1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
|
------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- G N A T . M D 5 --
-- --
-- B o d y --
-- --
-- Copyright (C) 2002-2008, AdaCore --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Ada.Unchecked_Conversion;
package body GNAT.MD5 is
use Interfaces;
Padding : constant String :=
(1 => Character'Val (16#80#), 2 .. 64 => ASCII.NUL);
Hex_Digit : constant array (Unsigned_32 range 0 .. 15) of Character :=
('0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f');
-- Look-up table for each hex digit of the Message-Digest.
-- Used by function Digest (Context).
-- The sixteen values used to rotate the context words.
-- Four for each rounds. Used in procedure Transform.
-- Round 1
S11 : constant := 7;
S12 : constant := 12;
S13 : constant := 17;
S14 : constant := 22;
-- Round 2
S21 : constant := 5;
S22 : constant := 9;
S23 : constant := 14;
S24 : constant := 20;
-- Round 3
S31 : constant := 4;
S32 : constant := 11;
S33 : constant := 16;
S34 : constant := 23;
-- Round 4
S41 : constant := 6;
S42 : constant := 10;
S43 : constant := 15;
S44 : constant := 21;
type Sixteen_Words is array (Natural range 0 .. 15)
of Interfaces.Unsigned_32;
-- Sixteen 32-bit words, converted from block of 64 characters.
-- Used in procedure Decode and Transform.
procedure Decode
(Block : String;
X : out Sixteen_Words);
-- Convert a String of 64 characters into 16 32-bit numbers
-- The following functions (F, FF, G, GG, H, HH, I and II) are the
-- equivalent of the macros of the same name in the example
-- C implementation in the annex of RFC 1321.
function F (X, Y, Z : Unsigned_32) return Unsigned_32;
pragma Inline (F);
procedure FF
(A : in out Unsigned_32;
B, C, D : Unsigned_32;
X : Unsigned_32;
AC : Unsigned_32;
S : Positive);
pragma Inline (FF);
function G (X, Y, Z : Unsigned_32) return Unsigned_32;
pragma Inline (G);
procedure GG
(A : in out Unsigned_32;
B, C, D : Unsigned_32;
X : Unsigned_32;
AC : Unsigned_32;
S : Positive);
pragma Inline (GG);
function H (X, Y, Z : Unsigned_32) return Unsigned_32;
pragma Inline (H);
procedure HH
(A : in out Unsigned_32;
B, C, D : Unsigned_32;
X : Unsigned_32;
AC : Unsigned_32;
S : Positive);
pragma Inline (HH);
function I (X, Y, Z : Unsigned_32) return Unsigned_32;
pragma Inline (I);
procedure II
(A : in out Unsigned_32;
B, C, D : Unsigned_32;
X : Unsigned_32;
AC : Unsigned_32;
S : Positive);
pragma Inline (II);
procedure Transform
(C : in out Context;
Block : String);
-- Process one block of 64 characters
------------
-- Decode --
------------
procedure Decode
(Block : String;
X : out Sixteen_Words)
is
Cur : Positive := Block'First;
begin
pragma Assert (Block'Length = 64);
for Index in X'Range loop
X (Index) :=
Unsigned_32 (Character'Pos (Block (Cur))) +
Shift_Left (Unsigned_32 (Character'Pos (Block (Cur + 1))), 8) +
Shift_Left (Unsigned_32 (Character'Pos (Block (Cur + 2))), 16) +
Shift_Left (Unsigned_32 (Character'Pos (Block (Cur + 3))), 24);
Cur := Cur + 4;
end loop;
end Decode;
------------
-- Digest --
------------
function Digest (C : Context) return Message_Digest is
Result : Message_Digest;
Cur : Natural := 1;
-- Index in Result where the next character will be placed
Last_Block : String (1 .. 64);
C1 : Context := C;
procedure Convert (X : Unsigned_32);
-- Put the contribution of one of the four words (A, B, C, D) of the
-- Context in Result. Increments Cur.
