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 if _sys.version_info >= (3,): from . import _base
  59 else: import _base
  60
  61 if _odlflags >= 0:
  62   _sys.setdlopenflags(_odlflags)
  63
  64 del _dlflags, _odlflags
  65
  66 ###--------------------------------------------------------------------------
  67 ### Basic stuff.
  68
  69 ## For the benefit of the default keyreporter, we need the program name.
  70 _base._ego(_sys.argv[0])
  71
  72 ## Register our module.
  73 _base._set_home_module(_sys.modules[__name__])
  74 def default_lostexchook(why, ty, val, tb):
  75   """`catacomb.lostexchook(WHY, TY, VAL, TB)' reports lost exceptions."""
  76   _sys.stderr.write("\n\n!!! LOST EXCEPTION: %s\n" % why)
  77   _sys.excepthook(ty, val, tb)
  78   _sys.stderr.write("\n")
  79 lostexchook = default_lostexchook
  80
  81 ## Text/binary conversions.
  82 if _sys.version_info >= (3,):
  83   def _bin(s): return s.encode('iso8859-1')
  84 else:
  85   def _bin(s): return s
  86
  87 ## Iterating over dictionaries.
  88 if _sys.version_info >= (3,):
  89   def _iteritems(dict): return dict.items()
  90   def _itervalues(dict): return dict.values()
  91 else:
  92   def _iteritems(dict): return dict.iteritems()
  93   def _itervalues(dict): return dict.itervalues()
  94
  95 ## The built-in bignum type.
  96 try: long
  97 except NameError: _long = int
  98 else: _long = long
  99
 100 ## How to fix a name back into the right identifier.  Alas, the rules are not
 101 ## consistent.
 102 def _fixname(name):
 103
 104   ## Hyphens consistently become underscores.
 105   name = name.replace('-', '_')
 106
 107   ## But slashes might become underscores or just vanish.
 108   if name.startswith('salsa20'): name = name.replace('/', '')
 109   else: name = name.replace('/', '_')
 110
 111   ## Done.
 112   return name
 113
 114 ## Initialize the module.  Drag in the static methods of the various
 115 ## classes; create names for the various known crypto algorithms.
 116 def _init():
 117   d = globals()
 118   b = _base.__dict__;
 119   for i in b:
 120     if i[0] != '_':
 121       d[i] = b[i];
 122   for i in [gcciphers, gcaeads, gchashes, gcmacs, gcprps]:
 123     for c in _itervalues(i):
 124       d[_fixname(c.name)] = c
 125   for c in _itervalues(gccrands):
 126     d[_fixname(c.name + 'rand')] = c
 127 _init()
 128
 129 ## A handy function for our work: add the methods of a named class to an
 130 ## existing class.  This is how we write the Python-implemented parts of our
 131 ## mostly-C types.
 132 def _augment(c, cc):
 133   for i in cc.__dict__:
 134     a = cc.__dict__[i]
 135     if type(a) is _types.MethodType:
 136       a = a.im_func
 137     elif type(a) not in (_types.FunctionType, staticmethod, classmethod):
 138       continue
 139     setattr(c, i, a)
 140
 141 ## Parsing functions tend to return the object parsed and the remainder of
 142 ## the input.  This checks that the remainder is input and, if so, returns
 143 ## just the object.
 144 def _checkend(r):
 145   x, rest = r
 146   if rest != '':
 147     raise SyntaxError('junk at end of string')
 148   return x
 149
 150 ## Some pretty-printing utilities.
 151 PRINT_SECRETS = False
 152 def _clsname(me): return type(me).__name__
 153 def _repr_secret(thing, secretp = True):
 154   if not secretp or PRINT_SECRETS: return repr(thing)
 155   else: return '#<SECRET>'
 156 def _pp_str(me, pp, cyclep): pp.text(cyclep and '...' or str(me))
 157 def _pp_secret(pp, thing, secretp = True):
 158   if not secretp or PRINT_SECRETS: pp.pretty(thing)
 159   else: pp.text('#<SECRET>')
 160 def _pp_bgroup(pp, text):
 161   ind = len(text)
 162   pp.begin_group(ind, text)
 163   return ind
 164 def _pp_bgroup_tyname(pp, obj, open = '('):
 165   return _pp_bgroup(pp, _clsname(obj) + open)
 166 def _pp_kv(pp, k, v, secretp = False):
 167   ind = _pp_bgroup(pp, k + ' = ')
 168   _pp_secret(pp, v, secretp)
 169   pp.end_group(ind, '')
 170 def _pp_commas(pp, printfn, items):
 171   firstp = True
 172   for i in items:
 173     if firstp: firstp = False
 174     else: pp.text(','); pp.breakable()
 175     printfn(i)
 176 def _pp_dict(pp, items):
 177   def p(kv):
 178     k, v = kv
 179     pp.begin_group(0)
 180     pp.pretty(k)
 181     pp.text(':')
 182     pp.begin_group(2)
 183     pp.breakable()
 184     pp.pretty(v)
 185     pp.end_group(2)
 186     pp.end_group(0)
 187   _pp_commas(pp, p, items)
 188
 189 ###--------------------------------------------------------------------------
 190 ### Mappings.
 191
 192 if _sys.version_info >= (3,):
 193   class _tmp:
 194     def __str__(me): return '%s(%r)' % (type(me).__name__, list(me))
 195     __repr__ = __str__
 196     def _repr_pretty_(me, pp, cyclep):
 197       ind = _pp_bgroup_tyname(pp, me, '([')
 198       _pp_commas(pp, pp.pretty, me)
 199       pp.end_group(ind, '])')
 200   _augment(_base._KeyView, _tmp)
 201   _augment(_base._ValueView, _tmp)
 202   _augment(_base._ItemView, _tmp)
 203
 204 ###--------------------------------------------------------------------------
 205 ### Bytestrings.
