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>
33 #include "dynamic-string.h"
34 #include "leak-checker.h"
36 #include "openflow/openflow.h"
38 #include "poll-loop.h"
39 #include "socket-util.h"
41 #include "stream-provider.h"
46 VLOG_DEFINE_THIS_MODULE(stream_ssl)
64 enum session_type type;
68 unsigned int session_nr;
70 /* rx_want and tx_want record the result of the last call to SSL_read()
71 * and SSL_write(), respectively:
73 * - If the call reported that data needed to be read from the file
74 * descriptor, the corresponding member is set to SSL_READING.
76 * - If the call reported that data needed to be written to the file
77 * descriptor, the corresponding member is set to SSL_WRITING.
79 * - Otherwise, the member is set to SSL_NOTHING, indicating that the
80 * call completed successfully (or with an error) and that there is no
83 * These are needed because there is no way to ask OpenSSL what a data read
84 * or write would require without giving it a buffer to receive into or
85 * data to send, respectively. (Note that the SSL_want() status is
86 * overwritten by each SSL_read() or SSL_write() call, so we can't rely on
89 * A single call to SSL_read() or SSL_write() can perform both reading
90 * and writing and thus invalidate not one of these values but actually
91 * both. Consider this situation, for example:
93 * - SSL_write() blocks on a read, so tx_want gets SSL_READING.
95 * - SSL_read() laters succeeds reading from 'fd' and clears out the
96 * whole receive buffer, so rx_want gets SSL_READING.
98 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
101 * - Now we're stuck blocking until the peer sends us data, even though
102 * SSL_write() could now succeed, which could easily be a deadlock
105 * On the other hand, we can't reset both tx_want and rx_want on every call
106 * to SSL_read() or SSL_write(), because that would produce livelock,
107 * e.g. in this situation:
109 * - SSL_write() blocks, so tx_want gets SSL_READING or SSL_WRITING.
111 * - SSL_read() blocks, so rx_want gets SSL_READING or SSL_WRITING,
112 * but tx_want gets reset to SSL_NOTHING.
114 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
117 * - Client wakes up immediately since SSL_NOTHING in tx_want indicates
118 * that no blocking is necessary.
120 * The solution we adopt here is to set tx_want to SSL_NOTHING after
121 * calling SSL_read() only if the SSL state of the connection changed,
122 * which indicates that an SSL-level renegotiation made some progress, and
123 * similarly for rx_want and SSL_write(). This prevents both the
124 * deadlock and livelock situations above.
126 int rx_want, tx_want;
128 /* A few bytes of header data in case SSL negotiation fails. */
133 /* SSL context created by ssl_init(). */
136 struct ssl_config_file {
137 bool read; /* Whether the file was successfully read. */
138 char *file_name; /* Configured file name, if any. */
139 struct timespec mtime; /* File mtime as of last time we read it. */
142 /* SSL configuration files. */
143 static struct ssl_config_file private_key;
144 static struct ssl_config_file certificate;
145 static struct ssl_config_file ca_cert;
147 /* Ordinarily, the SSL client and server verify each other's certificates using
148 * a CA certificate. Setting this to false disables this behavior. (This is a
150 static bool verify_peer_cert = true;
152 /* Ordinarily, we require a CA certificate for the peer to be locally
153 * available. We can, however, bootstrap the CA certificate from the peer at
154 * the beginning of our first connection then use that certificate on all
