chore: checkpoint before Python removal

vendor/ghash/tests/lib.rs

@@ -0,0 +1,26 @@
+use ghash::{
+    universal_hash::{KeyInit, UniversalHash},
+    GHash,
+};
+use hex_literal::hex;
+
+//
+// Test vectors for GHASH from RFC 8452 Appendix A
+// <https://tools.ietf.org/html/rfc8452#appendix-A>
+//
+
+const H: [u8; 16] = hex!("25629347589242761d31f826ba4b757b");
+const X_1: [u8; 16] = hex!("4f4f95668c83dfb6401762bb2d01a262");
+const X_2: [u8; 16] = hex!("d1a24ddd2721d006bbe45f20d3c9f362");
+
+/// GHASH(H, X_1, X_2)
+const GHASH_RESULT: [u8; 16] = hex!("bd9b3997046731fb96251b91f9c99d7a");
+
+#[test]
+fn ghash_test_vector() {
+    let mut ghash = GHash::new(&H.into());
+    ghash.update(&[X_1.into(), X_2.into()]);
+
+    let result = ghash.finalize();
+    assert_eq!(&GHASH_RESULT[..], result.as_slice());
+}