2 * Copyright (c) 2008, 2009, 2010, 2011 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 <sys/types.h>
26 #include <sys/socket.h>
27 #include <netinet/tcp.h>
28 #include <openssl/err.h>
29 #include <openssl/ssl.h>
30 #include <openssl/x509v3.h>
32 #include <sys/fcntl.h>
36 #include "dynamic-string.h"
37 #include "leak-checker.h"
39 #include "openflow/openflow.h"
41 #include "poll-loop.h"
43 #include "socket-util.h"
45 #include "stream-provider.h"
50 VLOG_DEFINE_THIS_MODULE(stream_ssl
);
68 enum session_type type
;
72 unsigned int session_nr
;
74 /* rx_want and tx_want record the result of the last call to SSL_read()
75 * and SSL_write(), respectively:
77 * - If the call reported that data needed to be read from the file
78 * descriptor, the corresponding member is set to SSL_READING.
80 * - If the call reported that data needed to be written to the file
81 * descriptor, the corresponding member is set to SSL_WRITING.
83 * - Otherwise, the member is set to SSL_NOTHING, indicating that the
84 * call completed successfully (or with an error) and that there is no
87 * These are needed because there is no way to ask OpenSSL what a data read
88 * or write would require without giving it a buffer to receive into or
89 * data to send, respectively. (Note that the SSL_want() status is
90 * overwritten by each SSL_read() or SSL_write() call, so we can't rely on
93 * A single call to SSL_read() or SSL_write() can perform both reading
94 * and writing and thus invalidate not one of these values but actually
95 * both. Consider this situation, for example:
97 * - SSL_write() blocks on a read, so tx_want gets SSL_READING.
99 * - SSL_read() laters succeeds reading from 'fd' and clears out the
100 * whole receive buffer, so rx_want gets SSL_READING.
102 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
105 * - Now we're stuck blocking until the peer sends us data, even though
106 * SSL_write() could now succeed, which could easily be a deadlock
109 * On the other hand, we can't reset both tx_want and rx_want on every call
110 * to SSL_read() or SSL_write(), because that would produce livelock,
111 * e.g. in this situation:
113 * - SSL_write() blocks, so tx_want gets SSL_READING or SSL_WRITING.
115 * - SSL_read() blocks, so rx_want gets SSL_READING or SSL_WRITING,
116 * but tx_want gets reset to SSL_NOTHING.
118 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
121 * - Client wakes up immediately since SSL_NOTHING in tx_want indicates
122 * that no blocking is necessary.
124 * The solution we adopt here is to set tx_want to SSL_NOTHING after
125 * calling SSL_read() only if the SSL state of the connection changed,
126 * which indicates that an SSL-level renegotiation made some progress, and
127 * similarly for rx_want and SSL_write(). This prevents both the
128 * deadlock and livelock situations above.
130 int rx_want
, tx_want
;
132 /* A few bytes of header data in case SSL negotiation fails. */
137 /* SSL context created by ssl_init(). */
140 struct ssl_config_file
{
141 bool read
; /* Whether the file was successfully read. */
142 char *file_name
; /* Configured file name, if any. */
143 struct timespec mtime
; /* File mtime as of last time we read it. */
146 /* SSL configuration files. */
147 static struct ssl_config_file private_key
;
148 static struct ssl_config_file certificate
;
149 static struct ssl_config_file ca_cert
;
151 /* Ordinarily, the SSL client and server verify each other's certificates using
152 * a CA certificate. Setting this to false disables this behavior. (This is a
154 static bool verify_peer_cert
= true;
156 /* Ordinarily, we require a CA certificate for the peer to be locally
157 * available. We can, however, bootstrap the CA certificate from the peer at
158 * the beginning of our first connection then use that certificate on all
