#include <sys/fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
+#include "coverage.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 "shash.h"
#include "socket-util.h"
#include "util.h"
#include "stream-provider.h"
#include "stream.h"
-
+#include "timeval.h"
#include "vlog.h"
-#define THIS_MODULE VLM_stream_ssl
+
+VLOG_DEFINE_THIS_MODULE(stream_ssl)
/* Active SSL. */
{
struct stream stream;
enum ssl_state state;
- int connect_error;
enum session_type type;
int fd;
SSL *ssl;
struct ofpbuf *txbuf;
+ unsigned int session_nr;
/* rx_want and tx_want record the result of the last call to SSL_read()
* and SSL_write(), respectively:
* deadlock and livelock situations above.
*/
int rx_want, tx_want;
+
+ /* A few bytes of header data in case SSL negotiation fails. */
+ uint8_t head[2];
+ short int n_head;
};
/* SSL context created by ssl_init(). */
static SSL_CTX *ctx;
-/* Required configuration. */
-static bool has_private_key, has_certificate, has_ca_cert;
+/* Maps from stream target (e.g. "127.0.0.1:1234") to SSL_SESSION *. The
+ * sessions are those from the last SSL connection to the given target.
+ * OpenSSL caches server-side sessions internally, so this cache is only used
+ * for client connections.
+ *
+ * The stream_ssl module owns a reference to each of the sessions in this
+ * table, so they must be freed with SSL_SESSION_free() when they are no
+ * longer needed. */
+static struct shash client_sessions = SHASH_INITIALIZER(&client_sessions);
+
+/* Maximum number of client sessions to cache. Ordinarily I'd expect that one
+ * session would be sufficient but this should cover it. */
+#define MAX_CLIENT_SESSION_CACHE 16
+
+struct ssl_config_file {
+ bool read; /* Whether the file was successfully read. */
+ char *file_name; /* Configured file name, if any. */
+ struct timespec mtime; /* File mtime as of last time we read it. */
+};
+
+/* SSL configuration files. */
+static struct ssl_config_file private_key;
+static struct ssl_config_file certificate;
+static struct ssl_config_file ca_cert;
+
+/* Ordinarily, the SSL client and server verify each other's certificates using
+ * a CA certificate. Setting this to false disables this behavior. (This is a
+ * security risk.) */
+static bool verify_peer_cert = true;
/* 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. */
+ * available. 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, 'bootstrap_ca_cert' is true. */
static bool bootstrap_ca_cert;
-static char *ca_cert_file;
+
+/* Session number. Used in debug logging messages to uniquely identify a
+ * session. */
+static unsigned int next_session_nr;
/* Who knows what can trigger various SSL errors, so let's throttle them down
* quite a bit. */
int *want);
static DH *tmp_dh_callback(SSL *ssl, int is_export OVS_UNUSED, int keylength);
static void log_ca_cert(const char *file_name, X509 *cert);
+static void stream_ssl_set_ca_cert_file__(const char *file_name,
+ bool bootstrap);
+static void ssl_protocol_cb(int write_p, int version, int content_type,
+ const void *, size_t, SSL *, void *sslv_);
static short int
want_to_poll_events(int want)
/* Check for all the needful configuration. */
retval = 0;
- if (!has_private_key) {
+ if (!private_key.read) {
VLOG_ERR("Private key must be configured to use SSL");
retval = ENOPROTOOPT;
}
- if (!has_certificate) {
+ if (!certificate.read) {
VLOG_ERR("Certificate must be configured to use SSL");
retval = ENOPROTOOPT;
}
- if (!has_ca_cert && !bootstrap_ca_cert) {
+ if (!ca_cert.read && verify_peer_cert && !bootstrap_ca_cert) {
