mdw@git.distorted.org.uk Git - catacomb-python/blob - catacomb/__init__.py

   1 ### -*-python-*-
   2 ###
   3 ### Setup for Catacomb/Python bindings
   4 ###
   5 ### (c) 2004 Straylight/Edgeware
   6 ###
   7
   8 ###----- Licensing notice ---------------------------------------------------
   9 ###
  10 ### This file is part of the Python interface to Catacomb.
  11 ###
  12 ### Catacomb/Python is free software; you can redistribute it and/or modify
  13 ### it under the terms of the GNU General Public License as published by
  14 ### the Free Software Foundation; either version 2 of the License, or
  15 ### (at your option) any later version.
  16 ###
  17 ### Catacomb/Python is distributed in the hope that it will be useful,
  18 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ### GNU General Public License for more details.
  21 ###
  22 ### You should have received a copy of the GNU General Public License
  23 ### along with Catacomb/Python; if not, write to the Free Software Foundation,
  24 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 import _base
  27 import types as _types
  28 from binascii import hexlify as _hexify, unhexlify as _unhexify
  29 from sys import argv as _argv
  30
  31 ###--------------------------------------------------------------------------
  32 ### Basic stuff.
  33
  34 ## For the benefit of the default keyreporter, we need the program na,e.
  35 _base._ego(_argv[0])
  36
  37 ## Initialize the module.  Drag in the static methods of the various
  38 ## classes; create names for the various known crypto algorithms.
  39 def _init():
  40   d = globals()
  41   b = _base.__dict__;
  42   for i in b:
  43     if i[0] != '_':
  44       d[i] = b[i];
  45   for i in ['MP', 'GF', 'Field',
  46             'ECPt', 'ECPtCurve', 'ECCurve', 'ECInfo',
  47             'DHInfo', 'BinDHInfo', 'RSAPriv', 'BBSPriv',
  48             'PrimeFilter', 'RabinMiller',
  49             'Group', 'GE',
  50             'KeySZ', 'KeyData']:
  51     c = d[i]
  52     pre = '_' + i + '_'
  53     plen = len(pre)
  54     for j in b:
  55       if j[:plen] == pre:
  56         setattr(c, j[plen:], classmethod(b[j]))
  57   for i in [gcciphers, gchashes, gcmacs, gcprps]:
  58     for c in i.itervalues():
  59       d[c.name.replace('-', '_')] = c
  60   for c in gccrands.itervalues():
  61     d[c.name.replace('-', '_') + 'rand'] = c
  62 _init()
  63
  64 ## A handy function for our work: add the methods of a named class to an
  65 ## existing class.  This is how we write the Python-implemented parts of our
  66 ## mostly-C types.
  67 def _augment(c, cc):
  68   for i in cc.__dict__:
  69     a = cc.__dict__[i]
  70     if type(a) is _types.MethodType:
  71       a = a.im_func
  72     elif type(a) not in (_types.FunctionType, staticmethod, classmethod):
  73       continue
  74     setattr(c, i, a)
  75
  76 ## Parsing functions tend to return the object parsed and the remainder of
  77 ## the input.  This checks that the remainder is input and, if so, returns
  78 ## just the object.
  79 def _checkend(r):
  80   x, rest = r
  81   if rest != '':
  82     raise SyntaxError, 'junk at end of string'
  83   return x
  84
  85 ###--------------------------------------------------------------------------
  86 ### Bytestrings.
  87
  88 class _tmp:
  89   def fromhex(x):
  90     return ByteString(_unhexify(x))
  91   fromhex = staticmethod(fromhex)
  92   def __hex__(me):
  93     return _hexify(me)
  94   def __repr__(me):
  95     return 'bytes(%r)' % hex(me)
  96 _augment(ByteString, _tmp)
  97 bytes = ByteString.fromhex
  98
  99 ###--------------------------------------------------------------------------
 100 ### Multiprecision integers and binary polynomials.