159 * subsequent connections, saving it to a file for use in future runs also. In
160 * this case, 'bootstrap_ca_cert' is true. */
161 static bool bootstrap_ca_cert
;
163 /* Session number. Used in debug logging messages to uniquely identify a
165 static unsigned int next_session_nr
;
167 /* Who knows what can trigger various SSL errors, so let's throttle them down
169 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(10, 25);
171 static int ssl_init(void);
172 static int do_ssl_init(void);
173 static bool ssl_wants_io(int ssl_error
);
174 static void ssl_close(struct stream
*);
175 static void ssl_clear_txbuf(struct ssl_stream
*);
176 static void interpret_queued_ssl_error(const char *function
);
177 static int interpret_ssl_error(const char *function
, int ret
, int error
,
179 static DH
*tmp_dh_callback(SSL
*ssl
, int is_export OVS_UNUSED
, int keylength
);
180 static void log_ca_cert(const char *file_name
, X509
*cert
);
181 static void stream_ssl_set_ca_cert_file__(const char *file_name
,
182 bool bootstrap
, bool force
);
183 static void ssl_protocol_cb(int write_p
, int version
, int content_type
,
184 const void *, size_t, SSL
*, void *sslv_
);
185 static bool update_ssl_config(struct ssl_config_file
*, const char *file_name
);
188 want_to_poll_events(int want
)
206 new_ssl_stream(const char *name
, int fd
, enum session_type type
,
207 enum ssl_state state
, const struct sockaddr_in
*remote
,
208 struct stream
**streamp
)
210 struct sockaddr_in local
;
211 socklen_t local_len
= sizeof local
;
212 struct ssl_stream
*sslv
;
217 /* Check for all the needful configuration. */
219 if (!private_key
.read
) {
220 VLOG_ERR("Private key must be configured to use SSL");
221 retval
= ENOPROTOOPT
;
223 if (!certificate
.read
) {
224 VLOG_ERR("Certificate must be configured to use SSL");
225 retval
= ENOPROTOOPT
;
227 if (!ca_cert
.read
&& verify_peer_cert
&& !bootstrap_ca_cert
) {
228 VLOG_ERR("CA certificate must be configured to use SSL");
229 retval
= ENOPROTOOPT
;
231 if (!SSL_CTX_check_private_key(ctx
)) {
232 VLOG_ERR("Private key does not match certificate public key: %s",
233 ERR_error_string(ERR_get_error(), NULL
));
234 retval
= ENOPROTOOPT
;
240 /* Get the local IP and port information */
241 retval
= getsockname(fd
, (struct sockaddr
*) &local
, &local_len
);
243 memset(&local
, 0, sizeof local
);
247 retval
= setsockopt(fd
, IPPROTO_TCP
, TCP_NODELAY
, &on
, sizeof on
);
249 VLOG_ERR("%s: setsockopt(TCP_NODELAY): %s", name
, strerror(errno
));
254 /* Create and configure OpenSSL stream. */
257 VLOG_ERR("SSL_new: %s", ERR_error_string(ERR_get_error(), NULL
));
258 retval
= ENOPROTOOPT
;
261 if (SSL_set_fd(ssl
, fd
) == 0) {
262 VLOG_ERR("SSL_set_fd: %s", ERR_error_string(ERR_get_error(), NULL
));
263 retval
= ENOPROTOOPT
;
266 if (!verify_peer_cert
|| (bootstrap_ca_cert
&& type
== CLIENT
)) {
267 SSL_set_verify(ssl
, SSL_VERIFY_NONE
, NULL
);
270 /* Create and return the ssl_stream. */
271 sslv
= xmalloc(sizeof *sslv
);
272 stream_init(&sslv
->stream
, &ssl_stream_class
, EAGAIN
, name
);
273 stream_set_remote_ip(&sslv
->stream
, remote
->sin_addr
.s_addr
);
274 stream_set_remote_port(&sslv
->stream
, remote
->sin_port
);
275 stream_set_local_ip(&sslv
->stream
, local
.sin_addr
.s_addr
);
276 stream_set_local_port(&sslv
->stream
, local
.sin_port
);
282 sslv
->rx_want
= sslv
->tx_want
= SSL_NOTHING
;
283 sslv
->session_nr
= next_session_nr
++;
286 if (VLOG_IS_DBG_ENABLED()) {
287 SSL_set_msg_callback(ssl
, ssl_protocol_cb
);
288 SSL_set_msg_callback_arg(ssl
, sslv
);
291 *streamp
= &sslv
->stream
;
302 static struct ssl_stream
*
303 ssl_stream_cast(struct stream
*stream
)
305 stream_assert_class(stream
, &ssl_stream_class
);
306 return CONTAINER_OF(stream
, struct ssl_stream
, stream
);
310 ssl_open(const char *name
