2 * Copyright (c) 2008, 2009, 2010 Nicira Networks.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include "stream-ssl.h"
25 #include <netinet/tcp.h>
26 #include <openssl/err.h>
27 #include <openssl/ssl.h>
28 #include <openssl/x509v3.h>
30 #include <sys/fcntl.h>
34 #include "dynamic-string.h"
35 #include "leak-checker.h"
37 #include "openflow/openflow.h"
39 #include "poll-loop.h"
41 #include "socket-util.h"
43 #include "stream-provider.h"
48 VLOG_DEFINE_THIS_MODULE(stream_ssl
);
50 COVERAGE_DEFINE(ssl_session
);
51 COVERAGE_DEFINE(ssl_session_reused
);
69 enum session_type type
;
73 unsigned int session_nr
;
75 /* rx_want and tx_want record the result of the last call to SSL_read()
76 * and SSL_write(), respectively:
78 * - If the call reported that data needed to be read from the file
79 * descriptor, the corresponding member is set to SSL_READING.
81 * - If the call reported that data needed to be written to the file
82 * descriptor, the corresponding member is set to SSL_WRITING.
84 * - Otherwise, the member is set to SSL_NOTHING, indicating that the
85 * call completed successfully (or with an error) and that there is no
88 * These are needed because there is no way to ask OpenSSL what a data read
89 * or write would require without giving it a buffer to receive into or
90 * data to send, respectively. (Note that the SSL_want() status is
91 * overwritten by each SSL_read() or SSL_write() call, so we can't rely on
94 * A single call to SSL_read() or SSL_write() can perform both reading
95 * and writing and thus invalidate not one of these values but actually
96 * both. Consider this situation, for example:
98 * - SSL_write() blocks on a read, so tx_want gets SSL_READING.
100 * - SSL_read() laters succeeds reading from 'fd' and clears out the
101 * whole receive buffer, so rx_want gets SSL_READING.
103 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
106 * - Now we're stuck blocking until the peer sends us data, even though
107 * SSL_write() could now succeed, which could easily be a deadlock
110 * On the other hand, we can't reset both tx_want and rx_want on every call
111 * to SSL_read() or SSL_write(), because that would produce livelock,
112 * e.g. in this situation:
114 * - SSL_write() blocks, so tx_want gets SSL_READING or SSL_WRITING.
116 * - SSL_read() blocks, so rx_want gets SSL_READING or SSL_WRITING,
117 * but tx_want gets reset to SSL_NOTHING.
119 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
122 * - Client wakes up immediately since SSL_NOTHING in tx_want indicates
123 * that no blocking is necessary.
125 * The solution we adopt here is to set tx_want to SSL_NOTHING after
126 * calling SSL_read() only if the SSL state of the connection changed,
127 * which indicates that an SSL-level renegotiation made some progress, and
128 * similarly for rx_want and SSL_write(). This prevents both the
129 * deadlock and livelock situations above.
131 int rx_want
, tx_want
;
133 /* A few bytes of header data in case SSL negotiation fails. */
138 /* SSL context created by ssl_init(). */
141 /* Maps from stream target (e.g. "127.0.0.1:1234") to SSL_SESSION *. The
142 * sessions are those from the last SSL connection to the given target.
143 * OpenSSL caches server-side sessions internally, so this cache is only used
144 * for client connections.
146 * The stream_ssl module owns a reference to each of the sessions in this
147 * table, so they must be freed with SSL_SESSION_free() when they are no
149 static struct shash client_sessions
= SHASH_INITIALIZER(&client_sessions
);
151 /* Maximum number of client sessions to cache. Ordinarily I'd expect that one
152 * session would be sufficient but this should cover it. */
153 #define MAX_CLIENT_SESSION_CACHE 16
155 struct ssl_config_file
{
156 bool read
; /* Whether the file was successfully read. */
157 char *file_name
; /* Configured file name, if any. */
158 struct timespec mtime
; /* File mtime as of last time we read it. */
161 /* SSL configuration files. */
162 static struct ssl_config_file private_key
;
163 static struct ssl_config_file certificate
;
164 static struct ssl_config_file ca_cert
;
166 /* Ordinarily, the SSL client and server verify each other's certificates using
167 * a CA certificate. Setting this to false disables this behavior. (This is a
169 static bool verify_peer_cert
= true;
171 /* Ordinarily, we require a CA certificate for the peer to be locally
172 * available. We can, however, bootstrap the CA certificate from the peer at
173 * the beginning of our first connection then use that certificate on all
