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, 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 ### Hashing.
 198
 199 class _tmp:
 200   def check(me, h):
 201     hh = me.done()
 202     return ctstreq(h, hh)
 203 _augment(GHash, _tmp)
 204 _augment(Poly1305Hash, _tmp)
 205
 206 class _HashBase (object):
 207   ## The standard hash methods.  Assume that `hash' is defined and returns
 208   ## the receiver.
 209   def _check_range(me, n, max):
 210     if not (0 <= n <= max): raise OverflowError("out of range")
 211   def hashu8(me, n):
 212     me._check_range(n, 0xff)
 213     return me.hash(_pack('B', n))
 214   def hashu16l(me, n):
 215     me._check_range(n, 0xffff)
 216     return me.hash(_pack('<H', n))
 217   def hashu16b(me, n):
 218     me._check_range(n, 0xffff)
 219     return me.hash(_pack('>H', n))
 220   hashu16 = hashu16b
 221   def hashu32l(me, n):
 222     me._check_range(n, 0xffffffff)
 223     return me.hash(_pack('<L', n))
 224   def hashu32b(me, n):
 225     me._check_range(n, 0xffffffff)
 226     return me.hash(_pack('>L', n))
 227   hashu32 = hashu32b
 228   def hashu64l(me, n):
 229     me._check_range(n, 0xffffffffffffffff)
 230     return me.hash(_pack('<Q', n))
 231   def hashu64b(me, n):
 232     me._check_range(n, 0xffffffffffffffff)
 233     return me.hash(_pack('>Q', n))
 234   hashu64 = hashu64b
 235   def hashbuf8(me, s): return me.hashu8(len(s)).hash(s)
 236   def hashbuf16l(me, s): return me.hashu16l(len(s)).hash(s)
 237   def hashbuf16b(me, s): return me.hashu16b(len(s)).hash(s)
 238   hashbuf16 = hashbuf16b
 239   def hashbuf32l(me, s): return me.hashu32l(len(s)).hash(s)
 240   def hashbuf32b(me, s): return me.hashu32b(len(s)).hash(s)
 241   hashbuf32 = hashbuf32b
 242   def hashbuf64l(me, s): return me.hashu64l(len(s)).hash(s)
 243   def hashbuf64b(me, s): return me.hashu64b(len(s)).hash(s)
 244   hashbuf64 = hashbuf64b
 245   def hashstrz(me, s): return me.hash(s).hashu8(0)
 246
 247 class _ShakeBase (_HashBase):
 248
 249   ## Python gets really confused if I try to augment `__new__' on native
 250   ## classes, so wrap and delegate.  Sorry.
 251   def __init__(me, perso = '', *args, **kw):
 252     super(_ShakeBase, me).__init__(*args, **kw)
 253     me._h = me._SHAKE(perso = perso, func = me._FUNC)
 254
 255   ## Delegate methods...
 256   def copy(me): new = me.__class__._bare_new(); new._copy(me); return new
 257   def _copy(me, other): me._h = other._h.copy()
 258   def hash(me, m): me._h.hash(m); return me
 259   def xof(me): me._h.xof(); return me
 260   def get(me, n): return me._h.get(n)
 261   def mask(me, m): return me._h.mask(m)
 262   def done(me, n): return me._h.done(n)
 263   def check(me, h): return ctstreq(h, me.done(len(h)))
 264   @property
 265   def state(me): return me._h.state
 266   @property
 267   def buffered(me): return me._h.buffered
 268   @property
 269   def rate(me): return me._h.rate
 270   @classmethod
 271   def _bare_new(cls): return cls()
 272
 273 class _tmp:
 274   def check(me, h):
 275     return ctstreq(h, me.done(len(h)))
 276   def leftenc(me, n):
 277     nn = MP(n).storeb()
 278     return me.hashu8(len(nn)).hash(nn)
 279   def rightenc(me, n):
 280     nn = MP(n).storeb()
 281     return me.hash(nn).hashu8(len(nn))
 282   def stringenc(me, str):
 283     return me.leftenc(8*len(str)).hash(str)
 284   def bytepad_before(me):
 285     return me.leftenc(me.rate)
 286   def bytepad_after(me):
 287     if me.buffered: me.hash(me._Z[:me.rate - me.buffered])
 288     return me
 289   @_ctxmgr
 290   def bytepad(me):
 291     me.bytepad_before()
 292     yield me
 293     me.bytepad_after()
 294 _augment(Shake, _tmp)
 295 _augment(_ShakeBase, _tmp)
 296 Shake._Z = _ShakeBase._Z = ByteString(200*'\0')
 297
 298 class KMAC (_ShakeBase):
 299   _FUNC = 'KMAC'
 300   def __init__(me, k, *arg, **kw):
 301     super(KMAC, me).__init__(*arg, **kw)
 302     with me.bytepad(): me.stringenc(k)
 303   def done(me, n = -1):
 304     if n < 0: n = me._TAGSZ
 305     me.rightenc(8*n)
 306     return super(KMAC, me).done(n)
 307   def xof(me):
 308     me.rightenc(0)
 309     return super(KMAC, me).xof()
 310   @classmethod
 311   def _bare_new(cls): return cls("")
 312
 313 class KMAC128 (KMAC): _SHAKE = Shake128; _TAGSZ = 16
 314 class KMAC256 (KMAC): _SHAKE = Shake256; _TAGSZ = 32
 315
 316 ###--------------------------------------------------------------------------
 317 ### NaCl `secretbox'.
