Add token generation

lib/Token/base32.ts

@@ -0,0 +1,67 @@
+export default class Base32 {
+  static charmap: any =     null;
+  static alphabet: string = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
+
+  static encode(data: any[]): string {
+    let encoded: string = '';
+    let shift: number = 3;
+    let carry: number = 0;
+    let symbol: number;
+    let byte: number;
+
+    for (let i = 0; i < data.length; i++) {
+      byte = data[i];
+      symbol = carry | (byte >> shift);
+      encoded += Base32.alphabet[symbol & 0x1f];
+
+      if (shift > 5) {
+        shift -= 5;
+        symbol = byte >> shift;
+        encoded += Base32.alphabet[symbol & 0x1f];
+      }
+
+      shift = 5 - shift;
+      carry = byte << shift;
+      shift = 8 - shift;
+    }
+
+    if (shift !== 3) encoded += Base32.alphabet[carry & 0x1f];
+    return encoded;
+  }
+
+  static decode(data: string): Buffer | void {
+    Base32._charmap();
+    let shift: number = 8;
+    let carry: number = 0;
+    const chunks: number[] = [];
+
+    for (const char of data.toUpperCase().split('')) {
+      if (char === '') return;
+      const symbol: number = Base32.charmap[char] & 0xff;
+
+      shift -= 5;
+      if (shift > 0) carry |= symbol << shift;
+      else if (shift < 0) {
+        chunks.push(carry | (symbol >> -shift));
+        shift += 8;
+        carry = (symbol << shift) & 0xff;
+      } else {
+        chunks.push(carry | symbol);
+        shift = 8;
+        carry = 0;
+      }
+    }
+
+    if (shift !== 8 && carry !== 0) chunks.push(carry);
+    return Buffer.from(chunks);
+  }
+
+  private static _charmap() {
+    if (!Base32.charmap) {
+      const mappings: object = { 0: 14, 1: 8 };
+      const alphabet: string[] = Base32.alphabet.split('');
+      for (const i in alphabet) if (!(alphabet[i] in mappings)) mappings[alphabet[i]] = i;
+      Base32.charmap = mappings;
+    }
+  }
+}