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 from __future__ import with_statement
  27
  28 from binascii import hexlify as _hexify, unhexlify as _unhexify
  29 from contextlib import contextmanager as _ctxmgr
  30 try: import DLFCN as _dlfcn
  31 except ImportError: _dlfcn = None
  32 import os as _os
  33 from struct import pack as _pack
  34 import sys as _sys
  35 import types as _types
  36
  37 ###--------------------------------------------------------------------------
  38 ### Import the main C extension module.
  39
  40 try:
  41   _dlflags = _odlflags = _sys.getdlopenflags()
  42 except AttributeError:
  43   _dlflags = _odlflags = -1
  44
  45 ## Set the `deep binding' flag.  Python has its own different MD5
  46 ## implementation, and some distributions export `md5_init' and friends so
  47 ## they override our versions, which doesn't end well.  Figure out how to
  48 ## turn this flag on so we don't have the problem.
  49 if _dlflags >= 0:
  50   try: _dlflags |= _dlfcn.RTLD_DEEPBIND
  51   except AttributeError:
  52     try: _dlflags |= _os.RTLD_DEEPBIND
  53     except AttributeError:
  54       if _os.uname()[0] == 'Linux': _dlflags |= 8 # magic knowledge
  55       else: pass # can't do this.
  56   _sys.setdlopenflags(_dlflags)
  57
  58 import _base
  59
  60 if _odlflags >= 0:
  61   _sys.setdlopenflags(_odlflags)
  62
  63 del _dlflags, _odlflags
  64
  65 ###--------------------------------------------------------------------------
  66 ### Basic stuff.
  67
  68 ## For the benefit of the default keyreporter, we need the program name.
  69 _base._ego(_sys.argv[0])
  70
  71 ## Register our module.
  72 _base._set_home_module(_sys.modules[__name__])
  73 def default_lostexchook(why, ty, val, tb):
  74   """`catacomb.lostexchook(WHY, TY, VAL, TB)' reports lost exceptions."""
  75   _sys.stderr.write("\n\n!!! LOST EXCEPTION: %s\n" % why)
  76   _sys.excepthook(ty, val, tb)
  77   _sys.stderr.write("\n")
  78 lostexchook = default_lostexchook
  79
  80 ## How to fix a name back into the right identifier.  Alas, the rules are not
  81 ## consistent.
  82 def _fixname(name):
  83
  84   ## Hyphens consistently become underscores.
  85   name = name.replace('-', '_')
  86
  87   ## But slashes might become underscores or just vanish.
  88   if name.startswith('salsa20'): name = name.replace('/', '')
  89   else: name = name.replace('/', '_')
  90
  91   ## Done.
  92   return name
  93
  94 ## Initialize the module.  Drag in the static methods of the various
  95 ## classes; create names for the various known crypto algorithms.
  96 def _init():
  97   d = globals()
  98   b = _base.__dict__;
  99   for i in b:
 100     if i[0] != '_':
 101       d[i] = b[i];
 102   for i in ['ByteString',
 103             'MP', 'GF', 'Field',
 104             'ECPt', 'ECPtCurve', 'ECCurve', 'ECInfo',
 105             'DHInfo', 'BinDHInfo', 'RSAPriv', 'BBSPriv',
 106             'PrimeFilter', 'RabinMiller',
 107             'Group', 'GE',
 108             'KeySZ', 'KeyData']:
 109     c = d[i]
 110     pre = '_' + i + '_'
 111     plen = len(pre)
 112     for j in b:
 113       if j[:plen] == pre:
 114         setattr(c, j[plen:], classmethod(b[j]))
 115   for i in [gcciphers, gcaeads, gchashes, gcmacs, gcprps]:
 116     for c in i.itervalues():
 117       d[_fixname(c.name)] = c
 118   for c in gccrands.itervalues():
 119     d[_fixname(c.name + 'rand')] = c
 120 _init()
 121
 122 ## A handy function for our work: add the methods of a named class to an
 123 ## existing class.  This is how we write the Python-implemented parts of our
 124 ## mostly-C types.
 125 def _augment(c, cc):
 126   for i in cc.__dict__:
 127     a = cc.__dict__[i]
 128     if type(a) is _types.MethodType:
 129       a = a.im_func
 130     elif type(a) not in (_types.FunctionType, staticmethod, classmethod):
 131       continue
 132     setattr(c, i, a)
 133
 134 ## Parsing functions tend to return the object parsed and the remainder of
 135 ## the input.  This checks that the remainder is input and, if so, returns
 136 ## just the object.
 137 def _checkend(r):
 138   x, rest = r
 139   if rest != '':
 140     raise SyntaxError, 'junk at end of string'
 141   return x
 142
 143 ## Some pretty-printing utilities.
 144 PRINT_SECRETS = False
 145 def _clsname(me): return type(me).__name__
 146 def _repr_secret(thing, secretp = True):
 147   if not secretp or PRINT_SECRETS: return repr(thing)
 148   else: return '#<SECRET>'
 149 def _pp_str(me, pp, cyclep): pp.text(cyclep and '...' or str(me))
 150 def _pp_secret(pp, thing, secretp = True):
 151   if not secretp or PRINT_SECRETS: pp.pretty(thing)
 152   else: pp.text('#<SECRET>')
 153 def _pp_bgroup(pp, text):
 154   ind = len(text)
 155   pp.begin_group(ind, text)
 156   return ind
 157 def _pp_bgroup_tyname(pp, obj, open = '('):
 158   return _pp_bgroup(pp, _clsname(obj) + open)
 159 def _pp_kv(pp, k, v, secretp = False):
 160   ind = _pp_bgroup(pp, k + ' = ')
 161   _pp_secret(pp, v, secretp)
 162   pp.end_group(ind, '')
 163 def _pp_commas(pp, printfn, items):
 164   firstp = True
 165   for i in items:
 166     if firstp: firstp = False
 167     else: pp.text(','); pp.breakable()
 168     printfn(i)
 169 def _pp_dict(pp, items):
 170   def p((k, v)):
 171     pp.begin_group(0)
 172     pp.pretty(k)
 173     pp.text(':')
 174     pp.begin_group(2)
 175     pp.breakable()
 176     pp.pretty(v)
 177     pp.end_group(2)
 178     pp.end_group(0)
 179   _pp_commas(pp, p, items)
 180
 181 ###--------------------------------------------------------------------------
 182 ### Bytestrings.
