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204366af963af710ec78b1ae0ec4d4129a49aa7b
openflow/lib/vconn-ssl.c
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/* Copyright (c) 2008, 2009 The Board of Trustees of The Leland Stanford
* Junior University
*
* We are making the OpenFlow specification and associated documentation
* (Software) available for public use and benefit with the expectation
* that others will use, modify and enhance the Software and contribute
* those enhancements back to the community. However, since we would
* like to make the Software available for broadest use, with as few
* restrictions as possible permission is hereby granted, free of
* charge, to any person obtaining a copy of this Software to deal in
* the Software under the copyrights without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* The name and trademarks of copyright holder(s) may NOT be used in
* advertising or publicity pertaining to the Software or any
* derivatives without specific, written prior permission.
*/
#include <config.h>
#include "vconn-ssl.h"
#include "dhparams.h"
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <inttypes.h>
#include <string.h>
#include <netinet/tcp.h>
#include <openssl/err.h>
#include <openssl/ssl.h>
#include <openssl/x509v3.h>
#include <poll.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
#include "dynamic-string.h"
#include "leak-checker.h"
#include "ofpbuf.h"
#include "openflow/openflow.h"
#include "packets.h"
#include "poll-loop.h"
#include "socket-util.h"
#include "socket-util.h"
#include "util.h"
#include "vconn-provider.h"
#include "vconn.h"
#include "vlog.h"
#define THIS_MODULE VLM_vconn_ssl
/* Active SSL. */
enum ssl_state {
STATE_TCP_CONNECTING,
STATE_SSL_CONNECTING
};
enum session_type {
CLIENT,
SERVER
};
struct ssl_vconn
{
struct vconn vconn;
enum ssl_state state;
int connect_error;
enum session_type type;
int fd;
SSL *ssl;
struct ofpbuf *rxbuf;
struct ofpbuf *txbuf;
struct poll_waiter *tx_waiter;
/* rx_want and tx_want record the result of the last call to SSL_read()
* and SSL_write(), respectively:
*
* - If the call reported that data needed to be read from the file
* descriptor, the corresponding member is set to SSL_READING.
*
* - If the call reported that data needed to be written to the file
* descriptor, the corresponding member is set to SSL_WRITING.
*
* - Otherwise, the member is set to SSL_NOTHING, indicating that the
* call completed successfully (or with an error) and that there is no
* need to block.
*
* These are needed because there is no way to ask OpenSSL what a data read
* or write would require without giving it a buffer to receive into or
* data to send, respectively. (Note that the SSL_want() status is
* overwritten by each SSL_read() or SSL_write() call, so we can't rely on
* its value.)
*
* A single call to SSL_read() or SSL_write() can perform both reading
* and writing and thus invalidate not one of these values but actually
* both. Consider this situation, for example:
*
* - SSL_write() blocks on a read, so tx_want gets SSL_READING.
*
* - SSL_read() laters succeeds reading from 'fd' and clears out the
* whole receive buffer, so rx_want gets SSL_READING.
*
* - Client calls vconn_wait(WAIT_RECV) and vconn_wait(WAIT_SEND) and
* blocks.
*
* - Now we're stuck blocking until the peer sends us data, even though
* SSL_write() could now succeed, which could easily be a deadlock
* condition.
*
* On the other hand, we can't reset both tx_want and rx_want on every call
* to SSL_read() or SSL_write(), because that would produce livelock,
* e.g. in this situation:
*
* - SSL_write() blocks, so tx_want gets SSL_READING or SSL_WRITING.
*
* - SSL_read() blocks, so rx_want gets SSL_READING or SSL_WRITING,
* but tx_want gets reset to SSL_NOTHING.
*
* - Client calls vconn_wait(WAIT_RECV) and vconn_wait(WAIT_SEND) and
* blocks.
*
* - Client wakes up immediately since SSL_NOTHING in tx_want indicates
* that no blocking is necessary.
*
* The solution we adopt here is to set tx_want to SSL_NOTHING after
* calling SSL_read() only if the SSL state of the connection changed,
* which indicates that an SSL-level renegotiation made some progress, and
* similarly for rx_want and SSL_write(). This prevents both the
* deadlock and livelock situations above.
*/
int rx_want, tx_want;
};
/* SSL context created by ssl_init(). */
static SSL_CTX *ctx;
/* Required configuration. */
static bool has_private_key, has_certificate, has_ca_cert;
/* Ordinarily, we require a CA certificate for the peer to be locally
* available. 'has_ca_cert' is true when this is the case, and neither of the
* following variables matter.
