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 import DLFCN as _dlfcn
  31 import os as _os
  32 from struct import pack as _pack
  33 import sys as _sys
  34 import types as _types
  35
  36 ###--------------------------------------------------------------------------
  37 ### Import the main C extension module.
  38
  39 try:
  40   _dlflags = _odlflags = _sys.getdlopenflags()
  41 except AttributeError:
  42   _dlflags = _odlflags = -1
  43
  44 ## Set the `deep binding' flag.  Python has its own different MD5
  45 ## implementation, and some distributions export `md5_init' and friends so
  46 ## they override our versions, which doesn't end well.  Figure out how to
  47 ## turn this flag on so we don't have the problem.
  48 if _dlflags >= 0:
  49   try: _dlflags |= _dlfcn.RTLD_DEEPBIND
  50   except AttributeError:
  51     try: _dlflags |= _os.RTLD_DEEPBIND
  52     except AttributeError:
  53       if _os.uname()[0] == 'Linux': _dlflags |= 8 # magic knowledge
  54       else: pass # can't do this.
  55   _sys.setdlopenflags(_dlflags)
  56
  57 import _base
  58
  59 if _odlflags >= 0:
  60   _sys.setdlopenflags(_odlflags)
  61
  62 del _dlflags, _odlflags
  63
  64 ###--------------------------------------------------------------------------
  65 ### Basic stuff.
  66
  67 ## For the benefit of the default keyreporter, we need the program name.
  68 _base._ego(_sys.argv[0])
  69
  70 ## How to fix a name back into the right identifier.  Alas, the rules are not
  71 ## consistent.
  72 def _fixname(name):
  73
  74   ## Hyphens consistently become underscores.
  75   name = name.replace('-', '_')
  76
  77   ## But slashes might become underscores or just vanish.
  78   if name.startswith('salsa20'): name = name.translate(None, '/')
  79   else: name = name.replace('/', '_')
  80
  81   ## Done.
  82   return name
  83
  84 ## Initialize the module.  Drag in the static methods of the various
  85 ## classes; create names for the various known crypto algorithms.
  86 def _init():
  87   d = globals()
  88   b = _base.__dict__;
  89   for i in b:
  90     if i[0] != '_':
  91       d[i] = b[i];
  92   for i in ['ByteString',
  93             'MP', 'GF', 'Field',
  94             'ECPt', 'ECPtCurve', 'ECCurve', 'ECInfo',
  95             'DHInfo', 'BinDHInfo', 'RSAPriv', 'BBSPriv',
  96             'PrimeFilter', 'RabinMiller',
  97             'Group', 'GE',
  98             'KeySZ', 'KeyData']:
  99     c = d[i]
 100     pre = '_' + i + '_'
 101     plen = len(pre)
 102     for j in b:
 103       if j[:plen] == pre:
 104         setattr(c, j[plen:], classmethod(b[j]))
 105   for i in [gcciphers, gchashes, gcmacs, gcprps]:
 106     for c in i.itervalues():
 107       d[_fixname(c.name)] = c
 108   for c in gccrands.itervalues():
 109     d[_fixname(c.name + 'rand')] = c
 110 _init()
 111
 112 ## A handy function for our work: add the methods of a named class to an
 113 ## existing class.  This is how we write the Python-implemented parts of our
 114 ## mostly-C types.
 115 def _augment(c, cc):
 116   for i in cc.__dict__:
 117     a = cc.__dict__[i]
 118     if type(a) is _types.MethodType:
 119       a = a.im_func
 120     elif type(a) not in (_types.FunctionType, staticmethod, classmethod):
 121       continue
 122     setattr(c, i, a)
 123
 124 ## Parsing functions tend to return the object parsed and the remainder of
 125 ## the input.  This checks that the remainder is input and, if so, returns
 126 ## just the object.
 127 def _checkend(r):
 128   x, rest = r
 129   if rest != '':
 130     raise SyntaxError, 'junk at end of string'
 131   return x
 132
 133 ## Some pretty-printing utilities.
 134 PRINT_SECRETS = False
 135 def _clsname(me): return type(me).__name__
 136 def _repr_secret(thing, secretp = True):
 137   if not secretp or PRINT_SECRETS: return repr(thing)
 138   else: return '#<SECRET>'
 139 def _pp_str(me, pp, cyclep): pp.text(cyclep and '...' or str(me))
 140 def _pp_secret(pp, thing, secretp = True):
 141   if not secretp or PRINT_SECRETS: pp.pretty(thing)
 142   else: pp.text('#<SECRET>')
 143 def _pp_bgroup(pp, text):
 144   ind = len(text)
 145   pp.begin_group(ind, text)
 146   return ind
 147 def _pp_bgroup_tyname(pp, obj, open = '('):
 148   return _pp_bgroup(pp, _clsname(obj) + open)
 149 def _pp_kv(pp, k, v, secretp = False):
 150   ind = _pp_bgroup(pp, k + ' = ')
 151   _pp_secret(pp, v, secretp)
 152   pp.end_group(ind, '')
 153 def _pp_commas(pp, printfn, items):
 154   firstp = True
 155   for i in items:
 156     if firstp: firstp = False
 157     else: pp.text(','); pp.breakable()
 158     printfn(i)
 159 def _pp_dict(pp, items):
 160   def p((k, v)):
 161     pp.begin_group(0)
 162     pp.pretty(k)
 163     pp.text(':')
 164     pp.begin_group(2)
 165     pp.breakable()
 166     pp.pretty(v)
 167     pp.end_group(2)
 168     pp.end_group(0)
 169   _pp_commas(pp, p, items)
 170
 171 ###--------------------------------------------------------------------------
 172 ### Bytestrings.
 173
 174 class _tmp:
 175   def fromhex(x):
 176     return ByteString(_unhexify(x))
 177   fromhex = staticmethod(fromhex)
 178   def __hex__(me):
 179     return _hexify(me)
 180   def __repr__(me):
 181     return 'bytes(%r)' % hex(me)
 182 _augment(ByteString, _tmp)
 183 ByteString.__hash__ = str.__hash__
 184 bytes = ByteString.fromhex
 185
 186 ###--------------------------------------------------------------------------
 187 ### Hashing.