 183
 184 class _tmp:
 185   def fromhex(x):
 186     return ByteString(_unhexify(x))
 187   fromhex = staticmethod(fromhex)
 188   def __hex__(me):
 189     return _hexify(me)
 190   def __repr__(me):
 191     return 'bytes(%r)' % hex(me)
 192 _augment(ByteString, _tmp)
 193 ByteString.__hash__ = str.__hash__
 194 bytes = ByteString.fromhex
 195
 196 ###--------------------------------------------------------------------------
 197 ### Symmetric encryption.
 198
 199 class _tmp:
 200   def encrypt(me, n, m, tsz = None, h = ByteString('')):
 201     if tsz is None: tsz = me.__class__.tagsz.default
 202     e = me.enc(n, len(h), len(m), tsz)
 203     if not len(h): a = None
 204     else: a = e.aad().hash(h)
 205     c0 = e.encrypt(m)
 206     c1, t = e.done(aad = a)
 207     return c0 + c1, t
 208   def decrypt(me, n, c, t, h = ByteString('')):
 209     d = me.dec(n, len(h), len(c), len(t))
 210     if not len(h): a = None
 211     else: a = d.aad().hash(h)
 212     m = d.decrypt(c)
 213     m += d.done(t, aad = a)
 214     return m
 215 _augment(GAEKey, _tmp)
 216
 217 ###--------------------------------------------------------------------------
 218 ### Hashing.
 219
 220 class _tmp:
 221   def check(me, h):
 222     hh = me.done()
 223     return ctstreq(h, hh)
 224 _augment(GHash, _tmp)
 225 _augment(Poly1305Hash, _tmp)
 226
 227 class _HashBase (object):
 228   ## The standard hash methods.  Assume that `hash' is defined and returns
 229   ## the receiver.
 230   def _check_range(me, n, max):
 231     if not (0 <= n <= max): raise OverflowError("out of range")
 232   def hashu8(me, n):
 233     me._check_range(n, 0xff)
 234     return me.hash(_pack('B', n))
 235   def hashu16l(me, n):
 236     me._check_range(n, 0xffff)
 237     return me.hash(_pack('<H', n))
 238   def hashu16b(me, n):
 239     me._check_range(n, 0xffff)
 240     return me.hash(_pack('>H', n))
 241   hashu16 = hashu16b
 242   def hashu32l(me, n):
 243     me._check_range(n, 0xffffffff)
 244     return me.hash(_pack('<L', n))
 245   def hashu32b(me, n):
 246     me._check_range(n, 0xffffffff)
 247     return me.hash(_pack('>L', n))
 248   hashu32 = hashu32b
 249   def hashu64l(me, n):
 250     me._check_range(n, 0xffffffffffffffff)
 251     return me.hash(_pack('<Q', n))
 252   def hashu64b(me, n):
 253     me._check_range(n, 0xffffffffffffffff)
 254     return me.hash(_pack('>Q', n))
 255   hashu64 = hashu64b
 256   def hashbuf8(me, s): return me.hashu8(len(s)).hash(s)
 257   def hashbuf16l(me, s): return me.hashu16l(len(s)).hash(s)
 258   def hashbuf16b(me, s): return me.hashu16b(len(s)).hash(s)
 259   hashbuf16 = hashbuf16b
 260   def hashbuf32l(me, s): return me.hashu32l(len(s)).hash(s)
 261   def hashbuf32b(me, s): return me.hashu32b(len(s)).hash(s)
 262   hashbuf32 = hashbuf32b
 263   def hashbuf64l(me, s): return me.hashu64l(len(s)).hash(s)
 264   def hashbuf64b(me, s): return me.hashu64b(len(s)).hash(s)
 265   hashbuf64 = hashbuf64b
 266   def hashstrz(me, s): return me.hash(s).hashu8(0)
 267
 268 class _ShakeBase (_HashBase):
 269
 270   ## Python gets really confused if I try to augment `__new__' on native
 271   ## classes, so wrap and delegate.  Sorry.
 272   def __init__(me, perso = '', *args, **kw):
 273     super(_ShakeBase, me).__init__(*args, **kw)
 274     me._h = me._SHAKE(perso = perso, func = me._FUNC)
 275
 276   ## Delegate methods...
 277   def copy(me): new = me.__class__._bare_new(); new._copy(me); return new
 278   def _copy(me, other): me._h = other._h.copy()
 279   def hash(me, m): me._h.hash(m); return me
 280   def xof(me): me._h.xof(); return me
 281   def get(me, n): return me._h.get(n)
 282   def mask(me, m): return me._h.mask(m)
 283   def done(me, n): return me._h.done(n)
 284   def check(me, h): return ctstreq(h, me.done(len(h)))
 285   @property
 286   def state(me): return me._h.state
 287   @property
 288   def buffered(me): return me._h.buffered
 289   @property
 290   def rate(me): return me._h.rate
 291   @classmethod
 292   def _bare_new(cls): return cls()
 293
 294 class _tmp:
 295   def check(me, h):
 296     return ctstreq(h, me.done(len(h)))
 297   def leftenc(me, n):
 298     nn = MP(n).storeb()
 299     return me.hashu8(len(nn)).hash(nn)
 300   def rightenc(me, n):
 301     nn = MP(n).storeb()
 302     return me.hash(nn).hashu8(len(nn))
 303   def stringenc(me, str):
 304     return me.leftenc(8*len(str)).hash(str)
 305   def bytepad_before(me):
 306     return me.leftenc(me.rate)
 307   def bytepad_after(me):
 308     if me.buffered: me.hash(me._Z[:me.rate - me.buffered])
 309     return me
 310   @_ctxmgr
 311   def bytepad(me):
 312     me.bytepad_before()
 313     yield me
 314     me.bytepad_after()
 315 _augment(Shake, _tmp)
 316 _augment(_ShakeBase, _tmp)
 317 Shake._Z = _ShakeBase._Z = ByteString.zero(200)
 318
 319 class KMAC (_ShakeBase):
 320   _FUNC = 'KMAC'
 321   def __init__(me, k, *arg, **kw):
 322     super(KMAC, me).__init__(*arg, **kw)
 323     with me.bytepad(): me.stringenc(k)
 324   def done(me, n = -1):
 325     if n < 0: n = me._TAGSZ
 326     me.rightenc(8*n)
 327     return super(KMAC, me).done(n)
 328   def xof(me):
 329     me.rightenc(0)
 330     return super(KMAC, me).xof()
 331   @classmethod
 332   def _bare_new(cls): return cls("")
 333
 334 class KMAC128 (KMAC): _SHAKE = Shake128; _TAGSZ = 16
 335 class KMAC256 (KMAC): _SHAKE = Shake256; _TAGSZ = 32
 336
 337 ###--------------------------------------------------------------------------
 338 ### NaCl `secretbox'.
