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 <netinet/tcp.h>
26 #include <openssl/err.h>
27 #include <openssl/ssl.h>
28 #include <openssl/x509v3.h>
30 #include <sys/fcntl.h>
34 #include "dynamic-string.h"
35 #include "leak-checker.h"
37 #include "openflow/openflow.h"
39 #include "poll-loop.h"
41 #include "socket-util.h"
43 #include "stream-provider.h"
48 VLOG_DEFINE_THIS_MODULE(stream_ssl);
66 enum session_type type;
70 unsigned int session_nr;
72 /* rx_want and tx_want record the result of the last call to SSL_read()
73 * and SSL_write(), respectively:
75 * - If the call reported that data needed to be read from the file
76 * descriptor, the corresponding member is set to SSL_READING.
78 * - If the call reported that data needed to be written to the file
79 * descriptor, the corresponding member is set to SSL_WRITING.
81 * - Otherwise, the member is set to SSL_NOTHING, indicating that the
82 * call completed successfully (or with an error) and that there is no
85 * These are needed because there is no way to ask OpenSSL what a data read
86 * or write would require without giving it a buffer to receive into or
87 * data to send, respectively. (Note that the SSL_want() status is
88 * overwritten by each SSL_read() or SSL_write() call, so we can't rely on
91 * A single call to SSL_read() or SSL_write() can perform both reading
92 * and writing and thus invalidate not one of these values but actually
93 * both. Consider this situation, for example:
95 * - SSL_write() blocks on a read, so tx_want gets SSL_READING.
97 * - SSL_read() laters succeeds reading from 'fd' and clears out the
98 * whole receive buffer, so rx_want gets SSL_READING.
100 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
103 * - Now we're stuck blocking until the peer sends us data, even though
104 * SSL_write() could now succeed, which could easily be a deadlock
107 * On the other hand, we can't reset both tx_want and rx_want on every call
108 * to SSL_read() or SSL_write(), because that would produce livelock,
109 * e.g. in this situation:
111 * - SSL_write() blocks, so tx_want gets SSL_READING or SSL_WRITING.
113 * - SSL_read() blocks, so rx_want gets SSL_READING or SSL_WRITING,
114 * but tx_want gets reset to SSL_NOTHING.
116 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
119 * - Client wakes up immediately since SSL_NOTHING in tx_want indicates
120 * that no blocking is necessary.
122 * The solution we adopt here is to set tx_want to SSL_NOTHING after
123 * calling SSL_read() only if the SSL state of the connection changed,
124 * which indicates that an SSL-level renegotiation made some progress, and
125 * similarly for rx_want and SSL_write(). This prevents both the
126 * deadlock and livelock situations above.
128 int rx_want, tx_want;
130 /* A few bytes of header data in case SSL negotiation fails. */
135 /* SSL context created by ssl_init(). */
138 struct ssl_config_file {
139 bool read; /* Whether the file was successfully read. */
140 char *file_name; /* Configured file name, if any. */
141 struct timespec mtime; /* File mtime as of last time we read it. */
144 /* SSL configuration files. */
145 static struct ssl_config_file private_key;
146 static struct ssl_config_file certificate;
147 static struct ssl_config_file ca_cert;
149 /* Ordinarily, the SSL client and server verify each other's certificates using
150 * a CA certificate. Setting this to false disables this behavior. (This is a
152 static bool verify_peer_cert = true;
154 /* Ordinarily, we require a CA certificate for the peer to be locally
155 * available. We can, however, bootstrap the CA certificate from the peer at