174 * subsequent connections, saving it to a file for use in future runs also. In
175 * this case, 'bootstrap_ca_cert' is true. */
176 static bool bootstrap_ca_cert
;
178 /* Session number. Used in debug logging messages to uniquely identify a
180 static unsigned int next_session_nr
;
182 /* Who knows what can trigger various SSL errors, so let's throttle them down
184 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(10, 25);
186 static int ssl_init(void);
187 static int do_ssl_init(void);
188 static bool ssl_wants_io(int ssl_error
);
189 static void ssl_close(struct stream
*);
190 static void ssl_clear_txbuf(struct ssl_stream
*);
191 static int interpret_ssl_error(const char *function
, int ret
, int error
,
193 static DH
*tmp_dh_callback(SSL
*ssl
, int is_export OVS_UNUSED
, int keylength
);
194 static void log_ca_cert(const char *file_name
, X509
*cert
);
195 static void stream_ssl_set_ca_cert_file__(const char *file_name
,
197 static void ssl_protocol_cb(int write_p
, int version
, int content_type
,
198 const void *, size_t, SSL
*, void *sslv_
);
201 want_to_poll_events(int want
)
219 new_ssl_stream(const char *name
, int fd
, enum session_type type
,
220 enum ssl_state state
, const struct sockaddr_in
*remote
,
221 struct stream
**streamp
)
223 struct sockaddr_in local
;
224 socklen_t local_len
= sizeof local
;
225 struct ssl_stream
*sslv
;
230 /* Check for all the needful configuration. */
232 if (!private_key
.read
) {
233 VLOG_ERR("Private key must be configured to use SSL");
234 retval
= ENOPROTOOPT
;
236 if (!certificate
.read
) {
237 VLOG_ERR("Certificate must be configured to use SSL");
238 retval
= ENOPROTOOPT
;
240 if (!ca_cert
.read
&& verify_peer_cert
&& !bootstrap_ca_cert
) {
241 VLOG_ERR("CA certificate must be configured to use SSL");
242 retval
= ENOPROTOOPT
;
244 if (!SSL_CTX_check_private_key(ctx
)) {
245 VLOG_ERR("Private key does not match certificate public key: %s",
246 ERR_error_string(ERR_get_error(), NULL
));
247 retval
= ENOPROTOOPT
;
253 /* Get the local IP and port information */
254 retval
= getsockname(fd
, (struct sockaddr
*) &local
, &local_len
);
256 memset(&local
, 0, sizeof local
);
260 retval
= setsockopt(fd
, IPPROTO_TCP
, TCP_NODELAY
, &on
, sizeof on
);
262 VLOG_ERR("%s: setsockopt(TCP_NODELAY): %s", name
, strerror(errno
));
267 /* Create and configure OpenSSL stream. */
270 VLOG_ERR("SSL_new: %s", ERR_error_string(ERR_get_error(), NULL
));
271 retval
= ENOPROTOOPT
;
274 if (SSL_set_fd(ssl
, fd
) == 0) {
275 VLOG_ERR("SSL_set_fd: %s", ERR_error_string(ERR_get_error(), NULL
));
276 retval
= ENOPROTOOPT
;
279 if (!verify_peer_cert
|| (bootstrap_ca_cert
&& type
== CLIENT
)) {
280 SSL_set_verify(ssl
, SSL_VERIFY_NONE
, NULL
);
283 /* Create and return the ssl_stream. */
284 sslv
= xmalloc(sizeof *sslv
);
285 stream_init(&sslv
->stream
, &ssl_stream_class
, EAGAIN
, name
);
286 stream_set_remote_ip(&sslv
->stream
, remote
->sin_addr
.s_addr
);
287 stream_set_remote_port(&sslv
->stream
, remote
->sin_port
);
288 stream_set_local_ip(&sslv
->stream
, local
.sin_addr
.s_addr
);
289 stream_set_local_port(&sslv
->stream
, local
.sin_port
);
295 sslv
->rx_want
= sslv
->tx_want
= SSL_NOTHING
;
296 sslv
->session_nr
= next_session_nr
++;
299 if (VLOG_IS_DBG_ENABLED()) {
300 SSL_set_msg_callback(ssl
, ssl_protocol_cb
);
301 SSL_set_msg_callback_arg(ssl
, sslv
);
304 *streamp
= &sslv
->stream
;
315 static struct ssl_stream
*
316 ssl_stream_cast(struct stream
*stream
)
318 stream_assert_class(stream
, &ssl_stream_class
);
319 return CONTAINER_OF(stream
, struct ssl_stream
, stream
);
323 ssl_open(const char *name
, char *suffix
, struct stream
**streamp
)
325 struct sockaddr_in sin
;
333 error
= inet_open_active(SOCK_STREAM
, suffix
, OFP_SSL_PORT
, &sin
, &fd
);
335 int state
= error
? STATE_TCP_CONNECTING
: STATE_SSL_CONNECTING
;
336 return new_ssl_stream(name
, fd
, CLIENT
, state
, &sin
, streamp
);
338 VLOG_ERR("%s: connect: %s", name
, strerror(error
));
344 do_ca_cert_bootstrap(struct stream
*stream
)
346 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
347 STACK_OF(X509
) *chain
;
353 chain
= SSL_get_peer_cert_chain(sslv
->ssl
);
354 if (!chain
|| !sk_X509_num(chain
)) {
355 VLOG_ERR("could not bootstrap CA cert: no certificate presented by "
359 cert
= sk_X509_value(chain
, sk_X509_num(chain
) - 1);
361 /* Check that 'cert' is self-signed. Otherwise it is not a CA
362 * certificate and we should not attempt to use it as one. */
363 error
= X509_check_issued(cert
, cert
);
