windows password generator

gistfile1.cpp

#include <windows.h>
#include <stdio.h>

#pragma comment(lib, "Advapi32")

const int  CorpusSize = 26 * 2 + 10;
const char	Corpus[CorpusSize + 1] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

int main(int argc, char** argv)
{
	const int nChars = 30;
	HCRYPTPROV	crypt;
	byte		buf[nChars];
	char		result[nChars + 1];

	if ( !CryptAcquireContext( &crypt, NULL, NULL, PROV_RSA_AES, CRYPT_SILENT ) )
	{
		if ( !CryptAcquireContext( &crypt, NULL, NULL, PROV_RSA_AES, CRYPT_NEWKEYSET | CRYPT_SILENT ) )
		{
			printf( "CryptAcquireContext error (%d)\n", GetLastError() );
			return 1;
		}
	}

	memset( buf, 0, sizeof(buf) );
	if ( CryptGenRandom( crypt, sizeof(buf), buf ) )
	{
		for ( int i = 0; i < nChars; i++ )
			result[i] = Corpus[buf[i] % CorpusSize];
		result[nChars] = 0;
		printf( "%s\n", result );
	}
	else
	{
		printf( "CryptGenRandom error %d\n", GetLastError() );
	}

	CryptReleaseContext( crypt, 0 );

	return result[0] != 0;
}