int BIO_ssl_copy_session_id(BIO *to,BIO *from);
void BIO_ssl_shutdown(BIO *bio);
+ #define BIO_do_handshake(b) BIO_ctrl(b,BIO_C_DO_STATE_MACHINE,0,NULL)
+
=head1 DESCRIPTION
BIO_f_ssl() returns the SSL BIO method. This is a filter BIO which
SSL I/O.
I/O performed on an SSL BIO communicates using the SSL protocol with
-the SSLs read and write BIOs.
+the SSLs read and write BIOs. If an SSL connection is not established
+then an attempt is made to establish one on the first I/O call.
If a BIO is appended to an SSL BIO using BIO_push() it is automatically
used as the SSL BIOs read and write BIOs.
least 512 bytes.
BIO_set_ssl_renegotiate_timeout() sets the renegotiate timeout to
-B<seconds>. When the renegotiate timeout elapses the sesssion is
+B<seconds>. When the renegotiate timeout elapses the session is
automatically renegotiated.
BIO_get_num_renegotiates() returns the total number of session
chain and calling SSL_shutdown() on its internal SSL
pointer.
+BIO_do_handshake() attempts to complete an SSL handshake on the
+supplied BIO and establish the SSL connection. It returns 1
+if the connection was established successfully. A zero or negative
+value is returned if the connection could not be established, the
+call BIO_should_retry() should be used for non blocking connect BIOs
+to determine if the call should be retried. If an SSL connection has
+already been established this call has no effect.
+
=head1 NOTES
SSL BIOs are exceptional in that if the underlying transport
on the BIO returned by BIO_new_ssl_connect() without having
to locate the connect BIO first.
+Applications do not have to call BIO_do_handshake() but may wish
+to do so to separate the handshake process from other I/O
+processing.
+
=head1 RETURN VALUES
TBA
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
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_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);
+
+=head1 BUGS
+
+In OpenSSL versions before 1.0.0 the BIO_pop() call was handled incorrectly,
+the I/O BIO reference count was incorrectly incremented (instead of
+decremented) and dissociated with the SSL BIO even if the SSL BIO was not
+explicitly being popped (e.g. a pop higher up the chain). Applications which
+included workarounds for this bug (e.g. freeing BIOs more than once) should
+be modified to handle this fix or they may free up an already freed BIO.
+
=head1 SEE ALSO
TBA