Delphi与MD5 Hash函数的结果不同

时间：2017-01-26 16:38:47

标签： delphi md5

我在德尔福柏林工作 我尝试迁移一个旧项目，我坚持登录:) 我不能用新的MD5Hash替换md5单元中的旧功能RivestStr 为了测试行为，我创建了一个带有2个按钮和3个编辑的简单项目。

我的问题是这2个功能有不同的结果 而且我不确定如何让MD5Hash提供与RivestStr相同的结果。

uses IdHashMessageDigest, idHash  

function  MD5Hash(Value : String) : String;
var workHash : TIdHashMessageDigest5;
begin
  try
    workHash := TIdHashMessageDigest5.Create;
    Result   := workHash.HashStringAsHex(Value);
  finally
    FreeAndNil(workHash);
  end;
end;

procedure TForm5.Button1Click(Sender: TObject);
begin
  edResult.Text := MD5Hash(edPass.Text);
end;

procedure TForm5.Button2Click(Sender: TObject);
begin
  edRivest.Text := RivestStr(edPass.Text);
end;

unit md5;

interface

uses Windows, SysUtils, Classes;



type
  MD5Count = array[0..1] of DWORD;
  MD5State = array[0..3] of DWORD;
  MD5Block = array[0..15] of DWORD;
  MD5CBits = array[0..7] of Byte;
  MD5Digest = array[0..15] of Byte;
  MD5Buffer = array[0..63] of Byte;
  MD5Context = record
    State: MD5State;
    Count: MD5Count;
    Buffer: MD5Buffer;
  end;

procedure MD5Init(var Context: MD5Context);
procedure MD5Update(var Context: MD5Context; Input: pChar; Length: longword);
procedure MD5Final(var Context: MD5Context; var Digest: MD5Digest);

function MD5String(M: string): MD5Digest;
function MD5File(N: string): MD5Digest;
function MD5Print(D: MD5Digest): string;
function MD5Match(D1, D2: MD5Digest): Boolean;

function RivestStr(Str: string): string;
function RivestFile(FileName: string): string;


var

  PADDING: MD5Buffer = (
    $80, $00, $00, $00, $00, $00, $00, $00,
    $00, $00, $00, $00, $00, $00, $00, $00,
    $00, $00, $00, $00, $00, $00, $00, $00,
    $00, $00, $00, $00, $00, $00, $00, $00,
    $00, $00, $00, $00, $00, $00, $00, $00,
    $00, $00, $00, $00, $00, $00, $00, $00,
    $00, $00, $00, $00, $00, $00, $00, $00,
    $00, $00, $00, $00, $00, $00, $00, $00);

implementation






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

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

function H(x, y, z: DWORD): DWORD;
begin
  Result := x xor y xor z;
end;

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

procedure rot(var x: DWORD; n: BYTE);
begin
  x := (x shl n) or (x shr (32 - n));
end;

procedure FF(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
  inc(a, F(b, c, d) + x + ac);
  rot(a, s);
  inc(a, b);
end;

procedure GG(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
  inc(a, G(b, c, d) + x + ac);
  rot(a, s);
  inc(a, b);
end;

procedure HH(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
  inc(a, H(b, c, d) + x + ac);
  rot(a, s);
  inc(a, b);
end;

procedure II(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
  inc(a, I(b, c, d) + x + ac);
  rot(a, s);
  inc(a, b);
end;

procedure Encode(Source, Target: pointer; Count: longword);
var
  S: PByte;
  T: PDWORD;
  I: longword;
begin
  S := Source;
  T := Target;
  for I := 1 to Count div 4 do begin
    T^ := S^;
    inc(S);
    T^ := T^ or (S^ shl 8);
    inc(S);
    T^ := T^ or (S^ shl 16);
    inc(S);
    T^ := T^ or (S^ shl 24);
    inc(S);
    inc(T);
  end;
end;

procedure Decode(Source, Target: pointer; Count: longword);
var
  S: PDWORD;
  T: PByte;
  I: longword;
begin
  S := Source;
  T := Target;
  for I := 1 to Count do begin
    T^ := S^ and $ff;
    inc(T);
    T^ := (S^ shr 8) and $ff;
    inc(T);
    T^ := (S^ shr 16) and $ff;
    inc(T);
    T^ := (S^ shr 24) and $ff;
    inc(T);
    inc(S);
  end;
end;

