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ea054059 MW |
1 | #! /usr/bin/python |
2 | ||
3 | from sys import argv | |
4 | from struct import pack | |
5 | from itertools import izip | |
6 | import catacomb as C | |
7 | ||
8 | R = C.FibRand(0) | |
9 | ||
10 | ###-------------------------------------------------------------------------- | |
11 | ### Utilities. | |
12 | ||
13 | def combs(things, k): | |
14 | ii = range(k) | |
15 | n = len(things) | |
16 | while True: | |
17 | yield [things[i] for i in ii] | |
18 | for j in xrange(k): | |
19 | if j == k - 1: lim = n | |
20 | else: lim = ii[j + 1] | |
21 | i = ii[j] + 1 | |
22 | if i < lim: | |
23 | ii[j] = i | |
24 | break | |
25 | ii[j] = j | |
26 | else: | |
27 | return | |
28 | ||
29 | POLYMAP = {} | |
30 | ||
31 | def poly(nbits): | |
32 | try: return POLYMAP[nbits] | |
33 | except KeyError: pass | |
34 | base = C.GF(0).setbit(nbits).setbit(0) | |
35 | for k in xrange(1, nbits, 2): | |
36 | for cc in combs(range(1, nbits), k): | |
37 | p = base + sum(C.GF(0).setbit(c) for c in cc) | |
38 | if p.irreduciblep(): POLYMAP[nbits] = p; return p | |
39 | raise ValueError, nbits | |
40 | ||
41 | def Z(n): | |
42 | return C.ByteString.zero(n) | |
43 | ||
44 | def mul_blk_gf(m, x, p): return ((C.GF.loadb(m)*x)%p).storeb((p.nbits + 6)/8) | |
45 | ||
46 | def with_lastp(it): | |
47 | it = iter(it) | |
48 | try: j = next(it) | |
49 | except StopIteration: raise ValueError, 'empty iter' | |
50 | lastp = False | |
51 | while not lastp: | |
52 | i = j | |
53 | try: j = next(it) | |
54 | except StopIteration: lastp = True | |
55 | yield i, lastp | |
56 | ||
57 | def safehex(x): | |
58 | if len(x): return hex(x) | |
59 | else: return '""' | |
60 | ||
61 | def keylens(ksz): | |
62 | sel = [] | |
63 | if isinstance(ksz, C.KeySZSet): kk = ksz.set | |
64 | elif isinstance(ksz, C.KeySZRange): kk = range(ksz.min, ksz.max, ksz.mod) | |
65 | elif isinstance(ksz, C.KeySZAny): kk = range(64); sel = [0] | |
66 | kk = list(kk); kk = kk[:] | |
67 | n = len(kk) | |
68 | while n and len(sel) < 4: | |
69 | i = R.range(n) | |
70 | n -= 1 | |
71 | kk[i], kk[n] = kk[n], kk[i] | |
72 | sel.append(kk[n]) | |
73 | return sel | |
74 | ||
75 | def pad0star(m, w): | |
76 | n = len(m) | |
77 | if not n: r = w | |
78 | else: r = (-len(m))%w | |
79 | if r: m += Z(r) | |
80 | return C.ByteString(m) | |
81 | ||
82 | def pad10star(m, w): | |
83 | r = w - len(m)%w | |
84 | if r: m += '\x80' + Z(r - 1) | |
85 | return C.ByteString(m) | |
86 | ||
87 | def ntz(i): | |
88 | j = 0 | |
89 | while (i&1) == 0: i >>= 1; j += 1 | |
90 | return j | |
91 | ||
92 | def blocks(x, w): | |
93 | v, i, n = [], 0, len(x) | |
94 | while n - i > w: | |
95 | v.append(C.ByteString(x[i:i + w])) | |
96 | i += w | |
97 | return v, C.ByteString(x[i:]) | |
98 | ||
99 | EMPTY = C.bytes('') | |
100 | ||
101 | def blocks0(x, w): | |
102 | v, tl = blocks(x, w) | |
103 | if len(tl) == w: v.append(tl); tl = EMPTY | |
104 | return v, tl | |
105 | ||
2964c388 MW |
106 | def dummygen(bc): return [] |
107 | ||
ea054059 MW |
108 | CUSTOM = {} |
109 | ||
110 | ###-------------------------------------------------------------------------- | |
111 | ### RC6. | |
112 | ||
113 | class RC6Cipher (type): | |