 318
 319 def secret_box(k, n, m):
 320   E = xsalsa20(k).setiv(n)
 321   r = E.enczero(poly1305.keysz.default)
 322   s = E.enczero(poly1305.masksz)
 323   y = E.encrypt(m)
 324   t = poly1305(r)(s).hash(y).done()
 325   return ByteString(t + y)
 326
 327 def secret_unbox(k, n, c):
 328   E = xsalsa20(k).setiv(n)
 329   r = E.enczero(poly1305.keysz.default)
 330   s = E.enczero(poly1305.masksz)
 331   y = c[poly1305.tagsz:]
 332   if not poly1305(r)(s).hash(y).check(c[0:poly1305.tagsz]):
 333     raise ValueError, 'decryption failed'
 334   return E.decrypt(c[poly1305.tagsz:])
 335
 336 ###--------------------------------------------------------------------------
 337 ### Multiprecision integers and binary polynomials.
 338
 339 def _split_rat(x):
 340   if isinstance(x, BaseRat): return x._n, x._d
 341   else: return x, 1
 342 class BaseRat (object):
 343   """Base class implementing fields of fractions over Euclidean domains."""
 344   def __new__(cls, a, b):
 345     a, b = cls.RING(a), cls.RING(b)
 346     q, r = divmod(a, b)
 347     if r == 0: return q
 348     g = b.gcd(r)
 349     me = super(BaseRat, cls).__new__(cls)
 350     me._n = a//g
 351     me._d = b//g
 352     return me
 353   @property
 354   def numer(me): return me._n
 355   @property
 356   def denom(me): return me._d
 357   def __str__(me): return '%s/%s' % (me._n, me._d)
 358   def __repr__(me): return '%s(%s, %s)' % (_clsname(me), me._n, me._d)
 359   _repr_pretty_ = _pp_str
 360
 361   def __add__(me, you):
 362     n, d = _split_rat(you)
 363     return type(me)(me._n*d + n*me._d, d*me._d)
 364   __radd__ = __add__
 365   def __sub__(me, you):
 366     n, d = _split_rat(you)
 367     return type(me)(me._n*d - n*me._d, d*me._d)
 368   def __rsub__(me, you):
 369     n, d = _split_rat(you)
 370     return type(me)(n*me._d - me._n*d, d*me._d)
 371   def __mul__(me, you):
 372     n, d = _split_rat(you)
 373     return type(me)(me._n*n, me._d*d)
 374   __rmul__ = __mul__
 375   def __truediv__(me, you):
 376     n, d = _split_rat(you)
 377     return type(me)(me._n*d, me._d*n)
 378   def __rtruediv__(me, you):
 379     n, d = _split_rat(you)
 380     return type(me)(me._d*n, me._n*d)
 381   __div__ = __truediv__
 382   __rdiv__ = __rtruediv__
 383   def __cmp__(me, you):
 384     n, d = _split_rat(you)
 385     return cmp(me._n*d, n*me._d)
 386   def __rcmp__(me, you):
 387     n, d = _split_rat(you)
 388     return cmp(n*me._d, me._n*d)
 389
 390 class IntRat (BaseRat):
 391   RING = MP
 392
 393 class GFRat (BaseRat):
 394   RING = GF
 395
 396 class _tmp:
 397   def negp(x): return x < 0
 398   def posp(x): return x > 0
 399   def zerop(x): return x == 0
 400   def oddp(x): return x.testbit(0)
 401   def evenp(x): return not x.testbit(0)
 402   def mont(x): return MPMont(x)
 403   def barrett(x): return MPBarrett(x)
 404   def reduce(x): return MPReduce(x)
 405   def __truediv__(me, you): return IntRat(me, you)
 406   def __rtruediv__(me, you): return IntRat(you, me)
 407   __div__ = __truediv__
 408   __rdiv__ = __rtruediv__
 409   _repr_pretty_ = _pp_str
 410 _augment(MP, _tmp)
 411
 412 class _tmp:
 413   def zerop(x): return x == 0
 414   def reduce(x): return GFReduce(x)
 415   def trace(x, y): return x.reduce().trace(y)
 416   def halftrace(x, y): return x.reduce().halftrace(y)
 417   def modsqrt(x, y): return x.reduce().sqrt(y)
 418   def quadsolve(x, y): return x.reduce().quadsolve(y)
 419   def __truediv__(me, you): return GFRat(me, you)
 420   def __rtruediv__(me, you): return GFRat(you, me)
 421   __div__ = __truediv__
 422   __rdiv__ = __rtruediv__
 423   _repr_pretty_ = _pp_str
 424 _augment(GF, _tmp)
 425
 426 class _tmp:
 427   def product(*arg):
 428     'product(ITERABLE) or product(I, ...) -> PRODUCT'
 429     return MPMul(*arg).done()
 430   product = staticmethod(product)
 431 _augment(MPMul, _tmp)
 432
 433 ###--------------------------------------------------------------------------
 434 ### Abstract fields.
 435
 436 class _tmp:
 437   def fromstring(str): return _checkend(Field.parse(str))
 438   fromstring = staticmethod(fromstring)
 439 _augment(Field, _tmp)
 440
 441 class _tmp:
 442   def __repr__(me): return '%s(%sL)' % (_clsname(me), me.p)
 443   def __hash__(me): return 0x114401de ^ hash(me.p)
 444   def _repr_pretty_(me, pp, cyclep):
 445     ind = _pp_bgroup_tyname(pp, me)
 446     if cyclep: pp.text('...')
