Hvis der skal være sikkerhed kan du sende ham et link hvori der indgår en MD5-nøgle (dvs. den rigtige nøgle konverteret til 32 '0'..'F' tegn). MD5-nøglen er en sekundær nøgle til beskedden og gemmes altså sideløbende. Man kan stadig angive en anden
Lad være med at køre primærnøglen gennem en MD5-generator. Skal man kigge i databasen kan man bare lave et lille program der løber mulige nøgler igennem indtil man støder på en MD5 der er ens med den du har lavet. Derefter kan man sagtens kigge i andre records. Brug en timestamp eller lignende (eller støj fra rummet ligesom NSA)
.. hvad angår resten af din mail: Jeg forstår det ikke.
Paster her den unit jeg bruger.
// -----------------------------------------------------------------------------------------------
//
// MD5 Message-Digest for Delphi 4
//
// Delphi 4 Unit implementing the
// RSA Data Security, Inc. MD5 Message-Digest Algorithm
//
// Implementation of Ronald L. Rivest's RFC 1321
//
// Copyright © 1997-1999 Medienagentur Fichtner & Meyer
// Written by Matthias Fichtner
//
// -----------------------------------------------------------------------------------------------
// See RFC 1321 for RSA Data Security's copyright and license notice!
// -----------------------------------------------------------------------------------------------
//
// 14-Jun-97 mf Implemented MD5 according to RFC 1321 RFC 1321
// 16-Jun-97 mf Initial release of the compiled unit (no source code) RFC 1321
// 28-Feb-99 mf Added MD5Match function for comparing two digests RFC 1321
// 13-Sep-99 mf Reworked the entire unit RFC 1321
// 17-Sep-99 mf Reworked the "Test Driver" project RFC 1321
// 19-Sep-99 mf Release of sources for MD5 unit and "Test Driver" project RFC 1321
// 16-Feb-07 hrc Added support for streaming
//
// -----------------------------------------------------------------------------------------------
// The latest release of md5.pas will always be available from
// the distribution site at:
http://www.fichtner.net/delphi/md5/// -----------------------------------------------------------------------------------------------
// Please send questions, bug reports and suggestions
// regarding this code to: mfichtner@fichtner-meyer.com
// -----------------------------------------------------------------------------------------------
// This code is provided "as is" without express or
// implied warranty of any kind. Use it at your own risk.
// -----------------------------------------------------------------------------------------------
unit UMD5;
// -----------------------------------------------------------------------------------------------
interface
// -----------------------------------------------------------------------------------------------
uses
Windows, 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(const aString: string): MD5Digest;
function MD5File(const aFilename: string): MD5Digest;
function MD5Stream(const aMemoryStream : TMemoryStream) : MD5Digest;
function MD5Print(const aDigest: MD5Digest): string;
function MD5Match(const aDigest1, aDigest2: MD5Digest): boolean;
// -----------------------------------------------------------------------------------------------
implementation
// -----------------------------------------------------------------------------------------------
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
);
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;
// -----------------------------------------------------------------------------------------------
// Encode Count bytes at Source into (Count / 4) DWORDs at Target
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;
// Decode Count DWORDs at Source into (Count * 4) Bytes at Target
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;
// Transform State according to first 64 bytes at Buffer
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;
// -----------------------------------------------------------------------------------------------
// Initialize given Context
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;
// Update given Context to include Length bytes of Input
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;
// Finalize given Context, create Digest and zeroize Context
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;
// -----------------------------------------------------------------------------------------------
// Create digest of given Message
function MD5String(const aString: string): MD5Digest;
var
Context: MD5Context;
begin
MD5Init(Context);
MD5Update(Context, pChar(aString), length(aString));
MD5Final(Context, Result);
end;
// Create digest of file with given Name
function MD5File(const aFilename: string): MD5Digest;
var
FileHandle: THandle;
MapHandle: THandle;
ViewPointer: pointer;
Context: MD5Context;
begin
MD5Init(Context);
FileHandle := CreateFile(pChar(aFilename),
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 assigned(ViewPointer) 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 MD5Stream(const aMemoryStream : TMemoryStream) : MD5Digest;
var
Context: MD5Context;
begin
MD5Init(Context);
MD5Update(Context, aMemoryStream.Memory, aMemoryStream.Size);
MD5Final(Context, Result);
end;
// Create hex representation of given Digest
function MD5Print(const aDigest: 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[(aDigest[I] shr 4) and $0f] + Digits[aDigest[I] and $0f];
end;
// -----------------------------------------------------------------------------------------------
// Compare two Digests
function MD5Match(const aDigest1, aDigest2: MD5Digest): boolean;
var
I: byte;
begin
I := 0;
Result := TRUE;
while Result and (I < 16) do
begin
Result := aDigest1[I] = aDigest2[I];
inc(I);
end;
end;
end.