From 1454ff46416131f23f4645d0903a980a296d081e Mon Sep 17 00:00:00 2001
From: AJ ONeal <awesome@coolaj86.com>
Date: Tue, 3 Nov 2015 00:31:06 -0800
Subject: [PATCH] add generateTotpUri

---
 README.md        | 17 +++++++++++++++++
 authenticator.js | 12 ++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/README.md b/README.md
index 1616dfd..cb780ac 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,11 @@ var authenticator = window.Authenticator;
 authenticator.generateKey().then(function (formattedKey) {
   // "acqo ua72 d3yf a4e5 uorx ztkh j2xl 3wiz"
 
+  authenticator.generateTotpUri(formattedKey, "john.doe@email.com", "ACME Co", 'SHA1', 6, 30);
+  //
+  // otpauth://totp/ACME%20Co:john.doe@email.com?secret=ACQOUA72D3YFA4E5UORXZTKHJ2XL3WIZ&issuer=ACME%20Co&algorithm=SHA1&digits=6&period=30
+
+
   authenticator.generateToken(formattedKey).then(function (formattedToken) {
     // "957 124"
 
@@ -108,6 +113,18 @@ validates a time-based token within a +/- 30 second (90 seconds) window
 
 returns `null` on failure or an object such as `{ delta: 0 }` on success
 
+### generateTotpUri(formattedKey, accountName, issuer, algorithm, digits, period)
+
+generates an `OTPAUTH://` scheme URI for QR Code generation.
+
+**OTPAuth Scheme**
+
+* <https://github.com/google/google-authenticator/wiki/Key-Uri-Format>
+* `otpauth://totp/<<ISSUER>>:<<ACCOUNT_NAME>>?secret=<<BASE32_KEY>>&issuer=<<ISSUER>>`
+* `otpauth://totp/<<ISSUER>>:<<ACCOUNT_NAME>>?secret=<<BASE32_KEY>>&issuer=<<ISSUER>>&algorithm=<<ALGO>>&digits=<<INT>>&period=<<SECONDS>>`
+
+Note that `ISSUER` is specified twice for backwards / forwards compatibility.
+
 QR Code
 -------
 
diff --git a/authenticator.js b/authenticator.js
index b9f2c25..1512174 100644
--- a/authenticator.js
+++ b/authenticator.js
@@ -81,6 +81,18 @@ function verifyGoogleAuthToken(key, token) {
 Authenticator.generateKey = generateGoogleAuthKey;
 Authenticator.generateToken = generateGoogleAuthToken;
 Authenticator.verifyToken = verifyGoogleAuthToken;
+Authenticator.generateTotpUri = function (secret, accountName, issuer, algo, digits, period) {
+  // Full OTPAUTH URI spec as explained at
+  // https://github.com/google/google-authenticator/wiki/Key-Uri-Format
+  return 'otpauth://totp/'
+    + encodeURI(issuer || '') + ':' + encodeURI(accountName || '')
+    + '?secret=' + secret.replace(/[\s\.\_\-]+/g, '').toUpperCase()
+    + '&issuer=' + encodeURIComponent(issuer || '')
+    + '&algorithm=' + (algo || 'SHA1')
+    + '&digits=' + (digits || 6)
+    + '&period=' + (period || 30)
+    ;
+};
 
 }(
   'undefined' !== typeof window ? (window.Authenticator = {}) : module.exports