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 _pp_str(me, pp, cyclep): pp.text(cyclep and '...' or str(me))
  87 def _pp_kv(pp, k, v):
  88   ind = len(k) + 3
  89   pp.begin_group(ind, k + ' = ')
  90   pp.pretty(v)
  91   pp.end_group(ind, '')
  92 def _pp_commas(pp, printfn, items):
  93   firstp = True
  94   for i in items:
  95     if firstp: firstp = False
  96     else: pp.text(','); pp.breakable()
  97     printfn(i)
  98 def _pp_dict(pp, items):
  99   def p((k, v)):
 100     pp.begin_group(0, '')
 101     pp.pretty(k)
 102     pp.text(':')
 103     pp.begin_group(2, '')
 104     pp.breakable()
 105     pp.pretty(v)
 106     pp.end_group(2, '')
 107     pp.end_group(0, '')
 108   _pp_commas(pp, p, items)
 109
 110 ###--------------------------------------------------------------------------
 111 ### Bytestrings.
 112
 113 class _tmp:
 114   def fromhex(x):
 115     return ByteString(_unhexify(x))
 116   fromhex = staticmethod(fromhex)
 117   def __hex__(me):
 118     return _hexify(me)
 119   def __repr__(me):
 120     return 'bytes(%r)' % hex(me)
 121 _augment(ByteString, _tmp)
 122 ByteString.__hash__ = str.__hash__
 123 bytes = ByteString.fromhex
 124
 125 ###--------------------------------------------------------------------------
 126 ### Hashing.
 127
 128 class _tmp:
 129   def check(me, h):
 130     hh = me.done()
 131     return ctstreq(h, hh)
 132 _augment(GHash, _tmp)
 133 _augment(Poly1305Hash, _tmp)
 134
 135 ###--------------------------------------------------------------------------
 136 ### NaCl `secretbox'.
 137
 138 def secret_box(k, n, m):
 139   E = xsalsa20(k).setiv(n)
 140   r = E.enczero(poly1305.keysz.default)
 141   s = E.enczero(poly1305.masksz)
 142   y = E.encrypt(m)
 143   t = poly1305(r)(s).hash(y).done()
 144   return ByteString(t + y)
 145
 146 def secret_unbox(k, n, c):
 147   E = xsalsa20(k).setiv(n)
 148   r = E.enczero(poly1305.keysz.default)
 149   s = E.enczero(poly1305.masksz)
 150   y = c[poly1305.tagsz:]
 151   if not poly1305(r)(s).hash(y).check(c[0:poly1305.tagsz]):
 152     raise ValueError, 'decryption failed'
 153   return E.decrypt(c[poly1305.tagsz:])
 154
 155 ###--------------------------------------------------------------------------
 156 ### Multiprecision integers and binary polynomials.
 157
 158 def _split_rat(x):
 159   if isinstance(x, BaseRat): return x._n, x._d
 160   else: return x, 1
 161 class BaseRat (object):
 162   """Base class implementing fields of fractions over Euclidean domains."""
 163   def __new__(cls, a, b):
 164     a, b = cls.RING(a), cls.RING(b)
 165     q, r = divmod(a, b)
 166     if r == 0: return q
 167     g = b.gcd(r)
 168     me = super(BaseRat, cls).__new__(cls)
 169     me._n = a//g
 170     me._d = b//g
 171     return me
 172   @property
 173   def numer(me): return me._n
 174   @property
 175   def denom(me): return me._d
 176   def __str__(me): return '%s/%s' % (me._n, me._d)
 177   def __repr__(me): return '%s(%s, %s)' % (type(me).__name__, me._n, me._d)
 178   _repr_pretty_ = _pp_str
 179
 180   def __add__(me, you):
 181     n, d = _split_rat(you)
 182     return type(me)(me._n*d + n*me._d, d*me._d)
 183   __radd__ = __add__
 184   def __sub__(me, you):
 185     n, d = _split_rat(you)
 186     return type(me)(me._n*d - n*me._d, d*me._d)
 187   def __rsub__(me, you):
 188     n, d = _split_rat(you)
 189     return type(me)(n*me._d - me._n*d, d*me._d)
 190   def __mul__(me, you):
 191     n, d = _split_rat(you)
 192     return type(me)(me._n*n, me._d*d)
 193   def __div__(me, you):
 194     n, d = _split_rat(you)
 195     return type(me)(me._n*d, me._d*n)
 196   def __rdiv__(me, you):
 197     n, d = _split_rat(you)
