Support RSA_SHA256_MGF1 (#269)

* add support for RSA PSS (http://www.w3.org/2007/05/xmldsig-more#sha256-rsa-MGF1)
* use phpseclib for `http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p` as well
* return 1 if successful and 0 otherwise
* use phpseclib for encrypting http://www.w3.org/2009/xmlenc11#rsa-oaep
---------

Co-authored-by: Julius Türich <info@joonlabs.com>
Co-authored-by: joonlabs <52662462+joonlabs@users.noreply.github.com>

Author: AlexanderWillner

src/XMLSecurityKey.php

@@ -3,6 +3,8 @@
 
 use DOMElement;
 use Exception;
+use phpseclib3\Crypt\PublicKeyLoader;
+use phpseclib3\Crypt\RSA;
 
 /**
  * xmlseclibs.php
@@ -62,6 +64,7 @@ class XMLSecurityKey
     const RSA_SHA384 = 'http://www.w3.org/2001/04/xmldsig-more#rsa-sha384';
     const RSA_SHA512 = 'http://www.w3.org/2001/04/xmldsig-more#rsa-sha512';
     const HMAC_SHA1 = 'http://www.w3.org/2000/09/xmldsig#hmac-sha1';
+    const RSA_SHA256_MGF1 = 'http://www.w3.org/2007/05/xmldsig-more#sha256-rsa-MGF1';
     const AUTHTAG_LENGTH = 16;
 
     /** @var array */
@@ -183,10 +186,10 @@ public function __construct($type, $params=null)
                 }
                 throw new Exception('Certificate "type" (private/public) must be passed via parameters');
             case (self::RSA_OAEP_MGF1P):
-                $this->cryptParams['library'] = 'openssl';
-                $this->cryptParams['padding'] = OPENSSL_PKCS1_OAEP_PADDING;
+                $this->cryptParams['library'] = 'phpseclib';
+                $this->cryptParams['padding'] = RSA::ENCRYPTION_OAEP;
                 $this->cryptParams['method'] = 'http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p';
-                $this->cryptParams['hash'] = null;
+                $this->cryptParams['digest'] = 'sha1';
                 if (is_array($params) && ! empty($params['type'])) {
                     if ($params['type'] == 'public' || $params['type'] == 'private') {
                         $this->cryptParams['type'] = $params['type'];
@@ -195,10 +198,10 @@ public function __construct($type, $params=null)
                 }
                 throw new Exception('Certificate "type" (private/public) must be passed via parameters');
             case (self::RSA_OAEP):
-                $this->cryptParams['library'] = 'openssl';
-                $this->cryptParams['padding'] = OPENSSL_PKCS1_OAEP_PADDING;
+                $this->cryptParams['library'] = 'phpseclib';
+                $this->cryptParams['padding'] = RSA::ENCRYPTION_OAEP;
                 $this->cryptParams['method'] = 'http://www.w3.org/2009/xmlenc11#rsa-oaep';
-                $this->cryptParams['hash'] = 'http://www.w3.org/2009/xmlenc11#mgf1sha1';
+                $this->cryptParams['digest'] = 'sha256';
                 if (is_array($params) && ! empty($params['type'])) {
                     if ($params['type'] == 'public' || $params['type'] == 'private') {
                         $this->cryptParams['type'] = $params['type'];
@@ -257,6 +260,18 @@ public function __construct($type, $params=null)
                 $this->cryptParams['library'] = $type;
                 $this->cryptParams['method'] = 'http://www.w3.org/2000/09/xmldsig#hmac-sha1';
                 break;
+            case (self::RSA_SHA256_MGF1):
+                $this->cryptParams['library'] = 'phpseclib';
+                $this->cryptParams['method'] = 'http://www.w3.org/2007/05/xmldsig-more#sha256-rsa-MGF1';
+                $this->cryptParams['padding'] = RSA::SIGNATURE_PSS;
+                $this->cryptParams['digest'] = 'SHA256';
+                if (is_array($params) && ! empty($params['type'])) {
+                    if ($params['type'] == 'public' || $params['type'] == 'private') {
+                        $this->cryptParams['type'] = $params['type'];
+                        break;
+                    }
+                }
+                throw new Exception('Certificate "type" (private/public) must be passed via parameters');
             default:
                 throw new Exception('Invalid Key Type');
         }
@@ -291,9 +306,9 @@ public function generateSessionKey()
             throw new Exception('Unknown key size for type "' . $this->type . '".');
         }
         $keysize = $this->cryptParams['keysize'];
-        
+
         $key = openssl_random_pseudo_bytes($keysize);
-        
+
         if ($this->type === self::TRIPLEDES_CBC) {
             /* Make sure that the generated key has the proper parity bits set.
              * Mcrypt doesn't care about the parity bits, but others may care.
@@ -308,7 +323,7 @@ public function generateSessionKey()
                 $key[$i] = chr($byte);
             }
         }
-        
+
         $this->key = $key;
         return $key;
     }
@@ -372,17 +387,17 @@ public function loadKey($key, $isFile=false, $isCert = false)
         if ($this->cryptParams['library'] == 'openssl') {
             switch ($this->cryptParams['type']) {
                 case 'public':
-	                if ($isCert) {
-	                    /* Load the thumbprint if this is an X509 certificate. */
-	                    $this->X509Thumbprint = self::getRawThumbprint($this->key);
-	                }
-	                $this->key = openssl_get_publickey($this->key);
-	                if (! $this->key) {
-	                    throw new Exception('Unable to extract public key');
-	                }
-	                break;
-
-	            case 'private':
+                    if ($isCert) {
+                        /* Load the thumbprint if this is an X509 certificate. */
+                        $this->X509Thumbprint = self::getRawThumbprint($this->key);
+                    }
+                    $this->key = openssl_get_publickey($this->key);
+                    if (! $this->key) {
+                        throw new Exception('Unable to extract public key');
+                    }
+                    break;
+
+                case 'private':
                     $this->key = openssl_get_privatekey($this->key, $this->passphrase);
                     break;
 
