Makefile, ocbgen: Handle 512-bit blocks.

Introduce a completely crazy 512-bit double-Luby--Rackoff stunt block
cipher to demonstrate.

diff --git a/Makefile b/Makefile
index 229d13b..6f980be 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -38,11 +38,15 @@ misc192_K1           = 17161514131211100f0e0d0c0b0a09080706050403020100
 misc256_K0              = 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f
 misc256_K1              = 1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100
 
+misc512_K0              = 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f
+misc512_K1              = 3f3e3d3c3b3a393837363534333231302f2e2d2c2b2a292827262524232221201f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100
+
 b64_N0                  = 554433221100
 b96_N0                  = 887766554433221100
 b128_N0                         = bbaa99887766554433221100
 b192_N0                         = 2110ffeeddccbbaa99887766554433221100
 b256_N0                         = 8776655443322110ffeeddccbbaa99887766554433221100
+b512_N0                         = aa9998887776665554443332221110000ffeeddccbbaa9988776655443322110ffeeddccbbaa99887766554433221100
 
 BLKC                   += des3
 des3_PRETTY             = 3DES
@@ -93,6 +97,14 @@ $(eval $(call def-lraes,128,128))
 $(eval $(call def-lraes,192,192))
 $(eval $(call def-lraes,256,256))
 
+BLKC                   += dlraes512
+dlraes512_PRETTY        = DLRAES512
+dlraes512_NAME          = dlraes512
+dlraes512_BLKSZ                 = 512
+dlraes512_K0            = $(misc256_K0)
+dlraes512_K1            = $(misc256_K1)
+dlraes512_KSZS          = $(aes_KSZS)
+
 BLKSZS                  = $(sort $(foreach c,$(BLKC),$($c_BLKSZ)))
 
 auto.mk: Makefile
@@ -190,14 +202,21 @@ lraes96_M0                 = 00112233445566778899aabb
 lraes128_M0             = 00112233445566778899aabbccddeeff
 lraes192_M0             = 00112233445566778899aabbccddeeff0112233445566778
 lraes256_M0             = 00112233445566778899aabbccddeeff0112233445566778899aabbccddeeff0
+lraes512_M0             = 00112233445566778899aabbccddeeff0112233445566778899aabbccddeeff00000111122223333444455556666777788889999aaaabbbbccccddddeeeeffff
 
 TARGETS                        += $(LRAESVERBOSE)
-LRAESVERBOSE            = $(foreach k,$(LRAES), lraes$k.verbose)
+LRAESVERBOSE            = $(foreach w,$(LRAES), lraes$w.verbose)
 $(LRAESVERBOSE): lraes%.verbose: ocbgen Makefile
        $(call v_tag,LRAES)./ocbgen >$@.new ocb3 rijndael lraes $$(( $*/8 )) \
                $(lraes$*_K0) $(lraes$*_M0)
        $(V_AT)mv $@.new $@
 
+TARGETS                        += dlraes512.verbose
+dlraes512.verbose: ocbgen Makefile
+       $(call v_tag,LRAES)./ocbgen >$@.new ocb3 lraes256 lraes 64 \
+               $(dlraes512_K0) $(lraes512_M0)
+       $(V_AT)mv $@.new $@
+
 all:: $(TARGETS)
 
 CLEAN                  += $(TARGETS)

diff --git a/find-stretch.sage b/find-stretch.sage
index cdd408b..61aef46 100644 (file)
--- a/find-stretch.sage
+++ b/find-stretch.sage
@@ -50,6 +50,6 @@ def stretch_shift(w):
     elif bits > best_bits: best_bits, best_dom, best_c = bits, d, c
   return best_c, best_dom
 