 206
 207 class _tmp:
 208   def fromhex(x):
 209     return ByteString(_unhexify(x))
 210   fromhex = staticmethod(fromhex)
 211   if _sys.version_info >= (3,):
 212     def hex(me): return _hexify(me).decode()
 213   else:
 214     def hex(me): return _hexify(me)
 215     __hex__ = hex
 216   def __repr__(me):
 217     return 'bytes(%r)' % me.hex()
 218 _augment(ByteString, _tmp)
 219 ByteString.__hash__ = str.__hash__
 220 bytes = ByteString.fromhex
 221
 222 ###--------------------------------------------------------------------------
 223 ### Symmetric encryption.
 224
 225 class _tmp:
 226   def encrypt(me, n, m, tsz = None, h = ByteString.zero(0)):
 227     if tsz is None: tsz = me.__class__.tagsz.default
 228     e = me.enc(n, len(h), len(m), tsz)
 229     if not len(h): a = None
 230     else: a = e.aad().hash(h)
 231     c0 = e.encrypt(m)
 232     c1, t = e.done(aad = a)
 233     return c0 + c1, t
 234   def decrypt(me, n, c, t, h = ByteString.zero(0)):
 235     d = me.dec(n, len(h), len(c), len(t))
 236     if not len(h): a = None
 237     else: a = d.aad().hash(h)
 238     m = d.decrypt(c)
 239     m += d.done(t, aad = a)
 240     return m
 241 _augment(GAEKey, _tmp)
 242
 243 ###--------------------------------------------------------------------------
 244 ### Hashing.
 245
 246 class _tmp:
 247   def check(me, h):
 248     hh = me.done()
 249     return ctstreq(h, hh)
 250 _augment(GHash, _tmp)
 251 _augment(Poly1305Hash, _tmp)
 252
 253 class _tmp:
 254   def check(me, h):
 255     return ctstreq(h, me.done(len(h)))
 256 _augment(Shake, _tmp)
 257
 258 KMAC128.keysz = KeySZAny(16); KMAC128.tagsz = 16
 259 KMAC256.keysz = KeySZAny(32); KMAC256.tagsz = 32
 260
 261 ###--------------------------------------------------------------------------
 262 ### NaCl `secretbox'.
 263
 264 def secret_box(k, n, m):
 265   y, t = salsa20_naclbox(k).encrypt(n, m)
 266   return t + y
 267
 268 def secret_unbox(k, n, c):
 269   tsz = poly1305.tagsz
 270   return salsa20_naclbox(k).decrypt(n, c[tsz:], c[0:tsz])
 271
 272 ###--------------------------------------------------------------------------
 273 ### Multiprecision integers and binary polynomials.
 274
 275 def _split_rat(x):
 276   if isinstance(x, BaseRat): return x._n, x._d
 277   else: return x, 1
 278 class BaseRat (object):
 279   """Base class implementing fields of fractions over Euclidean domains."""
 280   def __new__(cls, a, b):
 281     a, b = cls.RING(a), cls.RING(b)
 282     q, r = divmod(a, b)
 283     if r == 0: return q
 284     g = b.gcd(r)
 285     me = super(BaseRat, cls).__new__(cls)
 286     me._n = a//g
 287     me._d = b//g
 288     return me
 289   @property
 290   def numer(me): return me._n
 291   @property
 292   def denom(me): return me._d
 293   def __str__(me): return '%s/%s' % (me._n, me._d)
 294   def __repr__(me): return '%s(%s, %s)' % (_clsname(me), me._n, me._d)
 295   _repr_pretty_ = _pp_str
 296
 297   def __add__(me, you):
 298     n, d = _split_rat(you)
 299     return type(me)(me._n*d + n*me._d, d*me._d)
 300   __radd__ = __add__
 301   def __sub__(me, you):
 302     n, d = _split_rat(you)
 303     return type(me)(me._n*d - n*me._d, d*me._d)
 304   def __rsub__(me, you):
 305     n, d = _split_rat(you)
 306     return type(me)(n*me._d - me._n*d, d*me._d)
 307   def __mul__(me, you):
 308     n, d = _split_rat(you)
 309     return type(me)(me._n*n, me._d*d)
 310   __rmul__ = __mul__
 311   def __truediv__(me, you):
 312     n, d = _split_rat(you)
 313     return type(me)(me._n*d, me._d*n)
 314   def __rtruediv__(me, you):
 315     n, d = _split_rat(you)
 316     return type(me)(me._d*n, me._n*d)
 317   if _sys.version_info < (3,):
 318     __div__ = __truediv__
 319     __rdiv__ = __rtruediv__
 320   def _order(me, you, op):
 321     n, d = _split_rat(you)
 322     return op(me._n*d, n*me._d)
 323   def __eq__(me, you): return me._order(you, lambda x, y: x == y)
 324   def __ne__(me, you): return me._order(you, lambda x, y: x != y)
 325   def __le__(me, you): return me._order(you, lambda x, y: x <= y)
 326   def __lt__(me, you): return me._order(you, lambda x, y: x <  y)
 327   def __gt__(me, you): return me._order(you, lambda x, y: x >  y)
 328   def __ge__(me, you): return me._order(you, lambda x, y: x >= y)
 329
 330 class IntRat (BaseRat):
 331   RING = MP
 332   def __new__(cls, a, b):
 333     if isinstance(a, float) or isinstance(b, float): return a/b
 334     return super(IntRat, cls).__new__(cls, a, b)
 335   def __float__(me): return float(me._n)/float(me._d)
 336
 337 class GFRat (BaseRat):
 338   RING = GF
 339
 340 class _tmp:
 341   def negp(x): return x < 0
 342   def posp(x): return x > 0
 343   def zerop(x): return x == 0
 344   def oddp(x): return x.testbit(0)
 345   def evenp(x): return not x.testbit(0)
 346   def mont(x): return MPMont(x)
 347   def barrett(x): return MPBarrett(x)
 348   def reduce(x): return MPReduce(x)
 349   def __truediv__(me, you):
 350     if isinstance(you, float): return _long(me)/you
 351     else: return IntRat(me, you)
 352   def __rtruediv__(me, you):
 353     if isinstance(you, float): return you/_long(me)
 354     else: return IntRat(you, me)
 355   if _sys.version_info < (3,):
 356     __div__ = __truediv__
 357     __rdiv__ = __rtruediv__
 358   _repr_pretty_ = _pp_str
 359 _augment(MP, _tmp)
 360
 361 class _tmp:
 362   def zerop(x): return x == 0
 363   def reduce(x): return GFReduce(x)
 364   def trace(x, y): return x.reduce().trace(y)
 365   def halftrace(x, y): return x.reduce().halftrace(y)
 366   def modsqrt(x, y): return x.reduce().sqrt(y)
 367   def quadsolve(x, y): return x.reduce().quadsolve(y)
 368   def __truediv__(me, you): return GFRat(me, you)
 369   def __rtruediv__(me, you): return GFRat(you, me)
 370   if _sys.version_info < (3,):
 371     __div__ = __truediv__
 372     __rdiv__ = __rtruediv__
 373   _repr_pretty_ = _pp_str
 374 _augment(GF, _tmp)
 375
 376 class _tmp:
 377   def product(*arg):
 378     'product(ITERABLE) or product(I, ...) -> PRODUCT'
 379     return MPMul(*arg).done()
 380   product = staticmethod(product)
 381 _augment(MPMul, _tmp)
 382
 383 ###--------------------------------------------------------------------------
 384 ### Abstract fields.