114 | def __new__(cls, w, r): | |
115 | name = 'rc6-%d/%d' % (w, r) | |
116 | me = type(name, (RC6Base,), {}) | |
117 | me.name = name | |
118 | me.r = r | |
119 | me.w = w | |
120 | me.blksz = w/2 | |
121 | me.keysz = C.KeySZRange(me.blksz, 1, 255, 1) | |
122 | return me | |
123 | ||
124 | def rotw(w): | |
125 | return w.bit_length() - 1 | |
126 | ||
127 | def rol(w, x, n): | |
128 | m0, m1 = C.MP(0).setbit(w - n) - 1, C.MP(0).setbit(n) - 1 | |
129 | return ((x&m0) << n) | (x >> (w - n))&m1 | |
130 | ||
131 | def ror(w, x, n): | |
132 | m0, m1 = C.MP(0).setbit(n) - 1, C.MP(0).setbit(w - n) - 1 | |
133 | return ((x&m0) << (w - n)) | (x >> n)&m1 | |
134 | ||
135 | class RC6Base (object): | |
136 | ||
137 | ## Magic constants. | |
138 | P400 = C.MP(0xb7e151628aed2a6abf7158809cf4f3c762e7160f38b4da56a784d9045190cfef324e7738926cfbe5f4bf8d8d8c31d763da06) | |
139 | Q400 = C.MP(0x9e3779b97f4a7c15f39cc0605cedc8341082276bf3a27251f86c6a11d0c18e952767f0b153d27b7f0347045b5bf1827f0188) | |
140 | ||
141 | def __init__(me, k): | |
142 | ||
143 | ## Build the magic numbers. | |
144 | P = me.P400 >> (400 - me.w) | |
145 | if P%2 == 0: P += 1 | |
146 | Q = me.Q400 >> (400 - me.w) | |
147 | if Q%2 == 0: Q += 1 | |
148 | M = C.MP(0).setbit(me.w) - 1 | |
149 | ||
150 | ## Convert the key into words. | |
151 | wb = me.w/8 | |
152 | c = (len(k) + wb - 1)/wb | |
153 | kb, ktl = blocks(k, me.w/8) | |
154 | L = map(C.MP.loadl, kb + [ktl]) | |
155 | assert c == len(L) | |
156 | ||
157 | ## Build the subkey table. | |
158 | me.d = rotw(me.w) | |
159 | n = 2*me.r + 4 | |
160 | S = [(P + i*Q)&M for i in xrange(n)] | |
161 | ||
162 | ##for j in xrange(c): | |
163 | ## print 'L[%3d] = %s' % (j, hex(L[j]).upper()[2:].rjust(2*wb, '0')) | |
164 | ##for i in xrange(n): | |
165 | ## print 'S[%3d] = %s' % (i, hex(S[i]).upper()[2:].rjust(2*wb, '0')) | |
166 | ||
167 | i = j = 0 | |
168 | A = B = C.MP(0) | |
169 | ||
170 | for s in xrange(3*max(c, n)): | |
171 | A = S[i] = rol(me.w, S[i] + A + B, 3) | |
172 | B = L[j] = rol(me.w, L[j] + A + B, (A + B)%(1 << me.d)) | |
173 | ##print 'S[%3d] = %s' % (i, hex(S[i]).upper()[2:].rjust(2*wb, '0')) | |
174 | ##print 'L[%3d] = %s' % (j, hex(L[j]).upper()[2:].rjust(2*wb, '0')) | |
175 | i = (i + 1)%n | |
176 | j = (j + 1)%c | |
177 | ||
178 | ## Done. | |
179 | me.s = S | |
180 | ||
181 | def encrypt(me, x): | |
182 | M = C.MP(0).setbit(me.w) - 1 | |
183 | a, b, c, d = map(C.MP.loadl, blocks0(x, me.blksz/4)[0]) | |
184 | b = (b + me.s[0])&M | |
185 | d = (d + me.s[1])&M | |
186 | ##print 'B = %s' % (hex(b).upper()[2:].rjust(me.w/4, '0')) | |
187 | ##print 'D = %s' % (hex(d).upper()[2:].rjust(me.w/4, '0')) | |
188 | for i in xrange(2, 2*me.r + 2, 2): | |
189 | t = rol(me.w, 2*b*b + b, me.d) | |
190 | u = rol(me.w, 2*d*d + d, me.d) | |
191 | a = (rol(me.w, a ^ t, u%(1 << me.d)) + me.s[i + 0])&M | |
192 | c = (rol(me.w, c ^ u, t%(1 << me.d)) + me.s[i + 1])&M | |
193 | ##print 'A = %s' % (hex(a).upper()[2:].rjust(me.w/4, '0')) | |
194 | ##print 'C = %s' % (hex(c).upper()[2:].rjust(me.w/4, '0')) | |
195 | a, b, c, d = b, c, d, a | |
196 | a = (a + me.s[2*me.r + 2])&M | |
197 | c = (c + me.s[2*me.r + 3])&M | |
198 | ##print 'A = %s' % (hex(a).upper()[2:].rjust(me.w/4, '0')) | |