 339
 340 def secret_box(k, n, m):
 341   y, t = salsa20_naclbox(k).encrypt(n, m)
 342   return t + y
 343
 344 def secret_unbox(k, n, c):
 345   tsz = poly1305.tagsz
 346   return salsa20_naclbox(k).decrypt(n, c[tsz:], c[0:tsz])
 347
 348 ###--------------------------------------------------------------------------
 349 ### Multiprecision integers and binary polynomials.
 350
 351 def _split_rat(x):
 352   if isinstance(x, BaseRat): return x._n, x._d
 353   else: return x, 1
 354 class BaseRat (object):
 355   """Base class implementing fields of fractions over Euclidean domains."""
 356   def __new__(cls, a, b):
 357     a, b = cls.RING(a), cls.RING(b)
 358     q, r = divmod(a, b)
 359     if r == 0: return q
 360     g = b.gcd(r)
 361     me = super(BaseRat, cls).__new__(cls)
 362     me._n = a//g
 363     me._d = b//g
 364     return me
 365   @property
 366   def numer(me): return me._n
 367   @property
 368   def denom(me): return me._d
 369   def __str__(me): return '%s/%s' % (me._n, me._d)
 370   def __repr__(me): return '%s(%s, %s)' % (_clsname(me), me._n, me._d)
 371   _repr_pretty_ = _pp_str
 372
 373   def __add__(me, you):
 374     n, d = _split_rat(you)
 375     return type(me)(me._n*d + n*me._d, d*me._d)
 376   __radd__ = __add__
 377   def __sub__(me, you):
 378     n, d = _split_rat(you)
 379     return type(me)(me._n*d - n*me._d, d*me._d)
 380   def __rsub__(me, you):
 381     n, d = _split_rat(you)
 382     return type(me)(n*me._d - me._n*d, d*me._d)
 383   def __mul__(me, you):
 384     n, d = _split_rat(you)
 385     return type(me)(me._n*n, me._d*d)
 386   __rmul__ = __mul__
 387   def __truediv__(me, you):
 388     n, d = _split_rat(you)
 389     return type(me)(me._n*d, me._d*n)
 390   def __rtruediv__(me, you):
 391     n, d = _split_rat(you)
 392     return type(me)(me._d*n, me._n*d)
 393   __div__ = __truediv__
 394   __rdiv__ = __rtruediv__
 395   def __cmp__(me, you):
 396     n, d = _split_rat(you)
 397     return cmp(me._n*d, n*me._d)
 398   def __rcmp__(me, you):
 399     n, d = _split_rat(you)
 400     return cmp(n*me._d, me._n*d)
 401
 402 class IntRat (BaseRat):
 403   RING = MP
 404
 405 class GFRat (BaseRat):
 406   RING = GF
 407
 408 class _tmp:
 409   def negp(x): return x < 0
 410   def posp(x): return x > 0
 411   def zerop(x): return x == 0
 412   def oddp(x): return x.testbit(0)
 413   def evenp(x): return not x.testbit(0)
 414   def mont(x): return MPMont(x)
 415   def barrett(x): return MPBarrett(x)
 416   def reduce(x): return MPReduce(x)
 417   def __truediv__(me, you): return IntRat(me, you)
 418   def __rtruediv__(me, you): return IntRat(you, me)
 419   __div__ = __truediv__
 420   __rdiv__ = __rtruediv__
 421   _repr_pretty_ = _pp_str
 422 _augment(MP, _tmp)
 423
 424 class _tmp:
 425   def zerop(x): return x == 0
 426   def reduce(x): return GFReduce(x)
 427   def trace(x, y): return x.reduce().trace(y)
 428   def halftrace(x, y): return x.reduce().halftrace(y)
 429   def modsqrt(x, y): return x.reduce().sqrt(y)
 430   def quadsolve(x, y): return x.reduce().quadsolve(y)
 431   def __truediv__(me, you): return GFRat(me, you)
 432   def __rtruediv__(me, you): return GFRat(you, me)
 433   __div__ = __truediv__
 434   __rdiv__ = __rtruediv__
 435   _repr_pretty_ = _pp_str
 436 _augment(GF, _tmp)
 437
 438 class _tmp:
 439   def product(*arg):
 440     'product(ITERABLE) or product(I, ...) -> PRODUCT'
 441     return MPMul(*arg).done()
 442   product = staticmethod(product)
 443 _augment(MPMul, _tmp)
 444
 445 ###--------------------------------------------------------------------------
 446 ### Abstract fields.
 447
 448 class _tmp:
 449   def fromstring(str): return _checkend(Field.parse(str))
 450   fromstring = staticmethod(fromstring)
 451 _augment(Field, _tmp)
 452
 453 class _tmp:
 454   def __repr__(me): return '%s(%sL)' % (_clsname(me), me.p)
 455   def __hash__(me): return 0x114401de ^ hash(me.p)
 456   def _repr_pretty_(me, pp, cyclep):
 457     ind = _pp_bgroup_tyname(pp, me)
 458     if cyclep: pp.text('...')
 459     else: pp.pretty(me.p)
 460     pp.end_group(ind, ')')
 461   def ec(me, a, b): return ECPrimeProjCurve(me, a, b)
 462 _augment(PrimeField, _tmp)
 463
 464 class _tmp:
 465   def __repr__(me): return '%s(%#xL)' % (_clsname(me), me.p)
 466   def ec(me, a, b): return ECBinProjCurve(me, a, b)
 467   def _repr_pretty_(me, pp, cyclep):
 468     ind = _pp_bgroup_tyname(pp, me)
 469     if cyclep: pp.text('...')
 470     else: pp.text('%#x' % me.p)
 471     pp.end_group(ind, ')')
 472 _augment(BinField, _tmp)
 473
 474 class _tmp:
 475   def __hash__(me): return 0x23e4701c ^ hash(me.p)
 476 _augment(BinPolyField, _tmp)
 477
 478 class _tmp:
 479   def __hash__(me):
 480     h = 0x9a7d6240
 481     h ^=   hash(me.p)
 482     h ^= 2*hash(me.beta) & 0xffffffff
 483     return h
 484 _augment(BinNormField, _tmp)
 485
 486 class _tmp:
 487   def __str__(me): return str(me.value)
 488   def __repr__(me): return '%s(%s)' % (repr(me.field), repr(me.value))
 489   _repr_pretty_ = _pp_str
 490 _augment(FE, _tmp)
 491
 492 ###--------------------------------------------------------------------------
 493 ### Elliptic curves.
