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