365 VLOG_ERR("could not bootstrap CA cert: obtained certificate is "
366 "not self-signed (%s)",
367 X509_verify_cert_error_string(error
));
368 if (sk_X509_num(chain
) < 2) {
369 VLOG_ERR("only one certificate was received, so probably the peer "
370 "is not configured to send its CA certificate");
375 fd
= open(ca_cert
.file_name
, O_CREAT
| O_EXCL
| O_WRONLY
, 0444);
377 if (errno
== EEXIST
) {
378 VLOG_INFO("reading CA cert %s created by another process",
380 stream_ssl_set_ca_cert_file(ca_cert
.file_name
, true);
383 VLOG_ERR("could not bootstrap CA cert: creating %s failed: %s",
384 ca_cert
.file_name
, strerror(errno
));
389 file
= fdopen(fd
, "w");
392 VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s",
394 unlink(ca_cert
.file_name
);
398 if (!PEM_write_X509(file
, cert
)) {
399 VLOG_ERR("could not bootstrap CA cert: PEM_write_X509 to %s failed: "
400 "%s", ca_cert
.file_name
,
401 ERR_error_string(ERR_get_error(), NULL
));
403 unlink(ca_cert
.file_name
);
409 VLOG_ERR("could not bootstrap CA cert: writing %s failed: %s",
410 ca_cert
.file_name
, strerror(error
));
411 unlink(ca_cert
.file_name
);
415 VLOG_INFO("successfully bootstrapped CA cert to %s", ca_cert
.file_name
);
416 log_ca_cert(ca_cert
.file_name
, cert
);
417 bootstrap_ca_cert
= false;
420 /* SSL_CTX_add_client_CA makes a copy of cert's relevant data. */
421 SSL_CTX_add_client_CA(ctx
, cert
);
423 /* SSL_CTX_use_certificate() takes ownership of the certificate passed in.
424 * 'cert' is owned by sslv->ssl, so we need to duplicate it. */
425 cert
= X509_dup(cert
);
429 if (SSL_CTX_load_verify_locations(ctx
, ca_cert
.file_name
, NULL
) != 1) {
430 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
431 ERR_error_string(ERR_get_error(), NULL
));
434 VLOG_INFO("killing successful connection to retry using CA cert");
439 ssl_delete_session(struct shash_node
*node
)
441 SSL_SESSION
*session
= node
->data
;
442 SSL_SESSION_free(session
);
443 shash_delete(&client_sessions
, node
);
446 /* Find and free any previously cached session for 'stream''s target. */
448 ssl_flush_session(struct stream
*stream
)
450 struct shash_node
*node
;
452 node
= shash_find(&client_sessions
, stream_get_name(stream
));
454 ssl_delete_session(node
);
458 /* Add 'stream''s session to the cache for its target, so that it will be
459 * reused for future SSL connections to the same target. */
461 ssl_cache_session(struct stream
*stream
)
463 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
464 SSL_SESSION
*session
;
467 COVERAGE_INC(ssl_session
);
468 if (SSL_session_reused(sslv
->ssl
)) {
469 COVERAGE_INC(ssl_session_reused
);
472 /* Get session from stream. */
473 session
= SSL_get1_session(sslv
->ssl
);
475 SSL_SESSION
*old_session
;
477 old_session
= shash_replace(&client_sessions
, stream_get_name(stream
),
480 /* Free the session that we replaced. (We might actually have
481 * session == old_session, but either way we have to free it to
482 * avoid leaking a reference.) */
483 SSL_SESSION_free(old_session
);
484 } else if (shash_count(&client_sessions
) > MAX_CLIENT_SESSION_CACHE
) {
486 struct shash_node
*node
= shash_random_node(&client_sessions
);
487 if (node
->data
!= session
) {
488 ssl_delete_session(node
);
494 /* There is no new session. This doesn't really make sense because
495 * this function is only called upon successful connection and there
496 * should always be a new session in that case. But I don't trust
497 * OpenSSL so I'd rather handle this case anyway. */
498 ssl_flush_session(stream
);
503 ssl_connect(struct stream
*stream
)
505 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
508 switch (sslv
->state
) {
509 case STATE_TCP_CONNECTING
:
510 retval
= check_connection_completion(sslv
->fd
);
514 sslv
->state
= STATE_SSL_CONNECTING
;
517 case STATE_SSL_CONNECTING
:
518 /* Capture the first few bytes of received data so that we can guess
519 * what kind of funny data we've been sent if SSL negotation fails. */
520 if (sslv
->n_head
<= 0) {
521 sslv
->n_head
= recv(sslv
->fd
, sslv
->head
, sizeof sslv
->head
,
525 /* Grab SSL session information from the cache. */
526 if (sslv
->type
== CLIENT
) {
527 SSL_SESSION
*session
= shash_find_data(&client_sessions
,
528 stream_get_name(stream
));
530 SSL_set_session(sslv
->ssl
, session
);
534 retval
= (sslv
->type
== CLIENT
535 ? SSL_connect(sslv
->ssl
) : SSL_accept(sslv
->ssl
));
537 int error
= SSL_get_error(sslv
->ssl
, retval
);
538 if (retval
< 0 && ssl_wants_io(error
)) {
543 if (sslv
->type
== CLIENT
) {
544 /* Delete any cached session for this stream's target.