 188
 189 class _tmp:
 190   def check(me, h):
 191     hh = me.done()
 192     return ctstreq(h, hh)
 193 _augment(GHash, _tmp)
 194 _augment(Poly1305Hash, _tmp)
 195
 196 class _HashBase (object):
 197   ## The standard hash methods.  Assume that `hash' is defined and returns
 198   ## the receiver.
 199   def hashu8(me, n): return me.hash(_pack('B', n))
 200   def hashu16l(me, n): return me.hash(_pack('<H', n))
 201   def hashu16b(me, n): return me.hash(_pack('>H', n))
 202   hashu16 = hashu16b
 203   def hashu32l(me, n): return me.hash(_pack('<L', n))
 204   def hashu32b(me, n): return me.hash(_pack('>L', n))
 205   hashu32 = hashu32b
 206   def hashu64l(me, n): return me.hash(_pack('<Q', n))
 207   def hashu64b(me, n): return me.hash(_pack('>Q', n))
 208   hashu64 = hashu64b
 209   def hashbuf8(me, s): return me.hashu8(len(s)).hash(s)
 210   def hashbuf16l(me, s): return me.hashu16l(len(s)).hash(s)
 211   def hashbuf16b(me, s): return me.hashu16b(len(s)).hash(s)
 212   hashbuf16 = hashbuf16b
 213   def hashbuf32l(me, s): return me.hashu32l(len(s)).hash(s)
 214   def hashbuf32b(me, s): return me.hashu32b(len(s)).hash(s)
 215   hashbuf32 = hashbuf32b
 216   def hashbuf64l(me, s): return me.hashu64l(len(s)).hash(s)
 217   def hashbuf64b(me, s): return me.hashu64b(len(s)).hash(s)
 218   hashbuf64 = hashbuf64b
 219   def hashstrz(me, s): return me.hash(s).hashu8(0)
 220
 221 class _ShakeBase (_HashBase):
 222
 223   ## Python gets really confused if I try to augment `__new__' on native
 224   ## classes, so wrap and delegate.  Sorry.
 225   def __init__(me, perso = '', *args, **kw):
 226     super(_ShakeBase, me).__init__(*args, **kw)
 227     me._h = me._SHAKE(perso = perso, func = me._FUNC)
 228
 229   ## Delegate methods...
 230   def copy(me): new = me.__class__(); new._copy(me)
 231   def _copy(me, other): me._h = other._h
 232   def hash(me, m): me._h.hash(m); return me
 233   def xof(me): me._h.xof(); return me
 234   def get(me, n): return me._h.get(n)
 235   def mask(me, m): return me._h.mask(m)
 236   def done(me, n): return me._h.done(n)
 237   def check(me, h): return ctstreq(h, me.done(len(h)))
 238   @property
 239   def state(me): return me._h.state
 240   @property
 241   def buffered(me): return me._h.buffered
 242   @property
 243   def rate(me): return me._h.rate
 244
 245 class _tmp:
 246   def check(me, h):
 247     return ctstreq(h, me.done(len(h)))
 248   def leftenc(me, n):
 249     nn = MP(n).storeb()
 250     return me.hashu8(len(nn)).hash(nn)
 251   def rightenc(me, n):
 252     nn = MP(n).storeb()
 253     return me.hash(nn).hashu8(len(nn))
 254   def stringenc(me, str):
 255     return me.leftenc(8*len(str)).hash(str)
 256   def bytepad_before(me):
 257     return me.leftenc(me.rate)
 258   def bytepad_after(me):
 259     if me.buffered: me.hash(me._Z[:me.rate - me.buffered])
 260     return me
 261   @_ctxmgr
 262   def bytepad(me):
 263     me.bytepad_before()
 264     yield me
 265     me.bytepad_after()
 266 _augment(Shake, _tmp)
 267 _augment(_ShakeBase, _tmp)
 268 Shake._Z = _ShakeBase._Z = ByteString.zero(200)
 269
 270 class KMAC (_ShakeBase):
 271   _FUNC = 'KMAC'
 272   def __init__(me, k, *arg, **kw):
 273     super(KMAC, me).__init__(*arg, **kw)
 274     with me.bytepad(): me.stringenc(k)
 275   def done(me, n = -1):
 276     if n < 0: n = me._TAGSZ
 277     me.rightenc(8*n)
 278     return super(KMAC, me).done(n)
 279   def xof(me):
 280     me.rightenc(0)
 281     return super(KMAC, me).xof()
 282
 283 class KMAC128 (KMAC): _SHAKE = Shake128; _TAGSZ = 16
 284 class KMAC256 (KMAC): _SHAKE = Shake256; _TAGSZ = 32
 285
 286 ###--------------------------------------------------------------------------
 287 ### NaCl `secretbox'.
 288
 289 def secret_box(k, n, m):
 290   E = xsalsa20(k).setiv(n)
 291   r = E.enczero(poly1305.keysz.default)
 292   s = E.enczero(poly1305.masksz)
 293   y = E.encrypt(m)
 294   t = poly1305(r)(s).hash(y).done()
 295   return t + y
 296
 297 def secret_unbox(k, n, c):
 298   E = xsalsa20(k).setiv(n)
 299   r = E.enczero(poly1305.keysz.default)
 300   s = E.enczero(poly1305.masksz)
 301   y = c[poly1305.tagsz:]
 302   if not poly1305(r)(s).hash(y).check(c[0:poly1305.tagsz]):
 303     raise ValueError, 'decryption failed'
 304   return E.decrypt(c[poly1305.tagsz:])
 305
 306 ###--------------------------------------------------------------------------
 307 ### Multiprecision integers and binary polynomials.
 308
 309 def _split_rat(x):
 310   if isinstance(x, BaseRat): return x._n, x._d
 311   else: return x, 1
 312 class BaseRat (object):
 313   """Base class implementing fields of fractions over Euclidean domains."""
