diff --git a/modules/ssl/ssl_engine_init.c b/modules/ssl/ssl_engine_init.c
index b286053..8b6c34f 100644
--- a/modules/ssl/ssl_engine_init.c
+++ b/modules/ssl/ssl_engine_init.c
@@ -824,6 +824,13 @@ static apr_status_t ssl_init_ctx_protocol(server_rec *s,
SSL_CTX_set_keylog_callback(ctx, modssl_callback_keylog);
}
#endif
+
+#ifdef SSL_OP_NO_RENEGOTIATION
+ /* For server-side SSL_CTX, disable renegotiation by default.. */
+ if (!mctx->pkp) {
+ SSL_CTX_set_options(ctx, SSL_OP_NO_RENEGOTIATION);
+ }
+#endif
return APR_SUCCESS;
}
@@ -845,6 +852,14 @@ static void ssl_init_ctx_session_cache(server_rec *s,
}
}
+#ifdef SSL_OP_NO_RENEGOTIATION
+/* OpenSSL-level renegotiation protection. */
+#define MODSSL_BLOCKS_RENEG (0)
+#else
+/* mod_ssl-level renegotiation protection. */
+#define MODSSL_BLOCKS_RENEG (1)
+#endif
+
static void ssl_init_ctx_callbacks(server_rec *s,
apr_pool_t *p,
apr_pool_t *ptemp,
@@ -854,7 +869,13 @@ static void ssl_init_ctx_callbacks(server_rec *s,
SSL_CTX_set_tmp_dh_callback(ctx, ssl_callback_TmpDH);
- SSL_CTX_set_info_callback(ctx, ssl_callback_Info);
+ /* The info callback is used for debug-level tracing. For OpenSSL
+ * versions where SSL_OP_NO_RENEGOTIATION is not available, the
+ * callback is also used to prevent use of client-initiated
+ * renegotiation. Enable it in either case. */
+ if (APLOGdebug(s) || MODSSL_BLOCKS_RENEG) {
+ SSL_CTX_set_info_callback(ctx, ssl_callback_Info);
+ }
#ifdef HAVE_TLS_ALPN
SSL_CTX_set_alpn_select_cb(ctx, ssl_callback_alpn_select, NULL);
diff --git a/modules/ssl/ssl_engine_io.c b/modules/ssl/ssl_engine_io.c
index 836bfdb..0958135 100644
--- a/modules/ssl/ssl_engine_io.c
+++ b/modules/ssl/ssl_engine_io.c
@@ -200,11 +200,13 @@ static int bio_filter_out_write(BIO *bio, const char *in, int inl)
apr_bucket *e;
int need_flush;
+#ifndef SSL_OP_NO_RENEGOTIATION
/* Abort early if the client has initiated a renegotiation. */
if (outctx->filter_ctx->config->reneg_state == RENEG_ABORT) {
outctx->rc = APR_ECONNABORTED;
return -1;
}
+#endif
/* when handshaking we'll have a small number of bytes.
* max size SSL will pass us here is about 16k.
@@ -458,11 +460,13 @@ static int bio_filter_in_read(BIO *bio, char *in, int inlen)
if (!in)
return 0;
+#ifndef SSL_OP_NO_RENEGOTIATION
/* Abort early if the client has initiated a renegotiation. */
if (inctx->filter_ctx->config->reneg_state == RENEG_ABORT) {
inctx->rc = APR_ECONNABORTED;
return -1;
}
+#endif
BIO_clear_retry_flags(bio);
diff --git a/modules/ssl/ssl_engine_kernel.c b/modules/ssl/ssl_engine_kernel.c
index e217b9d..21f701f 100644
--- a/modules/ssl/ssl_engine_kernel.c
+++ b/modules/ssl/ssl_engine_kernel.c
@@ -992,7 +992,7 @@ static int ssl_hook_Access_classic(request_rec *r, SSLSrvConfigRec *sc, SSLDirCo
/* Toggle the renegotiation state to allow the new
* handshake to proceed. */
- sslconn->reneg_state = RENEG_ALLOW;
+ modssl_set_reneg_state(sslconn, RENEG_ALLOW);
SSL_renegotiate(ssl);
SSL_do_handshake(ssl);
@@ -1019,7 +1019,7 @@ static int ssl_hook_Access_classic(request_rec *r, SSLSrvConfigRec *sc, SSLDirCo
*/
SSL_peek(ssl, peekbuf, 0);
- sslconn->reneg_state = RENEG_REJECT;
+ modssl_set_reneg_state(sslconn, RENEG_REJECT);
if (!SSL_is_init_finished(ssl)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02261)
@@ -1078,7 +1078,7 @@ static int ssl_hook_Access_modern(request_rec *r, SSLSrvConfigRec *sc, SSLDirCon
(sc->server->auth.verify_mode != SSL_CVERIFY_UNSET)) {
int vmode_inplace, vmode_needed;
int change_vmode = FALSE;
- int old_state, n, rc;
+ int n, rc;
vmode_inplace = SSL_get_verify_mode(ssl);
vmode_needed = SSL_VERIFY_NONE;
@@ -1180,8 +1180,6 @@ static int ssl_hook_Access_modern(request_rec *r, SSLSrvConfigRec *sc, SSLDirCon
return HTTP_FORBIDDEN;
}
- old_state = sslconn->reneg_state;
- sslconn->reneg_state = RENEG_ALLOW;
modssl_set_app_data2(ssl, r);
SSL_do_handshake(ssl);
@@ -1191,7 +1189,6 @@ static int ssl_hook_Access_modern(request_rec *r, SSLSrvConfigRec *sc, SSLDirCon
*/
SSL_peek(ssl, peekbuf, 0);
- sslconn->reneg_state = old_state;
modssl_set_app_data2(ssl, NULL);
/*
@@ -2271,8 +2268,8 @@ static void log_tracing_state(const SSL *ssl, conn_rec *c,
/*
* This callback function is executed while OpenSSL processes the SSL
* handshake and does SSL record layer stuff. It's used to trap
- * client-initiated renegotiations, and for dumping everything to the
- * log.
