RSA: auto-detect public keys vs private keys

phpseclib/Crypt/RSA.php

@@ -477,7 +477,7 @@ class Crypt_RSA
                 case extension_loaded('openssl') && version_compare(PHP_VERSION, '4.2.0', '>=') && file_exists($this->configFile):
                     // some versions of XAMPP have mismatched versions of OpenSSL which causes it not to work
                     ob_start();
-                    phpinfo();
+                    @phpinfo();
                     $content = ob_get_contents();
                     ob_end_clean();
 
@@ -1478,6 +1478,19 @@ class Crypt_RSA
             $this->publicExponent = false;
         }
 
+        switch ($type) {
+            case CRYPT_RSA_PUBLIC_FORMAT_OPENSSH:
+            case CRYPT_RSA_PUBLIC_FORMAT_RAW:
+                $this->setPublicKey();
+                break;
+            case CRYPT_RSA_PRIVATE_FORMAT_PKCS1:
+                switch (true) {
+                    case strpos($key, '-BEGIN PUBLIC KEY-') !== false:
+                    case strpos($key, '-BEGIN RSA PUBLIC KEY-') !== false:
+                        $this->setPublicKey();
+                }
+        }
+
         return true;
     }
 
@@ -1504,7 +1517,9 @@ class Crypt_RSA
      * used in certain contexts.  For example, in SSH-2, RSA authentication works by sending the public key along with a
      * message signed by the private key to the server.  The SSH-2 server looks the public key up in an index of public keys
      * and if it's present then proceeds to verify the signature.  Problem is, if your private key doesn't include the public
-     * exponent this won't work unless you manually add the public exponent.
+     * exponent this won't work unless you manually add the public exponent. phpseclib tries to guess if the key being used
+     * is the public key but in the event that it guesses incorrectly you might still want to explicitly set the key as being
+     * public.
      *
      * Do note that when a new key is loaded the index will be cleared.
      *
@@ -1560,6 +1575,40 @@ class Crypt_RSA
         return true;
     }
 
+    /**
+     * Defines the private key
+     *
+     * If phpseclib guessed a private key was a public key and loaded it as such it might be desirable to force
+     * phpseclib to treat the key as a private key. This function will do that.
+     *
+     * Do note that when a new key is loaded the index will be cleared.
+     *
+     * Returns true on success, false on failure
+     *
+     * @see getPublicKey()
+     * @access public
+     * @param String $key optional
+     * @param Integer $type optional
+     * @return Boolean
+     */
+    function setPrivateKey($key = false, $type = false)
+    {
+        if ($key === false && !empty($this->publicExponent)) {
+            unset($this->publicExponent);
+            return true;
+        }
+
+        $rsa = new Crypt_RSA();
+        if (!$rsa->loadKey($key, $type)) {
+            return false;
+        }
+        unset($rsa->publicExponent);
+
+        // don't overwrite the old key if the new key is invalid
+        $this->loadKey($rsa);
+        return true;
+    }
+
     /**
      * Returns the public key
      *

tests/Crypt/RSA/LoadKeyTest.php

@@ -36,7 +36,7 @@ U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ
 37sJ5QsW+sJyoNde3xH8vdXhzU7eT82D6X/scw9RZz+/6rCJ4p0=
 -----END RSA PRIVATE KEY-----';
 
-        $this->assertTrue($rsa->loadKey($key));
+        $this->assertTrue($rsa->loadKey($key) && is_string($rsa->getPrivateKey()));
     }
 
     public function testPKCS1SpacesKey()
@@ -58,7 +58,7 @@ U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ
 -----END RSA PRIVATE KEY-----';
         $key = str_replace(array("\r", "\n", "\r\n"), ' ', $key);
 
-        $this->assertTrue($rsa->loadKey($key));
+        $this->assertTrue($rsa->loadKey($key) && is_string($rsa->getPrivateKey()));
     }
 
     public function testPKCS1NoHeaderKey()
@@ -77,7 +77,7 @@ X6zk7S0ljKtt2jny2+00VsBerQJBAJGC1Mg5Oydo5NwD6BiROrPxGo2bpTbu/fhrT8ebHkTz2epl
 U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ
 37sJ5QsW+sJyoNde3xH8vdXhzU7eT82D6X/scw9RZz+/6rCJ4p0=';
 
-        $this->assertTrue($rsa->loadKey($key));
+        $this->assertTrue($rsa->loadKey($key) && is_string($rsa->getPrivateKey()));
     }
 
     public function testPKCS1NoWhitespaceNoHeaderKey()
@@ -95,7 +95,7 @@ U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ
                'X6zk7S0ljKtt2jny2+00VsBerQJBAJGC1Mg5Oydo5NwD6BiROrPxGo2bpTbu/fhrT8ebHkTz2epl' .
                'U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ' .
                '37sJ5QsW+sJyoNde3xH8vdXhzU7eT82D6X/scw9RZz+/6rCJ4p0=';
-        $this->assertTrue($rsa->loadKey($key));
+        $this->assertTrue($rsa->loadKey($key) && is_string($rsa->getPrivateKey()));
     }
 
     public function testRawPKCS1Key()
@@ -115,6 +115,67 @@ U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ
                '37sJ5QsW+sJyoNde3xH8vdXhzU7eT82D6X/scw9RZz+/6rCJ4p0=';
         $key = base64_decode($key);
 
