/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* _ _ * _ __ ___ ___ __| | ___ ___| | mod_ssl * | '_ ` _ \ / _ \ / _` | / __/ __| | Apache Interface to OpenSSL * | | | | | | (_) | (_| | \__ \__ \ | * |_| |_| |_|\___/ \__,_|___|___/___/_| * |_____| * ssl_engine_kernel.c * The SSL engine kernel */ /* ``It took me fifteen years to discover I had no talent for programming, but I couldn't give it up because by that time I was too famous.'' -- Unknown */ #include "ssl_private.h" #include "util_md5.h" static void ssl_configure_env(request_rec *r, SSLConnRec *sslconn); #ifdef HAVE_TLSEXT static int ssl_find_vhost(void *servername, conn_rec *c, server_rec *s); #endif #define SWITCH_STATUS_LINE "HTTP/1.1 101 Switching Protocols" #define UPGRADE_HEADER "Upgrade: TLS/1.0, HTTP/1.1" #define CONNECTION_HEADER "Connection: Upgrade" /* Perform an upgrade-to-TLS for the given request, per RFC 2817. */ static apr_status_t upgrade_connection(request_rec *r) { struct conn_rec *conn = r->connection; apr_bucket_brigade *bb; SSLConnRec *sslconn; apr_status_t rv; SSL *ssl; ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02028) "upgrading connection to TLS"); bb = apr_brigade_create(r->pool, conn->bucket_alloc); rv = ap_fputstrs(conn->output_filters, bb, SWITCH_STATUS_LINE, CRLF, UPGRADE_HEADER, CRLF, CONNECTION_HEADER, CRLF, CRLF, NULL); if (rv == APR_SUCCESS) { APR_BRIGADE_INSERT_TAIL(bb, apr_bucket_flush_create(conn->bucket_alloc)); rv = ap_pass_brigade(conn->output_filters, bb); } if (rv) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02029) "failed to send 101 interim response for connection " "upgrade"); return rv; } ssl_init_ssl_connection(conn, r); sslconn = myConnConfig(conn); ssl = sslconn->ssl; /* Perform initial SSL handshake. */ SSL_set_accept_state(ssl); SSL_do_handshake(ssl); if (SSL_get_state(ssl) != SSL_ST_OK) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02030) "TLS upgrade handshake failed: not accepted by client!?"); return APR_ECONNABORTED; } return APR_SUCCESS; } /* Perform a speculative (and non-blocking) read from the connection * filters for the given request, to determine whether there is any * pending data to read. Return non-zero if there is, else zero. */ static int has_buffered_data(request_rec *r) { apr_bucket_brigade *bb; apr_off_t len; apr_status_t rv; int result; bb = apr_brigade_create(r->pool, r->connection->bucket_alloc); rv = ap_get_brigade(r->connection->input_filters, bb, AP_MODE_SPECULATIVE, APR_NONBLOCK_READ, 1); result = rv == APR_SUCCESS && apr_brigade_length(bb, 1, &len) == APR_SUCCESS && len > 0; apr_brigade_destroy(bb); return result; } /* * Post Read Request Handler */ int ssl_hook_ReadReq(request_rec *r) { SSLSrvConfigRec *sc = mySrvConfig(r->server); SSLConnRec *sslconn; const char *upgrade; #ifdef HAVE_TLSEXT const char *servername; #endif SSL *ssl; /* Perform TLS upgrade here if "SSLEngine optional" is configured, * SSL is not already set up for this connection, and the client * has sent a suitable Upgrade header. */ if (sc->enabled == SSL_ENABLED_OPTIONAL && !myConnConfig(r->connection) && (upgrade = apr_table_get(r->headers_in, "Upgrade")) != NULL && ap_find_token(r->pool, upgrade, "TLS/1.0")) { if (upgrade_connection(r)) { return HTTP_INTERNAL_SERVER_ERROR; } } sslconn = myConnConfig(r->connection); if (!sslconn) { return DECLINED; } if (sslconn->non_ssl_request == NON_SSL_SET_ERROR_MSG) { apr_table_setn(r->notes, "error-notes", "Reason: You're speaking plain HTTP to an SSL-enabled " "server port.
\n Instead use the HTTPS scheme to " "access this URL, please.
