1%%
2%% %CopyrightBegin%
3%%
4%% Copyright Ericsson AB 2008-2016. All Rights Reserved.
5%%
6%% Licensed under the Apache License, Version 2.0 (the "License");
7%% you may not use this file except in compliance with the License.
8%% You may obtain a copy of the License at
9%%
10%%     http://www.apache.org/licenses/LICENSE-2.0
11%%
12%% Unless required by applicable law or agreed to in writing, software
13%% distributed under the License is distributed on an "AS IS" BASIS,
14%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15%% See the License for the specific language governing permissions and
16%% limitations under the License.
17%%
18%% %CopyrightEnd%
19%%
20
21%%
22%% Reference implementations of crc32, adler32 and md5 in erlang. Used
23%% by crypto_SUITE.
24%%
25
26-module(crypto_reference).
27
28-export([adler32/1, crc32/1, md5_init/0, md5_update/2, md5_final/1]).
29-export([crc32_table/0, reflect8_table/0]).
30
31-define(BASE, 65521).
32-define(NMAX, 5552).
33
34-define(AINIT,<<0,0,0,1>>).
35
36adler32(Bin) when is_binary(Bin) ->
37    B2 = adler32(Bin,0,1),
38    <<Sum:32/big>> = B2,
39    Sum;
40
41adler32(IoList) ->
42    adler32(erlang:iolist_to_binary(IoList)).
43
44adler32(<<>>,B,A) ->
45    <<B:16/big,A:16/big>>;
46
47adler32(<<CH:8,T/binary>>,B,A) ->
48    NewA = (A+CH) rem ?BASE,
49    NewB = (B+NewA) rem ?BASE,
50    adler32(T,NewB,NewA).
51
52-define(FINAL_XOR_VALUE,16#FFFFFFFF).
53-define(INITIAL_REMAINDER,16#FFFFFFFF).
54
55reflect_bin(<<>>,Res) ->
56    Res;
57reflect_bin(<<X:1,Rest/bitstring>>,BS) ->
58    reflect_bin(Rest,<<X:1,BS/bitstring>>).
59reflect(Data,8) ->
60    reflect8(Data);
61reflect(Data,32) ->
62    <<A:8,B:8,C:8,D:8>> = <<Data:32>>,
63    ND = reflect8(D),
64    NC = reflect8(C),
65    NB = reflect8(B),
66    NA = reflect8(A),
67    <<Result:32>> = <<ND:8,NC:8,NB:8,NA:8>>,
68    Result;
69reflect(Data,Size) ->
70    <<NewData:Size>> = reflect_bin(<<Data:Size>>,<<>>),
71    NewData.
72crc32(<<>>,Remainder) ->
73    reflect(Remainder,32) bxor ?FINAL_XOR_VALUE;
74crc32(<<CH:8,T/binary>>,Remainder) ->
75    Data = reflect(CH,8) bxor (Remainder bsr 24),
76    NewRem = crcTab32(Data) bxor ((Remainder bsl 8) band 16#FFFFFFFF),
77%    io:format("CH = ~p (~p)~n",[CH,reflect(CH,8)]),
78%    io:format("No reflect = ~p~n",[(CH bxor (Remainder bsr 24))]),
79%    io:format("Data = ~p, NewRem = ~p~n",[Data,NewRem]),
80    crc32(T,NewRem).
81
82crc32(Bin) when is_binary(Bin) ->
83    crc32(Bin,?INITIAL_REMAINDER);
84crc32(L) ->
85    crc32(erlang:iolist_to_binary(L)).
86
87bitmod2(0,Remainder,_Topbit,_Polynomial,_Mask) ->
88    %io:format("~p ",[Remainder]),
89    Remainder;
90bitmod2(N,Remainder,Topbit,Polynomial,Mask) ->
91    %io:format("~p ",[Remainder]),
92    case (Remainder band Topbit) of
93	0 ->
94	    bitmod2(N-1,(Remainder bsl 1) band Mask,Topbit,Polynomial,Mask);
95	_ ->
96	    bitmod2(N-1,((Remainder bsl 1) bxor Polynomial) band Mask,Topbit,Polynomial,Mask)
97    end.
98
99mask(CrcSize) ->
100    16#FFFFFFFF bsr (32 - CrcSize).
101
102calc_crc_table(256,_CrcSize,_Polynomial) ->
103    ok;
104calc_crc_table(Dividend,CrcSize,Polynomial) ->
105    Mask = mask(CrcSize),
106    Remainder = (Dividend bsl (CrcSize - 8)) band Mask,
107    TopBit = 1 bsl (CrcSize - 1),
108    Rem2 = bitmod2(8,Remainder,TopBit,Polynomial,Mask),
109    io:format("crcTab~p(~p) -> ~p;~n",[CrcSize,Dividend,Rem2]),
110    calc_crc_table(Dividend+1,CrcSize,Polynomial).