 314   def __new__(cls, a, b):
 315     a, b = cls.RING(a), cls.RING(b)
 316     q, r = divmod(a, b)
 317     if r == 0: return q
 318     g = b.gcd(r)
 319     me = super(BaseRat, cls).__new__(cls)
 320     me._n = a//g
 321     me._d = b//g
 322     return me
 323   @property
 324   def numer(me): return me._n
 325   @property
 326   def denom(me): return me._d
 327   def __str__(me): return '%s/%s' % (me._n, me._d)
 328   def __repr__(me): return '%s(%s, %s)' % (_clsname(me), me._n, me._d)
 329   _repr_pretty_ = _pp_str
 330
 331   def __add__(me, you):
 332     n, d = _split_rat(you)
 333     return type(me)(me._n*d + n*me._d, d*me._d)
 334   __radd__ = __add__
 335   def __sub__(me, you):
 336     n, d = _split_rat(you)
 337     return type(me)(me._n*d - n*me._d, d*me._d)
 338   def __rsub__(me, you):
 339     n, d = _split_rat(you)
 340     return type(me)(n*me._d - me._n*d, d*me._d)
 341   def __mul__(me, you):
 342     n, d = _split_rat(you)
 343     return type(me)(me._n*n, me._d*d)
 344   def __div__(me, you):
 345     n, d = _split_rat(you)
 346     return type(me)(me._n*d, me._d*n)
 347   def __rdiv__(me, you):
 348     n, d = _split_rat(you)
 349     return type(me)(me._d*n, me._n*d)
 350   def __cmp__(me, you):
 351     n, d = _split_rat(you)
 352     return type(me)(me._n*d, n*me._d)
 353   def __rcmp__(me, you):
 354     n, d = _split_rat(you)
 355     return cmp(n*me._d, me._n*d)
 356
 357 class IntRat (BaseRat):
 358   RING = MP
 359
 360 class GFRat (BaseRat):
 361   RING = GF
 362
 363 class _tmp:
 364   def negp(x): return x < 0
 365   def posp(x): return x > 0
 366   def zerop(x): return x == 0
 367   def oddp(x): return x.testbit(0)
 368   def evenp(x): return not x.testbit(0)
 369   def mont(x): return MPMont(x)
 370   def barrett(x): return MPBarrett(x)
 371   def reduce(x): return MPReduce(x)
 372   def __div__(me, you): return IntRat(me, you)
 373   def __rdiv__(me, you): return IntRat(you, me)
 374   _repr_pretty_ = _pp_str
 375 _augment(MP, _tmp)
 376
 377 class _tmp:
 378   def zerop(x): return x == 0
 379   def reduce(x): return GFReduce(x)
 380   def trace(x, y): return x.reduce().trace(y)
 381   def halftrace(x, y): return x.reduce().halftrace(y)
 382   def modsqrt(x, y): return x.reduce().sqrt(y)
 383   def quadsolve(x, y): return x.reduce().quadsolve(y)
 384   def __div__(me, you): return GFRat(me, you)
 385   def __rdiv__(me, you): return GFRat(you, me)
 386   _repr_pretty_ = _pp_str
 387 _augment(GF, _tmp)
 388
 389 class _tmp:
 390   def product(*arg):
 391     'product(ITERABLE) or product(I, ...) -> PRODUCT'
 392     return MPMul(*arg).done()
 393   product = staticmethod(product)
 394 _augment(MPMul, _tmp)
 395
 396 ###--------------------------------------------------------------------------
 397 ### Abstract fields.
 398
 399 class _tmp:
 400   def fromstring(str): return _checkend(Field.parse(str))
 401   fromstring = staticmethod(fromstring)
 402 _augment(Field, _tmp)
 403
 404 class _tmp:
 405   def __repr__(me): return '%s(%sL)' % (_clsname(me), me.p)
 406   def __hash__(me): return 0x114401de ^ hash(me.p)
 407   def _repr_pretty_(me, pp, cyclep):
 408     ind = _pp_bgroup_tyname(pp, me)
 409     if cyclep: pp.text('...')
 410     else: pp.pretty(me.p)
 411     pp.end_group(ind, ')')
 412   def ec(me, a, b): return ECPrimeProjCurve(me, a, b)
 413 _augment(PrimeField, _tmp)
 414
 415 class _tmp:
 416   def __repr__(me): return '%s(%#xL)' % (_clsname(me), me.p)
 417   def ec(me, a, b): return ECBinProjCurve(me, a, b)
 418   def _repr_pretty_(me, pp, cyclep):
 419     ind = _pp_bgroup_tyname(pp, me)
 420     if cyclep: pp.text('...')
 421     else: pp.text('%#x' % me.p)
 422     pp.end_group(ind, ')')
 423 _augment(BinField, _tmp)
 424
 425 class _tmp:
 426   def __hash__(me): return 0x23e4701c ^ hash(me.p)
 427 _augment(BinPolyField, _tmp)
 428
 429 class _tmp:
 430   def __hash__(me):
 431     h = 0x9a7d6240
 432     h ^=   hash(me.p)
 433     h ^= 2*hash(me.beta) & 0xffffffff
 434     return h
 435 _augment(BinNormField, _tmp)
 436
 437 class _tmp:
 438   def __str__(me): return str(me.value)
 439   def __repr__(me): return '%s(%s)' % (repr(me.field), repr(me.value))
 440   _repr_pretty_ = _pp_str
 441 _augment(FE, _tmp)
 442
 443 ###--------------------------------------------------------------------------
 444 ### Elliptic curves.
 445
 446 class _tmp:
 447   def __repr__(me):
 448     return '%s(%r, %s, %s)' % (_clsname(me), me.field, me.a, me.b)
 449   def _repr_pretty_(me, pp, cyclep):
 450     ind = _pp_bgroup_tyname(pp, me)
 451     if cyclep:
 452       pp.text('...')
