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"
40 #include "socket-util.h"
42 #include "stream-provider.h"
47 #define THIS_MODULE VLM_stream_ssl
66 enum session_type type;
71 /* rx_want and tx_want record the result of the last call to SSL_read()
72 * and SSL_write(), respectively:
74 * - If the call reported that data needed to be read from the file
75 * descriptor, the corresponding member is set to SSL_READING.
77 * - If the call reported that data needed to be written to the file
78 * descriptor, the corresponding member is set to SSL_WRITING.
80 * - Otherwise, the member is set to SSL_NOTHING, indicating that the
81 * call completed successfully (or with an error) and that there is no
84 * These are needed because there is no way to ask OpenSSL what a data read
85 * or write would require without giving it a buffer to receive into or
86 * data to send, respectively. (Note that the SSL_want() status is
87 * overwritten by each SSL_read() or SSL_write() call, so we can't rely on
90 * A single call to SSL_read() or SSL_write() can perform both reading
91 * and writing and thus invalidate not one of these values but actually
92 * both. Consider this situation, for example:
94 * - SSL_write() blocks on a read, so tx_want gets SSL_READING.
96 * - SSL_read() laters succeeds reading from 'fd' and clears out the
97 * whole receive buffer, so rx_want gets SSL_READING.
99 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
102 * - Now we're stuck blocking until the peer sends us data, even though
103 * SSL_write() could now succeed, which could easily be a deadlock
106 * On the other hand, we can't reset both tx_want and rx_want on every call
107 * to SSL_read() or SSL_write(), because that would produce livelock,
108 * e.g. in this situation:
110 * - SSL_write() blocks, so tx_want gets SSL_READING or SSL_WRITING.
112 * - SSL_read() blocks, so rx_want gets SSL_READING or SSL_WRITING,
113 * but tx_want gets reset to SSL_NOTHING.
115 * - Client calls stream_wait(STREAM_RECV) and stream_wait(STREAM_SEND)
118 * - Client wakes up immediately since SSL_NOTHING in tx_want indicates
119 * that no blocking is necessary.
121 * The solution we adopt here is to set tx_want to SSL_NOTHING after
122 * calling SSL_read() only if the SSL state of the connection changed,
123 * which indicates that an SSL-level renegotiation made some progress, and
124 * similarly for rx_want and SSL_write(). This prevents both the
125 * deadlock and livelock situations above.
127 int rx_want, tx_want;
130 /* SSL context created by ssl_init(). */
133 struct ssl_config_file {
134 bool read; /* Whether the file was successfully read. */
135 char *file_name; /* Configured file name, if any. */
136 struct timespec mtime; /* File mtime as of last time we read it. */
139 /* SSL configuration files. */
140 static struct ssl_config_file private_key;
141 static struct ssl_config_file certificate;
142 static struct ssl_config_file ca_cert;
144 /* Ordinarily, we require a CA certificate for the peer to be locally
145 * available. We can, however, bootstrap the CA certificate from the peer at
146 * the beginning of our first connection then use that certificate on all
147 * subsequent connections, saving it to a file for use in future runs also. In
148 * this case, 'bootstrap_ca_cert' is true. */