155 * subsequent connections, saving it to a file for use in future runs also. In
156 * this case, 'bootstrap_ca_cert' is true. */
157 static bool bootstrap_ca_cert;
159 /* Session number. Used in debug logging messages to uniquely identify a
161 static unsigned int next_session_nr;
163 /* Who knows what can trigger various SSL errors, so let's throttle them down
165 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 25);
167 static int ssl_init(void);
168 static int do_ssl_init(void);
169 static bool ssl_wants_io(int ssl_error);
170 static void ssl_close(struct stream *);
171 static void ssl_clear_txbuf(struct ssl_stream *);
172 static int interpret_ssl_error(const char *function, int ret, int error,
174 static DH *tmp_dh_callback(SSL *ssl, int is_export OVS_UNUSED, int keylength);
175 static void log_ca_cert(const char *file_name, X509 *cert);
176 static void stream_ssl_set_ca_cert_file__(const char *file_name,
178 static void ssl_protocol_cb(int write_p, int version, int content_type,
179 const void *, size_t, SSL *, void *sslv_);
182 want_to_poll_events(int want)
200 new_ssl_stream(const char *name, int fd, enum session_type type,
201 enum ssl_state state, const struct sockaddr_in *remote,
202 struct stream **streamp)
204 struct sockaddr_in local;
205 socklen_t local_len = sizeof local;
206 struct ssl_stream *sslv;
211 /* Check for all the needful configuration. */
213 if (!private_key.read) {
214 VLOG_ERR("Private key must be configured to use SSL");
215 retval = ENOPROTOOPT;
217 if (!certificate.read) {
218 VLOG_ERR("Certificate must be configured to use SSL");
219 retval = ENOPROTOOPT;
221 if (!ca_cert.read && verify_peer_cert && !bootstrap_ca_cert) {
222 VLOG_ERR("CA certificate must be configured to use SSL");
223 retval = ENOPROTOOPT;
225 if (!SSL_CTX_check_private_key(ctx)) {
226 VLOG_ERR("Private key does not match certificate public key: %s",
227 ERR_error_string(ERR_get_error(), NULL));
228 retval = ENOPROTOOPT;
234 /* Get the local IP and port information */
235 retval = getsockname(fd, (struct sockaddr *) &local, &local_len);
237 memset(&local, 0, sizeof local);
241 retval = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof on);
243 VLOG_ERR("%s: setsockopt(TCP_NODELAY): %s", name, strerror(errno));
248 /* Create and configure OpenSSL stream. */
251 VLOG_ERR("SSL_new: %s", ERR_error_string(ERR_get_error(), NULL));
252 retval = ENOPROTOOPT;
255 if (SSL_set_fd(ssl, fd) == 0) {
256 VLOG_ERR("SSL_set_fd: %s", ERR_error_string(ERR_get_error(), NULL));
257 retval = ENOPROTOOPT;
260 if (!verify_peer_cert || (bootstrap_ca_cert && type == CLIENT)) {
261 SSL_set_verify(ssl, SSL_VERIFY_NONE, NULL);
264 /* Create and return the ssl_stream. */
265 sslv = xmalloc(sizeof *sslv);
266 stream_init(&sslv->stream, &ssl_stream_class, EAGAIN, name);
267 stream_set_remote_ip(&sslv->stream, remote->sin_addr.s_addr);
268 stream_set_remote_port(&sslv->stream, remote->sin_port);
269 stream_set_local_ip(&sslv->stream, local.sin_addr.s_addr);
270 stream_set_local_port(&sslv->stream, local.sin_port);
276 sslv->rx_want = sslv->tx_want = SSL_NOTHING;
277 sslv->session_nr = next_session_nr++;
280 if (VLOG_IS_DBG_ENABLED()) {
281 SSL_set_msg_callback(ssl, ssl_protocol_cb);
282 SSL_set_msg_callback_arg(ssl, sslv);
285 *streamp = &sslv->stream;
296 static struct ssl_stream *
297 ssl_stream_cast(struct stream *stream)
299 stream_assert_class(stream, &ssl_stream_class);
300 return CONTAINER_OF(stream, struct ssl_stream, stream);
304 ssl_open(const char *name, char *suffix, struct stream **streamp)
306 struct sockaddr_in sin;
314 error = inet_open_active(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin, &fd);
