Add react-native support

.gitignore

@@ -1,4 +1,5 @@
 .DS_Store
+webcrypto-shim.mjs
 
 # Logs
 logs

README.md

@@ -31,7 +31,25 @@ crypto.subtle.digest(
 
 ## Compatibility
 
-See [webcrypto-shim's supported browsers](https://github.com/vibornoff/webcrypto-shim#supported-browsers)
+See [webcrypto-shim's supported browsers](https://github.com/vibornoff/webcrypto-shim#supported-browsers) for standard browser support.
+
+If you need a js-only implementation for older browsers or environments that don't have any crypto support, the [Microsoft Research library](https://www.microsoft.com/en-us/download/details.aspx?id=52439) is exposed as the `extended` version.
+
+```javascript
+const crypto = require('isomorphic-crypto/extended')
+
+/**
+ * IMPORTANT: On platforms without crypto, the
+ * js-only implementation needs another source 
+ * of entropy for operations that require
+ * random numbers (creating keys, encrypting,
+ * wrapping keys) This should NOT be Math.random()
+ */
+
+crypto.initPrng(randomArrayOf48Bytes)
+```
+
+> 
 
 ## I just want to drop in a script tag
 

browser.android.js

@@ -0,0 +1 @@
+module.exports = require('./react-native.js')

browser.ios.js

@@ -0,0 +1 @@
+module.exports = require('./react-native.js')

index.android.js

@@ -0,0 +1 @@
+module.exports = require('./react-native.js')

index.ios.js

@@ -0,0 +1 @@
+module.exports = require('./react-native.js')

main.browser.js

@@ -0,0 +1 @@
+module.exports = require('./browser')

main.js

@@ -0,0 +1 @@
+module.exports = require('./index')

package.json

@@ -2,10 +2,10 @@
   "name": "isomorphic-webcrypto",
   "version": "1.1.3",
   "description": "isomorphic webcrypto for IE11+ in 3kB",
-  "main": "index.js",
+  "main": "main.js",
   "module": "index.mjs",
   "browser": {
-    "./index.js": "browser.js",
+    "./main.js": "main.browser.js",
     "./index.mjs": "browser.mjs"
   },
   "types": "index.d.ts",
@@ -18,6 +18,21 @@
     "type": "git",
     "url": "git+https://github.com/kevlened/isomorphic-webcrypto.git"
   },
+  "files": [
+    "browser.android.js",
+    "browser.ios.js",
+    "browser.js",
+    "browser.mjs",
+    "index.android.js",
+    "index.d.ts",
+    "index.ios.js",
+    "index.js",
+    "index.mjs",
+    "main.browser.js",
+    "main.js",
+    "react-native.js",
+    "webcrypto-shim.mjs"
+  ],
   "keywords": [
     "isomorphic",
     "webcrypto",
@@ -30,6 +45,11 @@
   "homepage": "https://github.com/kevlened/isomorphic-webcrypto#readme",
   "dependencies": {
     "@trust/webcrypto": "^0.8.2",
+    "mitt": "^1.1.3",
+    "msrcrypto": "^1.4.0",
     "webcrypto-shim": "^0.1.2"
+  },
+  "peerDependencies": {
+    "react-native-securerandom": "^0.1.1"
   }
 }

react-native.js

@@ -0,0 +1,57 @@
+const generateSecureRandom = require('react-native-securerandom').generateSecureRandom
+const EventEmitter = require('mitt')
+const crypto = require('msrcrypto')
+crypto.subtle.forceSync = true
+
+const secureWatch = new EventEmitter()
+
+let secured = !crypto.initPrng
+let secureRandomError
+if (!secured) {
+  generateSecureRandom(48)
+  .then(byteArray => {
+    crypto.initPrng(Array.from(byteArray))
+    secured = true
+    secureWatch.emit('secure')
+  })
+  .catch(err => {
+    secureRandomError = err
+    secureWatch.emit('secureRandomError')
+  })
+}
+
+crypto.ensureSecure = function(cb) {
+  if (secured) return cb()
+  if (secureRandomError) return cb(secureRandomError)
+  secureWatch.on('secure', () => cb())
+  secureWatch.on('secureRandomError', () => cb(secureRandomError))
+}
+
+// wrap all methods to ensure they're secure
+const methods = [
+  'decrypt',
+  'digest',
+  'deriveKey',
+  'encrypt',
+  'exportKey',
+  'generateKey',
+  'importKey',
+  'sign',
+  'unwrapKey',
+  'verify',
+  'wrapKey'
+]
+methods.map(key => {
+  const original = crypto.subtle[key]
+  crypto.subtle[key] = function() {
+    const args = Array.from(arguments)
+    return new Promise((resolve, reject) => {
+      crypto.ensureSecure(err => {
+        if (err) return reject(err)
+        resolve(original.apply(crypto.subtle, args))
+      })
+    })
+  }
+})
+
+module.exports = crypto