 453     else:
 454       pp.pretty(me.field); pp.text(','); pp.breakable()
 455       pp.pretty(me.a); pp.text(','); pp.breakable()
 456       pp.pretty(me.b)
 457     pp.end_group(ind, ')')
 458   def frombuf(me, s):
 459     return ecpt.frombuf(me, s)
 460   def fromraw(me, s):
 461     return ecpt.fromraw(me, s)
 462   def pt(me, *args):
 463     return me(*args)
 464 _augment(ECCurve, _tmp)
 465
 466 class _tmp:
 467   def __hash__(me):
 468     h = 0x6751d341
 469     h ^=   hash(me.field)
 470     h ^= 2*hash(me.a) ^ 0xffffffff
 471     h ^= 5*hash(me.b) ^ 0xffffffff
 472     return h
 473 _augment(ECPrimeCurve, _tmp)
 474
 475 class _tmp:
 476   def __hash__(me):
 477     h = 0x2ac203c5
 478     h ^=   hash(me.field)
 479     h ^= 2*hash(me.a) ^ 0xffffffff
 480     h ^= 5*hash(me.b) ^ 0xffffffff
 481     return h
 482 _augment(ECBinCurve, _tmp)
 483
 484 class _tmp:
 485   def __repr__(me):
 486     if not me: return '%s()' % _clsname(me)
 487     return '%s(%s, %s)' % (_clsname(me), me.ix, me.iy)
 488   def __str__(me):
 489     if not me: return 'inf'
 490     return '(%s, %s)' % (me.ix, me.iy)
 491   def _repr_pretty_(me, pp, cyclep):
 492     if cyclep:
 493       pp.text('...')
 494     elif not me:
 495       pp.text('inf')
 496     else:
 497       ind = _pp_bgroup(pp, '(')
 498       pp.pretty(me.ix); pp.text(','); pp.breakable()
 499       pp.pretty(me.iy)
 500       pp.end_group(ind, ')')
 501 _augment(ECPt, _tmp)
 502
 503 class _tmp:
 504   def __repr__(me):
 505     return '%s(curve = %r, G = %r, r = %s, h = %s)' % \
 506            (_clsname(me), me.curve, me.G, me.r, me.h)
 507   def _repr_pretty_(me, pp, cyclep):
 508     ind = _pp_bgroup_tyname(pp, me)
 509     if cyclep:
 510       pp.text('...')
 511     else:
 512       _pp_kv(pp, 'curve', me.curve); pp.text(','); pp.breakable()
 513       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 514       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 515       _pp_kv(pp, 'h', me.h)
 516     pp.end_group(ind, ')')
 517   def __hash__(me):
 518     h = 0x9bedb8de
 519     h ^=   hash(me.curve)
 520     h ^= 2*hash(me.G) & 0xffffffff
 521     return h
 522   def group(me):
 523     return ECGroup(me)
 524 _augment(ECInfo, _tmp)
 525
 526 class _tmp:
 527   def __repr__(me):
 528     if not me: return '%r()' % (me.curve)
 529     return '%r(%s, %s)' % (me.curve, me.x, me.y)
 530   def __str__(me):
 531     if not me: return 'inf'
 532     return '(%s, %s)' % (me.x, me.y)
 533   def _repr_pretty_(me, pp, cyclep):
 534     if cyclep:
 535       pp.text('...')
 536     elif not me:
 537       pp.text('inf')
 538     else:
 539       ind = _pp_bgroup(pp, '(')
 540       pp.pretty(me.x); pp.text(','); pp.breakable()
 541       pp.pretty(me.y)
 542       pp.end_group(ind, ')')
 543 _augment(ECPtCurve, _tmp)
 544
 545 ###--------------------------------------------------------------------------
 546 ### Key sizes.
 547
 548 class _tmp:
 549   def __repr__(me): return '%s(%d)' % (_clsname(me), me.default)
 550   def check(me, sz): return True
 551   def best(me, sz): return sz
 552 _augment(KeySZAny, _tmp)
 553
 554 class _tmp:
 555   def __repr__(me):
 556     return '%s(%d, %d, %d, %d)' % \
 557            (_clsname(me), me.default, me.min, me.max, me.mod)
 558   def _repr_pretty_(me, pp, cyclep):
 559     ind = _pp_bgroup_tyname(pp, me)
 560     if cyclep:
 561       pp.text('...')
 562     else:
 563       pp.pretty(me.default); pp.text(','); pp.breakable()
 564       pp.pretty(me.min); pp.text(','); pp.breakable()
 565       pp.pretty(me.max); pp.text(','); pp.breakable()
 566       pp.pretty(me.mod)
 567     pp.end_group(ind, ')')
 568   def check(me, sz): return me.min <= sz <= me.max and sz % me.mod == 0
 569   def best(me, sz):
 570     if sz < me.min: raise ValueError, 'key too small'
 571     elif sz > me.max: return me.max
 572     else: return sz - (sz % me.mod)
 573 _augment(KeySZRange, _tmp)
 574
 575 class _tmp:
 576   def __repr__(me): return '%s(%d, %s)' % (_clsname(me), me.default, me.set)
 577   def _repr_pretty_(me, pp, cyclep):
 578     ind = _pp_bgroup_tyname(pp, me)
 579     if cyclep:
 580       pp.text('...')
 581     else:
 582       pp.pretty(me.default); pp.text(','); pp.breakable()
 583       ind1 = _pp_bgroup(pp, '{')
 584       _pp_commas(pp, pp.pretty, me.set)
 585       pp.end_group(ind1, '}')
 586     pp.end_group(ind, ')')
 587   def check(me, sz): return sz in me.set
 588   def best(me, sz):
 589     found = -1
 590     for i in me.set:
 591       if found < i <= sz: found = i
 592     if found < 0: raise ValueError, 'key too small'
 593     return found
 594 _augment(KeySZSet, _tmp)
 595
 596 ###--------------------------------------------------------------------------
 597 ### Key data objects.
 598
 599 class _tmp:
 600   def __repr__(me): return '%s(%r)' % (_clsname(me), me.name)
 601 _augment(KeyFile, _tmp)
 602
 603 class _tmp:
 604   def __repr__(me): return '%s(%r)' % (_clsname(me), me.fulltag)
 605 _augment(Key, _tmp)
 606
 607 class _tmp:
 608   def __repr__(me):
 609     return '%s({%s})' % (_clsname(me),
 610                          ', '.join(['%r: %r' % kv for kv in me.iteritems()]))
 611   def _repr_pretty_(me, pp, cyclep):
 612     ind = _pp_bgroup_tyname(pp, me)
 613     if cyclep: pp.text('...')
