ASN1: revamp how OIDs are handled

phpseclib/File/ASN1.php

@@ -515,24 +515,7 @@ class File_ASN1
                 }
                 break;
             case FILE_ASN1_TYPE_OBJECT_IDENTIFIER:
-                $temp = ord($content[$content_pos++]);
+                $current['content'] = $this->_decodeOID(substr($content, $content_pos));
-                $current['content'] = sprintf('%d.%d', floor($temp / 40), $temp % 40);
-                $valuen = 0;
-                // process septets
-                $content_len = strlen($content);
-                while ($content_pos < $content_len) {
-                    $temp = ord($content[$content_pos++]);
-                    $valuen <<= 7;
-                    $valuen |= $temp & 0x7F;
-                    if (~$temp & 0x80) {
-                        $current['content'].= ".$valuen";
-                        $valuen = 0;
-                    }
-                }
-                // the eighth bit of the last byte should not be 1
-                //if ($temp >> 7) {
-                //    return false;
-                //}
                 break;
             /* Each character string type shall be encoded as if it had been declared:
                [UNIVERSAL x] IMPLICIT OCTET STRING
@@ -1111,27 +1094,7 @@ class File_ASN1
                 $value = base64_decode($source);
                 break;
             case FILE_ASN1_TYPE_OBJECT_IDENTIFIER:
-                $oid = preg_match('#(?:\d+\.)+#', $source) ? $source : array_search($source, $this->oids);
+                $value = $this->_encodeOID($source);
-                if ($oid === false) {
-                    user_error('Invalid OID');
-                    return false;
-                }
-                $value = '';
-                $parts = explode('.', $oid);
-                $value = chr(40 * $parts[0] + $parts[1]);
-                for ($i = 2; $i < count($parts); $i++) {
-                    $temp = '';
-                    if (!$parts[$i]) {
-                        $temp = "\0";
-                    } else {
-                        while ($parts[$i]) {
-                            $temp = chr(0x80 | ($parts[$i] & 0x7F)) . $temp;
-                            $parts[$i] >>= 7;
-                        }
-                        $temp[strlen($temp) - 1] = $temp[strlen($temp) - 1] & chr(0x7F);
-                    }
-                    $value.= $temp;
-                }
                 break;
             case FILE_ASN1_TYPE_ANY:
                 $loc = $this->location;
@@ -1230,6 +1193,108 @@ class File_ASN1
         return pack('Ca*', 0x80 | strlen($temp), $temp);
     }
 
+    /**
+     * BER-decode the OID
+     *
+     * Called by _decode_ber()
+     *
+     * @access private
+     * @param string $content
+     * @return string
+     */
+    function _decodeOID($content)
+    {
+        static $eighty;
+        if (!$eighty) {
+            $eighty = new Math_BigInteger(80);
+        }
+
+        $oid = array();
+        $pos = 0;
+        $len = strlen($content);
+        $n = new Math_BigInteger();
+        while ($pos < $len) {
+            $temp = ord($content[$pos++]);
+            $n = $n->bitwise_leftShift(7);
+            $n = $n->bitwise_or(new Math_BigInteger($temp & 0x7F));
+            if (~$temp & 0x80) {
+                $oid[] = $n;
+                $n = new Math_BigInteger();
+            }
+        }
+        $part1 = array_shift($oid);
+        $first = floor(ord($content[0]) / 40);
+        /*
+          "This packing of the first two object identifier components recognizes that only three values are allocated from the root
+           node, and at most 39 subsequent values from nodes reached by X = 0 and X = 1."
+
+          -- https://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#page=22
+        */
+        if ($first <= 2) { // ie. 0 <= ord($content[0]) < 120 (0x78)
+            array_unshift($oid, ord($content[0]) % 40);
+            array_unshift($oid, $first);
+        } else {
+            array_unshift($oid, $part1->subtract($eighty));
+            array_unshift($oid, 2);
+        }
+
+        return implode('.', $oid);
+    }
+
+    /**
+     * DER-encode the OID
+     *
+     * Called by _encode_der()
+     *
+     * @access private
+     * @param string $content
+     * @return string
+     */
+    function _encodeOID($source)
+    {
+        static $mask, $zero, $forty;
+        if (!$mask) {
+            $mask = new Math_BigInteger(0x7F);
+            $zero = new Math_BigInteger();
+            $forty = new Math_BigInteger(40);
+        }
+
+        $oid = preg_match('#(?:\d+\.)+#', $source) ? $source : array_search($source, $this->oids);
+        if ($oid === false) {
+            user_error('Invalid OID');
+            return false;
+        }
+        $parts = explode('.', $oid);
+        $part1 = array_shift($parts);
+        $part2 = array_shift($parts);
+
+        $first = new Math_BigInteger($part1);
+        $first = $first->multiply($forty);
+        $first = $first->add(new Math_BigInteger($part2));
+
+        array_unshift($parts, $first->toString());
+
+        $value = '';
+        foreach ($parts as $part) {
+            if (!$part) {
+                $temp = "\0";
+            } else {
+                $temp = '';
+                $part = new Math_BigInteger($part);
+                while (!$part->equals($zero)) {
+                    $submask = $part->bitwise_and($mask);
+                    $submask->setPrecision(8);
+                    $temp = (chr(0x80) | $submask->toBytes()) . $temp;
+                    $part = $part->bitwise_rightShift(7);
+                }
+                $temp[strlen($temp) - 1] = $temp[strlen($temp) - 1] & chr(0x7F);
+            }
+            $value.= $temp;
+        }
+
+        return $value;
+    }
+
     /**
      * BER-decode the time (using UNIX time)
      *

tests/Unit/File/ASN1Test.php

@@ -341,4 +341,26 @@ class Unit_File_ASN1Test extends PhpseclibTestCase
         $asn1 = new File_ASN1();
         $asn1->decodeBER($data);
     }
+
+    /**
+     * @group github1367
+     */
+    public function testOIDs()
+    {
+        // from the example in 8.19.5 in the following:
+        // https://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#page=22
+        $orig = pack('H*', '813403');
+        $asn1 = new File_ASN1();
+        $new = $asn1->_decodeOID($orig);
+        $this->assertSame('2.100.3', $new);
+        $this->assertSame($orig, $asn1->_encodeOID($new));
+
+        // UUID OID from the following:
+        // https://healthcaresecprivacy.blogspot.com/2011/02/creating-and-using-unique-id-uuid-oid.html
+        $orig = '2.25.329800735698586629295641978511506172918';
+        $asn1 = new File_ASN1();
+        $new = $asn1->_encodeOID($orig);
+        $this->assertSame(pack('H*', '6983f09da7ebcfdee0c7a1a7b2c0948cc8f9d776'), $new);
+        $this->assertSame($orig, $asn1->_decodeOID($new));
+    }
 }