 198     return type(me)(me._d*n, me._n*d)
 199   def __cmp__(me, you):
 200     n, d = _split_rat(you)
 201     return type(me)(me._n*d, n*me._d)
 202   def __rcmp__(me, you):
 203     n, d = _split_rat(you)
 204     return cmp(n*me._d, me._n*d)
 205
 206 class IntRat (BaseRat):
 207   RING = MP
 208
 209 class GFRat (BaseRat):
 210   RING = GF
 211
 212 class _tmp:
 213   def negp(x): return x < 0
 214   def posp(x): return x > 0
 215   def zerop(x): return x == 0
 216   def oddp(x): return x.testbit(0)
 217   def evenp(x): return not x.testbit(0)
 218   def mont(x): return MPMont(x)
 219   def barrett(x): return MPBarrett(x)
 220   def reduce(x): return MPReduce(x)
 221   def __div__(me, you): return IntRat(me, you)
 222   def __rdiv__(me, you): return IntRat(you, me)
 223   _repr_pretty_ = _pp_str
 224 _augment(MP, _tmp)
 225
 226 class _tmp:
 227   def zerop(x): return x == 0
 228   def reduce(x): return GFReduce(x)
 229   def trace(x, y): return x.reduce().trace(y)
 230   def halftrace(x, y): return x.reduce().halftrace(y)
 231   def modsqrt(x, y): return x.reduce().sqrt(y)
 232   def quadsolve(x, y): return x.reduce().quadsolve(y)
 233   def __div__(me, you): return GFRat(me, you)
 234   def __rdiv__(me, you): return GFRat(you, me)
 235   _repr_pretty_ = _pp_str
 236 _augment(GF, _tmp)
 237
 238 class _tmp:
 239   def product(*arg):
 240     'product(ITERABLE) or product(I, ...) -> PRODUCT'
 241     return MPMul(*arg).done()
 242   product = staticmethod(product)
 243 _augment(MPMul, _tmp)
 244
 245 ###--------------------------------------------------------------------------
 246 ### Abstract fields.
 247
 248 class _tmp:
 249   def fromstring(str): return _checkend(Field.parse(str))
 250   fromstring = staticmethod(fromstring)
 251 _augment(Field, _tmp)
 252
 253 class _tmp:
 254   def __repr__(me): return '%s(%sL)' % (type(me).__name__, me.p)
 255   def __hash__(me): return 0x114401de ^ hash(me.p)
 256   def _repr_pretty_(me, pp, cyclep):
 257     tyname = type(me).__name__
 258     if cyclep:
 259       pp.text(tyname + '(...)')
 260     else:
 261       ind = len(tyname) + 1
 262       pp.begin_group(ind, tyname + '(')
 263       pp.pretty(me.p)
 264       pp.end_group(ind, ')')
 265   def ec(me, a, b): return ECPrimeProjCurve(me, a, b)
 266 _augment(PrimeField, _tmp)
 267
 268 class _tmp:
 269   def __repr__(me): return '%s(%#xL)' % (type(me).__name__, me.p)
 270   def ec(me, a, b): return ECBinProjCurve(me, a, b)
 271   def _repr_pretty_(me, pp, cyclep):
 272     tyname = type(me).__name__
 273     if cyclep:
 274       pp.text(tyname + '(...)')
 275     else:
 276       ind = len(tyname) + 1
 277       pp.begin_group(ind, tyname + '(')
 278       pp.text('%#x' % me.p)
 279       pp.end_group(ind, ')')
 280 _augment(BinField, _tmp)
 281
 282 class _tmp:
 283   def __hash__(me): return 0x23e4701c ^ hash(me.p)
 284 _augment(BinPolyField, _tmp)
 285
 286 class _tmp:
 287   def __hash__(me):
 288     h = 0x9a7d6240
 289     h ^=   hash(me.p)
 290     h ^= 2*hash(me.beta) & 0xffffffff
 291     return h
 292 _augment(BinNormField, _tmp)
 293
 294 class _tmp:
 295   def __str__(me): return str(me.value)
 296   def __repr__(me): return '%s(%s)' % (repr(me.field), repr(me.value))
 297   _repr_pretty_ = _pp_str
 298 _augment(FE, _tmp)
 299
 300 ###--------------------------------------------------------------------------
 301 ### Elliptic curves.
 302
 303 class _tmp:
 304   def __repr__(me):
 305     return '%s(%r, %s, %s)' % (type(me).__name__, me.field, me.a, me.b)
 306   def _repr_pretty_(me, pp, cyclep):
 307     tyname = type(me).__name__
 308     if cyclep:
 309       pp.text(tyname + '(...)')