156 * the beginning of our first connection then use that certificate on all
157 * subsequent connections, saving it to a file for use in future runs also. In
158 * this case, 'bootstrap_ca_cert' is true. */
159 static bool bootstrap_ca_cert;
161 /* Session number. Used in debug logging messages to uniquely identify a
163 static unsigned int next_session_nr;
165 /* Who knows what can trigger various SSL errors, so let's throttle them down
167 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 25);
169 static int ssl_init(void);
170 static int do_ssl_init(void);
171 static bool ssl_wants_io(int ssl_error);
172 static void ssl_close(struct stream *);
173 static void ssl_clear_txbuf(struct ssl_stream *);
174 static void interpret_queued_ssl_error(const char *function);
175 static int interpret_ssl_error(const char *function, int ret, int error,
177 static DH *tmp_dh_callback(SSL *ssl, int is_export OVS_UNUSED, int keylength);
178 static void log_ca_cert(const char *file_name, X509 *cert);
179 static void stream_ssl_set_ca_cert_file__(const char *file_name,
181 static void ssl_protocol_cb(int write_p, int version, int content_type,
182 const void *, size_t, SSL *, void *sslv_);
185 want_to_poll_events(int want)
203 new_ssl_stream(const char *name, int fd, enum session_type type,
204 enum ssl_state state, const struct sockaddr_in *remote,
205 struct stream **streamp)
207 struct sockaddr_in local;
208 socklen_t local_len = sizeof local;
209 struct ssl_stream *sslv;
214 /* Check for all the needful configuration. */
216 if (!private_key.read) {
217 VLOG_ERR("Private key must be configured to use SSL");
218 retval = ENOPROTOOPT;
220 if (!certificate.read) {
221 VLOG_ERR("Certificate must be configured to use SSL");
222 retval = ENOPROTOOPT;
224 if (!ca_cert.read && verify_peer_cert && !bootstrap_ca_cert) {
225 VLOG_ERR("CA certificate must be configured to use SSL");
226 retval = ENOPROTOOPT;
228 if (!SSL_CTX_check_private_key(ctx)) {
229 VLOG_ERR("Private key does not match certificate public key: %s",
230 ERR_error_string(ERR_get_error(), NULL));
231 retval = ENOPROTOOPT;
237 /* Get the local IP and port information */
238 retval = getsockname(fd, (struct sockaddr *) &local, &local_len);
240 memset(&local, 0, sizeof local);
244 retval = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof on);
246 VLOG_ERR("%s: setsockopt(TCP_NODELAY): %s", name, strerror(errno));
251 /* Create and configure OpenSSL stream. */
254 VLOG_ERR("SSL_new: %s", ERR_error_string(ERR_get_error(), NULL));
255 retval = ENOPROTOOPT;
258 if (SSL_set_fd(ssl, fd) == 0) {
259 VLOG_ERR("SSL_set_fd: %s", ERR_error_string(ERR_get_error(), NULL));
260 retval = ENOPROTOOPT;
263 if (!verify_peer_cert || (bootstrap_ca_cert && type == CLIENT)) {
264 SSL_set_verify(ssl, SSL_VERIFY_NONE, NULL);
267 /* Create and return the ssl_stream. */
268 sslv = xmalloc(sizeof *sslv);
269 stream_init(&sslv->stream, &ssl_stream_class, EAGAIN, name);
270 stream_set_remote_ip(&sslv->stream, remote->sin_addr.s_addr);
271 stream_set_remote_port(&sslv->stream, remote->sin_port);
272 stream_set_local_ip(&sslv->stream, local.sin_addr.s_addr);
273 stream_set_local_port(&sslv->stream, local.sin_port);
279 sslv->rx_want = sslv->tx_want = SSL_NOTHING;
280 sslv->session_nr = next_session_nr++;
283 if (VLOG_IS_DBG_ENABLED()) {
284 SSL_set_msg_callback(ssl, ssl_protocol_cb);
285 SSL_set_msg_callback_arg(ssl, sslv);
288 *streamp = &sslv->stream;
299 static struct ssl_stream *
300 ssl_stream_cast(struct stream *stream)
302 stream_assert_class(stream, &ssl_stream_class);
303 return CONTAINER_OF(stream, struct ssl_stream, stream);
307 ssl_open(const char *name, char *suffix, struct stream **streamp)
