2 * Copyright (c) 2008-2016, 2019 Nicira, Inc.
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"
24 #include <sys/types.h>
25 #include <sys/socket.h>
26 #include <netinet/tcp.h>
27 #include <openssl/err.h>
28 #include <openssl/rand.h>
29 #include <openssl/ssl.h>
30 #include <openssl/x509v3.h>
36 #include "openvswitch/dynamic-string.h"
38 #include "openvswitch/ofpbuf.h"
39 #include "openflow/openflow.h"
41 #include "openvswitch/poll-loop.h"
42 #include "openvswitch/shash.h"
43 #include "socket-util.h"
45 #include "stream-provider.h"
48 #include "openvswitch/vlog.h"
51 /* Ref: https://www.openssl.org/support/faq.html#PROG2
52 * Your application must link against the same version of the Win32 C-Runtime
53 * against which your openssl libraries were linked. The default version for
54 * OpenSSL is /MD - "Multithreaded DLL". If we compile Open vSwitch with
55 * something other than /MD, instead of re-compiling OpenSSL
56 * toolkit, openssl/applink.c can be #included. Also, it is important
57 * to add CRYPTO_malloc_init prior first call to OpenSSL.
59 * XXX: The behavior of the following #include when Open vSwitch is
60 * compiled with /MD is not tested. */
61 #include <openssl/applink.c>
62 #define SHUT_RDWR SD_BOTH
65 VLOG_DEFINE_THIS_MODULE(stream_ssl
);
83 enum session_type type
;
87 unsigned int session_nr
;
89 /* rx_want and tx_want record the result of the last call to SSL_read()
90 * and SSL_write(), respectively:
92 * - If the call reported that data needed to be read from the file
93 * descriptor, the corresponding member is set to SSL_READING.
95 * - If the call reported that data needed to be written to the file
96 * descriptor, the corresponding member is set to SSL_WRITING.
98 * - Otherwise, the member is set to SSL_NOTHING, indicating that the
99 * call completed successfully (or with an error) and that there is no
102 * These are needed because there is no way to ask OpenSSL what a data read
103 * or write would require without giving it a buffer to receive into or
104 * data to send, respectively. (Note that the SSL_want() status is
105 * overwritten by each SSL_read() or SSL_write() call, so we can't rely on
108 * A single call to SSL_read() or SSL_write() can perform both reading
109 * and writing and thus invalidate not one of these values but actually
110 * both. Consider this situation, for example:
112 * - SSL_write() blocks on a read, so tx_want gets SSL_READING.
114 * - SSL_read() laters succeeds reading from 'fd' and clears out the
115 * whole receive buffer, so rx_want gets SSL_READING.
117 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
120 * - Now we're stuck blocking until the peer sends us data, even though
121 * SSL_write() could now succeed, which could easily be a deadlock
124 * On the other hand, we can't reset both tx_want and rx_want on every call
125 * to SSL_read() or SSL_write(), because that would produce livelock,
126 * e.g. in this situation:
128 * - SSL_write() blocks, so tx_want gets SSL_READING or SSL_WRITING.
130 * - SSL_read() blocks, so rx_want gets SSL_READING or SSL_WRITING,
131 * but tx_want gets reset to SSL_NOTHING.
133 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
136 * - Client wakes up immediately since SSL_NOTHING in tx_want indicates
137 * that no blocking is necessary.
139 * The solution we adopt here is to set tx_want to SSL_NOTHING after
140 * calling SSL_read() only if the SSL state of the connection changed,
141 * which indicates that an SSL-level renegotiation made some progress, and
142 * similarly for rx_want and SSL_write(). This prevents both the
143 * deadlock and livelock situations above.
145 int rx_want
, tx_want
;
147 /* A few bytes of header data in case SSL negotiation fails. */
152 /* SSL context created by ssl_init(). */
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
;
165 static char *ssl_protocols
= "TLSv1,TLSv1.1,TLSv1.2";
166 static char *ssl_ciphers
= "HIGH:!aNULL:!MD5";
168 /* Ordinarily, the SSL client and server verify each other's certificates using
169 * a CA certificate. Setting this to false disables this behavior. (This is a
171 static bool verify_peer_cert
= true;
173 /* Ordinarily, we require a CA certificate for the peer to be locally
174 * available. We can, however, bootstrap the CA certificate from the peer at
175 * the beginning of our first connection then use that certificate on all
176 * subsequent connections, saving it to a file for use in future runs also. In
177 * this case, 'bootstrap_ca_cert' is true. */
178 static bool bootstrap_ca_cert
;
180 /* Session number. Used in debug logging messages to uniquely identify a
182 static unsigned int next_session_nr
;
184 /* Who knows what can trigger various SSL errors, so let's throttle them down
186 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(10, 25);
188 static int ssl_init(void);
189 static int do_ssl_init(void);
190 static bool ssl_wants_io(int ssl_error
);
191 static void ssl_close(struct stream
*);
192 static void ssl_clear_txbuf(struct ssl_stream
*);
193 static void interpret_queued_ssl_error(const char *function
);
194 static int interpret_ssl_error(const char *function
, int ret
, int error
,
196 static DH
*tmp_dh_callback(SSL
*ssl
, int is_export OVS_UNUSED
, int keylength
);
197 static void log_ca_cert(const char *file_name
, X509
*cert
);
198 static void stream_ssl_set_ca_cert_file__(const char *file_name
,
199 bool bootstrap
, bool force
);
200 static void ssl_protocol_cb(int write_p
, int version
, int content_type
,
201 const void *, size_t, SSL
*, void *sslv_
);
202 static bool update_ssl_config(struct ssl_config_file
*, const char *file_name
);
203 static int sock_errno(void);
206 want_to_poll_events(int want
)
223 /* Creates a new SSL connection based on socket 'fd', as either a client or a
224 * server according to 'type', initially in 'state'. On success, returns 0 and
225 * stores the new stream in '*streamp', otherwise returns an errno value and
226 * doesn't bother with '*streamp'.