\n"); /* Now that we have caught this error, forget it. we are done * with using SSL on this request. */ sslconn->non_ssl_request = NON_SSL_OK; return HTTP_BAD_REQUEST; } /* * Get the SSL connection structure and perform the * delayed interlinking from SSL back to request_rec */ ssl = sslconn->ssl; if (!ssl) { return DECLINED; } #ifdef HAVE_TLSEXT /* * Perform SNI checks only on the initial request. In particular, * if these checks detect a problem, the checks shouldn't return an * error again when processing an ErrorDocument redirect for the * original problem. */ if (r->proxyreq != PROXYREQ_PROXY && ap_is_initial_req(r)) { if ((servername = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name))) { char *host, *scope_id; apr_port_t port; apr_status_t rv; /* * The SNI extension supplied a hostname. So don't accept requests * with either no hostname or a different hostname as this could * cause us to end up in a different virtual host as the one that * was used for the handshake causing different SSL parameters to * be applied as SSLProtocol, SSLCACertificateFile/Path and * SSLCADNRequestFile/Path cannot be renegotiated (SSLCA* due * to current limitations in OpenSSL, see * http://mail-archives.apache.org/mod_mbox/httpd-dev/200806.mbox/%3C48592955.2090303@velox.ch%3E * and * http://mail-archives.apache.org/mod_mbox/httpd-dev/201312.mbox/%3CCAKQ1sVNpOrdiBm-UPw1hEdSN7YQXRRjeaT-MCWbW_7mN%3DuFiOw%40mail.gmail.com%3E * ) */ if (!r->hostname) { ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, APLOGNO(02031) "Hostname %s provided via SNI, but no hostname" " provided in HTTP request", servername); return HTTP_BAD_REQUEST; } rv = apr_parse_addr_port(&host, &scope_id, &port, r->hostname, r->pool); if (rv != APR_SUCCESS || scope_id) { return HTTP_BAD_REQUEST; } if (strcasecmp(host, servername)) { ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, APLOGNO(02032) "Hostname %s provided via SNI and hostname %s provided" " via HTTP are different", servername, host); return HTTP_BAD_REQUEST; } } else if (((sc->strict_sni_vhost_check == SSL_ENABLED_TRUE) || (mySrvConfig(sslconn->server))->strict_sni_vhost_check == SSL_ENABLED_TRUE) && r->connection->vhost_lookup_data) { /* * We are using a name based configuration here, but no hostname was * provided via SNI. Don't allow that if are requested to do strict * checking. Check whether this strict checking was set up either in the * server config we used for handshaking or in our current server. * This should avoid insecure configuration by accident. */ ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, APLOGNO(02033) "No hostname was provided via SNI for a name based" " virtual host"); apr_table_setn(r->notes, "error-notes", "Reason: The client software did not provide a " "hostname using Server Name Indication (SNI), " "which is required to access this server.
\n"); return HTTP_FORBIDDEN; } } #endif SSL_set_app_data2(ssl, r); /* * Log information about incoming HTTPS requests */ if (APLOGrinfo(r) && ap_is_initial_req(r)) { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02034) "%s HTTPS request received for child %ld (server %s)", (r->connection->keepalives <= 0 ? "Initial (No.1)" : apr_psprintf(r->pool, "Subsequent (No.%d)", r->connection->keepalives+1)), r->connection->id, ssl_util_vhostid(r->pool, r->server)); } /* SetEnvIf ssl-*-shutdown flags can only be per-server, * so they won't change across keepalive requests */ if (sslconn->shutdown_type == SSL_SHUTDOWN_TYPE_UNSET) { ssl_configure_env(r, sslconn); } return DECLINED; } /* * Move SetEnvIf information from request_rec to conn_rec/BUFF * to allow the close connection handler to use them. */ static void ssl_configure_env(request_rec *r, SSLConnRec *sslconn) { int i; const apr_array_header_t *arr = apr_table_elts(r->subprocess_env); const apr_table_entry_t *elts = (const apr_table_entry_t *)arr->elts; sslconn->shutdown_type = SSL_SHUTDOWN_TYPE_STANDARD; for (i = 0; i < arr->nelts; i++) { const char *key = elts[i].key; switch (*key) { case 's': /* being case-sensitive here. * and not checking for the -shutdown since these are the only * SetEnvIf "flags" we support */ if (!strncmp(key+1, "sl-", 3)) { key += 4; if (!strncmp(key, "unclean", 7)) { sslconn->shutdown_type = SSL_SHUTDOWN_TYPE_UNCLEAN; } else if (!strncmp(key, "accurate", 8)) { sslconn->shutdown_type = SSL_SHUTDOWN_TYPE_ACCURATE; } return; /* should only ever be one ssl-*-shutdown */ } break; } } } /* * Access Handler */ int ssl_hook_Access(request_rec *r) { SSLDirConfigRec *dc = myDirConfig(r); SSLSrvConfigRec *sc = mySrvConfig(r->server); SSLConnRec *sslconn = myConnConfig(r->connection); SSL *ssl = sslconn ? sslconn->ssl : NULL; server_rec *handshakeserver = sslconn ? sslconn->server : NULL; SSL_CTX *ctx = NULL; apr_array_header_t *requires; ssl_require_t *ssl_requires; int ok, i; BOOL renegotiate = FALSE, renegotiate_quick = FALSE; X509 *cert; X509 *peercert; X509_STORE *cert_store = NULL; X509_STORE_CTX cert_store_ctx; STACK_OF(SSL_CIPHER) *cipher_list_old = NULL, *cipher_list = NULL; const SSL_CIPHER *cipher = NULL; int depth, verify_old, verify, n; if (ssl) { ctx = SSL_get_SSL_CTX(ssl); } /* * Support for SSLRequireSSL directive */ if (dc->bSSLRequired && !ssl) { if (sc->enabled == SSL_ENABLED_OPTIONAL) { /* This vhost was configured for optional SSL, just tell the * client that we need to upgrade. */ apr_table_setn(r->err_headers_out, "Upgrade", "TLS/1.0, HTTP/1.1"); apr_table_setn(r->err_headers_out, "Connection", "Upgrade"); return HTTP_UPGRADE_REQUIRED; } ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02219) "access to %s failed, reason: %s", r->filename, "SSL connection required"); /* remember forbidden access for strict require option */ apr_table_setn(r->notes, "ssl-access-forbidden", "1"); return HTTP_FORBIDDEN; } /* * Check to see whether SSL is in use; if it's not, then no * further access control checks are relevant. (the test for * sc->enabled is probably strictly unnecessary) */ if (sc->enabled == SSL_ENABLED_FALSE || !ssl) { return DECLINED; } #ifdef HAVE_SRP /* * Support for per-directory reconfigured SSL connection parameters * * We do not force any renegotiation if the user is already authenticated * via SRP. * */ if (SSL_get_srp_username(ssl)) { return DECLINED; } #endif /* * Support for per-directory reconfigured SSL connection parameters. * * This is implemented by forcing an SSL renegotiation with the * reconfigured parameter suite. But Apache's internal API processing * makes our life very hard here, because when internal sub-requests occur * we nevertheless should avoid multiple unnecessary SSL handshakes (they * require extra network I/O and especially time to perform). * * But the optimization for filtering out the unnecessary handshakes isn't * obvious and trivial. Especially because while Apache is in its * sub-request processing the client could force additional handshakes, * too. And these take place perhaps without our notice. So the only * possibility is to explicitly _ask_ OpenSSL whether the renegotiation * has to be performed or not. It has to performed when some parameters * which were previously known (by us) are not those we've now * reconfigured (as known by OpenSSL) or (in optimized way) at least when * the reconfigured parameter suite is stronger (more restrictions) than * the currently active one. */ /* * Override of SSLCipherSuite * * We provide two options here: * * o The paranoid and default approach where we force a renegotiation when * the cipher suite changed in _any_ way (which is straight-forward but * often forces renegotiations too often and is perhaps not what the * user actually wanted). * * o The optimized and still secure way where we force a renegotiation * only if the currently active cipher is no longer contained in the * reconfigured/new cipher suite. Any other changes are not important * because it's the servers choice to select a cipher from the ones the * client supports. So as long as the current cipher is still in the new * cipher suite we're happy. Because we can assume we would have * selected it again even when other (better) ciphers exists now in the * new cipher suite. This approach is fine because the user explicitly * has to enable this via ``SSLOptions +OptRenegotiate''. So we do no * implicit optimizations. */ if (dc->szCipherSuite || (r->server != handshakeserver)) { /* remember old state */ if (dc->nOptions & SSL_OPT_OPTRENEGOTIATE) { cipher = SSL_get_current_cipher(ssl); } else { cipher_list_old = (STACK_OF(SSL_CIPHER) *)SSL_get_ciphers(ssl); if (cipher_list_old) { cipher_list_old = sk_SSL_CIPHER_dup(cipher_list_old); } } /* configure new state */ if ((dc->szCipherSuite || sc->server->auth.cipher_suite) && !SSL_set_cipher_list(ssl, dc->szCipherSuite ? dc->szCipherSuite : sc->server->auth.cipher_suite)) { ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(02253) "Unable to reconfigure (per-directory) " "permitted SSL ciphers"); ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, r->server); if (cipher_list_old) { sk_SSL_CIPHER_free(cipher_list_old); } return HTTP_FORBIDDEN; } /* determine whether a renegotiation has to be forced */ cipher_list = (STACK_OF(SSL_CIPHER) *)SSL_get_ciphers(ssl); if (dc->nOptions & SSL_OPT_OPTRENEGOTIATE) { /* optimized way */ if ((!cipher && cipher_list) || (cipher && !cipher_list)) { renegotiate = TRUE; } else if (cipher && cipher_list && (sk_SSL_CIPHER_find(cipher_list, cipher) < 0)) { renegotiate = TRUE; } } else { /* paranoid way */ if ((!cipher_list_old && cipher_list) || (cipher_list_old && !cipher_list)) { renegotiate = TRUE; } else if (cipher_list_old && cipher_list) { for (n = 0; !renegotiate && (n < sk_SSL_CIPHER_num(cipher_list)); n++) { SSL_CIPHER *value = sk_SSL_CIPHER_value(cipher_list, n); if (sk_SSL_CIPHER_find(cipher_list_old, value) < 0) { renegotiate = TRUE; } } for (n = 0; !renegotiate && (n < sk_SSL_CIPHER_num(cipher_list_old)); n++) { SSL_CIPHER *value = sk_SSL_CIPHER_value(cipher_list_old, n); if (sk_SSL_CIPHER_find(cipher_list, value) < 0) { renegotiate = TRUE; } } } } /* cleanup */ if (cipher_list_old) { sk_SSL_CIPHER_free(cipher_list_old); } if (renegotiate) { #ifdef SSL_OP_CIPHER_SERVER_PREFERENCE if (sc->cipher_server_pref == TRUE) { SSL_set_options(ssl, SSL_OP_CIPHER_SERVER_PREFERENCE); } #endif /* tracing */ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02220) "Reconfigured cipher suite will force renegotiation"); } } /* * override of SSLVerifyDepth * * The depth checks are handled by us manually inside the verify callback * function and not by OpenSSL internally (and our function is aware of * both the per-server and per-directory contexts). So we cannot ask * OpenSSL about the currently verify depth. Instead we remember it in our * SSLConnRec attached to the SSL* of OpenSSL. We've to force the * renegotiation if the reconfigured/new verify depth is less than the * currently active/remembered verify depth (because this means more * restriction on the certificate chain). */ n = (sslconn->verify_depth != UNSET) ? sslconn->verify_depth : (mySrvConfig(handshakeserver))->server->auth.verify_depth; /* determine the new depth */ sslconn->verify_depth = (dc->nVerifyDepth != UNSET) ? dc->nVerifyDepth : sc->server->auth.verify_depth; if (sslconn->verify_depth < n) { renegotiate = TRUE; ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02254) "Reduced client verification depth will force " "renegotiation"); } /* * override of SSLVerifyClient * * We force a renegotiation if the reconfigured/new verify type is * stronger than the currently active verify type. * * The order is: none << optional_no_ca << optional << require * * Additionally the following optimization is possible here: When the * currently active verify type is "none" but a client certificate is * already known/present, it's enough to manually force a client * verification but at least skip the I/O-intensive renegotiation * handshake. */ if ((dc->nVerifyClient != SSL_CVERIFY_UNSET) || (sc->server->auth.verify_mode != SSL_CVERIFY_UNSET)) { /* remember old state */ verify_old = SSL_get_verify_mode(ssl); /* configure new state */ verify = SSL_VERIFY_NONE; if ((dc->nVerifyClient == SSL_CVERIFY_REQUIRE) || (sc->server->auth.verify_mode == SSL_CVERIFY_REQUIRE)) { verify |= SSL_VERIFY_PEER_STRICT; } if ((dc->nVerifyClient == SSL_CVERIFY_OPTIONAL) || (dc->nVerifyClient == SSL_CVERIFY_OPTIONAL_NO_CA) || (sc->server->auth.verify_mode == SSL_CVERIFY_OPTIONAL) || (sc->server->auth.verify_mode == SSL_CVERIFY_OPTIONAL_NO_CA)) { verify |= SSL_VERIFY_PEER; } SSL_set_verify(ssl, verify, ssl_callback_SSLVerify); SSL_set_verify_result(ssl, X509_V_OK); /* determine whether we've to force a renegotiation */ if (!renegotiate && verify != verify_old) { if (((verify_old == SSL_VERIFY_NONE) && (verify != SSL_VERIFY_NONE)) || (!