RSA: make it so you can't sign w/ public key, decrypt w/ private

phpseclib/Crypt/RSA.php

@@ -52,6 +52,8 @@ use phpseclib\Common\Functions\Strings;
 use phpseclib\File\ASN1\Maps\DigestInfo;
 use phpseclib\Crypt\Common\AsymmetricKey;
 use phpseclib\Exception\UnsupportedAlgorithmException;
+use phpseclib\Exception\UnsupportedOperationException;
+use phpseclib\Exception\NoKeyLoadedException;
 
 /**
  * Pure-PHP PKCS#1 compliant implementation of RSA.
@@ -201,7 +203,6 @@ class RSA extends AsymmetricKey
      */
     private $sLen;
 
-
     /**
      * Comment
      *
@@ -243,6 +244,14 @@ class RSA extends AsymmetricKey
      */
     private static $defaultExponent = 65537;
 
+    /**
+     * Is the loaded key a public key?
+     *
+     * @var bool
+     * @access private
+     */
+    private $isPublic = false;
+
     /**
      * Smallest Prime
      *
@@ -450,6 +459,7 @@ class RSA extends AsymmetricKey
         $publickey->k = $bits >> 3;
         $publickey->exponent = $e;
         $publickey->publicExponent = $e;
+        $publickey->isPublic = true;
 
         return compact('privatekey', 'publickey');
     }
@@ -475,6 +485,7 @@ class RSA extends AsymmetricKey
             $this->sLen = $key->sLen;
             $this->mgfHLen = $key->mgfHLen;
             $this->password = $key->password;
+            $this->isPublic = $key->isPublic;
 
             if (is_object($key->hash)) {
                 $this->hash = new Hash($key->hash->getHash());
@@ -524,6 +535,7 @@ class RSA extends AsymmetricKey
             return false;
         }
 
+        $this->isPublic = false;
         $this->modulus = $components['modulus'];
         $this->k = $this->modulus->getLengthInBytes();
         $this->exponent = isset($components['privateExponent']) ? $components['privateExponent'] : $components['publicExponent'];
@@ -669,6 +681,7 @@ class RSA extends AsymmetricKey
         }
 
         if ($key === false && !empty($this->modulus)) {
+            $this->isPublic = true;
             $this->publicExponent = $this->exponent;
             return true;
         }
@@ -681,6 +694,7 @@ class RSA extends AsymmetricKey
         if (empty($this->modulus) || !$this->modulus->equals($components['modulus'])) {
             $this->modulus = $components['modulus'];
             $this->exponent = $this->publicExponent = $components['publicExponent'];
+            $this->isPublic = true;
             return true;
         }
 
@@ -689,6 +703,18 @@ class RSA extends AsymmetricKey
         return true;
     }
 
+    /**
+     * Does the key self-identify as being a public key or not?
+     *
+     * @see self::isPublicKey()
+     * @access public
+     * @return bool
+     */
+    public function isPublicKey()
+    {
+        return $this->isPublic();
+    }
+
     /**
      * Defines the private key
      *
@@ -1729,6 +1755,14 @@ class RSA extends AsymmetricKey
      */
     public function encrypt($plaintext, $padding = self::PADDING_OAEP)
     {
+        if (empty($this->modulus) || empty($this->exponent)) {
+            throw new NoKeyLoadedException('No key has been loaded');
+        }
+
+        if (!$this->isPublic) {
+            throw new UnsupportedOperationException('phpseclib does not allow the use of private keys to encrypt data');
+        }
+
         switch ($padding) {
             case self::PADDING_NONE:
                 return $this->raw_encrypt($plaintext);
@@ -1752,6 +1786,14 @@ class RSA extends AsymmetricKey
      */
     public function decrypt($ciphertext, $padding = self::PADDING_OAEP)
     {
+        if (empty($this->modulus) || empty($this->exponent)) {
+            throw new NoKeyLoadedException('No key has been loaded');
+        }
+
+        if ($this->isPublic) {
+            throw new UnsupportedOperationException('phpseclib does not allow the use of public keys to decrypt data');
+        }
+
         switch ($padding) {
             case self::PADDING_NONE:
                 return $this->raw_encrypt($ciphertext);
@@ -1775,7 +1817,11 @@ class RSA extends AsymmetricKey
     public function sign($message, $padding = self::PADDING_PSS)
     {
         if (empty($this->modulus) || empty($this->exponent)) {
-            return false;
+            throw new NoKeyLoadedException('No key has been loaded');
+        }
+
+        if ($this->isPublic) {
+            throw new UnsupportedOperationException('phpseclib does not allow the use of public keys to sign data');
         }
 
