Update build for OpenSSL-1.0.0a.
[dragonfly.git] / secure / lib / libcrypto / man / BIO_f_ssl.3
... / ...
CommitLineData
1.\" Automatically generated by Pod::Man 2.23 (Pod::Simple 3.14)
2.\"
3.\" Standard preamble:
4.\" ========================================================================
5.de Sp \" Vertical space (when we can't use .PP)
6.if t .sp .5v
7.if n .sp
8..
9.de Vb \" Begin verbatim text
10.ft CW
11.nf
12.ne \\$1
13..
14.de Ve \" End verbatim text
15.ft R
16.fi
17..
18.\" Set up some character translations and predefined strings. \*(-- will
19.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
20.\" double quote, and \*(R" will give a right double quote. \*(C+ will
21.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
22.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
23.\" nothing in troff, for use with C<>.
24.tr \(*W-
25.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
26.ie n \{\
27. ds -- \(*W-
28. ds PI pi
29. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
30. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
31. ds L" ""
32. ds R" ""
33. ds C` ""
34. ds C' ""
35'br\}
36.el\{\
37. ds -- \|\(em\|
38. ds PI \(*p
39. ds L" ``
40. ds R" ''
41'br\}
42.\"
43.\" Escape single quotes in literal strings from groff's Unicode transform.
44.ie \n(.g .ds Aq \(aq
45.el .ds Aq '
46.\"
47.\" If the F register is turned on, we'll generate index entries on stderr for
48.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
49.\" entries marked with X<> in POD. Of course, you'll have to process the
50.\" output yourself in some meaningful fashion.
51.ie \nF \{\
52. de IX
53. tm Index:\\$1\t\\n%\t"\\$2"
54..
55. nr % 0
56. rr F
57.\}
58.el \{\
59. de IX
60..
61.\}
62.\"
63.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
64.\" Fear. Run. Save yourself. No user-serviceable parts.
65. \" fudge factors for nroff and troff
66.if n \{\
67. ds #H 0
68. ds #V .8m
69. ds #F .3m
70. ds #[ \f1
71. ds #] \fP
72.\}
73.if t \{\
74. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
75. ds #V .6m
76. ds #F 0
77. ds #[ \&
78. ds #] \&
79.\}
80. \" simple accents for nroff and troff
81.if n \{\
82. ds ' \&
83. ds ` \&
84. ds ^ \&
85. ds , \&
86. ds ~ ~
87. ds /
88.\}
89.if t \{\
90. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
91. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
92. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
93. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
94. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
95. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
96.\}
97. \" troff and (daisy-wheel) nroff accents
98.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
99.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
100.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
101.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
102.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
103.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
104.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
105.ds ae a\h'-(\w'a'u*4/10)'e
106.ds Ae A\h'-(\w'A'u*4/10)'E
107. \" corrections for vroff
108.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
109.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
110. \" for low resolution devices (crt and lpr)
111.if \n(.H>23 .if \n(.V>19 \
112\{\
113. ds : e
114. ds 8 ss
115. ds o a
116. ds d- d\h'-1'\(ga
117. ds D- D\h'-1'\(hy
118. ds th \o'bp'
119. ds Th \o'LP'
120. ds ae ae
121. ds Ae AE
122.\}
123.rm #[ #] #H #V #F C
124.\" ========================================================================
125.\"
126.IX Title "BIO_f_ssl 3"
127.TH BIO_f_ssl 3 "2010-06-01" "1.0.0a" "OpenSSL"
128.\" For nroff, turn off justification. Always turn off hyphenation; it makes
129.\" way too many mistakes in technical documents.
