hedgewars/uSHA.pas
changeset 102 c45643d3fd78
parent 101 f568cc72ea8c
child 103 8c56db04ea52
equal deleted inserted replaced
101:f568cc72ea8c 102:c45643d3fd78
     1 (*
       
     2  * Hedgewars, a worms-like game
       
     3  * Copyright (c) 2004, 2005 Andrey Korotaev <unC0Rr@gmail.com>
       
     4  *
       
     5  * Distributed under the terms of the BSD-modified licence:
       
     6  *
       
     7  * Permission is hereby granted, free of charge, to any person obtaining a copy
       
     8  * of this software and associated documentation files (the "Software"), to deal
       
     9  * with the Software without restriction, including without limitation the
       
    10  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
       
    11  * sell copies of the Software, and to permit persons to whom the Software is
       
    12  * furnished to do so, subject to the following conditions:
       
    13  *
       
    14  * 1. Redistributions of source code must retain the above copyright notice,
       
    15  *    this list of conditions and the following disclaimer.
       
    16  * 2. Redistributions in binary form must reproduce the above copyright notice,
       
    17  *    this list of conditions and the following disclaimer in the documentation
       
    18  *    and/or other materials provided with the distribution.
       
    19  * 3. The name of the author may not be used to endorse or promote products
       
    20  *    derived from this software without specific prior written permission.
       
    21  *
       
    22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
       
    23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
       
    24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
       
    25  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
       
    26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
       
    27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
       
    28  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
       
    29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
       
    30  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
       
    31  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
       
    32  *)
       
    33 
       
    34 unit uSHA;
       
    35 interface
       
    36 
       
    37 type TSHA1Context = packed record
       
    38                     H: array[0..4] of LongWord;
       
    39                     Length, CurrLength: Int64;
       
    40                     Buf: array[0..63] of byte;
       
    41                     end;
       
    42      TSHA1Digest = record
       
    43                    case byte of
       
    44                         0: (LongWords: array[0.. 4] of LongWord);
       
    45                         1: (    Words: array[0.. 9] of     Word);
       
    46                         2: (    Bytes: array[0..19] of     Byte)
       
    47                    end;
       
    48 
       
    49 procedure SHA1Init(var Context: TSHA1Context);
       
    50 procedure SHA1Update(var Context: TSHA1Context; Buf: Pointer; Length: LongWord);
       
    51 function  SHA1Final(Context: TSHA1Context): TSHA1Digest;
       
    52 
       
    53 implementation
       
    54 uses SDLh;
       
    55 
       
    56 function rol(x: LongWord; y: Byte): LongWord;
       
    57 begin
       
    58   Result:= (X shl y) or (X shr (32 - y))
       
    59 end;
       
    60 
       
    61 function Ft(t, b, c, d: LongWord): LongWord;
       
    62 begin
       
    63 case t of
       
    64       0..19: Result := (b and c) or ((not b) and d);
       
    65      20..39: Result :=  b xor c xor d;
       
    66      40..59: Result := (b and c) or (b and d) or (c and d);
       
    67      else    Result :=  b xor c xor d;
       
    68   end;
       
    69 end;
       
    70 
       
    71 function Kt(t: Byte): LongWord;
       
    72 begin
       
    73   case t of
       
    74      0..19: Result := $5A827999;
       
    75     20..39: Result := $6ED9EBA1;
       
    76     40..59: Result := $8F1BBCDC;
       
    77   else
       
    78     Result := $CA62C1D6
       
    79   end;
       
    80 end;
       
    81 
       
    82 
       
    83 procedure SHA1Hash(var Context: TSHA1Context);
       
    84 var S: array[0..4 ] of LongWord;
       
    85     W: array[0..79] of LongWord;
       
    86     i, t: LongWord;
       
    87 begin
       
    88 move(Context.H, S, sizeof(S));
       
    89 for i:= 0 to 3 do
       
    90     begin
       
    91     t:= i * 4;
       
    92     with Context do
       
    93          W[i]:= Buf[t + 3] or (Buf[t + 2] shl 8) or (Buf[t + 1] shl 16) or (Buf[t] shl 24);
       
    94     end;
       
    95 for i := 16 to 79 do
       
    96     W[i] := rol(W[i - 3] xor W[i - 8] xor W[i - 14] xor W[i - 16], 1);
       
    97 for i := 0 to 79 do
       
    98     begin
       
    99     t:= rol(S[0], 5) + Ft(i, S[1], S[2], S[3]) + S[4] + W[i] + Kt(i);
       
   100     S[4]:= S[3];
       
   101     S[3]:= S[2];
       
   102     S[2]:= rol(S[1], 30);
       
   103     S[1]:= S[0];
       
   104     S[0]:= t
       
   105     end;
       
   106 for i := 0 to 4 do
       
   107     Context.H[i]:= Context.H[i] + S[i]
       
   108 end;
       
   109 
       
   110 procedure SHA1Init(var Context: TSHA1Context);
       
   111 begin
       
   112   with Context do
       
   113        begin
       
   114        Length    := 0;
       
   115        CurrLength:= 0;
       
   116        H[0]:= $67452301;
       
   117        H[1]:= $EFCDAB89;
       
   118        H[2]:= $98BADCFE;
       
   119        H[3]:= $10325476;
       
   120        H[4]:= $C3D2E1F0
       
   121   end
       
   122 end;
       
   123 
       
   124 procedure SHA1Update(var Context: TSHA1Context; Buf: Pointer; Length: LongWord);
       
   125 var i: integer;
       
   126 begin
       
   127 for i:= 0 to Pred(Length) do
       
   128     begin
       
   129     Context.Buf[Context.CurrLength]:= PByteArray(Buf)^[i];
       
   130     inc(Context.CurrLength);
       
   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 if Context.CurrLength>56 then
       
   147    begin
       
   148    FillChar(Context.Buf[Context.CurrLength],64-Context.CurrLength,0);
       
   149    Context.CurrLength:= 64;
       
   150    SHA1Hash(Context);
       
   151    Context.CurrLength:=0
       
   152    end;
       
   153 FillChar(Context.Buf[Context.CurrLength],56-Context.CurrLength,0);
       
   154 for i:= 56 to 63 do
       
   155     Context.Buf[i] := (Context.Length shr ((63 - i) * 8)) and $FF;
       
   156 SHA1Hash(Context);
       
   157 move(Context.H, Result, sizeof(TSHA1Digest));
       
   158 FillChar(Context, sizeof(Context), 0)
       
   159 end;
       
   160 
       
   161 end.