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 class _tmp:
 103   def negp(x): return x < 0
 104   def posp(x): return x > 0
 105   def zerop(x): return x == 0
 106   def oddp(x): return x.testbit(0)
 107   def evenp(x): return not x.testbit(0)
 108   def mont(x): return MPMont(x)
 109   def barrett(x): return MPBarrett(x)
 110   def reduce(x): return MPReduce(x)
 111 _augment(MP, _tmp)
 112
 113 class _tmp:
 114   def zerop(x): return x == 0
 115   def reduce(x): return GFReduce(x)
 116   def trace(x, y): return x.reduce().trace(y)
 117   def halftrace(x, y): return x.reduce().halftrace(y)
 118   def modsqrt(x, y): return x.reduce().sqrt(y)
 119   def quadsolve(x, y): return x.reduce().quadsolve(y)
 120 _augment(GF, _tmp)
 121
 122 class _tmp:
 123   def product(*arg):
 124     'product(ITERABLE) or product(I, ...) -> PRODUCT'
 125     return MPMul(*arg).done()
 126   product = staticmethod(product)
 127 _augment(MPMul, _tmp)
 128
 129 ###--------------------------------------------------------------------------
 130 ### Abstract fields.
 131
 132 class _tmp:
 133   def fromstring(str): return _checkend(Field.parse(str))
 134   fromstring = staticmethod(fromstring)
 135 _augment(Field, _tmp)
 136
 137 class _tmp:
 138   def __repr__(me): return '%s(%sL)' % (type(me).__name__, me.p)
 139   def ec(me, a, b): return ECPrimeProjCurve(me, a, b)
 140 _augment(PrimeField, _tmp)
 141
 142 class _tmp:
 143   def __repr__(me): return '%s(%sL)' % (type(me).__name__, hex(me.p))
 144   def ec(me, a, b): return ECBinProjCurve(me, a, b)
 145 _augment(BinField, _tmp)
 146
 147 class _tmp:
 148   def __str__(me): return str(me.value)
 149   def __repr__(me): return '%s(%s)' % (repr(me.field), repr(me.value))
 150 _augment(FE, _tmp)
 151
 152 ###--------------------------------------------------------------------------
 153 ### Elliptic curves.
 154
 155 class _tmp:
 156   def __repr__(me):
 157     return '%s(%r, %s, %s)' % (type(me).__name__, me.field, me.a, me.b)
 158   def frombuf(me, s):
 159     return ecpt.frombuf(me, s)
 160   def fromraw(me, s):
 161     return ecpt.fromraw(me, s)
 162   def pt(me, *args):
 163     return me(*args)
 164 _augment(ECCurve, _tmp)
 165
 166 class _tmp:
 167   def __repr__(me):
 168     if not me: return 'ECPt()'
 169     return 'ECPt(%s, %s)' % (me.ix, me.iy)
 170   def __str__(me):
 171     if not me: return 'inf'
 172     return '(%s, %s)' % (me.ix, me.iy)
 173 _augment(ECPt, _tmp)
 174
 175 class _tmp:
 176   def __repr__(me):
 177     return 'ECInfo(curve = %r, G = %r, r = %s, h = %s)' % \
 178            (me.curve, me.G, me.r, me.h)
 179   def group(me):
 180     return ECGroup(me)
 181 _augment(ECInfo, _tmp)
 182
 183 class _tmp:
 184   def __repr__(me):
 185     if not me: return '%r()' % (me.curve)
 186     return '%r(%s, %s)' % (me.curve, me.x, me.y)
 187   def __str__(me):
 188     if not me: return 'inf'
 189     return '(%s, %s)' % (me.x, me.y)
 190 _augment(ECPtCurve, _tmp)
 191
 192 ###--------------------------------------------------------------------------
 193 ### Key sizes.