*
* We can, however, bootstrap the CA certificate from the peer at the beginning
* of our first connection then use that certificate on all subsequent
* connections, saving it to a file for use in future runs also. In this case,
* 'has_ca_cert' is false, 'bootstrap_ca_cert' is true, and 'ca_cert_file'
* names the file to be saved. */
static bool bootstrap_ca_cert;
static char *ca_cert_file;
/* Who knows what can trigger various SSL errors, so let's throttle them down
* quite a bit. */
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 25);
static int ssl_init(void);
static int do_ssl_init(void);
static bool ssl_wants_io(int ssl_error);
static void ssl_close(struct vconn *);
static void ssl_clear_txbuf(struct ssl_vconn *);
static int interpret_ssl_error(const char *function, int ret, int error,
int *want);
static void ssl_tx_poll_callback(int fd, short int revents, void *vconn_);
static DH *tmp_dh_callback(SSL *ssl, int is_export UNUSED, int keylength);
static void log_ca_cert(const char *file_name, X509 *cert);
static short int
want_to_poll_events(int want)
{
switch (want) {
case SSL_NOTHING:
NOT_REACHED();
case SSL_READING:
return POLLIN;
case SSL_WRITING:
return POLLOUT;
default:
NOT_REACHED();
}
}
static int
new_ssl_vconn(const char *name, int fd, enum session_type type,
enum ssl_state state, const struct sockaddr_in *sin,
struct vconn **vconnp)
{
struct ssl_vconn *sslv;
SSL *ssl = NULL;
int on = 1;
int retval;
/* Check for all the needful configuration. */
if (!has_private_key) {
VLOG_ERR("Private key must be configured to use SSL");
goto error;
}
if (!has_certificate) {
VLOG_ERR("Certificate must be configured to use SSL");
goto error;
}
if (!has_ca_cert && !bootstrap_ca_cert) {
VLOG_ERR("CA certificate must be configured to use SSL");
goto error;
}
if (!SSL_CTX_check_private_key(ctx)) {
VLOG_ERR("Private key does not match certificate public key: %s",
ERR_error_string(ERR_get_error(), NULL));
goto error;
}
/* Disable Nagle. */
retval = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof on);
if (retval) {
VLOG_ERR("%s: setsockopt(TCP_NODELAY): %s", name, strerror(errno));
close(fd);
return errno;
}
/* Create and configure OpenSSL stream. */
ssl = SSL_new(ctx);
if (ssl == NULL) {
VLOG_ERR("SSL_new: %s", ERR_error_string(ERR_get_error(), NULL));
close(fd);
return ENOPROTOOPT;
}
if (SSL_set_fd(ssl, fd) == 0) {
VLOG_ERR("SSL_set_fd: %s", ERR_error_string(ERR_get_error(), NULL));
goto error;
}
if (bootstrap_ca_cert && type == CLIENT) {
SSL_set_verify(ssl, SSL_VERIFY_NONE, NULL);
}
/* Create and return the ssl_vconn. */
sslv = xmalloc(sizeof *sslv);
vconn_init(&sslv->vconn, &ssl_vconn_class, EAGAIN, sin->sin_addr.s_addr,
name, true);
sslv->state = state;
sslv->type = type;
sslv->fd = fd;
sslv->ssl = ssl;
sslv->rxbuf = NULL;
sslv->txbuf = NULL;
sslv->tx_waiter = NULL;
sslv->rx_want = sslv->tx_want = SSL_NOTHING;
*vconnp = &sslv->vconn;
return 0;
error:
if (ssl) {
SSL_free(ssl);
}
close(fd);
return ENOPROTOOPT;
}
static struct ssl_vconn *
ssl_vconn_cast(struct vconn *vconn)
{
vconn_assert_class(vconn, &ssl_vconn_class);
return CONTAINER_OF(vconn, struct ssl_vconn, vconn);
}
static int
ssl_open(const char *name, char *suffix, struct vconn **vconnp)
{
char *save_ptr, *host_name, *port_string;
