feat: phc strings example

examples/phc.ts

@@ -0,0 +1,36 @@
+import { timingSafeEqual } from "https://deno.land/[email protected]/crypto/timing_safe_equal.ts";
+import { Buffer } from "node:buffer";
+import phc from "npm:@phc/format";
+import { hash } from "../mod.ts";
+
+const encoder = new TextEncoder();
+
+// Store the salt and hash, this could be done with a PHC string or just as is.
+// Using a PHC string you would use the `phc.serialize` function to encode it
+const salt1 = new Uint8Array(40);
+crypto.getRandomValues(salt1);
+const hash1 = hash(encoder.encode("example password 1"), salt1);
+
+// Serializing as PHC, this is when you would want to store it in the database
+const phc1 = phc.serialize({
+  id: "argon2id",
+  version: 19,
+  params: {
+    m: 4096,
+    t: 3,
+    p: 1,
+  },
+  salt: Buffer.from(salt1),
+  hash: Buffer.from(hash1),
+});
+
+// Deserializing the PHC string, probably directly fetched from a database in a real-life scenario
+const { salt: _salt2, hash: hash2 } = phc.deserialize(phc1);
+
+// Using timing safe equal protects against timing based attacks
+console.log(timingSafeEqual(hash1, hash2));
+
+// You would probably not compare the `hash1` variable with `hash2` as they should be identical
+// Instead you would hash the plaintext password which has been sent in with the deserialized salt
+// and compare it with the deserialized hash which you have fetched from the database and earlier
+// stored as an PHC string.