 385
 386 class _tmp:
 387   def fromstring(str): return _checkend(Field.parse(str))
 388   fromstring = staticmethod(fromstring)
 389 _augment(Field, _tmp)
 390
 391 class _tmp:
 392   def __repr__(me): return '%s(%s)' % (_clsname(me), me.p)
 393   def __hash__(me): return 0x114401de ^ hash(me.p)
 394   def _repr_pretty_(me, pp, cyclep):
 395     ind = _pp_bgroup_tyname(pp, me)
 396     if cyclep: pp.text('...')
 397     else: pp.pretty(me.p)
 398     pp.end_group(ind, ')')
 399   def ec(me, a, b): return ECPrimeProjCurve(me, a, b)
 400 _augment(PrimeField, _tmp)
 401
 402 class _tmp:
 403   def __repr__(me): return '%s(%#x)' % (_clsname(me), me.p)
 404   def ec(me, a, b): return ECBinProjCurve(me, a, b)
 405   def _repr_pretty_(me, pp, cyclep):
 406     ind = _pp_bgroup_tyname(pp, me)
 407     if cyclep: pp.text('...')
 408     else: pp.text('%#x' % me.p)
 409     pp.end_group(ind, ')')
 410 _augment(BinField, _tmp)
 411
 412 class _tmp:
 413   def __hash__(me): return 0x23e4701c ^ hash(me.p)
 414 _augment(BinPolyField, _tmp)
 415
 416 class _tmp:
 417   def __hash__(me):
 418     h = 0x9a7d6240
 419     h ^=   hash(me.p)
 420     h ^= 2*hash(me.beta) & 0xffffffff
 421     return h
 422 _augment(BinNormField, _tmp)
 423
 424 class _tmp:
 425   def __str__(me): return str(me.value)
 426   def __repr__(me): return '%s(%s)' % (repr(me.field), repr(me.value))
 427   _repr_pretty_ = _pp_str
 428 _augment(FE, _tmp)
 429
 430 ###--------------------------------------------------------------------------
 431 ### Elliptic curves.
 432
 433 class _tmp:
 434   def __repr__(me):
 435     return '%s(%r, %s, %s)' % (_clsname(me), me.field, me.a, me.b)
 436   def _repr_pretty_(me, pp, cyclep):
 437     ind = _pp_bgroup_tyname(pp, me)
 438     if cyclep:
 439       pp.text('...')
 440     else:
 441       pp.pretty(me.field); pp.text(','); pp.breakable()
 442       pp.pretty(me.a); pp.text(','); pp.breakable()
 443       pp.pretty(me.b)
 444     pp.end_group(ind, ')')
 445   def frombuf(me, s):
 446     return ecpt.frombuf(me, s)
 447   def fromraw(me, s):
 448     return ecpt.fromraw(me, s)
 449   def pt(me, *args):
 450     return me(*args)
 451 _augment(ECCurve, _tmp)
 452
 453 class _tmp:
 454   def __hash__(me):
 455     h = 0x6751d341
 456     h ^=   hash(me.field)
 457     h ^= 2*hash(me.a) ^ 0xffffffff
 458     h ^= 5*hash(me.b) ^ 0xffffffff
 459     return h
 460 _augment(ECPrimeCurve, _tmp)
 461
 462 class _tmp:
 463   def __hash__(me):
 464     h = 0x2ac203c5
 465     h ^=   hash(me.field)
 466     h ^= 2*hash(me.a) ^ 0xffffffff
 467     h ^= 5*hash(me.b) ^ 0xffffffff
 468     return h
 469 _augment(ECBinCurve, _tmp)
 470
 471 class _tmp:
 472   def __repr__(me):
 473     if not me: return '%s()' % _clsname(me)
 474     return '%s(%s, %s)' % (_clsname(me), me.ix, me.iy)
 475   def __str__(me):
 476     if not me: return 'inf'
 477     return '(%s, %s)' % (me.ix, me.iy)
 478   def _repr_pretty_(me, pp, cyclep):
 479     if cyclep:
 480       pp.text('...')
 481     elif not me:
 482       pp.text('inf')
 483     else:
 484       ind = _pp_bgroup(pp, '(')
 485       pp.pretty(me.ix); pp.text(','); pp.breakable()
 486       pp.pretty(me.iy)
 487       pp.end_group(ind, ')')
 488 _augment(ECPt, _tmp)
 489
 490 class _tmp:
 491   def __repr__(me):
 492     return '%s(curve = %r, G = %r, r = %s, h = %s)' % \
 493            (_clsname(me), me.curve, me.G, me.r, me.h)
 494   def _repr_pretty_(me, pp, cyclep):
 495     ind = _pp_bgroup_tyname(pp, me)
 496     if cyclep:
 497       pp.text('...')