130.if n .ad l
131.nh
132.SH "NAME"
133BIO_f_ssl, BIO_set_ssl, BIO_get_ssl, BIO_set_ssl_mode, BIO_set_ssl_renegotiate_bytes,
134BIO_get_num_renegotiates, BIO_set_ssl_renegotiate_timeout, BIO_new_ssl,
135BIO_new_ssl_connect, BIO_new_buffer_ssl_connect, BIO_ssl_copy_session_id,
136BIO_ssl_shutdown \- SSL BIO
137.SH "SYNOPSIS"
138.IX Header "SYNOPSIS"
139.Vb 2
140\& #include <openssl/bio.h>
141\& #include <openssl/ssl.h>
142\&
143\& BIO_METHOD *BIO_f_ssl(void);
144\&
145\& #define BIO_set_ssl(b,ssl,c) BIO_ctrl(b,BIO_C_SET_SSL,c,(char *)ssl)
146\& #define BIO_get_ssl(b,sslp) BIO_ctrl(b,BIO_C_GET_SSL,0,(char *)sslp)
147\& #define BIO_set_ssl_mode(b,client) BIO_ctrl(b,BIO_C_SSL_MODE,client,NULL)
148\& #define BIO_set_ssl_renegotiate_bytes(b,num) \e
149\& BIO_ctrl(b,BIO_C_SET_SSL_RENEGOTIATE_BYTES,num,NULL);
150\& #define BIO_set_ssl_renegotiate_timeout(b,seconds) \e
151\& BIO_ctrl(b,BIO_C_SET_SSL_RENEGOTIATE_TIMEOUT,seconds,NULL);
152\& #define BIO_get_num_renegotiates(b) \e
153\& BIO_ctrl(b,BIO_C_SET_SSL_NUM_RENEGOTIATES,0,NULL);
154\&
155\& BIO *BIO_new_ssl(SSL_CTX *ctx,int client);
156\& BIO *BIO_new_ssl_connect(SSL_CTX *ctx);
157\& BIO *BIO_new_buffer_ssl_connect(SSL_CTX *ctx);
158\& int BIO_ssl_copy_session_id(BIO *to,BIO *from);
159\& void BIO_ssl_shutdown(BIO *bio);
160\&
161\& #define BIO_do_handshake(b) BIO_ctrl(b,BIO_C_DO_STATE_MACHINE,0,NULL)
162.Ve
163.SH "DESCRIPTION"
164.IX Header "DESCRIPTION"
165\&\fIBIO_f_ssl()\fR returns the \s-1SSL\s0 \s-1BIO\s0 method. This is a filter \s-1BIO\s0 which
166is a wrapper round the OpenSSL \s-1SSL\s0 routines adding a \s-1BIO\s0 \*(L"flavour\*(R" to
167\&\s-1SSL\s0 I/O.
168.PP
169I/O performed on an \s-1SSL\s0 \s-1BIO\s0 communicates using the \s-1SSL\s0 protocol with
170the SSLs read and write BIOs. If an \s-1SSL\s0 connection is not established
171then an attempt is made to establish one on the first I/O call.
172.PP
173If a \s-1BIO\s0 is appended to an \s-1SSL\s0 \s-1BIO\s0 using \fIBIO_push()\fR it is automatically
174used as the \s-1SSL\s0 BIOs read and write BIOs.
175.PP
176Calling \fIBIO_reset()\fR on an \s-1SSL\s0 \s-1BIO\s0 closes down any current \s-1SSL\s0 connection
177by calling \fISSL_shutdown()\fR. \fIBIO_reset()\fR is then sent to the next \s-1BIO\s0 in
178the chain: this will typically disconnect the underlying transport.
179The \s-1SSL\s0 \s-1BIO\s0 is then reset to the initial accept or connect state.
180.PP
181If the close flag is set when an \s-1SSL\s0 \s-1BIO\s0 is freed then the internal
182\&\s-1SSL\s0 structure is also freed using \fISSL_free()\fR.
183.PP
184\&\fIBIO_set_ssl()\fR sets the internal \s-1SSL\s0 pointer of \s-1BIO\s0 \fBb\fR to \fBssl\fR using
185the close flag \fBc\fR.
186.PP
187\&\fIBIO_get_ssl()\fR retrieves the \s-1SSL\s0 pointer of \s-1BIO\s0 \fBb\fR, it can then be
188manipulated using the standard \s-1SSL\s0 library functions.