-for w in [64, 96, 128, 192, 256]:
+for w in [64, 96, 128, 192, 256, 512]:
   c, dom = stretch_shift(w)
   print '%3d: %3d [%d]' % (w, c, dom)

diff --git a/ocbgen b/ocbgen
index acdd997..a0c360f 100755 (executable)
--- a/ocbgen
+++ b/ocbgen
@@ -25,6 +25,7 @@
 from sys import argv, stderr
 from struct import pack
 from itertools import izip
+from contextlib import contextmanager
 import catacomb as C
 
 R = C.FibRand(0)
@@ -153,25 +154,35 @@ class LubyRackoffCipher (type):
     me.bc = bc
     return me
 
+@contextmanager
+def muffle():
+  global VERBOSE, LRVERBOSE
+  _v, _lrv = VERBOSE, LRVERBOSE
+  try:
+    VERBOSE = LRVERBOSE = False
+    yield None
+  finally:
+    VERBOSE, LRVERBOSE = _v, _lrv
+
 class LubyRackoffBase (object):
   NR = 4 # for strong-PRP security
   def __init__(me, k):
     if LRVERBOSE: print 'K = %s' % hex(k)
     bc, blksz = me.__class__.bc, me.__class__.blksz
-    E = bc(k)
+    with muffle(): E = bc(k)
     me.f = []
     ksz = len(k)
     i = C.MP(0)
     for j in xrange(me.NR):
       b = C.WriteBuffer()
       while b.size < ksz:
-        x = E.encrypt(i.storeb(bc.blksz))
+        with muffle(): x = E.encrypt(i.storeb(bc.blksz))
         b.put(x)
         if LRVERBOSE: print 'E(K; [%d]) = %s' % (i, hex(x))
         i += 1
       kj = C.ByteString(C.ByteString(b)[0:ksz])
       if LRVERBOSE: print 'K_%d = %s' % (j, hex(kj))
-      me.f.append(bc(kj))
+      with muffle(): me.f.append(bc(kj))
   def encrypt(me, m):
     bc, blksz = me.__class__.bc, me.__class__.blksz
     assert len(m) == blksz
@@ -179,7 +190,7 @@ class LubyRackoffBase (object):
     if LRVERBOSE: print 'L_0, R_0 = %s, %s' % (hex(l), hex(r))
     for j in xrange(me.NR):
       l0 = pad0star(l, bc.blksz)
-      t = me.f[j].encrypt(l0)
+      with muffle(): t = me.f[j].encrypt(l0)
       l, r = r ^ t[:blksz/2], l
       if LRVERBOSE:
         print 'E(K_%d; L_%d || 0^*) = %s' % (j, j, hex(t))
@@ -191,7 +202,7 @@ class LubyRackoffBase (object):
     l, r = C.ByteString(c[:blksz/2]), C.ByteString(c[blksz/2:])
     for j in xrange(me.NR - 1, -1, -1):
       l0 = pad0star(l, bc.blksz)
-      t = me.f[j].encrypt(l0)
+      with muffle(): t = me.f[j].encrypt(l0)
       if LRVERBOSE:
         print 'L_%d, R_%d = %s, %s' % (j + 1, j + 1, hex(l), hex(r))
         print 'E(K_%d; L_%d || 0^*) = %s' % (j + 1, j + 1, hex(t))
@@ -202,6 +213,7 @@ class LubyRackoffBase (object):
 LRAES = {}
 for i in [8, 12, 16, 24, 32]:
   LRAES['lraes%d' % (8*i)] = LubyRackoffCipher(C.rijndael, i)
+LRAES['dlraes512'] = LubyRackoffCipher(LubyRackoffCipher(C.rijndael, 32), 64)
 
 ###--------------------------------------------------------------------------
 ### PMAC.
@@ -386,7 +398,8 @@ OCB3_STRETCH = { 8: (5, 25),
                  12: (6, 33),
                  16: (6, 8),
                  24: (7, 40),
-                 32: (7, 120) }
+                 32: (7, 120),
+                 64: (8, 240) }
 
 def ocb3(E, n, h, m, tsz = None):
   blksz = E.__class__.blksz