545 * Otherwise a single error causes recurring errors that
546 * don't resolve until the SSL client or server is
547 * restarted. (It can take dozens of reused connections to
548 * see this behavior, so this is difficult to test.) If we
549 * delete the session on the first error, though, the error
550 * only occurs once and then resolves itself. */
551 ssl_flush_session(stream
);
554 interpret_ssl_error((sslv
->type
== CLIENT
? "SSL_connect"
555 : "SSL_accept"), retval
, error
, &unused
);
556 shutdown(sslv
->fd
, SHUT_RDWR
);
557 stream_report_content(sslv
->head
, sslv
->n_head
, STREAM_SSL
,
558 THIS_MODULE
, stream_get_name(stream
));
561 } else if (bootstrap_ca_cert
) {
562 return do_ca_cert_bootstrap(stream
);
563 } else if (verify_peer_cert
564 && ((SSL_get_verify_mode(sslv
->ssl
)
565 & (SSL_VERIFY_NONE
| SSL_VERIFY_PEER
))
566 != SSL_VERIFY_PEER
)) {
567 /* Two or more SSL connections completed at the same time while we
568 * were in bootstrap mode. Only one of these can finish the
569 * bootstrap successfully. The other one(s) must be rejected
570 * because they were not verified against the bootstrapped CA
571 * certificate. (Alternatively we could verify them against the CA
572 * certificate, but that's more trouble than it's worth. These
573 * connections will succeed the next time they retry, assuming that
574 * they have a certificate against the correct CA.) */
575 VLOG_ERR("rejecting SSL connection during bootstrap race window");
578 if (sslv
->type
== CLIENT
) {
579 ssl_cache_session(stream
);
589 ssl_close(struct stream
*stream
)
591 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
592 ssl_clear_txbuf(sslv
);
594 /* Attempt clean shutdown of the SSL connection. This will work most of
595 * the time, as long as the kernel send buffer has some free space and the
596 * SSL connection isn't renegotiating, etc. That has to be good enough,
597 * since we don't have any way to continue the close operation in the
599 SSL_shutdown(sslv
->ssl
);
601 /* SSL_shutdown() might have signaled an error, in which case we need to
602 * flush it out of the OpenSSL error queue or the next OpenSSL operation
603 * will falsely signal an error. */
612 interpret_ssl_error(const char *function
, int ret
, int error
,
619 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_NONE", function
);
622 case SSL_ERROR_ZERO_RETURN
:
623 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_ZERO_RETURN", function
);
626 case SSL_ERROR_WANT_READ
:
630 case SSL_ERROR_WANT_WRITE
:
634 case SSL_ERROR_WANT_CONNECT
:
635 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_WANT_CONNECT", function
);
638 case SSL_ERROR_WANT_ACCEPT
:
639 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_WANT_ACCEPT", function
);
642 case SSL_ERROR_WANT_X509_LOOKUP
:
643 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_WANT_X509_LOOKUP",
647 case SSL_ERROR_SYSCALL
: {
648 int queued_error
= ERR_get_error();
649 if (queued_error
== 0) {
652 VLOG_WARN_RL(&rl
, "%s: system error (%s)",
653 function
, strerror(status
));
656 VLOG_WARN_RL(&rl
, "%s: unexpected SSL connection close",
661 VLOG_WARN_RL(&rl
, "%s: %s",
662 function
, ERR_error_string(queued_error
, NULL
));
667 case SSL_ERROR_SSL
: {
668 int queued_error
= ERR_get_error();
669 if (queued_error
!= 0) {
670 VLOG_WARN_RL(&rl
, "%s: %s",
671 function
, ERR_error_string(queued_error
, NULL
));
673 VLOG_ERR_RL(&rl
, "%s: SSL_ERROR_SSL without queued error",
680 VLOG_ERR_RL(&rl
, "%s: bad SSL error code %d", function
, error
);
687 ssl_recv(struct stream
*stream
, void *buffer
, size_t n
)
689 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
693 /* Behavior of zero-byte SSL_read is poorly defined. */
696 old_state
= SSL_get_state(sslv
->ssl
);
697 ret
= SSL_read(sslv
->ssl
, buffer
, n
);
698 if (old_state
!= SSL_get_state(sslv
->ssl
)) {
699 sslv
->tx_want
= SSL_NOTHING
;
701 sslv
->rx_want
= SSL_NOTHING
;
706 int error
= SSL_get_error(sslv
->ssl
, ret
);
707 if (error
== SSL_ERROR_ZERO_RETURN
) {
710 return -interpret_ssl_error("SSL_read", ret
, error
,
717 ssl_clear_txbuf(struct ssl_stream
*sslv
)
719 ofpbuf_delete(sslv
->txbuf