 101
 102 def _split_rat(x):
 103   if isinstance(x, Rat): return x._n, x._d
 104   else: return x, 1
 105 class Rat (object):
 106   def __new__(cls, a, b):
 107     a, b = MP(a), MP(b)
 108     q, r = divmod(a, b)
 109     if r == 0: return q
 110     g = b.gcd(r)
 111     me = super(Rat, cls).__new__(cls)
 112     me._n = a//g
 113     me._d = b//g
 114     return me
 115   @property
 116   def numer(me): return me._n
 117   @property
 118   def denom(me): return me._d
 119   def __str__(me): return '%s/%s' % (me._n, me._d)
 120   def __repr__(me): return 'Rat(%s, %s)' % (me._n, me._d)
 121
 122   def __add__(me, you):
 123     n, d = _split_rat(you)
 124     return Rat(me._n*d + n*me._d, d*me._d)
 125   __radd__ = __add__
 126   def __sub__(me, you):
 127     n, d = _split_rat(you)
 128     return Rat(me._n*d - n*me._d, d*me._d)
 129   def __rsub__(me, you):
 130     n, d = _split_rat(you)
 131     return Rat(n*me._d - me._n*d, d*me._d)
 132   def __mul__(me, you):
 133     n, d = _split_rat(you)
 134     return Rat(me._n*n, me._d*d)
 135   def __div__(me, you):
 136     n, d = _split_rat(you)
 137     return Rat(me._n*d, me._d*n)
 138   def __rdiv__(me, you):
 139     n, d = _split_rat(you)
 140     return Rat(me._d*n, me._n*d)
 141   def __cmp__(me, you):
 142     n, d = _split_rat(you)
 143     return cmp(me._n*d, n*me._d)
 144   def __rcmp__(me, you):
 145     n, d = _split_rat(you)
 146     return cmp(n*me._d, me._n*d)
 147
 148 class _tmp:
 149   def negp(x): return x < 0
 150   def posp(x): return x > 0
 151   def zerop(x): return x == 0
 152   def oddp(x): return x.testbit(0)
 153   def evenp(x): return not x.testbit(0)
 154   def mont(x): return MPMont(x)
 155   def barrett(x): return MPBarrett(x)
 156   def reduce(x): return MPReduce(x)
 157   def __div__(me, you): return Rat(me, you)
 158   def __rdiv__(me, you): return Rat(you, me)
 159 _augment(MP, _tmp)
 160
 161 class _tmp:
 162   def zerop(x): return x == 0
 163   def reduce(x): return GFReduce(x)
 164   def trace(x, y): return x.reduce().trace(y)
 165   def halftrace(x, y): return x.reduce().halftrace(y)
 166   def modsqrt(x, y): return x.reduce().sqrt(y)
 167   def quadsolve(x, y): return x.reduce().quadsolve(y)
 168 _augment(GF, _tmp)
 169
 170 class _tmp:
 171   def product(*arg):
 172     'product(ITERABLE) or product(I, ...) -> PRODUCT'
 173     return MPMul(*arg).done()
 174   product = staticmethod(product)
 175 _augment(MPMul, _tmp)
 176
 177 ###--------------------------------------------------------------------------
 178 ### Abstract fields.
 179
 180 class _tmp:
 181   def fromstring(str): return _checkend(Field.parse(str))
 182   fromstring = staticmethod(fromstring)
 183 _augment(Field, _tmp)
 184
 185 class _tmp:
 186   def __repr__(me): return '%s(%sL)' % (type(me).__name__, me.p)
 187   def ec(me, a, b): return ECPrimeProjCurve(me, a, b)
 188 _augment(PrimeField, _tmp)
 189
 190 class _tmp:
 191   def __repr__(me): return '%s(%sL)' % (type(me).__name__, hex(me.p))
 192   def ec(me, a, b): return ECBinProjCurve(me, a, b)
 193 _augment(BinField, _tmp)
 194
 195 class _tmp:
 196   def __str__(me): return str(me.value)
 197   def __repr__(me): return '%s(%s)' % (repr(me.field), repr(me.value))
 198 _augment(FE, _tmp)
 199
 200 ###--------------------------------------------------------------------------
 201 ### Elliptic curves.