struct sockaddr_in sin;
int retval;
int fd;
retval = ssl_init();
if (retval) {
return retval;
}
/* Glibc 2.7 has a bug in strtok_r when compiling with optimization that
* can cause segfaults here:
* http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
* Using "::" instead of the obvious ":" works around it. */
host_name = strtok_r(suffix, "::", &save_ptr);
port_string = strtok_r(NULL, "::", &save_ptr);
if (!host_name) {
ofp_error(0, "%s: bad peer name format", name);
return EAFNOSUPPORT;
}
memset(&sin, 0, sizeof sin);
sin.sin_family = AF_INET;
if (lookup_ip(host_name, &sin.sin_addr)) {
return ENOENT;
}
sin.sin_port = htons(port_string && *port_string ? atoi(port_string)
: OFP_SSL_PORT);
/* Create socket. */
fd = socket(AF_INET, SOCK_STREAM, 0);
if (fd < 0) {
VLOG_ERR("%s: socket: %s", name, strerror(errno));
return errno;
}
retval = set_nonblocking(fd);
if (retval) {
close(fd);
return retval;
}
/* Connect socket. */
retval = connect(fd, (struct sockaddr *) &sin, sizeof sin);
if (retval < 0) {
if (errno == EINPROGRESS) {
return new_ssl_vconn(name, fd, CLIENT, STATE_TCP_CONNECTING,
&sin, vconnp);
} else {
int error = errno;
VLOG_ERR("%s: connect: %s", name, strerror(error));
close(fd);
return error;
}
} else {
return new_ssl_vconn(name, fd, CLIENT, STATE_SSL_CONNECTING,
&sin, vconnp);
}
}
static int
do_ca_cert_bootstrap(struct vconn *vconn)
{
struct ssl_vconn *sslv = ssl_vconn_cast(vconn);
STACK_OF(X509) *chain;
X509 *ca_cert;
FILE *file;
int error;
int fd;
chain = SSL_get_peer_cert_chain(sslv->ssl);
if (!chain || !sk_X509_num(chain)) {
VLOG_ERR("could not bootstrap CA cert: no certificate presented by "
"peer");
return EPROTO;
}
ca_cert = sk_X509_value(chain, sk_X509_num(chain) - 1);
/* Check that 'ca_cert' is self-signed. Otherwise it is not a CA
* certificate and we should not attempt to use it as one. */
error = X509_check_issued(ca_cert, ca_cert);
if (error) {
VLOG_ERR("could not bootstrap CA cert: obtained certificate is "
"not self-signed (%s)",
X509_verify_cert_error_string(error));
if (sk_X509_num(chain) < 2) {
VLOG_ERR("only one certificate was received, so probably the peer "
"is not configured to send its CA certificate");
}
return EPROTO;
}
fd = open(ca_cert_file, O_CREAT | O_EXCL | O_WRONLY, 0444);
if (fd < 0) {
VLOG_ERR("could not bootstrap CA cert: creating %s failed: %s",
ca_cert_file, strerror(errno));
return errno;
}
file = fdopen(fd, "w");
if (!file) {
int error = errno;
VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s",
strerror(error));
unlink(ca_cert_file);
return error;
}
if (!PEM_write_X509(file, ca_cert)) {
VLOG_ERR("could not bootstrap CA cert: PEM_write_X509 to %s failed: "
"%s", ca_cert_file, ERR_error_string(ERR_get_error(), NULL));
fclose(file);
unlink(ca_cert_file);
return EIO;
}
if (fclose(file)) {
int error = errno;
VLOG_ERR("could not bootstrap CA cert: writing %s failed: %s",
ca_cert_file, strerror(error));
unlink(ca_cert_file);
return error;
}
VLOG_INFO("successfully bootstrapped CA cert to %s", ca_cert_file);
log_ca_cert(ca_cert_file, ca_cert);
bootstrap_ca_cert = false;
has_ca_cert = true;
/* SSL_CTX_add_client_CA makes a copy of ca_cert's relevant data. */
SSL_CTX_add_client_CA(ctx, ca_cert);
/* SSL_CTX_use_certificate() takes ownership of the certificate passed in.