);
724 ssl_do_tx(struct stream
*stream
)
726 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
729 int old_state
= SSL_get_state(sslv
->ssl
);
730 int ret
= SSL_write(sslv
->ssl
, sslv
->txbuf
->data
, sslv
->txbuf
->size
);
731 if (old_state
!= SSL_get_state(sslv
->ssl
)) {
732 sslv
->rx_want
= SSL_NOTHING
;
734 sslv
->tx_want
= SSL_NOTHING
;
736 ofpbuf_pull(sslv
->txbuf
, ret
);
737 if (sslv
->txbuf
->size
== 0) {
741 int ssl_error
= SSL_get_error(sslv
->ssl
, ret
);
742 if (ssl_error
== SSL_ERROR_ZERO_RETURN
) {
743 VLOG_WARN_RL(&rl
, "SSL_write: connection closed");
746 return interpret_ssl_error("SSL_write", ret
, ssl_error
,
754 ssl_send(struct stream
*stream
, const void *buffer
, size_t n
)
756 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
763 sslv
->txbuf
= ofpbuf_clone_data(buffer
, n
);
764 error
= ssl_do_tx(stream
);
767 ssl_clear_txbuf(sslv
);
770 leak_checker_claim(buffer
);
780 ssl_run(struct stream
*stream
)
782 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
784 if (sslv
->txbuf
&& ssl_do_tx(stream
) != EAGAIN
) {
785 ssl_clear_txbuf(sslv
);
790 ssl_run_wait(struct stream
*stream
)
792 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
794 if (sslv
->tx_want
!= SSL_NOTHING
) {
795 poll_fd_wait(sslv
->fd
, want_to_poll_events(sslv
->tx_want
));
800 ssl_wait(struct stream
*stream
, enum stream_wait_type wait
)
802 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
806 if (stream_connect(stream
) != EAGAIN
) {
807 poll_immediate_wake();
809 switch (sslv
->state
) {
810 case STATE_TCP_CONNECTING
:
811 poll_fd_wait(sslv
->fd
, POLLOUT
);
814 case STATE_SSL_CONNECTING
:
815 /* ssl_connect() called SSL_accept() or SSL_connect(), which
816 * set up the status that we test here. */
817 poll_fd_wait(sslv
->fd
,
818 want_to_poll_events(SSL_want(sslv
->ssl
)));
828 if (sslv
->rx_want
!= SSL_NOTHING
) {
829 poll_fd_wait(sslv
->fd
, want_to_poll_events(sslv
->rx_want
));
831 poll_immediate_wake();
837 /* We have room in our tx queue. */
838 poll_immediate_wake();
840 /* stream_run_wait() will do the right thing; don't bother with
850 struct stream_class ssl_stream_class
= {
853 ssl_close
, /* close */
854 ssl_connect
, /* connect */
858 ssl_run_wait
, /* run_wait */
866 struct pstream pstream
;
870 struct pstream_class pssl_pstream_class
;
872 static struct pssl_pstream
*
873 pssl_pstream_cast(struct pstream
*pstream
)
875 pstream_assert_class(pstream
, &pssl_pstream_class
);
876 return CONTAINER_OF(pstream
, struct pssl_pstream
, pstream
);
880 pssl_open(const char *name OVS_UNUSED
, char *suffix
, struct pstream
**pstreamp
)
882 struct pssl_pstream
*pssl
;
883 struct sockaddr_in sin
;
884 char bound_name
[128];
893 fd
= inet_open_passive(SOCK_STREAM
, suffix
, OFP_SSL_PORT
, &sin
);
897 sprintf(bound_name
, "pssl:%"PRIu16
":"IP_FMT
,
898 ntohs(sin
.sin_port
), IP_ARGS(&sin
.sin_addr
.s_addr
));
900 pssl
= xmalloc(sizeof *pssl
);
901 pstream_init(&pssl
->pstream
, &pssl_pstream_class
, bound_name
);
903 *pstreamp
= &pssl
->pstream
;
908 pssl_close(struct pstream
*pstream
)
910 struct pssl_pstream
*pssl
= pssl_pstream_cast(pstream
);
916 pssl_accept(struct pstream
*pstream
, struct stream
**new_streamp
)
918 struct pssl_pstream
*pssl
= pssl_pstream_cast(pstream
);
919 struct sockaddr_in sin
;
920 socklen_t sin_len
= sizeof sin
;
925 new_fd
= accept(pssl
->fd
, &sin
, &sin_len
);
928 if (error
!= EAGAIN
) {
929 VLOG_DBG_RL(&rl
, "accept: %s", strerror(error
));
934 error
= set_nonblocking(new_fd
);
940 sprintf(name
, "ssl:"IP_FMT
, IP_ARGS(&sin
.sin_addr
));
941 if (sin
.sin_port
!= htons(OFP_SSL_PORT
)) {
942 sprintf(strchr(name
, '\0'), ":%"PRIu16
, ntohs(sin
.sin_port
));
944 return new_ssl_stream(name
, new_fd
, SERVER
, STATE_SSL_CONNECTING
, &sin
,
949 pssl_wait(struct pstream
*pstream
)
951 struct pssl_pstream
*pssl
= pssl_pstream_cast(pstream
);
952 poll_fd_wait(pssl
->fd
, POLLIN
);
955 struct pstream_class pssl_pstream_class
= {
964 * Returns true if OpenSSL error is WANT_READ or WANT_WRITE, indicating that
965 * OpenSSL is requesting that we call it back when the socket is ready for read
966 * or writing, respectively.
