/* serv.cpp  -  Minimal ssleay server for Unix   30.9.1996, Sampo Kellomaki <sampo@iki.fi> *//* mangled to work with SSLeay-0.9.0b and OpenSSL 0.9.2b   Simplified to be even more minimal   12/98 - 4/99 Wade Scholine <wades@mail.cybg.com> */#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <memory.h>#include <errno.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <netdb.h>#include <openssl/rsa.h>       /* SSLeay stuff */#include <openssl/crypto.h>#include <openssl/x509.h>#include <openssl/pem.h>#include <openssl/ssl.h>#include <openssl/err.h>/* define HOME to be dir for key and cert files... */#define HOME "./"/* Make these what you want for cert & key files */#define CERTF  HOME "foo-cert.pem"#define KEYF  HOME  "foo-cert.pem"#define CHK_NULL(x) if ((x)==NULL) exit (1)#define CHK_ERR(err,s) if ((err)==-1) { perror(s); exit(1); }#define CHK_SSL(err) if ((err)==-1) { ERR_print_errors_fp(stderr); exit(2); }void main (){  int err;  int listen_sd;  int sd;  struct sockaddr_in sa_serv;  struct sockaddr_in sa_cli;  size_t client_len;  SSL_CTX* ctx;  SSL*     ssl;  X509*    client_cert;  char*    str;  char     buf [4096];  SSL_METHOD *meth;    /* SSL preliminaries. We keep the certificate and key with the context. */  SSL_load_error_strings();  SSLeay_add_ssl_algorithms();  meth = SSLv23_server_method();  ctx = SSL_CTX_new (meth);  if (!ctx) {    ERR_print_errors_fp(stderr);    exit(2);  }    if (SSL_CTX_use_certificate_file(ctx, CERTF, SSL_FILETYPE_PEM) <= 0) {    ERR_print_errors_fp(stderr);    exit(3);  }  if (SSL_CTX_use_PrivateKey_file(ctx, KEYF, SSL_FILETYPE_PEM) <= 0) {    ERR_print_errors_fp(stderr);    exit(4);  }  if (!SSL_CTX_check_private_key(ctx)) {    fprintf(stderr,"Private key does not match the certificate public key\n");    exit(5);  }  /* ----------------------------------------------- */  /* Prepare TCP socket for receiving connections */  listen_sd = socket (AF_INET, SOCK_STREAM, 0);   CHK_ERR(listen_sd, "socket");    memset (&sa_serv, '\0', sizeof(sa_serv));  sa_serv.sin_family      = AF_INET;  sa_serv.sin_addr.s_addr = INADDR_ANY;  sa_serv.sin_port        = htons (1111);          /* Server Port number */    err = bind(listen_sd, (struct sockaddr*) &sa_serv,	     sizeof (sa_serv));                   CHK_ERR(err, "bind");	       /* Receive a TCP connection. */	       err = listen (listen_sd, 5);                    CHK_ERR(err, "listen");    client_len = sizeof(sa_cli);  sd = accept (listen_sd, (struct sockaddr*) &sa_cli, &client_len);  CHK_ERR(sd, "accept");  close (listen_sd);  printf ("Connection from %lx, port %x\n",	  sa_cli.sin_addr.s_addr, sa_cli.sin_port);    /* ----------------------------------------------- */  /* TCP connection is ready. Do server side SSL. */  ssl = SSL_new (ctx);                           CHK_NULL(ssl);  SSL_set_fd (ssl, sd);  err = SSL_accept (ssl);                        CHK_SSL(err);    /* Get the cipher - opt */    printf ("SSL connection using %s\n", SSL_get_cipher (ssl));    /* Get client's certificate (note: beware of dynamic allocation) - opt */  client_cert = SSL_get_peer_certificate (ssl);  if (client_cert != NULL) {    printf ("Client certificate:\n");        str = X509_NAME_oneline (X509_get_subject_name (client_cert), 0, 0);    CHK_NULL(str);    printf ("\t subject: %s\n", str);    OPENSSL_free (str);        str = X509_NAME_oneline (X509_get_issuer_name  (client_cert), 0, 0);    CHK_NULL(str);    printf ("\t issuer: %s\n", str);    OPENSSL_free (str);        /* We could do all sorts of certificate verification stuff here before       deallocating the certificate. */        X509_free (client_cert);  } else    printf ("Client does not have certificate.\n");  /* DATA EXCHANGE - Receive message and send reply. */  err = SSL_read (ssl, buf, sizeof(buf) - 1);                   CHK_SSL(err);  buf[err] = '\0';  printf ("Got %d chars:'%s'\n", err, buf);    err = SSL_write (ssl, "I hear you.", strlen("I hear you."));  CHK_SSL(err);  /* Clean up. */  close (sd);  SSL_free (ssl);  SSL_CTX_free (ctx);}/* EOF - serv.cpp */