* 'ca_cert' is owned by sslv->ssl, so we need to duplicate it. */
ca_cert = X509_dup(ca_cert);
if (!ca_cert) {
out_of_memory();
}
if (SSL_CTX_load_verify_locations(ctx, ca_cert_file, NULL) != 1) {
VLOG_ERR("SSL_CTX_load_verify_locations: %s",
ERR_error_string(ERR_get_error(), NULL));
return EPROTO;
}
VLOG_INFO("killing successful connection to retry using CA cert");
return EPROTO;
}
static int
ssl_connect(struct vconn *vconn)
{
struct ssl_vconn *sslv = ssl_vconn_cast(vconn);
int retval;
switch (sslv->state) {
case STATE_TCP_CONNECTING:
retval = check_connection_completion(sslv->fd);
if (retval) {
return retval;
}
sslv->state = STATE_SSL_CONNECTING;
/* Fall through. */
case STATE_SSL_CONNECTING:
retval = (sslv->type == CLIENT
? SSL_connect(sslv->ssl) : SSL_accept(sslv->ssl));
if (retval != 1) {
int error = SSL_get_error(sslv->ssl, retval);
if (retval < 0 && ssl_wants_io(error)) {
return EAGAIN;
} else {
int unused;
interpret_ssl_error((sslv->type == CLIENT ? "SSL_connect"
: "SSL_accept"), retval, error, &unused);
shutdown(sslv->fd, SHUT_RDWR);
return EPROTO;
}
} else if (bootstrap_ca_cert) {
return do_ca_cert_bootstrap(vconn);
} else if ((SSL_get_verify_mode(sslv->ssl)
& (SSL_VERIFY_NONE | SSL_VERIFY_PEER))
!= SSL_VERIFY_PEER) {
/* Two or more SSL connections completed at the same time while we
* were in bootstrap mode. Only one of these can finish the
* bootstrap successfully. The other one(s) must be rejected
* because they were not verified against the bootstrapped CA
* certificate. (Alternatively we could verify them against the CA
* certificate, but that's more trouble than it's worth. These
* connections will succeed the next time they retry, assuming that
* they have a certificate against the correct CA.) */
VLOG_ERR("rejecting SSL connection during bootstrap race window");
return EPROTO;
} else {
return 0;
}
}
NOT_REACHED();
}
static void
ssl_close(struct vconn *vconn)
{
struct ssl_vconn *sslv = ssl_vconn_cast(vconn);
poll_cancel(sslv->tx_waiter);
ssl_clear_txbuf(sslv);
ofpbuf_delete(sslv->rxbuf);
SSL_free(sslv->ssl);
close(sslv->fd);
free(sslv);
}
static int
interpret_ssl_error(const char *function, int ret, int error,
int *want)
{
*want = SSL_NOTHING;
switch (error) {
case SSL_ERROR_NONE:
VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_NONE", function);
break;
case SSL_ERROR_ZERO_RETURN:
VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_ZERO_RETURN", function);
break;
case SSL_ERROR_WANT_READ:
*want = SSL_READING;
return EAGAIN;
case SSL_ERROR_WANT_WRITE:
*want = SSL_WRITING;
return EAGAIN;
case SSL_ERROR_WANT_CONNECT:
VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_CONNECT", function);
break;
case SSL_ERROR_WANT_ACCEPT:
VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_ACCEPT", function);
break;
case SSL_ERROR_WANT_X509_LOOKUP:
VLOG_ERR_RL(&rl, "%s: unexpected SSL_ERROR_WANT_X509_LOOKUP",
function);
break;
case SSL_ERROR_SYSCALL: {
int queued_error = ERR_get_error();
if (queued_error == 0) {
if (ret < 0) {
int status = errno;
VLOG_WARN_RL(&rl, "%s: system error (%s)",
function, strerror(status));
return status;
} else {
VLOG_WARN_RL(&rl, "%s: unexpected SSL connection close",
function);
return EPROTO;
}
} else {
VLOG_WARN_RL(&rl, "%s: %s",
function, ERR_error_string(queued_error, NULL));
break;
}
}
case SSL_ERROR_SSL: {
int queued_error = ERR_get_error();
if (queued_error != 0) {
VLOG_WARN_RL(&rl, "%s: %s",
function, ERR_error_string(queued_error, NULL));
} else {
VLOG_ERR_RL(&rl, "%s: SSL_ERROR_SSL without queued error",
function);
}
break;
}
default:
VLOG_ERR_RL(&rl, "%s: bad SSL error code %d", function, error);
