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Форум » Delphi » Уроки » Вычисление хеш-суммы MD5
Вычисление хеш-суммы MD5
vavilov8Дата: Четверг, 05.01.2012, 18:30 | Сообщение # 1
Титул: Генералиссимус
Сообщений: 10
Репутация: [ 0 ]
Вычисление хеш-суммы MD5

Code

{ MD5 Hashsum Evaluation Unit For Borland Delphi }
{ }
{ Copyright c 2002 by Dimka Maslov }
{ E-mail: mainbox@endimus.com , }
{ Web-site: http://www.endimus.com }
{ }
{ Derived from the RSA Data Security, Inc. }
{ MD5 Message-Digest Algorithm described in RFC 1321 }
{ http://www.faqs.org/rfcs/rfc1321.html }
{******************************************************************}

unit md5;

interface

uses Windows, SysUtils, Classes;

type
{ Тип TMD5Digest используется для получения
результата функций вычисления хеш-суммы.
Содержимое записи можно использовать
как набор из 4 целых чисел, или как
массив из 16 байт }
PMD5Digest = ^TMD5Digest;
TMD5Digest = record
case Integer of
0: (A, B, C, D: LongInt);
1: (v: array[0..15] of Byte);
end;

// вычисление хеш-суммы для строки
function MD5String(const S: string): TMD5Digest;

// вычисление хеш-суммы для файла
function MD5File(const FileName: string): TMD5Digest;

// вычисление хеш-суммы для содержиого потока Stream
function MD5Stream(const Stream: TStream): TMD5Digest;

// вычисление хеш-суммы для произвольного буфера
function MD5Buffer(const Buffer; Size: Integer): TMD5Digest;

// преобразование хеш-суммы в строку из шестнадцатеричных цифр
function MD5DigestToStr(const Digest: TMD5Digest): string;

// сравнение двух хеш-сумм
function MD5DigestCompare(const Digest1, Digest2: TMD5Digest): Boolean;

implementation

{
Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
rights reserved.

License to copy and use this software is granted provided that it
is identified as the "RSA Data Security, Inc. MD5 Message-Digest
Algorithm" in all material mentioning or referencing this software
or this function.

License is also granted to make and use derivative works provided
that such works are identified as "derived from the RSA Data
Security, Inc. MD5 Message-Digest Algorithm" in all material
mentioning or referencing the derived work.

RSA Data Security, Inc. makes no representations concerning either
the merchantability of this software or the suitability of this
software for any particular purpose. It is provided "as is"
without express or implied warranty of any kind.

These notices must be retained in any copies of any part of this
documentation and/or software.
}

type
UINT4 = LongWord;

PArray4UINT4 = ^TArray4UINT4;
TArray4UINT4 = array[0..3] of UINT4;
PArray2UINT4 = ^TArray2UINT4;
TArray2UINT4 = array[0..1] of UINT4;
PArray16Byte = ^TArray16Byte;
TArray16Byte = array[0..15] of Byte;
PArray64Byte = ^TArray64Byte;
TArray64Byte = array[0..63] of Byte;

PByteArray = ^TByteArray;
TByteArray = array[0..0] of Byte;

PUINT4Array = ^TUINT4Array;
TUINT4Array = array[0..0] of UINT4;

PMD5Context = ^TMD5Context;
TMD5Context = record
state: TArray4UINT4;
count: TArray2UINT4;
buffer: TArray64Byte;
end;

const
S11 = 7;
S12 = 12;
S13 = 17;
S14 = 22;
S21 = 5;
S22 = 9;
S23 = 14;
S24 = 20;
S31 = 4;
S32 = 11;
S33 = 16;
S34 = 23;
S41 = 6;
S42 = 10;
S43 = 15;
S44 = 21;

var
Padding: TArray64Byte =
($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);

function _F(x, y, z: UINT4): UINT4;
begin
Result := (((x) and (y)) or ((not x) and (z)));
end;

function _G(x, y, z: UINT4): UINT4;
begin
Result := (((x) and (z)) or ((y) and (not z)));
end;

function _H(x, y, z: UINT4): UINT4;
begin
Result := ((x) xor (y) xor (z));
end;

function _I(x, y, z: UINT4): UINT4;
begin
Result := ((y) xor ((x) or (not z)));
end;

function ROTATE_LEFT(x, n: UINT4): UINT4;
begin
Result := (((x) shl (n)) or ((x) shr (32 - (n))));
end;

procedure FF(var a: UINT4; b, c, d, x, s, ac: UINT4);
begin
a := a + _F(b, c, d) + x + ac;
a := ROTATE_LEFT(a, s);
a := a + b;
end;

procedure GG(var a: UINT4; b, c, d, x, s, ac: UINT4);
begin
a := a + _G(b, c, d) + x + ac;
a := ROTATE_LEFT(a, s);
a := a + b;
end;

procedure HH(var a: UINT4; b, c, d, x, s, ac: UINT4);
begin
a := a + _H(b, c, d) + x + ac;
a := ROTATE_LEFT(a, s);
a := a + b;
end;

