1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT LIBRARY COMPONENTS                          --
4--                                                                          --
5--               G N A T . S E C U R E _ H A S H E S . M D 5                --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--         Copyright (C) 2002-2009, Free Software Foundation, Inc.          --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32with GNAT.Byte_Swapping; use GNAT.Byte_Swapping;
33
34package body GNAT.Secure_Hashes.MD5 is
35
36   use Interfaces;
37
38   --  The sixteen values used to rotate the context words. Four for each
39   --  rounds. Used in procedure Transform.
40
41   --  Round 1
42
43   S11 : constant := 7;
44   S12 : constant := 12;
45   S13 : constant := 17;
46   S14 : constant := 22;
47
48   --  Round 2
49
50   S21 : constant := 5;
51   S22 : constant := 9;
52   S23 : constant := 14;
53   S24 : constant := 20;
54
55   --  Round 3
56
57   S31 : constant := 4;
58   S32 : constant := 11;
59   S33 : constant := 16;
60   S34 : constant := 23;
61
62   --  Round 4
63
64   S41 : constant := 6;
65   S42 : constant := 10;
66   S43 : constant := 15;
67   S44 : constant := 21;
68
69   --  The following functions (F, FF, G, GG, H, HH, I and II) are the
70   --  equivalent of the macros of the same name in the example C
71   --  implementation in the annex of RFC 1321.
72
73   function F (X, Y, Z : Unsigned_32) return Unsigned_32;
74   pragma Inline (F);
75
76   procedure FF
77     (A       : in out Unsigned_32;
78      B, C, D : Unsigned_32;
79      X       : Unsigned_32;
80      AC      : Unsigned_32;
81      S       : Positive);
82   pragma Inline (FF);
83
84   function G (X, Y, Z : Unsigned_32) return Unsigned_32;
85   pragma Inline (G);
86
87   procedure GG
88     (A       : in out Unsigned_32;
89      B, C, D : Unsigned_32;
90      X       : Unsigned_32;
91      AC      : Unsigned_32;
92      S       : Positive);
93   pragma Inline (GG);
94
95   function H (X, Y, Z : Unsigned_32) return Unsigned_32;
96   pragma Inline (H);
97
98   procedure HH
99     (A       : in out Unsigned_32;
100      B, C, D : Unsigned_32;
101      X       : Unsigned_32;
102      AC      : Unsigned_32;
103      S       : Positive);
104   pragma Inline (HH);
105
106   function I (X, Y, Z : Unsigned_32) return Unsigned_32;
107   pragma Inline (I);
108
109   procedure II
110     (A       : in out Unsigned_32;
111      B, C, D : Unsigned_32;
112      X       : Unsigned_32;
113      AC      : Unsigned_32;
114      S       : Positive);
115   pragma Inline (II);
116
117   -------
118   -- F --
119   -------
120
121   function F (X, Y, Z : Unsigned_32) return Unsigned_32 is
122   begin
123      return (X and Y) or ((not X) and Z);
124   end F;
125
126   --------
127   -- FF --
128   --------
129
130   procedure FF
131     (A       : in out Unsigned_32;
132      B, C, D : Unsigned_32;
133      X       : Unsigned_32;
134      AC      : Unsigned_32;
135      S       : Positive)
136   is
137   begin
138      A := A + F (B, C, D) + X + AC;
139      A := Rotate_Left (A, S);
140      A := A + B;
141   end FF;
142
143   -------
144   -- G --
145   -------
146
147   function G (X, Y, Z : Unsigned_32) return Unsigned_32 is
148   begin
149      return (X and Z) or (Y and (not Z));