break;
}
return EIO;
}
static int
ssl_recv(struct vconn *vconn, struct ofpbuf **bufferp)
{
struct ssl_vconn *sslv = ssl_vconn_cast(vconn);
struct ofpbuf *rx;
size_t want_bytes;
int old_state;
ssize_t ret;
if (sslv->rxbuf == NULL) {
sslv->rxbuf = ofpbuf_new(1564);
}
rx = sslv->rxbuf;
again:
if (sizeof(struct ofp_header) > rx->size) {
want_bytes = sizeof(struct ofp_header) - rx->size;
} else {
struct ofp_header *oh = rx->data;
size_t length = ntohs(oh->length);
if (length < sizeof(struct ofp_header)) {
VLOG_ERR_RL(&rl, "received too-short ofp_header (%zu bytes)",
length);
return EPROTO;
}
want_bytes = length - rx->size;
if (!want_bytes) {
*bufferp = rx;
sslv->rxbuf = NULL;
return 0;
}
}
ofpbuf_prealloc_tailroom(rx, want_bytes);
/* Behavior of zero-byte SSL_read is poorly defined. */
assert(want_bytes > 0);
old_state = SSL_get_state(sslv->ssl);
ret = SSL_read(sslv->ssl, ofpbuf_tail(rx), want_bytes);
if (old_state != SSL_get_state(sslv->ssl)) {
sslv->tx_want = SSL_NOTHING;
if (sslv->tx_waiter) {
poll_cancel(sslv->tx_waiter);
ssl_tx_poll_callback(sslv->fd, POLLIN, vconn);
}
}
sslv->rx_want = SSL_NOTHING;
if (ret > 0) {
rx->size += ret;
if (ret == want_bytes) {
if (rx->size > sizeof(struct ofp_header)) {
*bufferp = rx;
sslv->rxbuf = NULL;
return 0;
} else {
goto again;
}
}
return EAGAIN;
} else {
int error = SSL_get_error(sslv->ssl, ret);
if (error == SSL_ERROR_ZERO_RETURN) {
/* Connection closed (EOF). */
if (rx->size) {
VLOG_WARN_RL(&rl, "SSL_read: unexpected connection close");
return EPROTO;
} else {
return EOF;
}
} else {
return interpret_ssl_error("SSL_read", ret, error, &sslv->rx_want);
}
}
}
static void
ssl_clear_txbuf(struct ssl_vconn *sslv)
{
ofpbuf_delete(sslv->txbuf);
sslv->txbuf = NULL;
sslv->tx_waiter = NULL;
}
static void
ssl_register_tx_waiter(struct vconn *vconn)
{
struct ssl_vconn *sslv = ssl_vconn_cast(vconn);
sslv->tx_waiter = poll_fd_callback(sslv->fd,
want_to_poll_events(sslv->tx_want),
ssl_tx_poll_callback, vconn);
}
static int
ssl_do_tx(struct vconn *vconn)
{
struct ssl_vconn *sslv = ssl_vconn_cast(vconn);
for (;;) {
int old_state = SSL_get_state(sslv->ssl);
int ret = SSL_write(sslv->ssl, sslv->txbuf->data, sslv->txbuf->size);
if (old_state != SSL_get_state(sslv->ssl)) {
sslv->rx_want = SSL_NOTHING;
}
sslv->tx_want = SSL_NOTHING;
if (ret > 0) {
ofpbuf_pull(sslv->txbuf, ret);
if (sslv->txbuf->size == 0) {
return 0;
}
} else {
int ssl_error = SSL_get_error(sslv->ssl, ret);
if (ssl_error == SSL_ERROR_ZERO_RETURN) {
VLOG_WARN_RL(&rl, "SSL_write: connection closed");
return EPIPE;
} else {
return interpret_ssl_error("SSL_write", ret, ssl_error,
&sslv->tx_want);
}
}
}
}
static void
ssl_tx_poll_callback(int fd UNUSED, short int revents UNUSED, void *vconn_)
{
struct vconn *vconn = vconn_;
struct ssl_vconn *sslv = ssl_vconn_cast(vconn);
int error = ssl_do_tx(vconn);
if (error != EAGAIN) {
ssl_clear_txbuf(sslv);
} else {
ssl_register_tx_waiter(vconn);
}
}
static int
ssl_send(struct vconn *vconn, struct ofpbuf *buffer)
{
struct ssl_vconn *sslv = ssl_vconn_cast(vconn);
if (sslv->txbuf) {
return EAGAIN;
} else {
int error;
sslv->txbuf = buffer;
error = ssl_do_tx(vconn);
switch (error) {
case 0:
ssl_clear_txbuf(sslv);
return 0;
case EAGAIN:
leak_checker_claim(buffer);
ssl_register_tx_waiter(vconn);
return 0;
default:
sslv->txbuf = NULL;
return error;
}
}
}
static void
ssl_wait(struct vconn *vconn, enum vconn_wait_type wait)
{
struct ssl_vconn *sslv = ssl_vconn_cast(vconn);
switch (wait) {
case WAIT_CONNECT:
if (vconn_connect(vconn) != EAGAIN) {
poll_immediate_wake();
} else {
switch (sslv->state) {
case STATE_TCP_CONNECTING:
poll_fd_wait(sslv->fd, POLLOUT);
break;
case STATE_SSL_CONNECTING:
/* ssl_connect() called SSL_accept() or SSL_connect(), which
* set up the status that we test here. */
poll_fd_wait(sslv->fd,
want_to_poll_events(SSL_want(sslv->ssl)));
break;
default:
NOT_REACHED();
}
}
break;
case WAIT_RECV:
if (sslv->rx_want != SSL_NOTHING) {
poll_fd_wait(sslv->fd, want_to_poll_events(sslv->rx_want));
} else {
poll_immediate_wake();
}
break;
case WAIT_SEND:
if (!sslv->txbuf) {
/* We have room in our tx queue. */
poll_immediate_wake();
} else {
/* The call to ssl_tx_poll_callback() will wake us up. */
}
break;
default:
NOT_REACHED();
}
}
struct vconn_class ssl_vconn_class = {
"ssl", /* name */
ssl_open, /* open */
ssl_close, /* close */
ssl_connect, /* connect */
ssl_recv, /* recv */
ssl_send, /* send */
ssl_wait, /* wait */
};
/* Passive SSL. */
struct pssl_pvconn
{
struct pvconn pvconn;
int fd;
};
struct pvconn_class pssl_pvconn_class;
static struct pssl_pvconn *
pssl_pvconn_cast(struct pvconn *pvconn)
{
pvconn_assert_class(pvconn, &pssl_pvconn_class);
return CONTAINER_OF(pvconn, struct pssl_pvconn, pvconn);
}
static int
pssl_open(const char *name, char *suffix, struct pvconn **pvconnp)
{
struct sockaddr_in sin;
struct pssl_pvconn *pssl;
int retval;
int fd;
unsigned int yes = 1;
retval = ssl_init();
if (retval) {
return retval;
}
/* Create socket. */
fd = socket(AF_INET, SOCK_STREAM, 0);
if (fd < 0) {
int error = errno;
VLOG_ERR("%s: socket: %s", name, strerror(error));
return error;
}
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes) < 0) {
int error = errno;
VLOG_ERR("%s: setsockopt(SO_REUSEADDR): %s", name, strerror(errno));
return error;
}
memset(&sin, 0, sizeof sin);
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = htonl(INADDR_ANY);
sin.sin_port = htons(atoi(suffix) ? atoi(suffix) : OFP_SSL_PORT);
retval = bind(fd, (struct sockaddr *) &sin, sizeof sin);
if (retval < 0) {
int error = errno;
VLOG_ERR("%s: bind: %s", name, strerror(error));
close(fd);
return error;
}
retval = listen(fd, 10);
if (retval < 0) {
int error = errno;
VLOG_ERR("%s: listen: %s", name, strerror(error));
close(fd);
return error;
}
retval = set_nonblocking(fd);
if (retval) {
close(fd);
return retval;
}
pssl = xmalloc(sizeof *pssl);
pvconn_init(&pssl->pvconn, &pssl_pvconn_class, name);
pssl->fd = fd;
*pvconnp = &pssl->pvconn;
return 0;
}
static void
pssl_close(struct pvconn *pvconn)
{
struct pssl_pvconn *pssl = pssl_pvconn_cast(pvconn);
close(pssl->fd);
free(pssl);
}
static int
pssl_accept(struct pvconn *pvconn, struct vconn **new_vconnp)
{
struct pssl_pvconn *pssl = pssl_pvconn_cast(pvconn);
struct sockaddr_in sin;
socklen_t sin_len = sizeof sin;
char name[128];
int new_fd;
int error;
new_fd = accept(pssl->fd, &sin, &sin_len);
if (new_fd < 0) {
int error = errno;
if (error != EAGAIN) {
VLOG_DBG_RL(&rl, "accept: %s", strerror(error));
}
return error;
}
error = set_nonblocking(new_fd);
if (error) {
close(new_fd);
return error;
}
sprintf(name, "ssl:"IP_FMT, IP_ARGS(&sin.sin_addr));
if (sin.sin_port != htons(OFP_SSL_PORT)) {
sprintf(strchr(name, '\0'), ":%"PRIu16, ntohs(sin.sin_port));
}
return new_ssl_vconn(name, new_fd, SERVER, STATE_SSL_CONNECTING, &sin,
new_vconnp);
}
static void
pssl_wait(struct pvconn *pvconn)
{
struct pssl_pvconn *pssl = pssl_pvconn_cast(pvconn);
poll_fd_wait(pssl->fd, POLLIN);
}
struct pvconn_class pssl_pvconn_class = {
"pssl",
pssl_open,
pssl_close,
pssl_accept,
pssl_wait,
};
/*
* Returns true if OpenSSL error is WANT_READ or WANT_WRITE, indicating that
* OpenSSL is requesting that we call it back when the socket is ready for read
* or writing, respectively.