 494
 495 class _tmp:
 496   def __repr__(me):
 497     return '%s(%r, %s, %s)' % (_clsname(me), me.field, me.a, me.b)
 498   def _repr_pretty_(me, pp, cyclep):
 499     ind = _pp_bgroup_tyname(pp, me)
 500     if cyclep:
 501       pp.text('...')
 502     else:
 503       pp.pretty(me.field); pp.text(','); pp.breakable()
 504       pp.pretty(me.a); pp.text(','); pp.breakable()
 505       pp.pretty(me.b)
 506     pp.end_group(ind, ')')
 507   def frombuf(me, s):
 508     return ecpt.frombuf(me, s)
 509   def fromraw(me, s):
 510     return ecpt.fromraw(me, s)
 511   def pt(me, *args):
 512     return me(*args)
 513 _augment(ECCurve, _tmp)
 514
 515 class _tmp:
 516   def __hash__(me):
 517     h = 0x6751d341
 518     h ^=   hash(me.field)
 519     h ^= 2*hash(me.a) ^ 0xffffffff
 520     h ^= 5*hash(me.b) ^ 0xffffffff
 521     return h
 522 _augment(ECPrimeCurve, _tmp)
 523
 524 class _tmp:
 525   def __hash__(me):
 526     h = 0x2ac203c5
 527     h ^=   hash(me.field)
 528     h ^= 2*hash(me.a) ^ 0xffffffff
 529     h ^= 5*hash(me.b) ^ 0xffffffff
 530     return h
 531 _augment(ECBinCurve, _tmp)
 532
 533 class _tmp:
 534   def __repr__(me):
 535     if not me: return '%s()' % _clsname(me)
 536     return '%s(%s, %s)' % (_clsname(me), me.ix, me.iy)
 537   def __str__(me):
 538     if not me: return 'inf'
 539     return '(%s, %s)' % (me.ix, me.iy)
 540   def _repr_pretty_(me, pp, cyclep):
 541     if cyclep:
 542       pp.text('...')
 543     elif not me:
 544       pp.text('inf')
 545     else:
 546       ind = _pp_bgroup(pp, '(')
 547       pp.pretty(me.ix); pp.text(','); pp.breakable()
 548       pp.pretty(me.iy)
 549       pp.end_group(ind, ')')
 550 _augment(ECPt, _tmp)
 551
 552 class _tmp:
 553   def __repr__(me):
 554     return '%s(curve = %r, G = %r, r = %s, h = %s)' % \
 555            (_clsname(me), me.curve, me.G, me.r, me.h)
 556   def _repr_pretty_(me, pp, cyclep):
 557     ind = _pp_bgroup_tyname(pp, me)
 558     if cyclep:
 559       pp.text('...')
 560     else:
 561       _pp_kv(pp, 'curve', me.curve); pp.text(','); pp.breakable()
 562       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 563       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 564       _pp_kv(pp, 'h', me.h)
 565     pp.end_group(ind, ')')
 566   def __hash__(me):
 567     h = 0x9bedb8de
 568     h ^=   hash(me.curve)
 569     h ^= 2*hash(me.G) & 0xffffffff
 570     return h
 571   def group(me):
 572     return ECGroup(me)
 573 _augment(ECInfo, _tmp)
 574
 575 class _tmp:
 576   def __repr__(me):
 577     if not me: return '%r()' % (me.curve)
 578     return '%r(%s, %s)' % (me.curve, me.x, me.y)
 579   def __str__(me):
 580     if not me: return 'inf'
 581     return '(%s, %s)' % (me.x, me.y)
 582   def _repr_pretty_(me, pp, cyclep):
 583     if cyclep:
 584       pp.text('...')
 585     elif not me:
 586       pp.text('inf')
 587     else:
 588       ind = _pp_bgroup(pp, '(')
 589       pp.pretty(me.x); pp.text(','); pp.breakable()
 590       pp.pretty(me.y)
 591       pp.end_group(ind, ')')
 592 _augment(ECPtCurve, _tmp)
 593
 594 ###--------------------------------------------------------------------------
 595 ### Key sizes.
 596
 597 class _tmp:
 598   def __repr__(me): return '%s(%d)' % (_clsname(me), me.default)
 599   def check(me, sz): return True
 600   def best(me, sz): return sz
 601   def pad(me, sz): return sz
 602 _augment(KeySZAny, _tmp)
 603
 604 class _tmp:
 605   def __repr__(me):
 606     return '%s(%d, %d, %d, %d)' % \
 607            (_clsname(me), me.default, me.min, me.max, me.mod)
 608   def _repr_pretty_(me, pp, cyclep):
 609     ind = _pp_bgroup_tyname(pp, me)
 610     if cyclep:
 611       pp.text('...')
 612     else:
 613       pp.pretty(me.default); pp.text(','); pp.breakable()
 614       pp.pretty(me.min); pp.text(','); pp.breakable()
 615       pp.pretty(me.max); pp.text(','); pp.breakable()
 616       pp.pretty(me.mod)
 617     pp.end_group(ind, ')')
 618   def check(me, sz): return me.min <= sz <= me.max and sz%me.mod == 0
 619   def best(me, sz):
 620     if sz < me.min: raise ValueError, 'key too small'
 621     elif sz > me.max: return me.max
 622     else: return sz - sz%me.mod
 623   def pad(me, sz):
 624     if sz > me.max: raise ValueError, 'key too large'
 625     elif sz < me.min: return me.min
 626     else: sz += me.mod; return sz - sz%me.mod
 627 _augment(KeySZRange, _tmp)
 628
 629 class _tmp:
 630   def __repr__(me): return '%s(%d, %s)' % (_clsname(me), me.default, me.set)
 631   def _repr_pretty_(me, pp, cyclep):
 632     ind = _pp_bgroup_tyname(pp, me)
 633     if cyclep:
 634       pp.text('...')