-        $this->assertTrue($rsa->loadKey($key));
+        $this->assertTrue($rsa->loadKey($key) && is_string($rsa->getPrivateKey()));
+    }
+
+    public function testPubKey1()
+    {
+        $rsa = new Crypt_RSA();
+
+        $key = '-----BEGIN RSA PUBLIC KEY-----
+MIIBCgKCAQEA61BjmfXGEvWmegnBGSuS+rU9soUg2FnODva32D1AqhwdziwHINFa
+D1MVlcrYG6XRKfkcxnaXGfFDWHLEvNBSEVCgJjtHAGZIm5GL/KA86KDp/CwDFMSw
+luowcXwDwoyinmeOY9eKyh6aY72xJh7noLBBq1N0bWi1e2i+83txOCg4yV2oVXhB
+o8pYEJ8LT3el6Smxol3C1oFMVdwPgc0vTl25XucMcG/ALE/KNY6pqC2AQ6R2ERlV
+gPiUWOPatVkt7+Bs3h5Ramxh7XjBOXeulmCpGSynXNcpZ/06+vofGi/2MlpQZNhH
+Ao8eayMp6FcvNucIpUndo1X8dKMv3Y26ZQIDAQAB
+-----END RSA PUBLIC KEY-----';
+
+        $this->assertTrue($rsa->loadKey($key) && is_string($rsa->getPublicKey()) && $rsa->getPrivateKey() === false);
+    }
+
+    public function testPubKey2()
+    {
+        $rsa = new Crypt_RSA();
+
+        $key = '-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA61BjmfXGEvWmegnBGSuS
++rU9soUg2FnODva32D1AqhwdziwHINFaD1MVlcrYG6XRKfkcxnaXGfFDWHLEvNBS
+EVCgJjtHAGZIm5GL/KA86KDp/CwDFMSwluowcXwDwoyinmeOY9eKyh6aY72xJh7n
+oLBBq1N0bWi1e2i+83txOCg4yV2oVXhBo8pYEJ8LT3el6Smxol3C1oFMVdwPgc0v
+Tl25XucMcG/ALE/KNY6pqC2AQ6R2ERlVgPiUWOPatVkt7+Bs3h5Ramxh7XjBOXeu
+lmCpGSynXNcpZ/06+vofGi/2MlpQZNhHAo8eayMp6FcvNucIpUndo1X8dKMv3Y26
+ZQIDAQAB
+-----END PUBLIC KEY-----';
+
+        $this->assertTrue($rsa->loadKey($key) && is_string($rsa->getPublicKey()) && $rsa->getPrivateKey() === false);
+    }
+
+    public function testPubKey3()
+    {
+        $rsa = new Crypt_RSA();
+
+        $key = 'ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4e' .
+               'CZ0FPqri0cb2JZfXJ/DgYSF6vUpwmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMS' .
+               'GkVb1/3j+skZ6UtW+5u09lHNsj6tQ51s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZw== ' .
+               'phpseclib-generated-key';
+
+        $this->assertTrue($rsa->loadKey($key) && is_string($rsa->getPublicKey()) && $rsa->getPrivateKey() === false);
+    }
+
+    public function testSetPrivate()
+    {
+        $rsa = new Crypt_RSA();
+
+        $key = '-----BEGIN RSA PUBLIC KEY-----
+MIIBCgKCAQEA61BjmfXGEvWmegnBGSuS+rU9soUg2FnODva32D1AqhwdziwHINFa
+D1MVlcrYG6XRKfkcxnaXGfFDWHLEvNBSEVCgJjtHAGZIm5GL/KA86KDp/CwDFMSw
+luowcXwDwoyinmeOY9eKyh6aY72xJh7noLBBq1N0bWi1e2i+83txOCg4yV2oVXhB
+o8pYEJ8LT3el6Smxol3C1oFMVdwPgc0vTl25XucMcG/ALE/KNY6pqC2AQ6R2ERlV
+gPiUWOPatVkt7+Bs3h5Ramxh7XjBOXeulmCpGSynXNcpZ/06+vofGi/2MlpQZNhH
+Ao8eayMp6FcvNucIpUndo1X8dKMv3Y26ZQIDAQAB
+-----END RSA PUBLIC KEY-----';
+
+        $this->assertTrue($rsa->loadKey($key) && $rsa->setPrivateKey() && is_string("$rsa") && $rsa->getPublicKey() === false);
     }
 }