149 static bool bootstrap_ca_cert;
151 /* Who knows what can trigger various SSL errors, so let's throttle them down
153 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 25);
155 static int ssl_init(void);
156 static int do_ssl_init(void);
157 static bool ssl_wants_io(int ssl_error);
158 static void ssl_close(struct stream *);
159 static void ssl_clear_txbuf(struct ssl_stream *);
160 static int interpret_ssl_error(const char *function, int ret, int error,
162 static DH *tmp_dh_callback(SSL *ssl, int is_export OVS_UNUSED, int keylength);
163 static void log_ca_cert(const char *file_name, X509 *cert);
164 static void stream_ssl_set_ca_cert_file__(const char *file_name,
168 want_to_poll_events(int want)
186 new_ssl_stream(const char *name, int fd, enum session_type type,
187 enum ssl_state state, const struct sockaddr_in *remote,
188 struct stream **streamp)
190 struct sockaddr_in local;
191 socklen_t local_len = sizeof local;
192 struct ssl_stream *sslv;
197 /* Check for all the needful configuration. */
199 if (!private_key.read) {
200 VLOG_ERR("Private key must be configured to use SSL");
201 retval = ENOPROTOOPT;
203 if (!certificate.read) {
204 VLOG_ERR("Certificate must be configured to use SSL");
205 retval = ENOPROTOOPT;
207 if (!ca_cert.read && !bootstrap_ca_cert) {
208 VLOG_ERR("CA certificate must be configured to use SSL");
209 retval = ENOPROTOOPT;
211 if (!SSL_CTX_check_private_key(ctx)) {
212 VLOG_ERR("Private key does not match certificate public key: %s",
213 ERR_error_string(ERR_get_error(), NULL));
214 retval = ENOPROTOOPT;
220 /* Get the local IP and port information */
221 retval = getsockname(fd, (struct sockaddr *) &local, &local_len);
223 memset(&local, 0, sizeof local);
227 retval = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof on);
229 VLOG_ERR("%s: setsockopt(TCP_NODELAY): %s", name, strerror(errno));
234 /* Create and configure OpenSSL stream. */
237 VLOG_ERR("SSL_new: %s", ERR_error_string(ERR_get_error(), NULL));
238 retval = ENOPROTOOPT;
241 if (SSL_set_fd(ssl, fd) == 0) {
242 VLOG_ERR("SSL_set_fd: %s", ERR_error_string(ERR_get_error(), NULL));
243 retval = ENOPROTOOPT;
246 if (bootstrap_ca_cert && type == CLIENT) {
247 SSL_set_verify(ssl, SSL_VERIFY_NONE, NULL);
250 /* Create and return the ssl_stream. */
251 sslv = xmalloc(sizeof *sslv);
252 stream_init(&sslv->stream, &ssl_stream_class, EAGAIN, name);
253 stream_set_remote_ip(&sslv->stream, remote->sin_addr.s_addr);
254 stream_set_remote_port(&sslv->stream, remote->sin_port);
255 stream_set_local_ip(&sslv->stream, local.sin_addr.s_addr);
256 stream_set_local_port(&sslv->stream, local.sin_port);
262 sslv->rx_want = sslv->tx_want = SSL_NOTHING;
263 *streamp = &sslv->stream;
274 static struct ssl_stream *
275 ssl_stream_cast(struct stream *stream)
277 stream_assert_class(stream, &ssl_stream_class);
278 return CONTAINER_OF(stream, struct ssl_stream, stream);
282 ssl_open(const char *name, char *suffix, struct stream **streamp)
284 struct sockaddr_in sin;
292 error = inet_open_active(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin, &fd);
294 int state = error ? STATE_TCP_CONNECTING : STATE_SSL_CONNECTING;
295 return new_ssl_stream(name, fd, CLIENT, state, &sin, streamp);
297 VLOG_ERR("%s: connect: %s", name, strerror(error));
303 do_ca_cert_bootstrap(struct stream *stream)