 310     else:
 311       ind = len(tyname) + 1
 312       pp.begin_group(ind, tyname + '(')
 313       pp.pretty(me.field); pp.text(','); pp.breakable()
 314       pp.pretty(me.a); pp.text(','); pp.breakable()
 315       pp.pretty(me.b)
 316       pp.end_group(ind, ')')
 317   def frombuf(me, s):
 318     return ecpt.frombuf(me, s)
 319   def fromraw(me, s):
 320     return ecpt.fromraw(me, s)
 321   def pt(me, *args):
 322     return me(*args)
 323 _augment(ECCurve, _tmp)
 324
 325 class _tmp:
 326   def __hash__(me):
 327     h = 0x6751d341
 328     h ^=   hash(me.field)
 329     h ^= 2*hash(me.a) ^ 0xffffffff
 330     h ^= 5*hash(me.b) ^ 0xffffffff
 331     return h
 332 _augment(ECPrimeCurve, _tmp)
 333
 334 class _tmp:
 335   def __hash__(me):
 336     h = 0x2ac203c5
 337     h ^=   hash(me.field)
 338     h ^= 2*hash(me.a) ^ 0xffffffff
 339     h ^= 5*hash(me.b) ^ 0xffffffff
 340     return h
 341 _augment(ECBinCurve, _tmp)
 342
 343 class _tmp:
 344   def __repr__(me):
 345     if not me: return 'ECPt()'
 346     return 'ECPt(%s, %s)' % (me.ix, me.iy)
 347   def __str__(me):
 348     if not me: return 'inf'
 349     return '(%s, %s)' % (me.ix, me.iy)
 350   def _repr_pretty_(me, pp, cyclep):
 351     if cyclep:
 352       pp.text('...')
 353     elif not me:
 354       pp.text('inf')
 355     else:
 356       pp.begin_group(1, '(')
 357       pp.pretty(me.ix); pp.text(','); pp.breakable()
 358       pp.pretty(me.iy)
 359       pp.end_group(1, ')')
 360 _augment(ECPt, _tmp)
 361
 362 class _tmp:
 363   def __repr__(me):
 364     return 'ECInfo(curve = %r, G = %r, r = %s, h = %s)' % \
 365            (me.curve, me.G, me.r, me.h)
 366   def _repr_pretty_(me, pp, cyclep):
 367     if cyclep:
 368       pp.text('ECInfo(...)')
 369     else:
 370       pp.begin_group(7, 'ECInfo(')
 371       _pp_kv(pp, 'curve', me.curve); pp.text(','); pp.breakable()
 372       _pp_kv(pp, 'G', me.G); pp.text(','); pp.breakable()
 373       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 374       _pp_kv(pp, 'h', me.h)
 375       pp.end_group(7, ')')
 376   def __hash__(me):
 377     h = 0x9bedb8de
 378     h ^=   hash(me.curve)
 379     h ^= 2*hash(me.G) & 0xffffffff
 380     return h
 381   def group(me):
 382     return ECGroup(me)
 383 _augment(ECInfo, _tmp)
 384
 385 class _tmp:
 386   def __repr__(me):
 387     if not me: return '%r()' % (me.curve)
 388     return '%r(%s, %s)' % (me.curve, me.x, me.y)
 389   def __str__(me):
 390     if not me: return 'inf'
 391     return '(%s, %s)' % (me.x, me.y)
 392 _augment(ECPtCurve, _tmp)
 393
 394 ###--------------------------------------------------------------------------
 395 ### Key sizes.
 396
 397 class _tmp:
 398   def __repr__(me): return 'KeySZAny(%d)' % me.default
 399   def check(me, sz): return True
 400   def best(me, sz): return sz
 401 _augment(KeySZAny, _tmp)
 402
 403 class _tmp:
 404   def __repr__(me):
 405     return 'KeySZRange(%d, %d, %d, %d)' % \
 406            (me.default, me.min, me.max, me.mod)
 407   def _repr_pretty_(me, pp, cyclep):
 408     if cyclep:
 409       pp.text('KeySZRange(...)')
 410     else:
 411       pp.begin_group(11, 'KeySZRange(')
 412       pp.pretty(me.default); pp.text(','); pp.breakable()
 413       pp.pretty(me.min); pp.text(','); pp.breakable()
 414       pp.pretty(me.max); pp.text(','); pp.breakable()
 415       pp.pretty(me.mod)
 416       pp.end_group(11, ')')
 417   def check(me, sz): return me.min <= sz <= me.max and sz % me.mod == 0
 418   def best(me, sz):
 419     if sz < me.min: raise ValueError, 'key too small'
 420     elif sz > me.max: return me.max
 421     else: return sz - (sz % me.mod)
 422 _augment(KeySZRange, _tmp)
 423
 424 class _tmp:
 425   def __repr__(me): return 'KeySZSet(%d, %s)' % (me.default, me.set)
 426   def _repr_pretty_(me, pp, cyclep):
 427     if cyclep:
 428       pp.text('KeySZSet(...)')
