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 import _base
  27 import types as _types
  28 from binascii import hexlify as _hexify, unhexlify as _unhexify
  29 from sys import argv as _argv
  30
  31 ###--------------------------------------------------------------------------
  32 ### Basic stuff.
  33
  34 ## For the benefit of the default keyreporter, we need the program na,e.
  35 _base._ego(_argv[0])
  36
  37 ## Initialize the module.  Drag in the static methods of the various
  38 ## classes; create names for the various known crypto algorithms.
  39 def _init():
  40   d = globals()
  41   b = _base.__dict__;
  42   for i in b:
  43     if i[0] != '_':
  44       d[i] = b[i];
  45   for i in ['MP', 'GF', 'Field',
  46             'ECPt', 'ECPtCurve', 'ECCurve', 'ECInfo',
  47             'DHInfo', 'BinDHInfo', 'RSAPriv', 'BBSPriv',
  48             'PrimeFilter', 'RabinMiller',
  49             'Group', 'GE',
  50             'KeySZ', 'KeyData']:
  51     c = d[i]
  52     pre = '_' + i + '_'
  53     plen = len(pre)
  54     for j in b:
  55       if j[:plen] == pre:
  56         setattr(c, j[plen:], classmethod(b[j]))
  57   for i in [gcciphers, gchashes, gcmacs, gcprps]:
  58     for c in i.itervalues():
  59       d[c.name.replace('-', '_').translate(None, '/')] = c
  60   for c in gccrands.itervalues():
  61     d[c.name.replace('-', '_').translate(None, '/') + 'rand'] = c
  62 _init()
  63
  64 ## A handy function for our work: add the methods of a named class to an
  65 ## existing class.  This is how we write the Python-implemented parts of our
  66 ## mostly-C types.
  67 def _augment(c, cc):
  68   for i in cc.__dict__:
  69     a = cc.__dict__[i]
  70     if type(a) is _types.MethodType:
  71       a = a.im_func
  72     elif type(a) not in (_types.FunctionType, staticmethod, classmethod):
  73       continue
  74     setattr(c, i, a)
  75
  76 ## Parsing functions tend to return the object parsed and the remainder of
  77 ## the input.  This checks that the remainder is input and, if so, returns
  78 ## just the object.
  79 def _checkend(r):
  80   x, rest = r
  81   if rest != '':
  82     raise SyntaxError, 'junk at end of string'
  83   return x
  84
  85 ## Some pretty-printing utilities.
  86 def _clsname(me): return type(me).__name__
  87 def _pp_str(me, pp, cyclep): pp.text(cyclep and '...' or str(me))
  88 def _pp_bgroup(pp, text):
  89   ind = len(text)
  90   pp.begin_group(ind, text)
  91   return ind
  92 def _pp_bgroup_tyname(pp, obj, open = '('):
  93   return _pp_bgroup(pp, _clsname(obj) + open)
  94 def _pp_kv(pp, k, v):
  95   ind = _pp_bgroup(pp, k + ' = ')
  96   pp.pretty(v)
  97   pp.end_group(ind, '')
  98 def _pp_commas(pp, printfn, items):
  99   firstp = True
 100   for i in items:
 101     if firstp: firstp = False
 102     else: pp.text(','); pp.breakable()
 103     printfn(i)
 104 def _pp_dict(pp, items):
 105   def p((k, v)):
 106     pp.begin_group(0)
 107     pp.pretty(k)
 108     pp.text(':')
 109     pp.begin_group(2)
 110     pp.breakable()
 111     pp.pretty(v)
 112     pp.end_group(2)
 113     pp.end_group(0)
 114   _pp_commas(pp, p, items)
 115
 116 ###--------------------------------------------------------------------------
 117 ### Bytestrings.
 118
 119 class _tmp:
 120   def fromhex(x):
 121     return ByteString(_unhexify(x))
 122   fromhex = staticmethod(fromhex)
 123   def __hex__(me):
 124     return _hexify(me)
 125   def __repr__(me):
 126     return 'bytes(%r)' % hex(me)
 127 _augment(ByteString, _tmp)
 128 ByteString.__hash__ = str.__hash__
 129 bytes = ByteString.fromhex
 130
 131 ###--------------------------------------------------------------------------
 132 ### Hashing.
 133
 134 class _tmp:
 135   def check(me, h):
 136     hh = me.done()
 137     return ctstreq(h, hh)
 138 _augment(GHash, _tmp)
 139 _augment(Poly1305Hash, _tmp)
 140
 141 ###--------------------------------------------------------------------------
 142 ### NaCl `secretbox'.