 447     else: pp.pretty(me.p)
 448     pp.end_group(ind, ')')
 449   def ec(me, a, b): return ECPrimeProjCurve(me, a, b)
 450 _augment(PrimeField, _tmp)
 451
 452 class _tmp:
 453   def __repr__(me): return '%s(%#xL)' % (_clsname(me), me.p)
 454   def ec(me, a, b): return ECBinProjCurve(me, a, b)
 455   def _repr_pretty_(me, pp, cyclep):
 456     ind = _pp_bgroup_tyname(pp, me)
 457     if cyclep: pp.text('...')
 458     else: pp.text('%#x' % me.p)
 459     pp.end_group(ind, ')')
 460 _augment(BinField, _tmp)
 461
 462 class _tmp:
 463   def __hash__(me): return 0x23e4701c ^ hash(me.p)
 464 _augment(BinPolyField, _tmp)
 465
 466 class _tmp:
 467   def __hash__(me):
 468     h = 0x9a7d6240
 469     h ^=   hash(me.p)
 470     h ^= 2*hash(me.beta) & 0xffffffff
 471     return h
 472 _augment(BinNormField, _tmp)
 473
 474 class _tmp:
 475   def __str__(me): return str(me.value)
 476   def __repr__(me): return '%s(%s)' % (repr(me.field), repr(me.value))
 477   _repr_pretty_ = _pp_str
 478 _augment(FE, _tmp)
 479
 480 ###--------------------------------------------------------------------------
 481 ### Elliptic curves.
 482
 483 class _tmp:
 484   def __repr__(me):
 485     return '%s(%r, %s, %s)' % (_clsname(me), me.field, me.a, me.b)
 486   def _repr_pretty_(me, pp, cyclep):
 487     ind = _pp_bgroup_tyname(pp, me)
 488     if cyclep:
 489       pp.text('...')
 490     else:
 491       pp.pretty(me.field); pp.text(','); pp.breakable()
 492       pp.pretty(me.a); pp.text(','); pp.breakable()
 493       pp.pretty(me.b)
 494     pp.end_group(ind, ')')
 495   def frombuf(me, s):
 496     return ecpt.frombuf(me, s)
 497   def fromraw(me, s):
 498     return ecpt.fromraw(me, s)
 499   def pt(me, *args):
 500     return me(*args)
 501 _augment(ECCurve, _tmp)
 502
 503 class _tmp:
 504   def __hash__(me):
 505     h = 0x6751d341
 506     h ^=   hash(me.field)
 507     h ^= 2*hash(me.a) ^ 0xffffffff
 508     h ^= 5*hash(me.b) ^ 0xffffffff
 509     return h
 510 _augment(ECPrimeCurve, _tmp)
 511
 512 class _tmp:
 513   def __hash__(me):
 514     h = 0x2ac203c5
 515     h ^=   hash(me.field)
 516     h ^= 2*hash(me.a) ^ 0xffffffff
 517     h ^= 5*hash(me.b) ^ 0xffffffff
 518     return h
 519 _augment(ECBinCurve, _tmp)
 520
 521 class _tmp:
 522   def __repr__(me):
 523     if not me: return '%s()' % _clsname(me)
 524     return '%s(%s, %s)' % (_clsname(me), me.ix, me.iy)
 525   def __str__(me):
 526     if not me: return 'inf'
 527     return '(%s, %s)' % (me.ix, me.iy)
 528   def _repr_pretty_(me, pp, cyclep):
 529     if cyclep:
 530       pp.text('...')
 531     elif not me:
 532       pp.text('inf')
 533     else:
 534       ind = _pp_bgroup(pp, '(')
 535       pp.pretty(me.ix); pp.text(','); pp.breakable()
 536       pp.pretty(me.iy)
 537       pp.end_group(ind, ')')
 538 _augment(ECPt, _tmp)
 539
 540 class _tmp:
 541   def __repr__(me):
 542     return '%s(curve = %r, G = %r, r = %s, h = %s)' % \
 543            (_clsname(me), me.curve, me.G, me.r, me.h)
 544   def _repr_pretty_(me, pp, cyclep):
 545     ind = _pp_bgroup_tyname(pp, me)
 546     if cyclep:
 547       pp.text('...')
 548     else:
 549       _pp_kv(pp, 'curve', me.curve); pp.text(','); pp.breakable()
 550       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 551       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 552       _pp_kv(pp, 'h', me.h)
 553     pp.end_group(ind, ')')
 554   def __hash__(me):
 555     h = 0x9bedb8de
 556     h ^=   hash(me.curve)
 557     h ^= 2*hash(me.G) & 0xffffffff
 558     return h
 559   def group(me):
 560     return ECGroup(me)
 561 _augment(ECInfo, _tmp)
 562
 563 class _tmp:
 564   def __repr__(me):
 565     if not me: return '%r()' % (me.curve)
 566     return '%r(%s, %s)' % (me.curve, me.x, me.y)
 567   def __str__(me):
 568     if not me: return 'inf'
 569     return '(%s, %s)' % (me.x, me.y)
 570   def _repr_pretty_(me, pp, cyclep):
 571     if cyclep:
 572       pp.text('...')
 573     elif not me:
 574       pp.text('inf')
 575     else:
 576       ind = _pp_bgroup(pp, '(')
 577       pp.pretty(me.x); pp.text(','); pp.breakable()
 578       pp.pretty(me.y)
 579       pp.end_group(ind, ')')
 580 _augment(ECPtCurve, _tmp)
 581
 582 ###--------------------------------------------------------------------------
 583 ### Key sizes.