-------------
-- Convert --
-------------
procedure Convert (X : Unsigned_32) is
Y : Unsigned_32 := X;
begin
for J in 1 .. 4 loop
Result (Cur + 1) := Hex_Digit (Y and Unsigned_32'(16#0F#));
Y := Shift_Right (Y, 4);
Result (Cur) := Hex_Digit (Y and Unsigned_32'(16#0F#));
Y := Shift_Right (Y, 4);
Cur := Cur + 2;
end loop;
end Convert;
-- Start of processing for Digest
begin
-- Process characters in the context buffer, if any
Last_Block (1 .. C.Last) := C.Buffer (1 .. C.Last);
-- Too many magic literals below, should be defined as constants ???
if C.Last > 55 then
Last_Block (C.Last + 1 .. 64) := Padding (1 .. 64 - C.Last);
Transform (C1, Last_Block);
Last_Block := (others => ASCII.NUL);
else
Last_Block (C.Last + 1 .. 56) := Padding (1 .. 56 - C.Last);
end if;
-- Add the input length (as stored in the context) as 8 characters
Last_Block (57 .. 64) := (others => ASCII.NUL);
declare
L : Unsigned_64 := Unsigned_64 (C.Length) * 8;
Idx : Positive := 57;
begin
while L > 0 loop
Last_Block (Idx) := Character'Val (L and 16#Ff#);
L := Shift_Right (L, 8);
Idx := Idx + 1;
end loop;
end;
Transform (C1, Last_Block);
Convert (C1.A);
Convert (C1.B);
Convert (C1.C);
Convert (C1.D);
return Result;
end Digest;
function Digest (S : String) return Message_Digest is
C : Context;
begin
Update (C, S);
return Digest (C);
end Digest;
function Digest
(A : Ada.Streams.Stream_Element_Array) return Message_Digest
is
C : Context;
begin
Update (C, A);
return Digest (C);
end Digest;
-------
-- F --
-------
function F (X, Y, Z : Unsigned_32) return Unsigned_32 is
begin
return (X and Y) or ((not X) and Z);
end F;
--------
-- FF --
--------
procedure FF
(A : in out Unsigned_32;
B, C, D : Unsigned_32;
X : Unsigned_32;
AC : Unsigned_32;
S : Positive)
is
begin
A := A + F (B, C, D) + X + AC;
A := Rotate_Left (A, S);
A := A + B;
end FF;
-------
-- G --
-------
function G (X, Y, Z : Unsigned_32) return Unsigned_32 is
begin
return (X and Z) or (Y and (not Z));
end G;
--------
-- GG --
--------
procedure GG
(A : in out Unsigned_32;
B, C, D : Unsigned_32;
X : Unsigned_32;
AC : Unsigned_32;
S : Positive)
is
begin
A := A + G (B, C, D) + X + AC;
A := Rotate_Left (A, S);
A := A + B;
end GG;
-------
-- H --
-------
function H (X, Y, Z : Unsigned_32) return Unsigned_32 is
begin
return X xor Y xor Z;
end H;
--------
-- HH --
--------
procedure HH
(A : in out Unsigned_32;
B, C, D : Unsigned_32;
X : Unsigned_32;
AC : Unsigned_32;
S : Positive)
is
begin
A := A + H (B, C, D) + X + AC;
A := Rotate_Left (A, S);
A := A + B;
end HH;
-------
-- I --
-------
function I (X, Y, Z : Unsigned_32) return Unsigned_32 is
begin
return Y xor (X or (not Z));
end I;
--------
-- II --
--------
procedure II
(A : in out Unsigned_32;
B, C, D : Unsigned_32;
X : Unsigned_32;
AC : Unsigned_32;
