md.pas

超级Delphi函数包,包括编程时常需要的一些函数

unit MD;
{(C) Coban ([e-mail])}

interface
uses
  CryptoUtils;

type
  PMD2CTX = ^TMD2CTX;
  TMD2CTX = record
    D: array[0..47] of Byte;   // buffer for forming digest in
    C: array[0..15] of Byte;   // checksum register
    i: Byte;                   // number of bytes handled mod 16
    L: Byte;                   // last checksum byte saved
  end;

  PMD4Ctx = ^TMD4Ctx;
  TMD4Ctx = record
    state: array[0..3] of LongWord;
    count: array[0..1] of LongWord;
    buffer: array[0..63] of Byte;
  end;

  TMDTransform = procedure(var state: array of LongWord; block: Pointer);

  procedure MD2Init(md: PMD2CTX);
  procedure MD2Update(md: PMD2CTX; SrcBuf: Pointer; BufLen: LongWord);
  function MD2Final(md: PMD2CTX): String;

  procedure MDInit(context: PMD4Ctx);
  procedure MDUpdate(context: PMD4Ctx; input: Pointer; inputLen: LongWord; tr_func: TMDTransform);
  procedure MD4Transform (var state: array of LongWord; block: Pointer);
  procedure MD5Transform (var state: array of LongWord; block: Pointer);
  function MDFinal(context: PMD4Ctx; tr_func: TMDTransform): String;  

implementation
const
  PI_SUBST: array[0..255] of Byte = (
    41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
    19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
    76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
    138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
    245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
    148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
    39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
    181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
    150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
    112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
    96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
    85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
    234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
    129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
    8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
    203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
    166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
    31, 26, 219, 153, 141, 51, 159, 17, 131, 20
  );

procedure MD2Init(md: PMD2CTX);
begin
  FillChar(md^.D, 16, 0);
  FillChar(md^.C, 16, 0);
  md^.i := 0; md^.L := 0;
end;

procedure MD2UpdateB(md: PMD2CTX; c: Byte);
var
  i, j, t: Byte;
  p: PByte;
begin
  i := md^.i;
  md^.D[16 + i] := c;
  md^.D[32 + i] := c xor md^.D[i];
  md^.C[i] := md^.C[i] xor PI_SUBST[$ff and (c xor md^.L)];
  md^.L := md^.C[i];
  md^.i := (i + 1) and 15;
  i := md^.i;
  if (i = 0) then
  begin
    t := 0;
    for j := 0 to 17 do
    begin
      p := @md.D;
      for i := 0 to 7 do
      begin
        p^ := p^ xor PI_SUBST[t]; t := p^; Inc(p);
        p^ := p^ xor PI_SUBST[t]; t := p^; Inc(p);
        p^ := p^ xor PI_SUBST[t]; t := p^; Inc(p);
        p^ := p^ xor PI_SUBST[t]; t := p^; Inc(p);
        p^ := p^ xor PI_SUBST[t]; t := p^; Inc(p);
        p^ := p^ xor PI_SUBST[t]; t := p^; Inc(p);
      end;
      t := t + j;
    end;
  end;
end;

procedure MD2Update(md: PMD2CTX; SrcBuf: Pointer; BufLen: LongWord);
var
  i: LongWord;
begin
  if BufLen > 0 then
    for i := 0 to BufLen - 1 do
      MD2UpdateB(md, PByte(LongWord(SrcBuf) + i)^);
end;

function MD2Final(md: PMD2CTX): String;
var
  i, padlen: LongWord;
begin
  padlen  := 16 - md^.i;
  for i := 0 to padlen - 1 do
    MD2UpdateB(md, padlen);
  for i := 0 to 15 do
    MD2UpdateB(md, md^.C[i]);
  for i := 0 to 15 do
    Result := Result + IntToHex(md.D[i], 2);
end;

const
  MD_PADDING: array[0..63] of Byte = (
    $80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  );

