(bc.blksz - 1, 3*bc.blksz - 5, 3*bc.blksz + 5)]
###--------------------------------------------------------------------------
+### PMAC.
+
+def ocb_masks(E):
+ blksz = E.__class__.blksz
+ p = poly(8*blksz)
+ x = C.GF(2); xinv = p.modinv(x)
+ z = Z(blksz)
+ L = E.encrypt(z)
+ Lxinv = mul_blk_gf(L, xinv, p)
+ Lgamma = 66*[L]
+ for i in xrange(1, len(Lgamma)):
+ Lgamma[i] = mul_blk_gf(Lgamma[i - 1], x, p)
+ return Lgamma, Lxinv
+
+def dump_ocb(E):
+ Lgamma, Lxinv = ocb_masks(E)
+ print 'L x^-1 = %s' % hex(Lxinv)
+ for i, lg in enumerate(Lgamma[:16]):
+ print 'L x^%d = %s' % (i, hex(lg))
+
+def pmac1(E, m):
+ blksz = E.__class__.blksz
+ Lgamma, Lxinv = ocb_masks(E)
+ a = o = Z(blksz)
+ i = 0
+ v, tl = blocks(m, blksz)
+ for x in v:
+ i += 1
+ b = ntz(i)
+ o ^= Lgamma[b]
+ a ^= E.encrypt(x ^ o)
+ if VERBOSE:
+ print 'Z[%d]: %d -> %s' % (i, b, hex(o))
+ print 'A[%d]: %s' % (i, hex(a))
+ if len(tl) == blksz: a ^= tl ^ Lxinv
+ else: a ^= pad10star(tl, blksz)
+ return E.encrypt(a)
+
+def pmac1_pub(E, m):
+ if VERBOSE: dump_ocb(E)
+ return pmac1(E, m),
+
+def pmacgen(bc):
+ return [(0,), (1,),
+ (3*bc.blksz,),
+ (3*bc.blksz - 5,)]
+
+###--------------------------------------------------------------------------
+### OCB.
+
+def ocb1enc(E, n, h, m, tsz = None):
+ ## This is OCB1.PMAC1 from Rogaway's `Authenticated-Encryption with
+ ## Associated-Data'.
+ blksz = E.__class__.blksz
+ if VERBOSE: dump_ocb(E)
+ Lgamma, Lxinv = ocb_masks(E)
+ if tsz is None: tsz = blksz
+ a = Z(blksz)
+ o = E.encrypt(n ^ Lgamma[0])
+ if VERBOSE: print 'R = %s' % hex(o)
+ i = 0
+ y = C.WriteBuffer()
+ v, tl = blocks(m, blksz)
+ for x in v:
+ i += 1
+ b = ntz(i)
+ o ^= Lgamma[b]
+ a ^= x
+ if VERBOSE:
+ print 'Z[%d]: %d -> %s' % (i, b, hex(o))
+ print 'A[%d]: %s' % (i, hex(a))
+ y.put(E.encrypt(x ^ o) ^ o)
+ i += 1
+ b = ntz(i)
+ o ^= Lgamma[b]
+ n = len(tl)
+ if VERBOSE:
+ print 'Z[%d]: %d -> %s' % (i, b, hex(o))
+ print 'LEN = %s' % hex(C.MP(8*n).storeb(blksz))
+ yfinal = E.encrypt(C.MP(8*n).storeb(blksz) ^ Lxinv ^ o)
+ cfinal = tl ^ yfinal[:n]
+ a ^= o ^ (tl + yfinal[n:])
+ y.put(cfinal)
+ t = E.encrypt(a)
+ if h: t ^= pmac1(E, h)
+ return C.ByteString(y), C.ByteString(t[:tsz])
+
+def ocb1dec(E, n, h, y, t):
+ ## This is OCB1.PMAC1 from Rogaway's `Authenticated-Encryption with
+ ## Associated-Data'.
+ blksz = E.__class__.blksz
+ if VERBOSE: dump_ocb(E)
+ Lgamma, Lxinv = ocb_masks(E)
+ a = Z(blksz)
+ o = E.encrypt(n ^ Lgamma[0])
+ if VERBOSE: print 'R = %s' % hex(o)
+ i = 0
+ m = C.WriteBuffer()
+ v, tl = blocks(y, blksz)
+ for x in v:
+ i += 1
+ b = ntz(i)
+ o ^= Lgamma[b]
+ if VERBOSE:
+ print 'Z[%d]: %d -> %s' % (i, b, hex(o))
+ print 'A[%d]: %s' % (i, hex(a))
+ u = E.decrypt(x ^ o) ^ o
+ m.put(u)
+ a ^= u
+ i += 1
+ b = ntz(i)
+ o ^= Lgamma[b]
+ n = len(tl)
+ if VERBOSE:
+ print 'Z[%d]: %d -> %s' % (i, b, hex(o))
+ print 'LEN = %s' % hex(C.MP(8*n).storeb(blksz))
+ yfinal = E.encrypt(C.MP(8*n).storeb(blksz) ^ Lxinv ^ o)
+ mfinal = tl ^ yfinal[:n]
+ a ^= o ^ (mfinal + yfinal[n:])
+ m.put(mfinal)
+ u = E.encrypt(a)
+ if h: u ^= pmac1(E, h)
+ if t == u[:len(t)]: return C.ByteString(m),
+ else: return None,
+
+def ocbgen(bc):
+ w = bc.blksz
+ return [(w, 0, 0), (w, 1, 0), (w, 0, 1),
+ (w, 0, 3*w),
+ (w, 3*w, 3*w),
+ (w, 0, 3*w + 5),
+ (w, 3*w - 5, 3*w + 5)]
+
+###--------------------------------------------------------------------------
### Main program.
class struct (object):
'ccm-dec': (dummygen, 4*[binarg], ccmdec),
'cmac': (cmacgen, [binarg], cmac),
'gcm-enc': (gcmgen, 3*[binarg] + [intarg], gcmenc),
- 'gcm-dec': (dummygen, 4*[binarg], gcmdec) }
+ 'gcm-dec': (dummygen, 4*[binarg], gcmdec),
+ 'ocb1-enc': (ocbgen, 3*[binarg] + [intarg], ocb1enc),
+ 'ocb1-dec': (dummygen, 4*[binarg], ocb1dec),
+ 'pmac1': (pmacgen, [binarg], pmac1_pub) }
mode = argv[1]
bc = None