Simplify OAEP and PSS

Makes things a little bit more like similar APIs.

* Hash type is now set in constructor.
* MGF is set automtically or manually with `set_mgf()`
* Label defaults to empty

Author: LinuxJedi

tests/test_ciphers.py

@@ -333,6 +333,14 @@ def test_chacha_enc_dec(chacha_obj):
     def rsa_private(vectors):
         return RsaPrivate(vectors[RsaPrivate].key)
 
+    @pytest.fixture
+    def rsa_private_oaep(vectors):
+        return RsaPrivate(vectors[RsaPrivate].key, hash_type=HASH_TYPE_SHA)
+
+    @pytest.fixture
+    def rsa_private_pss(vectors):
+        return RsaPrivate(vectors[RsaPrivate].key, hash_type=HASH_TYPE_SHA256)
+
     @pytest.fixture
     def rsa_private_pkcs8(vectors):
         return RsaPrivate(vectors[RsaPrivate].pkcs8_key)
@@ -341,6 +349,14 @@ def rsa_private_pkcs8(vectors):
     def rsa_public(vectors):
         return RsaPublic(vectors[RsaPublic].key)
 
+    @pytest.fixture
+    def rsa_public_oaep(vectors):
+        return RsaPublic(vectors[RsaPublic].key, hash_type=HASH_TYPE_SHA)
+
+    @pytest.fixture
+    def rsa_public_pss(vectors):
+        return RsaPublic(vectors[RsaPublic].key, hash_type=HASH_TYPE_SHA256)
+
     @pytest.fixture
     def rsa_private_pem(vectors):
         with open(vectors[RsaPrivate].pem, "rb") as f:
@@ -382,21 +398,21 @@ def test_rsa_encrypt_decrypt(rsa_private, rsa_public):
         assert 1024 / 8 == len(ciphertext) == rsa_private.output_size
         assert plaintext == rsa_private.decrypt(ciphertext)
 
-    def test_rsa_encrypt_decrypt_pad_oaep(rsa_private, rsa_public):
+    def test_rsa_encrypt_decrypt_pad_oaep(rsa_private_oaep, rsa_public_oaep):
         plaintext = t2b("Everyone gets Friday off.")
 
         # normal usage, encrypt with public, decrypt with private
-        ciphertext = rsa_public.encrypt_oaep(plaintext, HASH_TYPE_SHA, MGF1SHA1, "")
+        ciphertext = rsa_public_oaep.encrypt_oaep(plaintext)
 
-        assert 1024 / 8 == len(ciphertext) == rsa_public.output_size
-        assert plaintext == rsa_private.decrypt_oaep(ciphertext, HASH_TYPE_SHA, MGF1SHA1, "")
+        assert 1024 / 8 == len(ciphertext) == rsa_public_oaep.output_size
+        assert plaintext == rsa_private_oaep.decrypt_oaep(ciphertext)
 
         # private object holds both private and public info, so it can also encrypt
         # using the known public key.
-        ciphertext = rsa_private.encrypt_oaep(plaintext, HASH_TYPE_SHA, MGF1SHA1, "")
+        ciphertext = rsa_private_oaep.encrypt_oaep(plaintext)
 
-        assert 1024 / 8 == len(ciphertext) == rsa_private.output_size
-        assert plaintext == rsa_private.decrypt_oaep(ciphertext, HASH_TYPE_SHA, MGF1SHA1, "")
+        assert 1024 / 8 == len(ciphertext) == rsa_private_oaep.output_size
+        assert plaintext == rsa_private_oaep.decrypt_oaep(ciphertext)
 
 
     def test_rsa_pkcs8_encrypt_decrypt(rsa_private_pkcs8, rsa_public):
@@ -433,21 +449,21 @@ def test_rsa_sign_verify(rsa_private, rsa_public):
         assert plaintext == rsa_private.verify(signature)
 
     if _lib.RSA_PSS_ENABLED:
-        def test_rsa_pss_sign_verify(rsa_private, rsa_public):
+        def test_rsa_pss_sign_verify(rsa_private_pss, rsa_public_pss):
             plaintext = t2b("Everyone gets Friday off yippee.")
 