procedure Transform(Buffer: pointer; var State: MD5State);
var
  a, b, c, d: DWORD;
  Block: MD5Block;
begin
  Encode(Buffer, @Block, 64);
  a := State[0];
  b := State[1];
  c := State[2];
  d := State[3];
  FF (a, b, c, d, Block[ 0],  7, $d76aa478);
  FF (d, a, b, c, Block[ 1], 12, $e8c7b756);
  FF (c, d, a, b, Block[ 2], 17, $242070db);
  FF (b, c, d, a, Block[ 3], 22, $c1bdceee);
  FF (a, b, c, d, Block[ 4],  7, $f57c0faf);
  FF (d, a, b, c, Block[ 5], 12, $4787c62a);
  FF (c, d, a, b, Block[ 6], 17, $a8304613);
  FF (b, c, d, a, Block[ 7], 22, $fd469501);
  FF (a, b, c, d, Block[ 8],  7, $698098d8);
  FF (d, a, b, c, Block[ 9], 12, $8b44f7af);
  FF (c, d, a, b, Block[10], 17, $ffff5bb1);
  FF (b, c, d, a, Block[11], 22, $895cd7be);
  FF (a, b, c, d, Block[12],  7, $6b901122);
  FF (d, a, b, c, Block[13], 12, $fd987193);
  FF (c, d, a, b, Block[14], 17, $a679438e);
  FF (b, c, d, a, Block[15], 22, $49b40821);
  GG (a, b, c, d, Block[ 1],  5, $f61e2562);
  GG (d, a, b, c, Block[ 6],  9, $c040b340);
  GG (c, d, a, b, Block[11], 14, $265e5a51);
  GG (b, c, d, a, Block[ 0], 20, $e9b6c7aa);
  GG (a, b, c, d, Block[ 5],  5, $d62f105d);
  GG (d, a, b, c, Block[10],  9,  $2441453);
  GG (c, d, a, b, Block[15], 14, $d8a1e681);
  GG (b, c, d, a, Block[ 4], 20, $e7d3fbc8);
  GG (a, b, c, d, Block[ 9],  5, $21e1cde6);
  GG (d, a, b, c, Block[14],  9, $c33707d6);
  GG (c, d, a, b, Block[ 3], 14, $f4d50d87);
  GG (b, c, d, a, Block[ 8], 20, $455a14ed);
  GG (a, b, c, d, Block[13],  5, $a9e3e905);
  GG (d, a, b, c, Block[ 2],  9, $fcefa3f8);
  GG (c, d, a, b, Block[ 7], 14, $676f02d9);
  GG (b, c, d, a, Block[12], 20, $8d2a4c8a);
  HH (a, b, c, d, Block[ 5],  4, $fffa3942);
  HH (d, a, b, c, Block[ 8], 11, $8771f681);
  HH (c, d, a, b, Block[11], 16, $6d9d6122);
  HH (b, c, d, a, Block[14], 23, $fde5380c);
  HH (a, b, c, d, Block[ 1],  4, $a4beea44);
  HH (d, a, b, c, Block[ 4], 11, $4bdecfa9);
  HH (c, d, a, b, Block[ 7], 16, $f6bb4b60);
  HH (b, c, d, a, Block[10], 23, $bebfbc70);
  HH (a, b, c, d, Block[13],  4, $289b7ec6);
  HH (d, a, b, c, Block[ 0], 11, $eaa127fa);
  HH (c, d, a, b, Block[ 3], 16, $d4ef3085);
  HH (b, c, d, a, Block[ 6], 23,  $4881d05);
  HH (a, b, c, d, Block[ 9],  4, $d9d4d039);
  HH (d, a, b, c, Block[12], 11, $e6db99e5);
  HH (c, d, a, b, Block[15], 16, $1fa27cf8);
  HH (b, c, d, a, Block[ 2], 23, $c4ac5665);
  II (a, b, c, d, Block[ 0],  6, $f4292244);
  II (d, a, b, c, Block[ 7], 10, $432aff97);
  II (c, d, a, b, Block[14], 15, $ab9423a7);
  II (b, c, d, a, Block[ 5], 21, $fc93a039);
  II (a, b, c, d, Block[12],  6, $655b59c3);
  II (d, a, b, c, Block[ 3], 10, $8f0ccc92);
  II (c, d, a, b, Block[10], 15, $ffeff47d);
  II (b, c, d, a, Block[ 1], 21, $85845dd1);
  II (a, b, c, d, Block[ 8],  6, $6fa87e4f);
  II (d, a, b, c, Block[15], 10, $fe2ce6e0);
  II (c, d, a, b, Block[ 6], 15, $a3014314);
  II (b, c, d, a, Block[13], 21, $4e0811a1);
  II (a, b, c, d, Block[ 4],  6, $f7537e82);
  II (d, a, b, c, Block[11], 10, $bd3af235);
  II (c, d, a, b, Block[ 2], 15, $2ad7d2bb);
  II (b, c, d, a, Block[ 9], 21, $eb86d391);
  inc(State[0], a);
  inc(State[1], b);
  inc(State[2], c);
  inc(State[3], d);
end;