 635     else:
 636       pp.pretty(me.default); pp.text(','); pp.breakable()
 637       ind1 = _pp_bgroup(pp, '{')
 638       _pp_commas(pp, pp.pretty, me.set)
 639       pp.end_group(ind1, '}')
 640     pp.end_group(ind, ')')
 641   def check(me, sz): return sz in me.set
 642   def best(me, sz):
 643     found = -1
 644     for i in me.set:
 645       if found < i <= sz: found = i
 646     if found < 0: raise ValueError, 'key too small'
 647     return found
 648   def pad(me, sz):
 649     found = -1
 650     for i in me.set:
 651       if sz <= i and (found == -1 or i < found): found = i
 652     if found < 0: raise ValueError, 'key too large'
 653     return found
 654 _augment(KeySZSet, _tmp)
 655
 656 ###--------------------------------------------------------------------------
 657 ### Key data objects.
 658
 659 class _tmp:
 660   def __repr__(me): return '%s(%r)' % (_clsname(me), me.name)
 661 _augment(KeyFile, _tmp)
 662
 663 class _tmp:
 664   def __repr__(me): return '%s(%r)' % (_clsname(me), me.fulltag)
 665 _augment(Key, _tmp)
 666
 667 class _tmp:
 668   def __repr__(me):
 669     return '%s({%s})' % (_clsname(me),
 670                          ', '.join(['%r: %r' % kv for kv in me.iteritems()]))
 671   def _repr_pretty_(me, pp, cyclep):
 672     ind = _pp_bgroup_tyname(pp, me)
 673     if cyclep: pp.text('...')
 674     else: _pp_dict(pp, me.iteritems())
 675     pp.end_group(ind, ')')
 676 _augment(KeyAttributes, _tmp)
 677
 678 class _tmp:
 679   def __repr__(me):
 680     return '%s(%s, %r)' % (_clsname(me),
 681                            _repr_secret(me._guts(),
 682                                         not (me.flags & KF_NONSECRET)),
 683                            me.writeflags(me.flags))
 684   def _repr_pretty_(me, pp, cyclep):
 685     ind = _pp_bgroup_tyname(pp, me)
 686     if cyclep:
 687       pp.text('...')
 688     else:
 689       _pp_secret(pp, me._guts(), not (me.flags & KF_NONSECRET))
 690       pp.text(','); pp.breakable()
 691       pp.pretty(me.writeflags(me.flags))
 692     pp.end_group(ind, ')')
 693 _augment(KeyData, _tmp)
 694
 695 class _tmp:
 696   def _guts(me): return me.bin
 697 _augment(KeyDataBinary, _tmp)
 698
 699 class _tmp:
 700   def _guts(me): return me.ct
 701 _augment(KeyDataEncrypted, _tmp)
 702
 703 class _tmp:
 704   def _guts(me): return me.mp
 705 _augment(KeyDataMP, _tmp)
 706
 707 class _tmp:
 708   def _guts(me): return me.str
 709 _augment(KeyDataString, _tmp)
 710
 711 class _tmp:
 712   def _guts(me): return me.ecpt
 713 _augment(KeyDataECPt, _tmp)
 714
 715 class _tmp:
 716   def __repr__(me):
 717     return '%s({%s})' % (_clsname(me),
 718                          ', '.join(['%r: %r' % kv for kv in me.iteritems()]))
 719   def _repr_pretty_(me, pp, cyclep):
 720     ind = _pp_bgroup_tyname(pp, me, '({ ')
 721     if cyclep: pp.text('...')
 722     else: _pp_dict(pp, me.iteritems())
 723     pp.end_group(ind, ' })')
 724 _augment(KeyDataStructured, _tmp)
 725
 726 ###--------------------------------------------------------------------------
 727 ### Abstract groups.
 728
 729 class _tmp:
 730   def __repr__(me):
 731     return '%s(p = %s, r = %s, g = %s)' % (_clsname(me), me.p, me.r, me.g)
 732   def _repr_pretty_(me, pp, cyclep):
 733     ind = _pp_bgroup_tyname(pp, me)
 734     if cyclep:
 735       pp.text('...')
 736     else:
 737       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 738       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 739       _pp_kv(pp, 'g', me.g)
 740     pp.end_group(ind, ')')
 741 _augment(FGInfo, _tmp)
 742
 743 class _tmp:
 744   def group(me): return PrimeGroup(me)
 745 _augment(DHInfo, _tmp)
 746
 747 class _tmp:
 748   def group(me): return BinGroup(me)
 749 _augment(BinDHInfo, _tmp)
 750
 751 class _tmp:
 752   def __repr__(me):
 753     return '%s(%r)' % (_clsname(me), me.info)
 754   def _repr_pretty_(me, pp, cyclep):
 755     ind = _pp_bgroup_tyname(pp, me)
 756     if cyclep: pp.text('...')
 757     else: pp.pretty(me.info)
 758     pp.end_group(ind, ')')
 759 _augment(Group, _tmp)
 760
 761 class _tmp:
 762   def __hash__(me):
 763     info = me.info
 764     h = 0xbce3cfe6
 765     h ^=   hash(info.p)
 766     h ^= 2*hash(info.r) & 0xffffffff
 767     h ^= 5*hash(info.g) & 0xffffffff
 768     return h
 769   def _get_geval(me, x): return MP(x)
 770 _augment(PrimeGroup, _tmp)
 771
 772 class _tmp:
 773   def __hash__(me):
 774     info = me.info
 775     h = 0x80695949
 776     h ^=   hash(info.p)
 777     h ^= 2*hash(info.r) & 0xffffffff
 778     h ^= 5*hash(info.g) & 0xffffffff
 779     return h
 780   def _get_geval(me, x): return GF(x)
 781 _augment(BinGroup, _tmp)
 782
 783 class _tmp:
 784   def __hash__(me): return 0x0ec23dab ^ hash(me.info)
 785   def _get_geval(me, x): return x.toec()
 786 _augment(ECGroup, _tmp)
 787
 788 class _tmp:
 789   def __repr__(me):
 790     return '%r(%r)' % (me.group, str(me))
 791   def _repr_pretty_(me, pp, cyclep):
 792     pp.pretty(type(me)._get_geval(me))
 793 _augment(GE, _tmp)
 794
 795 ###--------------------------------------------------------------------------
 796 ### RSA encoding techniques.