111
112crc32_table() ->
113   calc_crc_table(0,32,16#04C11DB7).
114
115reflect8_table(256) ->
116    ok;
117reflect8_table(N) ->
118    X = reflect(N,8),
119    io:format("reflect8(~p) -> ~p;~n",[N,X]),
120    reflect8_table(N+1).
121reflect8_table() ->
122    reflect8_table(0).
123
124%CRC32 table calculated with crc32_table above
125crcTab32(0) -> 0;
126crcTab32(1) -> 79764919;
127crcTab32(2) -> 159529838;
128crcTab32(3) -> 222504665;
129crcTab32(4) -> 319059676;
130crcTab32(5) -> 398814059;
131crcTab32(6) -> 445009330;
132crcTab32(7) -> 507990021;
133crcTab32(8) -> 638119352;
134crcTab32(9) -> 583659535;
135crcTab32(10) -> 797628118;
136crcTab32(11) -> 726387553;
137crcTab32(12) -> 890018660;
138crcTab32(13) -> 835552979;
139crcTab32(14) -> 1015980042;
140crcTab32(15) -> 944750013;
141crcTab32(16) -> 1276238704;
142crcTab32(17) -> 1221641927;
143crcTab32(18) -> 1167319070;
144crcTab32(19) -> 1095957929;
145crcTab32(20) -> 1595256236;
146crcTab32(21) -> 1540665371;
147crcTab32(22) -> 1452775106;
148crcTab32(23) -> 1381403509;
149crcTab32(24) -> 1780037320;
150crcTab32(25) -> 1859660671;
151crcTab32(26) -> 1671105958;
152crcTab32(27) -> 1733955601;
153crcTab32(28) -> 2031960084;
154crcTab32(29) -> 2111593891;
155crcTab32(30) -> 1889500026;
156crcTab32(31) -> 1952343757;
157crcTab32(32) -> 2552477408;
158crcTab32(33) -> 2632100695;
159crcTab32(34) -> 2443283854;
160crcTab32(35) -> 2506133561;
161crcTab32(36) -> 2334638140;
162crcTab32(37) -> 2414271883;
163crcTab32(38) -> 2191915858;
164crcTab32(39) -> 2254759653;
165crcTab32(40) -> 3190512472;
166crcTab32(41) -> 3135915759;
167crcTab32(42) -> 3081330742;
168crcTab32(43) -> 3009969537;
169crcTab32(44) -> 2905550212;
170crcTab32(45) -> 2850959411;
171crcTab32(46) -> 2762807018;
172crcTab32(47) -> 2691435357;
173crcTab32(48) -> 3560074640;
174crcTab32(49) -> 3505614887;
175crcTab32(50) -> 3719321342;
176crcTab32(51) -> 3648080713;
177crcTab32(52) -> 3342211916;
178crcTab32(53) -> 3287746299;
179crcTab32(54) -> 3467911202;
180crcTab32(55) -> 3396681109;
181crcTab32(56) -> 4063920168;
182crcTab32(57) -> 4143685023;
183crcTab32(58) -> 4223187782;
184crcTab32(59) -> 4286162673;
185crcTab32(60) -> 3779000052;
186crcTab32(61) -> 3858754371;
187crcTab32(62) -> 3904687514;
188crcTab32(63) -> 3967668269;
189crcTab32(64) -> 881225847;
190crcTab32(65) -> 809987520;
191crcTab32(66) -> 1023691545;
192crcTab32(67) -> 969234094;
193crcTab32(68) -> 662832811;
194crcTab32(69) -> 591600412;
195crcTab32(70) -> 771767749;
196crcTab32(71) -> 717299826;
197crcTab32(72) -> 311336399;
198crcTab32(73) -> 374308984;
199crcTab32(74) -> 453813921;
200crcTab32(75) -> 533576470;
201crcTab32(76) -> 25881363;
202crcTab32(77) -> 88864420;
203crcTab32(78) -> 134795389;
204crcTab32(79) -> 214552010;
205crcTab32(80) -> 2023205639;
206crcTab32(81) -> 2086057648;
207crcTab32(82) -> 1897238633;
208crcTab32(83) -> 1976864222;
209crcTab32(84) -> 1804852699;
210crcTab32(85) -> 1867694188;
211crcTab32(86) -> 1645340341;
212crcTab32(87) -> 1724971778;
213crcTab32(88) -> 1587496639;
214crcTab32(89) -> 1516133128;
215crcTab32(90) -> 1461550545;
216crcTab32(91) -> 1406951526;
217crcTab32(92) -> 1302016099;
218crcTab32(93) -> 1230646740;
219crcTab32(94) -> 1142491917;
220crcTab32(95) -> 1087903418;
221crcTab32(96) -> 2896545431;
222crcTab32(97) -> 2825181984;
223crcTab32(98) -> 2770861561;
224crcTab32(99) -> 2716262478;
225crcTab32(100) -> 3215044683;
