重新组织编写Delphi的MD2、MD4、MD5类

unit MessageDigest;

interface

uses SysUtils, Classes;

type
THashValue128 = array[0..15] of Byte;

TMDRecord128 = packed record
case Integer of
0: (ByteValue: THashValue128);
1: (LongValue: array[0..3] of LongWord);
end;

(*$NODEFINE THashValue128*)
(*$NODEFINE TMDRecord128*)
(*$HPPEMIT '#pragma pack(push, 1)'*)
(*$HPPEMIT 'struct THashValue128'*)
(*$HPPEMIT '{'*)
(*$HPPEMIT ' Byte data[16];'*)
(*$HPPEMIT ' Byte operator[](int Index){ return data[Index]; }'*)
(*$HPPEMIT ' operator Byte* (){ return data; }'*)
(*$HPPEMIT '};'*)
(*$HPPEMIT 'typedef THashValue128 TMDRecord128;'*)
(*$HPPEMIT '#pragma pack(pop)'*)

TMessageDigest = class
private
FState: TMDRecord128;
FBuffer: array [0..63] of Byte;
FBufSize: Integer;
protected
procedure Init; virtual; abstract;
procedure Final(LastSize: Integer; Count: Int64); virtual; abstract;
procedure Transform; virtual; abstract;
public
class function AsHex(const Value: THashValue128): string;
{$IFDEF UNICODE}
function HashValue(const Src: AnsiString): THashValue128; overload;
{$ENDIF}
function HashValue(const Src: string): THashValue128; overload;
function HashValue(AStream: TStream;
StartPos: Int64 = 0; Size: Int64 = 0): THashValue128; overload;
end;

TMessageDigest2 = class(TMessageDigest)
private
FX: array[0..47] of Byte; // 384bit
FCheckSum: THashValue128;
protected
procedure Init; override;
procedure Final(LastSize: Integer; Count: Int64); override;
procedure Transform; override;
end;

TMessageDigest4 = class(TMessageDigest)
protected
procedure Init; override;
procedure Final(LastSize: Integer; Count: Int64); override;
procedure Transform; override;
end;

TMessageDigest5 = class(TMessageDigest4)
protected
procedure Transform; override;
public

end;

implementation

{ TMessageDigest }

class function TMessageDigest.AsHex(const Value: THashValue128): string;
const
HexDigits: array[0..15] of char = '0123456789ABCDEF';
var
I: Integer;
begin
SetLength(Result, 32);
for I := 0 to 15 do
begin
Result[I shl 1 + 1] := HexDigits[Value[I] shr 4];
Result[I shl 1 + 2] := HexDigits[Value[I] and $F];
end;
end;

{$IFDEF UNICODE}
function TMessageDigest.HashValue(const Src: AnsiString): THashValue128;
{$ELSE}
function TMessageDigest.HashValue(const Src: string): THashValue128;
{$ENDIF}
var
I, Len, Count: Integer;
begin
Init;
Count := Length(Src);
Len := Count + 1;
I := 1;
while Len - I >= FBufSize do
begin
Move(Src[I], FBuffer, FBufSize);
Transform;
Inc(I, FBufSize);
end;
Dec(Len, I);
if Len > 0 then
Move(Src[I], FBuffer, Len);
Final(Len, Count);
Result := FState.ByteValue;
end;

{$IFDEF UNICODE}
function TMessageDigest.HashValue(const Src: string): THashValue128;
begin
Result := HashValue(AnsiString(Src));
end;
{$ENDIF}

function TMessageDigest.HashValue(AStream: TStream; StartPos, Size: Int64): THashValue128;
var
Count: Int64;
begin
if (StartPos >= 0) or (StartPos <= AStream.Size) then
AStream.Position := StartPos;
if (Size <= 0) or (Size > AStream.Size - AStream.Position) then
Size := AStream.Size
else Size := Size + AStream.Position;
Count := Size - AStream.Position;
Init;
while Size - AStream.Position >= FBufSize do
begin
AStream.Read(FBuffer, FBufSize);
Transform;
end;
Size := AStream.Read(FBuffer, Size - AStream.Position);
FInal(Size, Count);
Result := FState.ByteValue;
end;

const
MD2_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);