228 * Takes ownership of 'name', which should be the name of the connection in the
229 * format that would be used to connect to it, e.g. "ssl:1.2.3.4:5".
231 * For client connections, 'server_name' should be the host name of the server
232 * being connected to, for use with SSL SNI (server name indication). Takes
233 * ownership of 'server_name'. */
235 new_ssl_stream(char *name
, char *server_name
, int fd
, enum session_type type
,
236 enum ssl_state state
, struct stream
**streamp
)
238 struct ssl_stream
*sslv
;
242 /* Check for all the needful configuration. */
244 if (!private_key
.read
) {
245 VLOG_ERR("Private key must be configured to use SSL");
246 retval
= ENOPROTOOPT
;
248 if (!certificate
.read
) {
249 VLOG_ERR("Certificate must be configured to use SSL");
250 retval
= ENOPROTOOPT
;
252 if (!ca_cert
.read
&& verify_peer_cert
&& !bootstrap_ca_cert
) {
253 VLOG_ERR("CA certificate must be configured to use SSL");
254 retval
= ENOPROTOOPT
;
256 if (!retval
&& !SSL_CTX_check_private_key(ctx
)) {
257 VLOG_ERR("Private key does not match certificate public key: %s",
258 ERR_error_string(ERR_get_error(), NULL
));
259 retval
= ENOPROTOOPT
;
266 * On windows platforms, this can only be called upon TCP connected.
268 if (state
== STATE_SSL_CONNECTING
) {
269 setsockopt_tcp_nodelay(fd
);
272 /* Create and configure OpenSSL stream. */
275 VLOG_ERR("SSL_new: %s", ERR_error_string(ERR_get_error(), NULL
));
276 retval
= ENOPROTOOPT
;
279 if (SSL_set_fd(ssl
, fd
) == 0) {
280 VLOG_ERR("SSL_set_fd: %s", ERR_error_string(ERR_get_error(), NULL
));
281 retval
= ENOPROTOOPT
;
284 if (!verify_peer_cert
|| (bootstrap_ca_cert
&& type
== CLIENT
)) {
285 SSL_set_verify(ssl
, SSL_VERIFY_NONE
, NULL
);
287 #if OPENSSL_SUPPORTS_SNI
288 if (server_name
&& !SSL_set_tlsext_host_name(ssl
, server_name
)) {
289 VLOG_ERR("%s: failed to set server name indication (%s)",
290 server_name
, ERR_error_string(ERR_get_error(), NULL
));
291 retval
= ENOPROTOOPT
;
296 /* Create and return the ssl_stream. */
297 sslv
= xmalloc(sizeof *sslv
);
298 stream_init(&sslv
->stream
, &ssl_stream_class
, EAGAIN
, name
);
304 sslv
->rx_want
= sslv
->tx_want
= SSL_NOTHING
;
305 sslv
->session_nr
= next_session_nr
++;
308 if (VLOG_IS_DBG_ENABLED()) {
309 SSL_set_msg_callback(ssl
, ssl_protocol_cb
);
310 SSL_set_msg_callback_arg(ssl
, sslv
);
313 *streamp
= &sslv
->stream
;
327 static struct ssl_stream
*
328 ssl_stream_cast(struct stream
*stream
)
330 stream_assert_class(stream
, &ssl_stream_class
);
331 return CONTAINER_OF(stream
, struct ssl_stream
, stream
);
334 /* Extracts and returns the server name from 'suffix'. The caller must
335 * eventually free it.