969 ssl_wants_io(int ssl_error
)
971 return (ssl_error
== SSL_ERROR_WANT_WRITE
972 || ssl_error
== SSL_ERROR_WANT_READ
);
978 static int init_status
= -1;
979 if (init_status
< 0) {
980 init_status
= do_ssl_init();
981 assert(init_status
>= 0);
992 SSL_load_error_strings();
994 /* New OpenSSL changed TLSv1_method() to return a "const" pointer, so the
995 * cast is needed to avoid a warning with those newer versions. */
996 method
= (SSL_METHOD
*) TLSv1_method();
997 if (method
== NULL
) {
998 VLOG_ERR("TLSv1_method: %s", ERR_error_string(ERR_get_error(), NULL
));
1002 ctx
= SSL_CTX_new(method
);
1004 VLOG_ERR("SSL_CTX_new: %s", ERR_error_string(ERR_get_error(), NULL
));
1007 SSL_CTX_set_options(ctx
, SSL_OP_NO_SSLv2
| SSL_OP_NO_SSLv3
);
1008 SSL_CTX_set_tmp_dh_callback(ctx
, tmp_dh_callback
);
1009 SSL_CTX_set_mode(ctx
, SSL_MODE_ENABLE_PARTIAL_WRITE
);
1010 SSL_CTX_set_mode(ctx
, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER
);
1011 SSL_CTX_set_verify(ctx
, SSL_VERIFY_PEER
| SSL_VERIFY_FAIL_IF_NO_PEER_CERT
,
1014 /* We have to set a session context ID string in 'ctx' because OpenSSL
1015 * otherwise refuses to use a cached session on the server side when
1016 * SSL_VERIFY_PEER is set. And it not only refuses to use the cached
1017 * session, it actually generates an error and kills the connection.
1018 * According to a comment in ssl_get_prev_session() in OpenSSL's
1019 * ssl/ssl_sess.c, this is intentional behavior.
1021 * Any context string is OK, as long as one is set. */
1022 SSL_CTX_set_session_id_context(ctx
, (const unsigned char *) PACKAGE
,
1029 tmp_dh_callback(SSL
*ssl OVS_UNUSED
, int is_export OVS_UNUSED
, int keylength
)
1034 DH
*(*constructor
)(void);
1037 static struct dh dh_table
[] = {
1038 {1024, NULL
, get_dh1024
},
1039 {2048, NULL
, get_dh2048
},
1040 {4096, NULL
, get_dh4096
},
1045 for (dh
= dh_table
; dh
< &dh_table
[ARRAY_SIZE(dh_table
)]; dh
++) {
1046 if (dh
->keylength
== keylength
) {
1048 dh
->dh
= dh
->constructor();
1050 ovs_fatal(ENOMEM
, "out of memory constructing "
1051 "Diffie-Hellman parameters");
1057 VLOG_ERR_RL(&rl
, "no Diffie-Hellman parameters for key length %d",
1062 /* Returns true if SSL is at least partially configured. */
1064 stream_ssl_is_configured(void)
1066 return private_key
.file_name
|| certificate
.file_name
|| ca_cert
.file_name
;
1070 update_ssl_config(struct ssl_config_file
*config
, const char *file_name
)
1072 struct timespec mtime
;
1074 if (ssl_init() || !file_name
) {
1078 /* If the file name hasn't changed and neither has the file contents, stop
1080 get_mtime(file_name
, &mtime
);
1081 if (config
->file_name
1082 && !strcmp(config
->file_name
, file_name
)
1083 && mtime
.tv_sec
== config
->mtime
.tv_sec
1084 && mtime
.tv_nsec
== config
->mtime
.tv_nsec
) {
1088 /* Update 'config'. */
1089 config
->mtime
= mtime
;
1090 if (file_name
!= config
->file_name
) {
1091 free(config
->file_name
);
1092 config
->file_name
= xstrdup(file_name
);
1098 stream_ssl_set_private_key_file__(const char *file_name
)
1100 if (SSL_CTX_use_PrivateKey_file(ctx
, file_name
, SSL_FILETYPE_PEM
) == 1) {
1101 private_key
.read
= true;
1103 VLOG_ERR("SSL_use_PrivateKey_file: %s",
1104 ERR_error_string(ERR_get_error(), NULL
));
1109 stream_ssl_set_private_key_file(const char *file_name
)
1111 if (update_ssl_config(&private_key
, file_name
)) {
1112 stream_ssl_set_private_key_file__(file_name
);
1117 stream_ssl_set_certificate_file__(const char *file_name
)
1119 if (SSL_CTX_use_certificate_chain_file(ctx
, file_name
) == 1) {
1120 certificate
.read
= true;
1122 VLOG_ERR("SSL_use_certificate_file: %s",
1123 ERR_error_string(ERR_get_error(), NULL
));
1128 stream_ssl_set_certificate_file(const char *file_name
)
1130 if (update_ssl_config(&certificate
, file_name
)) {
1131 stream_ssl_set_certificate_file__(file_name
);
1135 /* Sets the private key and certificate files in one operation. Use this
1136 * interface, instead of calling stream_ssl_set_private_key_file() and
1137 * stream_ssl_set_certificate_file() individually, in the main loop of a
1138 * long-running program whose key and certificate might change at runtime.
