v1.1.8: bugfix increase incorrect loop limit for eager parsing

README.md

@@ -1,6 +1,6 @@
 # Bluecrypt ASN.1 Parser
 
-An ASN.1 parser in less than 100 lines of Vanilla JavaScript,
+An ASN.1 decoder in less than 100 lines of Vanilla JavaScript,
 part of the Bluecrypt suite.
 <br>
 <small>(< 150 with newlines and comments)</small>
@@ -17,6 +17,10 @@ part of the Bluecrypt suite.
   * [x] Online [Demo](https://coolaj86.com/demos/asn1-parser/)
   * [ ] Node.js (built, publishing soon)
 
+### Need an ASN.1 Builder too?
+
+Check out https://git.coolaj86.com/coolaj86/asn1-packer.js/
+
 # Demo
 
 <https://coolaj86.com/demos/asn1-parser/>

asn1-parser.js

@@ -1,3 +1,7 @@
+// Copyright 2018 AJ ONeal. All rights reserved
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 ;(function (exports) {
 'use strict';
 
@@ -13,87 +17,102 @@ var PEM = exports.PEM;
 // Parser
 //
 
-ASN1.ELOOP = "uASN1.js Error: iterated over 15+ elements (probably a malformed file)";
-ASN1.EDEEP = "uASN1.js Error: element nested 20+ layers deep (probably a malformed file)";
+// Although I've only seen 9 max in https certificates themselves,
+// but each domain list could have up to 100
+ASN1.ELOOPN = 102;
+ASN1.ELOOP = "uASN1.js Error: iterated over " + ASN1.ELOOPN + "+ elements (probably a malformed file)";
+// I've seen https certificates go 29 deep
+ASN1.EDEEPN = 60;
+ASN1.EDEEP = "uASN1.js Error: element nested " + ASN1.EDEEPN + "+ layers deep (probably a malformed file)";
 // Container Types are Sequence 0x30, Container Array? (0xA0, 0xA1)
-// Value Types are Integer 0x02, Null 0x05, Object ID 0x06, Value Array? (0x82)
+// Value Types are Boolean 0x01, Integer 0x02, Null 0x05, Object ID 0x06, String 0x0C, 0x16, 0x13, 0x1e Value Array? (0x82)
 // Bit String (0x03) and Octet String (0x04) may be values or containers
 // Sometimes Bit String is used as a container (RSA Pub Spki)
 ASN1.CTYPES = [ 0x30, 0x31, 0xa0, 0xa1 ];
-ASN1.VTYPES = [ 0x02, 0x05, 0x06, 0x82 ];
-ASN1.parse = function parseAsn1(buf, depth, ws) {
-  if (!ws) { ws = ''; }
-  if (!depth) { depth = 0; }
-  if (depth >= 20) { throw new Error(ASN1.EDEEP); }
+ASN1.VTYPES = [ 0x01, 0x02, 0x05, 0x06, 0x0c, 0x82 ];
+ASN1.parse = function parseAsn1Helper(buf) {
+  //var ws = '  ';
+  function parseAsn1(buf, depth, eager) {
+    if (depth.length >= ASN1.EDEEPN) { throw new Error(ASN1.EDEEP); }
 
-  var index = 2; // we know, at minimum, data starts after type (0) and lengthSize (1)
-  var asn1 = { type: buf[0], lengthSize: 0, length: buf[1] };
-  var child;
-  var iters = 0;
-  var adjust = 0;
-  var adjustedLen;
+    var index = 2; // we know, at minimum, data starts after type (0) and lengthSize (1)
+    var asn1 = { type: buf[0], lengthSize: 0, length: buf[1] };
+    var child;
+    var iters = 0;
+    var adjust = 0;
+    var adjustedLen;
 
-  // Determine how many bytes the length uses, and what it is
-  if (0x80 & asn1.length) {
-    asn1.lengthSize = 0x7f & asn1.length;
-    // I think that buf->hex->int solves the problem of Endianness... not sure
-    asn1.length = parseInt(Enc.bufToHex(buf.slice(index, index + asn1.lengthSize)), 16);
-    index += asn1.lengthSize;
-  }
-
-  // High-order bit Integers have a leading 0x00 to signify that they are positive.
-  // Bit Streams use the first byte to signify padding, which x.509 doesn't use.
-  if (0x00 === buf[index] && (0x02 === asn1.type || 0x03 === asn1.type)) {
-    // However, 0x00 on its own is a valid number
-    if (asn1.length > 1) {
-      index += 1;
-      adjust = -1;
+    // Determine how many bytes the length uses, and what it is
+    if (0x80 & asn1.length) {
+      asn1.lengthSize = 0x7f & asn1.length;
+      // I think that buf->hex->int solves the problem of Endianness... not sure
+      asn1.length = parseInt(Enc.bufToHex(buf.slice(index, index + asn1.lengthSize)), 16);
+      index += asn1.lengthSize;
     }
-  }
-  adjustedLen = asn1.length + adjust;
 
