Break up hkdf_derive into hkdf_extract and hkdf_expand.

Testing each individually against all the vectors and actually
asserting about the intermediate state.

hkdf_derive is now just a helper function which copes with the
default arguments.

1 files changed, 7 insertions, 21 deletions

diff --git a/tests/utils.py b/tests/utils.py
index 5f2c6ff6..850d436f 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -196,11 +196,7 @@ def load_hash_vectors(vector_data):
 def load_hkdf_vectors(vector_data):
     vectors = []
 
-    ikm = None
-    salt = None
-    info = None
-    length = None
-    okm = None
+    ikm = salt = info = length = prk = okm = None
 
     for line in vector_data:
         line = line.strip()
@@ -211,27 +207,17 @@ def load_hkdf_vectors(vector_data):
         elif line.startswith("IKM"):
             ikm = line.split(" = ")[1].encode("ascii")
         elif line.startswith("salt"):
-            l = line.split(" =")
-            if len(l) == 1:
-                salt = b""
-            else:
-                salt = l[1].strip().encode("ascii")
+            salt = line.split(" =")[1].strip().encode("ascii")
         elif line.startswith("info"):
-            l = line.split(" =")
-            if len(l) == 1:
-                info = b""
-            else:
-                info = l[1].strip().encode("ascii")
+            info = line.split(" =")[1].strip().encode("ascii")
         elif line.startswith("L"):
             length = int(line.split(" = ")[1])
+        elif line.startswith("PRK"):
+            prk = line.split(" = ")[1].encode("ascii")
         elif line.startswith("OKM"):
             okm = line.split(" = ")[1].encode("ascii")
 
-            vectors.append((ikm, salt, info, length, okm))
-            ikm = None
-            salt = None
-            info = None
-            length = None
-            okm = None
+            vectors.append((ikm, salt, info, length, prk, okm))
+            ikm = salt = info = length = prk = okm = None
 
     return vectors