 143
 144 def secret_box(k, n, m):
 145   E = xsalsa20(k).setiv(n)
 146   r = E.enczero(poly1305.keysz.default)
 147   s = E.enczero(poly1305.masksz)
 148   y = E.encrypt(m)
 149   t = poly1305(r)(s).hash(y).done()
 150   return ByteString(t + y)
 151
 152 def secret_unbox(k, n, c):
 153   E = xsalsa20(k).setiv(n)
 154   r = E.enczero(poly1305.keysz.default)
 155   s = E.enczero(poly1305.masksz)
 156   y = c[poly1305.tagsz:]
 157   if not poly1305(r)(s).hash(y).check(c[0:poly1305.tagsz]):
 158     raise ValueError, 'decryption failed'
 159   return E.decrypt(c[poly1305.tagsz:])
 160
 161 ###--------------------------------------------------------------------------
 162 ### Multiprecision integers and binary polynomials.
 163
 164 def _split_rat(x):
 165   if isinstance(x, BaseRat): return x._n, x._d
 166   else: return x, 1
 167 class BaseRat (object):
 168   """Base class implementing fields of fractions over Euclidean domains."""
 169   def __new__(cls, a, b):
 170     a, b = cls.RING(a), cls.RING(b)
 171     q, r = divmod(a, b)
 172     if r == 0: return q
 173     g = b.gcd(r)
 174     me = super(BaseRat, cls).__new__(cls)
 175     me._n = a//g
 176     me._d = b//g
 177     return me
 178   @property
 179   def numer(me): return me._n
 180   @property
 181   def denom(me): return me._d
 182   def __str__(me): return '%s/%s' % (me._n, me._d)
 183   def __repr__(me): return '%s(%s, %s)' % (_clsname(me), me._n, me._d)
 184   _repr_pretty_ = _pp_str
 185
 186   def __add__(me, you):
 187     n, d = _split_rat(you)
 188     return type(me)(me._n*d + n*me._d, d*me._d)
 189   __radd__ = __add__
 190   def __sub__(me, you):
 191     n, d = _split_rat(you)
 192     return type(me)(me._n*d - n*me._d, d*me._d)
 193   def __rsub__(me, you):
 194     n, d = _split_rat(you)
 195     return type(me)(n*me._d - me._n*d, d*me._d)
 196   def __mul__(me, you):
 197     n, d = _split_rat(you)
 198     return type(me)(me._n*n, me._d*d)
 199   def __div__(me, you):
 200     n, d = _split_rat(you)
 201     return type(me)(me._n*d, me._d*n)
 202   def __rdiv__(me, you):
 203     n, d = _split_rat(you)
 204     return type(me)(me._d*n, me._n*d)
 205   def __cmp__(me, you):
 206     n, d = _split_rat(you)
 207     return type(me)(me._n*d, n*me._d)
 208   def __rcmp__(me, you):
 209     n, d = _split_rat(you)
 210     return cmp(n*me._d, me._n*d)
 211
 212 class IntRat (BaseRat):
 213   RING = MP
 214
 215 class GFRat (BaseRat):
 216   RING = GF
 217
 218 class _tmp:
 219   def negp(x): return x < 0
 220   def posp(x): return x > 0
 221   def zerop(x): return x == 0
 222   def oddp(x): return x.testbit(0)
 223   def evenp(x): return not x.testbit(0)
 224   def mont(x): return MPMont(x)
 225   def barrett(x): return MPBarrett(x)
 226   def reduce(x): return MPReduce(x)
 227   def __div__(me, you): return IntRat(me, you)
 228   def __rdiv__(me, you): return IntRat(you, me)
 229   _repr_pretty_ = _pp_str
 230 _augment(MP, _tmp)
 231
 232 class _tmp:
 233   def zerop(x): return x == 0
 234   def reduce(x): return GFReduce(x)
 235   def trace(x, y): return x.reduce().trace(y)
 236   def halftrace(x, y): return x.reduce().halftrace(y)
 237   def modsqrt(x, y): return x.reduce().sqrt(y)
 238   def quadsolve(x, y): return x.reduce().quadsolve(y)
 239   def __div__(me, you): return GFRat(me, you)
 240   def __rdiv__(me, you): return GFRat(you, me)
 241   _repr_pretty_ = _pp_str
 242 _augment(GF, _tmp)
 243
 244 class _tmp:
 245   def product(*arg):
 246     'product(ITERABLE) or product(I, ...) -> PRODUCT'
 247     return MPMul(*arg).done()
 248   product = staticmethod(product)
 249 _augment(MPMul, _tmp)
 250
 251 ###--------------------------------------------------------------------------
 252 ### Abstract fields.