 584
 585 class _tmp:
 586   def __repr__(me): return '%s(%d)' % (_clsname(me), me.default)
 587   def check(me, sz): return True
 588   def best(me, sz): return sz
 589 _augment(KeySZAny, _tmp)
 590
 591 class _tmp:
 592   def __repr__(me):
 593     return '%s(%d, %d, %d, %d)' % \
 594            (_clsname(me), me.default, me.min, me.max, me.mod)
 595   def _repr_pretty_(me, pp, cyclep):
 596     ind = _pp_bgroup_tyname(pp, me)
 597     if cyclep:
 598       pp.text('...')
 599     else:
 600       pp.pretty(me.default); pp.text(','); pp.breakable()
 601       pp.pretty(me.min); pp.text(','); pp.breakable()
 602       pp.pretty(me.max); pp.text(','); pp.breakable()
 603       pp.pretty(me.mod)
 604     pp.end_group(ind, ')')
 605   def check(me, sz): return me.min <= sz <= me.max and sz % me.mod == 0
 606   def best(me, sz):
 607     if sz < me.min: raise ValueError, 'key too small'
 608     elif sz > me.max: return me.max
 609     else: return sz - (sz % me.mod)
 610 _augment(KeySZRange, _tmp)
 611
 612 class _tmp:
 613   def __repr__(me): return '%s(%d, %s)' % (_clsname(me), me.default, me.set)
 614   def _repr_pretty_(me, pp, cyclep):
 615     ind = _pp_bgroup_tyname(pp, me)
 616     if cyclep:
 617       pp.text('...')
 618     else:
 619       pp.pretty(me.default); pp.text(','); pp.breakable()
 620       ind1 = _pp_bgroup(pp, '{')
 621       _pp_commas(pp, pp.pretty, me.set)
 622       pp.end_group(ind1, '}')
 623     pp.end_group(ind, ')')
 624   def check(me, sz): return sz in me.set
 625   def best(me, sz):
 626     found = -1
 627     for i in me.set:
 628       if found < i <= sz: found = i
 629     if found < 0: raise ValueError, 'key too small'
 630     return found
 631 _augment(KeySZSet, _tmp)
 632
 633 ###--------------------------------------------------------------------------
 634 ### Key data objects.
 635
 636 class _tmp:
 637   def __repr__(me): return '%s(%r)' % (_clsname(me), me.name)
 638 _augment(KeyFile, _tmp)
 639
 640 class _tmp:
 641   def __repr__(me): return '%s(%r)' % (_clsname(me), me.fulltag)
 642 _augment(Key, _tmp)
 643
 644 class _tmp:
 645   def __repr__(me):
 646     return '%s({%s})' % (_clsname(me),
 647                          ', '.join(['%r: %r' % kv for kv in me.iteritems()]))
 648   def _repr_pretty_(me, pp, cyclep):
 649     ind = _pp_bgroup_tyname(pp, me)
 650     if cyclep: pp.text('...')
 651     else: _pp_dict(pp, me.iteritems())
 652     pp.end_group(ind, ')')
 653 _augment(KeyAttributes, _tmp)
 654
 655 class _tmp:
 656   def __repr__(me):
 657     return '%s(%s, %r)' % (_clsname(me),
 658                            _repr_secret(me._guts(),
 659                                         not (me.flags & KF_NONSECRET)),
 660                            me.writeflags(me.flags))
 661   def _repr_pretty_(me, pp, cyclep):
 662     ind = _pp_bgroup_tyname(pp, me)
 663     if cyclep:
 664       pp.text('...')
 665     else:
 666       _pp_secret(pp, me._guts(), not (me.flags & KF_NONSECRET))
 667       pp.text(','); pp.breakable()
 668       pp.pretty(me.writeflags(me.flags))
 669     pp.end_group(ind, ')')
 670 _augment(KeyData, _tmp)
 671
 672 class _tmp:
 673   def _guts(me): return me.bin
 674 _augment(KeyDataBinary, _tmp)
 675
 676 class _tmp:
 677   def _guts(me): return me.ct
 678 _augment(KeyDataEncrypted, _tmp)
 679
 680 class _tmp:
 681   def _guts(me): return me.mp
 682 _augment(KeyDataMP, _tmp)
 683
 684 class _tmp:
 685   def _guts(me): return me.str
 686 _augment(KeyDataString, _tmp)
 687
 688 class _tmp:
 689   def _guts(me): return me.ecpt
 690 _augment(KeyDataECPt, _tmp)
 691
 692 class _tmp:
 693   def __repr__(me):
 694     return '%s({%s})' % (_clsname(me),
 695                          ', '.join(['%r: %r' % kv for kv in me.iteritems()]))
 696   def _repr_pretty_(me, pp, cyclep):
 697     ind = _pp_bgroup_tyname(pp, me, '({ ')
 698     if cyclep: pp.text('...')
 699     else: _pp_dict(pp, me.iteritems())
 700     pp.end_group(ind, ' })')
 701 _augment(KeyDataStructured, _tmp)
 702
 703 ###--------------------------------------------------------------------------
 704 ### Abstract groups.
 705
 706 class _tmp:
 707   def __repr__(me):
 708     return '%s(p = %s, r = %s, g = %s)' % (_clsname(me), me.p, me.r, me.g)
 709   def _repr_pretty_(me, pp, cyclep):
 710     ind = _pp_bgroup_tyname(pp, me)
 711     if cyclep:
 712       pp.text('...')
