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Diffstat (limited to 'frozen_deps/Crypto/PublicKey/_slowmath.py')
| -rw-r--r-- | frozen_deps/Crypto/PublicKey/_slowmath.py | 187 |
1 files changed, 0 insertions, 187 deletions
diff --git a/frozen_deps/Crypto/PublicKey/_slowmath.py b/frozen_deps/Crypto/PublicKey/_slowmath.py deleted file mode 100644 index c87bdd2..0000000 --- a/frozen_deps/Crypto/PublicKey/_slowmath.py +++ /dev/null @@ -1,187 +0,0 @@ -# -*- coding: utf-8 -*- -# -# PubKey/RSA/_slowmath.py : Pure Python implementation of the RSA portions of _fastmath -# -# Written in 2008 by Dwayne C. Litzenberger <dlitz@dlitz.net> -# -# =================================================================== -# The contents of this file are dedicated to the public domain. To -# the extent that dedication to the public domain is not available, -# everyone is granted a worldwide, perpetual, royalty-free, -# non-exclusive license to exercise all rights associated with the -# contents of this file for any purpose whatsoever. -# No rights are reserved. -# -# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, -# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF -# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND -# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS -# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN -# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN -# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE -# SOFTWARE. -# =================================================================== - -"""Pure Python implementation of the RSA-related portions of Crypto.PublicKey._fastmath.""" - -__revision__ = "$Id$" - -__all__ = ['rsa_construct'] - -import sys - -if sys.version_info[0] == 2 and sys.version_info[1] == 1: - from Crypto.Util.py21compat import * -from Crypto.Util.number import size, inverse, GCD - -class error(Exception): - pass - -class _RSAKey(object): - def _blind(self, m, r): - # compute r**e * m (mod n) - return m * pow(r, self.e, self.n) - - def _unblind(self, m, r): - # compute m / r (mod n) - return inverse(r, self.n) * m % self.n - - def _decrypt(self, c): - # compute c**d (mod n) - if not self.has_private(): - raise TypeError("No private key") - if (hasattr(self,'p') and hasattr(self,'q') and hasattr(self,'u')): - m1 = pow(c, self.d % (self.p-1), self.p) - m2 = pow(c, self.d % (self.q-1), self.q) - h = m2 - m1 - if (h<0): - h = h + self.q - h = h*self.u % self.q - return h*self.p+m1 - return pow(c, self.d, self.n) - - def _encrypt(self, m): - # compute m**d (mod n) - return pow(m, self.e, self.n) - - def _sign(self, m): # alias for _decrypt - if not self.has_private(): - raise TypeError("No private key") - return self._decrypt(m) - - def _verify(self, m, sig): - return self._encrypt(sig) == m - - def has_private(self): - return hasattr(self, 'd') - - def size(self): - """Return the maximum number of bits that can be encrypted""" - return size(self.n) - 1 - -def rsa_construct(n, e, d=None, p=None, q=None, u=None): - """Construct an RSAKey object""" - assert isinstance(n, int) - assert isinstance(e, int) - assert isinstance(d, (int, type(None))) - assert isinstance(p, (int, type(None))) - assert isinstance(q, (int, type(None))) - assert isinstance(u, (int, type(None))) - obj = _RSAKey() - obj.n = n - obj.e = e - if d is None: - return obj - obj.d = d - if p is not None and q is not None: - obj.p = p - obj.q = q - else: - # Compute factors p and q from the private exponent d. - # We assume that n has no more than two factors. - # See 8.2.2(i) in Handbook of Applied Cryptography. - ktot = d*e-1 - # The quantity d*e-1 is a multiple of phi(n), even, - # and can be represented as t*2^s. - t = ktot - while t%2==0: - t=divmod(t,2)[0] - # Cycle through all multiplicative inverses in Zn. - # The algorithm is non-deterministic, but there is a 50% chance - # any candidate a leads to successful factoring. - # See "Digitalized Signatures and Public Key Functions as Intractable - # as Factorization", M. Rabin, 1979 - spotted = 0 - a = 2 - while not spotted and a<100: - k = t - # Cycle through all values a^{t*2^i}=a^k - while k<ktot: - cand = pow(a,k,n) - # Check if a^k is a non-trivial root of unity (mod n) - if cand!=1 and cand!=(n-1) and pow(cand,2,n)==1: - # We have found a number such that (cand-1)(cand+1)=0 (mod n). - # Either of the terms divides n. - obj.p = GCD(cand+1,n) - spotted = 1 - break - k = k*2 - # This value was not any good... let's try another! - a = a+2 - if not spotted: - raise ValueError("Unable to compute factors p and q from exponent d.") - # Found ! - assert ((n % obj.p)==0) - obj.q = divmod(n,obj.p)[0] - if u is not None: - obj.u = u - else: - obj.u = inverse(obj.p, obj.q) - return obj - -class _DSAKey(object): - def size(self): - """Return the maximum number of bits that can be encrypted""" - return size(self.p) - 1 - - def has_private(self): - return hasattr(self, 'x') - - def _sign(self, m, k): # 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 (1 < k < self.q): - raise ValueError("k is not between 2 and q-1") - inv_k = inverse(k, self.q) # Compute k**-1 mod q - 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 - return (r, s) - - def _verify(self, m, r, s): - # SECURITY TODO - We _should_ be computing SHA1(m), but we don't because that's the API. - if not (0 < r < self.q) or not (0 < s < self.q): - return False - w = inverse(s, self.q) - u1 = (m*w) % self.q - u2 = (r*w) % self.q - v = (pow(self.g, u1, self.p) * pow(self.y, u2, self.p) % self.p) % self.q - return v == r - -def dsa_construct(y, g, p, q, x=None): - assert isinstance(y, int) - assert isinstance(g, int) - assert isinstance(p, int) - assert isinstance(q, int) - assert isinstance(x, (int, type(None))) - obj = _DSAKey() - obj.y = y - obj.g = g - obj.p = p - obj.q = q - if x is not None: obj.x = x - return obj - - -# vim:set ts=4 sw=4 sts=4 expandtab: - |