 797
 798 class PKCS1Crypt (object):
 799   def __init__(me, ep = '', rng = rand):
 800     me.ep = ep
 801     me.rng = rng
 802   def encode(me, msg, nbits):
 803     return _base._p1crypt_encode(msg, nbits, me.ep, me.rng)
 804   def decode(me, ct, nbits):
 805     return _base._p1crypt_decode(ct, nbits, me.ep, me.rng)
 806
 807 class PKCS1Sig (object):
 808   def __init__(me, ep = '', rng = rand):
 809     me.ep = ep
 810     me.rng = rng
 811   def encode(me, msg, nbits):
 812     return _base._p1sig_encode(msg, nbits, me.ep, me.rng)
 813   def decode(me, msg, sig, nbits):
 814     return _base._p1sig_decode(msg, sig, nbits, me.ep, me.rng)
 815
 816 class OAEP (object):
 817   def __init__(me, mgf = sha_mgf, hash = sha, ep = '', rng = rand):
 818     me.mgf = mgf
 819     me.hash = hash
 820     me.ep = ep
 821     me.rng = rng
 822   def encode(me, msg, nbits):
 823     return _base._oaep_encode(msg, nbits, me.mgf, me.hash, me.ep, me.rng)
 824   def decode(me, ct, nbits):
 825     return _base._oaep_decode(ct, nbits, me.mgf, me.hash, me.ep, me.rng)
 826
 827 class PSS (object):
 828   def __init__(me, mgf = sha_mgf, hash = sha, saltsz = None, rng = rand):
 829     me.mgf = mgf
 830     me.hash = hash
 831     if saltsz is None:
 832       saltsz = hash.hashsz
 833     me.saltsz = saltsz
 834     me.rng = rng
 835   def encode(me, msg, nbits):
 836     return _base._pss_encode(msg, nbits, me.mgf, me.hash, me.saltsz, me.rng)
 837   def decode(me, msg, sig, nbits):
 838     return _base._pss_decode(msg, sig, nbits,
 839                              me.mgf, me.hash, me.saltsz, me.rng)
 840
 841 class _tmp:
 842   def encrypt(me, msg, enc):
 843     return me.pubop(enc.encode(msg, me.n.nbits))
 844   def verify(me, msg, sig, enc):
 845     if msg is None: return enc.decode(msg, me.pubop(sig), me.n.nbits)
 846     try:
 847       x = enc.decode(msg, me.pubop(sig), me.n.nbits)
 848       return x is None or x == msg
 849     except ValueError:
 850       return False
 851   def __repr__(me):
 852     return '%s(n = %r, e = %r)' % (_clsname(me), me.n, me.e)
 853   def _repr_pretty_(me, pp, cyclep):
 854     ind = _pp_bgroup_tyname(pp, me)
 855     if cyclep:
 856       pp.text('...')
 857     else:
 858       _pp_kv(pp, 'n', me.n); pp.text(','); pp.breakable()
 859       _pp_kv(pp, 'e', me.e)
 860     pp.end_group(ind, ')')
 861 _augment(RSAPub, _tmp)
 862
 863 class _tmp:
 864   def decrypt(me, ct, enc): return enc.decode(me.privop(ct), me.n.nbits)
 865   def sign(me, msg, enc): return me.privop(enc.encode(msg, me.n.nbits))
 866   def __repr__(me):
 867     return '%s(n = %r, e = %r, d = %s, ' \
 868       'p = %s, q = %s, dp = %s, dq = %s, q_inv = %s)' % \
 869       (_clsname(me), me.n, me.e,
 870        _repr_secret(me.d), _repr_secret(me.p), _repr_secret(me.q),
 871        _repr_secret(me.dp), _repr_secret(me.dq), _repr_secret(me.q_inv))
 872   def _repr_pretty_(me, pp, cyclep):
 873     ind = _pp_bgroup_tyname(pp, me)
 874     if cyclep:
 875       pp.text('...')
 876     else:
 877       _pp_kv(pp, 'n', me.n); pp.text(','); pp.breakable()
 878       _pp_kv(pp, 'e', me.e); pp.text(','); pp.breakable()
 879       _pp_kv(pp, 'd', me.d, secretp = True); pp.text(','); pp.breakable()
 880       _pp_kv(pp, 'p', me.p, secretp = True); pp.text(','); pp.breakable()
 881       _pp_kv(pp, 'q', me.q, secretp = True); pp.text(','); pp.breakable()
 882       _pp_kv(pp, 'dp', me.dp, secretp = True); pp.text(','); pp.breakable()
 883       _pp_kv(pp, 'dq', me.dq, secretp = True); pp.text(','); pp.breakable()
 884       _pp_kv(pp, 'q_inv', me.q_inv, secretp = True)
 885     pp.end_group(ind, ')')
 886 _augment(RSAPriv, _tmp)
 887
 888 ###--------------------------------------------------------------------------
 889 ### DSA and related schemes.
 890
 891 class _tmp:
 892   def __repr__(me): return '%s(G = %r, p = %r, hash = %r)' % \
 893         (_clsname(me), me.G, me.p, me.hash)
 894   def _repr_pretty_(me, pp, cyclep):
 895     ind = _pp_bgroup_tyname(pp, me)
 896     if cyclep:
 897       pp.text('...')
 898     else:
 899       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 900       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 901       _pp_kv(pp, 'hash', me.hash)
 902     pp.end_group(ind, ')')
 903 _augment(DSAPub, _tmp)
 904 _augment(KCDSAPub, _tmp)
 905
 906 class _tmp:
 907   def __repr__(me): return '%s(G = %r, u = %s, p = %r, hash = %r)' % \
 908       (_clsname(me), me.G, _repr_secret(me.u), me.p, me.hash)
 909   def _repr_pretty_(me, pp, cyclep):
 910     ind = _pp_bgroup_tyname(pp, me)
 911     if cyclep:
 912       pp.text('...')
 913     else:
 914       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 915       _pp_kv(pp, 'u', me.u, True); pp.text(','); pp.breakable()
 916       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 917       _pp_kv(pp, 'hash', me.hash)
 918     pp.end_group(ind, ')')
 919 _augment(DSAPriv, _tmp)
 920 _augment(KCDSAPriv, _tmp)
 921
 922 ###--------------------------------------------------------------------------
 923 ### Bernstein's elliptic curve crypto and related schemes.
 924
 925 X25519_BASE = MP(9).storel(32)
 926 X448_BASE = MP(5).storel(56)
 927
 928 Z128 = ByteString.zero(16)
 929
 930 class _BasePub (object):
 931   def __init__(me, pub, *args, **kw):
 932     if not me._PUBSZ.check(len(pub)): raise ValueError, 'bad public key'
 933     super(_BasePub, me).__init__(*args, **kw)
 934     me.pub = pub
 935   def __repr__(me): return '%s(pub = %r)' % (_clsname(me), me.pub)
 936   def _pp(me, pp): _pp_kv(pp, 'pub', me.pub)
 937   def _repr_pretty_(me, pp, cyclep):
 938     ind = _pp_bgroup_tyname(pp, me)
 939     if cyclep: pp.text('...')