S : Positive)
is
begin
A := A + I (B, C, D) + X + AC;
A := Rotate_Left (A, S);
A := A + B;
end II;
---------------
-- Transform --
---------------
procedure Transform
(C : in out Context;
Block : String)
is
X : Sixteen_Words;
AA : Unsigned_32 := C.A;
BB : Unsigned_32 := C.B;
CC : Unsigned_32 := C.C;
DD : Unsigned_32 := C.D;
begin
pragma Assert (Block'Length = 64);
Decode (Block, X);
-- Round 1
FF (AA, BB, CC, DD, X (00), 16#D76aa478#, S11); -- 1
FF (DD, AA, BB, CC, X (01), 16#E8c7b756#, S12); -- 2
FF (CC, DD, AA, BB, X (02), 16#242070db#, S13); -- 3
FF (BB, CC, DD, AA, X (03), 16#C1bdceee#, S14); -- 4
FF (AA, BB, CC, DD, X (04), 16#f57c0faf#, S11); -- 5
FF (DD, AA, BB, CC, X (05), 16#4787c62a#, S12); -- 6
FF (CC, DD, AA, BB, X (06), 16#a8304613#, S13); -- 7
FF (BB, CC, DD, AA, X (07), 16#fd469501#, S14); -- 8
FF (AA, BB, CC, DD, X (08), 16#698098d8#, S11); -- 9
FF (DD, AA, BB, CC, X (09), 16#8b44f7af#, S12); -- 10
FF (CC, DD, AA, BB, X (10), 16#ffff5bb1#, S13); -- 11
FF (BB, CC, DD, AA, X (11), 16#895cd7be#, S14); -- 12
FF (AA, BB, CC, DD, X (12), 16#6b901122#, S11); -- 13
FF (DD, AA, BB, CC, X (13), 16#fd987193#, S12); -- 14
FF (CC, DD, AA, BB, X (14), 16#a679438e#, S13); -- 15
FF (BB, CC, DD, AA, X (15), 16#49b40821#, S14); -- 16
-- Round 2
GG (AA, BB, CC, DD, X (01), 16#f61e2562#, S21); -- 17
GG (DD, AA, BB, CC, X (06), 16#c040b340#, S22); -- 18
GG (CC, DD, AA, BB, X (11), 16#265e5a51#, S23); -- 19
GG (BB, CC, DD, AA, X (00), 16#e9b6c7aa#, S24); -- 20
GG (AA, BB, CC, DD, X (05), 16#d62f105d#, S21); -- 21
GG (DD, AA, BB, CC, X (10), 16#02441453#, S22); -- 22
GG (CC, DD, AA, BB, X (15), 16#d8a1e681#, S23); -- 23
GG (BB, CC, DD, AA, X (04), 16#e7d3fbc8#, S24); -- 24
GG (AA, BB, CC, DD, X (09), 16#21e1cde6#, S21); -- 25
GG (DD, AA, BB, CC, X (14), 16#c33707d6#, S22); -- 26
GG (CC, DD, AA, BB, X (03), 16#f4d50d87#, S23); -- 27
GG (BB, CC, DD, AA, X (08), 16#455a14ed#, S24); -- 28
GG (AA, BB, CC, DD, X (13), 16#a9e3e905#, S21); -- 29
GG (DD, AA, BB, CC, X (02), 16#fcefa3f8#, S22); -- 30
GG (CC, DD, AA, BB, X (07), 16#676f02d9#, S23); -- 31
GG (BB, CC, DD, AA, X (12), 16#8d2a4c8a#, S24); -- 32
-- Round 3
HH (AA, BB, CC, DD, X (05), 16#fffa3942#, S31); -- 33
HH (DD, AA, BB, CC, X (08), 16#8771f681#, S32); -- 34
HH (CC, DD, AA, BB, X (11), 16#6d9d6122#, S33); -- 35
HH (BB, CC, DD, AA, X (14), 16#fde5380c#, S34); -- 36
HH (AA, BB, CC, DD, X (01), 16#a4beea44#, S31); -- 37
HH (DD, AA, BB, CC, X (04), 16#4bdecfa9#, S32); -- 38
HH (CC, DD, AA, BB, X (07), 16#f6bb4b60#, S33); -- 39
HH (BB, CC, DD, AA, X (10), 16#bebfbc70#, S34); -- 40
HH (AA, BB, CC, DD, X (13), 16#289b7ec6#, S31); -- 41
HH (DD, AA, BB, CC, X (00), 16#eaa127fa#, S32); -- 42
HH (CC, DD, AA, BB, X (03), 16#d4ef3085#, S33); -- 43
HH (BB, CC, DD, AA, X (06), 16#04881d05#, S34); -- 44