150   end G;
151
152   --------
153   -- GG --
154   --------
155
156   procedure GG
157     (A       : in out Unsigned_32;
158      B, C, D : Unsigned_32;
159      X       : Unsigned_32;
160      AC      : Unsigned_32;
161      S       : Positive)
162   is
163   begin
164      A := A + G (B, C, D) + X + AC;
165      A := Rotate_Left (A, S);
166      A := A + B;
167   end GG;
168
169   -------
170   -- H --
171   -------
172
173   function H (X, Y, Z : Unsigned_32) return Unsigned_32 is
174   begin
175      return X xor Y xor Z;
176   end H;
177
178   --------
179   -- HH --
180   --------
181
182   procedure HH
183     (A       : in out Unsigned_32;
184      B, C, D : Unsigned_32;
185      X       : Unsigned_32;
186      AC      : Unsigned_32;
187      S       : Positive)
188   is
189   begin
190      A := A + H (B, C, D) + X + AC;
191      A := Rotate_Left (A, S);
192      A := A + B;
193   end HH;
194
195   -------
196   -- I --
197   -------
198
199   function I (X, Y, Z : Unsigned_32) return Unsigned_32 is
200   begin
201      return Y xor (X or (not Z));
202   end I;
203
204   --------
205   -- II --
206   --------
207
208   procedure II
209     (A       : in out Unsigned_32;
210      B, C, D : Unsigned_32;
211      X       : Unsigned_32;
212      AC      : Unsigned_32;
213      S       : Positive)
214   is
215   begin
216      A := A + I (B, C, D) + X + AC;
217      A := Rotate_Left (A, S);
218      A := A + B;
219   end II;
220
221   ---------------
222   -- Transform --
223   ---------------
224
225   procedure Transform
226     (H : in out Hash_State.State;
227      M : in out Message_State)
228   is
229      use System;
230
231      X : array (0 .. 15) of Interfaces.Unsigned_32;
232      for X'Address use M.Buffer'Address;
233      pragma Import (Ada, X);
234
235      AA : Unsigned_32 := H (0);
236      BB : Unsigned_32 := H (1);
237      CC : Unsigned_32 := H (2);
238      DD : Unsigned_32 := H (3);
239
240   begin
241      if Default_Bit_Order /= Low_Order_First then
242         for J in X'Range loop
243            Swap4 (X (J)'Address);
244         end loop;
245      end if;
246
247      --  Round 1
248
249      FF (AA, BB, CC, DD, X (00), 16#D76aa478#, S11); --  1
250      FF (DD, AA, BB, CC, X (01), 16#E8c7b756#, S12); --  2
251      FF (CC, DD, AA, BB, X (02), 16#242070db#, S13); --  3
252      FF (BB, CC, DD, AA, X (03), 16#C1bdceee#, S14); --  4
253
254      FF (AA, BB, CC, DD, X (04), 16#f57c0faf#, S11); --  5
255      FF (DD, AA, BB, CC, X (05), 16#4787c62a#, S12); --  6
256      FF (CC, DD, AA, BB, X (06), 16#a8304613#, S13); --  7
257      FF (BB, CC, DD, AA, X (07), 16#fd469501#, S14); --  8
258
259      FF (AA, BB, CC, DD, X (08), 16#698098d8#, S11); --  9
260      FF (DD, AA, BB, CC, X (09), 16#8b44f7af#, S12); --  10
261      FF (CC, DD, AA, BB, X (10), 16#ffff5bb1#, S13); --  11
262      FF (BB, CC, DD, AA, X (11), 16#895cd7be#, S14); --  12
263
264      FF (AA, BB, CC, DD, X (12), 16#6b901122#, S11); --  13
265      FF (DD, AA, BB, CC, X (13), 16#fd987193#, S12); --  14
266      FF (CC, DD, AA, BB, X (14), 16#a679438e#, S13); --  15
267      FF (BB, CC, DD, AA, X (15), 16#49b40821#, S14); --  16
268
269      --  Round 2
270
271      GG (AA, BB, CC, DD, X (01), 16#f61e2562#, S21); --  17