 429     else:
 430       pp.begin_group(9, 'KeySZSet(')
 431       pp.pretty(me.default); pp.text(','); pp.breakable()
 432       pp.begin_group(1, '{')
 433       _pp_commas(pp, pp.pretty, me.set)
 434       pp.end_group(1, '}')
 435       pp.end_group(9, ')')
 436   def check(me, sz): return sz in me.set
 437   def best(me, sz):
 438     found = -1
 439     for i in me.set:
 440       if found < i <= sz: found = i
 441     if found < 0: raise ValueError, 'key too small'
 442     return found
 443 _augment(KeySZSet, _tmp)
 444
 445 ###--------------------------------------------------------------------------
 446 ### Key data objects.
 447
 448 class _tmp:
 449   def __repr__(me): return 'KeyFile(%r)' % me.name
 450 _augment(KeyFile, _tmp)
 451
 452 class _tmp:
 453   def __repr__(me): return 'Key(%r)' % me.fulltag
 454 _augment(Key, _tmp)
 455
 456 class _tmp:
 457   def __repr__(me):
 458     return 'KeyAttributes({%s})' % \
 459         ', '.join(['%r: %r' % kv for kv in me.iteritems()])
 460   def _repr_pretty_(me, pp, cyclep):
 461     pp.begin_group(14, 'KeyAttributes(')
 462     if cyclep: pp.text('...')
 463     else: _pp_dict(pp, me.iteritems())
 464     pp.end_group(14, ')')
 465 _augment(KeyAttributes, _tmp)
 466
 467 class _tmp:
 468   def __repr__(me): return 'KeyDataBinary(%r, %r)' % \
 469         (me.bin, me.writeflags(me.flags))
 470   def _repr_pretty_(me, pp, cyclep):
 471     pp.begin_group(14, 'KeyDataBinary(')
 472     if cyclep:
 473       pp.text('KeyDataBinary(...)')
 474     else:
 475       pp.pretty(me.bin); pp.text(','); pp.breakable()
 476       pp.pretty(me.writeflags(me.flags))
 477     pp.end_group(14, ')')
 478 _augment(KeyDataBinary, _tmp)
 479
 480 class _tmp:
 481   def __repr__(me): return 'KeyDataEncrypted(%r, %r)' % \
 482         (me.ct, me.writeflags(me.flags))
 483   def _repr_pretty_(me, pp, cyclep):
 484     pp.begin_group(17, 'KeyDataEncrypted(')
 485     if cyclep:
 486       pp.text('...')
 487     else:
 488       pp.pretty(me.ct); pp.text(','); pp.breakable()
 489       pp.pretty(me.writeflags(me.flags))
 490     pp.end_group(17, ')')
 491 _augment(KeyDataEncrypted, _tmp)
 492
 493 class _tmp:
 494   def __repr__(me): return 'KeyDataMP(%r, %r)' % \
 495         (me.mp, me.writeflags(me.flags))
 496   def _repr_pretty_(me, pp, cyclep):
 497     pp.begin_group(10, 'KeyDataMP(')
 498     if cyclep:
 499       pp.text('...')
 500     else:
 501       pp.pretty(me.mp); pp.text(','); pp.breakable()
 502       pp.pretty(me.writeflags(me.flags))
 503     pp.end_group(10, ')')
 504 _augment(KeyDataMP, _tmp)
 505
 506 class _tmp:
 507   def __repr__(me): return 'KeyDataString(%r)' % \
 508         (me.str, me.writeflags(me.flags))
 509   def _repr_pretty_(me, pp, cyclep):
 510     pp.begin_group(14, 'KeyDataString(')
 511     if cyclep:
 512       pp.text('...')
 513     else:
 514       pp.pretty(me.str); pp.text(','); pp.breakable()
 515       pp.pretty(me.writeflags(me.flags))
 516     pp.end_group(14, ')')
 517 _augment(KeyDataString, _tmp)
 518
 519 class _tmp:
 520   def __repr__(me): return 'KeyDataECPt(%r)' % \
 521         (me.ecpt, me.writeflags(me.flags))
 522   def _repr_pretty_(me, pp, cyclep):
 523     pp.begin_group(12, 'KeyDataECPt(')
 524     if cyclep:
 525       pp.text('...')