305 struct ssl_stream *sslv = ssl_stream_cast(stream);
306 STACK_OF(X509) *chain;
312 chain = SSL_get_peer_cert_chain(sslv->ssl);
313 if (!chain || !sk_X509_num(chain)) {
314 VLOG_ERR("could not bootstrap CA cert: no certificate presented by "
318 cert = sk_X509_value(chain, sk_X509_num(chain) - 1);
320 /* Check that 'cert' is self-signed. Otherwise it is not a CA
321 * certificate and we should not attempt to use it as one. */
322 error = X509_check_issued(cert, cert);
324 VLOG_ERR("could not bootstrap CA cert: obtained certificate is "
325 "not self-signed (%s)",
326 X509_verify_cert_error_string(error));
327 if (sk_X509_num(chain) < 2) {
328 VLOG_ERR("only one certificate was received, so probably the peer "
329 "is not configured to send its CA certificate");
334 fd = open(ca_cert.file_name, O_CREAT | O_EXCL | O_WRONLY, 0444);
336 if (errno == EEXIST) {
337 VLOG_INFO("reading CA cert %s created by another process",
339 stream_ssl_set_ca_cert_file(ca_cert.file_name, true);
342 VLOG_ERR("could not bootstrap CA cert: creating %s failed: %s",
343 ca_cert.file_name, strerror(errno));
348 file = fdopen(fd, "w");
351 VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s",
353 unlink(ca_cert.file_name);
357 if (!PEM_write_X509(file, cert)) {
358 VLOG_ERR("could not bootstrap CA cert: PEM_write_X509 to %s failed: "
359 "%s", ca_cert.file_name,
360 ERR_error_string(ERR_get_error(), NULL));
362 unlink(ca_cert.file_name);
368 VLOG_ERR("could not bootstrap CA cert: writing %s failed: %s",
369 ca_cert.file_name, strerror(error));
370 unlink(ca_cert.file_name);
374 VLOG_INFO("successfully bootstrapped CA cert to %s", ca_cert.file_name);
375 log_ca_cert(ca_cert.file_name, cert);
376 bootstrap_ca_cert = false;
379 /* SSL_CTX_add_client_CA makes a copy of cert's relevant data. */
380 SSL_CTX_add_client_CA(ctx, cert);
382 /* SSL_CTX_use_certificate() takes ownership of the certificate passed in.
383 * 'cert' is owned by sslv->ssl, so we need to duplicate it. */
384 cert = X509_dup(cert);
388 if (SSL_CTX_load_verify_locations(ctx, ca_cert.file_name, NULL) != 1) {
389 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
390 ERR_error_string(ERR_get_error(), NULL));
393 VLOG_INFO("killing successful connection to retry using CA cert");
398 ssl_connect(struct stream *stream)
400 struct ssl_stream *sslv = ssl_stream_cast(stream);
403 switch (sslv->state) {
404 case STATE_TCP_CONNECTING:
405 retval = check_connection_completion(sslv->fd);
409 sslv->state = STATE_SSL_CONNECTING;
412 case STATE_SSL_CONNECTING:
413 retval = (sslv->type == CLIENT
414 ? SSL_connect(sslv->ssl) : SSL_accept(sslv->ssl));
416 int error = SSL_get_error(sslv->ssl, retval);
417 if (retval < 0 && ssl_wants_io(error)) {
421 interpret_ssl_error((sslv->type == CLIENT ? "SSL_connect"
422 : "SSL_accept"), retval, error, &unused);
423 shutdown(sslv->fd, SHUT_RDWR);
426 } else if (bootstrap_ca_cert) {
427 return do_ca_cert_bootstrap(stream);
428 } else if ((SSL_get_verify_mode(sslv->ssl)
429 & (SSL_VERIFY_NONE | SSL_VERIFY_PEER))
430 != SSL_VERIFY_PEER) {
431 /* Two or more SSL connections completed at the same time while we
432 * were in bootstrap mode. Only one of these can finish the
433 * bootstrap successfully. The other one(s) must be rejected
434 * because they were not verified against the bootstrapped CA