 253
 254 class _tmp:
 255   def fromstring(str): return _checkend(Field.parse(str))
 256   fromstring = staticmethod(fromstring)
 257 _augment(Field, _tmp)
 258
 259 class _tmp:
 260   def __repr__(me): return '%s(%sL)' % (_clsname(me), me.p)
 261   def __hash__(me): return 0x114401de ^ hash(me.p)
 262   def _repr_pretty_(me, pp, cyclep):
 263     ind = _pp_bgroup_tyname(pp, me)
 264     if cyclep: pp.text('...')
 265     else: pp.pretty(me.p)
 266     pp.end_group(ind, ')')
 267   def ec(me, a, b): return ECPrimeProjCurve(me, a, b)
 268 _augment(PrimeField, _tmp)
 269
 270 class _tmp:
 271   def __repr__(me): return '%s(%#xL)' % (_clsname(me), me.p)
 272   def ec(me, a, b): return ECBinProjCurve(me, a, b)
 273   def _repr_pretty_(me, pp, cyclep):
 274     ind = _pp_bgroup_tyname(pp, me)
 275     if cyclep: pp.text('...')
 276     else: pp.text('%#x' % me.p)
 277     pp.end_group(ind, ')')
 278 _augment(BinField, _tmp)
 279
 280 class _tmp:
 281   def __hash__(me): return 0x23e4701c ^ hash(me.p)
 282 _augment(BinPolyField, _tmp)
 283
 284 class _tmp:
 285   def __hash__(me):
 286     h = 0x9a7d6240
 287     h ^=   hash(me.p)
 288     h ^= 2*hash(me.beta) & 0xffffffff
 289     return h
 290 _augment(BinNormField, _tmp)
 291
 292 class _tmp:
 293   def __str__(me): return str(me.value)
 294   def __repr__(me): return '%s(%s)' % (repr(me.field), repr(me.value))
 295   _repr_pretty_ = _pp_str
 296 _augment(FE, _tmp)
 297
 298 ###--------------------------------------------------------------------------
 299 ### Elliptic curves.
 300
 301 class _tmp:
 302   def __repr__(me):
 303     return '%s(%r, %s, %s)' % (_clsname(me), me.field, me.a, me.b)
 304   def _repr_pretty_(me, pp, cyclep):
 305     ind = _pp_bgroup_tyname(pp, me)
 306     if cyclep:
 307       pp.text('...')
 308     else:
 309       pp.pretty(me.field); pp.text(','); pp.breakable()
 310       pp.pretty(me.a); pp.text(','); pp.breakable()
 311       pp.pretty(me.b)
 312     pp.end_group(ind, ')')
 313   def frombuf(me, s):
 314     return ecpt.frombuf(me, s)
 315   def fromraw(me, s):
 316     return ecpt.fromraw(me, s)
 317   def pt(me, *args):
 318     return me(*args)
 319 _augment(ECCurve, _tmp)
 320
 321 class _tmp:
 322   def __hash__(me):
 323     h = 0x6751d341
 324     h ^=   hash(me.field)
 325     h ^= 2*hash(me.a) ^ 0xffffffff
 326     h ^= 5*hash(me.b) ^ 0xffffffff
 327     return h
 328 _augment(ECPrimeCurve, _tmp)
 329
 330 class _tmp:
 331   def __hash__(me):
 332     h = 0x2ac203c5
 333     h ^=   hash(me.field)
 334     h ^= 2*hash(me.a) ^ 0xffffffff
 335     h ^= 5*hash(me.b) ^ 0xffffffff
 336     return h
 337 _augment(ECBinCurve, _tmp)
 338
 339 class _tmp:
 340   def __repr__(me):
 341     if not me: return '%s()' % _clsname(me)
 342     return '%s(%s, %s)' % (_clsname(me), me.ix, me.iy)
 343   def __str__(me):
 344     if not me: return 'inf'
 345     return '(%s, %s)' % (me.ix, me.iy)
 346   def _repr_pretty_(me, pp, cyclep):
 347     if cyclep:
 348       pp.text('...')
 349     elif not me:
 350       pp.text('inf')
 351     else:
 352       ind = _pp_bgroup(pp, '(')
 353       pp.pretty(me.ix); pp.text(','); pp.breakable()
 354       pp.pretty(me.iy)
 355       pp.end_group(ind, ')')
 356 _augment(ECPt, _tmp)
 357
 358 class _tmp:
 359   def __repr__(me):
 360     return '%s(curve = %r, G = %r, r = %s, h = %s)' % \
 361            (_clsname(me), me.curve, me.G, me.r, me.h)
 362   def _repr_pretty_(me, pp, cyclep):
 363     ind = _pp_bgroup_tyname(pp, me)
 364     if cyclep:
 365       pp.text('...')