VLOG_ERR("CA certificate must be configured to use SSL");
retval = ENOPROTOOPT;
}
retval = ENOPROTOOPT;
goto error;
}
- if (bootstrap_ca_cert && type == CLIENT) {
+ if (!verify_peer_cert || (bootstrap_ca_cert && type == CLIENT)) {
SSL_set_verify(ssl, SSL_VERIFY_NONE, NULL);
}
sslv->ssl = ssl;
sslv->txbuf = NULL;
sslv->rx_want = sslv->tx_want = SSL_NOTHING;
+ sslv->session_nr = next_session_nr++;
+ sslv->n_head = 0;
+
+ if (VLOG_IS_DBG_ENABLED()) {
+ SSL_set_msg_callback(ssl, ssl_protocol_cb);
+ SSL_set_msg_callback_arg(ssl, sslv);
+ }
+
*streamp = &sslv->stream;
return 0;
{
struct ssl_stream *sslv = ssl_stream_cast(stream);
STACK_OF(X509) *chain;
- X509 *ca_cert;
+ X509 *cert;
FILE *file;
int error;
int fd;
"peer");
return EPROTO;
}
- ca_cert = sk_X509_value(chain, sk_X509_num(chain) - 1);
+ cert = sk_X509_value(chain, sk_X509_num(chain) - 1);
- /* Check that 'ca_cert' is self-signed. Otherwise it is not a CA
+ /* Check that '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);
+ error = X509_check_issued(cert, cert);
if (error) {
VLOG_ERR("could not bootstrap CA cert: obtained certificate is "
"not self-signed (%s)",
return EPROTO;
}
- fd = open(ca_cert_file, O_CREAT | O_EXCL | O_WRONLY, 0444);
+ fd = open(ca_cert.file_name, 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;
+ if (errno == EEXIST) {
+ VLOG_INFO("reading CA cert %s created by another process",
+ ca_cert.file_name);
+ stream_ssl_set_ca_cert_file(ca_cert.file_name, true);
+ return EPROTO;
+ } else {
+ VLOG_ERR("could not bootstrap CA cert: creating %s failed: %s",
+ ca_cert.file_name, strerror(errno));
+ return errno;
+ }
}
file = fdopen(fd, "w");
int error = errno;
VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s",
strerror(error));
- unlink(ca_cert_file);
+ unlink(ca_cert.file_name);
return error;
}
- if (!PEM_write_X509(file, ca_cert)) {
+ if (!PEM_write_X509(file, 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));
+ "%s", ca_cert.file_name,
+ ERR_error_string(ERR_get_error(), NULL));
fclose(file);
- unlink(ca_cert_file);
+ unlink(ca_cert.file_name);
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);
+ ca_cert.file_name, strerror(error));
+ unlink(ca_cert.file_name);
return error;
}
- VLOG_INFO("successfully bootstrapped CA cert to %s", ca_cert_file);
- log_ca_cert(ca_cert_file, ca_cert);
+ VLOG_INFO("successfully bootstrapped CA cert to %s", ca_cert.file_name);
+ log_ca_cert(ca_cert.file_name, cert);
bootstrap_ca_cert = false;
- has_ca_cert = true;
+ ca_cert.read = 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_add_client_CA makes a copy of cert's relevant data. */
+ SSL_CTX_add_client_CA(ctx, 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) {
+ * 'cert' is owned by sslv->ssl, so we need to duplicate it. */
+ cert = X509_dup(cert);
+ if (!cert) {
out_of_memory();
}
- if (SSL_CTX_load_verify_locations(ctx, ca_cert_file, NULL) != 1) {
+ if (SSL_CTX_load_verify_locations(ctx, ca_cert.file_name, NULL) != 1) {
VLOG_ERR("SSL_CTX_load_verify_locations: %s",
ERR_error_string(ERR_get_error(), NULL));
return EPROTO;
return EPROTO;
}
+static void
+ssl_delete_session(struct shash_node *node)
+{
+ SSL_SESSION *session = node->data;
+ SSL_SESSION_free(session);
+ shash_delete(&client_sessions, node);
+}
+
+/* Find and free any previously cached session for 'stream''s target. */
+static void
+ssl_flush_session(struct stream *stream)
+{
+ struct shash_node *node;
+
+ node = shash_find(&client_sessions, stream_get_name(stream));
+ if (node) {
+ ssl_delete_session(node);
+ }
+}
+