309 struct sockaddr_in sin;
317 error = inet_open_active(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin, &fd);
319 int state = error ? STATE_TCP_CONNECTING : STATE_SSL_CONNECTING;
320 return new_ssl_stream(name, fd, CLIENT, state, &sin, streamp);
322 VLOG_ERR("%s: connect: %s", name, strerror(error));
328 do_ca_cert_bootstrap(struct stream *stream)
330 struct ssl_stream *sslv = ssl_stream_cast(stream);
331 STACK_OF(X509) *chain;
337 chain = SSL_get_peer_cert_chain(sslv->ssl);
338 if (!chain || !sk_X509_num(chain)) {
339 VLOG_ERR("could not bootstrap CA cert: no certificate presented by "
343 cert = sk_X509_value(chain, sk_X509_num(chain) - 1);
345 /* Check that 'cert' is self-signed. Otherwise it is not a CA
346 * certificate and we should not attempt to use it as one. */
347 error = X509_check_issued(cert, cert);
349 VLOG_ERR("could not bootstrap CA cert: obtained certificate is "
350 "not self-signed (%s)",
351 X509_verify_cert_error_string(error));
352 if (sk_X509_num(chain) < 2) {
353 VLOG_ERR("only one certificate was received, so probably the peer "
354 "is not configured to send its CA certificate");
359 fd = open(ca_cert.file_name, O_CREAT | O_EXCL | O_WRONLY, 0444);
361 if (errno == EEXIST) {
362 VLOG_INFO("reading CA cert %s created by another process",
364 stream_ssl_set_ca_cert_file(ca_cert.file_name, true);
367 VLOG_ERR("could not bootstrap CA cert: creating %s failed: %s",
368 ca_cert.file_name, strerror(errno));
373 file = fdopen(fd, "w");
376 VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s",
378 unlink(ca_cert.file_name);
382 if (!PEM_write_X509(file, cert)) {
383 VLOG_ERR("could not bootstrap CA cert: PEM_write_X509 to %s failed: "
384 "%s", ca_cert.file_name,
385 ERR_error_string(ERR_get_error(), NULL));
387 unlink(ca_cert.file_name);
393 VLOG_ERR("could not bootstrap CA cert: writing %s failed: %s",
394 ca_cert.file_name, strerror(error));
395 unlink(ca_cert.file_name);
399 VLOG_INFO("successfully bootstrapped CA cert to %s", ca_cert.file_name);
400 log_ca_cert(ca_cert.file_name, cert);
401 bootstrap_ca_cert = false;
404 /* SSL_CTX_add_client_CA makes a copy of cert's relevant data. */
405 SSL_CTX_add_client_CA(ctx, cert);
407 /* SSL_CTX_use_certificate() takes ownership of the certificate passed in.
408 * 'cert' is owned by sslv->ssl, so we need to duplicate it. */
409 cert = X509_dup(cert);
413 if (SSL_CTX_load_verify_locations(ctx, ca_cert.file_name, NULL) != 1) {
414 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
415 ERR_error_string(ERR_get_error(), NULL));
418 VLOG_INFO("killing successful connection to retry using CA cert");
423 ssl_connect(struct stream *stream)
425 struct ssl_stream *sslv = ssl_stream_cast(stream);
428 switch (sslv->state) {
429 case STATE_TCP_CONNECTING:
430 retval = check_connection_completion(sslv->fd);
434 sslv->state = STATE_SSL_CONNECTING;
437 case STATE_SSL_CONNECTING:
438 /* Capture the first few bytes of received data so that we can guess
439 * what kind of funny data we've been sent if SSL negotation fails. */
440 if (sslv->n_head <= 0) {
441 sslv->n_head = recv(sslv->fd, sslv->head, sizeof sslv->head,
445 retval = (sslv->type == CLIENT
446 ? SSL_connect(sslv->ssl) : SSL_accept(sslv->ssl));
448 int error = SSL_get_error(sslv->ssl, retval);
449 if (retval < 0 && ssl_wants_io(error)) {
454 interpret_ssl_error((sslv->type == CLIENT ? "SSL_connect"
455 : "SSL_accept"), retval, error, &unused);
456 shutdown(sslv->fd, SHUT_RDWR);
457 stream_report_content(sslv->head, sslv->n_head, STREAM_SSL,
458 THIS_MODULE, stream_get_name(stream));
461 } else if (bootstrap_ca_cert) {
462 return do_ca_cert_bootstrap(stream);
