f4jumble: Use BLAKE2b hashes for the long test vectors.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

f4jumble.py

@@ -91,7 +91,9 @@ def main():
         return bytes(ret)
     rand = Rand(randbytes)
 
-    test_vectors = []
+    plain_test_vectors = []
+    hashed_test_vectors = []
+
     # Generate test vectors with various lengths:
     for l_M in [
         MIN_l_M,
@@ -102,19 +104,30 @@ def main():
         3*l_H + 1,
         257*l_H,
         257*l_H + 1,
-        (rand.u32() % (MAX_l_M - MIN_l_M)) + MIN_l_M,
-        MAX_l_M,
     ]:
         M = rand.b(l_M)
         jumbled = f4jumble(M)
         assert len(jumbled) == len(M)
         assert f4jumble_inv(jumbled) == M
-        test_vectors.append(M)
 
-    test_vectors = [{
-        'normal': M,
-        'jumbled': f4jumble(M),
-    } for M in test_vectors]
+        plain_test_vectors.append({
+            'normal': M,
+            'jumbled': jumbled,
+        })
+
+    for l_M in [
+        (rand.u32() % (MAX_l_M - MIN_l_M)) + MIN_l_M,
+        MAX_l_M,
+    ]:
+        M = bytes([i & 0xFF for i in range(l_M)])
+        jumbled = f4jumble(M)
+        assert len(jumbled) == len(M)
+        assert f4jumble_inv(jumbled) == M
+
+        hashed_test_vectors.append({
+            'length': l_M,
+            'jumbled_hash': blake2b(jumbled).digest()
+        })
 
     render_tv(
         args,
@@ -123,7 +136,17 @@ def main():
             ('normal', 'Vec<u8>'),
             ('jumbled', 'Vec<u8>'),
         ),
-        test_vectors,
+        plain_test_vectors,
+    )
+    print()
+    render_tv(
+        args,
+        'f4jumble',
+        (
+            ('length', 'usize'),
+            ('jumbled_hash', 'Vec<u8>'),
+        ),
+        hashed_test_vectors,
     )