 614     else: _pp_dict(pp, me.iteritems())
 615     pp.end_group(ind, ')')
 616 _augment(KeyAttributes, _tmp)
 617
 618 class _tmp:
 619   def __repr__(me):
 620     return '%s(%s, %r)' % (_clsname(me),
 621                            _repr_secret(me._guts(),
 622                                         not (me.flags & KF_NONSECRET)),
 623                            me.writeflags(me.flags))
 624   def _repr_pretty_(me, pp, cyclep):
 625     ind = _pp_bgroup_tyname(pp, me)
 626     if cyclep:
 627       pp.text('...')
 628     else:
 629       _pp_secret(pp, me._guts(), not (me.flags & KF_NONSECRET))
 630       pp.text(','); pp.breakable()
 631       pp.pretty(me.writeflags(me.flags))
 632     pp.end_group(ind, ')')
 633 _augment(KeyData, _tmp)
 634
 635 class _tmp:
 636   def _guts(me): return me.bin
 637 _augment(KeyDataBinary, _tmp)
 638
 639 class _tmp:
 640   def _guts(me): return me.ct
 641 _augment(KeyDataEncrypted, _tmp)
 642
 643 class _tmp:
 644   def _guts(me): return me.mp
 645 _augment(KeyDataMP, _tmp)
 646
 647 class _tmp:
 648   def _guts(me): return me.str
 649 _augment(KeyDataString, _tmp)
 650
 651 class _tmp:
 652   def _guts(me): return me.ecpt
 653 _augment(KeyDataECPt, _tmp)
 654
 655 class _tmp:
 656   def __repr__(me):
 657     return '%s({%s})' % (_clsname(me),
 658                          ', '.join(['%r: %r' % kv for kv in me.iteritems()]))
 659   def _repr_pretty_(me, pp, cyclep):
 660     ind = _pp_bgroup_tyname(pp, me, '({ ')
 661     if cyclep: pp.text('...')
 662     else: _pp_dict(pp, me.iteritems())
 663     pp.end_group(ind, ' })')
 664 _augment(KeyDataStructured, _tmp)
 665
 666 ###--------------------------------------------------------------------------
 667 ### Abstract groups.
 668
 669 class _tmp:
 670   def __repr__(me):
 671     return '%s(p = %s, r = %s, g = %s)' % (_clsname(me), me.p, me.r, me.g)
 672   def _repr_pretty_(me, pp, cyclep):
 673     ind = _pp_bgroup_tyname(pp, me)
 674     if cyclep:
 675       pp.text('...')
 676     else:
 677       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 678       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 679       _pp_kv(pp, 'g', me.g)
 680     pp.end_group(ind, ')')
 681 _augment(FGInfo, _tmp)
 682
 683 class _tmp:
 684   def group(me): return PrimeGroup(me)
 685 _augment(DHInfo, _tmp)
 686
 687 class _tmp:
 688   def group(me): return BinGroup(me)
 689 _augment(BinDHInfo, _tmp)
 690
 691 class _tmp:
 692   def __repr__(me):
 693     return '%s(%r)' % (_clsname(me), me.info)
 694   def _repr_pretty_(me, pp, cyclep):
 695     ind = _pp_bgroup_tyname(pp, me)
 696     if cyclep: pp.text('...')
 697     else: pp.pretty(me.info)
 698     pp.end_group(ind, ')')
 699 _augment(Group, _tmp)
 700
 701 class _tmp:
 702   def __hash__(me):
 703     info = me.info
 704     h = 0xbce3cfe6
 705     h ^=   hash(info.p)
 706     h ^= 2*hash(info.r) & 0xffffffff
 707     h ^= 5*hash(info.g) & 0xffffffff
 708     return h
 709   def _get_geval(me, x): return MP(x)
 710 _augment(PrimeGroup, _tmp)
 711
 712 class _tmp:
 713   def __hash__(me):
 714     info = me.info
 715     h = 0x80695949
 716     h ^=   hash(info.p)
 717     h ^= 2*hash(info.r) & 0xffffffff
 718     h ^= 5*hash(info.g) & 0xffffffff
 719     return h
 720   def _get_geval(me, x): return GF(x)
 721 _augment(BinGroup, _tmp)
 722
 723 class _tmp:
 724   def __hash__(me): return 0x0ec23dab ^ hash(me.info)
 725   def _get_geval(me, x): return x.toec()
 726 _augment(ECGroup, _tmp)
 727
 728 class _tmp:
 729   def __repr__(me):
 730     return '%r(%r)' % (me.group, str(me))
 731   def _repr_pretty_(me, pp, cyclep):
 732     pp.pretty(type(me)._get_geval(me))
 733 _augment(GE, _tmp)
 734
 735 ###--------------------------------------------------------------------------
 736 ### RSA encoding techniques.
 737
 738 class PKCS1Crypt (object):
 739   def __init__(me, ep = '', rng = rand):
 740     me.ep = ep
 741     me.rng = rng
 742   def encode(me, msg, nbits):
 743     return _base._p1crypt_encode(msg, nbits, me.ep, me.rng)
 744   def decode(me, ct, nbits):
 745     return _base._p1crypt_decode(ct, nbits, me.ep, me.rng)
 746
 747 class PKCS1Sig (object):
 748   def __init__(me, ep = '', rng = rand):
 749     me.ep = ep
 750     me.rng = rng
 751   def encode(me, msg, nbits):
 752     return _base._p1sig_encode(msg, nbits, me.ep, me.rng)
 753   def decode(me, msg, sig, nbits):
 754     return _base._p1sig_decode(msg, sig, nbits, me.ep, me.rng)
 755
 756 class OAEP (object):
 757   def __init__(me, mgf = sha_mgf, hash = sha, ep = '', rng = rand):
 758     me.mgf = mgf
 759     me.hash = hash
 760     me.ep = ep
 761     me.rng = rng
 762   def encode(me, msg, nbits):
 763     return _base._oaep_encode(msg, nbits, me.mgf, me.hash, me.ep, me.rng)
 764   def decode(me, ct, nbits):
 765     return _base._oaep_decode(ct, nbits, me.mgf, me.hash, me.ep, me.rng)
 766
 767 class PSS (object):
 768   def __init__(me, mgf = sha_mgf, hash = sha, saltsz = None, rng = rand):
 769     me.mgf = mgf
 770     me.hash = hash
 771     if saltsz is None:
 772       saltsz = hash.hashsz
 773     me.saltsz = saltsz
 774     me.rng = rng
 775   def encode(me, msg, nbits):
 776     return _base._pss_encode(msg, nbits, me.mgf, me.hash, me.saltsz, me.rng)
 777   def decode(me, msg, sig, nbits):
 778     return _base._pss_decode(msg, sig, nbits,
 779                              me.mgf, me.hash, me.saltsz, me.rng)
 780
 781 class _tmp:
 782   def encrypt(me, msg, enc):
 783     return me.pubop(enc.encode(msg, me.n.nbits))
 784   def verify(me, msg, sig, enc):
 785     if msg is None: return enc.decode(msg, me.pubop(sig), me.n.nbits)
 786     try:
 787       x = enc.decode(msg, me.pubop(sig), me.n.nbits)
 788       return x is None or x == msg
 789     except ValueError:
 790       return False
 791   def __repr__(me):
 792     return '%s(n = %r, e = %r)' % (_clsname(me), me.n, me.e)
 793   def _repr_pretty_(me, pp, cyclep):
 794     ind = _pp_bgroup_tyname(pp, me)
 795     if cyclep:
 796       pp.text('...')