463 } else if (verify_peer_cert
464 && ((SSL_get_verify_mode(sslv->ssl)
465 & (SSL_VERIFY_NONE | SSL_VERIFY_PEER))
466 != SSL_VERIFY_PEER)) {
467 /* Two or more SSL connections completed at the same time while we
468 * were in bootstrap mode. Only one of these can finish the
469 * bootstrap successfully. The other one(s) must be rejected
470 * because they were not verified against the bootstrapped CA
471 * certificate. (Alternatively we could verify them against the CA
472 * certificate, but that's more trouble than it's worth. These
473 * connections will succeed the next time they retry, assuming that
474 * they have a certificate against the correct CA.) */
475 VLOG_ERR("rejecting SSL connection during bootstrap race window");
486 ssl_close(struct stream *stream)
488 struct ssl_stream *sslv = ssl_stream_cast(stream);
489 ssl_clear_txbuf(sslv);
491 /* Attempt clean shutdown of the SSL connection. This will work most of
492 * the time, as long as the kernel send buffer has some free space and the
493 * SSL connection isn't renegotiating, etc. That has to be good enough,
494 * since we don't have any way to continue the close operation in the
496 SSL_shutdown(sslv->ssl);
498 /* SSL_shutdown() might have signaled an error, in which case we need to
499 * flush it out of the OpenSSL error queue or the next OpenSSL operation
500 * will falsely signal an error. */
509 interpret_queued_ssl_error(const char *function)
511 int queued_error = ERR_get_error();
512 if (queued_error != 0) {
513 VLOG_WARN_RL(&rl, "%s: %s",
514 function, ERR_error_string(queued_error, NULL));
516 VLOG_ERR_RL(&rl, "%s: SSL_ERROR_SSL without queued error", function);
521 interpret_ssl_error(const char *function, int ret, int error,
528 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_NONE", function);
531 case SSL_ERROR_ZERO_RETURN:
532 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_ZERO_RETURN", function);
535 case SSL_ERROR_WANT_READ:
539 case SSL_ERROR_WANT_WRITE:
543 case SSL_ERROR_WANT_CONNECT:
544 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_CONNECT", function);
547 case SSL_ERROR_WANT_ACCEPT:
548 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_ACCEPT", function);
551 case SSL_ERROR_WANT_X509_LOOKUP:
552 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_X509_LOOKUP",
556 case SSL_ERROR_SYSCALL: {
557 int queued_error = ERR_get_error();
558 if (queued_error == 0) {
561 VLOG_WARN_RL(&rl, "%s: system error (%s)",
562 function, strerror(status));
565 VLOG_WARN_RL(&rl, "%s: unexpected SSL connection close",
570 VLOG_WARN_RL(&rl, "%s: %s",
571 function, ERR_error_string(queued_error, NULL));
577 interpret_queued_ssl_error(function);
581 VLOG_ERR_RL(&rl, "%s: bad SSL error code %d", function, error);
588 ssl_recv(struct stream *stream, void *buffer, size_t n)
590 struct ssl_stream *sslv = ssl_stream_cast(stream);
594 /* Behavior of zero-byte SSL_read is poorly defined. */
597 old_state = SSL_get_state(sslv->ssl);
598 ret = SSL_read(sslv->ssl, buffer, n);
599 if (old_state != SSL_get_state(sslv->ssl)) {
600 sslv->tx_want = SSL_NOTHING;
602 sslv->rx_want = SSL_NOTHING;
607 int error = SSL_get_error(sslv->ssl, ret);
608 if (error == SSL_ERROR_ZERO_RETURN) {
611 return -interpret_ssl_error("SSL_read", ret, error,
618 ssl_clear_txbuf(struct ssl_stream *sslv)
620 ofpbuf_delete(sslv->txbuf);
625 ssl_do_tx(struct stream *stream)
627 struct ssl_stream *sslv = ssl_stream_cast(stream);
630 int old_state = SSL_get_state(sslv->ssl);
631 int ret = SSL_write(sslv->ssl, sslv->txbuf->data, sslv->txbuf->size);
632 if (old_state != SSL_get_state(sslv->ssl)) {
633 sslv->rx_want = SSL_NOTHING;
635 sslv->tx_want = SSL_NOTHING;
