fixup! Revert to using hkdf

Author: G8XSU

src/io/vss_store.rs

@@ -240,9 +240,9 @@ fn derive_data_encryption_and_obfuscation_keys(vss_seed: &[u8; 32]) -> ([u8; 32]
 		Hmac::from_engine(engine).to_byte_array()
 	};
 
-	let prk = hkdf(vss_seed, "pseudo_random_key".as_bytes());
-	let k1 = hkdf(&prk, "data_encryption_key".as_bytes());
-	let k2 = hkdf(&prk, &[&k1[..], "obfuscation_key".as_bytes()].concat());
+	let prk = hkdf(vss_seed, b"pseudo_random_key");
+	let k1 = hkdf(&prk, b"data_encryption_key");
+	let k2 = hkdf(&prk, &[&k1[..], b"obfuscation_key"].concat());
 	(k1, k2)
 }