 194
 195 class _tmp:
 196   def __repr__(me): return 'KeySZAny(%d)' % me.default
 197   def check(me, sz): return True
 198   def best(me, sz): return sz
 199 _augment(KeySZAny, _tmp)
 200
 201 class _tmp:
 202   def __repr__(me):
 203     return 'KeySZRange(%d, %d, %d, %d)' % \
 204            (me.default, me.min, me.max, me.mod)
 205   def check(me, sz): return me.min <= sz <= me.max and sz % me.mod == 0
 206   def best(me, sz):
 207     if sz < me.min: raise ValueError, 'key too small'
 208     elif sz > me.max: return me.max
 209     else: return sz - (sz % me.mod)
 210 _augment(KeySZRange, _tmp)
 211
 212 class _tmp:
 213   def __repr__(me): return 'KeySZSet(%d, %s)' % (me.default, me.set)
 214   def check(me, sz): return sz in me.set
 215   def best(me, sz):
 216     found = -1
 217     for i in me.set:
 218       if found < i <= sz: found = i
 219     if found < 0: raise ValueError, 'key too small'
 220     return found
 221 _augment(KeySZSet, _tmp)
 222
 223 ###--------------------------------------------------------------------------
 224 ### Abstract groups.
 225
 226 class _tmp:
 227   def __repr__(me):
 228     return '%s(p = %s, r = %s, g = %s)' % \
 229            (type(me).__name__, me.p, me.r, me.g)
 230 _augment(FGInfo, _tmp)
 231
 232 class _tmp:
 233   def group(me): return PrimeGroup(me)
 234 _augment(DHInfo, _tmp)
 235
 236 class _tmp:
 237   def group(me): return BinGroup(me)
 238 _augment(BinDHInfo, _tmp)
 239
 240 class _tmp:
 241   def __repr__(me):
 242     return '%s(%r)' % (type(me).__name__, me.info)
 243 _augment(Group, _tmp)
 244
 245 class _tmp:
 246   def __repr__(me):
 247     return '%r(%r)' % (me.group, str(me))
 248 _augment(GE, _tmp)
 249
 250 ###--------------------------------------------------------------------------
 251 ### RSA encoding techniques.
 252
 253 class PKCS1Crypt (object):
 254   def __init__(me, ep = '', rng = rand):
 255     me.ep = ep
 256     me.rng = rng
 257   def encode(me, msg, nbits):
 258     return _base._p1crypt_encode(msg, nbits, me.ep, me.rng)
 259   def decode(me, ct, nbits):
 260     return _base._p1crypt_decode(ct, nbits, me.ep, me.rng)
 261
 262 class PKCS1Sig (object):
 263   def __init__(me, ep = '', rng = rand):
 264     me.ep = ep
 265     me.rng = rng
 266   def encode(me, msg, nbits):
 267     return _base._p1sig_encode(msg, nbits, me.ep, me.rng)
 268   def decode(me, msg, sig, nbits):
 269     return _base._p1sig_decode(msg, sig, nbits, me.ep, me.rng)
 270
 271 class OAEP (object):
 272   def __init__(me, mgf = sha_mgf, hash = sha, ep = '', rng = rand):
 273     me.mgf = mgf
 274     me.hash = hash
 275     me.ep = ep
 276     me.rng = rng
 277   def encode(me, msg, nbits):
 278     return _base._oaep_encode(msg, nbits, me.mgf, me.hash, me.ep, me.rng)
 279   def decode(me, ct, nbits):
 280     return _base._oaep_decode(ct, nbits, me.mgf, me.hash, me.ep, me.rng)
 281
 282 class PSS (object):
 283   def __init__(me, mgf = sha_mgf, hash = sha, saltsz = None, rng = rand):
 284     me.mgf = mgf
 285     me.hash = hash
 286     if saltsz is None:
 287       saltsz = hash.hashsz
 288     me.saltsz = saltsz
 289     me.rng = rng
 290   def encode(me, msg, nbits):
 291     return _base._pss_encode(msg, nbits, me.mgf, me.hash, me.saltsz, me.rng)
 292   def decode(me, msg, sig, nbits):
 293     return _base._pss_decode(msg, sig, nbits,
 294                              me.mgf, me.hash, me.saltsz, me.rng)
 295
 296 class _tmp:
 297   def encrypt(me, msg, enc):
 298     return me.pubop(enc.encode(msg, me.n.nbits))
 299   def verify(me, msg, sig, enc):
 300     if msg is None: return enc.decode(msg, me.pubop(sig), me.n.nbits)
 301     try:
 302       x = enc.decode(msg, me.pubop(sig), me.n.nbits)
 303       return x is None or x == msg
 304     except ValueError:
 305       return False
 306 _augment(RSAPub, _tmp)
 307
 308 class _tmp:
 309   def decrypt(me, ct, enc): return enc.decode(me.privop(ct), me.n.nbits)
 310   def sign(me, msg, enc): return me.privop(enc.encode(msg, me.n.nbits))
 311 _augment(RSAPriv, _tmp)
 312
 313 ###--------------------------------------------------------------------------
 314 ### Built-in named curves and prime groups.