 526     else:
 527       pp.pretty(me.ecpt); pp.text(','); pp.breakable()
 528       pp.pretty(me.writeflags(me.flags))
 529     pp.end_group(12, ')')
 530 _augment(KeyDataECPt, _tmp)
 531
 532 class _tmp:
 533   def __repr__(me):
 534     return 'KeyDataStructured({%s})' % \
 535         ', '.join(['%r: %r' % kv for kv in me.iteritems()])
 536   def _repr_pretty_(me, pp, cyclep):
 537     pp.begin_group(20, 'KeyDataStructured({ ')
 538     if cyclep: pp.text('...')
 539     else: _pp_dict(pp, me.iteritems())
 540     pp.end_group(20, ' })')
 541 _augment(KeyDataStructured, _tmp)
 542
 543 ###--------------------------------------------------------------------------
 544 ### Abstract groups.
 545
 546 class _tmp:
 547   def __repr__(me):
 548     return '%s(p = %s, r = %s, g = %s)' % \
 549            (type(me).__name__, me.p, me.r, me.g)
 550   def _repr_pretty_(me, pp, cyclep):
 551     tyname = type(me).__name__
 552     if cyclep:
 553       pp.text(tyname + '(...)')
 554     else:
 555       ind = len(tyname) + 1
 556       pp.begin_group(ind, tyname + '(')
 557       _pp_kv(pp, 'p', me.p); pp.text(','); pp.breakable()
 558       _pp_kv(pp, 'r', me.r); pp.text(','); pp.breakable()
 559       _pp_kv(pp, 'g', me.g)
 560       pp.end_group(ind, ')')
 561 _augment(FGInfo, _tmp)
 562
 563 class _tmp:
 564   def group(me): return PrimeGroup(me)
 565 _augment(DHInfo, _tmp)
 566
 567 class _tmp:
 568   def group(me): return BinGroup(me)
 569 _augment(BinDHInfo, _tmp)
 570
 571 class _tmp:
 572   def __repr__(me):
 573     return '%s(%r)' % (type(me).__name__, me.info)
 574 _augment(Group, _tmp)
 575
 576 class _tmp:
 577   def __hash__(me):
 578     info = me.info
 579     h = 0xbce3cfe6
 580     h ^=   hash(info.p)
 581     h ^= 2*hash(info.r) & 0xffffffff
 582     h ^= 5*hash(info.g) & 0xffffffff
 583     return h
 584 _augment(PrimeGroup, _tmp)
 585
 586 class _tmp:
 587   def __hash__(me):
 588     info = me.info
 589     h = 0x80695949
 590     h ^=   hash(info.p)
 591     h ^= 2*hash(info.r) & 0xffffffff
 592     h ^= 5*hash(info.g) & 0xffffffff
 593     return h
 594 _augment(BinGroup, _tmp)
 595
 596 class _tmp:
 597   def __hash__(me): return 0x0ec23dab ^ hash(me.info)
 598 _augment(ECGroup, _tmp)
 599
 600 class _tmp:
 601   def __repr__(me):
 602     return '%r(%r)' % (me.group, str(me))
 603   _repr_pretty_ = _pp_str
 604 _augment(GE, _tmp)
 605
 606 ###--------------------------------------------------------------------------
 607 ### RSA encoding techniques.
