feat(KDFs): add PBKDF2 algorithm

README.md

@@ -26,6 +26,7 @@ A collection of useful cryptographic algorithms written in Typescript.
 ### [Key Derivation Functions] (KDFs)
 
 - [HKDF]
+- [PBKDF2]
 
 ## Examples
 
@@ -63,3 +64,4 @@ reviews. **USE AT YOUR OWN RISK**
 [HMAC]: https://en.wikipedia.org/wiki/HMAC
 [Key Derivation Functions]: https://en.wikipedia.org/wiki/Key_derivation_function
 [HKDF]: https://en.wikipedia.org/wiki/HKDF
+[PBKDF2]: https://en.wikipedia.org/wiki/PBKDF2

pbkdf2.ts

@@ -0,0 +1,2 @@
+export { pbkdf2 } from "./src/pbkdf2/mod.ts";
+export type { SupportedAlgorithm } from "./src/pbkdf2/mod.ts";

src/hkdf/mod.ts

@@ -28,7 +28,7 @@ export function hkdf(
     const concat = new Uint8Array(t.length + info.length + 1);
     concat.set(t);
     concat.set(info, t.length);
-    concat.set([i + 1], t.length + info.length);
+    concat[t.length + info.length] = i + 1;
     t = hmac(hash, prk, concat);
     okm.set(t, hashLen * i);
   }

src/pbkdf2/mod.ts

@@ -0,0 +1,39 @@
+import { hmac, outputSizes, SupportedAlgorithm } from "../hmac/mod.ts";
+
+export type { SupportedAlgorithm };
+
+/**
+ * PKCS #5: Password-Based Key Derivation Function 2 (PBKDF2)
+ */
+export function pbkdf2(
+  hash: SupportedAlgorithm,
+  password: Uint8Array,
+  salt: Uint8Array,
+  iterations: number,
+  keylen: number,
+): Uint8Array {
+  const dk = new Uint8Array(keylen);
+
+  const salti = new Uint8Array(salt.length + 4);
+  const saltiView = new DataView(salti.buffer);
+  salti.set(salt);
+
+  const hashLen = outputSizes[hash];
+  const len = Math.ceil(keylen / hashLen);
+
+  for (let i = 1, offset = 0; i <= len; i++, offset += hashLen) {
+    saltiView.setUint32(salt.length, i);
+
+    const t = hmac(hash, password, salti);
+    let u = t;
+
+    for (let j = 1; j < iterations; j++) {
+      u = hmac(hash, password, u);
+      for (let k = 0; k < hashLen; k++) t[k] ^= u[k];
+    }
+
+    dk.set(t, offset);
+  }
+
+  return dk;
+}

tests/pbkdf2.test.ts

@@ -0,0 +1,14 @@
+import { pbkdf2 } from "../src/pbkdf2/mod.ts";
+import { assertEquals, encodeToHex } from "../dev_deps.ts";
+
+Deno.test("PBKDF2 HMAC-SHA1", () => {
+  // https://tools.ietf.org/html/rfc6070#section-2
+  const te = new TextEncoder();
+
+  const password = te.encode("password");
+  const salt = te.encode("salt");
+
+  const dk = pbkdf2("sha1", password, salt, 1, 20);
+
+  assertEquals(encodeToHex(dk), "0c60c80f961f0e71f3a9b524af6012062fe037a6");
+});