189.PP
190\&\fIBIO_set_ssl_mode()\fR sets the \s-1SSL\s0 \s-1BIO\s0 mode to \fBclient\fR. If \fBclient\fR
191is 1 client mode is set. If \fBclient\fR is 0 server mode is set.
192.PP
193\&\fIBIO_set_ssl_renegotiate_bytes()\fR sets the renegotiate byte count
194to \fBnum\fR. When set after every \fBnum\fR bytes of I/O (read and write)
195the \s-1SSL\s0 session is automatically renegotiated. \fBnum\fR must be at
196least 512 bytes.
197.PP
198\&\fIBIO_set_ssl_renegotiate_timeout()\fR sets the renegotiate timeout to
199\&\fBseconds\fR. When the renegotiate timeout elapses the session is
200automatically renegotiated.
201.PP
202\&\fIBIO_get_num_renegotiates()\fR returns the total number of session
203renegotiations due to I/O or timeout.
204.PP
205\&\fIBIO_new_ssl()\fR allocates an \s-1SSL\s0 \s-1BIO\s0 using \s-1SSL_CTX\s0 \fBctx\fR and using
206client mode if \fBclient\fR is non zero.
207.PP
208\&\fIBIO_new_ssl_connect()\fR creates a new \s-1BIO\s0 chain consisting of an
209\&\s-1SSL\s0 \s-1BIO\s0 (using \fBctx\fR) followed by a connect \s-1BIO\s0.
210.PP
211\&\fIBIO_new_buffer_ssl_connect()\fR creates a new \s-1BIO\s0 chain consisting
212of a buffering \s-1BIO\s0, an \s-1SSL\s0 \s-1BIO\s0 (using \fBctx\fR) and a connect
213\&\s-1BIO\s0.
214.PP
215\&\fIBIO_ssl_copy_session_id()\fR copies an \s-1SSL\s0 session id between
216\&\s-1BIO\s0 chains \fBfrom\fR and \fBto\fR. It does this by locating the
217\&\s-1SSL\s0 BIOs in each chain and calling \fISSL_copy_session_id()\fR on
218the internal \s-1SSL\s0 pointer.
219.PP
220\&\fIBIO_ssl_shutdown()\fR closes down an \s-1SSL\s0 connection on \s-1BIO\s0
221chain \fBbio\fR. It does this by locating the \s-1SSL\s0 \s-1BIO\s0 in the
222chain and calling \fISSL_shutdown()\fR on its internal \s-1SSL\s0
223pointer.
224.PP
225\&\fIBIO_do_handshake()\fR attempts to complete an \s-1SSL\s0 handshake on the
226supplied \s-1BIO\s0 and establish the \s-1SSL\s0 connection. It returns 1
227if the connection was established successfully. A zero or negative
228value is returned if the connection could not be established, the
229call \fIBIO_should_retry()\fR should be used for non blocking connect BIOs
230to determine if the call should be retried. If an \s-1SSL\s0 connection has
231already been established this call has no effect.
232.SH "NOTES"
233.IX Header "NOTES"
234\&\s-1SSL\s0 BIOs are exceptional in that if the underlying transport
235is non blocking they can still request a retry in exceptional
236circumstances. Specifically this will happen if a session
237renegotiation takes place during a \fIBIO_read()\fR operation, one
238case where this happens is when \s-1SGC\s0 or step up occurs.
239.PP
240In OpenSSL 0.9.6 and later the \s-1SSL\s0 flag \s-1SSL_AUTO_RETRY\s0 can be
241set to disable this behaviour. That is when this flag is set
242an \s-1SSL\s0 \s-1BIO\s0 using a blocking transport will never request a
243retry.
244.PP
245Since unknown \fIBIO_ctrl()\fR operations are sent through filter
246BIOs the servers name and port can be set using \fIBIO_set_host()\fR
247on the \s-1BIO\s0 returned by \fIBIO_new_ssl_connect()\fR without having
248to locate the connect \s-1BIO\s0 first.