199 | ##print 'C = %s' % (hex(c).upper()[2:].rjust(me.w/4, '0')) | |
200 | return C.ByteString(a.storel(me.blksz/4) + b.storel(me.blksz/4) + | |
201 | c.storel(me.blksz/4) + d.storel(me.blksz/4)) | |
202 | ||
203 | def decrypt(me, x): | |
204 | M = C.MP(0).setbit(me.w) - 1 | |
205 | a, b, c, d = map(C.MP.loadl, blocks0(x, me.blksz/4)) | |
206 | c = (c - me.s[2*me.r + 3])&M | |
207 | a = (a - me.s[2*me.r + 2])&M | |
208 | for i in xrange(2*me.r + 1, 1, -2): | |
209 | a, b, c, d = d, a, b, c | |
210 | u = rol(me.w, 2*d*d + d, me.d) | |
211 | t = rol(me.w, 2*b*b + b, me.d) | |
212 | c = ror(me.w, (c - me.s[i + 1])&M, t%(1 << me.d)) ^ u | |
213 | a = ror(me.w, (a - me.s[i + 0])&M, u%(1 << me.d)) ^ t | |
214 | a = (a + s[2*me.r + 2])&M | |
215 | c = (c + s[2*me.r + 3])&M | |
216 | return C.ByteString(a.storel(me.blksz/4) + b.storel(me.blksz/4) + | |
217 | c.storel(me.blksz/4) + d.storel(me.blksz/4)) | |
218 | ||
219 | for (w, r) in [(8, 16), (16, 16), (24, 16), (32, 16), | |
220 | (32, 20), (48, 16), (64, 16), (96, 16), (128, 16), | |
221 | (192, 16), (256, 16), (400, 16)]: | |
222 | CUSTOM['rc6-%d/%d' % (w, r)] = RC6Cipher(w, r) | |
223 | ||
224 | ###-------------------------------------------------------------------------- | |
225 | ### OMAC (or CMAC). | |
226 | ||
227 | def omac_masks(E): | |
228 | blksz = E.__class__.blksz | |
229 | p = poly(8*blksz) | |
230 | z = Z(blksz) | |
231 | L = E.encrypt(z) | |
232 | m0 = mul_blk_gf(L, 2, p) | |
233 | m1 = mul_blk_gf(m0, 2, p) | |
234 | return m0, m1 | |
235 | ||
236 | def dump_omac(E): | |
237 | blksz = E.__class__.blksz | |
238 | m0, m1 = omac_masks(E) | |
239 | print 'L = %s' % hex(E.encrypt(Z(blksz))) | |
240 | print 'm0 = %s' % hex(m0) | |
241 | print 'm1 = %s' % hex(m1) | |
242 | for t in xrange(3): | |
243 | print 'v%d = %s' % (t, hex(E.encrypt(C.MP(t).storeb(blksz)))) | |
244 | print 'z%d = %s' % (t, hex(omac(E, t, ''))) | |
245 | ||
246 | def omac(E, t, m): | |
247 | blksz = E.__class__.blksz | |
248 | m0, m1 = omac_masks(E) | |
249 | a = Z(blksz) | |
250 | if t is not None: m = C.MP(t).storeb(blksz) + m | |
251 | v, tl = blocks(m, blksz) | |
252 | for x in v: a = E.encrypt(a ^ x) | |
253 | r = blksz - len(tl) | |
254 | if r == 0: | |
255 | a = E.encrypt(a ^ tl ^ m0) | |
256 | else: | |
257 | pad = pad10star(tl, blksz) | |
258 | a = E.encrypt(a ^ pad ^ m1) | |
259 | return a | |
260 | ||
261 | def cmac(E, m): | |
262 | if VERBOSE: dump_omac(E) | |
263 | return omac(E, None, m), | |
264 | ||
265 | def cmacgen(bc): | |
266 | return [(0,), (1,), | |
267 | (3*bc.blksz,), | |
268 | (3*bc.blksz - 5,)] | |
269 | ||
2964c388 MW |
270 | ###-------------------------------------------------------------------------- |
271 | ### Counter mode. | |
272 | ||
273 | def ctr(E, m, c0): | |
274 | blksz = E.__class__.blksz | |
275 | y = C.WriteBuffer() | |
276 | c = C.MP.loadb(c0) | |
277 | while y.size < len(m): | |
278 | y.put(E.encrypt(c.storeb(blksz))) | |
279 | c += 1 | |
280 | return C.ByteString(m) ^ C.ByteString(y)[:len(m)] | |
281 | ||
282 | ###-------------------------------------------------------------------------- | |
283 | ### EAX. | |
284 | ||
285 | def eaxenc(E, n, h, m, tsz = None): | |
