Start with isomorphic sha512 wrapper

lib/crypto.browser.js

@@ -0,0 +1,4 @@
+/**
+ * Browser version of the crypto for Bitmessage JS implementation.
+ * @module bitmessage/lib/crypto.browser
+ */

lib/crypto.js

@@ -0,0 +1,16 @@
+/**
+ * Node.js version of the crypto for Bitmessage JS implementation.
+ * Wrap all crypto functions with promises because WebCryptoAPI uses it
+ * throughout.
+ * @module bitmessage/lib/crypto
+ */
+
+"use strict";
+
+var crypto = require("crypto");
+
+exports.sha512 = function(buf) {
+  var hash = crypto.createHash("sha512");
+  hash.update(buf);
+  return Promise.resolve(hash.digest());
+};

package.json

@@ -2,7 +2,10 @@
   "name": "bitmessage",
   "version": "0.0.0",
   "description": "JavaScript Bitmessage library",
-  "main": "index.js",
+  "main": "./lib/index",
+  "browser": {
+    "./lib/crypto": "./lib/crypto.browser"
+  },
   "scripts": {
     "test": "mocha && jshint ."
   },
@@ -24,6 +27,7 @@
   "homepage": "https://github.com/nekogrid/bitmessage",
   "devDependencies": {
     "chai": "*",
+    "es6-promise": "^2.0.1",
     "jshint": "*",
     "mocha": "*"
   }

test.js

@@ -0,0 +1,13 @@
+var expect = require("chai").expect;
+
+require("es6-promise").polyfill();
+var crypto = require("./lib/crypto");
+
+describe("crypto", function() {
+  it("should calculate sha512 hash for both node and browserify", function(done) {
+    crypto.sha512(new Buffer("test")).then(function(res) {
+      expect(res.toString("hex")).to.equal("ee26b0dd4af7e749aa1a8ee3c10ae9923f618980772e473f8819a5d4940e0db27ac185f8a0e1d5f84f88bc887fd67b143732c304cc5fa9ad8e6f57f50028a8ff");
+      done();
+    });
+  });
+});