337 * Returns NULL if there is no server name, and particularly if it is an IP
338 * address rather than a host name, since RFC 3546 is explicit that IP
339 * addresses are unsuitable as server name indication (SNI). */
341 get_server_name(const char *suffix_
)
343 char *suffix
= xstrdup(suffix_
);
346 inet_parse_host_port_tokens(suffix
, &host
, &port
);
349 struct in6_addr ipv6
;
350 char *server_name
= (ip_parse(host
, &ipv4
) || ipv6_parse(host
, &ipv6
)
351 ? NULL
: xstrdup(host
));
359 ssl_open(const char *name
, char *suffix
, struct stream
**streamp
, uint8_t dscp
)
368 error
= inet_open_active(SOCK_STREAM
, suffix
, OFP_PORT
, NULL
, &fd
,
371 int state
= error
? STATE_TCP_CONNECTING
: STATE_SSL_CONNECTING
;
372 return new_ssl_stream(xstrdup(name
), get_server_name(suffix
),
373 fd
, CLIENT
, state
, streamp
);
375 VLOG_ERR("%s: connect: %s", name
, ovs_strerror(error
));
381 do_ca_cert_bootstrap(struct stream
*stream
)
383 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
384 STACK_OF(X509
) *chain
;
390 chain
= SSL_get_peer_cert_chain(sslv
->ssl
);
391 if (!chain
|| !sk_X509_num(chain
)) {
392 VLOG_ERR("could not bootstrap CA cert: no certificate presented by "
396 cert
= sk_X509_value(chain
, sk_X509_num(chain
) - 1);
398 /* Check that 'cert' is self-signed. Otherwise it is not a CA
399 * certificate and we should not attempt to use it as one. */
400 error
= X509_check_issued(cert
, cert
);
402 VLOG_ERR("could not bootstrap CA cert: obtained certificate is "
403 "not self-signed (%s)",
404 X509_verify_cert_error_string(error
));
405 if (sk_X509_num(chain
) < 2) {
406 VLOG_ERR("only one certificate was received, so probably the peer "
407 "is not configured to send its CA certificate");
412 fd
= open(ca_cert
.file_name
, O_CREAT
| O_EXCL
| O_WRONLY
, 0444);
414 if (errno
== EEXIST
) {
415 VLOG_INFO_RL(&rl
, "reading CA cert %s created by another process",
417 stream_ssl_set_ca_cert_file__(ca_cert
.file_name
, true, true);
420 VLOG_ERR("could not bootstrap CA cert: creating %s failed: %s",
421 ca_cert
.file_name
, ovs_strerror(errno
));
426 file
= fdopen(fd
, "w");
429 VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s",
430 ovs_strerror(error
));
431 unlink(ca_cert
.file_name
);
435 if (!PEM_write_X509(file
, cert
)) {
436 VLOG_ERR("could not bootstrap CA cert: PEM_write_X509 to %s failed: "
437 "%s", ca_cert
.file_name
,
438 ERR_error_string(ERR_get_error(), NULL
));
440 unlink(ca_cert
.file_name
);
446 VLOG_ERR("could not bootstrap CA cert: writing %s failed: %s",
447 ca_cert
.file_name
, ovs_strerror(error
));
448 unlink(ca_cert
.file_name
);
452 VLOG_INFO("successfully bootstrapped CA cert to %s", ca_cert
.file_name
);
453 log_ca_cert(ca_cert
.file_name
, cert
);
454 bootstrap_ca_cert
= false;
457 /* SSL_CTX_add_client_CA makes a copy of cert's relevant data. */
458 SSL_CTX_add_client_CA(ctx
, cert
);
460 SSL_CTX_set_cert_store(ctx
, X509_STORE_new());
461 if (SSL_CTX_load_verify_locations(ctx
, ca_cert
.file_name
, NULL
) != 1) {
462 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
463 ERR_error_string(ERR_get_error(), NULL
));
466 VLOG_INFO("killing successful connection to retry using CA cert");
471 get_peer_common_name(const struct ssl_stream
*sslv
)
473 char *peer_name
= NULL
;
474 X509
*peer_cert
= SSL_get_peer_certificate(sslv
->ssl
);
479 int cn_index
= X509_NAME_get_index_by_NID(X509_get_subject_name(peer_cert
),
485 X509_NAME_ENTRY
*cn_entry
= X509_NAME_get_entry(
486 X509_get_subject_name(peer_cert
), cn_index
);
491 ASN1_STRING
*cn_data
= X509_NAME_ENTRY_get_data(cn_entry
);
497 #if OPENSSL_VERSION_NUMBER < 0x10100000L || defined (LIBRESSL_VERSION_NUMBER)
498 /* ASN1_STRING_data() is deprecated as of OpenSSL version 1.1 */
499 cn
= (const char *)ASN1_STRING_data(cn_data
);
501 cn
= (const char *)ASN1_STRING_get0_data(cn_data
);
503 peer_name
= xstrdup(cn
);
506 X509_free(peer_cert
);
511 ssl_connect(struct stream
*stream
)
513 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
516 switch (sslv
->state
) {
517 case STATE_TCP_CONNECTING
:
518 retval
= check_connection_completion(sslv
->fd
);
522 sslv
->state
= STATE_SSL_CONNECTING
;
523 setsockopt_tcp_nodelay(sslv
->fd
);
526 case STATE_SSL_CONNECTING
:
527 /* Capture the first few bytes of received data so that we can guess
528 * what kind of funny data we've been sent if SSL negotiation fails. */
529 if (sslv
->n_head
<= 0) {
530 sslv
->n_head
= recv(sslv
->fd
, sslv
->head
, sizeof sslv
->head
,
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 interpret_ssl_error((sslv
->type
== CLIENT
? "SSL_connect"
544 : "SSL_accept"), retval
, error
, &unused
);
545 shutdown(sslv
->fd
, SHUT_RDWR
);
546 stream_report_content(sslv
->head
, sslv
->n_head
, STREAM_SSL
,
547 &this_module
, stream_get_name(stream
));