286 | if VERBOSE: | |
287 | print 'k = %s' % hex(k) | |
288 | print 'n = %s' % hex(n) | |
289 | print 'h = %s' % hex(h) | |
290 | print 'm = %s' % hex(m) | |
291 | dump_omac(E) | |
292 | if tsz is None: tsz = E.__class__.blksz | |
293 | c0 = omac(E, 0, n) | |
294 | y = ctr(E, m, c0) | |
295 | ht = omac(E, 1, h) | |
296 | yt = omac(E, 2, y) | |
297 | if VERBOSE: | |
298 | print 'c0 = %s' % hex(c0) | |
299 | print 'ht = %s' % hex(ht) | |
300 | print 'yt = %s' % hex(yt) | |
301 | return y, C.ByteString((c0 ^ ht ^ yt)[:tsz]) | |
302 | ||
303 | def eaxdec(E, n, h, y, t): | |
304 | if VERBOSE: | |
305 | print 'k = %s' % hex(k) | |
306 | print 'n = %s' % hex(n) | |
307 | print 'h = %s' % hex(h) | |
308 | print 'y = %s' % hex(y) | |
309 | print 't = %s' % hex(t) | |
310 | dump_omac(E) | |
311 | c0 = omac(E, 0, n) | |
312 | m = ctr(E, y, c0) | |
313 | ht = omac(E, 1, h) | |
314 | yt = omac(E, 2, y) | |
315 | if VERBOSE: | |
316 | print 'c0 = %s' % hex(c0) | |
317 | print 'ht = %s' % hex(ht) | |
318 | print 'yt = %s' % hex(yt) | |
319 | if t == (c0 ^ ht ^ yt)[:len(t)]: return m, | |
320 | else: return None, | |
321 | ||
322 | def eaxgen(bc): | |
323 | return [(0, 0, 0), (1, 0, 0), (0, 1, 0), (0, 0, 1), | |
324 | (bc.blksz, 3*bc.blksz, 3*bc.blksz), | |
325 | (bc.blksz - 1, 3*bc.blksz - 5, 3*bc.blksz + 5)] | |
326 | ||
ea054059 MW |
327 | ###-------------------------------------------------------------------------- |
328 | ### Main program. | |
329 | ||
330 | class struct (object): | |
331 | def __init__(me, **kw): | |
332 | me.__dict__.update(kw) | |
333 | ||
334 | binarg = struct(mk = R.block, parse = C.bytes, show = safehex) | |
335 | intarg = struct(mk = lambda x: x, parse = int, show = None) | |
336 | ||
2964c388 MW |
337 | MODEMAP = { 'eax-enc': (eaxgen, 3*[binarg] + [intarg], eaxenc), |
338 | 'eax-dec': (dummygen, 4*[binarg], eaxdec), | |
339 | 'cmac': (cmacgen, [binarg], cmac) } | |
ea054059 MW |
340 | |
341 | mode = argv[1] | |
342 | bc = None | |
343 | for d in CUSTOM, C.gcprps: | |
344 | try: bc = d[argv[2]] | |
345 | except KeyError: pass | |
346 | else: break | |
347 | if bc is None: raise KeyError, argv[2] | |
348 | if len(argv) == 3: | |
349 | VERBOSE = False | |
350 | gen, argty, func = MODEMAP[mode] | |
2964c388 | 351 | if mode.endswith('-enc'): mode = mode[:-4] |
ea054059 MW |
352 | print '%s-%s {' % (bc.name, mode) |
353 | for ksz in keylens(bc.keysz): | |
354 | for argvals in gen(bc): | |
355 | k = R.block(ksz) | |
356 | args = [t.mk(a) for t, a in izip(argty, argvals)] | |
357 | rets = func(bc(k), *args) | |
358 | print ' %s' % safehex(k) | |
359 | for t, a in izip(argty, args): | |
360 | if t.show: print ' %s' % t.show(a) | |
361 | for r, lastp in with_lastp(rets): | |
362 | print ' %s%s' % (safehex(r), lastp and ';' or '') | |
363 | print '}' | |
364 | else: | |
365 | VERBOSE = True | |
366 | k = C.bytes(argv[3]) | |
367 | gen, argty, func = MODEMAP[mode] | |
368 | args = [t.parse(a) for t, a in izip(argty, argv[4:])] | |
369 | rets = func(bc(k), *args) | |
2964c388 MW |
370 | for r in rets: |
371 | if r is None: print "X" | |
372 | else: print hex(r) | |
ea054059 MW |
373 | |
374 | ###----- That's all, folks -------------------------------------------------- |