(verify_old & SSL_VERIFY_PEER) && (verify & SSL_VERIFY_PEER)) || (!(verify_old & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) && (verify & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))) { renegotiate = TRUE; /* optimization */ if ((dc->nOptions & SSL_OPT_OPTRENEGOTIATE) && (verify_old == SSL_VERIFY_NONE) && ((peercert = SSL_get_peer_certificate(ssl)) != NULL)) { renegotiate_quick = TRUE; X509_free(peercert); } ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02255) "Changed client verification type will force " "%srenegotiation", renegotiate_quick ? "quick " : ""); } } /* If we're handling a request for a vhost other than the default one, * then we need to make sure that client authentication is properly * enforced. For clients supplying an SNI extension, the peer * certificate verification has happened in the handshake already * (and r->server == handshakeserver). For non-SNI requests, * an additional check is needed here. If client authentication * is configured as mandatory, then we can only proceed if the * CA list doesn't have to be changed (OpenSSL doesn't provide * an option to change the list for an existing session). */ if ((r->server != handshakeserver) && renegotiate && ((verify & SSL_VERIFY_PEER) || (verify & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))) { SSLSrvConfigRec *hssc = mySrvConfig(handshakeserver); #define MODSSL_CFG_CA_NE(f, sc1, sc2) \ (sc1->server->auth.f && \ (!sc2->server->auth.f || \ strNE(sc1->server->auth.f, sc2->server->auth.f))) if (MODSSL_CFG_CA_NE(ca_cert_file, sc, hssc) || MODSSL_CFG_CA_NE(ca_cert_path, sc, hssc)) { if (verify & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) { ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02256) "Non-default virtual host with SSLVerify set to " "'require' and VirtualHost-specific CA certificate " "list is only available to clients with TLS server " "name indication (SNI) support"); SSL_set_verify(ssl, verify_old, NULL); return HTTP_FORBIDDEN; } else /* let it pass, possibly with an "incorrect" peer cert, * so make sure the SSL_CLIENT_VERIFY environment variable * will indicate partial success only, later on. */ sslconn->verify_info = "GENEROUS"; } } } /* If a renegotiation is now required for this location, and the * request includes a message body (and the client has not * requested a "100 Continue" response), then the client will be * streaming the request body over the wire already. In that * case, it is not possible to stop and perform a new SSL * handshake immediately; once the SSL library moves to the * "accept" state, it will reject the SSL packets which the client * is sending for the request body. * * To allow authentication to complete in this auth hook, the * solution used here is to fill a (bounded) buffer with the * request body, and then to reinject that request body later. */ if (renegotiate && !renegotiate_quick && (apr_table_get(r->headers_in, "transfer-encoding") || (apr_table_get(r->headers_in, "content-length") && strcmp(apr_table_get(r->headers_in, "content-length"), "0"))) && !r->expecting_100) { int rv; apr_size_t rsize; rsize = dc->nRenegBufferSize == UNSET ? DEFAULT_RENEG_BUFFER_SIZE : dc->nRenegBufferSize; if (rsize > 0) { /* Fill the I/O buffer with the request body if possible. */ rv = ssl_io_buffer_fill(r, rsize); } else { /* If the reneg buffer size is set to zero, just fail. */ rv = HTTP_REQUEST_ENTITY_TOO_LARGE; } if (rv) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02257) "could not buffer message body to allow " "SSL renegotiation to proceed"); return rv; } } /* * now do the renegotiation if anything was actually reconfigured */ if (renegotiate) { /* * Now we force the SSL renegotiation by sending the Hello Request * message to the client. Here we have to do a workaround: Actually * OpenSSL returns immediately