         switch ($padding) {
@@ -1801,7 +1847,11 @@ class RSA extends AsymmetricKey
     public function verify($message, $signature, $padding = self::PADDING_PSS)
     {
         if (empty($this->modulus) || empty($this->exponent)) {
-            return false;
+            throw new NoKeyLoadedException('No key has been loaded');
+        }
+
+        if (!$this->isPublic) {
+            throw new UnsupportedOperationException('phpseclib does not allow the use of private keys to verify data');
         }
 
         switch ($padding) {

phpseclib/Exception/NoKeyLoadedException.php

@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * NoKeyLoadedException
+ *
+ * PHP version 5
+ *
+ * @category  Exception
+ * @package   NoKeyLoadedException
+ * @author    Jim Wigginton <terrafrost@php.net>
+ * @copyright 2015 Jim Wigginton
+ * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @link      http://phpseclib.sourceforge.net
+ */
+
+namespace phpseclib\Exception;
+
+/**
+ * NoKeyLoadedException
+ *
+ * @package NoKeyLoadedException
+ * @author  Jim Wigginton <terrafrost@php.net>
+ */
+class NoKeyLoadedException extends \RuntimeException
+{
+}

phpseclib/Exception/UnsupportedOperationException.php

@@ -0,0 +1,26 @@
+<?php
+
+/**
+ * UnsupportedOperationException
+ *
+ * PHP version 5
+ *
+ * @category  Exception
+ * @package   UnsupportedOperationException
+ * @author    Jim Wigginton <terrafrost@php.net>
+ * @copyright 2015 Jim Wigginton
+ * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @link      http://phpseclib.sourceforge.net
+ */
+
+namespace phpseclib\Exception;
+
+/**
+ * UnsupportedOperationException
+ *
+ * @package UnsupportedOperationException
+ * @author  Jim Wigginton <terrafrost@php.net>
+ */
+class UnsupportedOperationException extends \RuntimeException
+{
+}

phpseclib/File/X509.php

@@ -518,7 +518,7 @@ class X509
                 switch ($algorithm) {
                     case 'rsaEncryption':
                         $cert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey']
-                            = Base64::encode("\0" . Base64::decode(preg_replace('#-.+-|[\r\n]#', '', $cert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey'])));
+                            = "\0" . Base64::decode(preg_replace('#-.+-|[\r\n]#', '', $cert['tbsCertificate']['subjectPublicKeyInfo']['subjectPublicKey']));
                         /* "[For RSA keys] the parameters field MUST have ASN.1 type NULL for this algorithm identifier."
                            -- https://tools.ietf.org/html/rfc3279#section-2.3.1
 