637 ofpbuf_pull(sslv->txbuf, ret);
638 if (sslv->txbuf->size == 0) {
642 int ssl_error = SSL_get_error(sslv->ssl, ret);
643 if (ssl_error == SSL_ERROR_ZERO_RETURN) {
644 VLOG_WARN_RL(&rl, "SSL_write: connection closed");
647 return interpret_ssl_error("SSL_write", ret, ssl_error,
655 ssl_send(struct stream *stream, const void *buffer, size_t n)
657 struct ssl_stream *sslv = ssl_stream_cast(stream);
664 sslv->txbuf = ofpbuf_clone_data(buffer, n);
665 error = ssl_do_tx(stream);
668 ssl_clear_txbuf(sslv);
671 leak_checker_claim(buffer);
681 ssl_run(struct stream *stream)
683 struct ssl_stream *sslv = ssl_stream_cast(stream);
685 if (sslv->txbuf && ssl_do_tx(stream) != EAGAIN) {
686 ssl_clear_txbuf(sslv);
691 ssl_run_wait(struct stream *stream)
693 struct ssl_stream *sslv = ssl_stream_cast(stream);
695 if (sslv->tx_want != SSL_NOTHING) {
696 poll_fd_wait(sslv->fd, want_to_poll_events(sslv->tx_want));
701 ssl_wait(struct stream *stream, enum stream_wait_type wait)
703 struct ssl_stream *sslv = ssl_stream_cast(stream);
707 if (stream_connect(stream) != EAGAIN) {
708 poll_immediate_wake();
710 switch (sslv->state) {
711 case STATE_TCP_CONNECTING:
712 poll_fd_wait(sslv->fd, POLLOUT);
715 case STATE_SSL_CONNECTING:
716 /* ssl_connect() called SSL_accept() or SSL_connect(), which
717 * set up the status that we test here. */
718 poll_fd_wait(sslv->fd,
719 want_to_poll_events(SSL_want(sslv->ssl)));
729 if (sslv->rx_want != SSL_NOTHING) {
730 poll_fd_wait(sslv->fd, want_to_poll_events(sslv->rx_want));
732 poll_immediate_wake();
738 /* We have room in our tx queue. */
739 poll_immediate_wake();
741 /* stream_run_wait() will do the right thing; don't bother with
751 struct stream_class ssl_stream_class = {
754 ssl_close, /* close */
755 ssl_connect, /* connect */
759 ssl_run_wait, /* run_wait */
767 struct pstream pstream;
771 struct pstream_class pssl_pstream_class;
773 static struct pssl_pstream *
774 pssl_pstream_cast(struct pstream *pstream)
776 pstream_assert_class(pstream, &pssl_pstream_class);
777 return CONTAINER_OF(pstream, struct pssl_pstream, pstream);
781 pssl_open(const char *name OVS_UNUSED, char *suffix, struct pstream **pstreamp)
783 struct pssl_pstream *pssl;
784 struct sockaddr_in sin;
785 char bound_name[128];
794 fd = inet_open_passive(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin);
798 sprintf(bound_name, "pssl:%"PRIu16":"IP_FMT,
799 ntohs(sin.sin_port), IP_ARGS(&sin.sin_addr.s_addr));
801 pssl = xmalloc(sizeof *pssl);
802 pstream_init(&pssl->pstream, &pssl_pstream_class, bound_name);
804 *pstreamp = &pssl->pstream;
809 pssl_close(struct pstream *pstream)
811 struct pssl_pstream *pssl = pssl_pstream_cast(pstream);
817 pssl_accept(struct pstream *pstream, struct stream **new_streamp)
819 struct pssl_pstream *pssl = pssl_pstream_cast(pstream);
820 struct sockaddr_in sin;
821 socklen_t sin_len = sizeof sin;
826 new_fd = accept(pssl->fd, &sin, &sin_len);
829 if (error != EAGAIN) {
830 VLOG_DBG_RL(&rl, "accept: %s", strerror(error));
835 error = set_nonblocking(new_fd);
841 sprintf(name, "ssl:"IP_FMT, IP_ARGS(&sin.sin_addr));
842 if (sin.sin_port != htons(OFP_SSL_PORT)) {
843 sprintf(strchr(name, '\0'), ":%"PRIu16, ntohs(sin.sin_port));
845 return new_ssl_stream(name, new_fd, SERVER, STATE_SSL_CONNECTING, &sin,
850 pssl_wait(struct pstream *pstream)
852 struct pssl_pstream *pssl = pssl_pstream_cast(pstream);
853 poll_fd_wait(pssl->fd, POLLIN);
856 struct pstream_class pssl_pstream_class = {
865 * Returns true if OpenSSL error is WANT_READ or WANT_WRITE, indicating that
866 * OpenSSL is requesting that we call it back when the socket is ready for read
867 * or writing, respectively.