316 int state = error ? STATE_TCP_CONNECTING : STATE_SSL_CONNECTING;
317 return new_ssl_stream(name, fd, CLIENT, state, &sin, streamp);
319 VLOG_ERR("%s: connect: %s", name, strerror(error));
325 do_ca_cert_bootstrap(struct stream *stream)
327 struct ssl_stream *sslv = ssl_stream_cast(stream);
328 STACK_OF(X509) *chain;
334 chain = SSL_get_peer_cert_chain(sslv->ssl);
335 if (!chain || !sk_X509_num(chain)) {
336 VLOG_ERR("could not bootstrap CA cert: no certificate presented by "
340 cert = sk_X509_value(chain, sk_X509_num(chain) - 1);
342 /* Check that 'cert' is self-signed. Otherwise it is not a CA
343 * certificate and we should not attempt to use it as one. */
344 error = X509_check_issued(cert, cert);
346 VLOG_ERR("could not bootstrap CA cert: obtained certificate is "
347 "not self-signed (%s)",
348 X509_verify_cert_error_string(error));
349 if (sk_X509_num(chain) < 2) {
350 VLOG_ERR("only one certificate was received, so probably the peer "
351 "is not configured to send its CA certificate");
356 fd = open(ca_cert.file_name, O_CREAT | O_EXCL | O_WRONLY, 0444);
358 if (errno == EEXIST) {
359 VLOG_INFO("reading CA cert %s created by another process",
361 stream_ssl_set_ca_cert_file(ca_cert.file_name, true);
364 VLOG_ERR("could not bootstrap CA cert: creating %s failed: %s",
365 ca_cert.file_name, strerror(errno));
370 file = fdopen(fd, "w");
373 VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s",
375 unlink(ca_cert.file_name);
379 if (!PEM_write_X509(file, cert)) {
380 VLOG_ERR("could not bootstrap CA cert: PEM_write_X509 to %s failed: "
381 "%s", ca_cert.file_name,
382 ERR_error_string(ERR_get_error(), NULL));
384 unlink(ca_cert.file_name);
390 VLOG_ERR("could not bootstrap CA cert: writing %s failed: %s",
391 ca_cert.file_name, strerror(error));
392 unlink(ca_cert.file_name);
396 VLOG_INFO("successfully bootstrapped CA cert to %s", ca_cert.file_name);
397 log_ca_cert(ca_cert.file_name, cert);
398 bootstrap_ca_cert = false;
401 /* SSL_CTX_add_client_CA makes a copy of cert's relevant data. */
402 SSL_CTX_add_client_CA(ctx, cert);
404 /* SSL_CTX_use_certificate() takes ownership of the certificate passed in.
405 * 'cert' is owned by sslv->ssl, so we need to duplicate it. */
406 cert = X509_dup(cert);
410 if (SSL_CTX_load_verify_locations(ctx, ca_cert.file_name, NULL) != 1) {
411 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
412 ERR_error_string(ERR_get_error(), NULL));
415 VLOG_INFO("killing successful connection to retry using CA cert");
420 ssl_connect(struct stream *stream)
422 struct ssl_stream *sslv = ssl_stream_cast(stream);
425 switch (sslv->state) {
426 case STATE_TCP_CONNECTING:
427 retval = check_connection_completion(sslv->fd);
431 sslv->state = STATE_SSL_CONNECTING;
434 case STATE_SSL_CONNECTING:
435 /* Capture the first few bytes of received data so that we can guess
436 * what kind of funny data we've been sent if SSL negotation fails. */
437 if (sslv->n_head <= 0) {
438 sslv->n_head = recv(sslv->fd, sslv->head, sizeof sslv->head,
442 retval = (sslv->type == CLIENT
443 ? SSL_connect(sslv->ssl) : SSL_accept(sslv->ssl));
445 int error = SSL_get_error(sslv->ssl, retval);
446 if (retval < 0 && ssl_wants_io(error)) {
450 interpret_ssl_error((sslv->type == CLIENT ? "SSL_connect"
451 : "SSL_accept"), retval, error, &unused);
452 shutdown(sslv->fd, SHUT_RDWR);
453 stream_report_content(sslv->head, sslv->n_head, STREAM_SSL,
454 THIS_MODULE, stream_get_name(stream));
457 } else if (bootstrap_ca_cert) {
458 return do_ca_cert_bootstrap(stream);
459 } else if (verify_peer_cert