@@ -1235,6 +1235,8 @@ class X509
             case 'rsaEncryption':
                 $rsa = new RSA();
                 $rsa->load($publicKey);
+//zzzzz
+                $rsa->setPublicKey();
 
                 switch ($signatureAlgorithm) {
                     case 'md2WithRSAEncryption':
@@ -2036,7 +2038,7 @@ class X509
                 switch ($algorithm) {
                     case 'rsaEncryption':
                         $csr['certificationRequestInfo']['subjectPKInfo']['subjectPublicKey']
-                            = Base64::encode("\0" . Base64::decode(preg_replace('#-.+-|[\r\n]#', '', $csr['certificationRequestInfo']['subjectPKInfo']['subjectPublicKey'])));
+                            = "\0" . Base64::decode(preg_replace('#-.+-|[\r\n]#', '', $csr['certificationRequestInfo']['subjectPKInfo']['subjectPublicKey']));
                         $csr['certificationRequestInfo']['subjectPKInfo']['algorithm']['parameters'] = null;
                         $csr['signatureAlgorithm']['parameters'] = null;
                         $csr['certificationRequestInfo']['signature']['parameters'] = null;
@@ -2122,7 +2124,6 @@ class X509
             case 'rsaEncryption':
                 $this->publicKey = new RSA();
                 $this->publicKey->load($key);
-                $this->publicKey->setPublicKey();
                 break;
             default:
                 $this->publicKey = null;
@@ -2157,7 +2158,7 @@ class X509
                 switch ($algorithm) {
                     case 'rsaEncryption':
                         $spkac['publicKeyAndChallenge']['spki']['subjectPublicKey']
-                            = Base64::encode("\0" . Base64::decode(preg_replace('#-.+-|[\r\n]#', '', $spkac['publicKeyAndChallenge']['spki']['subjectPublicKey'])));
+                            = "\0" . Base64::decode(preg_replace('#-.+-|[\r\n]#', '', $spkac['publicKeyAndChallenge']['spki']['subjectPublicKey']));
                 }
         }
 

