();
+                $components['modulus'] = $key['modulo'];
                 break;
             case isset($key['modulus']):
-                $components['modulus'] = $key['modulus']->copy();
+                $components['modulus'] = $key['modulus'];
                 break;
             case isset($key[1]):
-                $components['modulus'] = $key[1]->copy();
+                $components['modulus'] = $key[1];
         }
         return isset($components['modulus']) && isset($components['publicExponent']) ? $components : false;
     }
diff --git a/tests/Unit/Crypt/RSA/LoadKeyTest.php b/tests/Unit/Crypt/RSA/LoadKeyTest.php
index ee28863d..ec858630 100644
--- a/tests/Unit/Crypt/RSA/LoadKeyTest.php
+++ b/tests/Unit/Crypt/RSA/LoadKeyTest.php
@@ -7,6 +7,7 @@
 
 use phpseclib\Crypt\RSA;
 use phpseclib\Crypt\RSA\PKCS1;
+use phpseclib\Math\BigInteger;
 
 class Unit_Crypt_RSA_LoadKeyTest extends PhpseclibTestCase
 {
@@ -361,4 +362,49 @@ Private-MAC: 03e2cb74e1d67652fbad063d2ed0478f31bdf256
 
         $this->assertSame($key, $key2);
     }
+
+    public function testRawKey()
+    {
+        $rsa = new RSA();
+
+        $key = array(
+            'e' => BigInteger('10001', 16),
+            'n' => BigInteger('aa18aba43b50deef38598faf87d2ab634e4571c130a9bca7b878267414faab8b471bd8965f5c9fc3' .
+                              '818485eaf529c26246f3055064a8de19c8c338be5496cbaeb059dc0b358143b44a35449eb2641131' .
+                              '21a455bd7fde3fac919e94b56fb9bb4f651cdb23ead439d6cd523eb08191e75b35fd13a7419b3090' .
+                              'f24787bd4f4e1967', 16)
+        );
+        $this->assertTrue($rsa->load($key));
+        $rsa->setPublicKeyFormat('raw');
+        $this->assertEmpty("$rsa");
+    }
+
+    public function testRawComment()
+    {
+        $key = 'PuTTY-User-Key-File-2: ssh-rsa
+Encryption: aes256-cbc
+Comment: phpseclib-generated-key
+Public-Lines: 4
+AAAAB3NzaC1yc2EAAAADAQABAAAAgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4
+eCZ0FPqri0cb2JZfXJ/DgYSF6vUpwmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RK
+NUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ51s1SPrCBkedbNf0Tp0GbMJDy
+R4e9T04ZZw==
+Private-Lines: 8
+llx04QMegql0/nE5RvcJSrGrodxt6ytuv/JX2caeZBUyQwQc2WBNYagLHyHPM9jI
+9OUWz59FLhjFXZMDNMoUXxVmjwQpOAaVPYNxxFM9AF6/NXFji64K7huD9n4A+kLn
+sHwMLWPR5a/tZA0r05DZNz9ULA3mQu7Hz4EQ8ifu3uTPJuTmL51x6RmudYKysb20
+fM8VzC3ukvzzRh0pujUVTr/yQdmciASVFnZlt4xQy+ZEOVUAOfwjd//AFfXTvk6x
+7A45rNlU/uicHwLgoY1APvRHCFxw7F+uVW5L4mSX7NNzqBKkZ+1qpQTAfQvIfEIb
+444+CXsgIyOpqt6VxJH2u6elAtE1wau3YaFR8Alm8m97rFYzRi3oDP5NZYkTCWSV
+EOpSeghXSs7IilJu8I6/sB1w5dakdeBSFkIynrlFXkO0uUw+QJJWjxY8SypzgIuP
+DzduF6XsQrCyo6dnIpGQCQ==
+Private-MAC: 35134b7434bf828b21404099861d455e660e8740';
+        $raw = PuTTY::load($key, 'password');
+        $this->assertArrayHasKey('comment', $raw);
+        $this->assertEquals($raw['comment'], 'phpseclib-generated-key');
+
+        $rsa = new RSA();
+        $rsa->load($raw);
+        $this->assertGreaterThanOrEqual(1, strlen("$rsa"));
+    }
 }