, char *suffix
, struct stream
**streamp
)
312 struct sockaddr_in sin
;
320 error
= inet_open_active(SOCK_STREAM
, suffix
, OFP_SSL_PORT
, &sin
, &fd
);
322 int state
= error
? STATE_TCP_CONNECTING
: STATE_SSL_CONNECTING
;
323 return new_ssl_stream(name
, fd
, CLIENT
, state
, &sin
, streamp
);
325 VLOG_ERR("%s: connect: %s", name
, strerror(error
));
331 do_ca_cert_bootstrap(struct stream
*stream
)
333 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
334 STACK_OF(X509
) *chain
;
340 chain
= SSL_get_peer_cert_chain(sslv
->ssl
);
341 if (!chain
|| !sk_X509_num(chain
)) {
342 VLOG_ERR("could not bootstrap CA cert: no certificate presented by "
346 cert
= sk_X509_value(chain
, sk_X509_num(chain
) - 1);
348 /* Check that 'cert' is self-signed. Otherwise it is not a CA
349 * certificate and we should not attempt to use it as one. */
350 error
= X509_check_issued(cert
, cert
);
352 VLOG_ERR("could not bootstrap CA cert: obtained certificate is "
353 "not self-signed (%s)",
354 X509_verify_cert_error_string(error
));
355 if (sk_X509_num(chain
) < 2) {
356 VLOG_ERR("only one certificate was received, so probably the peer "
357 "is not configured to send its CA certificate");
362 fd
= open(ca_cert
.file_name
, O_CREAT
| O_EXCL
| O_WRONLY
, 0444);
364 if (errno
== EEXIST
) {
365 VLOG_INFO_RL(&rl
, "reading CA cert %s created by another process",
367 stream_ssl_set_ca_cert_file__(ca_cert
.file_name
, true, true);
370 VLOG_ERR("could not bootstrap CA cert: creating %s failed: %s",
371 ca_cert
.file_name
, strerror(errno
));
376 file
= fdopen(fd
, "w");
379 VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s",
381 unlink(ca_cert
.file_name
);
385 if (!PEM_write_X509(file
, cert
)) {
386 VLOG_ERR("could not bootstrap CA cert: PEM_write_X509 to %s failed: "
387 "%s", ca_cert
.file_name
,
388 ERR_error_string(ERR_get_error(), NULL
));
390 unlink(ca_cert
.file_name
);
396 VLOG_ERR("could not bootstrap CA cert: writing %s failed: %s",
397 ca_cert
.file_name
, strerror(error
));
398 unlink(ca_cert
.file_name
);
402 VLOG_INFO("successfully bootstrapped CA cert to %s", ca_cert
.file_name
);
403 log_ca_cert(ca_cert
.file_name
, cert
);
404 bootstrap_ca_cert
= false;
407 /* SSL_CTX_add_client_CA makes a copy of cert's relevant data. */
408 SSL_CTX_add_client_CA(ctx
, cert
);
410 /* SSL_CTX_use_certificate() takes ownership of the certificate passed in.
411 * 'cert' is owned by sslv->ssl, so we need to duplicate it. */
412 cert
= X509_dup(cert
);
416 SSL_CTX_set_cert_store(ctx
, X509_STORE_new());
417 if (SSL_CTX_load_verify_locations(ctx
, ca_cert
.file_name
, NULL
) != 1) {
418 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
419 ERR_error_string(ERR_get_error(), NULL
));
422 VLOG_INFO("killing successful connection to retry using CA cert");
427 ssl_connect(struct stream
*stream
)
429 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
432 switch (sslv
->state
) {
433 case STATE_TCP_CONNECTING
:
434 retval
= check_connection_completion(sslv
->fd
);
438 sslv
->state
= STATE_SSL_CONNECTING
;
441 case STATE_SSL_CONNECTING
:
442 /* Capture the first few bytes of received data so that we can guess
443 * what kind of funny data we've been sent if SSL negotation fails. */
444 if (sslv
->n_head
<= 0) {
445 sslv
->n_head
= recv(sslv
->fd
, sslv
->head
, sizeof sslv
->head
,
449 retval
= (sslv
->type
== CLIENT
450 ? SSL_connect(sslv
->ssl
) : SSL_accept(sslv
->ssl
));
452 int error
= SSL_get_error(sslv
->ssl
, retval
);
453 if (retval
< 0 && ssl_wants_io(error
)) {
458 interpret_ssl_error((sslv
->type
== CLIENT
? "SSL_connect"
459 : "SSL_accept"), retval
, error
, &unused
);
460 shutdown(sslv
->fd
, SHUT_RDWR
);
461 stream_report_content(sslv
->head
, sslv
->n_head
, STREAM_SSL
,
462 THIS_MODULE
, stream_get_name(stream
));
465 } else if (bootstrap_ca_cert