 366     else:
 367       _pp_kv(pp, 'curve', me.curve); pp.text(','); pp.breakable()
 368       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 369       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 370       _pp_kv(pp, 'h', me.h)
 371     pp.end_group(ind, ')')
 372   def __hash__(me):
 373     h = 0x9bedb8de
 374     h ^=   hash(me.curve)
 375     h ^= 2*hash(me.G) & 0xffffffff
 376     return h
 377   def group(me):
 378     return ECGroup(me)
 379 _augment(ECInfo, _tmp)
 380
 381 class _tmp:
 382   def __repr__(me):
 383     if not me: return '%r()' % (me.curve)
 384     return '%r(%s, %s)' % (me.curve, me.x, me.y)
 385   def __str__(me):
 386     if not me: return 'inf'
 387     return '(%s, %s)' % (me.x, me.y)
 388   def _repr_pretty_(me, pp, cyclep):
 389     if cyclep:
 390       pp.text('...')
 391     elif not me:
 392       pp.text('inf')
 393     else:
 394       ind = _pp_bgroup(pp, '(')
 395       pp.pretty(me.x); pp.text(','); pp.breakable()
 396       pp.pretty(me.y)
 397       pp.end_group(ind, ')')
 398 _augment(ECPtCurve, _tmp)
 399
 400 ###--------------------------------------------------------------------------
 401 ### Key sizes.
 402
 403 class _tmp:
 404   def __repr__(me): return '%s(%d)' % (_clsname(me), me.default)
 405   def check(me, sz): return True
 406   def best(me, sz): return sz
 407 _augment(KeySZAny, _tmp)
 408
 409 class _tmp:
 410   def __repr__(me):
 411     return '%s(%d, %d, %d, %d)' % \
 412            (_clsname(me), me.default, me.min, me.max, me.mod)
 413   def _repr_pretty_(me, pp, cyclep):
 414     ind = _pp_bgroup_tyname(pp, me)
 415     if cyclep:
 416       pp.text('...')
 417     else:
 418       pp.pretty(me.default); pp.text(','); pp.breakable()
 419       pp.pretty(me.min); pp.text(','); pp.breakable()
 420       pp.pretty(me.max); pp.text(','); pp.breakable()
 421       pp.pretty(me.mod)
 422     pp.end_group(ind, ')')
 423   def check(me, sz): return me.min <= sz <= me.max and sz % me.mod == 0
 424   def best(me, sz):
 425     if sz < me.min: raise ValueError, 'key too small'
 426     elif sz > me.max: return me.max
 427     else: return sz - (sz % me.mod)
 428 _augment(KeySZRange, _tmp)
 429
 430 class _tmp:
 431   def __repr__(me): return '%s(%d, %s)' % (_clsname(me), me.default, me.set)
 432   def _repr_pretty_(me, pp, cyclep):
 433     ind = _pp_bgroup_tyname(pp, me)
 434     if cyclep:
 435       pp.text('...')
 436     else:
 437       pp.pretty(me.default); pp.text(','); pp.breakable()
 438       ind1 = _pp_bgroup(pp, '{')
 439       _pp_commas(pp, pp.pretty, me.set)
 440       pp.end_group(ind1, '}')
 441     pp.end_group(ind, ')')
 442   def check(me, sz): return sz in me.set
 443   def best(me, sz):
 444     found = -1
 445     for i in me.set:
 446       if found < i <= sz: found = i
 447     if found < 0: raise ValueError, 'key too small'
 448     return found
 449 _augment(KeySZSet, _tmp)
 450
 451 ###--------------------------------------------------------------------------
 452 ### Key data objects.
 453
 454 class _tmp:
 455   def __repr__(me): return '%s(%r)' % (_clsname(me), me.name)
 456 _augment(KeyFile, _tmp)
 457
 458 class _tmp:
 459   def __repr__(me): return '%s(%r)' % (_clsname(me), me.fulltag)
 460 _augment(Key, _tmp)
 461
 462 class _tmp:
 463   def __repr__(me):
 464     return '%s({%s})' % (_clsname(me),
 465                          ', '.join(['%r: %r' % kv for kv in me.iteritems()]))
 466   def _repr_pretty_(me, pp, cyclep):
 467     ind = _pp_bgroup_tyname(pp, me)
 468     if cyclep: pp.text('...')
 469     else: _pp_dict(pp, me.iteritems())
 470     pp.end_group(ind, ')')
 471 _augment(KeyAttributes, _tmp)
 472
 473 class _tmp:
 474   def __repr__(me):
 475     return '%s(%s, %r)' % \
 476         (_clsname(me), repr(me._guts()), me.writeflags(me.flags))
 477   def _repr_pretty_(me, pp, cyclep):
 478     ind = _pp_bgroup_tyname(pp, me)
 479     if cyclep:
 480       pp.text('...')