435 * certificate. (Alternatively we could verify them against the CA
436 * certificate, but that's more trouble than it's worth. These
437 * connections will succeed the next time they retry, assuming that
438 * they have a certificate against the correct CA.) */
439 VLOG_ERR("rejecting SSL connection during bootstrap race window");
450 ssl_close(struct stream *stream)
452 struct ssl_stream *sslv = ssl_stream_cast(stream);
453 ssl_clear_txbuf(sslv);
455 /* Attempt clean shutdown of the SSL connection. This will work most of
456 * the time, as long as the kernel send buffer has some free space and the
457 * SSL connection isn't renegotiating, etc. That has to be good enough,
458 * since we don't have any way to continue the close operation in the
460 SSL_shutdown(sslv->ssl);
468 interpret_ssl_error(const char *function, int ret, int error,
475 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_NONE", function);
478 case SSL_ERROR_ZERO_RETURN:
479 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_ZERO_RETURN", function);
482 case SSL_ERROR_WANT_READ:
486 case SSL_ERROR_WANT_WRITE:
490 case SSL_ERROR_WANT_CONNECT:
491 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_CONNECT", function);
494 case SSL_ERROR_WANT_ACCEPT:
495 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_ACCEPT", function);
498 case SSL_ERROR_WANT_X509_LOOKUP:
499 VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_X509_LOOKUP",
503 case SSL_ERROR_SYSCALL: {
504 int queued_error = ERR_get_error();
505 if (queued_error == 0) {
508 VLOG_WARN_RL(&rl, "%s: system error (%s)",
509 function, strerror(status));
512 VLOG_WARN_RL(&rl, "%s: unexpected SSL connection close",
517 VLOG_WARN_RL(&rl, "%s: %s",
518 function, ERR_error_string(queued_error, NULL));
523 case SSL_ERROR_SSL: {
524 int queued_error = ERR_get_error();
525 if (queued_error != 0) {
526 VLOG_WARN_RL(&rl, "%s: %s",
527 function, ERR_error_string(queued_error, NULL));
529 VLOG_ERR_RL(&rl, "%s: SSL_ERROR_SSL without queued error",
536 VLOG_ERR_RL(&rl, "%s: bad SSL error code %d", function, error);
543 ssl_recv(struct stream *stream, void *buffer, size_t n)
545 struct ssl_stream *sslv = ssl_stream_cast(stream);
549 /* Behavior of zero-byte SSL_read is poorly defined. */
552 old_state = SSL_get_state(sslv->ssl);
553 ret = SSL_read(sslv->ssl, buffer, n);
554 if (old_state != SSL_get_state(sslv->ssl)) {
555 sslv->tx_want = SSL_NOTHING;
557 sslv->rx_want = SSL_NOTHING;
562 int error = SSL_get_error(sslv->ssl, ret);
563 if (error == SSL_ERROR_ZERO_RETURN) {
566 return -interpret_ssl_error("SSL_read", ret, error,
573 ssl_clear_txbuf(struct ssl_stream *sslv)
575 ofpbuf_delete(sslv->txbuf);
580 ssl_do_tx(struct stream *stream)
582 struct ssl_stream *sslv = ssl_stream_cast(stream);
585 int old_state = SSL_get_state(sslv->ssl);
586 int ret = SSL_write(sslv->ssl, sslv->txbuf->data, sslv->txbuf->size);
587 if (old_state != SSL_get_state(sslv->ssl)) {
588 sslv->rx_want = SSL_NOTHING;
590 sslv->tx_want = SSL_NOTHING;
592 ofpbuf_pull(sslv->txbuf, ret);
593 if (sslv->txbuf->size == 0) {
597 int ssl_error = SSL_get_error(sslv->ssl, ret);
598 if (ssl_error == SSL_ERROR_ZERO_RETURN) {
599 VLOG_WARN_RL(&rl, "SSL_write: connection closed");
602 return interpret_ssl_error("SSL_write", ret, ssl_error,
610 ssl_send(struct stream *stream, const void *buffer, size_t n)