1140 * This is important because of OpenSSL's behavior. If an OpenSSL context
1141 * already has a certificate, and stream_ssl_set_private_key_file() is called
1142 * to install a new private key, OpenSSL will report an error because the new
1143 * private key does not match the old certificate. The other order, of setting
1144 * a new certificate, then setting a new private key, does work.
1146 * If this were the only problem, calling stream_ssl_set_certificate_file()
1147 * before stream_ssl_set_private_key_file() would fix it. But, if the private
1148 * key is changed before the certificate (e.g. someone "scp"s or "mv"s the new
1149 * private key in place before the certificate), then OpenSSL would reject that
1150 * change, and then the change of certificate would succeed, but there would be
1151 * no associated private key (because it had only changed once and therefore
1152 * there was no point in re-reading it).
1154 * This function avoids both problems by, whenever either the certificate or
1155 * the private key file changes, re-reading both of them, in the correct order.
1158 stream_ssl_set_key_and_cert(const char *private_key_file
,
1159 const char *certificate_file
)
1161 if (update_ssl_config(&private_key
, private_key_file
)
1162 || update_ssl_config(&certificate
, certificate_file
)) {
1163 stream_ssl_set_certificate_file__(certificate_file
);
1164 stream_ssl_set_private_key_file__(private_key_file
);
1168 /* Reads the X509 certificate or certificates in file 'file_name'. On success,
1169 * stores the address of the first element in an array of pointers to
1170 * certificates in '*certs' and the number of certificates in the array in
1171 * '*n_certs', and returns 0. On failure, stores a null pointer in '*certs', 0
1172 * in '*n_certs', and returns a positive errno value.
1174 * The caller is responsible for freeing '*certs'. */
1176 read_cert_file(const char *file_name
, X509
***certs
, size_t *n_certs
)
1179 size_t allocated_certs
= 0;
1184 file
= fopen(file_name
, "r");
1186 VLOG_ERR("failed to open %s for reading: %s",
1187 file_name
, strerror(errno
));
1195 /* Read certificate from file. */
1196 certificate
= PEM_read_X509(file
, NULL
, NULL
, NULL
);
1200 VLOG_ERR("PEM_read_X509 failed reading %s: %s",
1201 file_name
, ERR_error_string(ERR_get_error(), NULL
));
1202 for (i
= 0; i
< *n_certs
; i
++) {
1203 X509_free((*certs
)[i
]);
1211 /* Add certificate to array. */
1212 if (*n_certs
>= allocated_certs
) {
1213 *certs
= x2nrealloc(*certs
, &allocated_certs
, sizeof **certs
);
1215 (*certs
)[(*n_certs
)++] = certificate
;
1217 /* Are there additional certificates in the file? */
1220 } while (isspace(c
));
1231 /* Sets 'file_name' as the name of a file containing one or more X509
1232 * certificates to send to the peer. Typical use in OpenFlow is to send the CA
1233 * certificate to the peer, which enables a switch to pick up the controller's
1234 * CA certificate on its first connection. */
1236 stream_ssl_set_peer_ca_cert_file(const char *file_name
)
1246 if (!read_cert_file(file_name
, &certs
, &n_certs
)) {
1247 for (i
= 0; i
< n_certs
; i
++) {
1248 if (SSL_CTX_add_extra_chain_cert(ctx
, certs
[i
]) != 1) {
1249 VLOG_ERR("SSL_CTX_add_extra_chain_cert: %s",
1250 ERR_error_string(ERR_get_error(), NULL
));
1257 /* Logs fingerprint of CA certificate 'cert' obtained from 'file_name'. */
1259 log_ca_cert(const char *file_name
, X509
*cert
)
1261 unsigned char digest
[EVP_MAX_MD_SIZE
];
1262 unsigned int n_bytes
;
1267 if (!X509_digest(cert
, EVP_sha1(), digest
, &n_bytes
)) {
1268 ds_put_cstr(&fp
, "<out of memory>");
1271 for (i
= 0; i
< n_bytes
; i
++) {
1273 ds_put_char(&fp
, ':');
1275 ds_put_format(&fp
, "%02hhx", digest
[i
]);
1278 subject
= X509_NAME_oneline(X509_get_subject_name(cert
), NULL
, 0);
1279 VLOG_INFO("Trusting CA cert from %s (%s) (fingerprint %s)", file_name
,
1280 subject
? subject
: "<out of memory>", ds_cstr(&fp
));
1281 OPENSSL_free(subject
);
1286 stream_ssl_set_ca_cert_file__(const char *file_name
, bool bootstrap
)
1292 if (!strcmp(file_name
, "none")) {
1293 verify_peer_cert
= false;
1294 VLOG_WARN("Peer certificate validation disabled "