 713     else:
 714       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 715       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 716       _pp_kv(pp, 'g', me.g)
 717     pp.end_group(ind, ')')
 718 _augment(FGInfo, _tmp)
 719
 720 class _tmp:
 721   def group(me): return PrimeGroup(me)
 722 _augment(DHInfo, _tmp)
 723
 724 class _tmp:
 725   def group(me): return BinGroup(me)
 726 _augment(BinDHInfo, _tmp)
 727
 728 class _tmp:
 729   def __repr__(me):
 730     return '%s(%r)' % (_clsname(me), me.info)
 731   def _repr_pretty_(me, pp, cyclep):
 732     ind = _pp_bgroup_tyname(pp, me)
 733     if cyclep: pp.text('...')
 734     else: pp.pretty(me.info)
 735     pp.end_group(ind, ')')
 736 _augment(Group, _tmp)
 737
 738 class _tmp:
 739   def __hash__(me):
 740     info = me.info
 741     h = 0xbce3cfe6
 742     h ^=   hash(info.p)
 743     h ^= 2*hash(info.r) & 0xffffffff
 744     h ^= 5*hash(info.g) & 0xffffffff
 745     return h
 746   def _get_geval(me, x): return MP(x)
 747 _augment(PrimeGroup, _tmp)
 748
 749 class _tmp:
 750   def __hash__(me):
 751     info = me.info
 752     h = 0x80695949
 753     h ^=   hash(info.p)
 754     h ^= 2*hash(info.r) & 0xffffffff
 755     h ^= 5*hash(info.g) & 0xffffffff
 756     return h
 757   def _get_geval(me, x): return GF(x)
 758 _augment(BinGroup, _tmp)
 759
 760 class _tmp:
 761   def __hash__(me): return 0x0ec23dab ^ hash(me.info)
 762   def _get_geval(me, x): return x.toec()
 763 _augment(ECGroup, _tmp)
 764
 765 class _tmp:
 766   def __repr__(me):
 767     return '%r(%r)' % (me.group, str(me))
 768   def _repr_pretty_(me, pp, cyclep):
 769     pp.pretty(type(me)._get_geval(me))
 770 _augment(GE, _tmp)
 771
 772 ###--------------------------------------------------------------------------
 773 ### RSA encoding techniques.
 774
 775 class PKCS1Crypt (object):
 776   def __init__(me, ep = '', rng = rand):
 777     me.ep = ep
 778     me.rng = rng
 779   def encode(me, msg, nbits):
 780     return _base._p1crypt_encode(msg, nbits, me.ep, me.rng)
 781   def decode(me, ct, nbits):
 782     return _base._p1crypt_decode(ct, nbits, me.ep, me.rng)
 783
 784 class PKCS1Sig (object):
 785   def __init__(me, ep = '', rng = rand):
 786     me.ep = ep
 787     me.rng = rng
 788   def encode(me, msg, nbits):
 789     return _base._p1sig_encode(msg, nbits, me.ep, me.rng)
 790   def decode(me, msg, sig, nbits):
 791     return _base._p1sig_decode(msg, sig, nbits, me.ep, me.rng)
 792
 793 class OAEP (object):
 794   def __init__(me, mgf = sha_mgf, hash = sha, ep = '', rng = rand):
 795     me.mgf = mgf
 796     me.hash = hash
 797     me.ep = ep
 798     me.rng = rng
 799   def encode(me, msg, nbits):
 800     return _base._oaep_encode(msg, nbits, me.mgf, me.hash, me.ep, me.rng)
 801   def decode(me, ct, nbits):
 802     return _base._oaep_decode(ct, nbits, me.mgf, me.hash, me.ep, me.rng)
 803
 804 class PSS (object):
 805   def __init__(me, mgf = sha_mgf, hash = sha, saltsz = None, rng = rand):
 806     me.mgf = mgf
 807     me.hash = hash
 808     if saltsz is None:
 809       saltsz = hash.hashsz
 810     me.saltsz = saltsz
 811     me.rng = rng
 812   def encode(me, msg, nbits):
 813     return _base._pss_encode(msg, nbits, me.mgf, me.hash, me.saltsz, me.rng)
 814   def decode(me, msg, sig, nbits):
 815     return _base._pss_decode(msg, sig, nbits,
 816                              me.mgf, me.hash, me.saltsz, me.rng)
 817
 818 class _tmp:
 819   def encrypt(me, msg, enc):
 820     return me.pubop(enc.encode(msg, me.n.nbits))
 821   def verify(me, msg, sig, enc):
 822     if msg is None: return enc.decode(msg, me.pubop(sig), me.n.nbits)
 823     try:
 824       x = enc.decode(msg, me.pubop(sig), me.n.nbits)
 825       return x is None or x == msg
 826     except ValueError:
 827       return False
 828   def __repr__(me):
 829     return '%s(n = %r, e = %r)' % (_clsname(me), me.n, me.e)
 830   def _repr_pretty_(me, pp, cyclep):
 831     ind = _pp_bgroup_tyname(pp, me)
 832     if cyclep:
 833       pp.text('...')
 834     else:
 835       _pp_kv(pp, 'n', me.n); pp.text(','); pp.breakable()
 836       _pp_kv(pp, 'e', me.e)
 837     pp.end_group(ind, ')')
 838 _augment(RSAPub, _tmp)
 839
 840 class _tmp:
 841   def decrypt(me, ct, enc): return enc.decode(me.privop(ct), me.n.nbits)
 842   def sign(me, msg, enc): return me.privop(enc.encode(msg, me.n.nbits))
 843   def __repr__(me):
 844     return '%s(n = %r, e = %r, d = %s, ' \
 845       'p = %s, q = %s, dp = %s, dq = %s, q_inv = %s)' % \
 846       (_clsname(me), me.n, me.e,
 847        _repr_secret(me.d), _repr_secret(me.p), _repr_secret(me.q),
 848        _repr_secret(me.dp), _repr_secret(me.dq), _repr_secret(me.q_inv))
 849   def _repr_pretty_(me, pp, cyclep):
 850     ind = _pp_bgroup_tyname(pp, me)
 851     if cyclep:
 852       pp.text('...')