 940     else: me._pp(pp)
 941     pp.end_group(ind, ')')
 942
 943 class _BasePriv (object):
 944   def __init__(me, priv, pub = None, *args, **kw):
 945     if not me._KEYSZ.check(len(priv)): raise ValueError, 'bad private key'
 946     if pub is None: pub = me._pubkey(priv)
 947     super(_BasePriv, me).__init__(pub = pub, *args, **kw)
 948     me.priv = priv
 949   @classmethod
 950   def generate(cls, rng = rand):
 951     return cls(rng.block(cls._KEYSZ.default))
 952   def __repr__(me):
 953     return '%s(priv = %d, pub = %r)' % \
 954         (_clsname(me), _repr_secret(me.priv), me.pub)
 955   def _pp(me, pp):
 956     _pp_kv(pp, 'priv', me.priv, secretp = True); pp.text(','); pp.breakable()
 957     super(_BasePriv, me)._pp(pp)
 958
 959 class _XDHPub (_BasePub):  pass
 960
 961 class _XDHPriv (_BasePriv):
 962   def _pubkey(me, priv): return me._op(priv, me._BASE)
 963   def agree(me, you): return me._op(me.priv, you.pub)
 964   def boxkey(me, recip): return me._hashkey(me.agree(recip))
 965   def box(me, recip, n, m): return secret_box(me.boxkey(recip), n, m)
 966   def unbox(me, recip, n, c): return secret_unbox(me.boxkey(recip), n, c)
 967
 968 class X25519Pub (_XDHPub):
 969   _PUBSZ = KeySZSet(X25519_PUBSZ)
 970   _BASE = X25519_BASE
 971
 972 class X25519Priv (_XDHPriv, X25519Pub):
 973   _KEYSZ = KeySZSet(X25519_KEYSZ)
 974   def _op(me, k, X): return x25519(k, X)
 975   def _hashkey(me, z): return hsalsa20_prf(z, Z128)
 976
 977 class X448Pub (_XDHPub):
 978   _PUBSZ = KeySZSet(X448_PUBSZ)
 979   _BASE = X448_BASE
 980
 981 class X448Priv (_XDHPriv, X448Pub):
 982   _KEYSZ = KeySZSet(X448_KEYSZ)
 983   def _op(me, k, X): return x448(k, X)
 984   def _hashkey(me, z): return Shake256().hash(z).done(salsa20.keysz.default)
 985
 986 class _EdDSAPub (_BasePub):
 987   def beginhash(me): return me._HASH()
 988   def endhash(me, h): return h.done()
 989
 990 class _EdDSAPriv (_BasePriv, _EdDSAPub):
 991   pass
 992
 993 class Ed25519Pub (_EdDSAPub):
 994   _PUBSZ = KeySZSet(ED25519_PUBSZ)
 995   _HASH = sha512
 996   def verify(me, msg, sig, **kw):
 997     return ed25519_verify(me.pub, msg, sig, **kw)
 998
 999 class Ed25519Priv (_EdDSAPriv, Ed25519Pub):
1000   _KEYSZ = KeySZAny(ED25519_KEYSZ)
1001   def _pubkey(me, priv): return ed25519_pubkey(priv)
1002   def sign(me, msg, **kw):
1003     return ed25519_sign(me.priv, msg, pub = me.pub, **kw)
1004
1005 class Ed448Pub (_EdDSAPub):
1006   _PUBSZ = KeySZSet(ED448_PUBSZ)
1007   _HASH = shake256
1008   def verify(me, msg, sig, **kw):
1009     return ed448_verify(me.pub, msg, sig, **kw)
1010
1011 class Ed448Priv (_EdDSAPriv, Ed448Pub):
1012   _KEYSZ = KeySZAny(ED448_KEYSZ)
1013   def _pubkey(me, priv): return ed448_pubkey(priv)
1014   def sign(me, msg, **kw):
1015     return ed448_sign(me.priv, msg, pub = me.pub, **kw)
1016
1017 ###--------------------------------------------------------------------------
1018 ### Built-in named curves and prime groups.
1019
1020 class _groupmap (object):
1021   def __init__(me, map, nth):
1022     me.map = map
1023     me.nth = nth
1024     me._n = max(map.values()) + 1
1025     me.i = me._n*[None]
1026   def __repr__(me):
1027     return '{%s}' % ', '.join(['%r: %r' % kv for kv in me.iteritems()])
1028   def _repr_pretty_(me, pp, cyclep):
1029     ind = _pp_bgroup(pp, '{ ')
1030     if cyclep: pp.text('...')
1031     else: _pp_dict(pp, me.iteritems())
1032     pp.end_group(ind, ' }')
1033   def __len__(me):
1034     return me._n
1035   def __contains__(me, k):
1036     return k in me.map
1037   def __getitem__(me, k):
1038     i = me.map[k]
1039     if me.i[i] is None:
1040       me.i[i] = me.nth(i)
1041     return me.i[i]
1042   def __setitem__(me, k, v):
1043     raise TypeError, "immutable object"
1044   def __iter__(me):
1045     return iter(me.map)
1046   def iterkeys(me):
1047     return iter(me.map)
1048   def itervalues(me):
1049     for k in me:
1050       yield me[k]
1051   def iteritems(me):
1052     for k in me:
1053       yield k, me[k]
1054   def keys(me):
1055     return [k for k in me]
1056   def values(me):
1057     return [me[k] for k in me]
1058   def items(me):
1059     return [(k, me[k]) for k in me]
1060 eccurves = _groupmap(_base._eccurves, ECInfo._curven)
1061 primegroups = _groupmap(_base._pgroups, DHInfo._groupn)
1062 bingroups = _groupmap(_base._bingroups, BinDHInfo._groupn)
1063
1064 ###--------------------------------------------------------------------------
1065 ### Prime number generation.