550 } else if (bootstrap_ca_cert
) {
551 return do_ca_cert_bootstrap(stream
);
552 } else if (verify_peer_cert
553 && ((SSL_get_verify_mode(sslv
->ssl
)
554 & (SSL_VERIFY_NONE
| SSL_VERIFY_PEER
))
555 != SSL_VERIFY_PEER
)) {
556 /* Two or more SSL connections completed at the same time while we
557 * were in bootstrap mode. Only one of these can finish the
558 * bootstrap successfully. The other one(s) must be rejected
559 * because they were not verified against the bootstrapped CA
560 * certificate. (Alternatively we could verify them against the CA
561 * certificate, but that's more trouble than it's worth. These
562 * connections will succeed the next time they retry, assuming that
563 * they have a certificate against the correct CA.) */
564 VLOG_INFO("rejecting SSL connection during bootstrap race window");
567 #if OPENSSL_SUPPORTS_SNI
568 const char *servername
= SSL_get_servername(
569 sslv
->ssl
, TLSEXT_NAMETYPE_host_name
);
571 VLOG_DBG("connection indicated server name %s", servername
);
575 char *cn
= get_peer_common_name(sslv
);
578 stream_set_peer_id(stream
, cn
);
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. */
607 closesocket(sslv
->fd
);
612 interpret_queued_ssl_error(const char *function
)
614 int queued_error
= ERR_get_error();
615 if (queued_error
!= 0) {
616 VLOG_WARN_RL(&rl
, "%s: %s",
617 function
, ERR_error_string(queued_error
, NULL
));
619 VLOG_ERR_RL(&rl
, "%s: SSL_ERROR_SSL without queued error", function
);
624 interpret_ssl_error(const char *function
, int ret
, int error
,
631 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_NONE", function
);
634 case SSL_ERROR_ZERO_RETURN
:
635 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_ZERO_RETURN", function
);
638 case SSL_ERROR_WANT_READ
:
642 case SSL_ERROR_WANT_WRITE
:
646 case SSL_ERROR_WANT_CONNECT
:
647 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_WANT_CONNECT", function
);
650 case SSL_ERROR_WANT_ACCEPT
:
651 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_WANT_ACCEPT", function
);
654 case SSL_ERROR_WANT_X509_LOOKUP
:
655 VLOG_ERR_RL(&rl
, "%s: unexpected SSL_ERROR_WANT_X509_LOOKUP",
659 case SSL_ERROR_SYSCALL
: {
660 int queued_error
= ERR_get_error();
661 if (queued_error
== 0) {
664 VLOG_WARN_RL(&rl
, "%s: system error (%s)",
665 function
, ovs_strerror(status
));
668 VLOG_WARN_RL(&rl
, "%s: unexpected SSL connection close",
673 VLOG_WARN_RL(&rl
, "%s: %s",
674 function
, ERR_error_string(queued_error
, NULL
));
680 interpret_queued_ssl_error(function
);
684 VLOG_ERR_RL(&rl
, "%s: bad SSL error code %d", function
, error
);
691 ssl_recv(struct stream
*stream
, void *buffer
, size_t n
)
693 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
697 /* Behavior of zero-byte SSL_read is poorly defined. */
700 old_state
= SSL_get_state(sslv
->ssl
);
701 ret
= SSL_read(sslv
->ssl
, buffer
, n
);
702 if (old_state
!= SSL_get_state(sslv
->ssl
)) {
703 sslv
->tx_want
= SSL_NOTHING
;
705 sslv
->rx_want
= SSL_NOTHING
;
710 int error
= SSL_get_error(sslv
->ssl
, ret
);
711 if (error
== SSL_ERROR_ZERO_RETURN
) {
714 return -interpret_ssl_error("SSL_read", ret
, error
,
721 ssl_clear_txbuf(struct ssl_stream
*sslv
)
723 ofpbuf_delete(sslv
->txbuf
);
728 ssl_do_tx(struct stream
*stream
)
730 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
733 int old_state
= SSL_get_state(sslv
->ssl
);
734 int ret
= SSL_write(sslv
->ssl
, sslv
->txbuf
->data
, sslv
->txbuf
->size
);
735 if (old_state
!= SSL_get_state(sslv
->ssl
)) {
736 sslv
->rx_want
= SSL_NOTHING
;
738 sslv
->tx_want
= SSL_NOTHING
;
740 ofpbuf_pull(sslv
->txbuf
, ret
);
741 if (sslv
->txbuf
->size
== 0) {
745 int ssl_error
= SSL_get_error(sslv
->ssl
, ret
);
746 if (ssl_error
== SSL_ERROR_ZERO_RETURN
) {
747 VLOG_WARN_RL(&rl
, "SSL_write: connection closed");
750 return interpret_ssl_error("SSL_write", ret
, ssl_error
,
758 ssl_send(struct stream
*stream
, const void *buffer
, size_t n
)
760 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
767 sslv
->txbuf
= ofpbuf_clone_data(buffer
, n
);
768 error
= ssl_do_tx(stream
);
771 ssl_clear_txbuf(sslv
);
776 ssl_clear_txbuf(sslv
);
783 ssl_run(struct stream
*stream
)
785 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
787 if (sslv
->txbuf
&& ssl_do_tx(stream
) != EAGAIN
) {
788 ssl_clear_txbuf(sslv
);
793 ssl_run_wait(struct stream
*stream
)
795 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
797 if (sslv
->tx_want
!= SSL_NOTHING
) {
798 poll_fd_wait(sslv
->fd
, want_to_poll_events(sslv
->tx_want
));
803 ssl_wait(struct stream
*stream
, enum stream_wait_type wait
)
805 struct ssl_stream
*sslv
= ssl_stream_cast(stream
);
809 if (stream_connect(stream
) != EAGAIN
) {
810 poll_immediate_wake();
812 switch (sslv
->state
) {
813 case STATE_TCP_CONNECTING
:
814 poll_fd_wait(sslv
->fd
, POLLOUT
);
