Parse cookie-pair part without regexp

Specifically to avoid any more hidden ReDoS in those regexes.

Seems to run tests in 6.9s vs 7.0s so might be a bit of a speed bonus on
some platforms!

Author: stash-sfdc

lib/cookie.js

@@ -48,25 +48,14 @@ var DATE_DELIM = /[\x09\x20-\x2F\x3B-\x40\x5B-\x60\x7B-\x7E]/;
 
 // From RFC6265 S4.1.1
 // note that it excludes \x3B ";"
-var COOKIE_OCTET  = /[\x21\x23-\x2B\x2D-\x3A\x3C-\x5B\x5D-\x7E]/;
-var COOKIE_OCTETS = new RegExp('^'+COOKIE_OCTET.source+'+$');
+var COOKIE_OCTETS = /^[\x21\x23-\x2B\x2D-\x3A\x3C-\x5B\x5D-\x7E]+$/;
 
 var CONTROL_CHARS = /[\x00-\x1F]/;
 
-// For COOKIE_PAIR and LOOSE_COOKIE_PAIR below, the number of spaces has been
-// restricted to 256 to side-step a ReDoS issue reported here:
-// https://github.com/salesforce/tough-cookie/issues/92
-
-// Double quotes are part of the value (see: S4.1.1).
-// '\r', '\n' and '\0' should be treated as a terminator in the "relaxed" mode
-// (see: https://github.com/ChromiumWebApps/chromium/blob/b3d3b4da8bb94c1b2e061600df106d590fda3620/net/cookies/parsed_cookie.cc#L60)
-// '=' and ';' are attribute/values separators
-// (see: https://github.com/ChromiumWebApps/chromium/blob/b3d3b4da8bb94c1b2e061600df106d590fda3620/net/cookies/parsed_cookie.cc#L64)
-var COOKIE_PAIR = /^(([^=;]+))\s{0,256}=\s*([^\n\r\0]*)/;
-
-// Used to parse non-RFC-compliant cookies like '=abc' when given the `loose`
-// option in Cookie.parse:
-var LOOSE_COOKIE_PAIR = /^((?:=)?([^=;]*)\s{0,256}=\s*)?([^\n\r\0]*)/;
+// From Chromium // '\r', '\n' and '\0' should be treated as a terminator in
+// the "relaxed" mode, see:
+// https://github.com/ChromiumWebApps/chromium/blob/b3d3b4da8bb94c1b2e061600df106d590fda3620/net/cookies/parsed_cookie.cc#L60
+var TERMINATORS = ['\n', '\r', '\0'];
 
 // RFC6265 S4.1.1 defines path value as 'any CHAR except CTLs or ";"'
 // Note ';' is \x3B
@@ -321,32 +310,62 @@ function defaultPath(path) {
   return path.slice(0, rightSlash);
 }
 
+function trimTerminator(str) {
+  for (var t = 0; t < TERMINATORS.length; t++) {
+    var terminatorIdx = str.indexOf(TERMINATORS[t]);
+    if (terminatorIdx !== -1) {
+      str = str.substr(0,terminatorIdx);
+    }
+  }
 
-function parse(str, options) {
-  if (!options || typeof options !== 'object') {
-    options = {};
+  return str;
+}
+
+function parseCookiePair(cookiePair, looseMode) {
+  cookiePair = trimTerminator(cookiePair);
+
+  var firstEq = cookiePair.indexOf('=');
+  if (looseMode) {
+    if (firstEq === 0) { // '=' is immediately at start
+      cookiePair = cookiePair.substr(1);
+      firstEq = cookiePair.indexOf('='); // might still need to split on '='
+    }
+  } else { // non-loose mode
+    if (firstEq <= 0) { // no '=' or is at start
+      return; // needs to have non-empty "cookie-name"
+    }
   }
-  str = str.trim();
 
-  // We use a regex to parse the "name-value-pair" part of S5.2
-  var firstSemi = str.indexOf(';'); // S5.2 step 1
-  var pairRe = options.loose ? LOOSE_COOKIE_PAIR : COOKIE_PAIR;
-  var result = pairRe.exec(firstSemi === -1 ? str : str.substr(0,firstSemi));
+  var cookieName, cookieValue;
+  if (firstEq <= 0) {
+    cookieName = "";
+    cookieValue = cookiePair.trim();
+  } else {
+    cookieName = cookiePair.substr(0, firstEq).trim();
+    cookieValue = cookiePair.substr(firstEq+1).trim();
+  }
 
-  // Rx satisfies the "the name string is empty" and "lacks a %x3D ("=")"
-  // constraints as well as trimming any whitespace.
-  if (!result) {
+  if (CONTROL_CHARS.test(cookieName) || CONTROL_CHARS.test(cookieValue)) {
     return;
   }
 
   var c = new Cookie();
-  if (result[1]) {
-    c.key = result[2].trim();
-  } else {
-    c.key = '';
+  c.key = cookieName;
+  c.value = cookieValue;
+  return c;
+}
+
+function parse(str, options) {
+  if (!options || typeof options !== 'object') {
+    options = {};
   }
-  c.value = result[3].trim();
-  if (CONTROL_CHARS.test(c.key) || CONTROL_CHARS.test(c.value)) {
+  str = str.trim();
+
+  // We use a regex to parse the "name-value-pair" part of S5.2
+  var firstSemi = str.indexOf(';'); // S5.2 step 1
+  var cookiePair = (firstSemi === -1) ? str : str.substr(0, firstSemi);
+  var c = parseCookiePair(cookiePair, !!options.loose);
+  if (!c) {
     return;
   }