249.PP
250Applications do not have to call \fIBIO_do_handshake()\fR but may wish
251to do so to separate the handshake process from other I/O
252processing.
253.SH "RETURN VALUES"
254.IX Header "RETURN VALUES"
255\&\s-1TBA\s0
256.SH "EXAMPLE"
257.IX Header "EXAMPLE"
258This \s-1SSL/TLS\s0 client example, attempts to retrieve a page from an
259\&\s-1SSL/TLS\s0 web server. The I/O routines are identical to those of the
260unencrypted example in \fIBIO_s_connect\fR\|(3).
261.PP
262.Vb 5
263\& BIO *sbio, *out;
264\& int len;
265\& char tmpbuf[1024];
266\& SSL_CTX *ctx;
267\& SSL *ssl;
268\&
269\& ERR_load_crypto_strings();
270\& ERR_load_SSL_strings();
271\& OpenSSL_add_all_algorithms();
272\&
273\& /* We would seed the PRNG here if the platform didn\*(Aqt
274\& * do it automatically
275\& */
276\&
277\& ctx = SSL_CTX_new(SSLv23_client_method());
278\&
279\& /* We\*(Aqd normally set some stuff like the verify paths and
280\& * mode here because as things stand this will connect to
281\& * any server whose certificate is signed by any CA.
282\& */
283\&
284\& sbio = BIO_new_ssl_connect(ctx);
285\&
286\& BIO_get_ssl(sbio, &ssl);
287\&
288\& if(!ssl) {
289\& fprintf(stderr, "Can\*(Aqt locate SSL pointer\en");
290\& /* whatever ... */
291\& }
292\&
293\& /* Don\*(Aqt want any retries */
294\& SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY);
295\&
296\& /* We might want to do other things with ssl here */
297\&
298\& BIO_set_conn_hostname(sbio, "localhost:https");
299\&
300\& out = BIO_new_fp(stdout, BIO_NOCLOSE);
301\& if(BIO_do_connect(sbio) <= 0) {
302\& fprintf(stderr, "Error connecting to server\en");
303\& ERR_print_errors_fp(stderr);
304\& /* whatever ... */
305\& }
306\&
307\& if(BIO_do_handshake(sbio) <= 0) {
308\& fprintf(stderr, "Error establishing SSL connection\en");
309\& ERR_print_errors_fp(stderr);
310\& /* whatever ... */
311\& }
312\&
313\& /* Could examine ssl here to get connection info */
314\&
315\& BIO_puts(sbio, "GET / HTTP/1.0\en\en");
316\& for(;;) {
317\& len = BIO_read(sbio, tmpbuf, 1024);
318\& if(len <= 0) break;
319\& BIO_write(out, tmpbuf, len);
320\& }
321\& BIO_free_all(sbio);
322\& BIO_free(out);
323.Ve
324.PP
325Here is a simple server example. It makes use of a buffering
326\&\s-1BIO\s0 to allow lines to be read from the \s-1SSL\s0 \s-1BIO\s0 using BIO_gets.
327It creates a pseudo web page containing the actual request from
328a client and also echoes the request to standard output.