             # normal usage, sign with private, verify with public
-            signature = rsa_private.sign_pss(plaintext, HASH_TYPE_SHA256, MGF1SHA256)
+            signature = rsa_private_pss.sign_pss(plaintext)
 
-            assert 1024 / 8 == len(signature) == rsa_private.output_size
-            assert 0 == rsa_public.verify_pss(plaintext, signature, HASH_TYPE_SHA256, MGF1SHA256)
+            assert 1024 / 8 == len(signature) == rsa_private_pss.output_size
+            assert 0 == rsa_public_pss.verify_pss(plaintext, signature)
 
             # private object holds both private and public info, so it can also verify
             # using the known public key.
-            signature = rsa_private.sign_pss(plaintext, HASH_TYPE_SHA256, MGF1SHA256)
+            signature = rsa_private_pss.sign_pss(plaintext)
 
-            assert 1024 / 8 == len(signature) == rsa_private.output_size
-            assert 0 == rsa_private.verify_pss(plaintext, signature, HASH_TYPE_SHA256, MGF1SHA256)
+            assert 1024 / 8 == len(signature) == rsa_private_pss.output_size
+            assert 0 == rsa_private_pss.verify_pss(plaintext, signature)
 
     def test_rsa_sign_verify_pem(rsa_private_pem, rsa_public_pem):
         plaintext = t2b("Everyone gets Friday off.")

wolfcrypt/ciphers.py

@@ -452,6 +452,8 @@ def _decrypt(self, destination, source):
 if _lib.RSA_ENABLED:
     class _Rsa(object):  # pylint: disable=too-few-public-methods
         RSA_MIN_PAD_SIZE = 11
+        _mgf = None
+        _hash_type = None
 
         def __init__(self):
             self.native_object = _ffi.new("RsaKey *")
@@ -473,11 +475,30 @@ def __del__(self):
             if self.native_object:
                 self._delete(self.native_object)
 
+        def set_mgf(self, mgf):
+            self._mgf = mgf
+
+        def _get_mgf(self):
+            if self._hash_type == _lib.WC_HASH_TYPE_SHA:
+                self._mgf = _lib.WC_MGF1SHA1
+            elif self._hash_type == _lib.WC_HASH_TYPE_SHA224:
+                self._mgf = _lib.WC_MGF1SHA224
+            elif self._hash_type == _lib.WC_HASH_TYPE_SHA256:
+                self._mgf = _lib.WC_MGF1SHA256
+            elif self._hash_type == _lib.WC_HASH_TYPE_SHA384:
+                self._mgf = _lib.WC_MGF1SHA384
+            elif self._hash_type == _lib.WC_HASH_TYPE_SHA512:
+                self._mgf = _lib.WC_MGF1SHA512
+            else:
+                self._mgf = _lib.WC_MGF1NONE
+
+
 
     class RsaPublic(_Rsa):
-        def __init__(self, key=None):
+        def __init__(self, key=None, hash_type=None):
             if key != None:
                 key = t2b(key)
+            self._hash_type = hash_type
 
             _Rsa.__init__(self)
 
@@ -524,17 +545,18 @@ def encrypt(self, plaintext):
 
             return _ffi.buffer(ciphertext)[:]
 
-        def encrypt_oaep(self, plaintext, hash_type, mgf, label):
+        def encrypt_oaep(self, plaintext, label=""):
             plaintext = t2b(plaintext)
             label = t2b(label)
             ciphertext = _ffi.new("byte[%d]" % self.output_size)
-
+            if self._mgf is None:
+                self._get_mgf()
             ret = _lib.wc_RsaPublicEncrypt_ex(plaintext, len(plaintext),
                                               ciphertext, self.output_size,
                                               self.native_object,
                                               self._random.native_object,
-                                              _lib.WC_RSA_OAEP_PAD, hash_type,
-                                              mgf, label, len(label))
+                                              _lib.WC_RSA_OAEP_PAD, self._hash_type,
+                                              self._mgf, label, len(label))
 