+/* Add 'stream''s session to the cache for its target, so that it will be
+ * reused for future SSL connections to the same target. */
+static void
+ssl_cache_session(struct stream *stream)
+{
+ struct ssl_stream *sslv = ssl_stream_cast(stream);
+ SSL_SESSION *session;
+
+ /* Statistics. */
+ COVERAGE_INC(ssl_session);
+ if (SSL_session_reused(sslv->ssl)) {
+ COVERAGE_INC(ssl_session_reused);
+ }
+
+ /* Get session from stream. */
+ session = SSL_get1_session(sslv->ssl);
+ if (session) {
+ SSL_SESSION *old_session;
+
+ old_session = shash_replace(&client_sessions, stream_get_name(stream),
+ session);
+ if (old_session) {
+ /* Free the session that we replaced. (We might actually have
+ * session == old_session, but either way we have to free it to
+ * avoid leaking a reference.) */
+ SSL_SESSION_free(old_session);
+ } else if (shash_count(&client_sessions) > MAX_CLIENT_SESSION_CACHE) {
+ for (;;) {
+ struct shash_node *node = shash_random_node(&client_sessions);
+ if (node->data != session) {
+ ssl_delete_session(node);
+ break;
+ }
+ }
+ }
+ } else {
+ /* There is no new session. This doesn't really make sense because
+ * this function is only called upon successful connection and there
+ * should always be a new session in that case. But I don't trust
+ * OpenSSL so I'd rather handle this case anyway. */
+ ssl_flush_session(stream);
+ }
+}
+
static int
ssl_connect(struct stream *stream)
{
/* Fall through. */
case STATE_SSL_CONNECTING:
+ /* Capture the first few bytes of received data so that we can guess
+ * what kind of funny data we've been sent if SSL negotation fails. */
+ if (sslv->n_head <= 0) {
+ sslv->n_head = recv(sslv->fd, sslv->head, sizeof sslv->head,
+ MSG_PEEK);
+ }
+
+ /* Grab SSL session information from the cache. */
+ if (sslv->type == CLIENT) {
+ SSL_SESSION *session = shash_find_data(&client_sessions,
+ stream_get_name(stream));
+ if (session) {
+ SSL_set_session(sslv->ssl, session);
+ }
+ }
+
retval = (sslv->type == CLIENT
? SSL_connect(sslv->ssl) : SSL_accept(sslv->ssl));
if (retval != 1) {
return EAGAIN;
} else {
int unused;
+
+ if (sslv->type == CLIENT) {
+ /* Delete any cached session for this stream's target.
+ * Otherwise a single error causes recurring errors that
+ * don't resolve until the SSL client or server is
+ * restarted. (It can take dozens of reused connections to
+ * see this behavior, so this is difficult to test.) If we
+ * delete the session on the first error, though, the error
+ * only occurs once and then resolves itself. */
+ ssl_flush_session(stream);
+ }
+
interpret_ssl_error((sslv->type == CLIENT ? "SSL_connect"
: "SSL_accept"), retval, error, &unused);
shutdown(sslv->fd, SHUT_RDWR);
+ stream_report_content(sslv->head, sslv->n_head, STREAM_SSL,
+ THIS_MODULE, stream_get_name(stream));
return EPROTO;
}
} else if (bootstrap_ca_cert) {
return do_ca_cert_bootstrap(stream);
- } else if ((SSL_get_verify_mode(sslv->ssl)
- & (SSL_VERIFY_NONE | SSL_VERIFY_PEER))
- != SSL_VERIFY_PEER) {
+ } else if (verify_peer_cert
+ && ((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
VLOG_ERR("rejecting SSL connection during bootstrap race window");
return EPROTO;
} else {
+ if (sslv->type == CLIENT) {
+ ssl_cache_session(stream);
+ }
return 0;
}
}
* background. */
SSL_shutdown(sslv->ssl);
+ /* SSL_shutdown() might have signaled an error, in which case we need to
+ * flush it out of the OpenSSL error queue or the next OpenSSL operation
+ * will falsely signal an error. */
+ ERR_clear_error();
+
SSL_free(sslv->ssl);
close(sslv->fd);
free(sslv);