 797     else:
 798       _pp_kv(pp, 'n', me.n); pp.text(','); pp.breakable()
 799       _pp_kv(pp, 'e', me.e)
 800     pp.end_group(ind, ')')
 801 _augment(RSAPub, _tmp)
 802
 803 class _tmp:
 804   def decrypt(me, ct, enc): return enc.decode(me.privop(ct), me.n.nbits)
 805   def sign(me, msg, enc): return me.privop(enc.encode(msg, me.n.nbits))
 806   def __repr__(me):
 807     return '%s(n = %r, e = %r, d = %s, ' \
 808       'p = %s, q = %s, dp = %s, dq = %s, q_inv = %s)' % \
 809       (_clsname(me), me.n, me.e,
 810        _repr_secret(me.d), _repr_secret(me.p), _repr_secret(me.q),
 811        _repr_secret(me.dp), _repr_secret(me.dq), _repr_secret(me.q_inv))
 812   def _repr_pretty_(me, pp, cyclep):
 813     ind = _pp_bgroup_tyname(pp, me)
 814     if cyclep:
 815       pp.text('...')
 816     else:
 817       _pp_kv(pp, 'n', me.n); pp.text(','); pp.breakable()
 818       _pp_kv(pp, 'e', me.e); pp.text(','); pp.breakable()
 819       _pp_kv(pp, 'd', me.d, secretp = True); pp.text(','); pp.breakable()
 820       _pp_kv(pp, 'p', me.p, secretp = True); pp.text(','); pp.breakable()
 821       _pp_kv(pp, 'q', me.q, secretp = True); pp.text(','); pp.breakable()
 822       _pp_kv(pp, 'dp', me.dp, secretp = True); pp.text(','); pp.breakable()
 823       _pp_kv(pp, 'dq', me.dq, secretp = True); pp.text(','); pp.breakable()
 824       _pp_kv(pp, 'q_inv', me.q_inv, secretp = True)
 825     pp.end_group(ind, ')')
 826 _augment(RSAPriv, _tmp)
 827
 828 ###--------------------------------------------------------------------------
 829 ### DSA and related schemes.
 830
 831 class _tmp:
 832   def __repr__(me): return '%s(G = %r, p = %r, hash = %r)' % \
 833         (_clsname(me), me.G, me.p, me.hash)
 834   def _repr_pretty_(me, pp, cyclep):
 835     ind = _pp_bgroup_tyname(pp, me)
 836     if cyclep:
 837       pp.text('...')
 838     else:
 839       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 840       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 841       _pp_kv(pp, 'hash', me.hash)
 842     pp.end_group(ind, ')')
 843 _augment(DSAPub, _tmp)
 844 _augment(KCDSAPub, _tmp)
 845
 846 class _tmp:
 847   def __repr__(me): return '%s(G = %r, u = %s, p = %r, hash = %r)' % \
 848       (_clsname(me), me.G, _repr_secret(me.u), me.p, me.hash)
 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, 'G', me.G); pp.text(','); pp.breakable()
 855       _pp_kv(pp, 'u', me.u, True); pp.text(','); pp.breakable()
 856       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 857       _pp_kv(pp, 'hash', me.hash)
 858     pp.end_group(ind, ')')
 859 _augment(DSAPriv, _tmp)
 860 _augment(KCDSAPriv, _tmp)
 861
 862 ###--------------------------------------------------------------------------
 863 ### Bernstein's elliptic curve crypto and related schemes.
 864
 865 X25519_BASE = MP(9).storel(32)
 866 X448_BASE = MP(5).storel(56)
 867
 868 Z128 = ByteString.zero(16)
 869
 870 class _BasePub (object):
 871   def __init__(me, pub, *args, **kw):
 872     if not me._PUBSZ.check(len(pub)): raise ValueError, 'bad public key'
 873     super(_BasePub, me).__init__(*args, **kw)
 874     me.pub = pub
 875   def __repr__(me): return '%s(pub = %r)' % (_clsname(me), me.pub)
 876   def _pp(me, pp): _pp_kv(pp, 'pub', me.pub)
 877   def _repr_pretty_(me, pp, cyclep):
 878     ind = _pp_bgroup_tyname(pp, me)
 879     if cyclep: pp.text('...')