 853     else:
 854       _pp_kv(pp, 'n', me.n); pp.text(','); pp.breakable()
 855       _pp_kv(pp, 'e', me.e); pp.text(','); pp.breakable()
 856       _pp_kv(pp, 'd', me.d, secretp = True); pp.text(','); pp.breakable()
 857       _pp_kv(pp, 'p', me.p, secretp = True); pp.text(','); pp.breakable()
 858       _pp_kv(pp, 'q', me.q, secretp = True); pp.text(','); pp.breakable()
 859       _pp_kv(pp, 'dp', me.dp, secretp = True); pp.text(','); pp.breakable()
 860       _pp_kv(pp, 'dq', me.dq, secretp = True); pp.text(','); pp.breakable()
 861       _pp_kv(pp, 'q_inv', me.q_inv, secretp = True)
 862     pp.end_group(ind, ')')
 863 _augment(RSAPriv, _tmp)
 864
 865 ###--------------------------------------------------------------------------
 866 ### DSA and related schemes.
 867
 868 class _tmp:
 869   def __repr__(me): return '%s(G = %r, p = %r)' % (_clsname(me), me.G, me.p)
 870   def _repr_pretty_(me, pp, cyclep):
 871     ind = _pp_bgroup_tyname(pp, me)
 872     if cyclep:
 873       pp.text('...')
 874     else:
 875       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 876       _pp_kv(pp, 'p', me.p)
 877     pp.end_group(ind, ')')
 878 _augment(DSAPub, _tmp)
 879 _augment(KCDSAPub, _tmp)
 880
 881 class _tmp:
 882   def __repr__(me): return '%s(G = %r, u = %s, p = %r)' % \
 883       (_clsname(me), me.G, _repr_secret(me.u), me.p)
 884   def _repr_pretty_(me, pp, cyclep):
 885     ind = _pp_bgroup_tyname(pp, me)
 886     if cyclep:
 887       pp.text('...')
 888     else:
 889       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 890       _pp_kv(pp, 'u', me.u, True); pp.text(','); pp.breakable()
 891       _pp_kv(pp, 'p', me.p)
 892     pp.end_group(ind, ')')
 893 _augment(DSAPriv, _tmp)
 894 _augment(KCDSAPriv, _tmp)
 895
 896 ###--------------------------------------------------------------------------
 897 ### Bernstein's elliptic curve crypto and related schemes.
 898
 899 X25519_BASE = MP(9).storel(32)
 900 X448_BASE = MP(5).storel(56)
 901
 902 Z128 = ByteString.zero(16)
 903
 904 class _BasePub (object):
 905   def __init__(me, pub, *args, **kw):
 906     if not me._PUBSZ.check(len(pub)): raise ValueError, 'bad public key'
 907     super(_BasePub, me).__init__(*args, **kw)
 908     me.pub = pub
 909   def __repr__(me): return '%s(pub = %r)' % (_clsname(me), me.pub)
 910   def _pp(me, pp): _pp_kv(pp, 'pub', me.pub)
 911   def _repr_pretty_(me, pp, cyclep):
 912     ind = _pp_bgroup_tyname(pp, me)
 913     if cyclep: pp.text('...')
 914     else: me._pp(pp)
 915     pp.end_group(ind, ')')
 916
 917 class _BasePriv (object):
 918   def __init__(me, priv, pub = None, *args, **kw):
 919     if not me._KEYSZ.check(len(priv)): raise ValueError, 'bad private key'
 920     if pub is None: pub = me._pubkey(priv)
 921     super(_BasePriv, me).__init__(pub = pub, *args, **kw)
 922     me.priv = priv
 923   @classmethod
 924   def generate(cls, rng = rand):
 925     return cls(rng.block(cls._KEYSZ.default))
 926   def __repr__(me):
 927     return '%s(priv = %d, pub = %r)' % \
 928         (_clsname(me), _repr_secret(me.priv), me.pub)
 929   def _pp(me, pp):
 930     _pp_kv(pp, 'priv', me.priv, secretp = True); pp.text(','); pp.breakable()
 931     super(_BasePriv, me)._pp(pp)
 932
 933 class _XDHPub (_BasePub):  pass
 934
 935 class _XDHPriv (_BasePriv):
 936   def _pubkey(me, priv): return me._op(priv, me._BASE)
 937   def agree(me, you): return me._op(me.priv, you.pub)
 938   def boxkey(me, recip): return me._hashkey(me.agree(recip))