 498     else:
 499       _pp_kv(pp, 'curve', me.curve); pp.text(','); pp.breakable()
 500       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 501       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 502       _pp_kv(pp, 'h', me.h)
 503     pp.end_group(ind, ')')
 504   def __hash__(me):
 505     h = 0x9bedb8de
 506     h ^=   hash(me.curve)
 507     h ^= 2*hash(me.G) & 0xffffffff
 508     return h
 509   def group(me):
 510     return ECGroup(me)
 511 _augment(ECInfo, _tmp)
 512
 513 class _tmp:
 514   def __repr__(me):
 515     if not me: return '%r()' % (me.curve)
 516     return '%r(%s, %s)' % (me.curve, me.x, me.y)
 517   def __str__(me):
 518     if not me: return 'inf'
 519     return '(%s, %s)' % (me.x, me.y)
 520   def _repr_pretty_(me, pp, cyclep):
 521     if cyclep:
 522       pp.text('...')
 523     elif not me:
 524       pp.text('inf')
 525     else:
 526       ind = _pp_bgroup(pp, '(')
 527       pp.pretty(me.x); pp.text(','); pp.breakable()
 528       pp.pretty(me.y)
 529       pp.end_group(ind, ')')
 530 _augment(ECPtCurve, _tmp)
 531
 532 ###--------------------------------------------------------------------------
 533 ### Key sizes.
 534
 535 class _tmp:
 536   def __repr__(me): return '%s(%d)' % (_clsname(me), me.default)
 537   def check(me, sz): return True
 538   def best(me, sz): return sz
 539   def pad(me, sz): return sz
 540 _augment(KeySZAny, _tmp)
 541
 542 class _tmp:
 543   def __repr__(me):
 544     return '%s(%d, %d, %d, %d)' % \
 545            (_clsname(me), me.default, me.min, me.max, me.mod)
 546   def _repr_pretty_(me, pp, cyclep):
 547     ind = _pp_bgroup_tyname(pp, me)
 548     if cyclep:
 549       pp.text('...')
 550     else:
 551       pp.pretty(me.default); pp.text(','); pp.breakable()
 552       pp.pretty(me.min); pp.text(','); pp.breakable()
 553       pp.pretty(me.max); pp.text(','); pp.breakable()
 554       pp.pretty(me.mod)
 555     pp.end_group(ind, ')')
 556   def check(me, sz): return me.min <= sz <= me.max and sz%me.mod == 0
 557   def best(me, sz):
 558     if sz < me.min: raise ValueError('key too small')
 559     elif me.max is not None and sz > me.max: return me.max
 560     else: return sz - sz%me.mod
 561   def pad(me, sz):
 562     if me.max is not None and sz > me.max: raise ValueError('key too large')
 563     elif sz < me.min: return me.min
 564     else: sz += me.mod - 1; return sz - sz%me.mod
 565 _augment(KeySZRange, _tmp)
 566
 567 class _tmp:
 568   def __repr__(me): return '%s(%d, %s)' % (_clsname(me), me.default, me.set)
 569   def _repr_pretty_(me, pp, cyclep):
 570     ind = _pp_bgroup_tyname(pp, me)
 571     if cyclep:
 572       pp.text('...')
 573     else:
 574       pp.pretty(me.default); pp.text(','); pp.breakable()
 575       ind1 = _pp_bgroup(pp, '{')
 576       _pp_commas(pp, pp.pretty, me.set)
 577       pp.end_group(ind1, '}')
 578     pp.end_group(ind, ')')
 579   def check(me, sz): return sz in me.set
 580   def best(me, sz):
 581     found = -1
 582     for i in me.set:
 583       if found < i <= sz: found = i
 584     if found < 0: raise ValueError('key too small')
 585     return found
 586   def pad(me, sz):
 587     found = -1
 588     for i in me.set:
 589       if sz <= i and (found == -1 or i < found): found = i
 590     if found < 0: raise ValueError('key too large')
 591     return found
 592 _augment(KeySZSet, _tmp)
 593
 594 ###--------------------------------------------------------------------------
 595 ### Key data objects.
 596
 597 class _tmp:
 598   def merge(me, file, report = None):
 599     """KF.merge(FILE, [report = <built-in-reporter>])"""
 600     name = file.name
 601     lno = 1
 602     for line in file:
 603       me.mergeline(name, lno, line, report)
 604       lno += 1
 605     return me
 606   def __repr__(me): return '%s(%r)' % (_clsname(me), me.name)
 607 _augment(KeyFile, _tmp)
 608
 609 class _tmp:
 610   def extract(me, file, filter = ''):
 611     """KEY.extract(FILE, [filter = <any>])"""
 612     line = me.extractline(filter)
 613     file.write(line)
 614     return me
 615   def __repr__(me): return '%s(%r)' % (_clsname(me), me.fulltag)
 616 _augment(Key, _tmp)
 617
 618 class _tmp:
 619   def __repr__(me):
 620     return '%s({%s})' % (_clsname(me),
 621                          ', '.join(['%r: %r' % kv for kv in _iteritems(me)()]))
 622   def _repr_pretty_(me, pp, cyclep):
 623     ind = _pp_bgroup_tyname(pp, me)
 624     if cyclep: pp.text('...')
 625     else: _pp_dict(pp, _iteritems(me))
 626     pp.end_group(ind, ')')
 627 _augment(KeyAttributes, _tmp)
 628
 629 class _tmp:
 630   def __repr__(me):
 631     return '%s(%s, %r)' % (_clsname(me),
 632                            _repr_secret(me._guts(),
 633                                         not (me.flags & KF_NONSECRET)),
 634                            me.writeflags(me.flags))
 635   def _repr_pretty_(me, pp, cyclep):
 636     ind = _pp_bgroup_tyname(pp, me)
 637     if cyclep:
 638       pp.text('...')