329.PP
330.Vb 5
331\& BIO *sbio, *bbio, *acpt, *out;
332\& int len;
333\& char tmpbuf[1024];
334\& SSL_CTX *ctx;
335\& SSL *ssl;
336\&
337\& ERR_load_crypto_strings();
338\& ERR_load_SSL_strings();
339\& OpenSSL_add_all_algorithms();
340\&
341\& /* Might seed PRNG here */
342\&
343\& ctx = SSL_CTX_new(SSLv23_server_method());
344\&
345\& if (!SSL_CTX_use_certificate_file(ctx,"server.pem",SSL_FILETYPE_PEM)
346\& || !SSL_CTX_use_PrivateKey_file(ctx,"server.pem",SSL_FILETYPE_PEM)
347\& || !SSL_CTX_check_private_key(ctx)) {
348\&
349\& fprintf(stderr, "Error setting up SSL_CTX\en");
350\& ERR_print_errors_fp(stderr);
351\& return 0;
352\& }
353\&
354\& /* Might do other things here like setting verify locations and
355\& * DH and/or RSA temporary key callbacks
356\& */
357\&
358\& /* New SSL BIO setup as server */
359\& sbio=BIO_new_ssl(ctx,0);
360\&
361\& BIO_get_ssl(sbio, &ssl);
362\&
363\& if(!ssl) {
364\& fprintf(stderr, "Can\*(Aqt locate SSL pointer\en");
365\& /* whatever ... */
366\& }
367\&
368\& /* Don\*(Aqt want any retries */
369\& SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY);
370\&
371\& /* Create the buffering BIO */
372\&
373\& bbio = BIO_new(BIO_f_buffer());
374\&
375\& /* Add to chain */
376\& sbio = BIO_push(bbio, sbio);
377\&
378\& acpt=BIO_new_accept("4433");
379\&
380\& /* By doing this when a new connection is established
381\& * we automatically have sbio inserted into it. The
382\& * BIO chain is now \*(Aqswallowed\*(Aq by the accept BIO and
383\& * will be freed when the accept BIO is freed.
384\& */
385\&
386\& BIO_set_accept_bios(acpt,sbio);
387\&
388\& out = BIO_new_fp(stdout, BIO_NOCLOSE);
389\&
390\& /* Setup accept BIO */
391\& if(BIO_do_accept(acpt) <= 0) {
392\& fprintf(stderr, "Error setting up accept BIO\en");
393\& ERR_print_errors_fp(stderr);
394\& return 0;
395\& }
396\&
397\& /* Now wait for incoming connection */
398\& if(BIO_do_accept(acpt) <= 0) {
399\& fprintf(stderr, "Error in connection\en");
400\& ERR_print_errors_fp(stderr);
401\& return 0;
402\& }
403\&
404\& /* We only want one connection so remove and free
405\& * accept BIO
406\& */
407\&
408\& sbio = BIO_pop(acpt);
409\&
410\& BIO_free_all(acpt);
411\&
412\& if(BIO_do_handshake(sbio) <= 0) {
413\& fprintf(stderr, "Error in SSL handshake\en");
414\& ERR_print_errors_fp(stderr);
415\& return 0;
416\& }
417\&
418\& BIO_puts(sbio, "HTTP/1.0 200 OK\er\enContent\-type: text/plain\er\en\er\en");
419\& BIO_puts(sbio, "\er\enConnection Established\er\enRequest headers:\er\en");
420\& BIO_puts(sbio, "\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\er\en");
421\&
422\& for(;;) {
423\& len = BIO_gets(sbio, tmpbuf, 1024);
424\& if(len <= 0) break;
425\& BIO_write(sbio, tmpbuf, len);
426\& BIO_write(out, tmpbuf, len);
427\& /* Look for blank line signifying end of headers*/
428\& if((tmpbuf[0] == \*(Aq\er\*(Aq) || (tmpbuf[0] == \*(Aq\en\*(Aq)) break;
429\& }
430\&
431\& BIO_puts(sbio, "\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\er\en");
432\& BIO_puts(sbio, "\er\en");
433\&
434\& /* Since there is a buffering BIO present we had better flush it */
435\& BIO_flush(sbio);
436\&
437\& BIO_free_all(sbio);
438.Ve
439.SH "BUGS"
440.IX Header "BUGS"
441In OpenSSL versions before 1.0.0 the \fIBIO_pop()\fR call was handled incorrectly,
442the I/O \s-1BIO\s0 reference count was incorrectly incremented (instead of
443decremented) and dissociated with the \s-1SSL\s0 \s-1BIO\s0 even if the \s-1SSL\s0 \s-1BIO\s0 was not
444explicitly being popped (e.g. a pop higher up the chain). Applications which
445included workarounds for this bug (e.g. freeing BIOs more than once) should
446be modified to handle this fix or they may free up an already freed \s-1BIO\s0.
447.SH "SEE ALSO"
448.IX Header "SEE ALSO"
449\&\s-1TBA\s0