Merge pull request #87 from JeremiahM37/fenrir-fixes

Fix Fenrir findings in SHA3, RSA-PSS, FFI feature detection, and ChaCha

Author: dgarske

scripts/build_ffi.py

@@ -375,7 +375,7 @@ def get_features(local_wolfssl, features):
     features["WC_RNG_SEED_CB"] = 1 if '#define WC_RNG_SEED_CB' in defines else 0
     features["AESGCM_STREAM"] = 1 if '#define WOLFSSL_AESGCM_STREAM' in defines else 0
     features["RSA_PSS"] = 1 if '#define WC_RSA_PSS' in defines else 0
-    features["CHACHA20_POLY1305"] = 1 if '#define HAVE_CHACHA' and '#define HAVE_POLY1305' in defines else 0
+    features["CHACHA20_POLY1305"] = 1 if ('#define HAVE_CHACHA' in defines and '#define HAVE_POLY1305' in defines) else 0
     features["ML_DSA"] = 1 if '#define HAVE_DILITHIUM'  in defines else 0
     features["ML_KEM"] = 1 if '#define WOLFSSL_HAVE_MLKEM'  in defines else 0
     features["HKDF"] = 1 if "#define HAVE_HKDF" in defines else 0
@@ -386,7 +386,7 @@ def get_features(local_wolfssl, features):
             raise RuntimeError(e)
 
         features["FIPS"] = 1
-        version_match = re.search(r'#define HAVE_FIPS_VERSION\s+(\d+)', defines)
+        version_match = re.search(r'#define HAVE_FIPS_VERSION\s+(\d+)', '\n'.join(defines))
         if version_match is not None:
             features["FIPS_VERSION"] = int(version_match.group(1))
         else:
@@ -756,6 +756,8 @@ def build_ffi(local_wolfssl, features):
         int wc_RsaPrivateDecrypt_ex(const byte* in, word32 inLen,
                    byte* out, word32 outLen, RsaKey* key, int type,
                    enum wc_HashType hash, int mgf, byte* label, word32 labelSz);
+        int wc_RsaSSL_Sign(const byte*, word32, byte*, word32, RsaKey*, WC_RNG*);
+        int wc_RsaSSL_Verify(const byte*, word32, byte*, word32, RsaKey*);
         """
 
         if features["RSA_PSS"]:
@@ -766,8 +768,6 @@ def build_ffi(local_wolfssl, features):
                                    enum wc_HashType hash, int mgf, RsaKey* key);
             int wc_RsaPSS_CheckPadding(const byte* in, word32 inSz, byte* sig,
                                    word32 sigSz, enum wc_HashType hashType);
-            int wc_RsaSSL_Sign(const byte*, word32, byte*, word32, RsaKey*, WC_RNG*);
-            int wc_RsaSSL_Verify(const byte*, word32, byte*, word32, RsaKey*);
             """
 
         if features["RSA_BLINDING"]:

tests/test_ciphers.py

@@ -456,14 +456,14 @@ def test_rsa_pss_sign_verify(rsa_private_pss, rsa_public_pss):
             signature = rsa_private_pss.sign_pss(plaintext)
 
             assert 1024 / 8 == len(signature) == rsa_private_pss.output_size
-            assert 0 == rsa_public_pss.verify_pss(plaintext, signature)
+            assert rsa_public_pss.verify_pss(plaintext, signature) is True
 
             # private object holds both private and public info, so it can also verify
             # using the known public key.
             signature = rsa_private_pss.sign_pss(plaintext)
 
             assert 1024 / 8 == len(signature) == rsa_private_pss.output_size
-            assert 0 == rsa_private_pss.verify_pss(plaintext, signature)
+            assert rsa_private_pss.verify_pss(plaintext, signature) is True
 
     def test_rsa_sign_verify_pem(rsa_private_pem, rsa_public_pem):
         plaintext = t2b("Everyone gets Friday off.")

wolfcrypt/ciphers.py

@@ -530,8 +530,13 @@ def _decrypt(self, destination, source):
             return _lib.wc_Chacha_Process(self._dec,
                                           destination, source, len(source))
 
+        _NONCE_SIZE = 12
+
         def set_iv(self, nonce, counter = 0):
             self._IV_nonce = t2b(nonce)
+            if len(self._IV_nonce) != self._NONCE_SIZE:
+                raise ValueError("nonce must be %d bytes, got %d" %
+                                 (self._NONCE_SIZE, len(self._IV_nonce)))
             self._IV_counter = counter
             self._set_key(0)
 
@@ -811,8 +816,10 @@ def verify_pss(self, plaintext, signature):
                 ret = _lib.wc_RsaPSS_CheckPadding(digest, len(digest),
                                                   verify, ret, self._hash_type)
 
-                return ret
+                if ret < 0:  # pragma: no cover
+                    raise WolfCryptError("PSS padding check error (%d)" % ret)
 
+                return ret == 0
 
 
     class RsaPrivate(RsaPublic):

wolfcrypt/hashes.py

@@ -209,14 +209,7 @@ class Sha3(_Hash):
         SHA3_384_DIGEST_SIZE = 48
         SHA3_512_DIGEST_SIZE = 64
 
-        def __init__(self):  # pylint: disable=W0231
-            self._native_object = _ffi.new(self._native_type)
-            self.digest_size = SHA3_384_DIGEST_SIZE
-            ret = self._init()
-            if ret < 0:  # pragma: no cover
-                raise WolfCryptError("Sha3 init error (%d)" % ret)
-
-        def __init__(self, string, size=SHA3_384_DIGEST_SIZE):  # pylint: disable=W0231
+        def __init__(self, string=None, size=SHA3_384_DIGEST_SIZE):  # pylint: disable=W0231
             self._native_object = _ffi.new(self._native_type)
             self.digest_size = size
             ret = self._init()
@@ -225,6 +218,15 @@ def __init__(self, string, size=SHA3_384_DIGEST_SIZE):  # pylint: disable=W0231
             if string:
                 self.update(string)
 
+        @classmethod
+        def new(cls, string=None, size=SHA3_384_DIGEST_SIZE):
+            return cls(string, size)
+
+        def copy(self):
+            c = Sha3(size=self.digest_size)
+            _ffi.memmove(c._native_object, self._native_object, self._native_size)
+            return c
+
         def _init(self):
             if (self.digest_size != Sha3.SHA3_224_DIGEST_SIZE and
                     self.digest_size != Sha3.SHA3_256_DIGEST_SIZE and