226crcTab32(101) -> 3143675388;
227crcTab32(102) -> 3055782693;
228crcTab32(103) -> 3001194130;
229crcTab32(104) -> 2326604591;
230crcTab32(105) -> 2389456536;
231crcTab32(106) -> 2200899649;
232crcTab32(107) -> 2280525302;
233crcTab32(108) -> 2578013683;
234crcTab32(109) -> 2640855108;
235crcTab32(110) -> 2418763421;
236crcTab32(111) -> 2498394922;
237crcTab32(112) -> 3769900519;
238crcTab32(113) -> 3832873040;
239crcTab32(114) -> 3912640137;
240crcTab32(115) -> 3992402750;
241crcTab32(116) -> 4088425275;
242crcTab32(117) -> 4151408268;
243crcTab32(118) -> 4197601365;
244crcTab32(119) -> 4277358050;
245crcTab32(120) -> 3334271071;
246crcTab32(121) -> 3263032808;
247crcTab32(122) -> 3476998961;
248crcTab32(123) -> 3422541446;
249crcTab32(124) -> 3585640067;
250crcTab32(125) -> 3514407732;
251crcTab32(126) -> 3694837229;
252crcTab32(127) -> 3640369242;
253crcTab32(128) -> 1762451694;
254crcTab32(129) -> 1842216281;
255crcTab32(130) -> 1619975040;
256crcTab32(131) -> 1682949687;
257crcTab32(132) -> 2047383090;
258crcTab32(133) -> 2127137669;
259crcTab32(134) -> 1938468188;
260crcTab32(135) -> 2001449195;
261crcTab32(136) -> 1325665622;
262crcTab32(137) -> 1271206113;
263crcTab32(138) -> 1183200824;
264crcTab32(139) -> 1111960463;
265crcTab32(140) -> 1543535498;
266crcTab32(141) -> 1489069629;
267crcTab32(142) -> 1434599652;
268crcTab32(143) -> 1363369299;
269crcTab32(144) -> 622672798;
270crcTab32(145) -> 568075817;
271crcTab32(146) -> 748617968;
272crcTab32(147) -> 677256519;
273crcTab32(148) -> 907627842;
274crcTab32(149) -> 853037301;
275crcTab32(150) -> 1067152940;
276crcTab32(151) -> 995781531;
277crcTab32(152) -> 51762726;
278crcTab32(153) -> 131386257;
279crcTab32(154) -> 177728840;
280crcTab32(155) -> 240578815;
281crcTab32(156) -> 269590778;
282crcTab32(157) -> 349224269;
283crcTab32(158) -> 429104020;
284crcTab32(159) -> 491947555;
285crcTab32(160) -> 4046411278;
286crcTab32(161) -> 4126034873;
287crcTab32(162) -> 4172115296;
288crcTab32(163) -> 4234965207;
289crcTab32(164) -> 3794477266;
290crcTab32(165) -> 3874110821;
291crcTab32(166) -> 3953728444;
292crcTab32(167) -> 4016571915;
293crcTab32(168) -> 3609705398;
294crcTab32(169) -> 3555108353;
295crcTab32(170) -> 3735388376;
296crcTab32(171) -> 3664026991;
297crcTab32(172) -> 3290680682;
298crcTab32(173) -> 3236090077;
299crcTab32(174) -> 3449943556;
300crcTab32(175) -> 3378572211;
301crcTab32(176) -> 3174993278;
302crcTab32(177) -> 3120533705;
303crcTab32(178) -> 3032266256;
304crcTab32(179) -> 2961025959;
305crcTab32(180) -> 2923101090;
306crcTab32(181) -> 2868635157;
307crcTab32(182) -> 2813903052;
308crcTab32(183) -> 2742672763;
309crcTab32(184) -> 2604032198;
310crcTab32(185) -> 2683796849;
311crcTab32(186) -> 2461293480;
312crcTab32(187) -> 2524268063;
313crcTab32(188) -> 2284983834;
314crcTab32(189) -> 2364738477;
315crcTab32(190) -> 2175806836;
316crcTab32(191) -> 2238787779;
317crcTab32(192) -> 1569362073;
318crcTab32(193) -> 1498123566;
319crcTab32(194) -> 1409854455;
320crcTab32(195) -> 1355396672;
321crcTab32(196) -> 1317987909;
322crcTab32(197) -> 1246755826;
323crcTab32(198) -> 1192025387;
324crcTab32(199) -> 1137557660;
325crcTab32(200) -> 2072149281;
326crcTab32(201) -> 2135122070;
327crcTab32(202) -> 1912620623;
328crcTab32(203) -> 1992383480;
329crcTab32(204) -> 1753615357;
330crcTab32(205) -> 1816598090;
331crcTab32(206) -> 1627664531;
332crcTab32(207) -> 1707420964;
