dls: add password hash function

src/dls/store.rs

@@ -0,0 +1,17 @@
+pub fn hash_password(salt: &[u8], passphrase: &str) -> argon2::Result<[u8; 32]> {
+    let hash = argon2::hash_raw(
+        passphrase.as_bytes(),
+        salt,
+        &argon2::Config {
+            variant: argon2::Variant::Argon2id,
+            hash_length: 32,
+            time_cost: 1,
+            mem_cost: 65536,
+            thread_mode: argon2::ThreadMode::Parallel,
+            lanes: 4,
+            ..Default::default()
+        },
+    )?;
+
+    unsafe { Ok(hash.try_into().unwrap_unchecked()) }
+}