  S11 = 3;
  S12 = 7;
  S13 = 11;
  S14 = 19;
  S21 = 3;
  S22 = 5;
  S23 = 9;
  S24 = 13;
  S31 = 3;
  S32 = 9;
  S33 = 11;
  S34 = 15;

function F(x, y, z: LongWord): LongWord; assembler;
{begin
  Result := ((x and y) or ((not x) and (z)))
end;}
asm
  and   edx,eax
  not   eax
  and   eax,ecx
  or    eax,edx
end;

function G(x, y, z: LongWord): LongWord; assembler;
{begin
  Result := (x and y) or (x and z) or (y and z);
end;}
asm
  push  ecx
  and   ecx,eax
  and   eax,edx
  or    eax,ecx
  pop   ecx
  and   edx,ecx
  or    eax,edx
end;

function H(x, y, z: LongWord): LongWord; assembler;
{begin
  Result := x xor y xor z;
end;}
asm
  xor eax,edx
  xor eax,ecx
end;

procedure FF(var a: LongWord; b, c, d, x, s: LongWord);
begin
  a := a + (F(b, c, d) + x);
  a := rol(a, s);
end;

procedure GG(var a: LongWord; b, c, d, x, s: LongWord);
begin
  a := a + G(b, c, d) + x + $5a827999;
  a := rol(a, s);
end;

procedure HH(var a: LongWord; b, c, d, x, s: LongWord);
begin
  a := a + H(b, c, d) + x + $6ed9eba1;
  a := rol(a, s);
end;

procedure MDInit(context: PMD4Ctx);
begin
  context^.count[0] := 0;
  context^.count[1] := 0;
  context^.state[0] := $67452301;
  context^.state[1] := $efcdab89;
  context^.state[2] := $98badcfe;
  context^.state[3] := $10325476;
end;

procedure MDEncode(output, input: Pointer; len: LongWord);
var
  i, j: LongWord;
begin
  i := 0; j := 0;
  while j < len do
  begin
    PByteArray(output)^[j] := (PDWordArray(input)^[i] and $ff);
    PByteArray(output)^[j + 1] := ((PDWordArray(input)^[i] shr 8) and $ff);
    PByteArray(output)^[j + 2] := ((PDWordArray(input)^[i] shr 16) and $ff);
    PByteArray(output)^[j + 3] := ((PDWordArray(input)^[i] shr 24) and $ff);
    Inc(i); Inc(j, 4);
  end;
end;

procedure MDDecode(output, input: Pointer; len: LongWord);
var
  i, j: LongWord;
begin
  i := 0; j := 0;
  while j < len do
  begin
    PDWordArray(output)^[i] := PByteArray(input)^[j] or (PByteArray(input)^[j + 1] shl 8) or (PByteArray(input)^[j + 2] shl 16) or (PByteArray(input)^[j + 3] shl 24);
    Inc(i); Inc(j, 4);
  end;
end;

procedure MD4Transform (var state: array of LongWord; block: Pointer);
var
  a, b, c, d: LongWord;
  x: array[0..15] of LongWord;
begin
  a := state[0]; b := state[1]; c := state[2]; d := state[3];
  MDDecode(@x, block, 64);

  FF (a, b, c, d, x[ 0], S11); //* 1 */
  FF (d, a, b, c, x[ 1], S12); //* 2 */
  FF (c, d, a, b, x[ 2], S13); //* 3 */
  FF (b, c, d, a, x[ 3], S14); //* 4 */
  FF (a, b, c, d, x[ 4], S11); //* 5 */
  FF (d, a, b, c, x[ 5], S12); //* 6 */
  FF (c, d, a, b, x[ 6], S13); //* 7 */
  FF (b, c, d, a, x[ 7], S14); //* 8 */
  FF (a, b, c, d, x[ 8], S11); //* 9 */
  FF (d, a, b, c, x[ 9], S12); //* 10 */
  FF (c, d, a, b, x[10], S13); //* 11 */
  FF (b, c, d, a, x[11], S14); //* 12 */
  FF (a, b, c, d, x[12], S11); //* 13 */
  FF (d, a, b, c, x[13], S12); //* 14 */
  FF (c, d, a, b, x[14], S13); //* 15 */
  FF (b, c, d, a, x[15], S14); //* 16 */

  //* Round 2 */
  GG (a, b, c, d, x[ 0], S21); //* 17 */
  GG (d, a, b, c, x[ 4], S22); //* 18 */
  GG (c, d, a, b, x[ 8], S23); //* 19 */
  GG (b, c, d, a, x[12], S24); //* 20 */
  GG (a, b, c, d, x[ 1], S21); //* 21 */
  GG (d, a, b, c, x[ 5], S22); //* 22 */
  GG (c, d, a, b, x[ 9], S23); //* 23 */