 880     else: me._pp(pp)
 881     pp.end_group(ind, ')')
 882
 883 class _BasePriv (object):
 884   def __init__(me, priv, pub = None, *args, **kw):
 885     if not me._KEYSZ.check(len(priv)): raise ValueError, 'bad private key'
 886     if pub is None: pub = me._pubkey(priv)
 887     super(_BasePriv, me).__init__(pub = pub, *args, **kw)
 888     me.priv = priv
 889   @classmethod
 890   def generate(cls, rng = rand):
 891     return cls(rng.block(cls._KEYSZ.default))
 892   def __repr__(me):
 893     return '%s(priv = %d, pub = %r)' % \
 894         (_clsname(me), _repr_secret(me.priv), me.pub)
 895   def _pp(me, pp):
 896     _pp_kv(pp, 'priv', me.priv, secretp = True); pp.text(','); pp.breakable()
 897     super(_BasePriv, me)._pp(pp)
 898
 899 class _XDHPub (_BasePub):  pass
 900
 901 class _XDHPriv (_BasePriv):
 902   def _pubkey(me, priv): return me._op(priv, me._BASE)
 903   def agree(me, you): return me._op(me.priv, you.pub)
 904   def boxkey(me, recip): return me._hashkey(me.agree(recip))
 905   def box(me, recip, n, m): return secret_box(me.boxkey(recip), n, m)
 906   def unbox(me, recip, n, c): return secret_unbox(me.boxkey(recip), n, c)
 907
 908 class X25519Pub (_XDHPub):
 909   _PUBSZ = KeySZSet(X25519_PUBSZ)
 910   _BASE = X25519_BASE
 911
 912 class X25519Priv (_XDHPriv, X25519Pub):
 913   _KEYSZ = KeySZSet(X25519_KEYSZ)
 914   def _op(me, k, X): return x25519(k, X)
 915   def _hashkey(me, z): return hsalsa20_prf(z, Z128)
 916
 917 class X448Pub (_XDHPub):
 918   _PUBSZ = KeySZSet(X448_PUBSZ)
 919   _BASE = X448_BASE
 920
 921 class X448Priv (_XDHPriv, X448Pub):
 922   _KEYSZ = KeySZSet(X448_KEYSZ)
 923   def _op(me, k, X): return x448(k, X)
 924   def _hashkey(me, z): return Shake256().hash(z).done(salsa20.keysz.default)
 925
 926 class _EdDSAPub (_BasePub):
 927   def beginhash(me): return me._HASH()
 928   def endhash(me, h): return h.done()
 929
 930 class _EdDSAPriv (_BasePriv, _EdDSAPub):
 931   pass
 932
 933 class Ed25519Pub (_EdDSAPub):
 934   _PUBSZ = KeySZSet(ED25519_PUBSZ)
 935   _HASH = sha512
 936   def verify(me, msg, sig, **kw):
 937     return ed25519_verify(me.pub, msg, sig, **kw)
 938
 939 class Ed25519Priv (_EdDSAPriv, Ed25519Pub):
 940   _KEYSZ = KeySZAny(ED25519_KEYSZ)
 941   def _pubkey(me, priv): return ed25519_pubkey(priv)
 942   def sign(me, msg, **kw):
 943     return ed25519_sign(me.priv, msg, pub = me.pub, **kw)
 944
 945 class Ed448Pub (_EdDSAPub):
 946   _PUBSZ = KeySZSet(ED448_PUBSZ)
 947   _HASH = shake256
 948   def verify(me, msg, sig, **kw):
 949     return ed448_verify(me.pub, msg, sig, **kw)
 950
 951 class Ed448Priv (_EdDSAPriv, Ed448Pub):
 952   _KEYSZ = KeySZAny(ED448_KEYSZ)
 953   def _pubkey(me, priv): return ed448_pubkey(priv)
 954   def sign(me, msg, **kw):
 955     return ed448_sign(me.priv, msg, pub = me.pub, **kw)
 956
 957 ###--------------------------------------------------------------------------
 958 ### Built-in named curves and prime groups.
 959
 960 class _groupmap (object):
 961   def __init__(me, map, nth):
 962     me.map = map
 963     me.nth = nth
 964     me._n = max(map.values()) + 1
 965     me.i = me._n*[None]
 966   def __repr__(me):
 967     return '{%s}' % ', '.join(['%r: %r' % kv for kv in me.iteritems()])
 968   def _repr_pretty_(me, pp, cyclep):
 969     ind = _pp_bgroup(pp, '{ ')
 970     if cyclep: pp.text('...')
 971     else: _pp_dict(pp, me.iteritems())
 972     pp.end_group(ind, ' }')
 973   def __len__(me):
 974     return me._n
 975   def __contains__(me, k):
 976     return k in me.map
 977   def __getitem__(me, k):
 978     i = me.map[k]
 979     if me.i[i] is None:
 980       me.i[i] = me.nth(i)
 981     return me.i[i]
 982   def __setitem__(me, k, v):
 983     raise TypeError, "immutable object"
 984   def __iter__(me):
 985     return iter(me.map)
 986   def iterkeys(me):
 987     return iter(me.map)
 988   def itervalues(me):
 989     for k in me:
 990       yield me[k]
 991   def iteritems(me):
 992     for k in me:
 993       yield k, me[k]
 994   def keys(me):
 995     return [k for k in me]
 996   def values(me):
 997     return [me[k] for k in me]
 998   def items(me):
 999     return [(k, me[k]) for k in me]
1000 eccurves = _groupmap(_base._eccurves, ECInfo._curven)
1001 primegroups = _groupmap(_base._pgroups, DHInfo._groupn)
1002 bingroups = _groupmap(_base._bingroups, BinDHInfo._groupn)
1003
1004 ###--------------------------------------------------------------------------
1005 ### Prime number generation.