{ TMessageDigest2 }

procedure TMessageDigest2.Final(LastSize: Integer; Count: Int64);
var
Pad: Byte;
begin
Pad := 16 - LastSize;
// Step 1
FillChar(FBuffer[LastSize], Pad, Pad);
Transform;
// Step 2
Move(FCheckSum, FBuffer, 16);
Transform;
Move(FX, FState, 16);
end;

procedure TMessageDigest2.Init;
begin
FBufSize := 16;
FillChar(FCheckSum, 16, 0);
FillChar(FBuffer, 16, 0);
FillChar(FX, Sizeof(FX), 0);
end;

procedure TMessageDigest2.Transform;
const
NumRounds = 18;
var
x: Byte;
i, j: Integer;
T: Word;
LCheckSumScore: Byte;
begin
// Move the next 16 bytes into the second 16 bytes of X.
for i := 0 to 15 do
begin
x := FBuffer[i];
FX[i + 16] := x;
FX[i + 32] := x xor FX[i];
end;
{ Do 18 rounds. }
T := 0;
for i := 0 to NumRounds - 1 do
begin
for j := 0 to 47 do
begin
T := FX[j] xor MD2_PI_SUBST[T];
FX[j] := T;// and $FF;
end;
T := (T + i) and $FF;
end;

LCheckSumScore := FChecksum[15];
for i := 0 to 15 do
begin
x := FBuffer[i] xor LCheckSumScore;
LCheckSumScore := FChecksum[i] xor MD2_PI_SUBST[x];
FChecksum[i] := LCheckSumScore;
end;
end;

{ TMessageDigest4 }

const
MD4_INIT_VALUES: array[0..3] of LongWord = (
$67452301, $EFCDAB89, $98BADCFE, $10325476);

function ROL(AVal: LongWord; AShift: Byte): LongWord;
asm
mov cl, dl
rol eax, cl
// Result := (AVal shl AShift) or (AVal shr (32 - AShift));
end;

procedure TMessageDigest4.Final(LastSize: Integer; Count: Int64);
var
I: Integer;
begin
// Append one bit with value 1
FBuffer[LastSize] := $80;
Inc(LastSize);
// Must have sufficient space to insert the 64-bit size value
if LastSize > 56 then
begin
FillChar(FBuffer[LastSize], 64 - LastSize, 0);
Transform;
LastSize := 0;
end;
// Pad with zeroes. Leave room for the 64 bit size value.
FillChar(FBuffer[LastSize], 56 - LastSize, 0);
// Append the Number of bits processed.
Count := Count shl 3;
for I := 56 to 63 do
begin
FBuffer[I] := Count and $FF;
Count := Count shr 8;
end;
Transform;
end;

procedure TMessageDigest4.Init;
begin
FBufSize := 64;
Move(MD4_INIT_VALUES, FState, 16);
end;

procedure TMessageDigest4.Transform;
var
A, B, C, D, i : LongWord;
buff : array[0..15] of LongWord; // 64-byte buffer
begin
A := FState.LongValue[0];
B := FState.LongValue[1];
C := FState.LongValue[2];
D := FState.LongValue[3];
Move(FBuffer, buff, Sizeof(buff));
// Round 1
for i := 0 to 3 do
begin
A := ROL((((D xor C) and B) xor D) + A + buff[i*4+0], 3);
D := ROL((((C xor B) and A) xor C) + D + buff[i*4+1], 7);
C := ROL((((B xor A) and D) xor B) + C + buff[i*4+2], 11);
B := ROL((((A xor D) and C) xor A) + B + buff[i*4+3], 19);
end;
// Round 2
for i := 0 to 3 do
begin
A := ROL(((B and C) or (D and (B or C))) + A + buff[0*4+i] + $5A827999, 3);
D := ROL(((A and B) or (C and (A or B))) + D + buff[1*4+i] + $5A827999, 5);
C := ROL(((D and A) or (B and (D or A))) + C + buff[2*4+i] + $5A827999, 9);
B := ROL(((C and D) or (A and (C or D))) + B + buff[3*4+i] + $5A827999, 13);
end;
// Round 3
A := ROL((B xor C xor D) + A + buff[ 0] + $6ED9EBA1, 3);
D := ROL((A xor B xor C) + D + buff[ 8] + $6ED9EBA1, 9);
C := ROL((D xor A xor B) + C + buff[ 4] + $6ED9EBA1, 11);
B := ROL((C xor D xor A) + B + buff[12] + $6ED9EBA1, 15);
A := ROL((B xor C xor D) + A + buff[ 2] + $6ED9EBA1, 3);
D := ROL((A xor B xor C) + D + buff[10] + $6ED9EBA1, 9);
C := ROL((D xor A xor B) + C + buff[ 6] + $6ED9EBA1, 11);
B := ROL((C xor D xor A) + B + buff[14] + $6ED9EBA1, 15);
A := ROL((B xor C xor D) + A + buff[ 1] + $6ED9EBA1, 3);
D := ROL((A xor B xor C) + D + buff[ 9] + $6ED9EBA1, 9);
C := ROL((D xor A xor B) + C + buff[ 5] + $6ED9EBA1, 11);
B := ROL((C xor D xor A) + B + buff[13] + $6ED9EBA1, 15);
A := ROL((B xor C xor D) + A + buff[ 3] + $6ED9EBA1, 3);
D := ROL((A xor B xor C) + D + buff[11] + $6ED9EBA1, 9);
C := ROL((D xor A xor B) + C + buff[ 7] + $6ED9EBA1, 11);
B := ROL((C xor D xor A) + B + buff[15] + $6ED9EBA1, 15);