-  //console.warn(ws + '0x' + Enc.numToHex(asn1.type), index, 'len:', asn1.length, asn1);
-
-  function parseChildren(eager) {
-    asn1.children = [];
-    //console.warn('1 len:', (2 + asn1.lengthSize + asn1.length), 'idx:', index, 'clen:', 0);
-    while (iters < 15 && index < (2 + asn1.length + asn1.lengthSize)) {
-      iters += 1;
-      child = ASN1.parse(buf.slice(index, index + adjustedLen), (depth || 0) + 1, ws + '  ');
-      // The numbers don't match up exactly and I don't remember why...
-      // probably something with adjustedLen or some such, but the tests pass
-      index += (2 + child.lengthSize + child.length);
-      //console.warn('2 len:', (2 + asn1.lengthSize + asn1.length), 'idx:', index, 'clen:', (2 + child.lengthSize + child.length));
-      if (index > (2 + asn1.lengthSize + asn1.length)) {
-        if (!eager) { console.error(JSON.stringify(asn1, ASN1._replacer, 2)); }
-        throw new Error("Parse error: child value length (" + child.length
-          + ") is greater than remaining parent length (" + (asn1.length - index)
-          + " = " + asn1.length + " - " + index + ")");
+    // High-order bit Integers have a leading 0x00 to signify that they are positive.
+    // Bit Streams use the first byte to signify padding, which x.509 doesn't use.
+    if (0x00 === buf[index] && (0x02 === asn1.type || 0x03 === asn1.type)) {
+      // However, 0x00 on its own is a valid number
+      if (asn1.length > 1) {
+        index += 1;
+        adjust = -1;
       }
-      asn1.children.push(child);
-      //console.warn(ws + '0x' + Enc.numToHex(asn1.type), index, 'len:', asn1.length, asn1);
     }
-    if (index !== (2 + asn1.lengthSize + asn1.length)) {
-      //console.warn('index:', index, 'length:', (2 + asn1.lengthSize + asn1.length));
-      throw new Error("premature end-of-file");
-    }
-    if (iters >= 15) { throw new Error(ASN1.ELOOP); }
+    adjustedLen = asn1.length + adjust;
 
-    delete asn1.value;
-    return asn1;
+    //console.warn(depth.join(ws) + '0x' + Enc.numToHex(asn1.type), index, 'len:', asn1.length, asn1);
+
+    function parseChildren(eager) {
+      asn1.children = [];
+      //console.warn('1 len:', (2 + asn1.lengthSize + asn1.length), 'idx:', index, 'clen:', 0);
+      while (iters < ASN1.ELOOPN && index < (2 + asn1.length + asn1.lengthSize)) {
+        iters += 1;
+        depth.length += 1;
+        child = parseAsn1(buf.slice(index, index + adjustedLen), depth, eager);
+        depth.length -= 1;
+        // The numbers don't match up exactly and I don't remember why...
+        // probably something with adjustedLen or some such, but the tests pass
+        index += (2 + child.lengthSize + child.length);
+        //console.warn('2 len:', (2 + asn1.lengthSize + asn1.length), 'idx:', index, 'clen:', (2 + child.lengthSize + child.length));
+        if (index > (2 + asn1.lengthSize + asn1.length)) {
+          if (!eager) { console.error(JSON.stringify(asn1, ASN1._replacer, 2)); }
+          throw new Error("Parse error: child value length (" + child.length
+            + ") is greater than remaining parent length (" + (asn1.length - index)
+            + " = " + asn1.length + " - " + index + ")");
+        }
+        asn1.children.push(child);
+        //console.warn(depth.join(ws) + '0x' + Enc.numToHex(asn1.type), index, 'len:', asn1.length, asn1);
+      }
+      if (index !== (2 + asn1.lengthSize + asn1.length)) {
+        //console.warn('index:', index, 'length:', (2 + asn1.lengthSize + asn1.length));
+        throw new Error("premature end-of-file");
+      }
+      if (iters >= ASN1.ELOOPN) { throw new Error(ASN1.ELOOP); }
+
+      delete asn1.value;
+      return asn1;
+    }
+
+    // Recurse into types that are _always_ containers
+    if (-1 !== ASN1.CTYPES.indexOf(asn1.type)) { return parseChildren(eager); }
+
+    // Return types that are _always_ values
+    asn1.value = buf.slice(index, index + adjustedLen);
+    if (-1 !== ASN1.VTYPES.indexOf(asn1.type)) { return asn1; }
+
+    // For ambigious / unknown types, recurse and return on failure
+    // (and return child array size to zero)
+    try { return parseChildren(true); }
+    catch(e) { asn1.children.length = 0; return asn1; }
   }
 