870 ssl_wants_io(int ssl_error)
872 return (ssl_error == SSL_ERROR_WANT_WRITE
873 || ssl_error == SSL_ERROR_WANT_READ);
879 static int init_status = -1;
880 if (init_status < 0) {
881 init_status = do_ssl_init();
882 assert(init_status >= 0);
893 SSL_load_error_strings();
895 /* New OpenSSL changed TLSv1_method() to return a "const" pointer, so the
896 * cast is needed to avoid a warning with those newer versions. */
897 method = (SSL_METHOD *) TLSv1_method();
898 if (method == NULL) {
899 VLOG_ERR("TLSv1_method: %s", ERR_error_string(ERR_get_error(), NULL));
903 ctx = SSL_CTX_new(method);
905 VLOG_ERR("SSL_CTX_new: %s", ERR_error_string(ERR_get_error(), NULL));
908 SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
909 SSL_CTX_set_tmp_dh_callback(ctx, tmp_dh_callback);
910 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
911 SSL_CTX_set_mode(ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
912 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
919 tmp_dh_callback(SSL *ssl OVS_UNUSED, int is_export OVS_UNUSED, int keylength)
924 DH *(*constructor)(void);
927 static struct dh dh_table[] = {
928 {1024, NULL, get_dh1024},
929 {2048, NULL, get_dh2048},
930 {4096, NULL, get_dh4096},
935 for (dh = dh_table; dh < &dh_table[ARRAY_SIZE(dh_table)]; dh++) {
936 if (dh->keylength == keylength) {
938 dh->dh = dh->constructor();
940 ovs_fatal(ENOMEM, "out of memory constructing "
941 "Diffie-Hellman parameters");
947 VLOG_ERR_RL(&rl, "no Diffie-Hellman parameters for key length %d",
952 /* Returns true if SSL is at least partially configured. */
954 stream_ssl_is_configured(void)
956 return private_key.file_name || certificate.file_name || ca_cert.file_name;
960 update_ssl_config(struct ssl_config_file *config, const char *file_name)
962 struct timespec mtime;
964 if (ssl_init() || !file_name) {
968 /* If the file name hasn't changed and neither has the file contents, stop
970 get_mtime(file_name, &mtime);
971 if (config->file_name
972 && !strcmp(config->file_name, file_name)
973 && mtime.tv_sec == config->mtime.tv_sec
974 && mtime.tv_nsec == config->mtime.tv_nsec) {
978 /* Update 'config'. */
979 config->mtime = mtime;
980 if (file_name != config->file_name) {
981 free(config->file_name);
982 config->file_name = xstrdup(file_name);
988 stream_ssl_set_private_key_file__(const char *file_name)
990 if (SSL_CTX_use_PrivateKey_file(ctx, file_name, SSL_FILETYPE_PEM) == 1) {
991 private_key.read = true;
993 VLOG_ERR("SSL_use_PrivateKey_file: %s",
994 ERR_error_string(ERR_get_error(), NULL));
999 stream_ssl_set_private_key_file(const char *file_name)
1001 if (update_ssl_config(&private_key, file_name)) {
1002 stream_ssl_set_private_key_file__(file_name);
1007 stream_ssl_set_certificate_file__(const char *file_name)
1009 if (SSL_CTX_use_certificate_chain_file(ctx, file_name) == 1) {
1010 certificate.read = true;
1012 VLOG_ERR("SSL_use_certificate_file: %s",
1013 ERR_error_string(ERR_get_error(), NULL));
1018 stream_ssl_set_certificate_file(const char *file_name)
1020 if (update_ssl_config(&certificate, file_name)) {
1021 stream_ssl_set_certificate_file__(file_name);
1025 /* Sets the private key and certificate files in one operation. Use this
1026 * interface, instead of calling stream_ssl_set_private_key_file() and
1027 * stream_ssl_set_certificate_file() individually, in the main loop of a
1028 * long-running program whose key and certificate might change at runtime.
1030 * This is important because of OpenSSL's behavior. If an OpenSSL context
1031 * already has a certificate, and stream_ssl_set_private_key_file() is called
1032 * to install a new private key, OpenSSL will report an error because the new
1033 * private key does not match the old certificate. The other order, of setting
1034 * a new certificate, then setting a new private key, does work.
