/*	
 *	Demonstration TLS client
 *
 *       Compile with
 *
 *       gcc -Wall -o tls_client tls_client.c -L/usr/lib -lssl -lcrypto
 *
 *       Execute with
 *
 *       ./tls_client <server_INET_address> <port> <client message string>
 *
 *       Generate certificate with 
 *
 *       openssl req -x509 -nodes -days 365 -newkey rsa:1024 -keyout tls_demonstration_cert.pem -out tls_demonstration_cert.pem
 *
 *	 Developed for Intel Edison IoT Curriculum by UCLA WHI
 */
#include <arpa/inet.h>
#include <errno.h>
#ifndef __VMS
#include <malloc.h>
#endif
#include <netdb.h>
#include <netinet/in.h>
#include <net/if.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <resolv.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <time.h>
#include <unistd.h>

#define BUFSIZE 1024
#define AVERAGE_HEART_RATE 70.0

double generate_random_number(double lower, double upper);
char * get_ip_addr();
int open_port(const char *server_name, int server_port);
SSL_CTX *initialize_client_CTX(void);
void display_server_certificate(SSL * ssl);