612 struct ssl_stream *sslv = ssl_stream_cast(stream);
619 sslv->txbuf = ofpbuf_clone_data(buffer, n);
620 error = ssl_do_tx(stream);
623 ssl_clear_txbuf(sslv);
626 leak_checker_claim(buffer);
636 ssl_run(struct stream *stream)
638 struct ssl_stream *sslv = ssl_stream_cast(stream);
640 if (sslv->txbuf && ssl_do_tx(stream) != EAGAIN) {
641 ssl_clear_txbuf(sslv);
646 ssl_run_wait(struct stream *stream)
648 struct ssl_stream *sslv = ssl_stream_cast(stream);
650 if (sslv->tx_want != SSL_NOTHING) {
651 poll_fd_wait(sslv->fd, want_to_poll_events(sslv->tx_want));
656 ssl_wait(struct stream *stream, enum stream_wait_type wait)
658 struct ssl_stream *sslv = ssl_stream_cast(stream);
662 if (stream_connect(stream) != EAGAIN) {
663 poll_immediate_wake();
665 switch (sslv->state) {
666 case STATE_TCP_CONNECTING:
667 poll_fd_wait(sslv->fd, POLLOUT);
670 case STATE_SSL_CONNECTING:
671 /* ssl_connect() called SSL_accept() or SSL_connect(), which
672 * set up the status that we test here. */
673 poll_fd_wait(sslv->fd,
674 want_to_poll_events(SSL_want(sslv->ssl)));
684 if (sslv->rx_want != SSL_NOTHING) {
685 poll_fd_wait(sslv->fd, want_to_poll_events(sslv->rx_want));
687 poll_immediate_wake();
693 /* We have room in our tx queue. */
694 poll_immediate_wake();
696 /* stream_run_wait() will do the right thing; don't bother with
706 struct stream_class ssl_stream_class = {
709 ssl_close, /* close */
710 ssl_connect, /* connect */
714 ssl_run_wait, /* run_wait */
722 struct pstream pstream;
726 struct pstream_class pssl_pstream_class;
728 static struct pssl_pstream *
729 pssl_pstream_cast(struct pstream *pstream)
731 pstream_assert_class(pstream, &pssl_pstream_class);
732 return CONTAINER_OF(pstream, struct pssl_pstream, pstream);
736 pssl_open(const char *name OVS_UNUSED, char *suffix, struct pstream **pstreamp)
738 struct pssl_pstream *pssl;
739 struct sockaddr_in sin;
740 char bound_name[128];
749 fd = inet_open_passive(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin);
753 sprintf(bound_name, "pssl:%"PRIu16":"IP_FMT,
754 ntohs(sin.sin_port), IP_ARGS(&sin.sin_addr.s_addr));
756 pssl = xmalloc(sizeof *pssl);
757 pstream_init(&pssl->pstream, &pssl_pstream_class, bound_name);
759 *pstreamp = &pssl->pstream;
764 pssl_close(struct pstream *pstream)
766 struct pssl_pstream *pssl = pssl_pstream_cast(pstream);
772 pssl_accept(struct pstream *pstream, struct stream **new_streamp)
774 struct pssl_pstream *pssl = pssl_pstream_cast(pstream);
775 struct sockaddr_in sin;
776 socklen_t sin_len = sizeof sin;
781 new_fd = accept(pssl->fd, &sin, &sin_len);
784 if (error != EAGAIN) {
785 VLOG_DBG_RL(&rl, "accept: %s", strerror(error));
790 error = set_nonblocking(new_fd);
796 sprintf(name, "ssl:"IP_FMT, IP_ARGS(&sin.sin_addr));
797 if (sin.sin_port != htons(OFP_SSL_PORT)) {
798 sprintf(strchr(name, '\0'), ":%"PRIu16, ntohs(sin.sin_port));
800 return new_ssl_stream(name, new_fd, SERVER, STATE_SSL_CONNECTING, &sin,
805 pssl_wait(struct pstream *pstream)
807 struct pssl_pstream *pssl = pssl_pstream_cast(pstream);
808 poll_fd_wait(pssl->fd, POLLIN);
811 struct pstream_class pssl_pstream_class = {
820 * Returns true if OpenSSL error is WANT_READ or WANT_WRITE, indicating that
821 * OpenSSL is requesting that we call it back when the socket is ready for read
822 * or writing, respectively.