817 case STATE_SSL_CONNECTING
:
818 /* ssl_connect() called SSL_accept() or SSL_connect(), which
819 * set up the status that we test here. */
820 poll_fd_wait(sslv
->fd
,
821 want_to_poll_events(SSL_want(sslv
->ssl
)));
831 if (sslv
->rx_want
!= SSL_NOTHING
) {
832 poll_fd_wait(sslv
->fd
, want_to_poll_events(sslv
->rx_want
));
834 poll_immediate_wake();
840 /* We have room in our tx queue. */
841 poll_immediate_wake();
843 /* stream_run_wait() will do the right thing; don't bother with
853 const struct stream_class ssl_stream_class
= {
855 true, /* needs_probes */
857 ssl_close
, /* close */
858 ssl_connect
, /* connect */
862 ssl_run_wait
, /* run_wait */
870 struct pstream pstream
;
874 const struct pstream_class pssl_pstream_class
;
876 static struct pssl_pstream
*
877 pssl_pstream_cast(struct pstream
*pstream
)
879 pstream_assert_class(pstream
, &pssl_pstream_class
);
880 return CONTAINER_OF(pstream
, struct pssl_pstream
, pstream
);
884 pssl_open(const char *name OVS_UNUSED
, char *suffix
, struct pstream
**pstreamp
,
887 struct sockaddr_storage ss
;
888 struct pssl_pstream
*pssl
;
898 fd
= inet_open_passive(SOCK_STREAM
, suffix
, OFP_PORT
, &ss
, dscp
, true);
903 port
= ss_get_port(&ss
);
905 struct ds bound_name
= DS_EMPTY_INITIALIZER
;
906 ds_put_format(&bound_name
, "pssl:%"PRIu16
":", port
);
907 ss_format_address(&ss
, &bound_name
);
909 pssl
= xmalloc(sizeof *pssl
);
910 pstream_init(&pssl
->pstream
, &pssl_pstream_class
,
911 ds_steal_cstr(&bound_name
));
912 pstream_set_bound_port(&pssl
->pstream
, htons(port
));
914 *pstreamp
= &pssl
->pstream
;
920 pssl_close(struct pstream
*pstream
)
922 struct pssl_pstream
*pssl
= pssl_pstream_cast(pstream
);
923 closesocket(pssl
->fd
);
928 pssl_accept(struct pstream
*pstream
, struct stream
**new_streamp
)
930 struct pssl_pstream
*pssl
= pssl_pstream_cast(pstream
);
931 struct sockaddr_storage ss
;
932 socklen_t ss_len
= sizeof ss
;
936 new_fd
= accept(pssl
->fd
, (struct sockaddr
*) &ss
, &ss_len
);
938 error
= sock_errno();
940 if (error
== WSAEWOULDBLOCK
) {
944 if (error
!= EAGAIN
) {
945 VLOG_DBG_RL(&rl
, "accept: %s", sock_strerror(error
));
950 error
= set_nonblocking(new_fd
);
956 struct ds name
= DS_EMPTY_INITIALIZER
;
957 ds_put_cstr(&name
, "ssl:");
958 ss_format_address(&ss
, &name
);
959 ds_put_format(&name
, ":%"PRIu16
, ss_get_port(&ss
));
960 return new_ssl_stream(ds_steal_cstr(&name
), NULL
, new_fd
, SERVER
,
961 STATE_SSL_CONNECTING
, new_streamp
);
965 pssl_wait(struct pstream
*pstream
)
967 struct pssl_pstream
*pssl
= pssl_pstream_cast(pstream
);
968 poll_fd_wait(pssl
->fd
, POLLIN
);
971 const struct pstream_class pssl_pstream_class
= {
981 * Returns true if OpenSSL error is WANT_READ or WANT_WRITE, indicating that
982 * OpenSSL is requesting that we call it back when the socket is ready for read
983 * or writing, respectively.
986 ssl_wants_io(int ssl_error
)
988 return (ssl_error
== SSL_ERROR_WANT_WRITE
989 || ssl_error
== SSL_ERROR_WANT_READ
);
995 static int init_status
= -1;
996 if (init_status
< 0) {
997 init_status
= do_ssl_init();
998 ovs_assert(init_status
>= 0);
1008 #if OPENSSL_VERSION_NUMBER < 0x10100000L || defined (LIBRESSL_VERSION_NUMBER)
1010 /* The following call is needed if we "#include <openssl/applink.c>". */
1011 CRYPTO_malloc_init();
1014 SSL_load_error_strings();
1017 if (!RAND_status()) {
1018 /* We occasionally see OpenSSL fail to seed its random number generator
1019 * in heavily loaded hypervisors. I suspect the following scenario:
1021 * 1. OpenSSL calls read() to get 32 bytes from /dev/urandom.
1022 * 2. The kernel generates 10 bytes of randomness and copies it out.
1023 * 3. A signal arrives (perhaps SIGALRM).
1024 * 4. The kernel interrupts the system call to service the signal.
1025 * 5. Userspace gets 10 bytes of entropy.
1026 * 6. OpenSSL doesn't read again to get the final 22 bytes. Therefore
1027 * OpenSSL doesn't have enough entropy to consider itself
1030 * The only part I'm not entirely sure about is #6, because the OpenSSL
1031 * code is so hard to read. */
1035 VLOG_WARN("OpenSSL random seeding failed, reseeding ourselves");
1037 retval
= get_entropy(seed
, sizeof seed
);
1039 VLOG_ERR("failed to obtain entropy (%s)",
1040 ovs_retval_to_string(retval
));
1041 return retval
> 0 ? retval
: ENOPROTOOPT
;
1044 RAND_seed(seed
, sizeof seed
);
1047 /* OpenSSL has a bunch of "connection methods": SSLv2_method(),
1048 * SSLv3_method(), TLSv1_method(), SSLv23_method(), ... Most of these
1049 * support exactly one version of SSL, e.g. TLSv1_method() supports TLSv1
1050 * only, not any earlier *or later* version. The only exception is
1051 * SSLv23_method(), which in fact supports *any* version of SSL and TLS.
1052 * We don't want SSLv2 or SSLv3 support, so we turn it off below with
1053 * SSL_CTX_set_options().