after sending the Hello Request (the * intent AFAIK is because the SSL/TLS protocol says it's not a must * that the client replies to a Hello Request). But because we insist * on a reply (anything else is an error for us) we have to go to the * ACCEPT state manually. Using SSL_set_accept_state() doesn't work * here because it resets too much of the connection. So we set the * state explicitly and continue the handshake manually. */ ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02221) "Requesting connection re-negotiation"); if (renegotiate_quick) { STACK_OF(X509) *cert_stack; /* perform just a manual re-verification of the peer */ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02258) "Performing quick renegotiation: " "just re-verifying the peer"); cert_stack = (STACK_OF(X509) *)SSL_get_peer_cert_chain(ssl); cert = SSL_get_peer_certificate(ssl); if (!cert_stack && cert) { /* client cert is in the session cache, but there is * no chain, since ssl3_get_client_certificate() * sk_X509_shift-ed the peer cert out of the chain. * we put it back here for the purpose of quick_renegotiation. */ cert_stack = sk_X509_new_null(); sk_X509_push(cert_stack, cert); } if (!cert_stack || (sk_X509_num(cert_stack) == 0)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02222) "Cannot find peer certificate chain"); return HTTP_FORBIDDEN; } if (!(cert_store || (cert_store = SSL_CTX_get_cert_store(ctx)))) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02223) "Cannot find certificate storage"); return HTTP_FORBIDDEN; } if (!cert) { cert = sk_X509_value(cert_stack, 0); } X509_STORE_CTX_init(&cert_store_ctx, cert_store, cert, cert_stack); depth = SSL_get_verify_depth(ssl); if (depth >= 0) { X509_STORE_CTX_set_depth(&cert_store_ctx, depth); } X509_STORE_CTX_set_ex_data(&cert_store_ctx, SSL_get_ex_data_X509_STORE_CTX_idx(), (char *)ssl); if (!X509_verify_cert(&cert_store_ctx)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02224) "Re-negotiation verification step failed"); ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, r->server); } SSL_set_verify_result(ssl, cert_store_ctx.error); X509_STORE_CTX_cleanup(&cert_store_ctx); if (cert_stack != SSL_get_peer_cert_chain(ssl)) { /* we created this ourselves, so free it */ sk_X509_pop_free(cert_stack, X509_free); } } else { const char *reneg_support; request_rec *id = r->main ? r->main : r; /* Additional mitigation for CVE-2009-3555: At this point, * before renegotiating, an (entire) request has been read * from the connection. An attacker may have sent further * data to "prefix" any subsequent request by the victim's * client after the renegotiation; this data may already * have been read and buffered. Forcing a connection * closure after the response ensures such data will be * discarded. Legimately pipelined HTTP requests will be * retried anyway with this approach. */ if (has_buffered_data(r)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02259) "insecure SSL re-negotiation required, but " "a pipelined request is present; keepalive " "disabled"); r->connection->keepalive = AP_CONN_CLOSE; } #if defined(SSL_get_secure_renegotiation_support) reneg_support = SSL_get_secure_renegotiation_support(ssl) ? "client does" : "client does not"; #else reneg_support = "server does not"; #endif /* Perform a full renegotiation. */ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02260) "Performing full renegotiation: complete handshake " "protocol (%s support secure renegotiation)", reneg_support); SSL_set_session_id_context(ssl, (unsigned char *)&id, sizeof(id)); /* Toggle the renegotiation state to allow the new * handshake to proceed. */ sslconn->reneg_state = RENEG_ALLOW; SSL_renegotiate(ssl); SSL_do_handshake(ssl); if (SSL_get_state(ssl) != SSL_ST_OK) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02225) "Re-negotiation request failed"); ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, r->server); r->connection->keepalive = AP_CONN_CLOSE; return HTTP_FORBIDDEN; } ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02226) "Awaiting