1066
1067 class PrimeGenEventHandler (object):
1068   def pg_begin(me, ev):
1069     return me.pg_try(ev)
1070   def pg_done(me, ev):
1071     return PGEN_DONE
1072   def pg_abort(me, ev):
1073     return PGEN_TRY
1074   def pg_fail(me, ev):
1075     return PGEN_TRY
1076   def pg_pass(me, ev):
1077     return PGEN_TRY
1078
1079 class SophieGermainStepJump (object):
1080   def pg_begin(me, ev):
1081     me.lf = PrimeFilter(ev.x)
1082     me.hf = me.lf.muladd(2, 1)
1083     return me.cont(ev)
1084   def pg_try(me, ev):
1085     me.step()
1086     return me.cont(ev)
1087   def cont(me, ev):
1088     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
1089       me.step()
1090     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
1091       return PGEN_ABORT
1092     ev.x = me.lf.x
1093     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
1094       return PGEN_DONE
1095     return PGEN_TRY
1096   def pg_done(me, ev):
1097     del me.lf
1098     del me.hf
1099
1100 class SophieGermainStepper (SophieGermainStepJump):
1101   def __init__(me, step):
1102     me.lstep = step;
1103     me.hstep = 2 * step
1104   def step(me):
1105     me.lf.step(me.lstep)
1106     me.hf.step(me.hstep)
1107
1108 class SophieGermainJumper (SophieGermainStepJump):
1109   def __init__(me, jump):
1110     me.ljump = PrimeFilter(jump);
1111     me.hjump = me.ljump.muladd(2, 0)
1112   def step(me):
1113     me.lf.jump(me.ljump)
1114     me.hf.jump(me.hjump)
1115   def pg_done(me, ev):
1116     del me.ljump
1117     del me.hjump
1118     SophieGermainStepJump.pg_done(me, ev)
1119
1120 class SophieGermainTester (object):
1121   def __init__(me):
1122     pass
1123   def pg_begin(me, ev):
1124     me.lr = RabinMiller(ev.x)
1125     me.hr = RabinMiller(2 * ev.x + 1)
1126   def pg_try(me, ev):
1127     lst = me.lr.test(ev.rng.range(me.lr.x))
1128     if lst != PGEN_PASS and lst != PGEN_DONE:
1129       return lst
1130     rst = me.hr.test(ev.rng.range(me.hr.x))
1131     if rst != PGEN_PASS and rst != PGEN_DONE:
1132       return rst
1133     if lst == PGEN_DONE and rst == PGEN_DONE:
1134       return PGEN_DONE
1135     return PGEN_PASS
1136   def pg_done(me, ev):
1137     del me.lr
1138     del me.hr
1139
1140 class PrimitiveStepper (PrimeGenEventHandler):
1141   def __init__(me):
1142     pass
1143   def pg_try(me, ev):
1144     ev.x = me.i.next()
1145     return PGEN_TRY
1146   def pg_begin(me, ev):
1147     me.i = iter(smallprimes)
1148     return me.pg_try(ev)
1149
1150 class PrimitiveTester (PrimeGenEventHandler):
1151   def __init__(me, mod, hh = [], exp = None):
1152     me.mod = MPMont(mod)
1153     me.exp = exp
1154     me.hh = hh
1155   def pg_try(me, ev):
1156     x = ev.x
1157     if me.exp is not None:
1158       x = me.mod.exp(x, me.exp)
1159       if x == 1: return PGEN_FAIL
1160     for h in me.hh:
1161       if me.mod.exp(x, h) == 1: return PGEN_FAIL
1162     ev.x = x
1163     return PGEN_DONE
1164
1165 class SimulStepper (PrimeGenEventHandler):
1166   def __init__(me, mul = 2, add = 1, step = 2):
1167     me.step = step
1168     me.mul = mul
1169     me.add = add
1170   def _stepfn(me, step):
1171     if step <= 0:
1172       raise ValueError, 'step must be positive'
1173     if step <= MPW_MAX:
1174       return lambda f: f.step(step)
1175     j = PrimeFilter(step)
1176     return lambda f: f.jump(j)
1177   def pg_begin(me, ev):
1178     x = ev.x
1179     me.lf = PrimeFilter(x)
1180     me.hf = PrimeFilter(x * me.mul + me.add)
1181     me.lstep = me._stepfn(me.step)
1182     me.hstep = me._stepfn(me.step * me.mul)
1183     SimulStepper._cont(me, ev)
1184   def pg_try(me, ev):
1185     me._step()
1186     me._cont(ev)
1187   def _step(me):
1188     me.lstep(me.lf)
1189     me.hstep(me.hf)
1190   def _cont(me, ev):
1191     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
1192       me._step()
1193     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
1194       return PGEN_ABORT
1195     ev.x = me.lf.x
1196     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
1197       return PGEN_DONE
1198     return PGEN_TRY
1199   def pg_done(me, ev):
1200     del me.lf
1201     del me.hf
1202     del me.lstep
1203     del me.hstep
1204
1205 class SimulTester (PrimeGenEventHandler):
1206   def __init__(me, mul = 2, add = 1):
1207     me.mul = mul
1208     me.add = add
1209   def pg_begin(me, ev):
1210     x = ev.x
1211     me.lr = RabinMiller(x)
1212     me.hr = RabinMiller(x * me.mul + me.add)
1213   def pg_try(me, ev):
1214     lst = me.lr.test(ev.rng.range(me.lr.x))
1215     if lst != PGEN_PASS and lst != PGEN_DONE:
1216       return lst
1217     rst = me.hr.test(ev.rng.range(me.hr.x))
1218     if rst != PGEN_PASS and rst != PGEN_DONE:
1219       return rst
1220     if lst == PGEN_DONE and rst == PGEN_DONE:
1221       return PGEN_DONE
1222     return PGEN_PASS
1223   def pg_done(me, ev):
1224     del me.lr
1225     del me.hr
1226
1227 def sgprime(start, step = 2, name = 'p', event = pgen_nullev, nsteps = 0):
1228   start = MP(start)
1229   return pgen(start, name, SimulStepper(step = step), SimulTester(), event,
1230               nsteps, RabinMiller.iters(start.nbits))
1231
1232 def findprimitive(mod, hh = [], exp = None, name = 'g', event = pgen_nullev):
1233   return pgen(0, name, PrimitiveStepper(), PrimitiveTester(mod, hh, exp),
1234               event, 0, 1)
1235
1236 def kcdsaprime(pbits, qbits, rng = rand,
1237                event = pgen_nullev, name = 'p', nsteps = 0):
1238   hbits = pbits - qbits
1239   h = pgen(rng.mp(hbits, 1), name + ' [h]',
1240            PrimeGenStepper(2), PrimeGenTester(),
1241            event, nsteps, RabinMiller.iters(hbits))
1242   q = pgen(rng.mp(qbits, 1), name, SimulStepper(2 * h, 1, 2),
1243            SimulTester(2 * h, 1), event, nsteps, RabinMiller.iters(qbits))
1244   p = 2 * q * h + 1
1245   return p, q, h
1246
1247 #----- That's all, folks ----------------------------------------------------