 202
 203 class _tmp:
 204   def __repr__(me):
 205     return '%s(%r, %s, %s)' % (type(me).__name__, me.field, me.a, me.b)
 206   def frombuf(me, s):
 207     return ecpt.frombuf(me, s)
 208   def fromraw(me, s):
 209     return ecpt.fromraw(me, s)
 210   def pt(me, *args):
 211     return me(*args)
 212 _augment(ECCurve, _tmp)
 213
 214 class _tmp:
 215   def __repr__(me):
 216     if not me: return 'ECPt()'
 217     return 'ECPt(%s, %s)' % (me.ix, me.iy)
 218   def __str__(me):
 219     if not me: return 'inf'
 220     return '(%s, %s)' % (me.ix, me.iy)
 221 _augment(ECPt, _tmp)
 222
 223 class _tmp:
 224   def __repr__(me):
 225     return 'ECInfo(curve = %r, G = %r, r = %s, h = %s)' % \
 226            (me.curve, me.G, me.r, me.h)
 227   def group(me):
 228     return ECGroup(me)
 229 _augment(ECInfo, _tmp)
 230
 231 class _tmp:
 232   def __repr__(me):
 233     if not me: return '%r()' % (me.curve)
 234     return '%r(%s, %s)' % (me.curve, me.x, me.y)
 235   def __str__(me):
 236     if not me: return 'inf'
 237     return '(%s, %s)' % (me.x, me.y)
 238 _augment(ECPtCurve, _tmp)
 239
 240 ###--------------------------------------------------------------------------
 241 ### Key sizes.
 242
 243 class _tmp:
 244   def __repr__(me): return 'KeySZAny(%d)' % me.default
 245   def check(me, sz): return True
 246   def best(me, sz): return sz
 247 _augment(KeySZAny, _tmp)
 248
 249 class _tmp:
 250   def __repr__(me):
 251     return 'KeySZRange(%d, %d, %d, %d)' % \
 252            (me.default, me.min, me.max, me.mod)
 253   def check(me, sz): return me.min <= sz <= me.max and sz % me.mod == 0
 254   def best(me, sz):
 255     if sz < me.min: raise ValueError, 'key too small'
 256     elif sz > me.max: return me.max
 257     else: return sz - (sz % me.mod)
 258 _augment(KeySZRange, _tmp)
 259
 260 class _tmp:
 261   def __repr__(me): return 'KeySZSet(%d, %s)' % (me.default, me.set)
 262   def check(me, sz): return sz in me.set
 263   def best(me, sz):
 264     found = -1
 265     for i in me.set:
 266       if found < i <= sz: found = i
 267     if found < 0: raise ValueError, 'key too small'
 268     return found
 269 _augment(KeySZSet, _tmp)
 270
 271 ###--------------------------------------------------------------------------
 272 ### Abstract groups.
 273
 274 class _tmp:
 275   def __repr__(me):
 276     return '%s(p = %s, r = %s, g = %s)' % \
 277            (type(me).__name__, me.p, me.r, me.g)
 278 _augment(FGInfo, _tmp)
 279
 280 class _tmp:
 281   def group(me): return PrimeGroup(me)
 282 _augment(DHInfo, _tmp)
 283
 284 class _tmp:
 285   def group(me): return BinGroup(me)
 286 _augment(BinDHInfo, _tmp)
 287
 288 class _tmp:
 289   def __repr__(me):
 290     return '%s(%r)' % (type(me).__name__, me.info)
 291 _augment(Group, _tmp)
 292
 293 class _tmp:
 294   def __repr__(me):
 295     return '%r(%r)' % (me.group, str(me))
 296 _augment(GE, _tmp)
 297
 298 ###--------------------------------------------------------------------------
 299 ### RSA encoding techniques.
