=====rnsget=====

Get random numbers from [[RNS]] (random number server).

%%
usage: rnsget <server-ip> -n <number> -f <format> -d <delimiter>

Programm connects to a random number server (RNS) to request random numbers.
Andreas Tobola (http://tnotes.de/RNS)

General options:
		-h  Print this help
		-n  Get n random bytes from server (default: n = 1)
		-d  Delimiter e.g. ; . (default: space)
		-i  Return server info string

Format options:
		-u  unsigned 16 bit integer format like rand() in C (default)
		-x  hex format
		-b  byte stream like /dev/random at Linux systems
%%



%%(c;;rnsget.c)
/*
 *   RNSGET for access to Random Number Server 
 *   http://www.tnotes.de/rnsget
 *   Andreas Tobola
 *   2013-03-12
 *   
 */

#include <stdio.h>
#include <stdlib.h>

#include <ctype.h>
#include <unistd.h>

#ifdef _WIN32
	#include <winsock2.h>
	#include <io.h>
#else
	#include <netdb.h>
	#include <unistd.h>
	#include <netinet/in.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <arpa/inet.h>
#endif


#include "rnsget_private.h"


#define OF_UNSIGNED16 0
#define OF_HEX        1
#define OF_BYTESTREAM 2
#define OF_CHAR       3

#define MAX_NUM_OF_RAND_BYTES (1024*10)


SOCKET s;
struct sockaddr_in servaddr;
struct sockaddr_in cliaddr;
unsigned char sendline[20];
unsigned char recvline[MAX_NUM_OF_RAND_BYTES];
WSADATA wsa;


char *cDelimiter = NULL;
int outputFormat = OF_UNSIGNED16;
int requestInfo = 0;


// Prototypes
void requestNumbers(unsigned int randNumCount);
void showHelp(char * progName);



int main(int argc, char *argv[])
{

	  
   int index;
   int c;
   int n;
   
   unsigned long randNumTotalCount = 1;
	 
   opterr = 0;
   
   servaddr.sin_family = AF_INET;
   servaddr.sin_addr.s_addr=inet_addr(argv[1]); // we need to save this before getopt() ist called
   servaddr.sin_port=htons(4224);
	  
   
 
   while ((c = getopt (argc, argv, "vhn:d:xubic")) != -1)
	 switch (c)
	 {
	   case 'h':
		 showHelp(argv[0]);   
		 exit(0);
		 break;
		 
	   case 'n':
		 randNumTotalCount = atol(optarg);
		 if (randNumTotalCount == 0)
			 randNumTotalCount = 1;
		 break;         
		 
	   case 'd':
		 cDelimiter = optarg;
		 break;
		 
	   case 'x':
		 outputFormat = OF_HEX;
		 break;         
		 
	   case 'b':
		 outputFormat = OF_BYTESTREAM;
		 break;         
		 
	   case 'u':
		 outputFormat = OF_UNSIGNED16;
		 break;         
		 
	   case 'c':
		 outputFormat = OF_CHAR;
		 break;      
		 
	   case 'i':
		 requestInfo = 1;
		 break;                

	   case 'v':
		 printf("%s %s",argv[0], VER_STRING);
		 exit(0);
		 break;
	   
	   default:
		   if (optopt == 'n' || optopt == 'd')
			   fprintf (stderr, "Option -%s requires an argument.\n", optopt);
			 else if (isprint (optopt))
			   fprintf (stderr, "Unknown option `-%c'.\n", optopt);
			 else
			   fprintf (stderr, "Unknown option character `\\x%x'.\n", optopt);
	
			 exit(EXIT_FAILURE);

	}
	   
	   
   if (cDelimiter == NULL)
	   cDelimiter = " ";
 
   //printf ("randNumCount = %u, cDelimiter = %s\n", randNumCount, cDelimiter);
	


   if (argc < 2)
   {
	  printf("please define at least a server adress: rnsget <IP address>\nuse rnsget -h for help.\n");
	  exit(EXIT_FAILURE);
   }

	if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)
	{
		printf("Failed. Error Code : %d", WSAGetLastError());
		exit(EXIT_FAILURE);
	}

	//Create a socket
	if((s = socket(AF_INET , SOCK_DGRAM , 0 )) == INVALID_SOCKET)
	{
		printf("Could not create socket : %d" , WSAGetLastError());
		exit(EXIT_FAILURE);
	}
	
	// Set Timeout for recv call
	unsigned int iTimeout = 5000; // Millisekunden
	if(     
	 setsockopt( s, SOL_SOCKET, SO_RCVTIMEO, (const char *)&iTimeout,
						sizeof(iTimeout) )
	   )
	{    
		printf("Could not set timeout : %d" , WSAGetLastError());
		exit(EXIT_FAILURE);
	}