) {
466 return do_ca_cert_bootstrap(stream
);
467 } else if (verify_peer_cert
468 && ((SSL_get_verify_mode(sslv
->ssl
)
469 & (SSL_VERIFY_NONE
| SSL_VERIFY_PEER
))
470 != SSL_VERIFY_PEER
)) {
471 /* Two or more SSL connections completed at the same time while we
472 * were in bootstrap mode. Only one of these can finish the
473 * bootstrap successfully. The other one(s) must be rejected
474 * because they were not verified against the bootstrapped CA
475 * certificate. (Alternatively we could verify them against the CA
476 * certificate, but that's more trouble than it's worth. These
477 * connections will succeed the next time they retry, assuming that
478 * they have a certificate against the correct CA.) */
479 VLOG_ERR("rejecting SSL connection during bootstrap race window");
490 ssl_close(struct stream
*stream
)
492 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
493 ssl_clear_txbuf(sslv
);
495 /* Attempt clean shutdown of the SSL connection. This will work most of
496 * the time, as long as the kernel send buffer has some free space and the
497 * SSL connection isn't renegotiating, etc. That has to be good enough,
498 * since we don't have any way to continue the close operation in the
500 SSL_shutdown(sslv
->ssl
);
502 /* SSL_shutdown() might have signaled an error, in which case we need to
503 * flush it out of the OpenSSL error queue or the next OpenSSL operation
504 * will falsely signal an error. */
513 interpret_queued_ssl_error(const char *function
)
515 int queued_error
= ERR_get_error();
516 if (queued_error
!= 0) {
517 VLOG_WARN_RL(&rl
, "%s: %s",
518 function
, ERR_error_string(queued_error
, NULL
));
520 VLOG_ERR_RL(&rl
, "%s: SSL_ERROR_SSL without queued error", function
);
525 interpret_ssl_error(const char *function
, int ret
, int error
,
532 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_NONE", function
);
535 case SSL_ERROR_ZERO_RETURN
:
536 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_ZERO_RETURN", function
);
539 case SSL_ERROR_WANT_READ
:
543 case SSL_ERROR_WANT_WRITE
:
547 case SSL_ERROR_WANT_CONNECT
:
548 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_WANT_CONNECT", function
);
551 case SSL_ERROR_WANT_ACCEPT
:
552 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_WANT_ACCEPT", function
);
555 case SSL_ERROR_WANT_X509_LOOKUP
:
556 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_WANT_X509_LOOKUP",
560 case SSL_ERROR_SYSCALL
: {
561 int queued_error
= ERR_get_error();
562 if (queued_error
== 0) {
565 VLOG_WARN_RL(&rl
, "%s: system error (%s)",
566 function
, strerror(status
));
569 VLOG_WARN_RL(&rl
, "%s: unexpected SSL connection close",
574 VLOG_WARN_RL(&rl
, "%s: %s",
575 function
, ERR_error_string(queued_error
, NULL
));
581 interpret_queued_ssl_error(function
);
585 VLOG_ERR_RL(&rl
, "%s: bad SSL error code %d", function
, error
);
592 ssl_recv(struct stream
*stream
, void *buffer
, size_t n
)
594 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
598 /* Behavior of zero-byte SSL_read is poorly defined. */
601 old_state
= SSL_get_state(sslv
->ssl
);
602 ret
= SSL_read(sslv
->ssl
, buffer
, n
);
603 if (old_state
!= SSL_get_state(sslv
->ssl
)) {
604 sslv
->tx_want
= SSL_NOTHING
;
606 sslv
->rx_want
= SSL_NOTHING
;
611 int error
= SSL_get_error(sslv
->ssl
, ret
);
612 if (error
== SSL_ERROR_ZERO_RETURN
) {
615 return -interpret_ssl_error("SSL_read", ret
, error
,
622 ssl_clear_txbuf(struct ssl_stream
*sslv
)
624 ofpbuf_delete(sslv
->txbuf
);
629 ssl_do_tx(struct stream
*stream
)
631 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
634 int old_state
= SSL_get_state(sslv
->ssl
);
635 int ret
= SSL_write(sslv
->ssl
, sslv
->txbuf
->data
, sslv
->txbuf
->size
);
636 if (old_state
!= SSL_get_state(sslv
->ssl
)) {
637 sslv
->rx_want
= SSL_NOTHING
;
639 sslv
->tx_want