333crcTab32(208) -> 295390185;
334crcTab32(209) -> 358241886;
335crcTab32(210) -> 404320391;
336crcTab32(211) -> 483945776;
337crcTab32(212) -> 43990325;
338crcTab32(213) -> 106832002;
339crcTab32(214) -> 186451547;
340crcTab32(215) -> 266083308;
341crcTab32(216) -> 932423249;
342crcTab32(217) -> 861060070;
343crcTab32(218) -> 1041341759;
344crcTab32(219) -> 986742920;
345crcTab32(220) -> 613929101;
346crcTab32(221) -> 542559546;
347crcTab32(222) -> 756411363;
348crcTab32(223) -> 701822548;
349crcTab32(224) -> 3316196985;
350crcTab32(225) -> 3244833742;
351crcTab32(226) -> 3425377559;
352crcTab32(227) -> 3370778784;
353crcTab32(228) -> 3601682597;
354crcTab32(229) -> 3530312978;
355crcTab32(230) -> 3744426955;
356crcTab32(231) -> 3689838204;
357crcTab32(232) -> 3819031489;
358crcTab32(233) -> 3881883254;
359crcTab32(234) -> 3928223919;
360crcTab32(235) -> 4007849240;
361crcTab32(236) -> 4037393693;
362crcTab32(237) -> 4100235434;
363crcTab32(238) -> 4180117107;
364crcTab32(239) -> 4259748804;
365crcTab32(240) -> 2310601993;
366crcTab32(241) -> 2373574846;
367crcTab32(242) -> 2151335527;
368crcTab32(243) -> 2231098320;
369crcTab32(244) -> 2596047829;
370crcTab32(245) -> 2659030626;
371crcTab32(246) -> 2470359227;
372crcTab32(247) -> 2550115596;
373crcTab32(248) -> 2947551409;
374crcTab32(249) -> 2876312838;
375crcTab32(250) -> 2788305887;
376crcTab32(251) -> 2733848168;
377crcTab32(252) -> 3165939309;
378crcTab32(253) -> 3094707162;
379crcTab32(254) -> 3040238851;
380crcTab32(255) -> 2985771188;
381crcTab32(_) -> exit(not_a_byte).
382
383%%
384%% Reflect8 table generated with code above crcTab32
385%%
386
387reflect8(0) -> 0;
388reflect8(1) -> 128;
389reflect8(2) -> 64;
390reflect8(3) -> 192;
391reflect8(4) -> 32;
392reflect8(5) -> 160;
393reflect8(6) -> 96;
394reflect8(7) -> 224;
395reflect8(8) -> 16;
396reflect8(9) -> 144;
397reflect8(10) -> 80;
398reflect8(11) -> 208;
399reflect8(12) -> 48;
400reflect8(13) -> 176;
401reflect8(14) -> 112;
402reflect8(15) -> 240;
403reflect8(16) -> 8;
404reflect8(17) -> 136;
405reflect8(18) -> 72;
406reflect8(19) -> 200;
407reflect8(20) -> 40;
408reflect8(21) -> 168;
409reflect8(22) -> 104;
410reflect8(23) -> 232;
411reflect8(24) -> 24;
412reflect8(25) -> 152;
413reflect8(26) -> 88;
414reflect8(27) -> 216;
415reflect8(28) -> 56;
416reflect8(29) -> 184;
417reflect8(30) -> 120;
418reflect8(31) -> 248;
419reflect8(32) -> 4;
420reflect8(33) -> 132;
421reflect8(34) -> 68;
422reflect8(35) -> 196;
423reflect8(36) -> 36;
424reflect8(37) -> 164;
425reflect8(38) -> 100;
426reflect8(39) -> 228;
427reflect8(40) -> 20;
428reflect8(41) -> 148;
429reflect8(42) -> 84;
430reflect8(43) -> 212;
431reflect8(44) -> 52;
432reflect8(45) -> 180;
433reflect8(46) -> 116;
434reflect8(47) -> 244;
435reflect8(48) -> 12;
436reflect8(49) -> 140;
437reflect8(50) -> 76;
438reflect8(51) -> 204;
439reflect8(52) -> 44;
440reflect8(53) -> 172;
441reflect8(54) -> 108;
442reflect8(55) -> 236;
443reflect8(56) -> 28;
444reflect8(57) -> 156;
445reflect8(58) -> 92;
446reflect8(59) -> 220;
447reflect8(60) -> 60;
448reflect8(61) -> 188;
449reflect8(62) -> 124;
450reflect8(63) -> 252;
451reflect8(64) -> 2;
452reflect8(65) -> 130;
453reflect8(66) -> 66;
454reflect8(67) -> 194;
455reflect8(68) -> 34;
456reflect8(69) -> 162;
457reflect8(70) -> 98;
458reflect8(71) -> 226;
459reflect8(72) -> 18;
460reflect8(73) -> 146;
461reflect8(74) -> 82;
462reflect8(75) -> 210;