*/
static bool
ssl_wants_io(int ssl_error)
{
return (ssl_error == SSL_ERROR_WANT_WRITE
|| ssl_error == SSL_ERROR_WANT_READ);
}
static int
ssl_init(void)
{
static int init_status = -1;
if (init_status < 0) {
init_status = do_ssl_init();
assert(init_status >= 0);
}
return init_status;
}
static int
do_ssl_init(void)
{
SSL_METHOD *method;
SSL_library_init();
SSL_load_error_strings();
method = TLSv1_method();
if (method == NULL) {
VLOG_ERR("TLSv1_method: %s", ERR_error_string(ERR_get_error(), NULL));
return ENOPROTOOPT;
}
ctx = SSL_CTX_new(method);
if (ctx == NULL) {
VLOG_ERR("SSL_CTX_new: %s", ERR_error_string(ERR_get_error(), NULL));
return ENOPROTOOPT;
}
SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
SSL_CTX_set_tmp_dh_callback(ctx, tmp_dh_callback);
SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
SSL_CTX_set_mode(ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
NULL);
return 0;
}
static DH *
tmp_dh_callback(SSL *ssl UNUSED, int is_export UNUSED, int keylength)
{
struct dh {
int keylength;
DH *dh;
DH *(*constructor)(void);
};
static struct dh dh_table[] = {
{1024, NULL, get_dh1024},
{2048, NULL, get_dh2048},
{4096, NULL, get_dh4096},
};
struct dh *dh;
for (dh = dh_table; dh < &dh_table[ARRAY_SIZE(dh_table)]; dh++) {
if (dh->keylength == keylength) {
if (!dh->dh) {
dh->dh = dh->constructor();
if (!dh->dh) {
ofp_fatal(ENOMEM, "out of memory constructing "
"Diffie-Hellman parameters");
}
}
return dh->dh;
}
}
VLOG_ERR_RL(&rl, "no Diffie-Hellman parameters for key length %d",
keylength);
return NULL;
}
/* Returns true if SSL is at least partially configured. */
bool
vconn_ssl_is_configured(void)
{
return has_private_key || has_certificate || has_ca_cert;
}
void
vconn_ssl_set_private_key_file(const char *file_name)
{
if (ssl_init()) {
return;
}
if (SSL_CTX_use_PrivateKey_file(ctx, file_name, SSL_FILETYPE_PEM) != 1) {
VLOG_ERR("SSL_use_PrivateKey_file: %s",
ERR_error_string(ERR_get_error(), NULL));
return;
}
has_private_key = true;
}
void
vconn_ssl_set_certificate_file(const char *file_name)
{
if (ssl_init()) {
return;
}
if (SSL_CTX_use_certificate_chain_file(ctx, file_name) != 1) {
VLOG_ERR("SSL_use_certificate_file: %s",
ERR_error_string(ERR_get_error(), NULL));
return;
}
has_certificate = true;
}
/* Reads the X509 certificate or certificates in file 'file_name'. On success,
* stores the address of the first element in an array of pointers to
* certificates in '*certs' and the number of certificates in the array in
* '*n_certs', and returns 0. On failure, stores a null pointer in '*certs', 0
* in '*n_certs', and returns a positive errno value.