Inc(FState.LongValue[0], A);
Inc(FState.LongValue[1], B);
Inc(FState.LongValue[2], C);
Inc(FState.LongValue[3], D);
end;

{ TMessageDigest5 }

const
MD5_SINE : array [1..64] of LongWord = (
{ Round 1. }
$d76aa478, $e8c7b756, $242070db, $c1bdceee, $f57c0faf, $4787c62a,
$a8304613, $fd469501, $698098d8, $8b44f7af, $ffff5bb1, $895cd7be,
$6b901122, $fd987193, $a679438e, $49b40821,
{ Round 2. }
$f61e2562, $c040b340, $265e5a51, $e9b6c7aa, $d62f105d, $02441453,
$d8a1e681, $e7d3fbc8, $21e1cde6, $c33707d6, $f4d50d87, $455a14ed,
$a9e3e905, $fcefa3f8, $676f02d9, $8d2a4c8a,
{ Round 3. }
$fffa3942, $8771f681, $6d9d6122, $fde5380c, $a4beea44, $4bdecfa9,
$f6bb4b60, $bebfbc70, $289b7ec6, $eaa127fa, $d4ef3085, $04881d05,
$d9d4d039, $e6db99e5, $1fa27cf8, $c4ac5665,
{ Round 4. }
$f4292244, $432aff97, $ab9423a7, $fc93a039, $655b59c3, $8f0ccc92,
$ffeff47d, $85845dd1, $6fa87e4f, $fe2ce6e0, $a3014314, $4e0811a1,
$f7537e82, $bd3af235, $2ad7d2bb, $eb86d391
);