1006
1007 class PrimeGenEventHandler (object):
1008   def pg_begin(me, ev):
1009     return me.pg_try(ev)
1010   def pg_done(me, ev):
1011     return PGEN_DONE
1012   def pg_abort(me, ev):
1013     return PGEN_TRY
1014   def pg_fail(me, ev):
1015     return PGEN_TRY
1016   def pg_pass(me, ev):
1017     return PGEN_TRY
1018
1019 class SophieGermainStepJump (object):
1020   def pg_begin(me, ev):
1021     me.lf = PrimeFilter(ev.x)
1022     me.hf = me.lf.muladd(2, 1)
1023     return me.cont(ev)
1024   def pg_try(me, ev):
1025     me.step()
1026     return me.cont(ev)
1027   def cont(me, ev):
1028     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
1029       me.step()
1030     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
1031       return PGEN_ABORT
1032     ev.x = me.lf.x
1033     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
1034       return PGEN_DONE
1035     return PGEN_TRY
1036   def pg_done(me, ev):
1037     del me.lf
1038     del me.hf
1039
1040 class SophieGermainStepper (SophieGermainStepJump):
1041   def __init__(me, step):
1042     me.lstep = step;
1043     me.hstep = 2 * step
1044   def step(me):
1045     me.lf.step(me.lstep)
1046     me.hf.step(me.hstep)
1047
1048 class SophieGermainJumper (SophieGermainStepJump):
1049   def __init__(me, jump):
1050     me.ljump = PrimeFilter(jump);
1051     me.hjump = me.ljump.muladd(2, 0)
1052   def step(me):
1053     me.lf.jump(me.ljump)
1054     me.hf.jump(me.hjump)
1055   def pg_done(me, ev):
1056     del me.ljump
1057     del me.hjump
1058     SophieGermainStepJump.pg_done(me, ev)
1059
1060 class SophieGermainTester (object):
1061   def __init__(me):
1062     pass
1063   def pg_begin(me, ev):
1064     me.lr = RabinMiller(ev.x)
1065     me.hr = RabinMiller(2 * ev.x + 1)
1066   def pg_try(me, ev):
1067     lst = me.lr.test(ev.rng.range(me.lr.x))
1068     if lst != PGEN_PASS and lst != PGEN_DONE:
1069       return lst
1070     rst = me.hr.test(ev.rng.range(me.hr.x))
1071     if rst != PGEN_PASS and rst != PGEN_DONE:
1072       return rst
1073     if lst == PGEN_DONE and rst == PGEN_DONE:
1074       return PGEN_DONE
1075     return PGEN_PASS
1076   def pg_done(me, ev):
1077     del me.lr
1078     del me.hr
1079
1080 class PrimitiveStepper (PrimeGenEventHandler):
1081   def __init__(me):
1082     pass
1083   def pg_try(me, ev):
1084     ev.x = me.i.next()
1085     return PGEN_TRY
1086   def pg_begin(me, ev):
1087     me.i = iter(smallprimes)
1088     return me.pg_try(ev)
1089
1090 class PrimitiveTester (PrimeGenEventHandler):
1091   def __init__(me, mod, hh = [], exp = None):
1092     me.mod = MPMont(mod)
1093     me.exp = exp
1094     me.hh = hh
1095   def pg_try(me, ev):
1096     x = ev.x
1097     if me.exp is not None:
1098       x = me.mod.exp(x, me.exp)
1099       if x == 1: return PGEN_FAIL
1100     for h in me.hh:
1101       if me.mod.exp(x, h) == 1: return PGEN_FAIL
1102     ev.x = x
1103     return PGEN_DONE
1104
1105 class SimulStepper (PrimeGenEventHandler):
1106   def __init__(me, mul = 2, add = 1, step = 2):
1107     me.step = step
1108     me.mul = mul
1109     me.add = add
1110   def _stepfn(me, step):
1111     if step <= 0:
1112       raise ValueError, 'step must be positive'
1113     if step <= MPW_MAX:
1114       return lambda f: f.step(step)
1115     j = PrimeFilter(step)
1116     return lambda f: f.jump(j)
1117   def pg_begin(me, ev):
1118     x = ev.x
1119     me.lf = PrimeFilter(x)
1120     me.hf = PrimeFilter(x * me.mul + me.add)
1121     me.lstep = me._stepfn(me.step)
1122     me.hstep = me._stepfn(me.step * me.mul)
1123     SimulStepper._cont(me, ev)
1124   def pg_try(me, ev):
1125     me._step()
1126     me._cont(ev)
1127   def _step(me):
1128     me.lstep(me.lf)
1129     me.hstep(me.hf)
1130   def _cont(me, ev):
1131     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
1132       me._step()
1133     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
1134       return PGEN_ABORT
1135     ev.x = me.lf.x
1136     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
1137       return PGEN_DONE
1138     return PGEN_TRY
1139   def pg_done(me, ev):
1140     del me.lf
1141     del me.hf
1142     del me.lstep
1143     del me.hstep
1144
1145 class SimulTester (PrimeGenEventHandler):
1146   def __init__(me, mul = 2, add = 1):
1147     me.mul = mul
1148     me.add = add
1149   def pg_begin(me, ev):
1150     x = ev.x
1151     me.lr = RabinMiller(x)
1152     me.hr = RabinMiller(x * me.mul + me.add)
1153   def pg_try(me, ev):
1154     lst = me.lr.test(ev.rng.range(me.lr.x))
1155     if lst != PGEN_PASS and lst != PGEN_DONE:
1156       return lst
1157     rst = me.hr.test(ev.rng.range(me.hr.x))
1158     if rst != PGEN_PASS and rst != PGEN_DONE:
1159       return rst
1160     if lst == PGEN_DONE and rst == PGEN_DONE:
1161       return PGEN_DONE
1162     return PGEN_PASS
1163   def pg_done(me, ev):
1164     del me.lr
1165     del me.hr
1166
1167 def sgprime(start, step = 2, name = 'p', event = pgen_nullev, nsteps = 0):
1168   start = MP(start)
1169   return pgen(start, name, SimulStepper(step = step), SimulTester(), event,
1170               nsteps, RabinMiller.iters(start.nbits))
1171
1172 def findprimitive(mod, hh = [], exp = None, name = 'g', event = pgen_nullev):
1173   return pgen(0, name, PrimitiveStepper(), PrimitiveTester(mod, hh, exp),
1174               event, 0, 1)
1175
1176 def kcdsaprime(pbits, qbits, rng = rand,
1177                event = pgen_nullev, name = 'p', nsteps = 0):
1178   hbits = pbits - qbits
1179   h = pgen(rng.mp(hbits, 1), name + ' [h]',
1180            PrimeGenStepper(2), PrimeGenTester(),
1181            event, nsteps, RabinMiller.iters(hbits))
1182   q = pgen(rng.mp(qbits, 1), name, SimulStepper(2 * h, 1, 2),
1183            SimulTester(2 * h, 1), event, nsteps, RabinMiller.iters(qbits))
1184   p = 2 * q * h + 1
1185   return p, q, h
1186
1187 #----- That's all, folks ----------------------------------------------------