 315
 316 class _groupmap (object):
 317   def __init__(me, map, nth):
 318     me.map = map
 319     me.nth = nth
 320     me.i = [None] * (max(map.values()) + 1)
 321   def __repr__(me):
 322     return '{%s}' % ', '.join(['%r: %r' % (k, me[k]) for k in me])
 323   def __contains__(me, k):
 324     return k in me.map
 325   def __getitem__(me, k):
 326     i = me.map[k]
 327     if me.i[i] is None:
 328       me.i[i] = me.nth(i)
 329     return me.i[i]
 330   def __setitem__(me, k, v):
 331     raise TypeError, "immutable object"
 332   def __iter__(me):
 333     return iter(me.map)
 334   def iterkeys(me):
 335     return iter(me.map)
 336   def itervalues(me):
 337     for k in me:
 338       yield me[k]
 339   def iteritems(me):
 340     for k in me:
 341       yield k, me[k]
 342   def keys(me):
 343     return [k for k in me]
 344   def values(me):
 345     return [me[k] for k in me]
 346   def items(me):
 347     return [(k, me[k]) for k in me]
 348 eccurves = _groupmap(_base._eccurves, ECInfo._curven)
 349 primegroups = _groupmap(_base._pgroups, DHInfo._groupn)
 350 bingroups = _groupmap(_base._bingroups, BinDHInfo._groupn)
 351
 352 ###--------------------------------------------------------------------------
 353 ### Prime number generation.
 354
 355 class PrimeGenEventHandler (object):
 356   def pg_begin(me, ev):
 357     return me.pg_try(ev)
 358   def pg_done(me, ev):
 359     return PGEN_DONE
 360   def pg_abort(me, ev):
 361     return PGEN_TRY
 362   def pg_fail(me, ev):
 363     return PGEN_TRY
 364   def pg_pass(me, ev):
 365     return PGEN_TRY
 366
 367 class SophieGermainStepJump (object):
 368   def pg_begin(me, ev):
 369     me.lf = PrimeFilter(ev.x)
 370     me.hf = me.lf.muladd(2, 1)
 371     return me.cont(ev)
 372   def pg_try(me, ev):
 373     me.step()
 374     return me.cont(ev)
 375   def cont(me, ev):
 376     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 377       me.step()
 378     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 379       return PGEN_ABORT
 380     ev.x = me.lf.x
 381     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 382       return PGEN_DONE
 383     return PGEN_TRY
 384   def pg_done(me, ev):
 385     del me.lf
 386     del me.hf
 387
 388 class SophieGermainStepper (SophieGermainStepJump):
 389   def __init__(me, step):
 390     me.lstep = step;
 391     me.hstep = 2 * step
 392   def step(me):
 393     me.lf.step(me.lstep)
 394     me.hf.step(me.hstep)
 395
 396 class SophieGermainJumper (SophieGermainStepJump):
 397   def __init__(me, jump):
 398     me.ljump = PrimeFilter(jump);
 399     me.hjump = me.ljump.muladd(2, 0)
 400   def step(me):
 401     me.lf.jump(me.ljump)
 402     me.hf.jump(me.hjump)
 403   def pg_done(me, ev):
 404     del me.ljump
 405     del me.hjump
 406     SophieGermainStepJump.pg_done(me, ev)
 407
 408 class SophieGermainTester (object):
 409   def __init__(me):
 410     pass
 411   def pg_begin(me, ev):
 412     me.lr = RabinMiller(ev.x)
 413     me.hr = RabinMiller(2 * ev.x + 1)
 414   def pg_try(me, ev):
 415     lst = me.lr.test(ev.rng.range(me.lr.x))
 416     if lst != PGEN_PASS and lst != PGEN_DONE:
 417       return lst
 418     rst = me.hr.test(ev.rng.range(me.hr.x))
 419     if rst != PGEN_PASS and rst != PGEN_DONE:
 420       return rst
 421     if lst == PGEN_DONE and rst == PGEN_DONE:
 422       return PGEN_DONE
 423     return PGEN_PASS
 424   def pg_done(me, ev):
 425     del me.lr
 426     del me.hr
 427
 428 class PrimitiveStepper (PrimeGenEventHandler):
 429   def __init__(me):
 430     pass
 431   def pg_try(me, ev):