 639     else:
 640       _pp_secret(pp, me._guts(), not (me.flags & KF_NONSECRET))
 641       pp.text(','); pp.breakable()
 642       pp.pretty(me.writeflags(me.flags))
 643     pp.end_group(ind, ')')
 644   def __hash__(me): return me._HASHBASE ^ hash(me._guts())
 645   def __eq__(me, kd):
 646     return type(me) == type(kd) and \
 647       me._guts() == kd._guts() and \
 648       me.flags == kd.flags
 649   def __ne__(me, kd):
 650     return not me == kd
 651 _augment(KeyData, _tmp)
 652
 653 class _tmp:
 654   def _guts(me): return me.bin
 655   def __eq__(me, kd):
 656     return isinstance(kd, KeyDataBinary) and me.bin == kd.bin
 657 _augment(KeyDataBinary, _tmp)
 658 KeyDataBinary._HASHBASE = 0x961755c3
 659
 660 class _tmp:
 661   def _guts(me): return me.ct
 662 _augment(KeyDataEncrypted, _tmp)
 663 KeyDataEncrypted._HASHBASE = 0xffe000d4
 664
 665 class _tmp:
 666   def _guts(me): return me.mp
 667 _augment(KeyDataMP, _tmp)
 668 KeyDataMP._HASHBASE = 0x1cb64d69
 669
 670 class _tmp:
 671   def _guts(me): return me.str
 672 _augment(KeyDataString, _tmp)
 673 KeyDataString._HASHBASE = 0x349c33ea
 674
 675 class _tmp:
 676   def _guts(me): return me.ecpt
 677 _augment(KeyDataECPt, _tmp)
 678 KeyDataECPt._HASHBASE = 0x2509718b
 679
 680 class _tmp:
 681   def __repr__(me):
 682     return '%s({%s})' % (_clsname(me),
 683                          ', '.join(['%r: %r' % kv for kv in _iteritems(me)]))
 684   def _repr_pretty_(me, pp, cyclep):
 685     ind = _pp_bgroup_tyname(pp, me, '({ ')
 686     if cyclep: pp.text('...')
 687     else: _pp_dict(pp, _iteritems(me))
 688     pp.end_group(ind, ' })')
 689   def __hash__(me):
 690     h = me._HASHBASE
 691     for k, v in _iteritems(me):
 692       h = ((h << 1) ^ 3*hash(k) ^ 5*hash(v))&0xffffffff
 693     return h
 694   def __eq__(me, kd):
 695     if type(me) != type(kd) or me.flags != kd.flags or len(me) != len(kd):
 696       return False
 697     for k, v in _iteritems(me):
 698       try: vv = kd[k]
 699       except KeyError: return False
 700       if v != vv: return False
 701     return True
 702 _augment(KeyDataStructured, _tmp)
 703 KeyDataStructured._HASHBASE = 0x85851b21
 704
 705 ###--------------------------------------------------------------------------
 706 ### Abstract groups.
 707
 708 class _tmp:
 709   def __repr__(me):
 710     return '%s(p = %s, r = %s, g = %s)' % (_clsname(me), me.p, me.r, me.g)
 711   def _repr_pretty_(me, pp, cyclep):
 712     ind = _pp_bgroup_tyname(pp, me)
 713     if cyclep:
 714       pp.text('...')
 715     else:
 716       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 717       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 718       _pp_kv(pp, 'g', me.g)
 719     pp.end_group(ind, ')')
 720 _augment(FGInfo, _tmp)
 721
 722 class _tmp:
 723   def group(me): return PrimeGroup(me)
 724 _augment(DHInfo, _tmp)
 725
 726 class _tmp:
 727   def group(me): return BinGroup(me)
 728 _augment(BinDHInfo, _tmp)
 729
 730 class _tmp:
 731   def __repr__(me):
 732     return '%s(%r)' % (_clsname(me), me.info)
 733   def _repr_pretty_(me, pp, cyclep):
 734     ind = _pp_bgroup_tyname(pp, me)
 735     if cyclep: pp.text('...')
 736     else: pp.pretty(me.info)
 737     pp.end_group(ind, ')')
 738 _augment(Group, _tmp)
 739
 740 class _tmp:
 741   def __hash__(me):
 742     info = me.info
 743     h = 0xbce3cfe6
 744     h ^=   hash(info.p)
 745     h ^= 2*hash(info.r) & 0xffffffff
 746     h ^= 5*hash(info.g) & 0xffffffff
 747     return h
 748   def _get_geval(me, x): return MP(x)
 749 _augment(PrimeGroup, _tmp)
 750
 751 class _tmp:
 752   def __hash__(me):
 753     info = me.info
 754     h = 0x80695949
 755     h ^=   hash(info.p)
 756     h ^= 2*hash(info.r) & 0xffffffff
 757     h ^= 5*hash(info.g) & 0xffffffff
 758     return h
 759   def _get_geval(me, x): return GF(x)
 760 _augment(BinGroup, _tmp)
 761
 762 class _tmp:
 763   def __hash__(me): return 0x0ec23dab ^ hash(me.info)
 764   def _get_geval(me, x): return x.toec()
 765 _augment(ECGroup, _tmp)
 766
 767 class _tmp:
 768   def __repr__(me):
 769     return '%r(%r)' % (me.group, str(me))
 770   def _repr_pretty_(me, pp, cyclep):
 771     pp.pretty(type(me)._get_geval(me))
 772 _augment(GE, _tmp)
 773
 774 ###--------------------------------------------------------------------------
 775 ### RSA encoding techniques.