825 ssl_wants_io(int ssl_error)
827 return (ssl_error == SSL_ERROR_WANT_WRITE
828 || ssl_error == SSL_ERROR_WANT_READ);
834 static int init_status = -1;
835 if (init_status < 0) {
836 init_status = do_ssl_init();
837 assert(init_status >= 0);
848 SSL_load_error_strings();
850 method = TLSv1_method();
851 if (method == NULL) {
852 VLOG_ERR("TLSv1_method: %s", ERR_error_string(ERR_get_error(), NULL));
856 ctx = SSL_CTX_new(method);
858 VLOG_ERR("SSL_CTX_new: %s", ERR_error_string(ERR_get_error(), NULL));
861 SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
862 SSL_CTX_set_tmp_dh_callback(ctx, tmp_dh_callback);
863 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
864 SSL_CTX_set_mode(ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
865 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
872 tmp_dh_callback(SSL *ssl OVS_UNUSED, int is_export OVS_UNUSED, int keylength)
877 DH *(*constructor)(void);
880 static struct dh dh_table[] = {
881 {1024, NULL, get_dh1024},
882 {2048, NULL, get_dh2048},
883 {4096, NULL, get_dh4096},
888 for (dh = dh_table; dh < &dh_table[ARRAY_SIZE(dh_table)]; dh++) {
889 if (dh->keylength == keylength) {
891 dh->dh = dh->constructor();
893 ovs_fatal(ENOMEM, "out of memory constructing "
894 "Diffie-Hellman parameters");
900 VLOG_ERR_RL(&rl, "no Diffie-Hellman parameters for key length %d",
905 /* Returns true if SSL is at least partially configured. */
907 stream_ssl_is_configured(void)
909 return private_key.file_name || certificate.file_name || ca_cert.file_name;
913 get_mtime(const char *file_name, struct timespec *mtime)
917 if (!stat(file_name, &s)) {
918 mtime->tv_sec = s.st_mtime;
920 #if HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC
921 mtime->tv_nsec = s.st_mtim.tv_nsec;
922 #elif HAVE_STRUCT_STAT_ST_MTIMENSEC
923 mtime->tv_nsec = s.st_mtimensec;
928 mtime->tv_sec = mtime->tv_nsec = 0;
933 update_ssl_config(struct ssl_config_file *config, const char *file_name)
935 struct timespec mtime;
937 if (ssl_init() || !file_name) {
941 /* If the file name hasn't changed and neither has the file contents, stop
943 get_mtime(file_name, &mtime);
944 if (config->file_name
945 && !strcmp(config->file_name, file_name)
946 && mtime.tv_sec == config->mtime.tv_sec
947 && mtime.tv_nsec == config->mtime.tv_nsec) {
951 config->mtime = mtime;
952 free(config->file_name);
953 config->file_name = xstrdup(file_name);
958 stream_ssl_set_private_key_file(const char *file_name)
960 if (!update_ssl_config(&private_key, file_name)) {
963 if (SSL_CTX_use_PrivateKey_file(ctx, file_name, SSL_FILETYPE_PEM) != 1) {
964 VLOG_ERR("SSL_use_PrivateKey_file: %s",
965 ERR_error_string(ERR_get_error(), NULL));
968 private_key.read = true;
972 stream_ssl_set_certificate_file(const char *file_name)
974 if (!update_ssl_config(&certificate, file_name)) {
977 if (SSL_CTX_use_certificate_chain_file(ctx, file_name) != 1) {
978 VLOG_ERR("SSL_use_certificate_file: %s",
979 ERR_error_string(ERR_get_error(), NULL));
982 certificate.read = true;
985 /* Reads the X509 certificate or certificates in file 'file_name'. On success,
986 * stores the address of the first element in an array of pointers to
987 * certificates in '*certs' and the number of certificates in the array in
988 * '*n_certs', and returns 0. On failure, stores a null pointer in '*certs', 0
989 * in '*n_certs', and returns a positive errno value.
