http: add checkIsHttpToken check for header fields

Ref: https://github.com/nodejs/node-convergence-archive/issues/13

This adds a new check for header and trailer fields names and method
names to ensure that they conform to the HTTP token rule. If they do
not, a `TypeError` is thrown.

Previously this had an additional `strictMode` option that has been
removed in favor of making the strict check the default (and only)
behavior.

Doc and test case are included.

On the client-side
```javascript
var http = require('http');
var url = require('url');
var p = url.parse('http://localhost:8888');
p.headers = {'testing 123': 123};
http.client(p, function(res) { }); // throws
```

On the server-side
```javascript
var http = require('http');
var server = http.createServer(function(req,res) {
  res.setHeader('testing 123', 123); // throws
  res.end('...');
});
```

Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Trevor Norris <trevnorris@nodejs.org>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Rod Vagg <rod@vagg.org>
PR-URL: https://github.com/nodejs/node/pull/2526

doc/api/http.markdown

@@ -364,6 +364,9 @@ or
 
     response.setHeader("Set-Cookie", ["type=ninja", "language=javascript"]);
 
+Attempting to set a header field name that contains invalid characters will
+result in a `TypeError` being thrown.
+
 ### response.headersSent
 
 Boolean (read-only). True if headers were sent, false otherwise.
@@ -439,6 +442,8 @@ emit trailers, with a list of the header fields in its value. E.g.,
     response.addTrailers({'Content-MD5': "7895bf4b8828b55ceaf47747b4bca667"});
     response.end();
 
+Attempting to set a trailer field name that contains invalid characters will
+result in a `TypeError` being thrown.
 
 ### response.end([data][, encoding][, callback])
 

lib/_http_client.js

@@ -67,6 +67,9 @@ function ClientRequest(options, cb) {
   self.socketPath = options.socketPath;
 
   var method = self.method = (options.method || 'GET').toUpperCase();
+  if (!common._checkIsHttpToken(method)) {
+    throw new TypeError('Method must be a valid HTTP token');
+  }
   self.path = options.path || '/';
   if (cb) {
     self.once('response', cb);

lib/_http_common.js

@@ -195,3 +195,13 @@ function httpSocketSetup(socket) {
   socket.on('drain', ondrain);
 }
 exports.httpSocketSetup = httpSocketSetup;
+
+/**
+ * Verifies that the given val is a valid HTTP token
+ * per the rules defined in RFC 7230
+ **/
+const token = /^[a-zA-Z0-9_!#$%&'*+.^`|~-]+$/;
+function checkIsHttpToken(val) {
+  return typeof val === 'string' && token.test(val);
+}
+exports._checkIsHttpToken = checkIsHttpToken;

lib/_http_outgoing.js

@@ -295,6 +295,10 @@ OutgoingMessage.prototype._storeHeader = function(firstLine, headers) {
 };
 
 function storeHeader(self, state, field, value) {
+  if (!common._checkIsHttpToken(field)) {
+    throw new TypeError(
+      'Header name must be a valid HTTP Token ["' + field + '"]');
+  }
   value = escapeHeaderValue(value);
   state.messageHeader += field + ': ' + value + CRLF;
 
@@ -323,6 +327,9 @@ function storeHeader(self, state, field, value) {
 
 
 OutgoingMessage.prototype.setHeader = function(name, value) {
+  if (!common._checkIsHttpToken(name))
+    throw new TypeError(
+      'Header name must be a valid HTTP Token ["' + name + '"]');
   if (typeof name !== 'string')
     throw new TypeError('`name` should be a string in setHeader(name, value).');
   if (value === undefined)
@@ -498,7 +505,10 @@ OutgoingMessage.prototype.addTrailers = function(headers) {
       field = key;
       value = headers[key];
     }
-
+    if (!common._checkIsHttpToken(field)) {
+      throw new TypeError(
+        'Trailer name must be a valid HTTP Token ["' + field + '"]');
+    }
     this._trailer += field + ': ' + escapeHeaderValue(value) + CRLF;
   }
 };

test/parallel/test-http-invalidheaderfield.js

@@ -0,0 +1,56 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const EventEmitter = require('events');
+const http = require('http');
+
+const ee = new EventEmitter();
+var count = 3;
+
+const server = http.createServer(function(req, res) {
+  assert.doesNotThrow(function() {
+    res.setHeader('testing_123', 123);
+  });
+  assert.throws(function() {
+    res.setHeader('testing 123', 123);
+  }, TypeError);
+  res.end('');
+});
+server.listen(common.PORT, function() {
+
+  http.get({port: common.PORT}, function() {
+    ee.emit('done');
+  });
+
+  assert.throws(
+    function() {
+      var options = {
+        port: common.PORT,
+        headers: {'testing 123': 123}
+      };
+      http.get(options, function() {});
+    },
+    function(err) {
+      ee.emit('done');
+      if (err instanceof TypeError) return true;
+    }
+  );
+
+  assert.doesNotThrow(
+    function() {
+      var options = {
+        port: common.PORT,
+        headers: {'testing_123': 123}
+      };
+      http.get(options, function() {
+        ee.emit('done');
+      });
+    }, TypeError
+  );
+});
+
+ee.on('done', function() {
+  if (--count === 0) {
+    server.close();
+  }
+});