 432     ev.x = me.i.next()
 433     return PGEN_TRY
 434   def pg_begin(me, ev):
 435     me.i = iter(smallprimes)
 436     return me.pg_try(ev)
 437
 438 class PrimitiveTester (PrimeGenEventHandler):
 439   def __init__(me, mod, hh = [], exp = None):
 440     me.mod = MPMont(mod)
 441     me.exp = exp
 442     me.hh = hh
 443   def pg_try(me, ev):
 444     x = ev.x
 445     if me.exp is not None:
 446       x = me.mod.exp(x, me.exp)
 447       if x == 1: return PGEN_FAIL
 448     for h in me.hh:
 449       if me.mod.exp(x, h) == 1: return PGEN_FAIL
 450     ev.x = x
 451     return PGEN_DONE
 452
 453 class SimulStepper (PrimeGenEventHandler):
 454   def __init__(me, mul = 2, add = 1, step = 2):
 455     me.step = step
 456     me.mul = mul
 457     me.add = add
 458   def _stepfn(me, step):
 459     if step <= 0:
 460       raise ValueError, 'step must be positive'
 461     if step <= MPW_MAX:
 462       return lambda f: f.step(step)
 463     j = PrimeFilter(step)
 464     return lambda f: f.jump(j)
 465   def pg_begin(me, ev):
 466     x = ev.x
 467     me.lf = PrimeFilter(x)
 468     me.hf = PrimeFilter(x * me.mul + me.add)
 469     me.lstep = me._stepfn(me.step)
 470     me.hstep = me._stepfn(me.step * me.mul)
 471     SimulStepper._cont(me, ev)
 472   def pg_try(me, ev):
 473     me._step()
 474     me._cont(ev)
 475   def _step(me):
 476     me.lstep(me.lf)
 477     me.hstep(me.hf)
 478   def _cont(me, ev):
 479     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 480       me._step()
 481     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 482       return PGEN_ABORT
 483     ev.x = me.lf.x
 484     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 485       return PGEN_DONE
 486     return PGEN_TRY
 487   def pg_done(me, ev):
 488     del me.lf
 489     del me.hf
 490     del me.lstep
 491     del me.hstep
 492
 493 class SimulTester (PrimeGenEventHandler):
 494   def __init__(me, mul = 2, add = 1):
 495     me.mul = mul
 496     me.add = add
 497   def pg_begin(me, ev):
 498     x = ev.x
 499     me.lr = RabinMiller(x)
 500     me.hr = RabinMiller(x * me.mul + me.add)
 501   def pg_try(me, ev):
 502     lst = me.lr.test(ev.rng.range(me.lr.x))
 503     if lst != PGEN_PASS and lst != PGEN_DONE:
 504       return lst
 505     rst = me.hr.test(ev.rng.range(me.hr.x))
 506     if rst != PGEN_PASS and rst != PGEN_DONE:
 507       return rst
 508     if lst == PGEN_DONE and rst == PGEN_DONE:
 509       return PGEN_DONE
 510     return PGEN_PASS
 511   def pg_done(me, ev):
 512     del me.lr
 513     del me.hr
 514
 515 def sgprime(start, step = 2, name = 'p', event = pgen_nullev, nsteps = 0):
 516   start = MP(start)
 517   return pgen(start, name, SimulStepper(step = step), SimulTester(), event,
 518               nsteps, RabinMiller.iters(start.nbits))
 519
 520 def findprimitive(mod, hh = [], exp = None, name = 'g', event = pgen_nullev):
 521   return pgen(0, name, PrimitiveStepper(), PrimitiveTester(mod, hh, exp),
 522               event, 0, 1)
 523
 524 def kcdsaprime(pbits, qbits, rng = rand,
 525                event = pgen_nullev, name = 'p', nsteps = 0):
 526   hbits = pbits - qbits
 527   h = pgen(rng.mp(hbits, 1), name + ' [h]',
 528            PrimeGenStepper(2), PrimeGenTester(),
 529            event, nsteps, RabinMiller.iters(hbits))
 530   q = pgen(rng.mp(qbits, 1), name, SimulStepper(2 * h, 1, 2),
 531            SimulTester(2 * h, 1), event, nsteps, RabinMiller.iters(qbits))
 532   p = 2 * q * h + 1
 533   return p, q, h
 534
 535 #----- That's all, folks ----------------------------------------------------