OAuth & SSH Keygen

base64url.js

@@ -0,0 +1,31 @@
+// adapted from https://tools.ietf.org/html/draft-ietf-jose-json-web-signature-08#appendix-C
+
+function base64urlEncode(arg) {
+    const step1 = window.btoa(arg); // Regular base64 encoder
+    const step2 = step1.split("=")[0]; // Remove any trailing '='s
+    const step3 = step2.replace(/\+/g, "-"); // 62nd char of encoding
+    const step4 = step3.replace(/\//g, "_"); // 63rd char of encoding
+    return step4;
+  }
+  
+  function base64urlDecode(s) {
+    const step1 = s.replace(/-/g, "+"); // 62nd char of encoding
+    const step2 = step1.replace(/_/g, "/"); // 63rd char of encoding
+    let step3 = step2;
+    switch (step2.length % 4) { // Pad with trailing '='s
+      case 0: // No pad chars in this case
+        break;
+      case 2: // Two pad chars
+        step3 += "==";
+        break;
+      case 3: // One pad char
+        step3 += "=";
+        break;
+      default:
+        throw new Error("Illegal base64url string!");
+    }
+    return window.atob(step3); // Regular base64 decoder
+  }
+  
+  const module = window.module || {};
+  module.exports = { base64urlDecode, base64urlEncode };