             if ret != self.output_size:  # pragma: no cover
                 raise WolfCryptError("Encryption error (%d)" % ret)
@@ -563,7 +585,7 @@ def verify(self, signature):
             return _ffi.buffer(plaintext, ret)[:]
 
         if _lib.RSA_PSS_ENABLED:
-            def verify_pss(self, plaintext, signature, hash_type, mgf):
+            def verify_pss(self, plaintext, signature):
                 """
                 Verifies **signature**, using the public key data in the
                 object. The signature's length must be equal to:
@@ -574,17 +596,19 @@ def verify_pss(self, plaintext, signature, hash_type, mgf):
                 """
                 plaintext = t2b(plaintext)
                 signature = t2b(signature)
+                if self._mgf is None:
+                    self._get_mgf()
                 verify = _ffi.new("byte[%d]" % self.output_size)
 
                 ret = _lib.wc_RsaPSS_Verify(signature, len(signature),
                                             verify, self.output_size,
-                                            hash_type, mgf,
+                                            self._hash_type, self._mgf,
                                             self.native_object)
 
                 if ret < 0:  # pragma: no cover
                     raise WolfCryptError("Verify error (%d)" % ret)
                 ret = _lib.wc_RsaPSS_CheckPadding(plaintext, len(plaintext),
-                                                  verify, ret, hash_type)
+                                                  verify, ret, self._hash_type)
 
                 return ret
 
@@ -613,10 +637,10 @@ def make_key(cls, size, rng=Random()):
 
                 return rsa
 
-        def __init__(self, key = None):  # pylint: disable=super-init-not-called
+        def __init__(self, key=None, hash_type=None):  # pylint: disable=super-init-not-called
 
             _Rsa.__init__(self)  # pylint: disable=non-parent-init-called
-
+            self._hash_type = hash_type
             idx = _ffi.new("word32*")
             idx[0] = 0
 
@@ -692,7 +716,7 @@ def decrypt(self, ciphertext):
 
             return _ffi.buffer(plaintext, ret)[:]
 
-        def decrypt_oaep(self, ciphertext, hash_type, mgf, label):
+        def decrypt_oaep(self, ciphertext, label=""):
             """
             Decrypts **ciphertext**, using the private key data in the
             object. The ciphertext's length must be equal to:
@@ -704,11 +728,13 @@ def decrypt_oaep(self, ciphertext, hash_type, mgf, label):
             ciphertext = t2b(ciphertext)
             label = t2b(label)
             plaintext = _ffi.new("byte[%d]" % self.output_size)
+            if self._mgf is None:
+                self._get_mgf()
             ret = _lib.wc_RsaPrivateDecrypt_ex(ciphertext, len(ciphertext),
                                                plaintext, self.output_size,
                                                self.native_object,
-                                               _lib.WC_RSA_OAEP_PAD, hash_type,
-                                               mgf, label, len(label))
+                                               _lib.WC_RSA_OAEP_PAD, self._hash_type,
+                                               self._mgf, label, len(label))
 
             if ret < 0:  # pragma: no cover
                 raise WolfCryptError("Decryption error (%d)" % ret)
@@ -738,7 +764,7 @@ def sign(self, plaintext):
             return _ffi.buffer(signature, self.output_size)[:]
 
         if _lib.RSA_PSS_ENABLED:
-            def sign_pss(self, plaintext, hash_type, mgf):
+            def sign_pss(self, plaintext):
                 """
                 Signs **plaintext**, using the private key data in the object.
                 The plaintext's length must not be greater than:
@@ -749,10 +775,11 @@ def sign_pss(self, plaintext, hash_type, mgf):
                 """
                 plaintext = t2b(plaintext)
                 signature = _ffi.new("byte[%d]" % self.output_size)
-
+                if self._mgf is None:
+                    self._get_mgf()
                 ret = _lib.wc_RsaPSS_Sign(plaintext, len(plaintext),
                                           signature, self.output_size,
-                                          hash_type, mgf,
+                                          self._hash_type, self._mgf,
                                           self.native_object,
                                           self._random.native_object)