Fix python3 issues in pyelliptic:

- use dotted imports, remove unneeded shebangs
 - openssl._OpenSSL._version is of type bytes
 - use b'\x00' literal instead of chr(0) in eccblind and test_openssl
 - use // and divmod in arithmetic to fit PEP238:
   https://docs.python.org/3/whatsnew/2.2.html#pep-238-changing-the-division-operator

src/pyelliptic/arithmetic.py

@@ -16,7 +16,7 @@ def inv(a, n):
     lm, hm = 1, 0
     low, high = a % n, n
     while low > 1:
-        r = high / low
+        r = high // low
         nm, new = hm - lm * r, high - low * r
         lm, low, hm, high = nm, new, lm, low
     return lm % n
@@ -43,8 +43,8 @@ def encode(val, base, minlen=0):
     code_string = get_code_string(base)
     result = ""
     while val > 0:
-        result = code_string[val % base] + result
-        val /= base
+        val, i = divmod(val, base)
+        result = code_string[i] + result
     if len(result) < minlen:
         result = code_string[0] * (minlen - len(result)) + result
     return result
@@ -101,10 +101,11 @@ def base10_multiply(a, n):
         return G
     if n == 1:
         return a
-    if (n % 2) == 0:
-        return base10_double(base10_multiply(a, n / 2))
-    if (n % 2) == 1:
-        return base10_add(base10_double(base10_multiply(a, n / 2)), a)
+    n, m = divmod(n, 2)
+    if m == 0:
+        return base10_double(base10_multiply(a, n))
+    if m == 1:
+        return base10_add(base10_double(base10_multiply(a, n)), a)
     return None
 
 

src/pyelliptic/cipher.py

@@ -1,12 +1,10 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
 """
 Symmetric Encryption
 """
 #  Copyright (C) 2011 Yann GUIBET <yannguibet@gmail.com>
 #  See LICENSE for details.
 
-from openssl import OpenSSL
+from .openssl import OpenSSL
 
 
 # pylint: disable=redefined-builtin

src/pyelliptic/ecc.py

@@ -1,5 +1,3 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
 """
 Asymmetric cryptography using elliptic curves
 """
@@ -10,9 +8,9 @@ Asymmetric cryptography using elliptic curves
 from hashlib import sha512
 from struct import pack, unpack
 
-from cipher import Cipher
-from hash import equals, hmac_sha256
-from openssl import OpenSSL
+from .cipher import Cipher
+from .hash import equals, hmac_sha256
+from .openssl import OpenSSL
 
 
 class ECC(object):

src/pyelliptic/eccblind.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python
 """
 ECC blind signature functionality based on
 "An Efficient Blind Signature Scheme
@@ -151,7 +150,7 @@ class ECCBlind(object):  # pylint: disable=too-many-instance-attributes
                 # padding manually
                 bx = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(x))
                 OpenSSL.BN_bn2bin(x, bx)
-                out = bx.raw.rjust(l_, chr(0))
+                out = bx.raw.rjust(l_, b'\x00')
             return pack(EC, y_byte, out)
 
         finally:
@@ -181,7 +180,7 @@ class ECCBlind(object):  # pylint: disable=too-many-instance-attributes
         except AttributeError:
             o = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(bn))
             OpenSSL.BN_bn2bin(bn, o)
-            return o.raw.rjust(l_, chr(0))
+            return o.raw.rjust(l_, b'\x00')
 
     def _bn_deserialize(self, data):
         """Make a BigNum out of string"""

src/pyelliptic/hash.py

@@ -4,7 +4,7 @@ Wrappers for hash functions from OpenSSL.
 #  Copyright (C) 2011 Yann GUIBET <yannguibet@gmail.com>
 #  See LICENSE for details.
 
-from openssl import OpenSSL
+from .openssl import OpenSSL
 
 
 # For python3

src/pyelliptic/openssl.py

@@ -83,7 +83,7 @@ class _OpenSSL(object):
         """
         self._lib = ctypes.CDLL(library)
         self._version, self._hexversion, self._cflags = get_version(self._lib)
-        self._libreSSL = self._version.startswith("LibreSSL")
+        self._libreSSL = self._version.startswith(b"LibreSSL")
 
         self.pointer = ctypes.pointer
         self.c_int = ctypes.c_int

src/tests/test_openssl.py

@@ -49,6 +49,6 @@ class TestOpenSSL(unittest.TestCase):
             c = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(a))
             OpenSSL.BN_bn2binpad(a, b, OpenSSL.BN_num_bytes(n))
             OpenSSL.BN_bn2bin(a, c)
-            if b.raw != c.raw.rjust(OpenSSL.BN_num_bytes(n), chr(0)):
+            if b.raw != c.raw.rjust(OpenSSL.BN_num_bytes(n), b'\x00'):
                 bad += 1
         self.assertEqual(bad, 0)