 776
 777 class PKCS1Crypt (object):
 778   def __init__(me, ep = _bin(''), rng = rand):
 779     me.ep = ep
 780     me.rng = rng
 781   def encode(me, msg, nbits):
 782     return _base._p1crypt_encode(msg, nbits, me.ep, me.rng)
 783   def decode(me, ct, nbits):
 784     return _base._p1crypt_decode(ct, nbits, me.ep, me.rng)
 785
 786 class PKCS1Sig (object):
 787   def __init__(me, ep = _bin(''), rng = rand):
 788     me.ep = ep
 789     me.rng = rng
 790   def encode(me, msg, nbits):
 791     return _base._p1sig_encode(msg, nbits, me.ep, me.rng)
 792   def decode(me, msg, sig, nbits):
 793     return _base._p1sig_decode(msg, sig, nbits, me.ep, me.rng)
 794
 795 class OAEP (object):
 796   def __init__(me, mgf = sha_mgf, hash = sha, ep = _bin(''), rng = rand):
 797     me.mgf = mgf
 798     me.hash = hash
 799     me.ep = ep
 800     me.rng = rng
 801   def encode(me, msg, nbits):
 802     return _base._oaep_encode(msg, nbits, me.mgf, me.hash, me.ep, me.rng)
 803   def decode(me, ct, nbits):
 804     return _base._oaep_decode(ct, nbits, me.mgf, me.hash, me.ep, me.rng)
 805
 806 class PSS (object):
 807   def __init__(me, mgf = sha_mgf, hash = sha, saltsz = None, rng = rand):
 808     me.mgf = mgf
 809     me.hash = hash
 810     if saltsz is None:
 811       saltsz = hash.hashsz
 812     me.saltsz = saltsz
 813     me.rng = rng
 814   def encode(me, msg, nbits):
 815     return _base._pss_encode(msg, nbits, me.mgf, me.hash, me.saltsz, me.rng)
 816   def decode(me, msg, sig, nbits):
 817     return _base._pss_decode(msg, sig, nbits,
 818                              me.mgf, me.hash, me.saltsz, me.rng)
 819
 820 class _tmp:
 821   def encrypt(me, msg, enc):
 822     return me.pubop(enc.encode(msg, me.n.nbits))
 823   def verify(me, msg, sig, enc):
 824     if msg is None: return enc.decode(msg, me.pubop(sig), me.n.nbits)
 825     try:
 826       x = enc.decode(msg, me.pubop(sig), me.n.nbits)
 827       return x is None or x == msg
 828     except ValueError:
 829       return False
 830   def __repr__(me):
 831     return '%s(n = %r, e = %r)' % (_clsname(me), me.n, me.e)
 832   def _repr_pretty_(me, pp, cyclep):
 833     ind = _pp_bgroup_tyname(pp, me)
 834     if cyclep:
 835       pp.text('...')
 836     else:
 837       _pp_kv(pp, 'n', me.n); pp.text(','); pp.breakable()
 838       _pp_kv(pp, 'e', me.e)
 839     pp.end_group(ind, ')')
 840 _augment(RSAPub, _tmp)
 841
 842 class _tmp:
 843   def decrypt(me, ct, enc): return enc.decode(me.privop(ct), me.n.nbits)
 844   def sign(me, msg, enc): return me.privop(enc.encode(msg, me.n.nbits))
 845   def __repr__(me):
 846     return '%s(n = %r, e = %r, d = %s, ' \
 847       'p = %s, q = %s, dp = %s, dq = %s, q_inv = %s)' % \
 848       (_clsname(me), me.n, me.e,
 849        _repr_secret(me.d), _repr_secret(me.p), _repr_secret(me.q),
 850        _repr_secret(me.dp), _repr_secret(me.dq), _repr_secret(me.q_inv))
 851   def _repr_pretty_(me, pp, cyclep):
 852     ind = _pp_bgroup_tyname(pp, me)
 853     if cyclep:
 854       pp.text('...')
 855     else:
 856       _pp_kv(pp, 'n', me.n); pp.text(','); pp.breakable()
 857       _pp_kv(pp, 'e', me.e); pp.text(','); pp.breakable()
 858       _pp_kv(pp, 'd', me.d, secretp = True); pp.text(','); pp.breakable()
 859       _pp_kv(pp, 'p', me.p, secretp = True); pp.text(','); pp.breakable()
 860       _pp_kv(pp, 'q', me.q, secretp = True); pp.text(','); pp.breakable()
 861       _pp_kv(pp, 'dp', me.dp, secretp = True); pp.text(','); pp.breakable()
 862       _pp_kv(pp, 'dq', me.dq, secretp = True); pp.text(','); pp.breakable()
 863       _pp_kv(pp, 'q_inv', me.q_inv, secretp = True)
 864     pp.end_group(ind, ')')
 865 _augment(RSAPriv, _tmp)
 866
 867 ###--------------------------------------------------------------------------
 868 ### DSA and related schemes.
 869
 870 class _tmp:
 871   def __repr__(me): return '%s(G = %r, p = %r, hash = %r)' % \
 872         (_clsname(me), me.G, me.p, me.hash)
 873   def _repr_pretty_(me, pp, cyclep):
 874     ind = _pp_bgroup_tyname(pp, me)
 875     if cyclep:
 876       pp.text('...')
 877     else:
 878       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 879       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 880       _pp_kv(pp, 'hash', me.hash)
 881     pp.end_group(ind, ')')
 882 _augment(DSAPub, _tmp)
 883 _augment(KCDSAPub, _tmp)
 884
 885 class _tmp:
 886   def __repr__(me): return '%s(G = %r, u = %s, p = %r, hash = %r)' % \
 887       (_clsname(me), me.G, _repr_secret(me.u), me.p, me.hash)
 888   def _repr_pretty_(me, pp, cyclep):
 889     ind = _pp_bgroup_tyname(pp, me)
 890     if cyclep:
 891       pp.text('...')
 892     else:
 893       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 894       _pp_kv(pp, 'u', me.u, True); pp.text(','); pp.breakable()
 895       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 896       _pp_kv(pp, 'hash', me.hash)
 897     pp.end_group(ind, ')')
 898 _augment(DSAPriv, _tmp)
 899 _augment(KCDSAPriv, _tmp)
 900
 901 ###--------------------------------------------------------------------------
 902 ### Bernstein's elliptic curve crypto and related schemes.
 903
 904 X25519_BASE = MP(9).storel(32)
 905 X448_BASE = MP(5).storel(56)
 906
 907 Z128 = ByteString.zero(16)
 908
 909 class _BasePub (object):
 910   def __init__(me, pub, *args, **kw):
 911     if not me._PUBSZ.check(len(pub)): raise ValueError('bad public key')
 912     super(_BasePub, me).__init__(*args, **kw)
 913     me.pub = pub
 914   def __repr__(me): return '%s(pub = %r)' % (_clsname(me), me.pub)
 915   def _pp(me, pp): _pp_kv(pp, 'pub', me.pub)
 916   def _repr_pretty_(me, pp, cyclep):
 917     ind = _pp_bgroup_tyname(pp, me)
 918     if cyclep: pp.text('...')