= SSL_NOTHING
;
641 ofpbuf_pull(sslv
->txbuf
, ret
);
642 if (sslv
->txbuf
->size
== 0) {
646 int ssl_error
= SSL_get_error(sslv
->ssl
, ret
);
647 if (ssl_error
== SSL_ERROR_ZERO_RETURN
) {
648 VLOG_WARN_RL(&rl
, "SSL_write: connection closed");
651 return interpret_ssl_error("SSL_write", ret
, ssl_error
,
659 ssl_send(struct stream
*stream
, const void *buffer
, size_t n
)
661 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
668 sslv
->txbuf
= ofpbuf_clone_data(buffer
, n
);
669 error
= ssl_do_tx(stream
);
672 ssl_clear_txbuf(sslv
);
675 leak_checker_claim(buffer
);
685 ssl_run(struct stream
*stream
)
687 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
689 if (sslv
->txbuf
&& ssl_do_tx(stream
) != EAGAIN
) {
690 ssl_clear_txbuf(sslv
);
695 ssl_run_wait(struct stream
*stream
)
697 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
699 if (sslv
->tx_want
!= SSL_NOTHING
) {
700 poll_fd_wait(sslv
->fd
, want_to_poll_events(sslv
->tx_want
));
705 ssl_wait(struct stream
*stream
, enum stream_wait_type wait
)
707 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
711 if (stream_connect(stream
) != EAGAIN
) {
712 poll_immediate_wake();
714 switch (sslv
->state
) {
715 case STATE_TCP_CONNECTING
:
716 poll_fd_wait(sslv
->fd
, POLLOUT
);
719 case STATE_SSL_CONNECTING
:
720 /* ssl_connect() called SSL_accept() or SSL_connect(), which
721 * set up the status that we test here. */
722 poll_fd_wait(sslv
->fd
,
723 want_to_poll_events(SSL_want(sslv
->ssl
)));
733 if (sslv
->rx_want
!= SSL_NOTHING
) {
734 poll_fd_wait(sslv
->fd
, want_to_poll_events(sslv
->rx_want
));
736 poll_immediate_wake();
742 /* We have room in our tx queue. */
743 poll_immediate_wake();
745 /* stream_run_wait() will do the right thing; don't bother with
755 struct stream_class ssl_stream_class
= {
758 ssl_close
, /* close */
759 ssl_connect
, /* connect */
763 ssl_run_wait
, /* run_wait */
771 struct pstream pstream
;
775 struct pstream_class pssl_pstream_class
;
777 static struct pssl_pstream
*
778 pssl_pstream_cast(struct pstream
*pstream
)
780 pstream_assert_class(pstream
, &pssl_pstream_class
);
781 return CONTAINER_OF(pstream
, struct pssl_pstream
, pstream
);
785 pssl_open(const char *name OVS_UNUSED
, char *suffix
, struct pstream
**pstreamp
)
787 struct pssl_pstream
*pssl
;
788 struct sockaddr_in sin
;
789 char bound_name
[128];
798 fd
= inet_open_passive(SOCK_STREAM
, suffix
, OFP_SSL_PORT
, &sin
);
802 sprintf(bound_name
, "pssl:%"PRIu16
":"IP_FMT
,
803 ntohs(sin
.sin_port
), IP_ARGS(&sin
.sin_addr
.s_addr
));
805 pssl
= xmalloc(sizeof *pssl
);
806 pstream_init(&pssl
->pstream
, &pssl_pstream_class
, bound_name
);
808 *pstreamp
= &pssl
->pstream
;
813 pssl_close(struct pstream
*pstream
)
815 struct pssl_pstream
*pssl
= pssl_pstream_cast(pstream
);
821 pssl_accept(struct pstream
*pstream
, struct stream
**new_streamp
)
823 struct pssl_pstream
*pssl
= pssl_pstream_cast(pstream
);
824 struct sockaddr_in sin
;
825 socklen_t sin_len
= sizeof sin
;
830 new_fd
= accept(pssl
->fd
, (struct sockaddr
*) &sin
, &sin_len
);
833 if (error
!= EAGAIN
) {
834 VLOG_DBG_RL(&rl
, "accept: %s", strerror(error
));
839 error
= set_nonblocking(new_fd
);
845 sprintf(name
, "ssl:"IP_FMT
, IP_ARGS(&sin
.sin_addr
));
846 if (sin
.sin_port
!= htons(OFP_SSL_PORT
)) {
847 sprintf(strchr(name
, '\0'), ":%"PRIu16
, ntohs(sin
.sin_port
));
849 return new_ssl_stream(name
, new_fd
, SERVER
, STATE_SSL_CONNECTING
, &sin
,
854 pssl_wait(struct pstream
*pstream
)
856 struct pssl_pstream
*pssl
= pssl_pstream_cast(pstream
);
857 poll_fd_wait(pssl
->fd
, POLLIN
);
860 struct pstream_class pssl_pstream_class
= {
869 * Returns true if OpenSSL error is WANT_READ or WANT_WRITE, indicating that
870 * OpenSSL is requesting that we call it back when the socket is ready for read
871 * or writing, respectively.