 608
 609 class PKCS1Crypt (object):
 610   def __init__(me, ep = '', rng = rand):
 611     me.ep = ep
 612     me.rng = rng
 613   def encode(me, msg, nbits):
 614     return _base._p1crypt_encode(msg, nbits, me.ep, me.rng)
 615   def decode(me, ct, nbits):
 616     return _base._p1crypt_decode(ct, nbits, me.ep, me.rng)
 617
 618 class PKCS1Sig (object):
 619   def __init__(me, ep = '', rng = rand):
 620     me.ep = ep
 621     me.rng = rng
 622   def encode(me, msg, nbits):
 623     return _base._p1sig_encode(msg, nbits, me.ep, me.rng)
 624   def decode(me, msg, sig, nbits):
 625     return _base._p1sig_decode(msg, sig, nbits, me.ep, me.rng)
 626
 627 class OAEP (object):
 628   def __init__(me, mgf = sha_mgf, hash = sha, ep = '', rng = rand):
 629     me.mgf = mgf
 630     me.hash = hash
 631     me.ep = ep
 632     me.rng = rng
 633   def encode(me, msg, nbits):
 634     return _base._oaep_encode(msg, nbits, me.mgf, me.hash, me.ep, me.rng)
 635   def decode(me, ct, nbits):
 636     return _base._oaep_decode(ct, nbits, me.mgf, me.hash, me.ep, me.rng)
 637
 638 class PSS (object):
 639   def __init__(me, mgf = sha_mgf, hash = sha, saltsz = None, rng = rand):
 640     me.mgf = mgf
 641     me.hash = hash
 642     if saltsz is None:
 643       saltsz = hash.hashsz
 644     me.saltsz = saltsz
 645     me.rng = rng
 646   def encode(me, msg, nbits):
 647     return _base._pss_encode(msg, nbits, me.mgf, me.hash, me.saltsz, me.rng)
 648   def decode(me, msg, sig, nbits):
 649     return _base._pss_decode(msg, sig, nbits,
 650                              me.mgf, me.hash, me.saltsz, me.rng)
 651
 652 class _tmp:
 653   def encrypt(me, msg, enc):
 654     return me.pubop(enc.encode(msg, me.n.nbits))
 655   def verify(me, msg, sig, enc):
 656     if msg is None: return enc.decode(msg, me.pubop(sig), me.n.nbits)
 657     try:
 658       x = enc.decode(msg, me.pubop(sig), me.n.nbits)
 659       return x is None or x == msg
 660     except ValueError:
 661       return False
 662 _augment(RSAPub, _tmp)
 663
 664 class _tmp:
 665   def decrypt(me, ct, enc): return enc.decode(me.privop(ct), me.n.nbits)
 666   def sign(me, msg, enc): return me.privop(enc.encode(msg, me.n.nbits))
 667 _augment(RSAPriv, _tmp)
 668
 669 ###--------------------------------------------------------------------------
 670 ### Bernstein's elliptic curve crypto and related schemes.
 671
 672 X25519_BASE = \
 673   bytes('0900000000000000000000000000000000000000000000000000000000000000')
 674
 675 X448_BASE = \
 676   bytes('05000000000000000000000000000000000000000000000000000000'
 677         '00000000000000000000000000000000000000000000000000000000')
 678
 679 Z128 = bytes('00000000000000000000000000000000')
 680
 681 class _BoxyPub (object):
 682   def __init__(me, pub, *kw, **kwargs):
 683     if len(pub) != me._PUBSZ: raise ValueError, 'bad public key'
 684     super(_BoxyPub, me).__init__(*kw, **kwargs)
 685     me.pub = pub
 686
 687 class _BoxyPriv (_BoxyPub):
 688   def __init__(me, priv, pub = None, *kw, **kwargs):
 689     if len(priv) != me._KEYSZ: raise ValueError, 'bad private key'
 690     if pub is None: pub = me._op(priv, me._BASE)
 691     super(_BoxyPriv, me).__init__(pub = pub, *kw, **kwargs)
 692     me.priv = priv
 693   def agree(me, you): return me._op(me.priv, you.pub)
 694   def boxkey(me, recip):
 695     return me._hashkey(me.agree(recip))
 696   def box(me, recip, n, m):
 697     return secret_box(me.boxkey(recip), n, m)
 698   def unbox(me, recip, n, c):
 699     return secret_unbox(me.boxkey(recip, n, c))
 700
 701 class X25519Pub (_BoxyPub):
 702   _PUBSZ = X25519_PUBSZ
 703   _BASE = X25519_BASE
 704
 705 class X25519Priv (_BoxyPriv, X25519Pub):
 706   _KEYSZ = X25519_KEYSZ
 707   def _op(me, k, X): return x25519(k, X)
 708   def _hashkey(me, z): return hsalsa20_prf(z, Z128)
 709
 710 class X448Pub (_BoxyPub):
 711   _PUBSZ = X448_PUBSZ
 712   _BASE = X448_BASE
 713
 714 class X448Priv (_BoxyPriv, X448Pub):
 715   _KEYSZ = X448_KEYSZ
 716   def _op(me, k, X): return x448(k, X)
 717   ##def _hashkey(me, z): return ???
 718
 719 class Ed25519Pub (object):
 720   def __init__(me, pub):
 721     me.pub = pub
 722   def verify(me, msg, sig):
 723     return ed25519_verify(me.pub, msg, sig)
 724
 725 class Ed25519Priv (Ed25519Pub):
 726   def __init__(me, priv):
 727     me.priv = priv
 728     Ed25519Pub.__init__(me, ed25519_pubkey(priv))
 729   def sign(me, msg):
 730     return ed25519_sign(me.priv, msg, pub = me.pub)
 731   @classmethod
 732   def generate(cls, rng = rand):
 733     return cls(rng.block(ED25519_KEYSZ))
 734
 735 ###--------------------------------------------------------------------------
 736 ### Built-in named curves and prime groups.