460 && ((SSL_get_verify_mode(sslv->ssl)
461 & (SSL_VERIFY_NONE | SSL_VERIFY_PEER))
462 != SSL_VERIFY_PEER)) {
463 /* Two or more SSL connections completed at the same time while we
464 * were in bootstrap mode. Only one of these can finish the
465 * bootstrap successfully. The other one(s) must be rejected
466 * because they were not verified against the bootstrapped CA
467 * certificate. (Alternatively we could verify them against the CA
468 * certificate, but that's more trouble than it's worth. These
469 * connections will succeed the next time they retry, assuming that
470 * they have a certificate against the correct CA.) */
471 VLOG_ERR("rejecting SSL connection during bootstrap race window");
482 ssl_close(struct stream *stream)
484 struct ssl_stream *sslv = ssl_stream_cast(stream);
485 ssl_clear_txbuf(sslv);
487 /* Attempt clean shutdown of the SSL connection. This will work most of
488 * the time, as long as the kernel send buffer has some free space and the
489 * SSL connection isn't renegotiating, etc. That has to be good enough,
490 * since we don't have any way to continue the close operation in the
492 SSL_shutdown(sslv->ssl);
494 /* SSL_shutdown() might have signaled an error, in which case we need to
495 * flush it out of the OpenSSL error queue or the next OpenSSL operation
496 * will falsely signal an error. */
505 interpret_ssl_error(const char *function, int ret, int error,
512 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_NONE", function);
515 case SSL_ERROR_ZERO_RETURN:
516 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_ZERO_RETURN", function);
519 case SSL_ERROR_WANT_READ:
523 case SSL_ERROR_WANT_WRITE:
527 case SSL_ERROR_WANT_CONNECT:
528 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_CONNECT", function);
531 case SSL_ERROR_WANT_ACCEPT:
532 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_ACCEPT", function);
535 case SSL_ERROR_WANT_X509_LOOKUP:
536 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_X509_LOOKUP",
540 case SSL_ERROR_SYSCALL: {
541 int queued_error = ERR_get_error();
542 if (queued_error == 0) {
545 VLOG_WARN_RL(&rl, "%s: system error (%s)",
546 function, strerror(status));
549 VLOG_WARN_RL(&rl, "%s: unexpected SSL connection close",
554 VLOG_WARN_RL(&rl, "%s: %s",
555 function, ERR_error_string(queued_error, NULL));
560 case SSL_ERROR_SSL: {
561 int queued_error = ERR_get_error();
562 if (queued_error != 0) {
563 VLOG_WARN_RL(&rl, "%s: %s",
564 function, ERR_error_string(queued_error, NULL));
566 VLOG_ERR_RL(&rl, "%s: SSL_ERROR_SSL without queued error",
573 VLOG_ERR_RL(&rl, "%s: bad SSL error code %d", function, error);
580 ssl_recv(struct stream *stream, void *buffer, size_t n)
582 struct ssl_stream *sslv = ssl_stream_cast(stream);
586 /* Behavior of zero-byte SSL_read is poorly defined. */
589 old_state = SSL_get_state(sslv->ssl);
590 ret = SSL_read(sslv->ssl, buffer, n);
591 if (old_state != SSL_get_state(sslv->ssl)) {
592 sslv->tx_want = SSL_NOTHING;
594 sslv->rx_want = SSL_NOTHING;
599 int error = SSL_get_error(sslv->ssl, ret);
600 if (error == SSL_ERROR_ZERO_RETURN) {
603 return -interpret_ssl_error("SSL_read", ret, error,
610 ssl_clear_txbuf(struct ssl_stream *sslv)
612 ofpbuf_delete(sslv->txbuf);
617 ssl_do_tx(struct stream *stream)
619 struct ssl_stream *sslv = ssl_stream_cast(stream);
622 int old_state = SSL_get_state(sslv->ssl);
623 int ret = SSL_write(sslv->ssl, sslv->txbuf->data, sslv->txbuf->size);
624 if (old_state != SSL_get_state(sslv->ssl)) {
625 sslv->rx_want = SSL_NOTHING;
627 sslv->tx_want = SSL_NOTHING;
629 ofpbuf_pull(sslv->txbuf, ret);
630 if (sslv->txbuf->size == 0) {