463reflect8(76) -> 50;
464reflect8(77) -> 178;
465reflect8(78) -> 114;
466reflect8(79) -> 242;
467reflect8(80) -> 10;
468reflect8(81) -> 138;
469reflect8(82) -> 74;
470reflect8(83) -> 202;
471reflect8(84) -> 42;
472reflect8(85) -> 170;
473reflect8(86) -> 106;
474reflect8(87) -> 234;
475reflect8(88) -> 26;
476reflect8(89) -> 154;
477reflect8(90) -> 90;
478reflect8(91) -> 218;
479reflect8(92) -> 58;
480reflect8(93) -> 186;
481reflect8(94) -> 122;
482reflect8(95) -> 250;
483reflect8(96) -> 6;
484reflect8(97) -> 134;
485reflect8(98) -> 70;
486reflect8(99) -> 198;
487reflect8(100) -> 38;
488reflect8(101) -> 166;
489reflect8(102) -> 102;
490reflect8(103) -> 230;
491reflect8(104) -> 22;
492reflect8(105) -> 150;
493reflect8(106) -> 86;
494reflect8(107) -> 214;
495reflect8(108) -> 54;
496reflect8(109) -> 182;
497reflect8(110) -> 118;
498reflect8(111) -> 246;
499reflect8(112) -> 14;
500reflect8(113) -> 142;
501reflect8(114) -> 78;
502reflect8(115) -> 206;
503reflect8(116) -> 46;
504reflect8(117) -> 174;
505reflect8(118) -> 110;
506reflect8(119) -> 238;
507reflect8(120) -> 30;
508reflect8(121) -> 158;
509reflect8(122) -> 94;
510reflect8(123) -> 222;
511reflect8(124) -> 62;
512reflect8(125) -> 190;
513reflect8(126) -> 126;
514reflect8(127) -> 254;
515reflect8(128) -> 1;
516reflect8(129) -> 129;
517reflect8(130) -> 65;
518reflect8(131) -> 193;
519reflect8(132) -> 33;
520reflect8(133) -> 161;
521reflect8(134) -> 97;
522reflect8(135) -> 225;
523reflect8(136) -> 17;
524reflect8(137) -> 145;
525reflect8(138) -> 81;
526reflect8(139) -> 209;
527reflect8(140) -> 49;
528reflect8(141) -> 177;
529reflect8(142) -> 113;
530reflect8(143) -> 241;
531reflect8(144) -> 9;
532reflect8(145) -> 137;
533reflect8(146) -> 73;
534reflect8(147) -> 201;
535reflect8(148) -> 41;
536reflect8(149) -> 169;
537reflect8(150) -> 105;
538reflect8(151) -> 233;
539reflect8(152) -> 25;
540reflect8(153) -> 153;
541reflect8(154) -> 89;
542reflect8(155) -> 217;
543reflect8(156) -> 57;
544reflect8(157) -> 185;
545reflect8(158) -> 121;
546reflect8(159) -> 249;
547reflect8(160) -> 5;
548reflect8(161) -> 133;
549reflect8(162) -> 69;
550reflect8(163) -> 197;
551reflect8(164) -> 37;
552reflect8(165) -> 165;
553reflect8(166) -> 101;
554reflect8(167) -> 229;
555reflect8(168) -> 21;
556reflect8(169) -> 149;
557reflect8(170) -> 85;
558reflect8(171) -> 213;
559reflect8(172) -> 53;
560reflect8(173) -> 181;
561reflect8(174) -> 117;
562reflect8(175) -> 245;
563reflect8(176) -> 13;
564reflect8(177) -> 141;
565reflect8(178) -> 77;
566reflect8(179) -> 205;
567reflect8(180) -> 45;
568reflect8(181) -> 173;
569reflect8(182) -> 109;
570reflect8(183) -> 237;
571reflect8(184) -> 29;
572reflect8(185) -> 157;
573reflect8(186) -> 93;
574reflect8(187) -> 221;
575reflect8(188) -> 61;
576reflect8(189) -> 189;
577reflect8(190) -> 125;
578reflect8(191) -> 253;
579reflect8(192) -> 3;
580reflect8(193) -> 131;
581reflect8(194) -> 67;
582reflect8(195) -> 195;
583reflect8(196) -> 35;
584reflect8(197) -> 163;
585reflect8(198) -> 99;
586reflect8(199) -> 227;
587reflect8(200) -> 19;
588reflect8(201) -> 147;
589reflect8(202) -> 83;
590reflect8(203) -> 211;
591reflect8(204) -> 51;
592reflect8(205) -> 179;
593reflect8(206) -> 115;
594reflect8(207) -> 243;
595reflect8(208) -> 11;
596reflect8(209) -> 139;
597reflect8(210) -> 75;
598reflect8(211) -> 203;
599reflect8(212) -> 43;
600reflect8(213) -> 171;
601reflect8(214) -> 107;