 737
 738 class _groupmap (object):
 739   def __init__(me, map, nth):
 740     me.map = map
 741     me.nth = nth
 742     me._n = max(map.values()) + 1
 743     me.i = me._n*[None]
 744   def __repr__(me):
 745     return '{%s}' % ', '.join(['%r: %r' % kv for kv in me.iteritems()])
 746   def _repr_pretty_(me, pp, cyclep):
 747     if cyclep:
 748       pp.text('{ ... }')
 749     else:
 750       pp.begin_group(2, '{ ')
 751       _pp_dict(pp, me.iteritems())
 752       pp.end_group(2, ' }')
 753   def __len__(me):
 754     return me._n
 755   def __contains__(me, k):
 756     return k in me.map
 757   def __getitem__(me, k):
 758     i = me.map[k]
 759     if me.i[i] is None:
 760       me.i[i] = me.nth(i)
 761     return me.i[i]
 762   def __setitem__(me, k, v):
 763     raise TypeError, "immutable object"
 764   def __iter__(me):
 765     return iter(me.map)
 766   def iterkeys(me):
 767     return iter(me.map)
 768   def itervalues(me):
 769     for k in me:
 770       yield me[k]
 771   def iteritems(me):
 772     for k in me:
 773       yield k, me[k]
 774   def keys(me):
 775     return [k for k in me]
 776   def values(me):
 777     return [me[k] for k in me]
 778   def items(me):
 779     return [(k, me[k]) for k in me]
 780 eccurves = _groupmap(_base._eccurves, ECInfo._curven)
 781 primegroups = _groupmap(_base._pgroups, DHInfo._groupn)
 782 bingroups = _groupmap(_base._bingroups, BinDHInfo._groupn)
 783
 784 ###--------------------------------------------------------------------------
 785 ### Prime number generation.
 786
 787 class PrimeGenEventHandler (object):
 788   def pg_begin(me, ev):
 789     return me.pg_try(ev)
 790   def pg_done(me, ev):
 791     return PGEN_DONE
 792   def pg_abort(me, ev):
 793     return PGEN_TRY
 794   def pg_fail(me, ev):
 795     return PGEN_TRY
 796   def pg_pass(me, ev):
 797     return PGEN_TRY
 798
 799 class SophieGermainStepJump (object):
 800   def pg_begin(me, ev):
 801     me.lf = PrimeFilter(ev.x)
 802     me.hf = me.lf.muladd(2, 1)
 803     return me.cont(ev)
 804   def pg_try(me, ev):
 805     me.step()
 806     return me.cont(ev)
 807   def cont(me, ev):
 808     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 809       me.step()
 810     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 811       return PGEN_ABORT
 812     ev.x = me.lf.x
 813     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 814       return PGEN_DONE
 815     return PGEN_TRY
 816   def pg_done(me, ev):
 817     del me.lf
 818     del me.hf
 819
 820 class SophieGermainStepper (SophieGermainStepJump):
 821   def __init__(me, step):
 822     me.lstep = step;
 823     me.hstep = 2 * step
 824   def step(me):
 825     me.lf.step(me.lstep)
 826     me.hf.step(me.hstep)
 827
 828 class SophieGermainJumper (SophieGermainStepJump):
 829   def __init__(me, jump):
 830     me.ljump = PrimeFilter(jump);
 831     me.hjump = me.ljump.muladd(2, 0)
 832   def step(me):
 833     me.lf.jump(me.ljump)
 834     me.hf.jump(me.hjump)
 835   def pg_done(me, ev):
 836     del me.ljump
 837     del me.hjump
 838     SophieGermainStepJump.pg_done(me, ev)
 839
 840 class SophieGermainTester (object):
 841   def __init__(me):
 842     pass
 843   def pg_begin(me, ev):
 844     me.lr = RabinMiller(ev.x)
 845     me.hr = RabinMiller(2 * ev.x + 1)
 846   def pg_try(me, ev):
 847     lst = me.lr.test(ev.rng.range(me.lr.x))
 848     if lst != PGEN_PASS and lst != PGEN_DONE:
 849       return lst
 850     rst = me.hr.test(ev.rng.range(me.hr.x))
 851     if rst != PGEN_PASS and rst != PGEN_DONE:
 852       return rst
 853     if lst == PGEN_DONE and rst == PGEN_DONE:
 854       return PGEN_DONE
 855     return PGEN_PASS
 856   def pg_done(me, ev):
 857     del me.lr
 858     del me.hr