 300
 301 class PKCS1Crypt (object):
 302   def __init__(me, ep = '', rng = rand):
 303     me.ep = ep
 304     me.rng = rng
 305   def encode(me, msg, nbits):
 306     return _base._p1crypt_encode(msg, nbits, me.ep, me.rng)
 307   def decode(me, ct, nbits):
 308     return _base._p1crypt_decode(ct, nbits, me.ep, me.rng)
 309
 310 class PKCS1Sig (object):
 311   def __init__(me, ep = '', rng = rand):
 312     me.ep = ep
 313     me.rng = rng
 314   def encode(me, msg, nbits):
 315     return _base._p1sig_encode(msg, nbits, me.ep, me.rng)
 316   def decode(me, msg, sig, nbits):
 317     return _base._p1sig_decode(msg, sig, nbits, me.ep, me.rng)
 318
 319 class OAEP (object):
 320   def __init__(me, mgf = sha_mgf, hash = sha, ep = '', rng = rand):
 321     me.mgf = mgf
 322     me.hash = hash
 323     me.ep = ep
 324     me.rng = rng
 325   def encode(me, msg, nbits):
 326     return _base._oaep_encode(msg, nbits, me.mgf, me.hash, me.ep, me.rng)
 327   def decode(me, ct, nbits):
 328     return _base._oaep_decode(ct, nbits, me.mgf, me.hash, me.ep, me.rng)
 329
 330 class PSS (object):
 331   def __init__(me, mgf = sha_mgf, hash = sha, saltsz = None, rng = rand):
 332     me.mgf = mgf
 333     me.hash = hash
 334     if saltsz is None:
 335       saltsz = hash.hashsz
 336     me.saltsz = saltsz
 337     me.rng = rng
 338   def encode(me, msg, nbits):
 339     return _base._pss_encode(msg, nbits, me.mgf, me.hash, me.saltsz, me.rng)
 340   def decode(me, msg, sig, nbits):
 341     return _base._pss_decode(msg, sig, nbits,
 342                              me.mgf, me.hash, me.saltsz, me.rng)
 343
 344 class _tmp:
 345   def encrypt(me, msg, enc):
 346     return me.pubop(enc.encode(msg, me.n.nbits))
 347   def verify(me, msg, sig, enc):
 348     if msg is None: return enc.decode(msg, me.pubop(sig), me.n.nbits)
 349     try:
 350       x = enc.decode(msg, me.pubop(sig), me.n.nbits)
 351       return x is None or x == msg
 352     except ValueError:
 353       return False
 354 _augment(RSAPub, _tmp)
 355
 356 class _tmp:
 357   def decrypt(me, ct, enc): return enc.decode(me.privop(ct), me.n.nbits)
 358   def sign(me, msg, enc): return me.privop(enc.encode(msg, me.n.nbits))
 359 _augment(RSAPriv, _tmp)
 360
 361 ###--------------------------------------------------------------------------
 362 ### Built-in named curves and prime groups.
 363
 364 class _groupmap (object):
 365   def __init__(me, map, nth):
 366     me.map = map
 367     me.nth = nth
 368     me.i = [None] * (max(map.values()) + 1)
 369   def __repr__(me):
 370     return '{%s}' % ', '.join(['%r: %r' % (k, me[k]) for k in me])
 371   def __contains__(me, k):
 372     return k in me.map
 373   def __getitem__(me, k):
 374     i = me.map[k]
 375     if me.i[i] is None:
 376       me.i[i] = me.nth(i)
 377     return me.i[i]
 378   def __setitem__(me, k, v):
 379     raise TypeError, "immutable object"
 380   def __iter__(me):
 381     return iter(me.map)
 382   def iterkeys(me):
 383     return iter(me.map)
 384   def itervalues(me):
 385     for k in me:
 386       yield me[k]
 387   def iteritems(me):
 388     for k in me:
 389       yield k, me[k]
 390   def keys(me):
 391     return [k for k in me]
 392   def values(me):
 393     return [me[k] for k in me]
 394   def items(me):
 395     return [(k, me[k]) for k in me]
 396 eccurves = _groupmap(_base._eccurves, ECInfo._curven)
 397 primegroups = _groupmap(_base._pgroups, DHInfo._groupn)
 398 bingroups = _groupmap(_base._bingroups, BinDHInfo._groupn)
 399
 400 ###--------------------------------------------------------------------------
 401 ### Prime number generation.