634 int ssl_error = SSL_get_error(sslv->ssl, ret);
635 if (ssl_error == SSL_ERROR_ZERO_RETURN) {
636 VLOG_WARN_RL(&rl, "SSL_write: connection closed");
639 return interpret_ssl_error("SSL_write", ret, ssl_error,
647 ssl_send(struct stream *stream, const void *buffer, size_t n)
649 struct ssl_stream *sslv = ssl_stream_cast(stream);
656 sslv->txbuf = ofpbuf_clone_data(buffer, n);
657 error = ssl_do_tx(stream);
660 ssl_clear_txbuf(sslv);
663 leak_checker_claim(buffer);
673 ssl_run(struct stream *stream)
675 struct ssl_stream *sslv = ssl_stream_cast(stream);
677 if (sslv->txbuf && ssl_do_tx(stream) != EAGAIN) {
678 ssl_clear_txbuf(sslv);
683 ssl_run_wait(struct stream *stream)
685 struct ssl_stream *sslv = ssl_stream_cast(stream);
687 if (sslv->tx_want != SSL_NOTHING) {
688 poll_fd_wait(sslv->fd, want_to_poll_events(sslv->tx_want));
693 ssl_wait(struct stream *stream, enum stream_wait_type wait)
695 struct ssl_stream *sslv = ssl_stream_cast(stream);
699 if (stream_connect(stream) != EAGAIN) {
700 poll_immediate_wake();
702 switch (sslv->state) {
703 case STATE_TCP_CONNECTING:
704 poll_fd_wait(sslv->fd, POLLOUT);
707 case STATE_SSL_CONNECTING:
708 /* ssl_connect() called SSL_accept() or SSL_connect(), which
709 * set up the status that we test here. */
710 poll_fd_wait(sslv->fd,
711 want_to_poll_events(SSL_want(sslv->ssl)));
721 if (sslv->rx_want != SSL_NOTHING) {
722 poll_fd_wait(sslv->fd, want_to_poll_events(sslv->rx_want));
724 poll_immediate_wake();
730 /* We have room in our tx queue. */
731 poll_immediate_wake();
733 /* stream_run_wait() will do the right thing; don't bother with
743 struct stream_class ssl_stream_class = {
746 ssl_close, /* close */
747 ssl_connect, /* connect */
751 ssl_run_wait, /* run_wait */
759 struct pstream pstream;
763 struct pstream_class pssl_pstream_class;
765 static struct pssl_pstream *
766 pssl_pstream_cast(struct pstream *pstream)
768 pstream_assert_class(pstream, &pssl_pstream_class);
769 return CONTAINER_OF(pstream, struct pssl_pstream, pstream);
773 pssl_open(const char *name OVS_UNUSED, char *suffix, struct pstream **pstreamp)
775 struct pssl_pstream *pssl;
776 struct sockaddr_in sin;
777 char bound_name[128];
786 fd = inet_open_passive(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin);
790 sprintf(bound_name, "pssl:%"PRIu16":"IP_FMT,
791 ntohs(sin.sin_port), IP_ARGS(&sin.sin_addr.s_addr));
793 pssl = xmalloc(sizeof *pssl);
794 pstream_init(&pssl->pstream, &pssl_pstream_class, bound_name);
796 *pstreamp = &pssl->pstream;
801 pssl_close(struct pstream *pstream)
803 struct pssl_pstream *pssl = pssl_pstream_cast(pstream);
809 pssl_accept(struct pstream *pstream, struct stream **new_streamp)
811 struct pssl_pstream *pssl = pssl_pstream_cast(pstream);
812 struct sockaddr_in sin;
813 socklen_t sin_len = sizeof sin;
818 new_fd = accept(pssl->fd, &sin, &sin_len);
821 if (error != EAGAIN) {
822 VLOG_DBG_RL(&rl, "accept: %s", strerror(error));
827 error = set_nonblocking(new_fd);
833 sprintf(name, "ssl:"IP_FMT, IP_ARGS(&sin.sin_addr));
834 if (sin.sin_port != htons(OFP_SSL_PORT)) {
835 sprintf(strchr(name, '\0'), ":%"PRIu16, ntohs(sin.sin_port));
837 return new_ssl_stream(name, new_fd, SERVER, STATE_SSL_CONNECTING, &sin,
842 pssl_wait(struct pstream *pstream)
844 struct pssl_pstream *pssl = pssl_pstream_cast(pstream);
845 poll_fd_wait(pssl->fd, POLLIN);
848 struct pstream_class pssl_pstream_class = {
857 * Returns true if OpenSSL error is WANT_READ or WANT_WRITE, indicating that
858 * OpenSSL is requesting that we call it back when the socket is ready for read
859 * or writing, respectively.