/* Returns true if SSL is at least partially configured. */
bool
-stream_ssl_is_configured(void)
+stream_ssl_is_configured(void)
{
- return has_private_key || has_certificate || has_ca_cert;
+ return private_key.file_name || certificate.file_name || ca_cert.file_name;
}
-void
-stream_ssl_set_private_key_file(const char *file_name)
+static bool
+update_ssl_config(struct ssl_config_file *config, const char *file_name)
{
- if (ssl_init()) {
- return;
+ struct timespec mtime;
+
+ if (ssl_init() || !file_name) {
+ return false;
+ }
+
+ /* If the file name hasn't changed and neither has the file contents, stop
+ * here. */
+ get_mtime(file_name, &mtime);
+ if (config->file_name
+ && !strcmp(config->file_name, file_name)
+ && mtime.tv_sec == config->mtime.tv_sec
+ && mtime.tv_nsec == config->mtime.tv_nsec) {
+ return false;
}
- if (SSL_CTX_use_PrivateKey_file(ctx, file_name, SSL_FILETYPE_PEM) != 1) {
+
+ /* Update 'config'. */
+ config->mtime = mtime;
+ if (file_name != config->file_name) {
+ free(config->file_name);
+ config->file_name = xstrdup(file_name);
+ }
+ return true;
+}
+
+static void
+stream_ssl_set_private_key_file__(const char *file_name)
+{
+ if (SSL_CTX_use_PrivateKey_file(ctx, file_name, SSL_FILETYPE_PEM) == 1) {
+ private_key.read = true;
+ } else {
VLOG_ERR("SSL_use_PrivateKey_file: %s",
ERR_error_string(ERR_get_error(), NULL));
- return;
}
- has_private_key = true;
}
void
-stream_ssl_set_certificate_file(const char *file_name)
+stream_ssl_set_private_key_file(const char *file_name)
{
- if (ssl_init()) {
- return;
+ if (update_ssl_config(&private_key, file_name)) {
+ stream_ssl_set_private_key_file__(file_name);
}
- if (SSL_CTX_use_certificate_chain_file(ctx, file_name) != 1) {
+}
+
+static void
+stream_ssl_set_certificate_file__(const char *file_name)
+{
+ if (SSL_CTX_use_certificate_chain_file(ctx, file_name) == 1) {
+ certificate.read = true;
+ } else {
VLOG_ERR("SSL_use_certificate_file: %s",
ERR_error_string(ERR_get_error(), NULL));
- return;
}
- has_certificate = true;
+}
+
+void
+stream_ssl_set_certificate_file(const char *file_name)
+{
+ if (update_ssl_config(&certificate, file_name)) {
+ stream_ssl_set_certificate_file__(file_name);
+ }
+}
+
+/* Sets the private key and certificate files in one operation. Use this
+ * interface, instead of calling stream_ssl_set_private_key_file() and
+ * stream_ssl_set_certificate_file() individually, in the main loop of a
+ * long-running program whose key and certificate might change at runtime.
+ *
+ * This is important because of OpenSSL's behavior. If an OpenSSL context
+ * already has a certificate, and stream_ssl_set_private_key_file() is called
+ * to install a new private key, OpenSSL will report an error because the new
+ * private key does not match the old certificate. The other order, of setting
+ * a new certificate, then setting a new private key, does work.
+ *
+ * If this were the only problem, calling stream_ssl_set_certificate_file()
+ * before stream_ssl_set_private_key_file() would fix it. But, if the private
+ * key is changed before the certificate (e.g. someone "scp"s or "mv"s the new
+ * private key in place before the certificate), then OpenSSL would reject that
+ * change, and then the change of certificate would succeed, but there would be
+ * no associated private key (because it had only changed once and therefore
+ * there was no point in re-reading it).
+ *
+ * This function avoids both problems by, whenever either the certificate or
+ * the private key file changes, re-reading both of them, in the correct order.