 859
 860 class PrimitiveStepper (PrimeGenEventHandler):
 861   def __init__(me):
 862     pass
 863   def pg_try(me, ev):
 864     ev.x = me.i.next()
 865     return PGEN_TRY
 866   def pg_begin(me, ev):
 867     me.i = iter(smallprimes)
 868     return me.pg_try(ev)
 869
 870 class PrimitiveTester (PrimeGenEventHandler):
 871   def __init__(me, mod, hh = [], exp = None):
 872     me.mod = MPMont(mod)
 873     me.exp = exp
 874     me.hh = hh
 875   def pg_try(me, ev):
 876     x = ev.x
 877     if me.exp is not None:
 878       x = me.mod.exp(x, me.exp)
 879       if x == 1: return PGEN_FAIL
 880     for h in me.hh:
 881       if me.mod.exp(x, h) == 1: return PGEN_FAIL
 882     ev.x = x
 883     return PGEN_DONE
 884
 885 class SimulStepper (PrimeGenEventHandler):
 886   def __init__(me, mul = 2, add = 1, step = 2):
 887     me.step = step
 888     me.mul = mul
 889     me.add = add
 890   def _stepfn(me, step):
 891     if step <= 0:
 892       raise ValueError, 'step must be positive'
 893     if step <= MPW_MAX:
 894       return lambda f: f.step(step)
 895     j = PrimeFilter(step)
 896     return lambda f: f.jump(j)
 897   def pg_begin(me, ev):
 898     x = ev.x
 899     me.lf = PrimeFilter(x)
 900     me.hf = PrimeFilter(x * me.mul + me.add)
 901     me.lstep = me._stepfn(me.step)
 902     me.hstep = me._stepfn(me.step * me.mul)
 903     SimulStepper._cont(me, ev)
 904   def pg_try(me, ev):
 905     me._step()
 906     me._cont(ev)
 907   def _step(me):
 908     me.lstep(me.lf)
 909     me.hstep(me.hf)
 910   def _cont(me, ev):
 911     while me.lf.status == PGEN_FAIL or me.hf.status == PGEN_FAIL:
 912       me._step()
 913     if me.lf.status == PGEN_ABORT or me.hf.status == PGEN_ABORT:
 914       return PGEN_ABORT
 915     ev.x = me.lf.x
 916     if me.lf.status == PGEN_DONE and me.hf.status == PGEN_DONE:
 917       return PGEN_DONE
 918     return PGEN_TRY
 919   def pg_done(me, ev):
 920     del me.lf
 921     del me.hf
 922     del me.lstep
 923     del me.hstep
 924
 925 class SimulTester (PrimeGenEventHandler):
 926   def __init__(me, mul = 2, add = 1):
 927     me.mul = mul
 928     me.add = add
 929   def pg_begin(me, ev):
 930     x = ev.x
 931     me.lr = RabinMiller(x)
 932     me.hr = RabinMiller(x * me.mul + me.add)
 933   def pg_try(me, ev):
 934     lst = me.lr.test(ev.rng.range(me.lr.x))
 935     if lst != PGEN_PASS and lst != PGEN_DONE:
 936       return lst
 937     rst = me.hr.test(ev.rng.range(me.hr.x))
 938     if rst != PGEN_PASS and rst != PGEN_DONE:
 939       return rst
 940     if lst == PGEN_DONE and rst == PGEN_DONE:
 941       return PGEN_DONE
 942     return PGEN_PASS
 943   def pg_done(me, ev):
 944     del me.lr
 945     del me.hr
 946
 947 def sgprime(start, step = 2, name = 'p', event = pgen_nullev, nsteps = 0):
 948   start = MP(start)
 949   return pgen(start, name, SimulStepper(step = step), SimulTester(), event,
 950               nsteps, RabinMiller.iters(start.nbits))
 951
 952 def findprimitive(mod, hh = [], exp = None, name = 'g', event = pgen_nullev):
 953   return pgen(0, name, PrimitiveStepper(), PrimitiveTester(mod, hh, exp),
 954               event, 0, 1)
 955
 956 def kcdsaprime(pbits, qbits, rng = rand,
 957                event = pgen_nullev, name = 'p', nsteps = 0):
 958   hbits = pbits - qbits
 959   h = pgen(rng.mp(hbits, 1), name + ' [h]',
 960            PrimeGenStepper(2), PrimeGenTester(),
 961            event, nsteps, RabinMiller.iters(hbits))
 962   q = pgen(rng.mp(qbits, 1), name, SimulStepper(2 * h, 1, 2),
 963            SimulTester(2 * h, 1), event, nsteps, RabinMiller.iters(qbits))
 964   p = 2 * q * h + 1
 965   return p, q, h
 966
 967 #----- That's all, folks ----------------------------------------------------