+ * client-initiated renegotiations (where SSL_OP_NO_RENEGOTIATION is
+ * not available), and for dumping everything to the log.
*/
void ssl_callback_Info(const SSL *ssl, int where, int rc)
{
@@ -2284,14 +2281,12 @@ void ssl_callback_Info(const SSL *ssl, int where, int rc)
return;
}
- /* With TLS 1.3 this callback may be called multiple times on the first
- * negotiation, so the below logic to detect renegotiations can't work.
- * Fortunately renegotiations are forbidden starting with TLS 1.3, and
- * this is enforced by OpenSSL so there's nothing to be done here.
- */
-#if SSL_HAVE_PROTOCOL_TLSV1_3
- if (SSL_version(ssl) < TLS1_3_VERSION)
-#endif
+#ifndef SSL_OP_NO_RENEGOTIATION
+ /* With OpenSSL < 1.1.1 (implying TLS v1.2 or earlier), this
+ * callback is used to block client-initiated renegotiation. With
+ * TLSv1.3 it is unnecessary since renegotiation is forbidden at
+ * protocol level. Otherwise (TLSv1.2 with OpenSSL >=1.1.1),
+ * SSL_OP_NO_RENEGOTIATION is used to block renegotiation. */
{
SSLConnRec *sslconn;
@@ -2316,6 +2311,7 @@ void ssl_callback_Info(const SSL *ssl, int where, int rc)
sslconn->reneg_state = RENEG_REJECT;
}
}
+#endif
s = mySrvFromConn(c);
if (s && APLOGdebug(s)) {
diff --git a/modules/ssl/ssl_private.h b/modules/ssl/ssl_private.h
index 2514407..f4e5ac9 100644
--- a/modules/ssl/ssl_private.h
+++ b/modules/ssl/ssl_private.h
@@ -508,6 +508,16 @@ typedef struct {
apr_time_t source_mtime;
} ssl_asn1_t;
+typedef enum {
+ RENEG_INIT = 0, /* Before initial handshake */
+ RENEG_REJECT, /* After initial handshake; any client-initiated
+ * renegotiation should be rejected */
+ RENEG_ALLOW, /* A server-initiated renegotiation is taking
+ * place (as dictated by configuration) */
+ RENEG_ABORT /* Renegotiation initiated by client, abort the
+ * connection */
+} modssl_reneg_state;
+
/**
* Define the mod_ssl per-module configuration structure
* (i.e. the global configuration for each httpd process)
@@ -540,18 +550,13 @@ typedef struct {
NON_SSL_SET_ERROR_MSG /* Need to set the error message */
} non_ssl_request;
- /* Track the handshake/renegotiation state for the connection so
- * that all client-initiated renegotiations can be rejected, as a
- * partial fix for CVE-2009-3555. */
- enum {
- RENEG_INIT = 0, /* Before initial handshake */
- RENEG_REJECT, /* After initial handshake; any client-initiated
- * renegotiation should be rejected */
- RENEG_ALLOW, /* A server-initiated renegotiation is taking
- * place (as dictated by configuration) */
- RENEG_ABORT /* Renegotiation initiated by client, abort the
- * connection */
- } reneg_state;
+#ifndef SSL_OP_NO_RENEGOTIATION
+ /* For OpenSSL < 1.1.1, track the handshake/renegotiation state
+ * for the connection to block client-initiated renegotiations.
+ * For OpenSSL >=1.1.1, the SSL_OP_NO_RENEGOTIATION flag is used in
+ * the SSL * options state with equivalent effect. */
+ modssl_reneg_state reneg_state;
+#endif
server_rec *server;
SSLDirConfigRec *dc;
@@ -1130,6 +1135,9 @@ int ssl_is_challenge(conn_rec *c, const char *servername,
* the configured ENGINE. */
int modssl_is_engine_id(const char *name);
+/* Set the renegotation state for connection. */
+void modssl_set_reneg_state(SSLConnRec *sslconn, modssl_reneg_state state);
+
#endif /* SSL_PRIVATE_H */
/** @} */
diff --git a/modules/ssl/ssl_util_ssl.c b/modules/ssl/ssl_util_ssl.c
index 4fa089b..3413d83 100644
--- a/modules/ssl/ssl_util_ssl.c
+++ b/modules/ssl/ssl_util_ssl.c
@@ -504,3 +504,19 @@ char *modssl_SSL_SESSION_id2sz(IDCONST unsigned char *id, int idlen,
return str;
}
+
+void modssl_set_reneg_state(SSLConnRec *sslconn, modssl_reneg_state state)
+{
+#ifdef SSL_OP_NO_RENEGOTIATION
+ switch (state) {
+ case RENEG_ALLOW:
+ SSL_clear_options(sslconn->ssl, SSL_OP_NO_RENEGOTIATION);
+ break;
+ default:
+ SSL_set_options(sslconn->ssl, SSL_OP_NO_RENEGOTIATION);
+ break;
+ }
+#else
+ sslconn->reneg_state = state;
+#endif
+}