procedure II(var a: UINT4; b, c, d, x, s, ac: UINT4);
begin
a := a + _I(b, c, d) + x + ac;
a := ROTATE_LEFT(a, s);
a := a + b;
end;

procedure MD5Encode(Output: PByteArray; Input: PUINT4Array; Len: LongWord);
var
i, j: LongWord;
begin
j := 0;
i := 0;
while j < Len do
begin
output[j] := Byte(input[i] and $FF);
output[j + 1] := Byte((input[i] shr  and $FF);
output[j + 2] := Byte((input[i] shr 16) and $FF);
output[j + 3] := Byte((input[i] shr 24) and $FF);
Inc(j, 4);
Inc(i);
end;

procedure MD5Decode(Output: PUINT4Array; Input: PByteArray; Len: LongWord);
var
i, j: LongWord;
begin
j := 0;
i := 0;
while j < Len do
begin
Output[i] := UINT4(input[j]) or (UINT4(input[j + 1]) shl  or
(UINT4(input[j + 2]) shl 16) or (UINT4(input[j + 3]) shl 24);
Inc(j, 4);
Inc(i);
end;

procedure MD5_memcpy(Output: PByteArray; Input: PByteArray; Len: LongWord);
begin
Move(Input^, Output^, Len);
end;

procedure MD5_memset(Output: PByteArray; Value: Integer; Len: LongWord);
begin
FillChar(Output^, Len, Byte(Value));
end;

procedure MD5Transform(State: PArray4UINT4; Buffer: PArray64Byte);
var
a, b, c, d: UINT4;
x: array[0..15] of UINT4;
begin
a := State[0];
b := State[1];
c := State[2];
d := State[3];
MD5Decode(PUINT4Array(@x), PByteArray(Buffer), 64);

FF(a, b, c, d, x[0], S11, $D76AA478);
FF(d, a, b, c, x[1], S12, $E8C7B756);
FF(c, d, a, b, x[2], S13, $242070DB);
FF(b, c, d, a, x[3], S14, $C1BDCEEE);
FF(a, b, c, d, x[4], S11, $F57C0FAF);
FF(d, a, b, c, x[5], S12, $4787C62A);
FF(c, d, a, b, x[6], S13, $A8304613);
FF(b, c, d, a, x[7], S14, $FD469501);
FF(a, b, c, d, x[8], S11, $698098D8);
FF(d, a, b, c, x[9], S12, $8B44F7AF);
FF(c, d, a, b, x[10], S13, $FFFF5BB1);
FF(b, c, d, a, x[11], S14, $895CD7BE);
FF(a, b, c, d, x[12], S11, $6B901122);
FF(d, a, b, c, x[13], S12, $FD987193);
FF(c, d, a, b, x[14], S13, $A679438E);
FF(b, c, d, a, x[15], S14, $49B40821);

GG(a, b, c, d, x[1], S21, $F61E2562);
GG(d, a, b, c, x[6], S22, $C040B340);
GG(c, d, a, b, x[11], S23, $265E5A51);
GG(b, c, d, a, x[0], S24, $E9B6C7AA);
GG(a, b, c, d, x[5], S21, $D62F105D);
GG(d, a, b, c, x[10], S22, $2441453);
GG(c, d, a, b, x[15], S23, $D8A1E681);
GG(b, c, d, a, x[4], S24, $E7D3FBC8);
GG(a, b, c, d, x[9], S21, $21E1CDE6);
GG(d, a, b, c, x[14], S22, $C33707D6);
GG(c, d, a, b, x[3], S23, $F4D50D87);

GG(b, c, d, a, x[8], S24, $455A14ED);
GG(a, b, c, d, x[13], S21, $A9E3E905);
GG(d, a, b, c, x[2], S22, $FCEFA3F8);
GG(c, d, a, b, x[7], S23, $676F02D9);
GG(b, c, d, a, x[12], S24, $8D2A4C8A);

HH(a, b, c, d, x[5], S31, $FFFA3942);
HH(d, a, b, c, x[8], S32, $8771F681);
HH(c, d, a, b, x[11], S33, $6D9D6122);
HH(b, c, d, a, x[14], S34, $FDE5380C);
HH(a, b, c, d, x[1], S31, $A4BEEA44);
HH(d, a, b, c, x[4], S32, $4BDECFA9);
HH(c, d, a, b, x[7], S33, $F6BB4B60);
HH(b, c, d, a, x[10], S34, $BEBFBC70);
HH(a, b, c, d, x[13], S31, $289B7EC6);
HH(d, a, b, c, x[0], S32, $EAA127FA);
HH(c, d, a, b, x[3], S33, $D4EF3085);
HH(b, c, d, a, x[6], S34, $4881D05);
HH(a, b, c, d, x[9], S31, $D9D4D039);
HH(d, a, b, c, x[12], S32, $E6DB99E5);
HH(c, d, a, b, x[15], S33, $1FA27CF8);
HH(b, c, d, a, x[2], S34, $C4AC5665);