procedure TMessageDigest5.Transform;
var
A, B, C, D: LongWord;
x : array[0..15] of LongWord; // 64-byte buffer
begin
A := FState.LongValue[0];
B := FState.LongValue[1];
C := FState.LongValue[2];
D := FState.LongValue[3];
Move(FBuffer, x, Sizeof(x));
{ Round 1 }
A := ROL(A + (((D xor C) and B) xor D) + x[ 0] + MD5_SINE[ 1], 7) + B;
D := ROL(D + (((C xor B) and A) xor C) + x[ 1] + MD5_SINE[ 2], 12) + A;
C := ROL(C + (((B xor A) and D) xor B) + x[ 2] + MD5_SINE[ 3], 17) + D;
B := ROL(B + (((A xor D) and C) xor A) + x[ 3] + MD5_SINE[ 4], 22) + C;
A := ROL(A + (((D xor C) and B) xor D) + x[ 4] + MD5_SINE[ 5], 7) + B;
D := ROL(D + (((C xor B) and A) xor C) + x[ 5] + MD5_SINE[ 6], 12) + A;
C := ROL(C + (((B xor A) and D) xor B) + x[ 6] + MD5_SINE[ 7], 17) + D;
B := ROL(B + (((A xor D) and C) xor A) + x[ 7] + MD5_SINE[ 8], 22) + C;
A := ROL(A + (((D xor C) and B) xor D) + x[ 8] + MD5_SINE[ 9], 7) + B;
D := ROL(D + (((C xor B) and A) xor C) + x[ 9] + MD5_SINE[10], 12) + A;
C := ROL(C + (((B xor A) and D) xor B) + x[10] + MD5_SINE[11], 17) + D;
B := ROL(B + (((A xor D) and C) xor A) + x[11] + MD5_SINE[12], 22) + C;
A := ROL(A + (((D xor C) and B) xor D) + x[12] + MD5_SINE[13], 7) + B;
D := ROL(D + (((C xor B) and A) xor C) + x[13] + MD5_SINE[14], 12) + A;
C := ROL(C + (((B xor A) and D) xor B) + x[14] + MD5_SINE[15], 17) + D;
B := ROL(B + (((A xor D) and C) xor A) + x[15] + MD5_SINE[16], 22) + C;
{ Round 2 }
A := ROL(A + (C xor (D and (B xor C))) + x[ 1] + MD5_SINE[17], 5) + B;
D := ROL(D + (B xor (C and (A xor B))) + x[ 6] + MD5_SINE[18], 9) + A;
C := ROL(C + (A xor (B and (D xor A))) + x[11] + MD5_SINE[19], 14) + D;
B := ROL(B + (D xor (A and (C xor D))) + x[ 0] + MD5_SINE[20], 20) + C;
A := ROL(A + (C xor (D and (B xor C))) + x[ 5] + MD5_SINE[21], 5) + B;
D := ROL(D + (B xor (C and (A xor B))) + x[10] + MD5_SINE[22], 9) + A;
C := ROL(C + (A xor (B and (D xor A))) + x[15] + MD5_SINE[23], 14) + D;
B := ROL(B + (D xor (A and (C xor D))) + x[ 4] + MD5_SINE[24], 20) + C;
A := ROL(A + (C xor (D and (B xor C))) + x[ 9] + MD5_SINE[25], 5) + B;
D := ROL(D + (B xor (C and (A xor B))) + x[14] + MD5_SINE[26], 9) + A;
C := ROL(C + (A xor (B and (D xor A))) + x[ 3] + MD5_SINE[27], 14) + D;
B := ROL(B + (D xor (A and (C xor D))) + x[ 8] + MD5_SINE[28], 20) + C;
A := ROL(A + (C xor (D and (B xor C))) + x[13] + MD5_SINE[29], 5) + B;
D := ROL(D + (B xor (C and (A xor B))) + x[ 2] + MD5_SINE[30], 9) + A;
C := ROL(C + (A xor (B and (D xor A))) + x[ 7] + MD5_SINE[31], 14) + D;
B := ROL(B + (D xor (A and (C xor D))) + x[12] + MD5_SINE[32], 20) + C;
{ Round 3. }
A := ROL(A + (B xor C xor D) + x[ 5] + MD5_SINE[33], 4) + B;
D := ROL(D + (A xor B xor C) + x[ 8] + MD5_SINE[34], 11) + A;
C := ROL(C + (D xor A xor B) + x[11] + MD5_SINE[35], 16) + D;
B := ROL(B + (C xor D xor A) + x[14] + MD5_SINE[36], 23) + C;
A := ROL(A + (B xor C xor D) + x[ 1] + MD5_SINE[37], 4) + B;
D := ROL(D + (A xor B xor C) + x[ 4] + MD5_SINE[38], 11) + A;
C := ROL(C + (D xor A xor B) + x[ 7] + MD5_SINE[39], 16) + D;
B := ROL(B + (C xor D xor A) + x[10] + MD5_SINE[40], 23) + C;
A := ROL(A + (B xor C xor D) + x[13] + MD5_SINE[41], 4) + B;
D := ROL(D + (A xor B xor C) + x[ 0] + MD5_SINE[42], 11) + A;
C := ROL(C + (D xor A xor B) + x[ 3] + MD5_SINE[43], 16) + D;
B := ROL(B + (C xor D xor A) + x[ 6] + MD5_SINE[44], 23) + C;
A := ROL(A + (B xor C xor D) + x[ 9] + MD5_SINE[45], 4) + B;
D := ROL(D + (A xor B xor C) + x[12] + MD5_SINE[46], 11) + A;
C := ROL(C + (D xor A xor B) + x[15] + MD5_SINE[47], 16) + D;
B := ROL(B + (C xor D xor A) + x[ 2] + MD5_SINE[48], 23) + C;
{ Round 4. }
A := ROL(A + ((B or not D) xor C) + x[ 0] + MD5_SINE[49], 6) + B;
D := ROL(D + ((A or not C) xor B) + x[ 7] + MD5_SINE[50], 10) + A;
C := ROL(C + ((D or not B) xor A) + x[14] + MD5_SINE[51], 15) + D;
B := ROL(B + ((C or not A) xor D) + x[ 5] + MD5_SINE[52], 21) + C;
A := ROL(A + ((B or not D) xor C) + x[12] + MD5_SINE[53], 6) + B;
D := ROL(D + ((A or not C) xor B) + x[ 3] + MD5_SINE[54], 10) + A;
C := ROL(C + ((D or not B) xor A) + x[10] + MD5_SINE[55], 15) + D;
B := ROL(B + ((C or not A) xor D) + x[ 1] + MD5_SINE[56], 21) + C;
A := ROL(A + ((B or not D) xor C) + x[ 8] + MD5_SINE[57], 6) + B;
D := ROL(D + ((A or not C) xor B) + x[15] + MD5_SINE[58], 10) + A;
C := ROL(C + ((D or not B) xor A) + x[ 6] + MD5_SINE[59], 15) + D;
B := ROL(B + ((C or not A) xor D) + x[13] + MD5_SINE[60], 21) + C;
A := ROL(A + ((B or not D) xor C) + x[ 4] + MD5_SINE[61], 6) + B;
D := ROL(D + ((A or not C) xor B) + x[11] + MD5_SINE[62], 10) + A;
C := ROL(C + ((D or not B) xor A) + x[ 2] + MD5_SINE[63], 15) + D;
B := ROL(B + ((C or not A) xor D) + x[ 9] + MD5_SINE[64], 21) + C;

Inc(FState.LongValue[0], A);
Inc(FState.LongValue[1], B);
Inc(FState.LongValue[2], C);
Inc(FState.LongValue[3], D);
end;

end.