/* FFFTPのパスワード保存・読み出し処理 ver.1.96dより */

/*----- パスワードを暗号化する ------------------------------------------------
*
*	Parameter
*		char *Str : パスワード
*		kchar *Buf : 暗号化したパスワードを格納するバッファ
*
*	Return Value
*		なし
*----------------------------------------------------------------------------*/

static void EncodePassword(char *Str, char *Buf)
{
	unsigned char *Get;
	unsigned char *Put;
	int Rnd;
	int Ch;

	srand((unsigned)time(NULL));

	Get = (unsigned char *)Str;
	Put = (unsigned char *)Buf;
	while(*Get != NUL)
	{
		Rnd = rand() % 3;
		Ch = ((int)*Get++) << Rnd;
		Ch = (unsigned char)Ch | (unsigned char)(Ch >> 8);
		*Put++ = 0x40 | ((Rnd & 0x3) << 4) | (Ch & 0xF);
		*Put++ = 0x40 | ((Ch >> 4) & 0xF);
		if((*(Put-2) & 0x1) != 0)
			*Put++ = (rand() % 62) + 0x40;
	}
	*Put = NUL;
	return;
}


/*----- パスワードの暗号化を解く ----------------------------------------------
*
*	Parameter
*		char *Str : 暗号化したパスワード
*		kchar *Buf : パスワードを格納するバッファ
*
*	Return Value
*		なし
*----------------------------------------------------------------------------*/

static void DecodePassword(char *Str, char *Buf)
{
	unsigned char *Get;
	unsigned char *Put;
	int Rnd;
	int Ch;

	Get = (unsigned char *)Str;
	Put = (unsigned char *)Buf;
	while(*Get != NUL)
	{
		Rnd = ((unsigned int)*Get >> 4) & 0x3;
		Ch = (*Get & 0xF) | ((*(Get+1) & 0xF) << 4);
		Ch <<= 8;
		if((*Get & 0x1) != 0)
			Get++;
		Get += 2;
		Ch >>= Rnd;
		Ch = (Ch & 0xFF) | ((Ch >> 8) & 0xFF);
		*Put++ = Ch;
	}
	*Put = NUL;
	return;
}