Random string generation not working fine?

[vjshankwar]

Hi all,

i m generating a random string,but its give same result when i generate these.

means i generate 5 different string than each and every time these 5 string are same as previously generated.

CString Generate_Str()
{
	int		m_iLength=5;
	BOOL	m_bLowercase=true;
	BOOL	m_bNumbers=true;
	BOOL	m_bSymbols=false;
	BOOL	m_bUppercase=true;
	CString	String="";
 
	
 
		int gen_len;  
		CString pword="";
		char possibles[77] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-+.,";
 
		for ( gen_len=0; gen_len < m_iLength; gen_len++ )
		{
			int todo;
 
			bool decided = false;
			do
			{
				int rand_me; 
				rand_me = rand() % 4;
 
				if ( (rand_me == 0) && (m_bLowercase == TRUE) ){
						todo = 0;
						decided = TRUE;
					}
					if ( (rand_me == 1) && (m_bUppercase == TRUE) ){
						todo = 1;
						decided = TRUE;
					}
					if ( (rand_me == 2) && (m_bNumbers == TRUE) ){
						todo = 2;
						decided = TRUE;
					}
					if ( (rand_me == 3) && (m_bSymbols == TRUE) ){
						todo = 3;
						decided = TRUE;
					}
 
			}while ( decided != TRUE );
			
 
			char value='a';
			switch (todo) 
			{
				case 0 :
					//Lower Letters
					value = possibles[ (rand() % 26) ];
					break;
				case 1 :
					//Cap Letters
					value = possibles[ (rand() % 26) + 26 ];
					break;
				case 2 :
					//Numbers
					value = possibles[ (rand() % 10) + 52 ];
					break;
				case 3 :
					//Symbols
					value = possibles[ (rand() % 14) + 63 ];
					break;
				default:
					
					break;
			}
			pword = pword + value;
		String= pword;
	
 
	return String;
}
 
//Alwayz give this
//=================
HOU84
NFX7V
CGIK1
9F33K
PEGRV

i want each time generate a new and different string.

please help me for this.

thanks in advance.

[SkyNetTo]

have you used srand() at the top of the program?

[Eri523]

Also please note that rand() isn't really suitable for cryptographic purposes (unless it's toy cryptography) what it looks like you want to use it for. There are better alternatives both in the Windows API (IIRC) and the C++0x standard library extensions.