   //bzero(&servaddr,sizeof(servaddr));



   //Bind
   /*if( bind(s ,(struct sockaddr *)&servaddr , sizeof(servaddr)) == SOCKET_ERROR)
	{
		printf("Bind failed with error code : %d" , WSAGetLastError());
		exit(EXIT_FAILURE);
   }*/


   if (requestInfo==1)
   {
		// Request server info
		sendto(s,"reqI",4,0,(struct sockaddr *)&servaddr,sizeof(servaddr));
	  
		n = recvfrom(s,recvline,MAX_NUM_OF_RAND_BYTES,0,NULL,NULL);
		recvline[n] = 0;        
		puts("\n");
		puts(recvline);
	  
	}
	else
	{
		const unsigned int serverBufferSize = 1024;
		unsigned int multiRequestCount;
		unsigned int leftCount;
		unsigned int k;
		
		if (outputFormat == OF_UNSIGNED16)
		{
		   if (randNumTotalCount % 2 == 1)
			   randNumTotalCount++;
		}
		
		
		multiRequestCount = randNumTotalCount / serverBufferSize;
		leftCount = randNumTotalCount % serverBufferSize;
		
		//printf("%u  %u\n\n",multiRequestCount,leftCount);

		for (k=0;k<multiRequestCount;k++)
		{
		   requestNumbers(serverBufferSize);
		}
		// order the left numbers 
		requestNumbers(leftCount);
		   
		   

	}
	   



 
   closesocket(s);
   WSACleanup();  
   puts("\n"); 	
   	
   return 0;

}



/**
 *
 *
 */
void requestNumbers(unsigned int randNumCount)
{
	 
		int n;

		//printf("*** %u ***",randNumCount);

		if (randNumCount == 0) 
		{
				return;
		}
		
		sendline[0] = 'r';
		sendline[1] = 'e';
		sendline[2] = 'q';
		sendline[3] = 'R';
		sendline[4] = (unsigned char)(randNumCount & 0xFF);
		sendline[5] = (unsigned char)((randNumCount>>8) & 0xFF);                              
		// Request random numbers
		sendto(s, sendline, 6, 0, (struct sockaddr *)&servaddr,sizeof(servaddr));

		n = recvfrom(s,recvline, MAX_NUM_OF_RAND_BYTES,0,NULL,NULL);
		
		//printf("\n\n[[[%d]]]\n\n",n);
		
	
		
		if (n>0)
		{
		   unsigned int k;
		   //printf("%d bytes\n", n);
		   if (outputFormat == OF_HEX)
		   {             
				for (k=0;k<n;k++)
				{
					printf("%02x%s",recvline[k],cDelimiter);
				}
		   }
		   else if (outputFormat == OF_BYTESTREAM)
		   {
				for (k=0;k<n;k++)
				{
					putc(recvline[k],stdout);
				}
		   }
		   else if (outputFormat == OF_UNSIGNED16)
		   {
				unsigned int randInt;
				for (k=0;k<n;k+=2)
				{
					randInt = (unsigned int)(recvline[k]);
					randInt <<= 8;
					randInt |= (unsigned int)(recvline[k+1]);                    
					printf("%u%s",randInt,cDelimiter);
				}                
		   }
		   else if (outputFormat == OF_CHAR)
		   {
				for (k=0;k<n;k++)
				{
					printf("%u%s",recvline[k],cDelimiter);
				}                
		   }
		   
		}
		else
		{
			puts("Error: 0 bytes recived from server. Check IP adress.");
			exit(EXIT_FAILURE);
		}
		//fputs(recvline,stdout);
}





void showHelp(char * progName)
{
   printf("\nusage: %s <server-ip> -n <number> -f <format> -d <delimiter>\n\n"\
		  "Programm connects to a random number server (RNS) to request random numbers.\n"\
		  "Version: %s\n"\
		  "Andreas Tobola (http://tnotes.de/rnsget)\n"\
		  "\n"\          
		  "General options:\n"\
		  "\t-h  Print this help\n"\
		  "\t-n  Get n random bytes from server (default: n = 1)\n"\
		  "\t-d  Delimiter e.g. ; . (default: space)\n"\
		  "\t-i  Return server info string\n"\
		  "\t-v  return version string\n"\
		  "\n"\          
		  "Format options:\n"\
		  "\t-u  unsigned integer (16 bit) format like rand() in C (default)\n "\
		  "\t-c  unsigned char (8 bit) integer format\n "\
		  "\t-x  hex (8 bit) format\n "\
		  "\t-b  byte stream (8 bit) like /dev/random at Linux systems \n"\
		  , progName, VER_STRING);

}

%%


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