More branch coverage improvements. By virtue of reorganization and a new test

2 files changed, 27 insertions, 8 deletions

diff --git a/src/cryptography/hazmat/backends/openssl/backend.py b/src/cryptography/hazmat/backends/openssl/backend.py
index e27fb6e8..af66aca1 100644
--- a/src/cryptography/hazmat/backends/openssl/backend.py
+++ b/src/cryptography/hazmat/backends/openssl/backend.py
@@ -1351,9 +1351,6 @@ class Backend(object):
 
     def _private_key_bytes(self, encoding, format, encryption_algorithm,
                            evp_pkey, cdata):
-        if not isinstance(encoding, serialization.Encoding):
-            raise TypeError("encoding must be an item from the Encoding enum")
-
         if not isinstance(format, serialization.PrivateFormat):
             raise TypeError(
                 "format must be an item from the PrivateFormat enum"
@@ -1416,6 +1413,8 @@ class Backend(object):
             elif format is serialization.PrivateFormat.PKCS8:
                 write_bio = self._lib.i2d_PKCS8PrivateKey_bio
                 key = evp_pkey
+        else:
+            raise TypeError("encoding must be an item from the Encoding enum")
 
         bio = self._create_mem_bio()
         res = write_bio(
@@ -1448,11 +1447,6 @@ class Backend(object):
         if not isinstance(encoding, serialization.Encoding):
             raise TypeError("encoding must be an item from the Encoding enum")
 
-        if not isinstance(format, serialization.PublicFormat):
-            raise TypeError(
-                "format must be an item from the PublicFormat enum"
-            )
-
         if format is serialization.PublicFormat.SubjectPublicKeyInfo:
             if encoding is serialization.Encoding.PEM:
                 write_bio = self._lib.PEM_write_bio_PUBKEY
@@ -1469,6 +1463,10 @@ class Backend(object):
                 write_bio = self._lib.i2d_RSAPublicKey_bio
 
             key = cdata
+        else:
+            raise TypeError(
+                "format must be an item from the PublicFormat enum"
+            )
 
         bio = self._create_mem_bio()
         res = write_bio(bio, key)
diff --git a/tests/hazmat/primitives/test_concatkdf.py b/tests/hazmat/primitives/test_concatkdf.py
index 27e5460e..aa568c1f 100644
--- a/tests/hazmat/primitives/test_concatkdf.py
+++ b/tests/hazmat/primitives/test_concatkdf.py
@@ -158,6 +158,27 @@ class TestConcatKDFHMAC(object):
 
         assert ckdf.derive(prk) == okm
 
+    def test_derive_explicit_salt(self, backend):
+        prk = binascii.unhexlify(
+            b"013951627c1dea63ea2d7702dd24e963eef5faac6b4af7e4"
+            b"b831cde499dff1ce45f6179f741c728aa733583b02409208"
+            b"8f0af7fce1d045edbc5790931e8d5ca79c73"
+        )
+
+        okm = binascii.unhexlify(b"64ce901db10d558661f10b6836a122a7"
+                                 b"605323ce2f39bf27eaaac8b34cf89f2f")
+
+        oinfo = binascii.unhexlify(
+            b"a1b2c3d4e55e600be5f367e0e8a465f4bf2704db00c9325c"
+            b"9fbd216d12b49160b2ae5157650f43415653696421e68e"
+        )
+
+        ckdf = ConcatKDFHMAC(
+            hashes.SHA512(), 32, b"\x00" * 128, oinfo, backend
+        )
+
+        assert ckdf.derive(prk) == okm
+
     def test_verify(self, backend):
         prk = binascii.unhexlify(
             b"013951627c1dea63ea2d7702dd24e963eef5faac6b4af7e4"