Allow '0' as a valid header value, for content-length

Also add test to prevent regressions on this bug

Fixes #39

lib/signer.js

@@ -141,7 +141,7 @@ module.exports = {
 
       if (h !== 'request-line') {
         var value = request.getHeader(h);
-        if (!value) {
+        if (value === undefined || value === '') {
           throw new MissingHeaderError(h + ' was not in the request');
         }
         stringToSign += h + ': ' + value;

test/header.test.js

@@ -0,0 +1,99 @@
+// Copyright 2015 Joyent, Inc.  All rights reserved.
+
+var crypto = require('crypto');
+var fs = require('fs');
+var http = require('http');
+
+var test = require('tap').test;
+var uuid = require('node-uuid');
+
+var httpSignature = require('../lib/index');
+
+
+
+///--- Globals
+
+var hmacKey = null;
+var httpOptions = null;
+var rsaPrivate = null;
+var signOptions = null;
+var server = null;
+var socket = null;
+
+
+
+///--- Tests
+
+
+test('setup', function(t) {
+  rsaPrivate = fs.readFileSync(__dirname + '/rsa_private.pem', 'ascii');
+  t.ok(rsaPrivate);
+
+  socket = '/tmp/.' + uuid();
+
+  server = http.createServer(function(req, res) {
+    res.writeHead(200);
+    res.end();
+  });
+
+  server.listen(socket, function() {
+    hmacKey = uuid();
+    httpOptions = {
+      socketPath: socket,
+      path: '/',
+      method: 'HEAD',
+      headers: {
+        'content-length': '0',
+        'x-foo': 'false'
+      }
+    };
+
+    signOptions = {
+      key: rsaPrivate,
+      keyId: 'unitTest',
+    };
+
+    t.end();
+  });
+});
+
+
+
+test('header with 0 value', function(t) {
+  var req = http.request(httpOptions, function(res) {
+    t.end();
+  });
+  var opts = {
+    keyId: 'unit',
+    key: rsaPrivate,
+    headers: ['date', 'request-line', 'content-length']
+  };
+
+  t.ok(httpSignature.sign(req, opts));
+  t.ok(req.getHeader('Authorization'));
+  console.log('> ' + req.getHeader('Authorization'));
+  req.end();
+});
+
+test('header with boolean-mungable value', function(t) {
+  var req = http.request(httpOptions, function(res) {
+    t.end();
+  });
+  var opts = {
+    keyId: 'unit',
+    key: rsaPrivate,
+    headers: ['date', 'x-foo']
+  };
+
+  t.ok(httpSignature.sign(req, opts));
+  t.ok(req.getHeader('Authorization'));
+  console.log('> ' + req.getHeader('Authorization'));
+  req.end();
+});
+
+test('tear down', function(t) {
+  server.on('close', function() {
+    t.end();
+  });
+  server.close();
+});