 402
 403 class PrimeGenEventHandler (object):
 404   def pg_begin(me, ev):
 405     return me.pg_try(ev)
 406   def pg_done(me, ev):
 407     return PGEN_DONE
 408   def pg_abort(me, ev):
 409     return PGEN_TRY
 410   def pg_fail(me, ev):
 411     return PGEN_TRY
 412   def pg_pass(me, ev):
 413     return PGEN_TRY
 414
 415 class SophieGermainStepJump (object):
 416   def pg_begin(me, ev):
 417     me.lf = PrimeFilter(ev.x)
 418     me.hf = me.lf.muladd(2, 1)
 419     return me.cont(ev)
 420   def pg_try(me, ev):
 421     me.step()
 422     return me.cont(ev)
 423   def cont(me, ev):
 424     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 425       me.step()
 426     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 427       return PGEN_ABORT
 428     ev.x = me.lf.x
 429     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 430       return PGEN_DONE
 431     return PGEN_TRY
 432   def pg_done(me, ev):
 433     del me.lf
 434     del me.hf
 435
 436 class SophieGermainStepper (SophieGermainStepJump):
 437   def __init__(me, step):
 438     me.lstep = step;
 439     me.hstep = 2 * step
 440   def step(me):
 441     me.lf.step(me.lstep)
 442     me.hf.step(me.hstep)
 443
 444 class SophieGermainJumper (SophieGermainStepJump):
 445   def __init__(me, jump):
 446     me.ljump = PrimeFilter(jump);
 447     me.hjump = me.ljump.muladd(2, 0)
 448   def step(me):
 449     me.lf.jump(me.ljump)
 450     me.hf.jump(me.hjump)
 451   def pg_done(me, ev):
 452     del me.ljump
 453     del me.hjump
 454     SophieGermainStepJump.pg_done(me, ev)
 455
 456 class SophieGermainTester (object):
 457   def __init__(me):
 458     pass
 459   def pg_begin(me, ev):
 460     me.lr = RabinMiller(ev.x)
 461     me.hr = RabinMiller(2 * ev.x + 1)
 462   def pg_try(me, ev):
 463     lst = me.lr.test(ev.rng.range(me.lr.x))
 464     if lst != PGEN_PASS and lst != PGEN_DONE:
 465       return lst
 466     rst = me.hr.test(ev.rng.range(me.hr.x))
 467     if rst != PGEN_PASS and rst != PGEN_DONE:
 468       return rst
 469     if lst == PGEN_DONE and rst == PGEN_DONE:
 470       return PGEN_DONE
 471     return PGEN_PASS
 472   def pg_done(me, ev):
 473     del me.lr
 474     del me.hr
 475
 476 class PrimitiveStepper (PrimeGenEventHandler):
 477   def __init__(me):
 478     pass
 479   def pg_try(me, ev):
 480     ev.x = me.i.next()
 481     return PGEN_TRY
 482   def pg_begin(me, ev):
 483     me.i = iter(smallprimes)
 484     return me.pg_try(ev)
 485
 486 class PrimitiveTester (PrimeGenEventHandler):
 487   def __init__(me, mod, hh = [], exp = None):
 488     me.mod = MPMont(mod)
 489     me.exp = exp
 490     me.hh = hh
 491   def pg_try(me, ev):
 492     x = ev.x
 493     if me.exp is not None:
 494       x = me.mod.exp(x, me.exp)
 495       if x == 1: return PGEN_FAIL
 496     for h in me.hh:
 497       if me.mod.exp(x, h) == 1: return PGEN_FAIL
 498     ev.x = x
 499     return PGEN_DONE
 500
 501 class SimulStepper (PrimeGenEventHandler):