1036 * If this were the only problem, calling stream_ssl_set_certificate_file()
1037 * before stream_ssl_set_private_key_file() would fix it. But, if the private
1038 * key is changed before the certificate (e.g. someone "scp"s or "mv"s the new
1039 * private key in place before the certificate), then OpenSSL would reject that
1040 * change, and then the change of certificate would succeed, but there would be
1041 * no associated private key (because it had only changed once and therefore
1042 * there was no point in re-reading it).
1044 * This function avoids both problems by, whenever either the certificate or
1045 * the private key file changes, re-reading both of them, in the correct order.
1048 stream_ssl_set_key_and_cert(const char *private_key_file,
1049 const char *certificate_file)
1051 if (update_ssl_config(&private_key, private_key_file)
1052 || update_ssl_config(&certificate, certificate_file)) {
1053 stream_ssl_set_certificate_file__(certificate_file);
1054 stream_ssl_set_private_key_file__(private_key_file);
1058 /* Reads the X509 certificate or certificates in file 'file_name'. On success,
1059 * stores the address of the first element in an array of pointers to
1060 * certificates in '*certs' and the number of certificates in the array in
1061 * '*n_certs', and returns 0. On failure, stores a null pointer in '*certs', 0
1062 * in '*n_certs', and returns a positive errno value.
1064 * The caller is responsible for freeing '*certs'. */
1066 read_cert_file(const char *file_name, X509 ***certs, size_t *n_certs)
1069 size_t allocated_certs = 0;
1074 file = fopen(file_name, "r");
1076 VLOG_ERR("failed to open %s for reading: %s",
1077 file_name, strerror(errno));
1085 /* Read certificate from file. */
1086 certificate = PEM_read_X509(file, NULL, NULL, NULL);
1090 VLOG_ERR("PEM_read_X509 failed reading %s: %s",
1091 file_name, ERR_error_string(ERR_get_error(), NULL));
1092 for (i = 0; i < *n_certs; i++) {
1093 X509_free((*certs)[i]);
1101 /* Add certificate to array. */
1102 if (*n_certs >= allocated_certs) {
1103 *certs = x2nrealloc(*certs, &allocated_certs, sizeof **certs);
1105 (*certs)[(*n_certs)++] = certificate;
1107 /* Are there additional certificates in the file? */
1110 } while (isspace(c));
1121 /* Sets 'file_name' as the name of a file containing one or more X509
1122 * certificates to send to the peer. Typical use in OpenFlow is to send the CA
1123 * certificate to the peer, which enables a switch to pick up the controller's
1124 * CA certificate on its first connection. */
1126 stream_ssl_set_peer_ca_cert_file(const char *file_name)
1136 if (!read_cert_file(file_name, &certs, &n_certs)) {
1137 for (i = 0; i < n_certs; i++) {
1138 if (SSL_CTX_add_extra_chain_cert(ctx, certs[i]) != 1) {
1139 VLOG_ERR("SSL_CTX_add_extra_chain_cert: %s",
1140 ERR_error_string(ERR_get_error(), NULL));
1147 /* Logs fingerprint of CA certificate 'cert' obtained from 'file_name'. */
1149 log_ca_cert(const char *file_name, X509 *cert)
1151 unsigned char digest[EVP_MAX_MD_SIZE];
1152 unsigned int n_bytes;
1157 if (!X509_digest(cert, EVP_sha1(), digest, &n_bytes)) {
1158 ds_put_cstr(&fp, "<out of memory>");
1161 for (i = 0; i < n_bytes; i++) {
1163 ds_put_char(&fp, ':');
1165 ds_put_format(&fp, "%02hhx", digest[i]);
1168 subject = X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0);
1169 VLOG_INFO("Trusting CA cert from %s (%s) (fingerprint %s)", file_name,
1170 subject ? subject : "<out of memory>", ds_cstr(&fp));
1171 OPENSSL_free(subject);
1176 stream_ssl_set_ca_cert_file__(const char *file_name, bool bootstrap)
1182 if (!strcmp(file_name, "none")) {
1183 verify_peer_cert = false;
1184 VLOG_WARN("Peer certificate validation disabled "
1185 "(this is a security risk)");
1186 } else if (bootstrap && stat(file_name, &s) && errno == ENOENT) {
1187 bootstrap_ca_cert = true;
1188 } else if (!read_cert_file(file_name, &certs, &n_certs)) {