 481     else:
 482       pp.pretty(me.guts()); pp.text(','); pp.breakable()
 483       pp.pretty(me.writeflags(me.flags))
 484     pp.end_group(ind, ')')
 485 _augment(KeyData, _tmp)
 486
 487 class _tmp:
 488   def _guts(me): return me.bin
 489 _augment(KeyDataBinary, _tmp)
 490
 491 class _tmp:
 492   def _guts(me): return me.ct
 493 _augment(KeyDataEncrypted, _tmp)
 494
 495 class _tmp:
 496   def _guts(me): return me.mp
 497 _augment(KeyDataMP, _tmp)
 498
 499 class _tmp:
 500   def _guts(me): return me.str
 501 _augment(KeyDataString, _tmp)
 502
 503 class _tmp:
 504   def _guts(me): return me.ecpt
 505 _augment(KeyDataECPt, _tmp)
 506
 507 class _tmp:
 508   def __repr__(me):
 509     return '%s({%s})' % (_clsname(me),
 510                          ', '.join(['%r: %r' % kv for kv in me.iteritems()]))
 511   def _repr_pretty_(me, pp, cyclep):
 512     ind = _pp_bgroup_tyname(pp, me, '({ ')
 513     if cyclep: pp.text('...')
 514     else: _pp_dict(pp, me.iteritems())
 515     pp.end_group(ind, ' })')
 516 _augment(KeyDataStructured, _tmp)
 517
 518 ###--------------------------------------------------------------------------
 519 ### Abstract groups.
 520
 521 class _tmp:
 522   def __repr__(me):
 523     return '%s(p = %s, r = %s, g = %s)' % (_clsname(me), me.p, me.r, me.g)
 524   def _repr_pretty_(me, pp, cyclep):
 525     ind = _pp_bgroup_tyname(pp, me)
 526     if cyclep:
 527       pp.text('...')
 528     else:
 529       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 530       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 531       _pp_kv(pp, 'g', me.g)
 532     pp.end_group(ind, ')')
 533 _augment(FGInfo, _tmp)
 534
 535 class _tmp:
 536   def group(me): return PrimeGroup(me)
 537 _augment(DHInfo, _tmp)
 538
 539 class _tmp:
 540   def group(me): return BinGroup(me)
 541 _augment(BinDHInfo, _tmp)
 542
 543 class _tmp:
 544   def __repr__(me):
 545     return '%s(%r)' % (_clsname(me), me.info)
 546   def _repr_pretty_(me, pp, cyclep):
 547     ind = _pp_bgroup_tyname(pp, me)
 548     if cyclep: pp.text('...')
 549     else: pp.pretty(me.info)
 550     pp.end_group(ind, ')')
 551 _augment(Group, _tmp)
 552
 553 class _tmp:
 554   def __hash__(me):
 555     info = me.info
 556     h = 0xbce3cfe6
 557     h ^=   hash(info.p)
 558     h ^= 2*hash(info.r) & 0xffffffff
 559     h ^= 5*hash(info.g) & 0xffffffff
 560     return h
 561   def _get_geval(me, x): return MP(x)
 562 _augment(PrimeGroup, _tmp)
 563
 564 class _tmp:
 565   def __hash__(me):
 566     info = me.info
 567     h = 0x80695949
 568     h ^=   hash(info.p)
 569     h ^= 2*hash(info.r) & 0xffffffff
 570     h ^= 5*hash(info.g) & 0xffffffff
 571     return h
 572   def _get_geval(me, x): return GF(x)
 573 _augment(BinGroup, _tmp)
 574
 575 class _tmp:
 576   def __hash__(me): return 0x0ec23dab ^ hash(me.info)
 577   def _get_geval(me, x): return x.toec()
 578 _augment(ECGroup, _tmp)
 579
 580 class _tmp:
 581   def __repr__(me):
 582     return '%r(%r)' % (me.group, str(me))
 583   def _repr_pretty_(me, pp, cyclep):
 584     pp.pretty(type(me)._get_geval(me))
 585 _augment(GE, _tmp)
 586
 587 ###--------------------------------------------------------------------------
 588 ### RSA encoding techniques.