862 ssl_wants_io(int ssl_error)
864 return (ssl_error == SSL_ERROR_WANT_WRITE
865 || ssl_error == SSL_ERROR_WANT_READ);
871 static int init_status = -1;
872 if (init_status < 0) {
873 init_status = do_ssl_init();
874 assert(init_status >= 0);
885 SSL_load_error_strings();
887 method = TLSv1_method();
888 if (method == NULL) {
889 VLOG_ERR("TLSv1_method: %s", ERR_error_string(ERR_get_error(), NULL));
893 ctx = SSL_CTX_new(method);
895 VLOG_ERR("SSL_CTX_new: %s", ERR_error_string(ERR_get_error(), NULL));
898 SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
899 SSL_CTX_set_tmp_dh_callback(ctx, tmp_dh_callback);
900 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
901 SSL_CTX_set_mode(ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
902 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
909 tmp_dh_callback(SSL *ssl OVS_UNUSED, int is_export OVS_UNUSED, int keylength)
914 DH *(*constructor)(void);
917 static struct dh dh_table[] = {
918 {1024, NULL, get_dh1024},
919 {2048, NULL, get_dh2048},
920 {4096, NULL, get_dh4096},
925 for (dh = dh_table; dh < &dh_table[ARRAY_SIZE(dh_table)]; dh++) {
926 if (dh->keylength == keylength) {
928 dh->dh = dh->constructor();
930 ovs_fatal(ENOMEM, "out of memory constructing "
931 "Diffie-Hellman parameters");
937 VLOG_ERR_RL(&rl, "no Diffie-Hellman parameters for key length %d",
942 /* Returns true if SSL is at least partially configured. */
944 stream_ssl_is_configured(void)
946 return private_key.file_name || certificate.file_name || ca_cert.file_name;
950 update_ssl_config(struct ssl_config_file *config, const char *file_name)
952 struct timespec mtime;
954 if (ssl_init() || !file_name) {
958 /* If the file name hasn't changed and neither has the file contents, stop
960 get_mtime(file_name, &mtime);
961 if (config->file_name
962 && !strcmp(config->file_name, file_name)
963 && mtime.tv_sec == config->mtime.tv_sec
964 && mtime.tv_nsec == config->mtime.tv_nsec) {
968 /* Update 'config'. */
969 config->mtime = mtime;
970 if (file_name != config->file_name) {
971 free(config->file_name);
972 config->file_name = xstrdup(file_name);
978 stream_ssl_set_private_key_file__(const char *file_name)
980 if (SSL_CTX_use_PrivateKey_file(ctx, file_name, SSL_FILETYPE_PEM) == 1) {
981 private_key.read = true;
983 VLOG_ERR("SSL_use_PrivateKey_file: %s",
984 ERR_error_string(ERR_get_error(), NULL));
989 stream_ssl_set_private_key_file(const char *file_name)
991 if (update_ssl_config(&private_key, file_name)) {
992 stream_ssl_set_private_key_file__(file_name);
997 stream_ssl_set_certificate_file__(const char *file_name)
999 if (SSL_CTX_use_certificate_chain_file(ctx, file_name) == 1) {
1000 certificate.read = true;
1002 VLOG_ERR("SSL_use_certificate_file: %s",
1003 ERR_error_string(ERR_get_error(), NULL));
1008 stream_ssl_set_certificate_file(const char *file_name)
1010 if (update_ssl_config(&certificate, file_name)) {
1011 stream_ssl_set_certificate_file__(file_name);
1015 /* Sets the private key and certificate files in one operation. Use this
1016 * interface, instead of calling stream_ssl_set_private_key_file() and
1017 * stream_ssl_set_certificate_file() individually, in the main loop of a
1018 * long-running program whose key and certificate might change at runtime.
1020 * This is important because of OpenSSL's behavior. If an OpenSSL context
1021 * already has a certificate, and stream_ssl_set_private_key_file() is called
1022 * to install a new private key, OpenSSL will report an error because the new
1023 * private key does not match the old certificate. The other order, of setting
1024 * a new certificate, then setting a new private key, does work.
1026 * If this were the only problem, calling stream_ssl_set_certificate_file()
1027 * before stream_ssl_set_private_key_file() would fix it. But, if the private
1028 * key is changed before the certificate (e.g. someone "scp"s or "mv"s the new
1029 * private key in place before the certificate), then OpenSSL would reject that
1030 * change, and then the change of certificate would succeed, but there would be
1031 * no associated private key (because it had only changed once and therefore
1032 * there was no point in re-reading it).