874 ssl_wants_io(int ssl_error
)
876 return (ssl_error
== SSL_ERROR_WANT_WRITE
877 || ssl_error
== SSL_ERROR_WANT_READ
);
883 static int init_status
= -1;
884 if (init_status
< 0) {
885 init_status
= do_ssl_init();
886 assert(init_status
>= 0);
897 SSL_load_error_strings();
899 /* New OpenSSL changed TLSv1_method() to return a "const" pointer, so the
900 * cast is needed to avoid a warning with those newer versions. */
901 method
= (SSL_METHOD
*) TLSv1_method();
902 if (method
== NULL
) {
903 VLOG_ERR("TLSv1_method: %s", ERR_error_string(ERR_get_error(), NULL
));
907 ctx
= SSL_CTX_new(method
);
909 VLOG_ERR("SSL_CTX_new: %s", ERR_error_string(ERR_get_error(), NULL
));
912 SSL_CTX_set_options(ctx
, SSL_OP_NO_SSLv2
| SSL_OP_NO_SSLv3
);
913 SSL_CTX_set_tmp_dh_callback(ctx
, tmp_dh_callback
);
914 SSL_CTX_set_mode(ctx
, SSL_MODE_ENABLE_PARTIAL_WRITE
);
915 SSL_CTX_set_mode(ctx
, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER
);
916 SSL_CTX_set_verify(ctx
, SSL_VERIFY_PEER
| SSL_VERIFY_FAIL_IF_NO_PEER_CERT
,
923 tmp_dh_callback(SSL
*ssl OVS_UNUSED
, int is_export OVS_UNUSED
, int keylength
)
928 DH
*(*constructor
)(void);
931 static struct dh dh_table
[] = {
932 {1024, NULL
, get_dh1024
},
933 {2048, NULL
, get_dh2048
},
934 {4096, NULL
, get_dh4096
},
939 for (dh
= dh_table
; dh
< &dh_table
[ARRAY_SIZE(dh_table
)]; dh
++) {
940 if (dh
->keylength
== keylength
) {
942 dh
->dh
= dh
->constructor();
950 VLOG_ERR_RL(&rl
, "no Diffie-Hellman parameters for key length %d",
955 /* Returns true if SSL is at least partially configured. */
957 stream_ssl_is_configured(void)
959 return private_key
.file_name
|| certificate
.file_name
|| ca_cert
.file_name
;
963 update_ssl_config(struct ssl_config_file
*config
, const char *file_name
)
965 struct timespec mtime
;
968 if (ssl_init() || !file_name
) {
972 /* If the file name hasn't changed and neither has the file contents, stop
974 error
= get_mtime(file_name
, &mtime
);
975 if (error
&& error
!= ENOENT
) {
976 VLOG_ERR_RL(&rl
, "%s: stat failed (%s)", file_name
, strerror(error
));
978 if (config
->file_name
979 && !strcmp(config
->file_name
, file_name
)
980 && mtime
.tv_sec
== config
->mtime
.tv_sec
981 && mtime
.tv_nsec
== config
->mtime
.tv_nsec
) {
985 /* Update 'config'. */
986 config
->mtime
= mtime
;
987 if (file_name
!= config
->file_name
) {
988 free(config
->file_name
);
989 config
->file_name
= xstrdup(file_name
);
995 stream_ssl_set_private_key_file__(const char *file_name
)
997 if (SSL_CTX_use_PrivateKey_file(ctx
, file_name
, SSL_FILETYPE_PEM
) == 1) {
998 private_key
.read
= true;
1000 VLOG_ERR("SSL_use_PrivateKey_file: %s",
1001 ERR_error_string(ERR_get_error(), NULL
));
1006 stream_ssl_set_private_key_file(const char *file_name
)
1008 if (update_ssl_config(&private_key
, file_name
)) {
1009 stream_ssl_set_private_key_file__(file_name
);
1014 stream_ssl_set_certificate_file__(const char *file_name
)
1016 if (SSL_CTX_use_certificate_chain_file(ctx
, file_name
) == 1) {
1017 certificate
.read
= true;
1019 VLOG_ERR("SSL_use_certificate_file: %s",
1020 ERR_error_string(ERR_get_error(), NULL
));
1025 stream_ssl_set_certificate_file(const char *file_name
)
1027 if (update_ssl_config(&certificate
, file_name
)) {
1028 stream_ssl_set_certificate_file__(file_name
);
1032 /* Sets the private key and certificate files in one operation. Use this
1033 * interface, instead of calling stream_ssl_set_private_key_file() and
1034 * stream_ssl_set_certificate_file() individually, in the main loop of a
1035 * long-running program whose key and certificate might change at runtime.
1037 * This is important because of OpenSSL's behavior. If an OpenSSL context
1038 * already has a certificate, and stream_ssl_set_private_key_file() is called
1039 * to install a new private key, OpenSSL will report an error because the new
1040 * private key does not match the old certificate. The other order, of setting
1041 * a new certificate, then setting a new private key, does work.