1191 /* Set up list of CAs that the server will accept from the client. */
1192 for (i = 0; i < n_certs; i++) {
1193 /* SSL_CTX_add_client_CA makes a copy of the relevant data. */
1194 if (SSL_CTX_add_client_CA(ctx, certs[i]) != 1) {
1195 VLOG_ERR("failed to add client certificate %zu from %s: %s",
1197 ERR_error_string(ERR_get_error(), NULL));
1199 log_ca_cert(file_name, certs[i]);
1201 X509_free(certs[i]);
1205 /* Set up CAs for OpenSSL to trust in verifying the peer's
1207 if (SSL_CTX_load_verify_locations(ctx, file_name, NULL) != 1) {
1208 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
1209 ERR_error_string(ERR_get_error(), NULL));
1213 bootstrap_ca_cert = false;
1215 ca_cert.read = true;
1218 /* Sets 'file_name' as the name of the file from which to read the CA
1219 * certificate used to verify the peer within SSL connections. If 'bootstrap'
1220 * is false, the file must exist. If 'bootstrap' is false, then the file is
1221 * read if it is exists; if it does not, then it will be created from the CA
1222 * certificate received from the peer on the first SSL connection. */
1224 stream_ssl_set_ca_cert_file(const char *file_name, bool bootstrap)
1226 if (!update_ssl_config(&ca_cert, file_name)) {
1230 stream_ssl_set_ca_cert_file__(file_name, bootstrap);
1233 /* SSL protocol logging. */
1236 ssl_alert_level_to_string(uint8_t type)
1239 case 1: return "warning";
1240 case 2: return "fatal";
1241 default: return "<unknown>";
1246 ssl_alert_description_to_string(uint8_t type)
1249 case 0: return "close_notify";
1250 case 10: return "unexpected_message";
1251 case 20: return "bad_record_mac";
1252 case 21: return "decryption_failed";
1253 case 22: return "record_overflow";
1254 case 30: return "decompression_failure";
1255 case 40: return "handshake_failure";
1256 case 42: return "bad_certificate";
1257 case 43: return "unsupported_certificate";
1258 case 44: return "certificate_revoked";
1259 case 45: return "certificate_expired";
1260 case 46: return "certificate_unknown";
1261 case 47: return "illegal_parameter";
1262 case 48: return "unknown_ca";
1263 case 49: return "access_denied";
1264 case 50: return "decode_error";
1265 case 51: return "decrypt_error";
1266 case 60: return "export_restriction";
1267 case 70: return "protocol_version";
1268 case 71: return "insufficient_security";
1269 case 80: return "internal_error";
1270 case 90: return "user_canceled";
1271 case 100: return "no_renegotiation";
1272 default: return "<unknown>";
1277 ssl_handshake_type_to_string(uint8_t type)
1280 case 0: return "hello_request";
1281 case 1: return "client_hello";
1282 case 2: return "server_hello";
1283 case 11: return "certificate";
1284 case 12: return "server_key_exchange";
1285 case 13: return "certificate_request";
1286 case 14: return "server_hello_done";
1287 case 15: return "certificate_verify";
1288 case 16: return "client_key_exchange";
1289 case 20: return "finished";
1290 default: return "<unknown>";
1295 ssl_protocol_cb(int write_p, int version OVS_UNUSED, int content_type,
1296 const void *buf_, size_t len, SSL *ssl OVS_UNUSED, void *sslv_)
1298 const struct ssl_stream *sslv = sslv_;
1299 const uint8_t *buf = buf_;
1302 if (!VLOG_IS_DBG_ENABLED()) {
1307 if (content_type == 20) {
1308 ds_put_cstr(&details, "change_cipher_spec");
1309 } else if (content_type == 21) {
1310 ds_put_format(&details, "alert: %s, %s",
1311 ssl_alert_level_to_string(buf[0]),
1312 ssl_alert_description_to_string(buf[1]));
1313 } else if (content_type == 22) {
1314 ds_put_format(&details, "handshake: %s",
1315 ssl_handshake_type_to_string(buf[0]));
1317 ds_put_format(&details, "type %d", content_type);
1320 VLOG_DBG("%s%u%s%s %s (%zu bytes)",
1321 sslv->type == CLIENT ? "client" : "server",
1322 sslv->session_nr, write_p ? "-->" : "<--",
1323 stream_get_name(&sslv->stream), ds_cstr(&details), len);
1325 ds_destroy(&details);