1 files changed, 106 insertions, 0 deletions
diff --git a/crypto/asn1hex.js b/crypto/asn1hex.js
new file mode 100644
index 0000000..15987bc
--- /dev/null
+++ b/crypto/asn1hex.js
@@ -0,0 +1,106 @@
+//
+// asn1hex.js - Hexadecimal represented ASN.1 string library
+//
+//
+// version: 1.0 (2010-Jun-03)
+//
+// Copyright (c) 2010 Kenji Urushima (kenji.urushima@gmail.com)
+//
+// This software is licensed under the terms of the MIT License.
+// http://www.opensource.org/licenses/mit-license.php
+//
+// The above copyright and license notice shall be 
+// included in all copies or substantial portions of the Software.
+// 
+//
+// Depends on:
+//
+
+// MEMO:
+//   f('3082025b02...', 2) ... 82025b ... 3bytes
+//   f('020100', 2) ... 01 ... 1byte
+//   f('0203001...', 2) ... 03 ... 1byte
+//   f('02818003...', 2) ... 8180 ... 2bytes
+//   f('3080....0000', 2) ... 80 ... -1
+//
+//   Requirements:
+//   - ASN.1 type octet length MUST be 1. 
+//     (i.e. ASN.1 primitives like SET, SEQUENCE, INTEGER, OCTETSTRING ...)
+//   - 
+function _asnhex_getByteLengthOfL_AtObj(s, pos) {
+  if (s.substring(pos + 2, pos + 3) != '8') return 1;
+  var i = parseInt(s.substring(pos + 3, pos + 4));
+  if (i == 0) return -1; 		// length octet '80' indefinite length
+  if (0 < i && i < 10) return i + 1;	// including '8?' octet;
+  return -2;				// malformed format
+}
+
+function _asnhex_getHexOfL_AtObj(s, pos) {
+  var len = _asnhex_getByteLengthOfL_AtObj(s, pos);
+  if (len < 1) return '';
+  return s.substring(pos + 2, pos + 2 + len * 2);
+}
+
+//
+//   getting ASN.1 length value at the position 'idx' of
+//   hexa decimal string 's'.
+//
+//   f('3082025b02...', 0) ... 82025b ... ???
+//   f('020100', 0) ... 01 ... 1
+//   f('0203001...', 0) ... 03 ... 3
+//   f('02818003...', 0) ... 8180 ... 128
+function _asnhex_getIntOfL_AtObj(s, pos) {
+  var hLength = _asnhex_getHexOfL_AtObj(s, pos);
+  if (hLength == '') return -1;
+  var bi;
+  if (parseInt(hLength.substring(0, 1)) < 8) {
+     bi = parseBigInt(hLength, 16);
+  } else {
+     bi = parseBigInt(hLength.substring(2), 16);
+  }
+  return bi.intValue();
+}
+
+//
+// get ASN.1 value starting string position 
+// for ASN.1 object refered by index 'idx'.
+//
+function _asnhex_getStartPosOfV_AtObj(s, pos) {
+  var l_len = _asnhex_getByteLengthOfL_AtObj(s, pos);
+  if (l_len < 0) return l_len;
+  return pos + (l_len + 1) * 2;
+}
+
+function _asnhex_getHexOfV_AtObj(s, pos) {
+  var pos1 = _asnhex_getStartPosOfV_AtObj(s, pos);
+  var len = _asnhex_getIntOfL_AtObj(s, pos);
+  return s.substring(pos1, pos1 + len * 2);
+}
+
+function _asnhex_getPosOfNextSibling_AtObj(s, pos) {
+  var pos1 = _asnhex_getStartPosOfV_AtObj(s, pos);
+  var len = _asnhex_getIntOfL_AtObj(s, pos);
+  return pos1 + len * 2;
+}
+
+function _asnhex_getPosArrayOfChildren_AtObj(h, pos) {
+  var a = new Array();
+  var p0 = _asnhex_getStartPosOfV_AtObj(h, pos);
+  a.push(p0);
+
+  var len = _asnhex_getIntOfL_AtObj(h, pos);
+  var p = p0;
+  var k = 0;
+  while (1) {
+    var pNext = _asnhex_getPosOfNextSibling_AtObj(h, p);
+    if (pNext == null || (pNext - p0  >= (len * 2))) break;
+    if (k >= 200) break;
+
+    a.push(pNext);
+    p = pNext;
+
+    k++;
+  }
+
+  return a;
+}