shaunit.~pas

delphi实现加密算法 CRC32-Dym.................CRC32算法动态码表实现 CRC32-Static..............CRC32算法静态码表实现 MD

unit SHAUnit;

interface

type
  PSHACtx = ^TSHACtx;
  TSHACtx = record
    state: array[0..7] of LongWord;
    length, curlen: Int64;
    buf: array[0..63] of Byte;
  end;

procedure SHAInit(var md: TSHACtx);
procedure SHAUpdate(var md: TSHACtx; buf: Pointer; len: Int64; sz: Word);
function SHAFinal(var md: TSHACtx; sz: Word): String;
  
implementation

const
  HexChars: array[0..15] of Char = ('0', '1', '2', '3', '4', '5',
                                    '6', '7', '8', '9', 'a', 'b',
                                    'c', 'd', 'e', 'f');

//整数转换成16进制
function IntToHex(Int: Int64; IntSize: Byte): String;
var
  n: Byte;
begin
  Result := '';
  for n := 0 to IntSize - 1 do
  begin
    Result := HexChars[Int and $F] + Result;
    Int := Int shr $4;
  end;
end;

function ror(x: LongWord; y: Byte): LongWord; assembler;
asm
  mov   cl,dl
  ror   eax,cl
end;

function rol(x: LongWord; y: Byte): LongWord; assembler;
asm
  mov   cl,dl
  rol   eax,cl
end;

function Endian(X: LongWord): LongWord;
asm
  bswap eax
end;

function ft1(t: Byte; x, y, z: LongWord): LongWord;
begin
  case t of
    0..19: Result := (x and y) or ((not x) and z);
    20..39: Result := x xor y xor z;
    40..59: Result := (x and y) or (x and z) or (y and z);
  else
    Result := x xor y xor z;
  end;
end;

//四个常数
function Kt1(t: Byte): LongWord;
begin
  case t of
    0..19: Result := $5a827999;
    20..39: Result := $6ed9eba1;
    40..59: Result := $8f1bbcdc;
  else
    Result := $ca62c1d6
  end;
end;

procedure SHACompress(var md: TSHACtx);
var
  S: array[0..4] of LongWord;
  W: array[0..79] of LongWord;
  i, t: LongWord;
begin
  Move(md.state, S, SizeOf(S));
  for i := 0 to 15 do
    W[i] := Endian(PLongWord(LongWord(@md.buf) + i * 4)^);
  for i := 16 to 79 do
    W[i] := rol(W[i - 3] xor W[i - 8] xor W[i - 14] xor W[i - 16], 1);
    for i := 0 to 79 do
    begin
      t := rol(S[0], 5) + ft1(i, S[1], S[2], S[3]) + S[4] + Kt1(i) + W[i];
      S[4] := S[3];
      S[3] := S[2];
      S[2] := rol(S[1], 30);
      S[1] := S[0];
      S[0] := t;
    end;
  for i := 0 to 4 do
    md.state[i] := md.state[i] + S[i];
end;

//五个32位变量
procedure SHAInit(var md: TSHACtx);
begin
  md.curlen := 0; md.length := 0;
  md.state[0] := $67452301;
  md.state[1] := $efcdab89;
  md.state[2] := $98badcfe;
  md.state[3] := $10325476;
  md.state[4] := $c3d2e1f0;
end;

procedure SHAUpdate(var md: TSHACtx; buf: Pointer; len: Int64; sz: Word);
begin
  while (len > 0) do
  begin
    md.buf[md.curlen] := PByte(buf)^;
    md.curlen := md.curlen + 1;
    buf := Ptr(LongWord(buf) + 1);
    if (md.curlen = 64) then
    begin
      SHACompress(md);
      md.length := md.length + 512;
      md.curlen := 0;
    end;
    Dec(len);
  end;
end;

function SHAFinal(var md: TSHACtx; sz: Word): String;
var
  i: LongWord;
begin
  md.length := md.length + md.curlen shl 3;
  md.buf[md.curlen] := $80;
  md.curlen := md.curlen + 1;
  if (md.curlen > 56) then
  begin
    while md.curlen < 64 do
    begin
      md.buf[md.curlen] := 0;
      md.curlen := md.curlen + 1;
    end;
    SHACompress(md);
    md.curlen := 0;
  end;
  while md.curlen < 56 do
  begin
    md.buf[md.curlen] := 0;
    md.curlen := md.curlen + 1;
  end;
  for i := 56 to 63 do
    md.buf[i] := (md.length shr ((63 - i) * 8)) and $FF;
  SHACompress(md);
  Result := '';
  for i := 0 to 4 do
    Result := Result + IntToHex(md.state[i], 8);
end;

end.