1043 * If this were the only problem, calling stream_ssl_set_certificate_file()
1044 * before stream_ssl_set_private_key_file() would fix it. But, if the private
1045 * key is changed before the certificate (e.g. someone "scp"s or "mv"s the new
1046 * private key in place before the certificate), then OpenSSL would reject that
1047 * change, and then the change of certificate would succeed, but there would be
1048 * no associated private key (because it had only changed once and therefore
1049 * there was no point in re-reading it).
1051 * This function avoids both problems by, whenever either the certificate or
1052 * the private key file changes, re-reading both of them, in the correct order.
1055 stream_ssl_set_key_and_cert(const char *private_key_file
,
1056 const char *certificate_file
)
1058 if (update_ssl_config(&private_key
, private_key_file
)
1059 || update_ssl_config(&certificate
, certificate_file
)) {
1060 stream_ssl_set_certificate_file__(certificate_file
);
1061 stream_ssl_set_private_key_file__(private_key_file
);
1065 /* Reads the X509 certificate or certificates in file 'file_name'. On success,
1066 * stores the address of the first element in an array of pointers to
1067 * certificates in '*certs' and the number of certificates in the array in
1068 * '*n_certs', and returns 0. On failure, stores a null pointer in '*certs', 0
1069 * in '*n_certs', and returns a positive errno value.
1071 * The caller is responsible for freeing '*certs'. */
1073 read_cert_file(const char *file_name
, X509
***certs
, size_t *n_certs
)
1076 size_t allocated_certs
= 0;
1081 file
= fopen(file_name
, "r");
1083 VLOG_ERR("failed to open %s for reading: %s",
1084 file_name
, strerror(errno
));
1092 /* Read certificate from file. */
1093 certificate
= PEM_read_X509(file
, NULL
, NULL
, NULL
);
1097 VLOG_ERR("PEM_read_X509 failed reading %s: %s",
1098 file_name
, ERR_error_string(ERR_get_error(), NULL
));
1099 for (i
= 0; i
< *n_certs
; i
++) {
1100 X509_free((*certs
)[i
]);
1108 /* Add certificate to array. */
1109 if (*n_certs
>= allocated_certs
) {
1110 *certs
= x2nrealloc(*certs
, &allocated_certs
, sizeof **certs
);
1112 (*certs
)[(*n_certs
)++] = certificate
;
1114 /* Are there additional certificates in the file? */
1117 } while (isspace(c
));
1128 /* Sets 'file_name' as the name of a file containing one or more X509
1129 * certificates to send to the peer. Typical use in OpenFlow is to send the CA
1130 * certificate to the peer, which enables a switch to pick up the controller's
1131 * CA certificate on its first connection. */
1133 stream_ssl_set_peer_ca_cert_file(const char *file_name
)
1143 if (!read_cert_file(file_name
, &certs
, &n_certs
)) {
1144 for (i
= 0; i
< n_certs
; i
++) {
1145 if (SSL_CTX_add_extra_chain_cert(ctx
, certs
[i
]) != 1) {
1146 VLOG_ERR("SSL_CTX_add_extra_chain_cert: %s",
1147 ERR_error_string(ERR_get_error(), NULL
));
1154 /* Logs fingerprint of CA certificate 'cert' obtained from 'file_name'. */
1156 log_ca_cert(const char *file_name
, X509
*cert
)
1158 unsigned char digest
[EVP_MAX_MD_SIZE
];
1159 unsigned int n_bytes
;
1164 if (!X509_digest(cert
, EVP_sha1(), digest
, &n_bytes
)) {
1165 ds_put_cstr(&fp
, "<out of memory>");
1168 for (i
= 0; i
< n_bytes
; i
++) {
1170 ds_put_char(&fp
, ':');
1172 ds_put_format(&fp
, "%02hhx", digest
[i
]);
1175 subject
= X509_NAME_oneline(X509_get_subject_name(cert
), NULL
, 0);
1176 VLOG_INFO("Trusting CA cert from %s (%s) (fingerprint %s)", file_name
,
1177 subject
? subject
: "<out of memory>", ds_cstr(&fp
));
1178 OPENSSL_free(subject
);
1183 stream_ssl_set_ca_cert_file__(const char *file_name
,
1184 bool bootstrap
, bool force
)
1190 if (!update_ssl_config(&ca_cert
, file_name
) && !force
) {
1194 if (!strcmp(file_name
, "none")) {
1195 verify_peer_cert
= false;
1196 VLOG_WARN("Peer certificate validation disabled "
1197 "(this is a security risk)");
1198 } else if (bootstrap
&& stat(file_name
, &s
) && errno
== ENOENT
) {
1199 bootstrap_ca_cert
= true;