 919     else: me._pp(pp)
 920     pp.end_group(ind, ')')
 921
 922 class _BasePriv (object):
 923   def __init__(me, priv, pub = None, *args, **kw):
 924     if not me._KEYSZ.check(len(priv)): raise ValueError('bad private key')
 925     if pub is None: pub = me._pubkey(priv)
 926     super(_BasePriv, me).__init__(pub = pub, *args, **kw)
 927     me.priv = priv
 928   @classmethod
 929   def generate(cls, rng = rand):
 930     return cls(rng.block(cls._KEYSZ.default))
 931   def __repr__(me):
 932     return '%s(priv = %d, pub = %r)' % \
 933         (_clsname(me), _repr_secret(me.priv), me.pub)
 934   def _pp(me, pp):
 935     _pp_kv(pp, 'priv', me.priv, secretp = True); pp.text(','); pp.breakable()
 936     super(_BasePriv, me)._pp(pp)
 937
 938 class _XDHPub (_BasePub):  pass
 939
 940 class _XDHPriv (_BasePriv):
 941   def _pubkey(me, priv): return me._op(priv, me._BASE)
 942   def agree(me, you): return me._op(me.priv, you.pub)
 943   def boxkey(me, recip): return me._hashkey(me.agree(recip))
 944   def box(me, recip, n, m): return secret_box(me.boxkey(recip), n, m)
 945   def unbox(me, recip, n, c): return secret_unbox(me.boxkey(recip), n, c)
 946
 947 class X25519Pub (_XDHPub):
 948   _PUBSZ = KeySZSet(X25519_PUBSZ)
 949   _BASE = X25519_BASE
 950
 951 class X25519Priv (_XDHPriv, X25519Pub):
 952   _KEYSZ = KeySZSet(X25519_KEYSZ)
 953   def _op(me, k, X): return x25519(k, X)
 954   def _hashkey(me, z): return hsalsa20_prf(z, Z128)
 955
 956 class X448Pub (_XDHPub):
 957   _PUBSZ = KeySZSet(X448_PUBSZ)
 958   _BASE = X448_BASE
 959
 960 class X448Priv (_XDHPriv, X448Pub):
 961   _KEYSZ = KeySZSet(X448_KEYSZ)
 962   def _op(me, k, X): return x448(k, X)
 963   def _hashkey(me, z): return Shake256().hash(z).done(salsa20.keysz.default)
 964
 965 class _EdDSAPub (_BasePub):
 966   def beginhash(me): return me._HASH()
 967   def endhash(me, h): return h.done()
 968
 969 class _EdDSAPriv (_BasePriv, _EdDSAPub):
 970   pass
 971
 972 class Ed25519Pub (_EdDSAPub):
 973   _PUBSZ = KeySZSet(ED25519_PUBSZ)
 974   _HASH = sha512
 975   def verify(me, msg, sig, **kw):
 976     return ed25519_verify(me.pub, msg, sig, **kw)
 977
 978 class Ed25519Priv (_EdDSAPriv, Ed25519Pub):
 979   _KEYSZ = KeySZAny(ED25519_KEYSZ)
 980   def _pubkey(me, priv): return ed25519_pubkey(priv)
 981   def sign(me, msg, **kw):
 982     return ed25519_sign(me.priv, msg, pub = me.pub, **kw)
 983
 984 class Ed448Pub (_EdDSAPub):
 985   _PUBSZ = KeySZSet(ED448_PUBSZ)
 986   _HASH = shake256
 987   def verify(me, msg, sig, **kw):
 988     return ed448_verify(me.pub, msg, sig, **kw)
 989
 990 class Ed448Priv (_EdDSAPriv, Ed448Pub):
 991   _KEYSZ = KeySZAny(ED448_KEYSZ)
 992   def _pubkey(me, priv): return ed448_pubkey(priv)
 993   def sign(me, msg, **kw):
 994     return ed448_sign(me.priv, msg, pub = me.pub, **kw)
 995
 996 ###--------------------------------------------------------------------------
 997 ### Built-in algorithm and group tables.
 998
 999 class _tmp:
1000   def __repr__(me):
1001     return '{%s}' % ', '.join(['%r: %r' % kv for kv in _iteritems(me)])
1002   def _repr_pretty_(me, pp, cyclep):
1003     ind = _pp_bgroup(pp, '{ ')
1004     if cyclep: pp.text('...')
1005     else: _pp_dict(pp, _iteritems(me))
1006     pp.end_group(ind, ' }')
1007 _augment(_base._MiscTable, _tmp)
1008
1009 ###--------------------------------------------------------------------------
1010 ### Prime number generation.