1055 * The cast is needed to avoid a warning with newer versions of OpenSSL in
1056 * which SSLv23_method() returns a "const" pointer. */
1057 method
= CONST_CAST(SSL_METHOD
*, SSLv23_method());
1058 if (method
== NULL
) {
1059 VLOG_ERR("TLSv1_method: %s", ERR_error_string(ERR_get_error(), NULL
));
1063 ctx
= SSL_CTX_new(method
);
1065 VLOG_ERR("SSL_CTX_new: %s", ERR_error_string(ERR_get_error(), NULL
));
1068 SSL_CTX_set_options(ctx
, SSL_OP_NO_SSLv2
| SSL_OP_NO_SSLv3
);
1069 SSL_CTX_set_tmp_dh_callback(ctx
, tmp_dh_callback
);
1070 SSL_CTX_set_mode(ctx
, SSL_MODE_ENABLE_PARTIAL_WRITE
);
1071 SSL_CTX_set_mode(ctx
, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER
);
1072 SSL_CTX_set_verify(ctx
, SSL_VERIFY_PEER
| SSL_VERIFY_FAIL_IF_NO_PEER_CERT
,
1074 SSL_CTX_set_session_cache_mode(ctx
, SSL_SESS_CACHE_OFF
);
1075 SSL_CTX_set_cipher_list(ctx
, "HIGH:!aNULL:!MD5");
1081 tmp_dh_callback(SSL
*ssl OVS_UNUSED
, int is_export OVS_UNUSED
, int keylength
)
1086 DH
*(*constructor
)(void);
1089 static struct dh dh_table
[] = {
1090 {1024, NULL
, get_dh1024
},
1091 {2048, NULL
, get_dh2048
},
1092 {4096, NULL
, get_dh4096
},
1097 for (dh
= dh_table
; dh
< &dh_table
[ARRAY_SIZE(dh_table
)]; dh
++) {
1098 if (dh
->keylength
== keylength
) {
1100 dh
->dh
= dh
->constructor();
1108 VLOG_ERR_RL(&rl
, "no Diffie-Hellman parameters for key length %d",
1113 /* Returns true if SSL is at least partially configured. */
1115 stream_ssl_is_configured(void)
1117 return private_key
.file_name
|| certificate
.file_name
|| ca_cert
.file_name
;
1121 update_ssl_config(struct ssl_config_file
*config
, const char *file_name
)
1123 struct timespec mtime
;
1126 if (ssl_init() || !file_name
) {
1130 /* If the file name hasn't changed and neither has the file contents, stop
1132 error
= get_mtime(file_name
, &mtime
);
1133 if (error
&& error
!= ENOENT
) {
1134 VLOG_ERR_RL(&rl
, "%s: stat failed (%s)",
1135 file_name
, ovs_strerror(error
));
1137 if (config
->file_name
1138 && !strcmp(config
->file_name
, file_name
)
1139 && mtime
.tv_sec
== config
->mtime
.tv_sec
1140 && mtime
.tv_nsec
== config
->mtime
.tv_nsec
) {
1144 /* Update 'config'. */
1145 config
->mtime
= mtime
;
1146 if (file_name
!= config
->file_name
) {
1147 free(config
->file_name
);
1148 config
->file_name
= xstrdup(file_name
);
1154 stream_ssl_set_private_key_file__(const char *file_name
)
1156 if (SSL_CTX_use_PrivateKey_file(ctx
, file_name
, SSL_FILETYPE_PEM
) == 1) {
1157 private_key
.read
= true;
1159 VLOG_ERR("SSL_use_PrivateKey_file: %s",
1160 ERR_error_string(ERR_get_error(), NULL
));
1165 stream_ssl_set_private_key_file(const char *file_name
)
1167 if (update_ssl_config(&private_key
, file_name
)) {
1168 stream_ssl_set_private_key_file__(file_name
);
1173 stream_ssl_set_certificate_file__(const char *file_name
)
1175 if (SSL_CTX_use_certificate_file(ctx
, file_name
, SSL_FILETYPE_PEM
) == 1) {
1176 certificate
.read
= true;
1178 VLOG_ERR("SSL_use_certificate_file: %s",
1179 ERR_error_string(ERR_get_error(), NULL
));
1184 stream_ssl_set_certificate_file(const char *file_name
)
1186 if (update_ssl_config(&certificate
, file_name
)) {
1187 stream_ssl_set_certificate_file__(file_name
);
1191 /* Sets the private key and certificate files in one operation. Use this
1192 * interface, instead of calling stream_ssl_set_private_key_file() and
1193 * stream_ssl_set_certificate_file() individually, in the main loop of a
1194 * long-running program whose key and certificate might change at runtime.
1196 * This is important because of OpenSSL's behavior. If an OpenSSL context
1197 * already has a certificate, and stream_ssl_set_private_key_file() is called
1198 * to install a new private key, OpenSSL will report an error because the new
1199 * private key does not match the old certificate. The other order, of setting
1200 * a new certificate, then setting a new private key, does work.
1202 * If this were the only problem, calling stream_ssl_set_certificate_file()
1203 * before stream_ssl_set_private_key_file() would fix it. But, if the private
1204 * key is changed before the certificate (e.g. someone "scp"s or "mv"s the new
1205 * private key in place before the certificate), then OpenSSL would reject that
1206 * change, and then the change of certificate would succeed, but there would be
1207 * no associated private key (because it had only changed once and therefore
1208 * there was no point in re-reading it).