@@ -450,7 +465,7 @@ private function encryptSymmetric($data)
             $data = $this->padISO10126($data, $this->cryptParams['blocksize']);
             $encrypted = openssl_encrypt($data, $this->cryptParams['cipher'], $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $this->iv);
         }
-        
+
         if (false === $encrypted) {
             throw new Exception('Failure encrypting Data (openssl symmetric) - ' . openssl_error_string());
         }
@@ -481,7 +496,7 @@ private function decryptSymmetric($data)
         } else {
             $decrypted = openssl_decrypt($data, $this->cryptParams['cipher'], $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $this->iv);
         }
-        
+
         if (false === $decrypted) {
             throw new Exception('Failure decrypting Data (openssl symmetric) - ' . openssl_error_string());
         }
@@ -629,6 +644,14 @@ public function decryptData($data)
                 case 'private':
                     return $this->decryptPrivate($data);
             }
+        } else if($this->cryptParams['library'] === 'phpseclib') {
+            $private = PublicKeyLoader::load($this->key);
+            $result = $private
+                ->withPadding($this->cryptParams['padding'])
+                ->withHash($this->cryptParams['digest'])
+                ->withMGFHash($this->cryptParams['digest'])
+                ->decrypt($data);
+            return $result;
         }
     }
 
@@ -643,6 +666,13 @@ public function signData($data)
         switch ($this->cryptParams['library']) {
             case 'openssl':
                 return $this->signOpenSSL($data);
+            case 'phpseclib':
+                $private = PublicKeyLoader::load($this->key);
+                return $private
+                    ->withPadding($this->cryptParams['padding'])
+                    ->withHash($this->cryptParams['digest'])
+                    ->withMGFHash($this->cryptParams['digest'])
+                    ->sign($data);
             case (self::HMAC_SHA1):
                 return hash_hmac("sha1", $data, $this->key, true);
         }
@@ -669,6 +699,14 @@ public function verifySignature($data, $signature)
         switch ($this->cryptParams['library']) {
             case 'openssl':
                 return $this->verifyOpenSSL($data, $signature);
+            case 'phpseclib':
+                $public = PublicKeyLoader::load($this->key);
+                $result = $public
+                    ->withPadding($this->cryptParams['padding'])
+                    ->withHash($this->cryptParams['digest'])
+                    ->withMGFHash($this->cryptParams['digest'])
+                    ->verify($data, $signature);
+                return $result === true ? 1 : 0;
             case (self::HMAC_SHA1):
                 $expectedSignature = hash_hmac("sha1", $data, $this->key, true);
                 return strcmp($signature, $expectedSignature) == 0;