1295 "(this is a security risk)");
1296 } else if (bootstrap
&& stat(file_name
, &s
) && errno
== ENOENT
) {
1297 bootstrap_ca_cert
= true;
1298 } else if (!read_cert_file(file_name
, &certs
, &n_certs
)) {
1301 /* Set up list of CAs that the server will accept from the client. */
1302 for (i
= 0; i
< n_certs
; i
++) {
1303 /* SSL_CTX_add_client_CA makes a copy of the relevant data. */
1304 if (SSL_CTX_add_client_CA(ctx
, certs
[i
]) != 1) {
1305 VLOG_ERR("failed to add client certificate %zu from %s: %s",
1307 ERR_error_string(ERR_get_error(), NULL
));
1309 log_ca_cert(file_name
, certs
[i
]);
1311 X509_free(certs
[i
]);
1315 /* Set up CAs for OpenSSL to trust in verifying the peer's
1317 if (SSL_CTX_load_verify_locations(ctx
, file_name
, NULL
) != 1) {
1318 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
1319 ERR_error_string(ERR_get_error(), NULL
));
1323 bootstrap_ca_cert
= false;
1325 ca_cert
.read
= true;
1328 /* Sets 'file_name' as the name of the file from which to read the CA
1329 * certificate used to verify the peer within SSL connections. If 'bootstrap'
1330 * is false, the file must exist. If 'bootstrap' is false, then the file is
1331 * read if it is exists; if it does not, then it will be created from the CA
1332 * certificate received from the peer on the first SSL connection. */
1334 stream_ssl_set_ca_cert_file(const char *file_name
, bool bootstrap
)
1336 if (!update_ssl_config(&ca_cert
, file_name
)) {
1340 stream_ssl_set_ca_cert_file__(file_name
, bootstrap
);
1343 /* SSL protocol logging. */
1346 ssl_alert_level_to_string(uint8_t type
)
1349 case 1: return "warning";
1350 case 2: return "fatal";
1351 default: return "<unknown>";
1356 ssl_alert_description_to_string(uint8_t type
)
1359 case 0: return "close_notify";
1360 case 10: return "unexpected_message";
1361 case 20: return "bad_record_mac";
1362 case 21: return "decryption_failed";
1363 case 22: return "record_overflow";
1364 case 30: return "decompression_failure";
1365 case 40: return "handshake_failure";
1366 case 42: return "bad_certificate";
1367 case 43: return "unsupported_certificate";
1368 case 44: return "certificate_revoked";
1369 case 45: return "certificate_expired";
1370 case 46: return "certificate_unknown";
1371 case 47: return "illegal_parameter";
1372 case 48: return "unknown_ca";
1373 case 49: return "access_denied";
1374 case 50: return "decode_error";
1375 case 51: return "decrypt_error";
1376 case 60: return "export_restriction";
1377 case 70: return "protocol_version";
1378 case 71: return "insufficient_security";
1379 case 80: return "internal_error";
1380 case 90: return "user_canceled";
1381 case 100: return "no_renegotiation";
1382 default: return "<unknown>";
1387 ssl_handshake_type_to_string(uint8_t type
)
1390 case 0: return "hello_request";
1391 case 1: return "client_hello";
1392 case 2: return "server_hello";
1393 case 11: return "certificate";
1394 case 12: return "server_key_exchange";
1395 case 13: return "certificate_request";
1396 case 14: return "server_hello_done";
1397 case 15: return "certificate_verify";
1398 case 16: return "client_key_exchange";
1399 case 20: return "finished";
1400 default: return "<unknown>";
1405 ssl_protocol_cb(int write_p
, int version OVS_UNUSED
, int content_type
,
1406 const void *buf_
, size_t len
, SSL
*ssl OVS_UNUSED
, void *sslv_
)
1408 const struct ssl_stream
*sslv
= sslv_
;
1409 const uint8_t *buf
= buf_
;
1412 if (!VLOG_IS_DBG_ENABLED()) {
1417 if (content_type
== 20) {
1418 ds_put_cstr(&details
, "change_cipher_spec");
1419 } else if (content_type
== 21) {
1420 ds_put_format(&details
, "alert: %s, %s",
1421 ssl_alert_level_to_string(buf
[0]),
1422 ssl_alert_description_to_string(buf
[1]));
1423 } else if (content_type
== 22) {
1424 ds_put_format(&details
, "handshake: %s",
1425 ssl_handshake_type_to_string(buf
[0]));
1427 ds_put_format(&details
, "type %d", content_type
);
1430 VLOG_DBG("%s%u%s%s %s (%zu bytes)",
1431 sslv
->type
== CLIENT
? "client" : "server",
1432 sslv
->session_nr
, write_p
? "-->" : "<--",
1433 stream_get_name(&sslv
->stream
), ds_cstr(&details
), len
);
1435 ds_destroy(&details
);