602reflect8(215) -> 235;
603reflect8(216) -> 27;
604reflect8(217) -> 155;
605reflect8(218) -> 91;
606reflect8(219) -> 219;
607reflect8(220) -> 59;
608reflect8(221) -> 187;
609reflect8(222) -> 123;
610reflect8(223) -> 251;
611reflect8(224) -> 7;
612reflect8(225) -> 135;
613reflect8(226) -> 71;
614reflect8(227) -> 199;
615reflect8(228) -> 39;
616reflect8(229) -> 167;
617reflect8(230) -> 103;
618reflect8(231) -> 231;
619reflect8(232) -> 23;
620reflect8(233) -> 151;
621reflect8(234) -> 87;
622reflect8(235) -> 215;
623reflect8(236) -> 55;
624reflect8(237) -> 183;
625reflect8(238) -> 119;
626reflect8(239) -> 247;
627reflect8(240) -> 15;
628reflect8(241) -> 143;
629reflect8(242) -> 79;
630reflect8(243) -> 207;
631reflect8(244) -> 47;
632reflect8(245) -> 175;
633reflect8(246) -> 111;
634reflect8(247) -> 239;
635reflect8(248) -> 31;
636reflect8(249) -> 159;
637reflect8(250) -> 95;
638reflect8(251) -> 223;
639reflect8(252) -> 63;
640reflect8(253) -> 191;
641reflect8(254) -> 127;
642reflect8(255) -> 255;
643reflect8(_) -> exit(not_a_byte).
644
645%%%
646%%% Old MD5 implementation by Tony, modified to fit testing
647%%%
648
649-record(md5_ctx,
650	{
651	 state = { 16#67452301, 16#efcdab89, 16#98badcfe, 16#10325476 },
652	 count = 0,    %% number of bits (64 bit)
653	 buffer = <<>>    %% input buffer (16 bytes)
654	}).
655
656-define(S11, 7).
657-define(S12, 12).
658-define(S13, 17).
659-define(S14, 22).
660-define(S21, 5).
661-define(S22, 9).
662-define(S23, 14).
663-define(S24, 20).
664-define(S31, 4).
665-define(S32, 11).
666-define(S33, 16).
667-define(S34, 23).
668-define(S41, 6).
669-define(S42, 10).
670-define(S43, 15).
671-define(S44, 21).
672
673%% F, G, H and I are basic MD5 functions.
674
675-define(F(X, Y, Z), (((X) band (Y)) bor ((bnot (X)) band (Z)))).
676-define(G(X, Y, Z), (((X) band (Z)) bor ((Y) band (bnot (Z))))).
677-define(H(X, Y, Z), ((X) bxor (Y) bxor (Z))).
678-define(I(X, Y, Z), ((Y) bxor ((X) bor (bnot (Z))))).
679
680-define(U32(X), ((X) band 16#ffffffff)).
681
682-define(ROTATE_LEFT(X,N), rotate_left(X,N)).
683
684%% FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
685%% Rotation is separate from addition to prevent recomputation.
686%%
687-define(FF(A, B, C, D, X, S, AC),
688	?ROTATE_LEFT(A + ?F((B), (C), (D)) + (X) + (AC),(S)) + (B)).
689
690-define(GG(A, B, C, D, X, S, AC),
691	?ROTATE_LEFT(A + ?G((B), (C), (D)) + (X) + (AC),(S)) + (B)).
692
693-define( HH(A, B, C, D, X, S, AC),
694	?ROTATE_LEFT(A + ?H((B), (C), (D)) + (X) + (AC),(S)) + (B)).
695
696-define(II(A, B, C, D, X, S, AC),
697	?ROTATE_LEFT(A +  ?I((B), (C), (D)) + (X) + (AC),(S)) + (B)).
698
699md5_init() ->
700    #md5_ctx {}.
701
702md5_update(CTX, Input) when is_list(Input) ->
703    md5_update(CTX,iolist_to_binary(Input));
704md5_update(CTX, Input) when is_binary(Input) ->
705    Buffer = CTX#md5_ctx.buffer,
706    LenI = size(Input),
707    Len = LenI + size(Buffer),
708    md5_update(<<Buffer/binary,Input/binary>>, Len,CTX#md5_ctx.state,
709	   CTX#md5_ctx.count+(LenI bsl 3)).
710
711%%
712%% update state, count reflects number of bytes
713%% including bytes in buffer
714%%
715md5_update(Buf0, Len0, State0, Count) when Len0 >= 64 ->
716    {Xs,Buf1} = decode(Buf0, 64),
717    State1 = transform(State0, Xs),
718    md5_update(Buf1, Len0 - 64, State1, Count);
719md5_update(Buf0, _Len0, State0, Count) ->
720    #md5_ctx { state = State0, count = Count, buffer = Buf0 }.