-  // Recurse into types that are _always_ containers
-  if (-1 !== ASN1.CTYPES.indexOf(asn1.type)) { return parseChildren(); }
-
-  // Return types that are _always_ values
-  asn1.value = buf.slice(index, index + adjustedLen);
-  if (-1 !== ASN1.VTYPES.indexOf(asn1.type)) { return asn1; }
-
-  // For ambigious / unknown types, recurse and return on failure
-  // (and return child array size to zero)
-  try { return parseChildren(true); }
-  catch(e) { asn1.children.length = 0; return asn1; }
+  var asn1 = parseAsn1(buf, []);
+  var len = buf.byteLength || buf.length;
+  if (len !== 2 + asn1.lengthSize + asn1.length) {
+    throw new Error("Length of buffer does not match length of ASN.1 sequence.");
+  }
+  return asn1;
 };
 ASN1._replacer = function (k, v) {
   if ('type' === k) { return '0x' + Enc.numToHex(v); }

index.html

@@ -12,30 +12,55 @@
 <body>
   <h1>Bluecrypt ASN.1 Parser</h1>
 
+  <h2>PEM (base64-encoded DER)</h2>
   <textarea class="js-input" placeholder="Paste a PEM here">-----BEGIN PUBLIC KEY-----
 MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEIT1SWLxsacPiE5Z16jkopAn8/+85
 rMjgyCokrnjDft6Y/YnA4A50yZe7CnFsqeDcpnPbubP6cpYiVcnevNIYyg==
 -----END PUBLIC KEY-----</textarea>
 
+  <h2>Hex</h2>
   <pre><code class="js-hex"> </code></pre>
 
+  <h2>ASN.1 Array</h2>
+  <pre><code class="js-array"> </code></pre>
+
+  <h2>ASN.1 Object</h2>
   <pre><code class="js-json"> </code></pre>
 
   <br>
-  <p>Made with <a href="https://git.coolaj86.com/coolaj86/asn1-parser/">asn1-parser.js</a></p>
+  <p>Made with <a href="https://git.coolaj86.com/coolaj86/asn1-parser.js/">asn1-parser.js</a></p>
 
   <script src="./asn1-parser.js"></script>
   <script>
     var $input = document.querySelector('.js-input');
 
+    function toArray(next) {
+      console.log(next);
+      if (next.value) {
+        return [next.type, Enc.bufToHex(next.value)];
+      }
+      return [next.type, next.children.map(function (child) {
+        return toArray(child);
+      })];
+    }
+
     function convert() {
       console.log('keyup');
-      var pem = PEM.parseBlock(document.querySelector('.js-input').value);
-      var hex = Enc.bufToHex(pem.der);
-      document.querySelector('.js-hex').innerText = hex
-        .match(/.{2}/g).join(' ').match(/.{1,24}/g).join(' ').match(/.{1,50}/g).join('\n');
-      var json = ASN1.parse(pem.der);
+      var json;
+
+      try {
+        var pem = PEM.parseBlock(document.querySelector('.js-input').value);
+        var hex = Enc.bufToHex(pem.der);
+        var arr = [];
+        document.querySelector('.js-hex').innerText = hex
+          .match(/.{2}/g).join(' ').match(/.{1,24}/g).join(' ').match(/.{1,50}/g).join('\n');
+        json = ASN1.parse(pem.der);
+      } catch(e) {
+        json = { error: { message: e.message } };
+      }
+
       document.querySelector('.js-json').innerText = JSON.stringify(json, ASN1._replacer, 2);
+      document.querySelector('.js-array').innerText = JSON.stringify(toArray(json), null, 2);
     }
 
     $input.addEventListener('keyup', convert);

package.json

@@ -1,9 +1,12 @@
 {
   "name": "asn1-parser",
-  "version": "1.1.1",
+  "version": "1.1.8",
   "description": "An ASN.1 parser in less than 100 lines of Vanilla JavaScript, part of the Bluecrypt suite.",
   "homepage": "https://git.coolaj86.com/coolaj86/asn1-parser.js",
   "main": "asn1-parser.js",
+  "scripts": {
+    "prepare": "uglifyjs asn1-parser.js > asn1-parser.min.js"
+  },
   "directories": {
     "lib": "lib"
   },