sha1.pas

来自「用于开发税务票据管理的软件」· PAS 代码 · 共 284 行 · 第 1/2 页

  Inc(E,((A shl 5) or (A shr 27)) + (B xor C xor D) + $CA62C1D6 + W[70]); B:= (B shl 30) or (B shr 2);
  Inc(D,((E shl 5) or (E shr 27)) + (A xor B xor C) + $CA62C1D6 + W[71]); A:= (A shl 30) or (A shr 2);
  Inc(C,((D shl 5) or (D shr 27)) + (E xor A xor B) + $CA62C1D6 + W[72]); E:= (E shl 30) or (E shr 2);
  Inc(B,((C shl 5) or (C shr 27)) + (D xor E xor A) + $CA62C1D6 + W[73]); D:= (D shl 30) or (D shr 2);
  Inc(A,((B shl 5) or (B shr 27)) + (C xor D xor E) + $CA62C1D6 + W[74]); C:= (C shl 30) or (C shr 2);
  Inc(E,((A shl 5) or (A shr 27)) + (B xor C xor D) + $CA62C1D6 + W[75]); B:= (B shl 30) or (B shr 2);
  Inc(D,((E shl 5) or (E shr 27)) + (A xor B xor C) + $CA62C1D6 + W[76]); A:= (A shl 30) or (A shr 2);
  Inc(C,((D shl 5) or (D shr 27)) + (E xor A xor B) + $CA62C1D6 + W[77]); E:= (E shl 30) or (E shr 2);
  Inc(B,((C shl 5) or (C shr 27)) + (D xor E xor A) + $CA62C1D6 + W[78]); D:= (D shl 30) or (D shr 2);
  Inc(A,((B shl 5) or (B shr 27)) + (C xor D xor E) + $CA62C1D6 + W[79]); C:= (C shl 30) or (C shr 2);

  CurrentHash[0]:= CurrentHash[0] + A;
  CurrentHash[1]:= CurrentHash[1] + B;
  CurrentHash[2]:= CurrentHash[2] + C;
  CurrentHash[3]:= CurrentHash[3] + D;
  CurrentHash[4]:= CurrentHash[4] + E;
  FillChar(W,Sizeof(W),0);
  FillChar(HashBuffer,Sizeof(HashBuffer),0);
end;

class function TDCP_sha1.GetAlgorithm: string;
begin
  Result:= 'SHA1';
end;

class function TDCP_sha1.GetId: longint;
begin
  Result:= DCP_sha1;
end;

class function TDCP_sha1.GetHashSize: longint;
begin
  Result:= 160;
end;

class function TDCP_sha1.SelfTest: boolean;
const
  Test1Out: array[0..19] of byte=
    ($A9,$99,$3E,$36,$47,$06,$81,$6A,$BA,$3E,$25,$71,$78,$50,$C2,$6C,$9C,$D0,$D8,$9D);
  Test2Out: array[0..19] of byte=
    ($84,$98,$3E,$44,$1C,$3B,$D2,$6E,$BA,$AE,$4A,$A1,$F9,$51,$29,$E5,$E5,$46,$70,$F1);
var
  TestHash: TDCP_sha1;
  TestOut: array[0..19] of byte;
begin
  TestHash:= TDCP_sha1.Create(nil);
  TestHash.Init;
  TestHash.UpdateStr('abc');
  TestHash.Final(TestOut);
  Result:= boolean(CompareMemory(@TestOut,@Test1Out,Sizeof(Test1Out)));
  TestHash.Init;
  TestHash.UpdateStr('abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq');
  TestHash.Final(TestOut);
  Result:= boolean(CompareMemory(@TestOut,@Test2Out,Sizeof(Test2Out))) and Result;
  TestHash.Free;
end;

procedure TDCP_sha1.Init;
begin
  Burn;
  CurrentHash[0]:= $67452301;
  CurrentHash[1]:= $EFCDAB89;
  CurrentHash[2]:= $98BADCFE;
  CurrentHash[3]:= $10325476;
  CurrentHash[4]:= $C3D2E1F0;
  fInitialized:= true;
end;

procedure TDCP_sha1.Burn;
begin
  LenHi:= 0; LenLo1:= 0; LenLo2:= 0;
  Index:= 0;
  FillChar(HashBuffer,Sizeof(HashBuffer),0);
  FillChar(CurrentHash,Sizeof(CurrentHash),0);
  fInitialized:= false;
end;

procedure TDCP_sha1.Update(const Buffer; Size: longint);
var
  PBuf: ^byte;
begin
  if not fInitialized then
    raise EDCP_hash.Create('Hash not initialized');

  { I wish Borland had included an unsigned 32bit from the start }
  Inc(LenLo1,(Size shl 3) and $FFFF);
  if LenLo1< ((Size shl 3) and $FFFF) then
  begin
    Inc(LenLo2);
    if LenLo2= 0 then
      Inc(LenHi);
  end;
  Inc(LenLo2,Size shr 13);
  if LenLo2< ((Size shr 13) and $FFFF) then
    Inc(LenHi);
  Inc(LenHi,Size shr 29);

  PBuf:= @Buffer;
  while Size> 0 do
  begin
    if (Sizeof(HashBuffer)-Index)<= DWord(Size) then
    begin
      Move(PBuf^,HashBuffer[Index],Sizeof(HashBuffer)-Index);
      Dec(Size,Sizeof(HashBuffer)-Index);
      Inc(PBuf,Sizeof(HashBuffer)-Index);
      Compress;
    end
    else
    begin
      Move(PBuf^,HashBuffer[Index],Size);
      Inc(Index,Size);
      Size:= 0;
    end;
  end;
end;

procedure TDCP_sha1.Final(var Digest);
begin
  if not fInitialized then
    raise EDCP_hash.Create('Hash not initialized');
  HashBuffer[Index]:= $80;
  if Index>= 56 then
    Compress;
  PDWord(@HashBuffer[56])^:= SwapDWord(LenHi);
  PDWord(@HashBuffer[60])^:= SwapDWord(LenLo1 or (longint(LenLo2) shl 16));
  Compress;
  CurrentHash[0]:= SwapDWord(CurrentHash[0]);
  CurrentHash[1]:= SwapDWord(CurrentHash[1]);
  CurrentHash[2]:= SwapDWord(CurrentHash[2]);
  CurrentHash[3]:= SwapDWord(CurrentHash[3]);
  CurrentHash[4]:= SwapDWord(CurrentHash[4]);
  Move(CurrentHash,Digest,Sizeof(CurrentHash));
  Burn;
end;


initialization
  RegisterClass(TDCP_sha1);
  DCPreghash(TDCP_sha1);

end.