tests/Unit/Crypt/RSA/ModeTest.php

@@ -132,4 +132,82 @@ U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ
         $rsa->load($rsa->getPublicKey());
         $this->assertTrue($rsa->verify($plaintext, $sig));
     }
+
+    /**
+     * @expectedException \phpseclib\Exception\UnsupportedOperationException
+     */
+    public function testPrivateEncrypt()
+    {
+        $rsa = new RSA();
+        $privatekey = '-----BEGIN RSA PRIVATE KEY-----
+MIICXAIBAAKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUp
+wmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ5
+1s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQABAoGAFijko56+qGyN8M0RVyaRAXz++xTqHBLh
+3tx4VgMtrQ+WEgCjhoTwo23KMBAuJGSYnRmoBZM3lMfTKevIkAidPExvYCdm5dYq3XToLkkLv5L2
+pIIVOFMDG+KESnAFV7l2c+cnzRMW0+b6f8mR1CJzZuxVLL6Q02fvLi55/mbSYxECQQDeAw6fiIQX
+GukBI4eMZZt4nscy2o12KyYner3VpoeE+Np2q+Z3pvAMd/aNzQ/W9WaI+NRfcxUJrmfPwIGm63il
+AkEAxCL5HQb2bQr4ByorcMWm/hEP2MZzROV73yF41hPsRC9m66KrheO9HPTJuo3/9s5p+sqGxOlF
+L0NDt4SkosjgGwJAFklyR1uZ/wPJjj611cdBcztlPdqoxssQGnh85BzCj/u3WqBpE2vjvyyvyI5k
+X6zk7S0ljKtt2jny2+00VsBerQJBAJGC1Mg5Oydo5NwD6BiROrPxGo2bpTbu/fhrT8ebHkTz2epl
+U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ
+37sJ5QsW+sJyoNde3xH8vdXhzU7eT82D6X/scw9RZz+/6rCJ4p0=
+-----END RSA PRIVATE KEY-----';
+        $rsa->load($privatekey);
+
+        $rsa->encrypt('hello, world!');
+    }
+
+    /**
+     * @expectedException \phpseclib\Exception\UnsupportedOperationException
+     */
+    public function testPublicSign()
+    {
+        $rsa = new RSA();
+        $rsa->load('-----BEGIN RSA PUBLIC KEY-----
+MIGJAoGBAMuqkz8ij+ESAaNvgocVGmapjlrIldmhRo4h2NX4e6IXiCLTSxASQtY4
+iqRnmyxqQSfaan2okTfQ6sP95bl8Qz8lgneW3ClC6RXG/wpJgsx7TXQ2kodlcKBF
+m4k72G75QXhZ+I40ZG7cjBf1/9egakR0a0X0MpeOrKCzMBLv9+mpAgMBAAE=
+-----END RSA PUBLIC KEY-----');
+
+        $rsa->sign('hello, world!');
+    }
+
+    /**
+     * @expectedException \phpseclib\Exception\UnsupportedOperationException
+     */
+    public function testPublicDecrypt()
+    {
+        $rsa = new RSA();
+        $rsa->load('-----BEGIN RSA PUBLIC KEY-----
+MIGJAoGBAMuqkz8ij+ESAaNvgocVGmapjlrIldmhRo4h2NX4e6IXiCLTSxASQtY4
+iqRnmyxqQSfaan2okTfQ6sP95bl8Qz8lgneW3ClC6RXG/wpJgsx7TXQ2kodlcKBF
+m4k72G75QXhZ+I40ZG7cjBf1/9egakR0a0X0MpeOrKCzMBLv9+mpAgMBAAE=
+-----END RSA PUBLIC KEY-----');
+
+        $rsa->decrypt('zzz');
+    }
+
+    /**
+     * @expectedException \phpseclib\Exception\UnsupportedOperationException
+     */
+    public function testPrivateVerify()
+    {
+        $rsa = new RSA();
+        $privatekey = '-----BEGIN RSA PRIVATE KEY-----
+MIICXAIBAAKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUp
+wmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ5
+1s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQABAoGAFijko56+qGyN8M0RVyaRAXz++xTqHBLh
+3tx4VgMtrQ+WEgCjhoTwo23KMBAuJGSYnRmoBZM3lMfTKevIkAidPExvYCdm5dYq3XToLkkLv5L2
+pIIVOFMDG+KESnAFV7l2c+cnzRMW0+b6f8mR1CJzZuxVLL6Q02fvLi55/mbSYxECQQDeAw6fiIQX
+GukBI4eMZZt4nscy2o12KyYner3VpoeE+Np2q+Z3pvAMd/aNzQ/W9WaI+NRfcxUJrmfPwIGm63il
+AkEAxCL5HQb2bQr4ByorcMWm/hEP2MZzROV73yF41hPsRC9m66KrheO9HPTJuo3/9s5p+sqGxOlF
+L0NDt4SkosjgGwJAFklyR1uZ/wPJjj611cdBcztlPdqoxssQGnh85BzCj/u3WqBpE2vjvyyvyI5k
+X6zk7S0ljKtt2jny2+00VsBerQJBAJGC1Mg5Oydo5NwD6BiROrPxGo2bpTbu/fhrT8ebHkTz2epl
+U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ
+37sJ5QsW+sJyoNde3xH8vdXhzU7eT82D6X/scw9RZz+/6rCJ4p0=
+-----END RSA PRIVATE KEY-----';
+        $rsa->load($privatekey);
+
+        $rsa->verify('hello, world!', 'dummysignature');
+    }
 }

tests/Unit/File/X509/SPKACTest.php

@@ -46,8 +46,7 @@ class Unit_File_X509_SPKACTest extends PhpseclibTestCase
 
     public function testSaveSPKAC()
     {
-        $privKey = new RSA();
+        extract(RSA::createKey());
-        extract($privKey->createKey());
 
         $x509 = new X509();
         $x509->setPrivateKey($privatekey);
@@ -59,7 +58,7 @@ class Unit_File_X509_SPKACTest extends PhpseclibTestCase
         $this->assertInternalType('string', $x509->saveSPKAC($spkac));
 
         $x509 = new X509();
-        $x509->setPrivateKey($privKey);
+        $x509->setPrivateKey($privatekey);
 
         $spkac = $x509->signSPKAC();
         $this->assertInternalType('array', $spkac);