 589
 590 class PKCS1Crypt (object):
 591   def __init__(me, ep = '', rng = rand):
 592     me.ep = ep
 593     me.rng = rng
 594   def encode(me, msg, nbits):
 595     return _base._p1crypt_encode(msg, nbits, me.ep, me.rng)
 596   def decode(me, ct, nbits):
 597     return _base._p1crypt_decode(ct, nbits, me.ep, me.rng)
 598
 599 class PKCS1Sig (object):
 600   def __init__(me, ep = '', rng = rand):
 601     me.ep = ep
 602     me.rng = rng
 603   def encode(me, msg, nbits):
 604     return _base._p1sig_encode(msg, nbits, me.ep, me.rng)
 605   def decode(me, msg, sig, nbits):
 606     return _base._p1sig_decode(msg, sig, nbits, me.ep, me.rng)
 607
 608 class OAEP (object):
 609   def __init__(me, mgf = sha_mgf, hash = sha, ep = '', rng = rand):
 610     me.mgf = mgf
 611     me.hash = hash
 612     me.ep = ep
 613     me.rng = rng
 614   def encode(me, msg, nbits):
 615     return _base._oaep_encode(msg, nbits, me.mgf, me.hash, me.ep, me.rng)
 616   def decode(me, ct, nbits):
 617     return _base._oaep_decode(ct, nbits, me.mgf, me.hash, me.ep, me.rng)
 618
 619 class PSS (object):
 620   def __init__(me, mgf = sha_mgf, hash = sha, saltsz = None, rng = rand):
 621     me.mgf = mgf
 622     me.hash = hash
 623     if saltsz is None:
 624       saltsz = hash.hashsz
 625     me.saltsz = saltsz
 626     me.rng = rng
 627   def encode(me, msg, nbits):
 628     return _base._pss_encode(msg, nbits, me.mgf, me.hash, me.saltsz, me.rng)
 629   def decode(me, msg, sig, nbits):
 630     return _base._pss_decode(msg, sig, nbits,
 631                              me.mgf, me.hash, me.saltsz, me.rng)
 632
 633 class _tmp:
 634   def encrypt(me, msg, enc):
 635     return me.pubop(enc.encode(msg, me.n.nbits))
 636   def verify(me, msg, sig, enc):
 637     if msg is None: return enc.decode(msg, me.pubop(sig), me.n.nbits)
 638     try:
 639       x = enc.decode(msg, me.pubop(sig), me.n.nbits)
 640       return x is None or x == msg
 641     except ValueError:
 642       return False
 643 _augment(RSAPub, _tmp)
 644
 645 class _tmp:
 646   def decrypt(me, ct, enc): return enc.decode(me.privop(ct), me.n.nbits)
 647   def sign(me, msg, enc): return me.privop(enc.encode(msg, me.n.nbits))
 648 _augment(RSAPriv, _tmp)
 649
 650 ###--------------------------------------------------------------------------
 651 ### Bernstein's elliptic curve crypto and related schemes.
 652
 653 X25519_BASE = \
 654   bytes('0900000000000000000000000000000000000000000000000000000000000000')
 655
 656 X448_BASE = \
 657   bytes('05000000000000000000000000000000000000000000000000000000'
 658         '00000000000000000000000000000000000000000000000000000000')
 659
 660 Z128 = bytes('00000000000000000000000000000000')
 661
 662 class _BoxyPub (object):
 663   def __init__(me, pub, *kw, **kwargs):
 664     if len(pub) != me._PUBSZ: raise ValueError, 'bad public key'
 665     super(_BoxyPub, me).__init__(*kw, **kwargs)
 666     me.pub = pub
 667
 668 class _BoxyPriv (_BoxyPub):
 669   def __init__(me, priv, pub = None, *kw, **kwargs):
 670     if len(priv) != me._KEYSZ: raise ValueError, 'bad private key'
 671     if pub is None: pub = me._op(priv, me._BASE)
 672     super(_BoxyPriv, me).__init__(pub = pub, *kw, **kwargs)
 673     me.priv = priv
 674   def agree(me, you): return me._op(me.priv, you.pub)
 675   def boxkey(me, recip):
 676     return me._hashkey(me.agree(recip))
 677   def box(me, recip, n, m):
 678     return secret_box(me.boxkey(recip), n, m)
 679   def unbox(me, recip, n, c):
 680     return secret_unbox(me.boxkey(recip, n, c))
 681
 682 class X25519Pub (_BoxyPub):
 683   _PUBSZ = X25519_PUBSZ
 684   _BASE = X25519_BASE
 685
 686 class X25519Priv (_BoxyPriv, X25519Pub):
 687   _KEYSZ = X25519_KEYSZ
 688   def _op(me, k, X): return x25519(k, X)
 689   def _hashkey(me, z): return hsalsa20_prf(z, Z128)
 690
 691 class X448Pub (_BoxyPub):
 692   _PUBSZ = X448_PUBSZ
 693   _BASE = X448_BASE
 694
 695 class X448Priv (_BoxyPriv, X448Pub):
 696   _KEYSZ = X448_KEYSZ
 697   def _op(me, k, X): return x448(k, X)
 698   ##def _hashkey(me, z): return ???