272      GG (DD, AA, BB, CC, X (06), 16#c040b340#, S22); --  18
273      GG (CC, DD, AA, BB, X (11), 16#265e5a51#, S23); --  19
274      GG (BB, CC, DD, AA, X (00), 16#e9b6c7aa#, S24); --  20
275
276      GG (AA, BB, CC, DD, X (05), 16#d62f105d#, S21); --  21
277      GG (DD, AA, BB, CC, X (10), 16#02441453#, S22); --  22
278      GG (CC, DD, AA, BB, X (15), 16#d8a1e681#, S23); --  23
279      GG (BB, CC, DD, AA, X (04), 16#e7d3fbc8#, S24); --  24
280
281      GG (AA, BB, CC, DD, X (09), 16#21e1cde6#, S21); --  25
282      GG (DD, AA, BB, CC, X (14), 16#c33707d6#, S22); --  26
283      GG (CC, DD, AA, BB, X (03), 16#f4d50d87#, S23); --  27
284      GG (BB, CC, DD, AA, X (08), 16#455a14ed#, S24); --  28
285
286      GG (AA, BB, CC, DD, X (13), 16#a9e3e905#, S21); --  29
287      GG (DD, AA, BB, CC, X (02), 16#fcefa3f8#, S22); --  30
288      GG (CC, DD, AA, BB, X (07), 16#676f02d9#, S23); --  31
289      GG (BB, CC, DD, AA, X (12), 16#8d2a4c8a#, S24); --  32
290
291      --  Round 3
292
293      HH (AA, BB, CC, DD, X (05), 16#fffa3942#, S31); --  33
294      HH (DD, AA, BB, CC, X (08), 16#8771f681#, S32); --  34
295      HH (CC, DD, AA, BB, X (11), 16#6d9d6122#, S33); --  35
296      HH (BB, CC, DD, AA, X (14), 16#fde5380c#, S34); --  36
297
298      HH (AA, BB, CC, DD, X (01), 16#a4beea44#, S31); --  37
299      HH (DD, AA, BB, CC, X (04), 16#4bdecfa9#, S32); --  38
300      HH (CC, DD, AA, BB, X (07), 16#f6bb4b60#, S33); --  39
301      HH (BB, CC, DD, AA, X (10), 16#bebfbc70#, S34); --  40
302
303      HH (AA, BB, CC, DD, X (13), 16#289b7ec6#, S31); --  41
304      HH (DD, AA, BB, CC, X (00), 16#eaa127fa#, S32); --  42
305      HH (CC, DD, AA, BB, X (03), 16#d4ef3085#, S33); --  43
306      HH (BB, CC, DD, AA, X (06), 16#04881d05#, S34); --  44
307
308      HH (AA, BB, CC, DD, X (09), 16#d9d4d039#, S31); --  45
309      HH (DD, AA, BB, CC, X (12), 16#e6db99e5#, S32); --  46
310      HH (CC, DD, AA, BB, X (15), 16#1fa27cf8#, S33); --  47
311      HH (BB, CC, DD, AA, X (02), 16#c4ac5665#, S34); --  48
312
313      --  Round 4
314
315      II (AA, BB, CC, DD, X (00), 16#f4292244#, S41); --  49
316      II (DD, AA, BB, CC, X (07), 16#432aff97#, S42); --  50
317      II (CC, DD, AA, BB, X (14), 16#ab9423a7#, S43); --  51
318      II (BB, CC, DD, AA, X (05), 16#fc93a039#, S44); --  52
319
320      II (AA, BB, CC, DD, X (12), 16#655b59c3#, S41); --  53
321      II (DD, AA, BB, CC, X (03), 16#8f0ccc92#, S42); --  54
322      II (CC, DD, AA, BB, X (10), 16#ffeff47d#, S43); --  55
323      II (BB, CC, DD, AA, X (01), 16#85845dd1#, S44); --  56
324
325      II (AA, BB, CC, DD, X (08), 16#6fa87e4f#, S41); --  57
326      II (DD, AA, BB, CC, X (15), 16#fe2ce6e0#, S42); --  58
327      II (CC, DD, AA, BB, X (06), 16#a3014314#, S43); --  59
328      II (BB, CC, DD, AA, X (13), 16#4e0811a1#, S44); --  60
329
330      II (AA, BB, CC, DD, X (04), 16#f7537e82#, S41); --  61
331      II (DD, AA, BB, CC, X (11), 16#bd3af235#, S42); --  62
332      II (CC, DD, AA, BB, X (02), 16#2ad7d2bb#, S43); --  63
333      II (BB, CC, DD, AA, X (09), 16#eb86d391#, S44); --  64
334
335      H (0) := H (0) + AA;
336      H (1) := H (1) + BB;
337      H (2) := H (2) + CC;
338      H (3) := H (3) + DD;
339
340   end Transform;
341
342end GNAT.Secure_Hashes.MD5;
343