procedure MD5Init(var Context: MD5Context);
begin
  with Context do begin
    State[0] := $67452301;
    State[1] := $efcdab89;
    State[2] := $98badcfe;
    State[3] := $10325476;
    Count[0] := 0;
    Count[1] := 0;
    ZeroMemory(@Buffer, SizeOf(MD5Buffer));
  end;
end;

procedure MD5Update(var Context: MD5Context; Input: pChar; Length: longword);
var
  Index: longword;
  PartLen: longword;
  I: longword;
begin
  with Context do begin
    Index := (Count[0] shr 3) and $3f;
    inc(Count[0], Length shl 3);
    if Count[0] < (Length shl 3) then inc(Count[1]);
    inc(Count[1], Length shr 29);
  end;
  PartLen := 64 - Index;
  if Length >= PartLen then begin
    CopyMemory(@Context.Buffer[Index], Input, PartLen);
    Transform(@Context.Buffer, Context.State);
    I := PartLen;
    while I + 63 < Length do begin
      Transform(@Input[I], Context.State);
      inc(I, 64);
    end;
    Index := 0;
  end else I := 0;
  CopyMemory(@Context.Buffer[Index], @Input[I], Length - I);
end;

procedure MD5Final(var Context: MD5Context; var Digest: MD5Digest);
var
  Bits: MD5CBits;
  Index: longword;
  PadLen: longword;
begin
  Decode(@Context.Count, @Bits, 2);
  Index := (Context.Count[0] shr 3) and $3f;
  if Index < 56 then PadLen := 56 - Index else PadLen := 120 - Index;
  MD5Update(Context, @PADDING, PadLen);
  MD5Update(Context, @Bits, 8);
  Decode(@Context.State, @Digest, 4);
  ZeroMemory(@Context, SizeOf(MD5Context));
end;

function MD5String(M: string): MD5Digest;
var
  Context: MD5Context;
begin
  MD5Init(Context);
  MD5Update(Context, pChar(M), length(M));
  MD5Final(Context, Result);
end;



function MD5File(N: string): MD5Digest;
var
  FileHandle: THandle;
  MapHandle: THandle;
  ViewPointer: pointer;
  Context: MD5Context;
begin
  MD5Init(Context);
  FileHandle := CreateFile(pChar(N), GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE,
    nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL or FILE_FLAG_SEQUENTIAL_SCAN, 0);
  if FileHandle <> INVALID_HANDLE_VALUE then try
    MapHandle := CreateFileMapping(FileHandle, nil, PAGE_READONLY, 0, 0, nil);
    if MapHandle <> 0 then try
      ViewPointer := MapViewOfFile(MapHandle, FILE_MAP_READ, 0, 0, 0);
      if ViewPointer <> nil then try
        MD5Update(Context, ViewPointer, GetFileSize(FileHandle, nil));
      finally
        UnmapViewOfFile(ViewPointer);
      end;
    finally
      CloseHandle(MapHandle);
    end;
  finally
    CloseHandle(FileHandle);
  end;
  MD5Final(Context, Result);
end;