721
722%% produce a digest
723md5_final(CTX) ->
724    %% pad out to a length 56 (we later add a count that makes 64)
725    Count = CTX#md5_ctx.count,      %% number of bits
726    Index =  (Count bsr 3) rem 64,  %% number of bytes
727    PadLen = if Index < 56 ->
728		     56 - Index;
729		true -> 120 - Index
730	     end,
731    CTX1 = md5_update(CTX, list_to_binary(padding(PadLen,[]))),
732    CTX2 = md5_update(CTX1, list_to_binary(encode([?U32(Count), ?U32(Count bsr 32)]))),
733    list_to_binary(encode(tuple_to_list(CTX2#md5_ctx.state))).
734
735%% generate padding info to final
736padding(0,Acc) -> Acc;
737padding(1,Acc) -> [16#80 | Acc];
738padding(N,Acc) -> padding(N-1, [0 | Acc]).
739
740%% rotate X as 32-bit unsigned left N bits
741rotate_left(X, N) ->
742    ?U32(X bsl N) bor (?U32(X) bsr (32 - N)).
743
744%%
745%% decodes Len number of bytes into 32 bit integers
746%% returns {Xs, Tail}
747%%
748decode(Buf, Len) ->
749    decode(Buf, Len, []).
750
751decode(Buf, 0, Acc) ->
752    {lists:reverse(Acc), Buf};
753decode(<<A:32/little,Buf/binary>>, N, Acc) ->
754    decode(Buf, N-4, [ A | Acc]).
755
756%%
757%% Encodes input 32-bit ints into byte buffer output.
758%%
759encode(Xs) -> encode(Xs, []).
760
761encode([X | Xs], Acc) ->
762    encode(Xs, [(X bsr 24) band 16#ff,
763		(X bsr 16) band 16#ff,
764		(X bsr 8) band 16#ff,
765		X  band 16#ff | Acc]);
766encode([], Acc) -> lists:reverse(Acc).
767
768
769transform({A0,B0,C0,D0}, Xs) ->
770    [X0,X1,X2,X3,X4,X5,X6,X7,X8,X9,X10,X11,X12,X13,X14,X15] = Xs,
771
772    %% Round 1
773    A1 = ?FF (A0, B0, C0, D0, X0, ?S11, 16#d76aa478),
774    D1 = ?FF (D0, A1, B0, C0, X1, ?S12, 16#e8c7b756),
775    C1 = ?FF (C0, D1, A1, B0, X2, ?S13, 16#242070db),
776    B1 = ?FF (B0, C1, D1, A1, X3, ?S14, 16#c1bdceee),
777
778    A2 = ?FF (A1, B1, C1, D1, X4, ?S11, 16#f57c0faf),
779    D2 = ?FF (D1, A2, B1, C1, X5, ?S12, 16#4787c62a),
780    C2 = ?FF (C1, D2, A2, B1, X6, ?S13, 16#a8304613),
781    B2 = ?FF (B1, C2, D2, A2, X7, ?S14, 16#fd469501),
782
783    A3 = ?FF (A2, B2, C2, D2, X8, ?S11, 16#698098d8),
784    D3 = ?FF (D2, A3, B2, C2, X9, ?S12, 16#8b44f7af),
785    C3 = ?FF (C2, D3, A3, B2, X10, ?S13, 16#ffff5bb1),
786    B3 = ?FF (B2, C3, D3, A3, X11, ?S14, 16#895cd7be),
787
788    A4 = ?FF (A3, B3, C3, D3, X12, ?S11, 16#6b901122),
789    D4 = ?FF (D3, A4, B3, C3, X13, ?S12, 16#fd987193),
790    C4 = ?FF (C3, D4, A4, B3, X14, ?S13, 16#a679438e),
791    B4 = ?FF (B3, C4, D4, A4, X15, ?S14, 16#49b40821),
792
793    %% Round 2
794    A5 = ?GG (A4, B4, C4, D4, X1, ?S21, 16#f61e2562),
795    D5 = ?GG (D4, A5, B4, C4, X6, ?S22, 16#c040b340),
796    C5 = ?GG (C4, D5, A5, B4, X11, ?S23, 16#265e5a51),
797    B5 = ?GG (B4, C5, D5, A5, X0, ?S24, 16#e9b6c7aa),
798
