bug: Allow sign and verify to use different hashes than sha256

closes yann2192#52

CHANGES.txt

@@ -1,3 +1,8 @@
+v1.6.0, 2016-12-21
+------------------
+
+- allow other SHA digests (other than SHA_256)
+
 v1.5.7, 2015-08-31
 ------------------
 

pyelliptic/__init__.py

@@ -31,7 +31,7 @@
 # OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 # IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-__version__ = '1.5.7'
+__version__ = '1.6.0'
 
 __all__ = [
     'OpenSSL',

pyelliptic/ecc.py

@@ -68,10 +68,12 @@ class ECC:
     """
 
     def __init__(self, pubkey=None, privkey=None, pubkey_x=None,
-                 pubkey_y=None, raw_privkey=None, curve='sect283r1'):
+                 pubkey_y=None, raw_privkey=None, curve='sect283r1',
+                 hasher='sha256'):
         """
-        For a normal and High level use, specifie pubkey,
-        privkey (if you need) and the curve
+        For a normal and High level use, specify pubkey,
+        privkey (if you need), the curve, and the hashing method.
+
         """
         if type(curve) == str:
             self.curve = OpenSSL.get_curve(curve)
@@ -88,6 +90,14 @@ def __init__(self, pubkey=None, privkey=None, pubkey_x=None,
         else:
             self.privkey, self.pubkey_x, self.pubkey_y = self._generate()
 
+        _hashers = {
+            "sha256": OpenSSL.EVP_sha256(),
+            "sha384": OpenSSL.EVP_sha384(),
+            "sha512": OpenSSL.EVP_sha512(),
+        }
+        self.hashval = hasher
+        self.hasher = _hashers[hasher]
+
     def _set_keys(self, pubkey_x, pubkey_y, privkey):
         if self.raw_check_key(privkey, pubkey_x, pubkey_y) < 0:
             self.pubkey_x = None
@@ -414,7 +424,7 @@ def sign(self, inputb):
                 raise Exception("[OpenSSL] EC_KEY_check_key FAIL ... " + OpenSSL.get_error())
 
             OpenSSL.EVP_MD_CTX_init(md_ctx)
-            OpenSSL.EVP_DigestInit_ex(md_ctx, OpenSSL.EVP_sha256(), None)
+            OpenSSL.EVP_DigestInit_ex(md_ctx, self.hasher, None)
 
             if (OpenSSL.EVP_DigestUpdate(md_ctx, buff, size)) == 0:
                 raise Exception("[OpenSSL] EVP_DigestUpdate FAIL ... " + OpenSSL.get_error())
@@ -466,12 +476,10 @@ def verify(self, sig, inputb):
                 raise Exception("[OpenSSL] EC_KEY_set_public_key FAIL ... " + OpenSSL.get_error())
             if (OpenSSL.EC_KEY_check_key(key)) == 0:
                 raise Exception("[OpenSSL] EC_KEY_check_key FAIL ... " + OpenSSL.get_error())
-
             OpenSSL.EVP_MD_CTX_init(md_ctx)
-            OpenSSL.EVP_DigestInit_ex(md_ctx, OpenSSL.EVP_sha256(), None)
+            OpenSSL.EVP_DigestInit_ex(md_ctx, self.hasher, None)
             if (OpenSSL.EVP_DigestUpdate(md_ctx, binputb, len(inputb))) == 0:
                 raise Exception("[OpenSSL] EVP_DigestUpdate FAIL ... " + OpenSSL.get_error())
-
             OpenSSL.EVP_DigestFinal_ex(md_ctx, digest, dgst_len)
             ret = OpenSSL.ECDSA_verify(
                 0, digest, dgst_len.contents, bsig, len(sig), key)

pyelliptic/hash.py

@@ -70,6 +70,18 @@ def hmac_sha256(k, m):
     return md.raw
 
 
+def hmac_sha384(k, m):
+    """
+    Compute the key and the message with HMAC SHA384
+    """
+    key = OpenSSL.malloc(k, len(k))
+    d = OpenSSL.malloc(m, len(m))
+    md = OpenSSL.malloc(0, 64)
+    i = OpenSSL.pointer(OpenSSL.c_int(0))
+    OpenSSL.HMAC(OpenSSL.EVP_sha384(), key, len(k), d, len(m), md, i)
+    return md.raw
+
+
 def hmac_sha512(k, m):
     """
     Compute the key and the message with HMAC SHA512

pyelliptic/openssl.py

@@ -100,6 +100,10 @@ def __init__(self, library):
         self.BN_bin2bn.argtypes = [ctypes.c_void_p, ctypes.c_int,
                                    ctypes.c_void_p]
 
+        self.BN_bn2dec = self._lib.BN_bn2dec
+        self.BN_bn2dec.restype = ctypes.c_char_p
+        self.BN_bn2dec.argtypes = [ctypes.c_void_p]
+
         self.EC_GROUP_get_degree = self._lib.EC_GROUP_get_degree
         self.EC_GROUP_get_degree.restype = ctypes.c_int
         self.EC_GROUP_get_degree.argtypes = [ctypes.c_void_p]
@@ -344,6 +348,10 @@ def __init__(self, library):
         self.EVP_sha256.restype = ctypes.c_void_p
         self.EVP_sha256.argtypes = []
 
+        self.EVP_sha384 = self._lib.EVP_sha384
+        self.EVP_sha384.restype = ctypes.c_void_p
+        self.EVP_sha384.argtypes = []
+
         self.i2o_ECPublicKey = self._lib.i2o_ECPublicKey
         self.i2o_ECPublicKey.restype = ctypes.c_int
         self.i2o_ECPublicKey.argtypes = [ctypes.c_void_p, ctypes.c_void_p]

setup.py

@@ -31,9 +31,11 @@
 
 from setuptools import setup, find_packages
 
+from pyelliptic import __version__
+
 setup(
     name="pyelliptic",
-    version='1.5.7',
+    version=__version__,
     url='https://github.com/yann2192/pyelliptic',
     license='BSD',
     description=