#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <unistd.h>
#include <arpa/inet.h>
/* SSL includes */
#include <openssl/ssl.h>
#include <openssl/err.h>

int main(int argc, char *argv[]) {
    SSL_METHOD *my_ssl_method;
    SSL_CTX *my_ssl_ctx;
    SSL *my_ssl;
    int my_fd,client_fd;
    struct sockaddr_in server, client;
    int client_size;
    int error = 0, wrote = 0;
    char buffer[] = "Hello there! Welcome to the SSL test server.\n\n";

SSL_library_init(); 
    SSL_load_error_strings();

    my_ssl_method = TLSv1_server_method();  

    if((my_ssl_ctx = SSL_CTX_new(my_ssl_method)) == NULL) {
        ERR_print_errors_fp(stderr);
        exit(1);
    }

    SSL_CTX_use_certificate_file(my_ssl_ctx,"server.pem",SSL_FILETYPE_PEM); 
    SSL_CTX_use_PrivateKey_file(my_ssl_ctx,"server.pem",SSL_FILETYPE_PEM);

    if(!SSL_CTX_check_private_key(my_ssl_ctx)) {
        fprintf(stderr,"Private key does not match certificate\n");
        exit(1);
    }

    my_fd = socket(PF_INET, SOCK_STREAM, 0);        
    server.sin_family = AF_INET;
    server.sin_port = htons(5353);
    server.sin_addr.s_addr = INADDR_ANY;
    bind(my_fd, (struct sockaddr *)&server, sizeof(server));
    listen(my_fd, 5);

    for(;;) {
        client_size = sizeof(client);
        bzero(&client,sizeof(client));
        client_fd = accept(my_fd, (struct sockaddr *)&client, (socklen_t *)&client_size);

        if((my_ssl = SSL_new(my_ssl_ctx)) == NULL) {
            ERR_print_errors_fp(stderr);
            exit(1);
        }

        SSL_set_fd(my_ssl,client_fd);

        if(SSL_accept(my_ssl) <= 0) {
            ERR_print_errors_fp(stderr);
            exit(1);
        }

        printf("Connection made with [version,cipher]: [%s,%s]\n",SSL_get_version(my_ssl),SSL_get_cipher(my_ssl));

        for(wrote = 0; wrote < strlen(buffer); wrote += error) {
            error = SSL_write(my_ssl,buffer+wrote,strlen(buffer)-wrote);

            if(error <= 0)
                break;
        }
        
        SSL_shutdown(my_ssl);

        SSL_free(my_ssl);
        close(client_fd);
    }

    SSL_CTX_free(my_ssl_ctx);

    return 0;
}