799    A6 = ?GG (A5, B5, C5, D5, X5, ?S21, 16#d62f105d),
800    D6 = ?GG (D5, A6, B5, C5, X10, ?S22,  16#2441453),
801    C6 = ?GG (C5, D6, A6, B5, X15, ?S23, 16#d8a1e681),
802    B6 = ?GG (B5, C6, D6, A6, X4, ?S24, 16#e7d3fbc8),
803
804    A7 = ?GG (A6, B6, C6, D6, X9, ?S21, 16#21e1cde6),
805    D7 = ?GG (D6, A7, B6, C6, X14, ?S22, 16#c33707d6),
806    C7 = ?GG (C6, D7, A7, B6, X3, ?S23, 16#f4d50d87),
807    B7 = ?GG (B6, C7, D7, A7, X8, ?S24, 16#455a14ed),
808
809    A8 = ?GG (A7, B7, C7, D7, X13, ?S21, 16#a9e3e905),
810    D8 = ?GG (D7, A8, B7, C7, X2, ?S22, 16#fcefa3f8),
811    C8 = ?GG (C7, D8, A8, B7, X7, ?S23, 16#676f02d9),
812    B8 = ?GG (B7, C8, D8, A8, X12, ?S24, 16#8d2a4c8a),
813
814 %% Round 3
815    A9 = ?HH (A8, B8, C8, D8, X5, ?S31, 16#fffa3942),
816    D9 = ?HH (D8, A9, B8, C8, X8, ?S32, 16#8771f681),
817    C9 = ?HH (C8, D9, A9, B8, X11, ?S33, 16#6d9d6122),
818    B9 = ?HH (B8, C9, D9, A9, X14, ?S34, 16#fde5380c),
819
820    A10 = ?HH (A9, B9, C9, D9, X1, ?S31, 16#a4beea44),
821    D10 = ?HH (D9, A10, B9, C9, X4, ?S32, 16#4bdecfa9),
822    C10 = ?HH (C9, D10, A10, B9, X7, ?S33, 16#f6bb4b60),
823    B10 = ?HH (B9, C10, D10, A10, X10, ?S34, 16#bebfbc70),
824
825    A11 = ?HH (A10, B10, C10, D10, X13, ?S31, 16#289b7ec6),
826    D11 = ?HH (D10, A11, B10, C10, X0, ?S32, 16#eaa127fa),
827    C11 = ?HH (C10, D11, A11, B10, X3, ?S33, 16#d4ef3085),
828    B11 = ?HH (B10, C11, D11, A11, X6, ?S34,  16#4881d05),
829
830    A12 = ?HH (A11, B11, C11, D11, X9, ?S31, 16#d9d4d039),
831    D12 = ?HH (D11, A12, B11, C11, X12, ?S32, 16#e6db99e5),
832    C12 = ?HH (C11, D12, A12, B11, X15, ?S33, 16#1fa27cf8),
833    B12 = ?HH (B11, C12, D12, A12, X2, ?S34, 16#c4ac5665),
834
835 %% Round 4
836    A13 = ?II (A12, B12, C12, D12, X0, ?S41, 16#f4292244),
837    D13 = ?II (D12, A13, B12, C12, X7, ?S42, 16#432aff97),
838    C13 = ?II (C12, D13, A13, B12, X14, ?S43, 16#ab9423a7),
839    B13 = ?II (B12, C13, D13, A13, X5, ?S44, 16#fc93a039),
840
841    A14 = ?II (A13, B13, C13, D13, X12, ?S41, 16#655b59c3),
842    D14 = ?II (D13, A14, B13, C13, X3, ?S42, 16#8f0ccc92),
843    C14 = ?II (C13, D14, A14, B13, X10, ?S43, 16#ffeff47d),
844    B14 = ?II (B13, C14, D14, A14, X1, ?S44, 16#85845dd1),
845
846    A15 = ?II (A14, B14, C14, D14, X8, ?S41, 16#6fa87e4f),
847    D15 = ?II (D14, A15, B14, C14, X15, ?S42, 16#fe2ce6e0),
848    C15 = ?II (C14, D15, A15, B14, X6, ?S43, 16#a3014314),
849    B15 = ?II (B14, C15, D15, A15, X13, ?S44, 16#4e0811a1),
850
851    A16 = ?II (A15, B15, C15, D15, X4, ?S41, 16#f7537e82),
852    D16 = ?II (D15, A16, B15, C15, X11, ?S42, 16#bd3af235),
853    C16 = ?II (C15, D16, A16, B15, X2, ?S43, 16#2ad7d2bb),
854    B16 = ?II (B15, C16, D16, A16, X9, ?S44, 16#eb86d391),
855
856    {?U32(A0+A16), ?U32(B0+B16), ?U32(C0+C16), ?U32(D0+D16)}.
857
858