1011
1012 class PrimeGenEventHandler (object):
1013   def pg_begin(me, ev):
1014     return me.pg_try(ev)
1015   def pg_done(me, ev):
1016     return PGEN_DONE
1017   def pg_abort(me, ev):
1018     return PGEN_TRY
1019   def pg_fail(me, ev):
1020     return PGEN_TRY
1021   def pg_pass(me, ev):
1022     return PGEN_TRY
1023
1024 class SophieGermainStepJump (object):
1025   def pg_begin(me, ev):
1026     me.lf = PrimeFilter(ev.x)
1027     me.hf = me.lf.muladd(2, 1)
1028     return me.cont(ev)
1029   def pg_try(me, ev):
1030     me.step()
1031     return me.cont(ev)
1032   def cont(me, ev):
1033     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
1034       me.step()
1035     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
1036       return PGEN_ABORT
1037     ev.x = me.lf.x
1038     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
1039       return PGEN_DONE
1040     return PGEN_TRY
1041   def pg_done(me, ev):
1042     del me.lf
1043     del me.hf
1044
1045 class SophieGermainStepper (SophieGermainStepJump):
1046   def __init__(me, step):
1047     me.lstep = step;
1048     me.hstep = 2 * step
1049   def step(me):
1050     me.lf.step(me.lstep)
1051     me.hf.step(me.hstep)
1052
1053 class SophieGermainJumper (SophieGermainStepJump):
1054   def __init__(me, jump):
1055     me.ljump = PrimeFilter(jump);
1056     me.hjump = me.ljump.muladd(2, 0)
1057   def step(me):
1058     me.lf.jump(me.ljump)
1059     me.hf.jump(me.hjump)
1060   def pg_done(me, ev):
1061     del me.ljump
1062     del me.hjump
1063     SophieGermainStepJump.pg_done(me, ev)
1064
1065 class SophieGermainTester (object):
1066   def __init__(me):
1067     pass
1068   def pg_begin(me, ev):
1069     me.lr = RabinMiller(ev.x)
1070     me.hr = RabinMiller(2 * ev.x + 1)
1071   def pg_try(me, ev):
1072     lst = me.lr.test(ev.rng.range(me.lr.x))
1073     if lst != PGEN_PASS and lst != PGEN_DONE:
1074       return lst
1075     rst = me.hr.test(ev.rng.range(me.hr.x))
1076     if rst != PGEN_PASS and rst != PGEN_DONE:
1077       return rst
1078     if lst == PGEN_DONE and rst == PGEN_DONE:
1079       return PGEN_DONE
1080     return PGEN_PASS
1081   def pg_done(me, ev):
1082     del me.lr
1083     del me.hr
1084
1085 class PrimitiveStepper (PrimeGenEventHandler):
1086   def __init__(me):
1087     pass
1088   def pg_try(me, ev):
1089     ev.x = me.i.next()
1090     return PGEN_TRY
1091   def pg_begin(me, ev):
1092     me.i = iter(smallprimes)
1093     return me.pg_try(ev)
1094
1095 class PrimitiveTester (PrimeGenEventHandler):
1096   def __init__(me, mod, hh = [], exp = None):
1097     me.mod = MPMont(mod)
1098     me.exp = exp
1099     me.hh = hh
1100   def pg_try(me, ev):
1101     x = ev.x
1102     if me.exp is not None:
1103       x = me.mod.exp(x, me.exp)
1104       if x == 1: return PGEN_FAIL
1105     for h in me.hh:
1106       if me.mod.exp(x, h) == 1: return PGEN_FAIL
1107     ev.x = x
1108     return PGEN_DONE
1109
1110 class SimulStepper (PrimeGenEventHandler):
1111   def __init__(me, mul = 2, add = 1, step = 2):
1112     me.step = step
1113     me.mul = mul
1114     me.add = add
1115   def _stepfn(me, step):
1116     if step <= 0:
1117       raise ValueError('step must be positive')
1118     if step <= MPW_MAX:
1119       return lambda f: f.step(step)
1120     j = PrimeFilter(step)
1121     return lambda f: f.jump(j)
1122   def pg_begin(me, ev):
1123     x = ev.x
1124     me.lf = PrimeFilter(x)
1125     me.hf = PrimeFilter(x * me.mul + me.add)
1126     me.lstep = me._stepfn(me.step)
1127     me.hstep = me._stepfn(me.step * me.mul)
1128     SimulStepper._cont(me, ev)
1129   def pg_try(me, ev):
1130     me._step()
1131     me._cont(ev)
1132   def _step(me):
1133     me.lstep(me.lf)
1134     me.hstep(me.hf)
1135   def _cont(me, ev):
1136     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
1137       me._step()
1138     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
1139       return PGEN_ABORT
1140     ev.x = me.lf.x
1141     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
1142       return PGEN_DONE
1143     return PGEN_TRY
1144   def pg_done(me, ev):
1145     del me.lf
1146     del me.hf
1147     del me.lstep
1148     del me.hstep
1149
1150 class SimulTester (PrimeGenEventHandler):
1151   def __init__(me, mul = 2, add = 1):
1152     me.mul = mul
1153     me.add = add
1154   def pg_begin(me, ev):
1155     x = ev.x
1156     me.lr = RabinMiller(x)
1157     me.hr = RabinMiller(x * me.mul + me.add)
1158   def pg_try(me, ev):
1159     lst = me.lr.test(ev.rng.range(me.lr.x))
1160     if lst != PGEN_PASS and lst != PGEN_DONE:
1161       return lst
1162     rst = me.hr.test(ev.rng.range(me.hr.x))
1163     if rst != PGEN_PASS and rst != PGEN_DONE:
1164       return rst
1165     if lst == PGEN_DONE and rst == PGEN_DONE:
1166       return PGEN_DONE
1167     return PGEN_PASS
1168   def pg_done(me, ev):
1169     del me.lr
1170     del me.hr
1171
1172 def sgprime(start, step = 2, name = 'p', event = pgen_nullev, nsteps = 0):
1173   start = MP(start)
1174   return pgen(start, name, SimulStepper(step = step), SimulTester(), event,
1175               nsteps, RabinMiller.iters(start.nbits))
1176
1177 def findprimitive(mod, hh = [], exp = None, name = 'g', event = pgen_nullev):
1178   return pgen(0, name, PrimitiveStepper(), PrimitiveTester(mod, hh, exp),
1179               event, 0, 1)
1180
1181 def kcdsaprime(pbits, qbits, rng = rand,
1182                event = pgen_nullev, name = 'p', nsteps = 0):
1183   hbits = pbits - qbits
1184   h = pgen(rng.mp(hbits, 1), name + ' [h]',
1185            PrimeGenStepper(2), PrimeGenTester(),
1186            event, nsteps, RabinMiller.iters(hbits))
1187   q = pgen(rng.mp(qbits, 1), name, SimulStepper(2 * h, 1, 2),
1188            SimulTester(2 * h, 1), event, nsteps, RabinMiller.iters(qbits))
1189   p = 2 * q * h + 1
1190   return p, q, h
1191
1192 #----- That's all, folks ----------------------------------------------------