1034 * This function avoids both problems by, whenever either the certificate or
1035 * the private key file changes, re-reading both of them, in the correct order.
1038 stream_ssl_set_key_and_cert(const char *private_key_file,
1039 const char *certificate_file)
1041 if (update_ssl_config(&private_key, private_key_file)
1042 || update_ssl_config(&certificate, certificate_file)) {
1043 stream_ssl_set_certificate_file__(certificate_file);
1044 stream_ssl_set_private_key_file__(private_key_file);
1048 /* Reads the X509 certificate or certificates in file 'file_name'. On success,
1049 * stores the address of the first element in an array of pointers to
1050 * certificates in '*certs' and the number of certificates in the array in
1051 * '*n_certs', and returns 0. On failure, stores a null pointer in '*certs', 0
1052 * in '*n_certs', and returns a positive errno value.
1054 * The caller is responsible for freeing '*certs'. */
1056 read_cert_file(const char *file_name, X509 ***certs, size_t *n_certs)
1059 size_t allocated_certs = 0;
1064 file = fopen(file_name, "r");
1066 VLOG_ERR("failed to open %s for reading: %s",
1067 file_name, strerror(errno));
1075 /* Read certificate from file. */
1076 certificate = PEM_read_X509(file, NULL, NULL, NULL);
1080 VLOG_ERR("PEM_read_X509 failed reading %s: %s",
1081 file_name, ERR_error_string(ERR_get_error(), NULL));
1082 for (i = 0; i < *n_certs; i++) {
1083 X509_free((*certs)[i]);
1091 /* Add certificate to array. */
1092 if (*n_certs >= allocated_certs) {
1093 *certs = x2nrealloc(*certs, &allocated_certs, sizeof **certs);
1095 (*certs)[(*n_certs)++] = certificate;
1097 /* Are there additional certificates in the file? */
1100 } while (isspace(c));
1111 /* Sets 'file_name' as the name of a file containing one or more X509
1112 * certificates to send to the peer. Typical use in OpenFlow is to send the CA
1113 * certificate to the peer, which enables a switch to pick up the controller's
1114 * CA certificate on its first connection. */
1116 stream_ssl_set_peer_ca_cert_file(const char *file_name)
1126 if (!read_cert_file(file_name, &certs, &n_certs)) {
1127 for (i = 0; i < n_certs; i++) {
1128 if (SSL_CTX_add_extra_chain_cert(ctx, certs[i]) != 1) {
1129 VLOG_ERR("SSL_CTX_add_extra_chain_cert: %s",
1130 ERR_error_string(ERR_get_error(), NULL));
1137 /* Logs fingerprint of CA certificate 'cert' obtained from 'file_name'. */
1139 log_ca_cert(const char *file_name, X509 *cert)
1141 unsigned char digest[EVP_MAX_MD_SIZE];
1142 unsigned int n_bytes;
1147 if (!X509_digest(cert, EVP_sha1(), digest, &n_bytes)) {
1148 ds_put_cstr(&fp, "<out of memory>");
1151 for (i = 0; i < n_bytes; i++) {
1153 ds_put_char(&fp, ':');
1155 ds_put_format(&fp, "%02hhx", digest[i]);
1158 subject = X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0);
1159 VLOG_INFO("Trusting CA cert from %s (%s) (fingerprint %s)", file_name,
1160 subject ? subject : "<out of memory>", ds_cstr(&fp));
1166 stream_ssl_set_ca_cert_file__(const char *file_name, bool bootstrap)
1172 if (!strcmp(file_name, "none")) {
1173 verify_peer_cert = false;
1174 VLOG_WARN("Peer certificate validation disabled "
1175 "(this is a security risk)");
1176 } else if (bootstrap && stat(file_name, &s) && errno == ENOENT) {
1177 bootstrap_ca_cert = true;
1178 } else if (!read_cert_file(file_name, &certs, &n_certs)) {
1181 /* Set up list of CAs that the server will accept from the client. */
1182 for (i = 0; i < n_certs; i++) {
1183 /* SSL_CTX_add_client_CA makes a copy of the relevant data. */
1184 if (SSL_CTX_add_client_CA(ctx, certs[i]) != 1) {
1185 VLOG_ERR("failed to add client certificate %d from %s: %s",