function MD5Print(D: MD5Digest): string;
var
  I: byte;
const
  Digits: array[0..15] of char =
    ('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F');
begin
  Result := '';
  for I := 0 to 15 do Result := Result + Digits[(D[I] shr 4) and $0f] + Digits[D[I] and $0f];
end;


function MD5Match(D1, D2: MD5Digest): boolean;
var
  I: byte;
begin
  I := 0;
  Result := TRUE;
  while Result and (I < 16) do begin
    Result := D1[I] = D2[I];
    inc(I);
  end;
end;

function RivestStr(Str: string): string;
begin
  Result := MD5Print(MD5String(Str));
end;

function RivestFile(FileName: string): string;
begin
  Result := MD5Print(MD5File(FileName));
end;



end.

2 个答案:

答案 0 :(得分：6)

您遇到的是哈希8位Ansi数据与16位Unicode数据之间的区别。您的旧代码需要Ansi数据，而您的新代码则使用Unicode数据。散列是在原始字节上完成的，而不是在字符上完成的，所以你不会散列相同的数据，这就是你得到不同结果的原因。

Indy使用Delphi的默认String类型，在Delphi 2007及更早版本中为AnsiString，但在Delphi 2009及更高版本中为UnicodeString。

在散列Unicode字符串数据时，您需要先将数据转换为特定的字节编码，然后再对其进行散列。您的旧代码忽略了该步骤，因为它不是为了考虑Unicode而编写的，它假设正在使用AnsiString并按原样散列原始字符串数据。

TIdHashMessageDigest5.HashString...()方法有一个可选的ADestEncoding参数，因此您可以在对结果字节进行散列之前指定输入Unicode数据的所需字节编码，例如：

function MD5Hash(Value : String) : String;
var
  workHash : TIdHashMessageDigest5;
begin
  workHash := TIdHashMessageDigest5.Create;
  try
    // You can use whatever byte encoding you need. Indy's OSDefault
    // encoding is the same Ansi encoding used by AnsiString on Windows
    // (but is UTF-8 on other platforms). Note that converting Unicode
    // data to Ansi is a potentially lossy conversion, so you should
    // usually be using a loss-less encoding instead, such as UTF-8...
    //
    Result := workHash.HashStringAsHex(Value, IndyTextEncoding_OSDefault);
  finally
    FreeAndNil(workHash);
  end;
end;

如果您没有指定字节编码，则使用Indy的默认字节编码，默认设置为US-ASCII（您可以使用GIdDefaultTextEncoding中的全局IdGlobal变量进行更改单元）。

在Delphi 2007及更早版本中，string为AnsiString，输入字符串首先从Ansi转换为Unicode，然后再从Unicode转换为字节。因此，HashString...()方法还有一个可选的ASrcEncoding参数，如果它与操作系统的默认字符编码不同，您可以使用它来指定AnsiString使用的实际字符编码。

答案 1 :(得分：2)

问题是您的RivestStr功能旨在使用8位Ansi数据。 AnsiString和PAnsiChar是2009年之前Delphi版本中的默认字符串/字符类型。像柏林这样的新版Delphi版本现在使用16位Unicode字符串/字符作为默认值。

散列是在原始字节上完成的，因此在从8位字符串到16位Unicode字符串创建散列字符串时会得到不同的结果，即使它们都包含相同的可打印字符。

事实上，它的设计方式，当您使用现代Delphi版本（如Berlin）编译时，RivestStr()函数及其基础MD5String方法会向您返回错误的结果。

您可以通过在2009年之前的旧版Delphi版本和Delphi Berlin中制作相同的测试应用程序（相同的代码）来检查这一点，您将看到您得到的结果不同。

现在，如何解决您的问题？

在MD5单元中，您需要替换所有出现的：

  • string与AnsiString。

  • char与AnsiChar。

  • PChar与PAnsiChar。

唯一的例外是：

  • N方法

    • 的MD5File参数

  • pChar的{​​{1}}类型转换N。

如果您决定也更改这些内容，请不要忘记将CreateFile()调用替换为CreateFile()，以便将Ansi字符串作为给定文件名的输入。

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