misc/uSHA.pas
changeset 3697 d5b30d6373fc
parent 3407 dcc129c4352e
equal deleted inserted replaced
3695:c11abf387a7d 3697:d5b30d6373fc
       
     1 (*
       
     2  * Hedgewars, a free turn based strategy game
       
     3  * Copyright (c) 2004-2010 Andrey Korotaev <unC0Rr@gmail.com>
       
     4  *
       
     5  * This program is free software; you can redistribute it and/or modify
       
     6  * it under the terms of the GNU General Public License as published by
       
     7  * the Free Software Foundation; version 2 of the License
       
     8  *
       
     9  * This program is distributed in the hope that it will be useful,
       
    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
       
    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
       
    12  * GNU General Public License for more details.
       
    13  *
       
    14  * You should have received a copy of the GNU General Public License
       
    15  * along with this program; if not, write to the Free Software
       
    16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
       
    17  *)
       
    18 
       
    19 {$INCLUDE "options.inc"}
       
    20 
       
    21 unit uSHA;
       
    22 interface
       
    23 uses SDLh;
       
    24 
       
    25 type TSHA1Context = packed record
       
    26                     H: array[0..4] of LongWord;
       
    27                     Length, CurrLength: Int64;
       
    28                     Buf: array[0..63] of byte;
       
    29                     end;
       
    30      TSHA1Digest =  array[0..4] of LongWord;
       
    31 
       
    32 procedure SHA1Init(var Context: TSHA1Context);
       
    33 procedure SHA1Update(var Context: TSHA1Context; Buf: PByteArray; Length: LongWord);
       
    34 procedure SHA1UpdateLongwords(var Context: TSHA1Context; Buf: PLongwordArray; Length: LongWord);
       
    35 function  SHA1Final(Context: TSHA1Context): TSHA1Digest;
       
    36 
       
    37 implementation
       
    38 
       
    39 function rol(x: LongWord; y: Byte): LongWord;
       
    40 begin
       
    41   rol:= (X shl y) or (X shr (32 - y))
       
    42 end;
       
    43 
       
    44 function Ft(t, b, c, d: LongWord): LongWord;
       
    45 begin
       
    46 case t of
       
    47       0..19: Ft := (b and c) or ((not b) and d);
       
    48      20..39: Ft :=  b xor c xor d;
       
    49      40..59: Ft := (b and c) or (b and d) or (c and d);
       
    50      else    Ft :=  b xor c xor d;
       
    51   end;
       
    52 end;
       
    53 
       
    54 function Kt(t: Byte): LongWord;
       
    55 begin
       
    56   case t of
       
    57      0..19: Kt := $5A827999;
       
    58     20..39: Kt := $6ED9EBA1;
       
    59     40..59: Kt := $8F1BBCDC;
       
    60   else
       
    61     Kt := $CA62C1D6
       
    62   end;
       
    63 end;
       
    64 
       
    65 
       
    66 procedure SHA1Hash(var Context: TSHA1Context);
       
    67 var S: array[0..4 ] of LongWord;
       
    68     W: array[0..79] of LongWord;
       
    69     i, t: LongWord;
       
    70 begin
       
    71 {$HINTS OFF}
       
    72 move(Context.H, S, sizeof(S));
       
    73 {$HINTS ON}
       
    74 for i:= 0 to 15 do
       
    75     SDLNet_Write32(PLongWordArray(@Context.Buf)^[i], @W[i]);
       
    76 
       
    77 for i := 16 to 79 do
       
    78     W[i] := rol(W[i - 3] xor W[i - 8] xor W[i - 14] xor W[i - 16], 1);
       
    79 
       
    80 for i := 0 to 79 do
       
    81     begin
       
    82     t:= rol(S[0], 5) + Ft(i, S[1], S[2], S[3]) + S[4] + W[i] + Kt(i);
       
    83     S[4]:= S[3];
       
    84     S[3]:= S[2];
       
    85     S[2]:= rol(S[1], 30);
       
    86     S[1]:= S[0];
       
    87     S[0]:= t
       
    88     end;
       
    89 
       
    90 for i := 0 to 4 do
       
    91     Context.H[i]:= Context.H[i] + S[i]
       
    92 end;
       
    93 
       
    94 procedure SHA1Init(var Context: TSHA1Context);
       
    95 begin
       
    96   with Context do
       
    97        begin
       
    98        Length    := 0;
       
    99        CurrLength:= 0;
       
   100        H[0]:= $67452301;
       
   101        H[1]:= $EFCDAB89;
       
   102        H[2]:= $98BADCFE;
       
   103        H[3]:= $10325476;
       
   104        H[4]:= $C3D2E1F0
       
   105   end
       
   106 end;
       
   107 
       
   108 procedure SHA1Update(var Context: TSHA1Context; Buf: PByteArray; Length: LongWord);
       
   109 var i: Longword;
       
   110 begin
       
   111 for i:= 0 to Pred(Length) do
       
   112     begin
       
   113     Context.Buf[Context.CurrLength]:= Buf^[i];
       
   114     inc(Context.CurrLength);
       
   115     if Context.CurrLength = 64 then
       
   116        begin
       
   117        SHA1Hash(Context);
       
   118        inc(Context.Length, 512);
       
   119        Context.CurrLength:= 0
       
   120        end
       
   121     end
       
   122 end;
       
   123 
       
   124 procedure SHA1UpdateLongwords(var Context: TSHA1Context; Buf: PLongwordArray; Length: LongWord);
       
   125 var i: Longword;
       
   126 begin
       
   127     for i:= 0 to Pred(Length div 4) do
       
   128     begin
       
   129         SDLNet_Write32(Buf^[i], @Context.Buf[Context.CurrLength]);
       
   130         inc(Context.CurrLength, 4);
       
   131         if Context.CurrLength = 64 then
       
   132         begin
       
   133             SHA1Hash(Context);
       
   134             inc(Context.Length, 512);
       
   135             Context.CurrLength:= 0
       
   136         end
       
   137     end
       
   138 end;
       
   139 
       
   140 function  SHA1Final(Context: TSHA1Context): TSHA1Digest;
       
   141 var i: LongWord;
       
   142 begin
       
   143     Context.Length:= Context.Length + Context.CurrLength shl 3;
       
   144     Context.Buf[Context.CurrLength]:= $80;
       
   145     inc(Context.CurrLength);
       
   146 
       
   147     if Context.CurrLength > 56 then
       
   148     begin
       
   149         FillChar(Context.Buf[Context.CurrLength], 64 - Context.CurrLength, 0);
       
   150         Context.CurrLength:= 64;
       
   151         SHA1Hash(Context);
       
   152         Context.CurrLength:=0
       
   153     end;
       
   154 
       
   155     FillChar(Context.Buf[Context.CurrLength], 56 - Context.CurrLength, 0);
       
   156 
       
   157     for i:= 56 to 63 do
       
   158         Context.Buf[i] := (Context.Length shr ((63 - i) * 8)) and $FF;
       
   159     SHA1Hash(Context);
       
   160     for i:= 0 to 4 do
       
   161         SHA1Final[i]:= Context.H[i];
       
   162 
       
   163     FillChar(Context, sizeof(Context), 0)
       
   164 end;
       
   165 
       
   166 end.