1187 ERR_error_string(ERR_get_error(), NULL));
1189 log_ca_cert(file_name, certs[i]);
1191 X509_free(certs[i]);
1195 /* Set up CAs for OpenSSL to trust in verifying the peer's
1197 if (SSL_CTX_load_verify_locations(ctx, file_name, NULL) != 1) {
1198 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
1199 ERR_error_string(ERR_get_error(), NULL));
1203 bootstrap_ca_cert = false;
1205 ca_cert.read = true;
1208 /* Sets 'file_name' as the name of the file from which to read the CA
1209 * certificate used to verify the peer within SSL connections. If 'bootstrap'
1210 * is false, the file must exist. If 'bootstrap' is false, then the file is
1211 * read if it is exists; if it does not, then it will be created from the CA
1212 * certificate received from the peer on the first SSL connection. */
1214 stream_ssl_set_ca_cert_file(const char *file_name, bool bootstrap)
1216 if (!update_ssl_config(&ca_cert, file_name)) {
1220 stream_ssl_set_ca_cert_file__(file_name, bootstrap);
1223 /* SSL protocol logging. */
1226 ssl_alert_level_to_string(uint8_t type)
1229 case 1: return "warning";
1230 case 2: return "fatal";
1231 default: return "<unknown>";
1236 ssl_alert_description_to_string(uint8_t type)
1239 case 0: return "close_notify";
1240 case 10: return "unexpected_message";
1241 case 20: return "bad_record_mac";
1242 case 21: return "decryption_failed";
1243 case 22: return "record_overflow";
1244 case 30: return "decompression_failure";
1245 case 40: return "handshake_failure";
1246 case 42: return "bad_certificate";
1247 case 43: return "unsupported_certificate";
1248 case 44: return "certificate_revoked";
1249 case 45: return "certificate_expired";
1250 case 46: return "certificate_unknown";
1251 case 47: return "illegal_parameter";
1252 case 48: return "unknown_ca";
1253 case 49: return "access_denied";
1254 case 50: return "decode_error";
1255 case 51: return "decrypt_error";
1256 case 60: return "export_restriction";
1257 case 70: return "protocol_version";
1258 case 71: return "insufficient_security";
1259 case 80: return "internal_error";
1260 case 90: return "user_canceled";
1261 case 100: return "no_renegotiation";
1262 default: return "<unknown>";
1267 ssl_handshake_type_to_string(uint8_t type)
1270 case 0: return "hello_request";
1271 case 1: return "client_hello";
1272 case 2: return "server_hello";
1273 case 11: return "certificate";
1274 case 12: return "server_key_exchange";
1275 case 13: return "certificate_request";
1276 case 14: return "server_hello_done";
1277 case 15: return "certificate_verify";
1278 case 16: return "client_key_exchange";
1279 case 20: return "finished";
1280 default: return "<unknown>";
1285 ssl_protocol_cb(int write_p, int version OVS_UNUSED, int content_type,
1286 const void *buf_, size_t len, SSL *ssl OVS_UNUSED, void *sslv_)
1288 const struct ssl_stream *sslv = sslv_;
1289 const uint8_t *buf = buf_;
1292 if (!VLOG_IS_DBG_ENABLED()) {
1297 if (content_type == 20) {
1298 ds_put_cstr(&details, "change_cipher_spec");
1299 } else if (content_type == 21) {
1300 ds_put_format(&details, "alert: %s, %s",
1301 ssl_alert_level_to_string(buf[0]),
1302 ssl_alert_description_to_string(buf[1]));
1303 } else if (content_type == 22) {
1304 ds_put_format(&details, "handshake: %s",
1305 ssl_handshake_type_to_string(buf[0]));
1307 ds_put_format(&details, "type %d", content_type);
1310 VLOG_DBG("%s%u%s%s %s (%zu bytes)",
1311 sslv->type == CLIENT ? "client" : "server",
1312 sslv->session_nr, write_p ? "-->" : "<--",
1313 stream_get_name(&sslv->stream), ds_cstr(&details), len);
1315 ds_destroy(&details);