 939   def box(me, recip, n, m): return secret_box(me.boxkey(recip), n, m)
 940   def unbox(me, recip, n, c): return secret_unbox(me.boxkey(recip), n, c)
 941
 942 class X25519Pub (_XDHPub):
 943   _PUBSZ = KeySZSet(X25519_PUBSZ)
 944   _BASE = X25519_BASE
 945
 946 class X25519Priv (_XDHPriv, X25519Pub):
 947   _KEYSZ = KeySZSet(X25519_KEYSZ)
 948   def _op(me, k, X): return x25519(k, X)
 949   def _hashkey(me, z): return hsalsa20_prf(z, Z128)
 950
 951 class X448Pub (_XDHPub):
 952   _PUBSZ = KeySZSet(X448_PUBSZ)
 953   _BASE = X448_BASE
 954
 955 class X448Priv (_XDHPriv, X448Pub):
 956   _KEYSZ = KeySZSet(X448_KEYSZ)
 957   def _op(me, k, X): return x448(k, X)
 958   def _hashkey(me, z): return Shake256().hash(z).done(salsa20.keysz.default)
 959
 960 class _EdDSAPub (_BasePub):
 961   def beginhash(me): return me._HASH()
 962   def endhash(me, h): return h.done()
 963
 964 class _EdDSAPriv (_BasePriv, _EdDSAPub):
 965   pass
 966
 967 class Ed25519Pub (_EdDSAPub):
 968   _PUBSZ = KeySZSet(ED25519_PUBSZ)
 969   _HASH = sha512
 970   def verify(me, msg, sig, **kw):
 971     return ed25519_verify(me.pub, msg, sig, **kw)
 972
 973 class Ed25519Priv (_EdDSAPriv, Ed25519Pub):
 974   _KEYSZ = KeySZAny(ED25519_KEYSZ)
 975   def _pubkey(me, priv): return ed25519_pubkey(priv)
 976   def sign(me, msg, **kw):
 977     return ed25519_sign(me.priv, msg, pub = me.pub, **kw)
 978
 979 class Ed448Pub (_EdDSAPub):
 980   _PUBSZ = KeySZSet(ED448_PUBSZ)
 981   _HASH = shake256
 982   def verify(me, msg, sig, **kw):
 983     return ed448_verify(me.pub, msg, sig, **kw)
 984
 985 class Ed448Priv (_EdDSAPriv, Ed448Pub):
 986   _KEYSZ = KeySZAny(ED448_KEYSZ)
 987   def _pubkey(me, priv): return ed448_pubkey(priv)
 988   def sign(me, msg, **kw):
 989     return ed448_sign(me.priv, msg, pub = me.pub, **kw)
 990
 991 ###--------------------------------------------------------------------------
 992 ### Built-in named curves and prime groups.
 993
 994 class _groupmap (object):
 995   def __init__(me, map, nth):
 996     me.map = map
 997     me.nth = nth
 998     me._n = max(map.values()) + 1
 999     me.i = me._n*[None]
1000   def __repr__(me):
1001     return '{%s}' % ', '.join(['%r: %r' % kv for kv in me.iteritems()])
1002   def _repr_pretty_(me, pp, cyclep):
1003     ind = _pp_bgroup(pp, '{ ')
1004     if cyclep: pp.text('...')
1005     else: _pp_dict(pp, me.iteritems())
1006     pp.end_group(ind, ' }')
1007   def __len__(me):
1008     return me._n
1009   def __contains__(me, k):
1010     return k in me.map
1011   def __getitem__(me, k):
1012     i = me.map[k]
1013     if me.i[i] is None:
1014       me.i[i] = me.nth(i)
1015     return me.i[i]
1016   def __setitem__(me, k, v):
1017     raise TypeError, "immutable object"
1018   def __iter__(me):
1019     return iter(me.map)
1020   def iterkeys(me):
1021     return iter(me.map)
1022   def itervalues(me):
1023     for k in me:
1024       yield me[k]
1025   def iteritems(me):
1026     for k in me:
1027       yield k, me[k]
1028   def keys(me):
1029     return [k for k in me]
1030   def values(me):
1031     return [me[k] for k in me]
1032   def items(me):
1033     return [(k, me[k]) for k in me]
1034 eccurves = _groupmap(_base._eccurves, ECInfo._curven)
1035 primegroups = _groupmap(_base._pgroups, DHInfo._groupn)
1036 bingroups = _groupmap(_base._bingroups, BinDHInfo._groupn)
1037
1038 ###--------------------------------------------------------------------------
1039 ### Prime number generation.
