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

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