HH (AA, BB, CC, DD, X (09), 16#d9d4d039#, S31); -- 45
HH (DD, AA, BB, CC, X (12), 16#e6db99e5#, S32); -- 46
HH (CC, DD, AA, BB, X (15), 16#1fa27cf8#, S33); -- 47
HH (BB, CC, DD, AA, X (02), 16#c4ac5665#, S34); -- 48
-- Round 4
II (AA, BB, CC, DD, X (00), 16#f4292244#, S41); -- 49
II (DD, AA, BB, CC, X (07), 16#432aff97#, S42); -- 50
II (CC, DD, AA, BB, X (14), 16#ab9423a7#, S43); -- 51
II (BB, CC, DD, AA, X (05), 16#fc93a039#, S44); -- 52
II (AA, BB, CC, DD, X (12), 16#655b59c3#, S41); -- 53
II (DD, AA, BB, CC, X (03), 16#8f0ccc92#, S42); -- 54
II (CC, DD, AA, BB, X (10), 16#ffeff47d#, S43); -- 55
II (BB, CC, DD, AA, X (01), 16#85845dd1#, S44); -- 56
II (AA, BB, CC, DD, X (08), 16#6fa87e4f#, S41); -- 57
II (DD, AA, BB, CC, X (15), 16#fe2ce6e0#, S42); -- 58
II (CC, DD, AA, BB, X (06), 16#a3014314#, S43); -- 59
II (BB, CC, DD, AA, X (13), 16#4e0811a1#, S44); -- 60
II (AA, BB, CC, DD, X (04), 16#f7537e82#, S41); -- 61
II (DD, AA, BB, CC, X (11), 16#bd3af235#, S42); -- 62
II (CC, DD, AA, BB, X (02), 16#2ad7d2bb#, S43); -- 63
II (BB, CC, DD, AA, X (09), 16#eb86d391#, S44); -- 64
C.A := C.A + AA;
C.B := C.B + BB;
C.C := C.C + CC;
C.D := C.D + DD;
end Transform;
------------
-- Update --
------------
procedure Update
(C : in out Context;
Input : String)
is
Inp : constant String := C.Buffer (1 .. C.Last) & Input;
Cur : Positive := Inp'First;
begin
C.Length := C.Length + Input'Length;
while Cur + 63 <= Inp'Last loop
Transform (C, Inp (Cur .. Cur + 63));
Cur := Cur + 64;
end loop;
C.Last := Inp'Last - Cur + 1;
C.Buffer (1 .. C.Last) := Inp (Cur .. Inp'Last);
end Update;
procedure Update
(C : in out Context;
Input : Ada.Streams.Stream_Element_Array)
is
subtype Stream_Array is Ada.Streams.Stream_Element_Array (Input'Range);
subtype Stream_String is
String (1 + Integer (Input'First) .. 1 + Integer (Input'Last));
function To_String is new Ada.Unchecked_Conversion
(Stream_Array, Stream_String);
String_Input : constant String := To_String (Input);
begin
Update (C, String_Input);
end Update;
-----------------
-- Wide_Digest --
-----------------
function Wide_Digest (W : Wide_String) return Message_Digest is
C : Context;
begin
Wide_Update (C, W);
return Digest (C);
end Wide_Digest;
-----------------
-- Wide_Update --
-----------------
procedure Wide_Update
(C : in out Context;
Input : Wide_String)
is
String_Input : String (1 .. 2 * Input'Length);
Cur : Positive := 1;
begin
for Index in Input'Range loop
String_Input (Cur) :=
Character'Val
(Unsigned_32 (Wide_Character'Pos (Input (Index))) and 16#FF#);
Cur := Cur + 1;
String_Input (Cur) :=
Character'Val
(Shift_Right (Unsigned_32 (Wide_Character'Pos (Input (Index))), 8)
and 16#FF#);
Cur := Cur + 1;
end loop;
Update (C, String_Input);
end Wide_Update;
end GNAT.MD5;
|