1040
1041 class PrimeGenEventHandler (object):
1042   def pg_begin(me, ev):
1043     return me.pg_try(ev)
1044   def pg_done(me, ev):
1045     return PGEN_DONE
1046   def pg_abort(me, ev):
1047     return PGEN_TRY
1048   def pg_fail(me, ev):
1049     return PGEN_TRY
1050   def pg_pass(me, ev):
1051     return PGEN_TRY
1052
1053 class SophieGermainStepJump (object):
1054   def pg_begin(me, ev):
1055     me.lf = PrimeFilter(ev.x)
1056     me.hf = me.lf.muladd(2, 1)
1057     return me.cont(ev)
1058   def pg_try(me, ev):
1059     me.step()
1060     return me.cont(ev)
1061   def cont(me, ev):
1062     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
1063       me.step()
1064     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
1065       return PGEN_ABORT
1066     ev.x = me.lf.x
1067     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
1068       return PGEN_DONE
1069     return PGEN_TRY
1070   def pg_done(me, ev):
1071     del me.lf
1072     del me.hf
1073
1074 class SophieGermainStepper (SophieGermainStepJump):
1075   def __init__(me, step):
1076     me.lstep = step;
1077     me.hstep = 2 * step
1078   def step(me):
1079     me.lf.step(me.lstep)
1080     me.hf.step(me.hstep)
1081
1082 class SophieGermainJumper (SophieGermainStepJump):
1083   def __init__(me, jump):
1084     me.ljump = PrimeFilter(jump);
1085     me.hjump = me.ljump.muladd(2, 0)
1086   def step(me):
1087     me.lf.jump(me.ljump)
1088     me.hf.jump(me.hjump)
1089   def pg_done(me, ev):
1090     del me.ljump
1091     del me.hjump
1092     SophieGermainStepJump.pg_done(me, ev)
1093
1094 class SophieGermainTester (object):
1095   def __init__(me):
1096     pass
1097   def pg_begin(me, ev):
1098     me.lr = RabinMiller(ev.x)
1099     me.hr = RabinMiller(2 * ev.x + 1)
1100   def pg_try(me, ev):
1101     lst = me.lr.test(ev.rng.range(me.lr.x))
1102     if lst != PGEN_PASS and lst != PGEN_DONE:
1103       return lst
1104     rst = me.hr.test(ev.rng.range(me.hr.x))
1105     if rst != PGEN_PASS and rst != PGEN_DONE:
1106       return rst
1107     if lst == PGEN_DONE and rst == PGEN_DONE:
1108       return PGEN_DONE
1109     return PGEN_PASS
1110   def pg_done(me, ev):
1111     del me.lr
1112     del me.hr
1113
1114 class PrimitiveStepper (PrimeGenEventHandler):
1115   def __init__(me):
1116     pass
1117   def pg_try(me, ev):
1118     ev.x = me.i.next()
1119     return PGEN_TRY
1120   def pg_begin(me, ev):
1121     me.i = iter(smallprimes)
1122     return me.pg_try(ev)
1123
1124 class PrimitiveTester (PrimeGenEventHandler):
1125   def __init__(me, mod, hh = [], exp = None):
1126     me.mod = MPMont(mod)
1127     me.exp = exp
1128     me.hh = hh
1129   def pg_try(me, ev):
1130     x = ev.x
1131     if me.exp is not None:
1132       x = me.mod.exp(x, me.exp)
1133       if x == 1: return PGEN_FAIL
1134     for h in me.hh:
1135       if me.mod.exp(x, h) == 1: return PGEN_FAIL
1136     ev.x = x
1137     return PGEN_DONE
1138
1139 class SimulStepper (PrimeGenEventHandler):
1140   def __init__(me, mul = 2, add = 1, step = 2):
1141     me.step = step
1142     me.mul = mul
1143     me.add = add
1144   def _stepfn(me, step):
1145     if step <= 0:
1146       raise ValueError, 'step must be positive'
1147     if step <= MPW_MAX:
1148       return lambda f: f.step(step)
1149     j = PrimeFilter(step)
1150     return lambda f: f.jump(j)
1151   def pg_begin(me, ev):
1152     x = ev.x
1153     me.lf = PrimeFilter(x)
1154     me.hf = PrimeFilter(x * me.mul + me.add)
1155     me.lstep = me._stepfn(me.step)
1156     me.hstep = me._stepfn(me.step * me.mul)
1157     SimulStepper._cont(me, ev)
1158   def pg_try(me, ev):
1159     me._step()
1160     me._cont(ev)
1161   def _step(me):
1162     me.lstep(me.lf)
1163     me.hstep(me.hf)
1164   def _cont(me, ev):
1165     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
1166       me._step()
1167     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
1168       return PGEN_ABORT
1169     ev.x = me.lf.x
1170     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
1171       return PGEN_DONE
1172     return PGEN_TRY
1173   def pg_done(me, ev):
1174     del me.lf
1175     del me.hf
1176     del me.lstep
1177     del me.hstep
1178
1179 class SimulTester (PrimeGenEventHandler):
1180   def __init__(me, mul = 2, add = 1):
1181     me.mul = mul
1182     me.add = add
1183   def pg_begin(me, ev):
1184     x = ev.x
1185     me.lr = RabinMiller(x)
1186     me.hr = RabinMiller(x * me.mul + me.add)
1187   def pg_try(me, ev):
1188     lst = me.lr.test(ev.rng.range(me.lr.x))
1189     if lst != PGEN_PASS and lst != PGEN_DONE:
1190       return lst
1191     rst = me.hr.test(ev.rng.range(me.hr.x))
1192     if rst != PGEN_PASS and rst != PGEN_DONE:
1193       return rst
1194     if lst == PGEN_DONE and rst == PGEN_DONE:
1195       return PGEN_DONE
1196     return PGEN_PASS
1197   def pg_done(me, ev):
1198     del me.lr
1199     del me.hr
1200
1201 def sgprime(start, step = 2, name = 'p', event = pgen_nullev, nsteps = 0):
1202   start = MP(start)
1203   return pgen(start, name, SimulStepper(step = step), SimulTester(), event,
1204               nsteps, RabinMiller.iters(start.nbits))
1205
1206 def findprimitive(mod, hh = [], exp = None, name = 'g', event = pgen_nullev):
1207   return pgen(0, name, PrimitiveStepper(), PrimitiveTester(mod, hh, exp),
1208               event, 0, 1)
1209
1210 def kcdsaprime(pbits, qbits, rng = rand,
1211                event = pgen_nullev, name = 'p', nsteps = 0):
1212   hbits = pbits - qbits
1213   h = pgen(rng.mp(hbits, 1), name + ' [h]',
1214            PrimeGenStepper(2), PrimeGenTester(),
1215            event, nsteps, RabinMiller.iters(hbits))
1216   q = pgen(rng.mp(qbits, 1), name, SimulStepper(2 * h, 1, 2),
1217            SimulTester(2 * h, 1), event, nsteps, RabinMiller.iters(qbits))
1218   p = 2 * q * h + 1
1219   return p, q, h
1220
1221 #----- That's all, folks ----------------------------------------------------