 699
 700 class Ed25519Pub (object):
 701   def __init__(me, pub):
 702     me.pub = pub
 703   def verify(me, msg, sig):
 704     return ed25519_verify(me.pub, msg, sig)
 705
 706 class Ed25519Priv (Ed25519Pub):
 707   def __init__(me, priv):
 708     me.priv = priv
 709     Ed25519Pub.__init__(me, ed25519_pubkey(priv))
 710   def sign(me, msg):
 711     return ed25519_sign(me.priv, msg, pub = me.pub)
 712   @classmethod
 713   def generate(cls, rng = rand):
 714     return cls(rng.block(ED25519_KEYSZ))
 715
 716 ###--------------------------------------------------------------------------
 717 ### Built-in named curves and prime groups.
 718
 719 class _groupmap (object):
 720   def __init__(me, map, nth):
 721     me.map = map
 722     me.nth = nth
 723     me._n = max(map.values()) + 1
 724     me.i = me._n*[None]
 725   def __repr__(me):
 726     return '{%s}' % ', '.join(['%r: %r' % kv for kv in me.iteritems()])
 727   def _repr_pretty_(me, pp, cyclep):
 728     ind = _pp_bgroup(pp, '{ ')
 729     if cyclep: pp.text('...')
 730     else: _pp_dict(pp, me.iteritems())
 731     pp.end_group(ind, ' }')
 732   def __len__(me):
 733     return me._n
 734   def __contains__(me, k):
 735     return k in me.map
 736   def __getitem__(me, k):
 737     i = me.map[k]
 738     if me.i[i] is None:
 739       me.i[i] = me.nth(i)
 740     return me.i[i]
 741   def __setitem__(me, k, v):
 742     raise TypeError, "immutable object"
 743   def __iter__(me):
 744     return iter(me.map)
 745   def iterkeys(me):
 746     return iter(me.map)
 747   def itervalues(me):
 748     for k in me:
 749       yield me[k]
 750   def iteritems(me):
 751     for k in me:
 752       yield k, me[k]
 753   def keys(me):
 754     return [k for k in me]
 755   def values(me):
 756     return [me[k] for k in me]
 757   def items(me):
 758     return [(k, me[k]) for k in me]
 759 eccurves = _groupmap(_base._eccurves, ECInfo._curven)
 760 primegroups = _groupmap(_base._pgroups, DHInfo._groupn)
 761 bingroups = _groupmap(_base._bingroups, BinDHInfo._groupn)
 762
 763 ###--------------------------------------------------------------------------
 764 ### Prime number generation.
 765
 766 class PrimeGenEventHandler (object):
 767   def pg_begin(me, ev):
 768     return me.pg_try(ev)
 769   def pg_done(me, ev):
 770     return PGEN_DONE
 771   def pg_abort(me, ev):
 772     return PGEN_TRY
 773   def pg_fail(me, ev):
 774     return PGEN_TRY
 775   def pg_pass(me, ev):
 776     return PGEN_TRY
 777
 778 class SophieGermainStepJump (object):
 779   def pg_begin(me, ev):
 780     me.lf = PrimeFilter(ev.x)
 781     me.hf = me.lf.muladd(2, 1)
 782     return me.cont(ev)
 783   def pg_try(me, ev):
 784     me.step()
 785     return me.cont(ev)
 786   def cont(me, ev):
 787     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 788       me.step()
 789     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 790       return PGEN_ABORT
 791     ev.x = me.lf.x
 792     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 793       return PGEN_DONE
 794     return PGEN_TRY
 795   def pg_done(me, ev):
 796     del me.lf
 797     del me.hf
 798
 799 class SophieGermainStepper (SophieGermainStepJump):
 800   def __init__(me, step):
 801     me.lstep = step;
 802     me.hstep = 2 * step
 803   def step(me):
 804     me.lf.step(me.lstep)
 805     me.hf.step(me.hstep)
 806
 807 class SophieGermainJumper (SophieGermainStepJump):
 808   def __init__(me, jump):
 809     me.ljump = PrimeFilter(jump);
 810     me.hjump = me.ljump.muladd(2, 0)
 811   def step(me):
 812     me.lf.jump(me.ljump)
 813     me.hf.jump(me.hjump)
 814   def pg_done(me, ev):
 815     del me.ljump
 816     del me.hjump
 817     SophieGermainStepJump.pg_done(me, ev)
 818
 819 class SophieGermainTester (object):
 820   def __init__(me):
 821     pass
 822   def pg_begin(me, ev):
 823     me.lr = RabinMiller(ev.x)
 824     me.hr = RabinMiller(2 * ev.x + 1)
 825   def pg_try(me, ev):
 826     lst = me.lr.test(ev.rng.range(me.lr.x))
 827     if lst != PGEN_PASS and lst != PGEN_DONE:
 828       return lst
 829     rst = me.hr.test(ev.rng.range(me.hr.x))
 830     if rst != PGEN_PASS and rst != PGEN_DONE:
 831       return rst
 832     if lst == PGEN_DONE and rst == PGEN_DONE:
 833       return PGEN_DONE
 834     return PGEN_PASS
 835   def pg_done(me, ev):
 836     del me.lr
 837     del me.hr
 838
 839 class PrimitiveStepper (PrimeGenEventHandler):
 840   def __init__(me):
 841     pass
 842   def pg_try(me, ev):
 843     ev.x = me.i.next()
 844     return PGEN_TRY
 845   def pg_begin(me, ev):
 846     me.i = iter(smallprimes)
 847     return me.pg_try(ev)
 848
 849 class PrimitiveTester (PrimeGenEventHandler):
 850   def __init__(me, mod, hh = [], exp = None):
 851     me.mod = MPMont(mod)
 852     me.exp = exp
 853     me.hh = hh
 854   def pg_try(me, ev):
 855     x = ev.x
 856     if me.exp is not None:
 857       x = me.mod.exp(x, me.exp)
 858       if x == 1: return PGEN_FAIL
 859     for h in me.hh:
 860       if me.mod.exp(x, h) == 1: return PGEN_FAIL
 861     ev.x = x
 862     return PGEN_DONE
 863
 864 class SimulStepper (PrimeGenEventHandler):
 865   def __init__(me, mul = 2, add = 1, step = 2):
 866     me.step = step
 867     me.mul = mul
 868     me.add = add
 869   def _stepfn(me, step):
 870     if step <= 0:
 871       raise ValueError, 'step must be positive'
 872     if step <= MPW_MAX:
 873       return lambda f: f.step(step)
 874     j = PrimeFilter(step)
 875     return lambda f: f.jump(j)
 876   def pg_begin(me, ev):
 877     x = ev.x
 878     me.lf = PrimeFilter(x)
 879     me.hf = PrimeFilter(x * me.mul + me.add)
 880     me.lstep = me._stepfn(me.step)
 881     me.hstep = me._stepfn(me.step * me.mul)
 882     SimulStepper._cont(me, ev)
 883   def pg_try(me, ev):
 884     me._step()
 885     me._cont(ev)
 886   def _step(me):
 887     me.lstep(me.lf)
 888     me.hstep(me.hf)
 889   def _cont(me, ev):
 890     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 891       me._step()
 892     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 893       return PGEN_ABORT
 894     ev.x = me.lf.x
 895     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 896       return PGEN_DONE
 897     return PGEN_TRY
 898   def pg_done(me, ev):
 899     del me.lf
 900     del me.hf
 901     del me.lstep
 902     del me.hstep
 903
 904 class SimulTester (PrimeGenEventHandler):
 905   def __init__(me, mul = 2, add = 1):
 906     me.mul = mul
 907     me.add = add
 908   def pg_begin(me, ev):
 909     x = ev.x
 910     me.lr = RabinMiller(x)
 911     me.hr = RabinMiller(x * me.mul + me.add)
 912   def pg_try(me, ev):
 913     lst = me.lr.test(ev.rng.range(me.lr.x))
 914     if lst != PGEN_PASS and lst != PGEN_DONE:
 915       return lst
 916     rst = me.hr.test(ev.rng.range(me.hr.x))
 917     if rst != PGEN_PASS and rst != PGEN_DONE:
 918       return rst
 919     if lst == PGEN_DONE and rst == PGEN_DONE:
 920       return PGEN_DONE
 921     return PGEN_PASS
 922   def pg_done(me, ev):
 923     del me.lr
 924     del me.hr
 925
 926 def sgprime(start, step = 2, name = 'p', event = pgen_nullev, nsteps = 0):
 927   start = MP(start)
 928   return pgen(start, name, SimulStepper(step = step), SimulTester(), event,
 929               nsteps, RabinMiller.iters(start.nbits))
 930
 931 def findprimitive(mod, hh = [], exp = None, name = 'g', event = pgen_nullev):
 932   return pgen(0, name, PrimitiveStepper(), PrimitiveTester(mod, hh, exp),
 933               event, 0, 1)
 934
 935 def kcdsaprime(pbits, qbits, rng = rand,
 936                event = pgen_nullev, name = 'p', nsteps = 0):
 937   hbits = pbits - qbits
 938   h = pgen(rng.mp(hbits, 1), name + ' [h]',
 939            PrimeGenStepper(2), PrimeGenTester(),
 940            event, nsteps, RabinMiller.iters(hbits))
 941   q = pgen(rng.mp(qbits, 1), name, SimulStepper(2 * h, 1, 2),
 942            SimulTester(2 * h, 1), event, nsteps, RabinMiller.iters(qbits))
 943   p = 2 * q * h + 1
 944   return p, q, h
 945
 946 #----- That's all, folks ----------------------------------------------------