1210 * This function avoids both problems by, whenever either the certificate or
1211 * the private key file changes, re-reading both of them, in the correct order.
1214 stream_ssl_set_key_and_cert(const char *private_key_file
,
1215 const char *certificate_file
)
1217 if (update_ssl_config(&private_key
, private_key_file
)
1218 && update_ssl_config(&certificate
, certificate_file
)) {
1219 stream_ssl_set_certificate_file__(certificate_file
);
1220 stream_ssl_set_private_key_file__(private_key_file
);
1224 /* Sets SSL ciphers based on string input. Aborts with an error message
1225 * if 'arg' is invalid. */
1227 stream_ssl_set_ciphers(const char *arg
)
1229 if (ssl_init() || !arg
|| !strcmp(ssl_ciphers
, arg
)) {
1232 if (SSL_CTX_set_cipher_list(ctx
,arg
) == 0) {
1233 VLOG_ERR("SSL_CTX_set_cipher_list: %s",
1234 ERR_error_string(ERR_get_error(), NULL
));
1236 ssl_ciphers
= xstrdup(arg
);
1239 /* Set SSL protocols based on the string input. Aborts with an error message
1240 * if 'arg' is invalid. */
1242 stream_ssl_set_protocols(const char *arg
)
1244 if (ssl_init() || !arg
|| !strcmp(arg
, ssl_protocols
)){
1248 /* Start with all the flags off and turn them on as requested. */
1249 #ifndef SSL_OP_NO_SSL_MASK
1250 /* For old OpenSSL without this macro, this is the correct value. */
1251 #define SSL_OP_NO_SSL_MASK (SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | \
1252 SSL_OP_NO_TLSv1 | SSL_OP_NO_TLSv1_1 | \
1255 long protocol_flags
= SSL_OP_NO_SSL_MASK
;
1257 char *s
= xstrdup(arg
);
1258 char *save_ptr
= NULL
;
1259 char *word
= strtok_r(s
, " ,\t", &save_ptr
);
1261 VLOG_ERR("SSL protocol settings invalid");
1264 while (word
!= NULL
) {
1266 if (!strcasecmp(word
, "TLSv1.2")){
1267 on_flag
= SSL_OP_NO_TLSv1_2
;
1268 } else if (!strcasecmp(word
, "TLSv1.1")){
1269 on_flag
= SSL_OP_NO_TLSv1_1
;
1270 } else if (!strcasecmp(word
, "TLSv1")){
1271 on_flag
= SSL_OP_NO_TLSv1
;
1273 VLOG_ERR("%s: SSL protocol not recognized", word
);
1276 /* Reverse the no flag and mask it out in the flags
1277 * to turn on that protocol. */
1278 protocol_flags
&= ~on_flag
;
1279 word
= strtok_r(NULL
, " ,\t", &save_ptr
);
1282 /* Set the actual options. */
1283 SSL_CTX_set_options(ctx
, protocol_flags
);
1285 ssl_protocols
= xstrdup(arg
);
1291 /* Reads the X509 certificate or certificates in file 'file_name'. On success,
1292 * stores the address of the first element in an array of pointers to
1293 * certificates in '*certs' and the number of certificates in the array in
1294 * '*n_certs', and returns 0. On failure, stores a null pointer in '*certs', 0
1295 * in '*n_certs', and returns a positive errno value.
1297 * The caller is responsible for freeing '*certs'. */
1299 read_cert_file(const char *file_name
, X509
***certs
, size_t *n_certs
)
1302 size_t allocated_certs
= 0;
1307 file
= fopen(file_name
, "r");
1309 VLOG_ERR("failed to open %s for reading: %s",
1310 file_name
, ovs_strerror(errno
));
1318 /* Read certificate from file. */
1319 cert
= PEM_read_X509(file
, NULL
, NULL
, NULL
);
1323 VLOG_ERR("PEM_read_X509 failed reading %s: %s",
1324 file_name
, ERR_error_string(ERR_get_error(), NULL
));
1325 for (i
= 0; i
< *n_certs
; i
++) {
1326 X509_free((*certs
)[i
]);
1335 /* Add certificate to array. */
1336 if (*n_certs
>= allocated_certs
) {
1337 *certs
= x2nrealloc(*certs
, &allocated_certs
, sizeof **certs
);
1339 (*certs
)[(*n_certs
)++] = cert
;
1341 /* Are there additional certificates in the file? */
1344 } while (isspace(c
));
1355 /* Sets 'file_name' as the name of a file containing one or more X509
1356 * certificates to send to the peer. Typical use in OpenFlow is to send the CA
1357 * certificate to the peer, which enables a switch to pick up the controller's
1358 * CA certificate on its first connection. */
1360 stream_ssl_set_peer_ca_cert_file(const char *file_name
)
1370 if (!read_cert_file(file_name
, &certs
, &n_certs
)) {
1371 for (i
= 0; i
< n_certs
; i
++) {
1372 if (SSL_CTX_add_extra_chain_cert(ctx
, certs
[i
]) != 1) {
1373 VLOG_ERR("SSL_CTX_add_extra_chain_cert: %s",
1374 ERR_error_string(ERR_get_error(), NULL
));
1381 /* Logs fingerprint of CA certificate 'cert' obtained from 'file_name'. */
1383 log_ca_cert(const char *file_name
, X509
*cert
)
1385 unsigned char digest
[EVP_MAX_MD_SIZE
];
1386 unsigned int n_bytes
;
1391 if (!X509_digest(cert
, EVP_sha1(), digest
, &n_bytes
)) {
1392 ds_put_cstr(&fp
, "<out of memory>");
1395 for (i
= 0; i
< n_bytes
; i
++) {
1397 ds_put_char(&fp
, ':');
1399 ds_put_format(&fp