991 * The caller is responsible for freeing '*certs'. */
993 read_cert_file(const char *file_name, X509 ***certs, size_t *n_certs)
996 size_t allocated_certs = 0;
1001 file = fopen(file_name, "r");
1003 VLOG_ERR("failed to open %s for reading: %s",
1004 file_name, strerror(errno));
1012 /* Read certificate from file. */
1013 certificate = PEM_read_X509(file, NULL, NULL, NULL);
1017 VLOG_ERR("PEM_read_X509 failed reading %s: %s",
1018 file_name, ERR_error_string(ERR_get_error(), NULL));
1019 for (i = 0; i < *n_certs; i++) {
1020 X509_free((*certs)[i]);
1028 /* Add certificate to array. */
1029 if (*n_certs >= allocated_certs) {
1030 *certs = x2nrealloc(*certs, &allocated_certs, sizeof **certs);
1032 (*certs)[(*n_certs)++] = certificate;
1034 /* Are there additional certificates in the file? */
1037 } while (isspace(c));
1048 /* Sets 'file_name' as the name of a file containing one or more X509
1049 * certificates to send to the peer. Typical use in OpenFlow is to send the CA
1050 * certificate to the peer, which enables a switch to pick up the controller's
1051 * CA certificate on its first connection. */
1053 stream_ssl_set_peer_ca_cert_file(const char *file_name)
1063 if (!read_cert_file(file_name, &certs, &n_certs)) {
1064 for (i = 0; i < n_certs; i++) {
1065 if (SSL_CTX_add_extra_chain_cert(ctx, certs[i]) != 1) {
1066 VLOG_ERR("SSL_CTX_add_extra_chain_cert: %s",
1067 ERR_error_string(ERR_get_error(), NULL));
1074 /* Logs fingerprint of CA certificate 'cert' obtained from 'file_name'. */
1076 log_ca_cert(const char *file_name, X509 *cert)
1078 unsigned char digest[EVP_MAX_MD_SIZE];
1079 unsigned int n_bytes;
1084 if (!X509_digest(cert, EVP_sha1(), digest, &n_bytes)) {
1085 ds_put_cstr(&fp, "<out of memory>");
1088 for (i = 0; i < n_bytes; i++) {
1090 ds_put_char(&fp, ':');
1092 ds_put_format(&fp, "%02hhx", digest[i]);
1095 subject = X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0);
1096 VLOG_INFO("Trusting CA cert from %s (%s) (fingerprint %s)", file_name,
1097 subject ? subject : "<out of memory>", ds_cstr(&fp));
1103 stream_ssl_set_ca_cert_file__(const char *file_name, bool bootstrap)
1109 if (bootstrap && stat(file_name, &s) && errno == ENOENT) {
1110 bootstrap_ca_cert = true;
1111 } else if (!read_cert_file(file_name, &certs, &n_certs)) {
1114 /* Set up list of CAs that the server will accept from the client. */
1115 for (i = 0; i < n_certs; i++) {
1116 /* SSL_CTX_add_client_CA makes a copy of the relevant data. */
1117 if (SSL_CTX_add_client_CA(ctx, certs[i]) != 1) {
1118 VLOG_ERR("failed to add client certificate %d from %s: %s",
1120 ERR_error_string(ERR_get_error(), NULL));
1122 log_ca_cert(file_name, certs[i]);
1124 X509_free(certs[i]);
1128 /* Set up CAs for OpenSSL to trust in verifying the peer's
1130 if (SSL_CTX_load_verify_locations(ctx, file_name, NULL) != 1) {
1131 VLOG_ERR("SSL_CTX_load_verify_locations: %s",
1132 ERR_error_string(ERR_get_error(), NULL));
1136 bootstrap_ca_cert = false;
1138 ca_cert.read = true;
1141 /* Sets 'file_name' as the name of the file from which to read the CA
1142 * certificate used to verify the peer within SSL connections. If 'bootstrap'
1143 * is false, the file must exist. If 'bootstrap' is false, then the file is
1144 * read if it is exists; if it does not, then it will be created from the CA
1145 * certificate received from the peer on the first SSL connection. */
1147 stream_ssl_set_ca_cert_file(const char *file_name, bool bootstrap)
1149 if (!update_ssl_config(&ca_cert, file_name)) {
1153 stream_ssl_set_ca_cert_file__(file_name, bootstrap);