Initial code commit

Author: iFaxity

deps.ts

@@ -0,0 +1,6 @@
+// First party libraries
+export { HmacSha256 } from 'https://deno.land/[email protected]/hash/sha256.ts';
+export { HmacSha512 } from 'https://deno.land/[email protected]/hash/sha512.ts';
+export * as base64url from 'https://deno.land/[email protected]/encoding/base64url.ts';
+//export { Sha3_224, Sha3_256, Sha3_384, Sha3_512 } from 'https://deno.land/[email protected]/hash/sha3.ts';
+

mod.ts

@@ -0,0 +1,66 @@
+/*!
+ * keygrip
+ * Copyright(c) 2011-2014 Jed Schmidt
+ * Copyright(c) 2020 Christian Norrman
+ * MIT Licensed
+ */
+
+import { HmacSha256, HmacSha512 } from './deps.ts';
+
+const SANITIZE_REGEXP = /\/|\+|=/g;
+const SANITIZE_REPLACERS = {
+  "/": "_",
+  "+": "-",
+  "=": "",
+} as Record<string, string>;
+
+export enum Algorithm {
+  SHA256 = 'sha256',
+  SHA512 = 'sha512',
+}
+
+export class Keygrip {
+  #keys: string[];
+  #decoder: TextDecoder;
+  #algo: Algorithm;
+
+  constructor(keys: string[], algo: Algorithm=Algorithm.SHA256, enc: string='base64') {
+    if (!keys || !keys.length) {
+      throw new Error('Keys must be provided.');
+    } else if (algo != 'sha256' && algo != 'sha512') {
+      throw new Error('Algorithm not found');
+    }
+
+    this.#keys = keys;
+    this.#algo = algo;
+    this.#decoder = new TextDecoder(enc);
+  }
+
+  sign(data: string, key?: string): string {
+    let buffer: ArrayBuffer;
+    key = key ?? this.#keys[0];
+
+    if (this.#algo == 'sha256') {
+      const hash = new HmacSha256(key);
+      buffer = hash.update(data).arrayBuffer();
+    } else if (this.#algo == 'sha512') {
+      const hash = new HmacSha512(key);
+      buffer = hash.update(data).arrayBuffer();
+    } else {
+      // Required for typescript
+      throw new Error('Algorithm invalid');
+    }
+
+    return this.#decoder
+      .decode(buffer)
+      .replace(SANITIZE_REGEXP, s => SANITIZE_REPLACERS[s]);
+  }
+
+  verify(data: string, digest: string): boolean {
+    return this.index(data, digest) != -1;
+  }
+
+  index(data: string, digest: string): number {
+    return this.#keys.findIndex(key => digest === this.sign(data, key));
+  }
+}