II(a, b, c, d, x[0], S41, $F4292244);
II(d, a, b, c, x[7], S42, $432AFF97);
II(c, d, a, b, x[14], S43, $AB9423A7);
II(b, c, d, a, x[5], S44, $FC93A039);
II(a, b, c, d, x[12], S41, $655B59C3);
II(d, a, b, c, x[3], S42, $8F0CCC92);
II(c, d, a, b, x[10], S43, $FFEFF47D);
II(b, c, d, a, x[1], S44, $85845DD1);
II(a, b, c, d, x[8], S41, $6FA87E4F);
II(d, a, b, c, x[15], S42, $FE2CE6E0);
II(c, d, a, b, x[6], S43, $A3014314);
II(b, c, d, a, x[13], S44, $4E0811A1);
II(a, b, c, d, x[4], S41, $F7537E82);
II(d, a, b, c, x[11], S42, $BD3AF235);
II(c, d, a, b, x[2], S43, $2AD7D2BB);
II(b, c, d, a, x[9], S44, $EB86D391);

Inc(State[0], a);
Inc(State[1], b);
Inc(State[2], c);
Inc(State[3], d);

MD5_memset(PByteArray(@x), 0, SizeOf(x));
end;

procedure MD5Init(var Context: TMD5Context);
begin
FillChar(Context, SizeOf(Context), 0);
Context.state[0] := $67452301;
Context.state[1] := $EFCDAB89;
Context.state[2] := $98BADCFE;
Context.state[3] := $10325476;
end;

procedure MD5Update(var Context: TMD5Context; Input: PByteArray; InputLen:
LongWord);
var
i, index, partLen: LongWord;

begin
index := LongWord((context.count[0] shr 3) and $3F);
Inc(Context.count[0], UINT4(InputLen) shl 3);
if Context.count[0] < UINT4(InputLen) shl 3 then
Inc(Context.count[1]);
Inc(Context.count[1], UINT4(InputLen) shr 29);
partLen := 64 - index;
if inputLen >= partLen then
begin
MD5_memcpy(PByteArray(@Context.buffer[index]), Input, PartLen);
MD5Transform(@Context.state, @Context.buffer);
i := partLen;
while i + 63 < inputLen do
begin
MD5Transform(@Context.state, PArray64Byte(@Input[i]));
Inc(i, 64);
end;
index := 0;
end
else
i := 0;
MD5_memcpy(PByteArray(@Context.buffer[index]), PByteArray(@Input[i]), inputLen
- i);
end;

procedure MD5Final(var Digest: TMD5Digest; var Context: TMD5Context);
var
bits: array[0..7] of Byte;
index, padLen: LongWord;
begin
MD5Encode(PByteArray(@bits), PUINT4Array(@Context.count), 8);
index := LongWord((Context.count[0] shr 3) and $3F);
if index < 56 then
padLen := 56 - index
else
padLen := 120 - index;
MD5Update(Context, PByteArray(@PADDING), padLen);
MD5Update(Context, PByteArray(@Bits), 8);
MD5Encode(PByteArray(@Digest), PUINT4Array(@Context.state), 16);
MD5_memset(PByteArray(@Context), 0, SizeOf(Context));
end;

function MD5DigestToStr(const Digest: TMD5Digest): string;
var
i: Integer;
begin
Result := '';
for i := 0 to 15 do
Result := Result + IntToHex(Digest.v[i], 2);
end;

function MD5String(const S: string): TMD5Digest;
begin
Result := MD5Buffer(PChar(S)^, Length(S));
end;

function MD5File(const FileName: string): TMD5Digest;
var
F: TFileStream;
begin
F := TFileStream.Create(FileName, fmOpenRead);
try
Result := MD5Stream(F);
finally
F.Free;
end;

function MD5Stream(const Stream: TStream): TMD5Digest;
var
Context: TMD5Context;
Buffer: array[0..4095] of Byte;
Size: Integer;
ReadBytes: Integer;
TotalBytes: Integer;
SavePos: Integer;
begin
MD5Init(Context);
Size := Stream.Size;
SavePos := Stream.Position;
TotalBytes := 0;
try
Stream.Seek(0, soFromBeginning);
repeat
ReadBytes := Stream.Read(Buffer, SizeOf(Buffer));
Inc(TotalBytes, ReadBytes);
MD5Update(Context, @Buffer, ReadBytes);
until (ReadBytes = 0) or (TotalBytes = Size);
finally
Stream.Seek(SavePos, soFromBeginning);
end;
MD5Final(Result, Context);
end;

function MD5Buffer(const Buffer; Size: Integer): TMD5Digest;
var
Context: TMD5Context;
begin
MD5Init(Context);
MD5Update(Context, PByteArray(@Buffer), Size);
MD5Final(Result, Context);
end;

function MD5DigestCompare(const Digest1, Digest2: TMD5Digest): Boolean;
begin
Result := False;
if Digest1.A <> Digest2.A then
Exit;
if Digest1.B <> Digest2.B then
Exit;
if Digest1.C <> Digest2.C then
Exit;
if Digest1.D <> Digest2.D then
Exit;
Result := True;
end;

end.
Форум » Delphi » Уроки » Вычисление хеш-суммы MD5
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