+ */
+void
+stream_ssl_set_key_and_cert(const char *private_key_file,
+ const char *certificate_file)
+{
+ if (update_ssl_config(&private_key, private_key_file)
+ || update_ssl_config(&certificate, certificate_file)) {
+ stream_ssl_set_certificate_file__(certificate_file);
+ stream_ssl_set_private_key_file__(private_key_file);
+ }
}
/* Reads the X509 certificate or certificates in file 'file_name'. On success,
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);
+ OPENSSL_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
-stream_ssl_set_ca_cert_file(const char *file_name, bool bootstrap)
+static void
+stream_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) {
+ if (!strcmp(file_name, "none")) {
+ verify_peer_cert = false;
+ VLOG_WARN("Peer certificate validation disabled "
+ "(this is a security risk)");
+ } else 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;
return;
}
- has_ca_cert = true;
+ bootstrap_ca_cert = false;
}
+ ca_cert.read = true;
+}
+
+/* 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
+stream_ssl_set_ca_cert_file(const char *file_name, bool bootstrap)
+{
+ if (!update_ssl_config(&ca_cert, file_name)) {
+ return;
+ }
+
+ stream_ssl_set_ca_cert_file__(file_name, bootstrap);
+}
+\f
+/* SSL protocol logging. */
+
+static const char *
+ssl_alert_level_to_string(uint8_t type)
+{
+ switch (type) {
+ case 1: return "warning";
+ case 2: return "fatal";
+ default: return "<unknown>";
+ }
+}
+
+static const char *
+ssl_alert_description_to_string(uint8_t type)
+{
+ switch (type) {
+ case 0: return "close_notify";
+ case 10: return "unexpected_message";
+ case 20: return "bad_record_mac";
+ case 21: return "decryption_failed";
+ case 22: return "record_overflow";
+ case 30: return "decompression_failure";
+ case 40: return "handshake_failure";
+ case 42: return "bad_certificate";
+ case 43: return "unsupported_certificate";
+ case 44: return "certificate_revoked";
+ case 45: return "certificate_expired";
+ case 46: return "certificate_unknown";
+ case 47: return "illegal_parameter";
+ case 48: return "unknown_ca";
+ case 49: return "access_denied";
+ case 50: return "decode_error";
+ case 51: return "decrypt_error";
+ case 60: return "export_restriction";
+ case 70: return "protocol_version";
+ case 71: return "insufficient_security";
+ case 80: return "internal_error";
+ case 90: return "user_canceled";
+ case 100: return "no_renegotiation";
+ default: return "<unknown>";
+ }
+}
+
+static const char *
+ssl_handshake_type_to_string(uint8_t type)
+{
+ switch (type) {
+ case 0: return "hello_request";
+ case 1: return "client_hello";
+ case 2: return "server_hello";
+ case 11: return "certificate";
+ case 12: return "server_key_exchange";
+ case 13: return "certificate_request";
+ case 14: return "server_hello_done";
+ case 15: return "certificate_verify";
+ case 16: return "client_key_exchange";
+ case 20: return "finished";
+ default: return "<unknown>";
+ }
+}
+
+static void
+ssl_protocol_cb(int write_p, int version OVS_UNUSED, int content_type,
+ const void *buf_, size_t len, SSL *ssl OVS_UNUSED, void *sslv_)
+{
+ const struct ssl_stream *sslv = sslv_;
+ const uint8_t *buf = buf_;
+ struct ds details;
+
+ if (!VLOG_IS_DBG_ENABLED()) {
+ return;
+ }
+
+ ds_init(&details);
+ if (content_type == 20) {
+ ds_put_cstr(&details, "change_cipher_spec");
+ } else if (content_type == 21) {
+ ds_put_format(&details, "alert: %s, %s",
+ ssl_alert_level_to_string(buf[0]),
+ ssl_alert_description_to_string(buf[1]));
+ } else if (content_type == 22) {
+ ds_put_format(&details, "handshake: %s",
+ ssl_handshake_type_to_string(buf[0]));
+ } else {
+ ds_put_format(&details, "type %d", content_type);
+ }
+
+ VLOG_DBG("%s%u%s%s %s (%zu bytes)",
+ sslv->type == CLIENT ? "client" : "server",
+ sslv->session_nr, write_p ? "-->" : "<--",
+ stream_get_name(&sslv->stream), ds_cstr(&details), len);
+
+ ds_destroy(&details);
}
git://git.onelab.eu / sliver-openvswitch.git / blobdiff