diff options
Diffstat (limited to 'lib/Crypto/PublicKey/_slowmath.py')
| -rw-r--r-- | lib/Crypto/PublicKey/_slowmath.py | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/lib/Crypto/PublicKey/_slowmath.py b/lib/Crypto/PublicKey/_slowmath.py index f28ea4c..e9f48f9 100644 --- a/lib/Crypto/PublicKey/_slowmath.py +++ b/lib/Crypto/PublicKey/_slowmath.py @@ -147,15 +147,16 @@ class _DSAKey(object): def has_private(self): return hasattr(self, 'x') - def _sign(self, m, k): # alias for _decrypt + def _sign(self, m, k, blind): # alias for _decrypt # SECURITY TODO - We _should_ be computing SHA1(m), but we don't because that's the API. if not self.has_private(): raise TypeError("No private key") if not (1L < k < self.q): raise ValueError("k is not between 2 and q-1") - inv_k = inverse(k, self.q) # Compute k**-1 mod q + inv_blind_k = inverse(blind * k, self.q) # Compute (blind * k)**-1 mod q + blind_x = self.x * blind r = pow(self.g, k, self.p) % self.q # r = (g**k mod p) mod q - s = (inv_k * (m + self.x * r)) % self.q + s = (inv_blind_k * (m * blind + blind_x * r)) % self.q return (r, s) def _verify(self, m, r, s): |