, "%02x", digest
[i
]);
1402 subject
= X509_NAME_oneline(X509_get_subject_name(cert
), NULL
, 0);
1403 VLOG_INFO("Trusting CA cert from %s (%s) (fingerprint %s)", file_name
,
1404 subject
? subject
: "<out of memory>", ds_cstr(&fp
));
1405 OPENSSL_free(subject
);
1410 stream_ssl_set_ca_cert_file__(const char *file_name
,
1411 bool bootstrap
, bool force
)
1415 if (!update_ssl_config(&ca_cert
, file_name
) && !force
) {
1419 if (!strcmp(file_name
, "none")) {
1420 verify_peer_cert
= false;
1421 VLOG_WARN("Peer certificate validation disabled "
1422 "(this is a security risk)");
1423 } else if (bootstrap
&& stat(file_name
, &s
) && errno
== ENOENT
) {
1424 bootstrap_ca_cert
= true;
1426 STACK_OF(X509_NAME
) *cert_names
= SSL_load_client_CA_file(file_name
);
1428 /* Set up list of CAs that the server will accept from the
1430 SSL_CTX_set_client_CA_list(ctx
, cert_names
);
1432 /* Set up CAs for OpenSSL to trust in verifying the peer's
1434 SSL_CTX_set_cert_store(ctx
, X509_STORE_new());
1435 if (SSL_CTX_load_verify_locations(ctx
, file_name
, NULL
) != 1) {
1436 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
1437 ERR_error_string(ERR_get_error(), NULL
));
1440 bootstrap_ca_cert
= false;
1442 VLOG_ERR("failed to load client certificates from %s: %s",
1443 file_name
, ERR_error_string(ERR_get_error(), NULL
));
1446 ca_cert
.read
= true;
1449 /* Sets 'file_name' as the name of the file from which to read the CA
1450 * certificate used to verify the peer within SSL connections. If 'bootstrap'
1451 * is false, the file must exist. If 'bootstrap' is false, then the file is
1452 * read if it is exists; if it does not, then it will be created from the CA
1453 * certificate received from the peer on the first SSL connection. */
1455 stream_ssl_set_ca_cert_file(const char *file_name
, bool bootstrap
)
1457 stream_ssl_set_ca_cert_file__(file_name
, bootstrap
, false);
1460 /* SSL protocol logging. */
1463 ssl_alert_level_to_string(uint8_t type
)
1466 case 1: return "warning";
1467 case 2: return "fatal";
1468 default: return "<unknown>";
1473 ssl_alert_description_to_string(uint8_t type
)
1476 case 0: return "close_notify";
1477 case 10: return "unexpected_message";
1478 case 20: return "bad_record_mac";
1479 case 21: return "decryption_failed";
1480 case 22: return "record_overflow";
1481 case 30: return "decompression_failure";
1482 case 40: return "handshake_failure";
1483 case 42: return "bad_certificate";
1484 case 43: return "unsupported_certificate";
1485 case 44: return "certificate_revoked";
1486 case 45: return "certificate_expired";
1487 case 46: return "certificate_unknown";
1488 case 47: return "illegal_parameter";
1489 case 48: return "unknown_ca";
1490 case 49: return "access_denied";
1491 case 50: return "decode_error";
1492 case 51: return "decrypt_error";
1493 case 60: return "export_restriction";
1494 case 70: return "protocol_version";
1495 case 71: return "insufficient_security";
1496 case 80: return "internal_error";
1497 case 90: return "user_canceled";
1498 case 100: return "no_renegotiation";
1499 default: return "<unknown>";
1504 ssl_handshake_type_to_string(uint8_t type
)
1507 case 0: return "hello_request";
1508 case 1: return "client_hello";
1509 case 2: return "server_hello";
1510 case 11: return "certificate";
1511 case 12: return "server_key_exchange";
1512 case 13: return "certificate_request";
1513 case 14: return "server_hello_done";
1514 case 15: return "certificate_verify";
1515 case 16: return "client_key_exchange";
1516 case 20: return "finished";
1517 default: return "<unknown>";
1522 ssl_protocol_cb(int write_p
, int version OVS_UNUSED
, int content_type
,
1523 const void *buf_
, size_t len
, SSL
*ssl OVS_UNUSED
, void *sslv_
)
1525 const struct ssl_stream
*sslv
= sslv_
;
1526 const uint8_t *buf
= buf_
;
1529 if (!VLOG_IS_DBG_ENABLED()) {
1534 if (content_type
== 20) {
1535 ds_put_cstr(&details
, "change_cipher_spec");
1536 } else if (content_type
== 21) {
1537 ds_put_format(&details
, "alert: %s, %s",
1538 ssl_alert_level_to_string(buf
[0]),
1539 ssl_alert_description_to_string(buf
[1]));
1540 } else if (content_type
== 22) {
1541 ds_put_format(&details
, "handshake: %s",
1542 ssl_handshake_type_to_string(buf
[0]));
1544 ds_put_format(&details
, "type %d", content_type
);
1547 VLOG_DBG("%s%u%s%s %s (%"PRIuSIZE
" bytes)",
1548 sslv
->type
== CLIENT
? "client" : "server",
1549 sslv
->session_nr
, write_p
? "-->" : "<--",
1550 stream_get_name(&sslv
->stream
), ds_cstr(&details
), len
);
1552 ds_destroy(&details
);