*
* The caller is responsible for freeing '*certs'. */
static int
read_cert_file(const char *file_name, X509 ***certs, size_t *n_certs)
{
FILE *file;
size_t allocated_certs = 0;
*certs = NULL;
*n_certs = 0;
file = fopen(file_name, "r");
if (!file) {
VLOG_ERR("failed to open %s for reading: %s",
file_name, strerror(errno));
return errno;
}
for (;;) {
X509 *certificate;
int c;
/* Read certificate from file. */
certificate = PEM_read_X509(file, NULL, NULL, NULL);
if (!certificate) {
size_t i;
VLOG_ERR("PEM_read_X509 failed reading %s: %s",
file_name, ERR_error_string(ERR_get_error(), NULL));
for (i = 0; i < *n_certs; i++) {
X509_free((*certs)[i]);
}
free(*certs);
*certs = NULL;
*n_certs = 0;
return EIO;
}
/* Add certificate to array. */
if (*n_certs >= allocated_certs) {
*certs = x2nrealloc(*certs, &allocated_certs, sizeof **certs);
}
(*certs)[(*n_certs)++] = certificate;
/* Are there additional certificates in the file? */
do {
c = getc(file);
} while (isspace(c));
if (c == EOF) {
break;
}
ungetc(c, file);
}
fclose(file);
return 0;
}
/* Sets 'file_name' as the name of a file containing one or more X509
* certificates to send to the peer. Typical use in OpenFlow is to send the CA
* certificate to the peer, which enables a switch to pick up the controller's
* CA certificate on its first connection. */
void
vconn_ssl_set_peer_ca_cert_file(const char *file_name)
{
X509 **certs;
size_t n_certs;
size_t i;
if (ssl_init()) {
return;
}
if (!read_cert_file(file_name, &certs, &n_certs)) {
for (i = 0; i < n_certs; i++) {
if (SSL_CTX_add_extra_chain_cert(ctx, certs[i]) != 1) {
VLOG_ERR("SSL_CTX_add_extra_chain_cert: %s",
ERR_error_string(ERR_get_error(), NULL));
}
}
free(certs);
}
}
/* Logs fingerprint of CA certificate 'cert' obtained from 'file_name'. */
static void
log_ca_cert(const char *file_name, X509 *cert)
{
unsigned char digest[EVP_MAX_MD_SIZE];
unsigned int n_bytes;
struct ds fp;
char *subject;
ds_init(&fp);
if (!X509_digest(cert, EVP_sha1(), digest, &n_bytes)) {
ds_put_cstr(&fp, "<out of memory>");
} else {
unsigned int i;
for (i = 0; i < n_bytes; i++) {
if (i) {
ds_put_char(&fp, ':');
}
ds_put_format(&fp, "%02hhx", digest[i]);
}
}
subject = X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0);
VLOG_INFO("Trusting CA cert from %s (%s) (fingerprint %s)", file_name,
subject ? subject : "<out of memory>", ds_cstr(&fp));
free(subject);
ds_destroy(&fp);
}
/* Sets 'file_name' as the name of the file from which to read the CA
* certificate used to verify the peer within SSL connections. If 'bootstrap'
* is false, the file must exist. If 'bootstrap' is false, then the file is
* read if it is exists; if it does not, then it will be created from the CA
* certificate received from the peer on the first SSL connection. */
void
vconn_ssl_set_ca_cert_file(const char *file_name, bool bootstrap)
{
X509 **certs;
size_t n_certs;
struct stat s;
if (ssl_init()) {
return;
}
if (bootstrap && stat(file_name, &s) && errno == ENOENT) {
bootstrap_ca_cert = true;
ca_cert_file = xstrdup(file_name);
} else if (!read_cert_file(file_name, &certs, &n_certs)) {
size_t i;
/* Set up list of CAs that the server will accept from the client. */
for (i = 0; i < n_certs; i++) {
/* SSL_CTX_add_client_CA makes a copy of the relevant data. */
if (SSL_CTX_add_client_CA(ctx, certs[i]) != 1) {
VLOG_ERR("failed to add client certificate %d from %s: %s",
i, file_name,
ERR_error_string(ERR_get_error(), NULL));
} else {
log_ca_cert(file_name, certs[i]);
}
X509_free(certs[i]);
}
/* Set up CAs for OpenSSL to trust in verifying the peer's
* certificate. */
if (SSL_CTX_load_verify_locations(ctx, file_name, NULL) != 1) {
VLOG_ERR("SSL_CTX_load_verify_locations: %s",
ERR_error_string(ERR_get_error(), NULL));
return;
}
has_ca_cert = true;
}
}
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