求助将Delphi的加密解密算法写成C语言

只看该作者 · 2014-5-24 10:29

//加密关键字：key=“123”
//明码：1231adcd1234
//加密后，8FAF8FA7AC43E90F25151F0853
function TMainForm.EncryptString(Source, Key: string): string;  //加密
var
  KeyLen: integer;
  KeyPos: integer;
  Offset: integer;
  Dest: string;
  SrcPos: integer;
  SrcAsc: integer;
  Range: integer;
begin
  KeyLen := Length(Key);
  if KeyLen = 0 then
Key := 'delphi';
KeyPos := 0;
Range := 256;
randomize;
Offset := random(Range);
Dest := format('%1.2x', [Offset]);
for SrcPos := 1 to Length(Source) do
   begin
      SrcAsc := (Ord(Source[SrcPos]) + Offset) mod 255;

      if KeyPos < KeyLen then
      KeyPos := KeyPos + 1
      else
      KeyPos := 1;

   SrcAsc := SrcAsc xor Ord(Key[KeyPos]);
   Dest := Dest + format('%1.2x', [SrcAsc]);
   Offset := SrcAsc;
   end;
  result := Dest;
end;

function TMainForm.UnEncryptString(Source, Key: string): string; //解密
  var
KeyLen: integer;
KeyPos: integer;
Offset: integer;
Dest: string;
SrcPos: integer;
SrcAsc: integer;
TmpSrcAsc: integer;
begin
KeyLen := Length(Key);
if KeyLen = 0 then
   Key := 'delphi';
KeyPos := 0;
Offset := strtoint('$' + copy(Source, 1, 2));
SrcPos := 3;
repeat
   SrcAsc := strtoint('$' + copy(Source, SrcPos, 2));
   if KeyPos < KeyLen then
      KeyPos := KeyPos + 1
   else
      KeyPos := 1;

   TmpSrcAsc := SrcAsc xor Ord(Key[KeyPos]);
   if TmpSrcAsc <= Offset then
   TmpSrcAsc := 255 + TmpSrcAsc - Offset
   else
   TmpSrcAsc := TmpSrcAsc - Offset;

   Dest := Dest + chr(TmpSrcAsc);
   Offset := SrcAsc;
   SrcPos := SrcPos + 2;
until SrcPos >= Length(Source);
result := Dest;
end;

//我用C语言写的解密算法不对？请帮忙检查，谢谢.....
char a2x( char ch )
{
switch( ch )
{
case '1':
return 1;
case '2':
return 2;
case '3':
return 3;
case '4':
return 4;
case '5':
return 5;
case '6':
return 6;
case '7':
return 7;
case '8':
return 8;
case '9':
return 9;
case 'A':
case 'a':
return 10;
case 'B':
case 'b':
return 11;
case 'C':
case 'c':
return 12;
case 'D':
case 'd':
return 13;
case 'E':
case 'e':
return 14;
case 'F':
case 'f':
return 15;
default:
break;;
}
return 0;
}
void unEncrypt( char *source, int srcLen )
{
xdata char i = 0;
xdata char keyLen;
xdata char keyPos;
xdata char srcPos;
xdata char srcAsc;
xdata char tmpSrcAsc;
xdata char offset;
xdata char key[]    = "123";
xdata char dest[64] = { 0, };

keyPos = 0;
keyLen = strlen( key );
offset = ( a2x( source[0] ) << 4 ) | a2x( source[1] );

for( srcPos = 2; srcPos < srcLen; )
{
srcAsc    = ( a2x( source[srcPos] ) << 4 ) | a2x( source[srcPos + 1] );
tmpSrcAsc  = srcAsc ^ key[keyPos];

if( tmpSrcAsc <= offset )
{
tmpSrcAsc = 255 + tmpSrcAsc - offset;
}
else
{
tmpSrcAsc = tmpSrcAsc - offset;
}

dest[i++] = tmpSrcAsc;

offset = srcAsc;

srcPos += 2;
if( keyPos < keyLen )
{
keyLen++;
}
else
{
keyPos = 0;
}
}
}

求助将Delphi的加密解密算法写成C语言

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