1200 } else if (!read_cert_file(file_name
, &certs
, &n_certs
)) {
1203 /* Set up list of CAs that the server will accept from the client. */
1204 for (i
= 0; i
< n_certs
; i
++) {
1205 /* SSL_CTX_add_client_CA makes a copy of the relevant data. */
1206 if (SSL_CTX_add_client_CA(ctx
, certs
[i
]) != 1) {
1207 VLOG_ERR("failed to add client certificate %zu from %s: %s",
1209 ERR_error_string(ERR_get_error(), NULL
));
1211 log_ca_cert(file_name
, certs
[i
]);
1213 X509_free(certs
[i
]);
1217 /* Set up CAs for OpenSSL to trust in verifying the peer's
1219 SSL_CTX_set_cert_store(ctx
, X509_STORE_new());
1220 if (SSL_CTX_load_verify_locations(ctx
, file_name
, NULL
) != 1) {
1221 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
1222 ERR_error_string(ERR_get_error(), NULL
));
1226 bootstrap_ca_cert
= false;
1228 ca_cert
.read
= true;
1231 /* Sets 'file_name' as the name of the file from which to read the CA
1232 * certificate used to verify the peer within SSL connections. If 'bootstrap'
1233 * is false, the file must exist. If 'bootstrap' is false, then the file is
1234 * read if it is exists; if it does not, then it will be created from the CA
1235 * certificate received from the peer on the first SSL connection. */
1237 stream_ssl_set_ca_cert_file(const char *file_name
, bool bootstrap
)
1239 stream_ssl_set_ca_cert_file__(file_name
, bootstrap
, false);
1242 /* SSL protocol logging. */
1245 ssl_alert_level_to_string(uint8_t type
)
1248 case 1: return "warning";
1249 case 2: return "fatal";
1250 default: return "<unknown>";
1255 ssl_alert_description_to_string(uint8_t type
)
1258 case 0: return "close_notify";
1259 case 10: return "unexpected_message";
1260 case 20: return "bad_record_mac";
1261 case 21: return "decryption_failed";
1262 case 22: return "record_overflow";
1263 case 30: return "decompression_failure";
1264 case 40: return "handshake_failure";
1265 case 42: return "bad_certificate";
1266 case 43: return "unsupported_certificate";
1267 case 44: return "certificate_revoked";
1268 case 45: return "certificate_expired";
1269 case 46: return "certificate_unknown";
1270 case 47: return "illegal_parameter";
1271 case 48: return "unknown_ca";
1272 case 49: return "access_denied";
1273 case 50: return "decode_error";
1274 case 51: return "decrypt_error";
1275 case 60: return "export_restriction";
1276 case 70: return "protocol_version";
1277 case 71: return "insufficient_security";
1278 case 80: return "internal_error";
1279 case 90: return "user_canceled";
1280 case 100: return "no_renegotiation";
1281 default: return "<unknown>";
1286 ssl_handshake_type_to_string(uint8_t type
)
1289 case 0: return "hello_request";
1290 case 1: return "client_hello";
1291 case 2: return "server_hello";
1292 case 11: return "certificate";
1293 case 12: return "server_key_exchange";
1294 case 13: return "certificate_request";
1295 case 14: return "server_hello_done";
1296 case 15: return "certificate_verify";
1297 case 16: return "client_key_exchange";
1298 case 20: return "finished";
1299 default: return "<unknown>";
1304 ssl_protocol_cb(int write_p
, int version OVS_UNUSED
, int content_type
,
1305 const void *buf_
, size_t len
, SSL
*ssl OVS_UNUSED
, void *sslv_
)
1307 const struct ssl_stream
*sslv
= sslv_
;
1308 const uint8_t *buf
= buf_
;
1311 if (!VLOG_IS_DBG_ENABLED()) {
1316 if (content_type
== 20) {
1317 ds_put_cstr(&details
, "change_cipher_spec");
1318 } else if (content_type
== 21) {
1319 ds_put_format(&details
, "alert: %s, %s",
1320 ssl_alert_level_to_string(buf
[0]),
1321 ssl_alert_description_to_string(buf
[1]));
1322 } else if (content_type
== 22) {
1323 ds_put_format(&details
, "handshake: %s",
1324 ssl_handshake_type_to_string(buf
[0]));
1326 ds_put_format(&details
, "type %d", content_type
);
1329 VLOG_DBG("%s%u%s%s %s (%zu bytes)",
1330 sslv
->type
== CLIENT
? "client" : "server",
1331 sslv
->session_nr
, write_p
? "-->" : "<--",
1332 stream_get_name(&sslv
->stream
), ds_cstr(&details
), len
);
1334 ds_destroy(&details
);