X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fstream-ssl.c;h=9c7533d1e6346b8e4634f0220262d852dd43c773;hb=1ac788f67ff614662ce7d9af36d5eb7597f53a3f;hp=1944cb9ed302dae7460764ddbd8cbb9c21ed8182;hpb=ff1760f1c7b9664ddd5a1d525b343252b3fc947a;p=sliver-openvswitch.git diff --git a/lib/stream-ssl.c b/lib/stream-ssl.c index 1944cb9ed..9c7533d1e 100644 --- a/lib/stream-ssl.c +++ b/lib/stream-ssl.c @@ -30,20 +30,22 @@ #include #include #include +#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 "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. */ @@ -61,7 +63,6 @@ struct ssl_stream { struct stream stream; enum ssl_state state; - int connect_error; enum session_type type; int fd; SSL *ssl; @@ -134,6 +135,20 @@ struct ssl_stream /* SSL context created by ssl_init(). */ static SSL_CTX *ctx; +/* 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. */ @@ -370,7 +385,7 @@ do_ca_cert_bootstrap(struct stream *stream) file = fdopen(fd, "w"); if (!file) { - int error = errno; + error = errno; VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s", strerror(error)); unlink(ca_cert.file_name); @@ -387,7 +402,7 @@ do_ca_cert_bootstrap(struct stream *stream) } if (fclose(file)) { - int error = errno; + error = errno; VLOG_ERR("could not bootstrap CA cert: writing %s failed: %s", ca_cert.file_name, strerror(error)); unlink(ca_cert.file_name); @@ -417,6 +432,70 @@ do_ca_cert_bootstrap(struct stream *stream) 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) { @@ -440,6 +519,15 @@ ssl_connect(struct stream *stream) 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) { @@ -448,6 +536,18 @@ ssl_connect(struct stream *stream) 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); @@ -472,6 +572,9 @@ ssl_connect(struct stream *stream) VLOG_ERR("rejecting SSL connection during bootstrap race window"); return EPROTO; } else { + if (sslv->type == CLIENT) { + ssl_cache_session(stream); + } return 0; } } @@ -818,7 +921,7 @@ pssl_accept(struct pstream *pstream, struct stream **new_streamp) new_fd = accept(pssl->fd, &sin, &sin_len); if (new_fd < 0) { - int error = errno; + error = errno; if (error != EAGAIN) { VLOG_DBG_RL(&rl, "accept: %s", strerror(error)); } @@ -942,7 +1045,7 @@ tmp_dh_callback(SSL *ssl OVS_UNUSED, int is_export OVS_UNUSED, int keylength) /* Returns true if SSL is at least partially configured. */ bool -stream_ssl_is_configured(void) +stream_ssl_is_configured(void) { return private_key.file_name || certificate.file_name || ca_cert.file_name; } @@ -975,32 +1078,75 @@ update_ssl_config(struct ssl_config_file *config, const char *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)); + } +} + void stream_ssl_set_private_key_file(const char *file_name) { - if (!update_ssl_config(&private_key, file_name)) { - return; + if (update_ssl_config(&private_key, file_name)) { + stream_ssl_set_private_key_file__(file_name); } - if (SSL_CTX_use_PrivateKey_file(ctx, file_name, SSL_FILETYPE_PEM) != 1) { - VLOG_ERR("SSL_use_PrivateKey_file: %s", +} + +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; } - private_key.read = true; } void stream_ssl_set_certificate_file(const char *file_name) { - if (!update_ssl_config(&certificate, file_name)) { - return; + if (update_ssl_config(&certificate, file_name)) { + stream_ssl_set_certificate_file__(file_name); } - 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; +} + +/* 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); } - certificate.read = true; } /* Reads the X509 certificate or certificates in file 'file_name'. On success, @@ -1116,7 +1262,7 @@ log_ca_cert(const char *file_name, X509 *cert) 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 : "", ds_cstr(&fp)); - free(subject); + OPENSSL_free(subject); ds_destroy(&fp); }