BIO_ssl_shutdown

This SSL/TLS client example, attempts to retrieve a page from an SSL/TLS web server. The I/O routines are identical to those of the unencrypted example in BIO_s_connect(3).

 BIO *sbio, *out;
 int len;
 char tmpbuf[1024];
 SSL_CTX *ctx;
 SSL *ssl;

 ERR_load_crypto_strings();
 ERR_load_SSL_strings();
 OpenSSL_add_all_algorithms();

 /* We would seed the PRNG here if the platform didn't
  * do it automatically
  */

 ctx = SSL_CTX_new(SSLv23_client_method());

 /* We'd normally set some stuff like the verify paths and
  * mode here because as things stand this will connect to
  * any server whose certificate is signed by any CA.
  */

 sbio = BIO_new_ssl_connect(ctx);

 BIO_get_ssl(sbio, &ssl);

 if(!ssl) {
   fprintf(stderr, "Can't locate SSL pointer\n");
   /* whatever ... */
 }

 /* Don't want any retries */
 SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY);

 /* We might want to do other things with ssl here */

 BIO_set_conn_hostname(sbio, "localhost:https");

 out = BIO_new_fp(stdout, BIO_NOCLOSE);
 if(BIO_do_connect(sbio) <= 0) {
        fprintf(stderr, "Error connecting to server\n");
        ERR_print_errors_fp(stderr);
        /* whatever ... */
 }

 if(BIO_do_handshake(sbio) <= 0) {
        fprintf(stderr, "Error establishing SSL connection\n");
        ERR_print_errors_fp(stderr);
        /* whatever ... */
 }

 /* Could examine ssl here to get connection info */

 BIO_puts(sbio, "GET / HTTP/1.0\n\n");
 for(;;) {      
        len = BIO_read(sbio, tmpbuf, 1024);
        if(len <= 0) break;
        BIO_write(out, tmpbuf, len);
 }
 BIO_free_all(sbio);
 BIO_free(out);

Here is a simple server example. It makes use of a buffering BIO to allow lines to be read from the SSL BIO using BIO_gets. It creates a pseudo web page containing the actual request from a client and also echoes the request to standard output.

 BIO *sbio, *bbio, *acpt, *out;
 int len;
 char tmpbuf[1024];
 SSL_CTX *ctx;
 SSL *ssl;

 ERR_load_crypto_strings();
 ERR_load_SSL_strings();
 OpenSSL_add_all_algorithms();

 /* Might seed PRNG here */

 ctx = SSL_CTX_new(SSLv23_server_method());

 if (!SSL_CTX_use_certificate_file(ctx,"server.pem",SSL_FILETYPE_PEM)
        || !SSL_CTX_use_PrivateKey_file(ctx,"server.pem",SSL_FILETYPE_PEM)
        || !SSL_CTX_check_private_key(ctx)) {

        fprintf(stderr, "Error setting up SSL_CTX\n");
        ERR_print_errors_fp(stderr);
        return 0;
 }

 /* Might do other things here like setting verify locations and
  * DH and/or RSA temporary key callbacks
  */

 /* New SSL BIO setup as server */
 sbio=BIO_new_ssl(ctx,0);

 BIO_get_ssl(sbio, &ssl);

 if(!ssl) {
   fprintf(stderr, "Can't locate SSL pointer\n");
   /* whatever ... */
 }

 /* Don't want any retries */
 SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY);

 /* Create the buffering BIO */

 bbio = BIO_new(BIO_f_buffer());

 /* Add to chain */
 sbio = BIO_push(bbio, sbio);

 acpt=BIO_new_accept("4433");

 /* By doing this when a new connection is established
  * we automatically have sbio inserted into it. The
  * BIO chain is now 'swallowed' by the accept BIO and
  * will be freed when the accept BIO is freed. 
  */
 
 BIO_set_accept_bios(acpt,sbio);

 out = BIO_new_fp(stdout, BIO_NOCLOSE);

 /* Setup accept BIO */
 if(BIO_do_accept(acpt) <= 0) {
        fprintf(stderr, "Error setting up accept BIO\n");
        ERR_print_errors_fp(stderr);
        return 0;
 }

 /* Now wait for incoming connection */
 if(BIO_do_accept(acpt) <= 0) {
        fprintf(stderr, "Error in connection\n");
        ERR_print_errors_fp(stderr);
        return 0;
 }

 /* We only want one connection so remove and free
  * accept BIO
  */

 sbio = BIO_pop(acpt);

 BIO_free_all(acpt);

 if(BIO_do_handshake(sbio) <= 0) {
        fprintf(stderr, "Error in SSL handshake\n");
        ERR_print_errors_fp(stderr);
        return 0;
 }

 BIO_puts(sbio, "HTTP/1.0 200 OK\r\nContent-type: text/plain\r\n\r\n");
 BIO_puts(sbio, "\r\nConnection Established\r\nRequest headers:\r\n");
 BIO_puts(sbio, "--------------------------------------------------\r\n");

 for(;;) {
        len = BIO_gets(sbio, tmpbuf, 1024);
        if(len <= 0) break;
        BIO_write(sbio, tmpbuf, len);
        BIO_write(out, tmpbuf, len);
        /* Look for blank line signifying end of headers*/
        if((tmpbuf[0] == '\r') || (tmpbuf[0] == '\n')) break;
 }

 BIO_puts(sbio, "--------------------------------------------------\r\n");
 BIO_puts(sbio, "\r\n");

 /* Since there is a buffering BIO present we had better flush it */
 BIO_flush(sbio);

 BIO_free_all(sbio);

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