 502   def __init__(me, mul = 2, add = 1, step = 2):
 503     me.step = step
 504     me.mul = mul
 505     me.add = add
 506   def _stepfn(me, step):
 507     if step <= 0:
 508       raise ValueError, 'step must be positive'
 509     if step <= MPW_MAX:
 510       return lambda f: f.step(step)
 511     j = PrimeFilter(step)
 512     return lambda f: f.jump(j)
 513   def pg_begin(me, ev):
 514     x = ev.x
 515     me.lf = PrimeFilter(x)
 516     me.hf = PrimeFilter(x * me.mul + me.add)
 517     me.lstep = me._stepfn(me.step)
 518     me.hstep = me._stepfn(me.step * me.mul)
 519     SimulStepper._cont(me, ev)
 520   def pg_try(me, ev):
 521     me._step()
 522     me._cont(ev)
 523   def _step(me):
 524     me.lstep(me.lf)
 525     me.hstep(me.hf)
 526   def _cont(me, ev):
 527     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 528       me._step()
 529     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 530       return PGEN_ABORT
 531     ev.x = me.lf.x
 532     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 533       return PGEN_DONE
 534     return PGEN_TRY
 535   def pg_done(me, ev):
 536     del me.lf
 537     del me.hf
 538     del me.lstep
 539     del me.hstep
 540
 541 class SimulTester (PrimeGenEventHandler):
 542   def __init__(me, mul = 2, add = 1):
 543     me.mul = mul
 544     me.add = add
 545   def pg_begin(me, ev):
 546     x = ev.x
 547     me.lr = RabinMiller(x)
 548     me.hr = RabinMiller(x * me.mul + me.add)
 549   def pg_try(me, ev):
 550     lst = me.lr.test(ev.rng.range(me.lr.x))
 551     if lst != PGEN_PASS and lst != PGEN_DONE:
 552       return lst
 553     rst = me.hr.test(ev.rng.range(me.hr.x))
 554     if rst != PGEN_PASS and rst != PGEN_DONE:
 555       return rst
 556     if lst == PGEN_DONE and rst == PGEN_DONE:
 557       return PGEN_DONE
 558     return PGEN_PASS
 559   def pg_done(me, ev):
 560     del me.lr
 561     del me.hr
 562
 563 def sgprime(start, step = 2, name = 'p', event = pgen_nullev, nsteps = 0):
 564   start = MP(start)
 565   return pgen(start, name, SimulStepper(step = step), SimulTester(), event,
 566               nsteps, RabinMiller.iters(start.nbits))
 567
 568 def findprimitive(mod, hh = [], exp = None, name = 'g', event = pgen_nullev):
 569   return pgen(0, name, PrimitiveStepper(), PrimitiveTester(mod, hh, exp),
 570               event, 0, 1)
 571
 572 def kcdsaprime(pbits, qbits, rng = rand,
 573                event = pgen_nullev, name = 'p', nsteps = 0):
 574   hbits = pbits - qbits
 575   h = pgen(rng.mp(hbits, 1), name + ' [h]',
 576            PrimeGenStepper(2), PrimeGenTester(),
 577            event, nsteps, RabinMiller.iters(hbits))
 578   q = pgen(rng.mp(qbits, 1), name, SimulStepper(2 * h, 1, 2),
 579            SimulTester(2 * h, 1), event, nsteps, RabinMiller.iters(qbits))
 580   p = 2 * q * h + 1
 581   return p, q, h
 582
 583 #----- That's all, folks ----------------------------------------------------