re-negotiation handshake"); /* XXX: Should replace setting state with SSL_renegotiate(ssl); * However, this causes failures in perl-framework currently, * perhaps pre-test if we have already negotiated? */ #ifdef OPENSSL_NO_SSL_INTERN SSL_set_state(ssl, SSL_ST_ACCEPT); #else ssl->state = SSL_ST_ACCEPT; #endif SSL_do_handshake(ssl); sslconn->reneg_state = RENEG_REJECT; if (SSL_get_state(ssl) != SSL_ST_OK) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02261) "Re-negotiation handshake failed: " "Not accepted by client!?"); r->connection->keepalive = AP_CONN_CLOSE; return HTTP_FORBIDDEN; } } /* * Remember the peer certificate's DN */ if ((cert = SSL_get_peer_certificate(ssl))) { if (sslconn->client_cert) { X509_free(sslconn->client_cert); } sslconn->client_cert = cert; sslconn->client_dn = NULL; } /* * Finally check for acceptable renegotiation results */ if ((dc->nVerifyClient != SSL_CVERIFY_NONE) || (sc->server->auth.verify_mode != SSL_CVERIFY_NONE)) { BOOL do_verify = ((dc->nVerifyClient == SSL_CVERIFY_REQUIRE) || (sc->server->auth.verify_mode == SSL_CVERIFY_REQUIRE)); if (do_verify && (SSL_get_verify_result(ssl) != X509_V_OK)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02262) "Re-negotiation handshake failed: " "Client verification failed"); return HTTP_FORBIDDEN; } if (do_verify) { if ((peercert = SSL_get_peer_certificate(ssl)) == NULL) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02263) "Re-negotiation handshake failed: " "Client certificate missing"); return HTTP_FORBIDDEN; } X509_free(peercert); } } /* * Also check that SSLCipherSuite has been enforced as expected. */ if (cipher_list) { cipher = SSL_get_current_cipher(ssl); if (sk_SSL_CIPHER_find(cipher_list, cipher) < 0) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02264) "SSL cipher suite not renegotiated: " "access to %s denied using cipher %s", r->filename, SSL_CIPHER_get_name(cipher)); return HTTP_FORBIDDEN; } } } /* If we're trying to have the user name set from a client * certificate then we need to set it here. This should be safe as * the user name probably isn't important from an auth checking point * of view as the certificate supplied acts in that capacity. * However, if FakeAuth is being used then this isn't the case so * we need to postpone setting the username until later. */ if ((dc->nOptions & SSL_OPT_FAKEBASICAUTH) == 0 && dc->szUserName) { char *val = ssl_var_lookup(r->pool, r->server, r->connection, r, (char *)dc->szUserName); if (val && val[0]) r->user = val; else ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(02227) "Failed to set r->user to '%s'", dc->szUserName); } /* * Check SSLRequire boolean expressions */ requires = dc->aRequirement; ssl_requires = (ssl_require_t *)requires->elts; for (i = 0; i < requires->nelts; i++) { ssl_require_t *req = &ssl_requires[i]; const char *errstring; ok = ap_expr_exec(r, req->mpExpr, &errstring); if (ok < 0) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02265) "access to %s failed, reason: Failed to execute " "SSL requirement expression: %s", r->filename, errstring); /* remember forbidden access for strict require option */ apr_table_setn(r->notes, "ssl-access-forbidden", "1"); return HTTP_FORBIDDEN; } if (ok != 1) { ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02266) "Access to %s denied for %s " "(requirement expression not fulfilled)", r->filename, r->useragent_ip); ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02228) "Failed expression: %s", req->cpExpr); ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02229) "access to %s failed, reason: %s", r->filename, "SSL requirement expression not fulfilled"); /* remember forbidden access for strict require option */ apr_table_setn(r->notes, "ssl-access-forbidden", "1"); return HTTP_FORBIDDEN; } } /* * Else access is granted from our point of view (except vendor * handlers override). But we have to return DECLINED here instead * of OK, because mod_auth and other modules still might want to * deny access. */ return DECLINED; } /* * Authentication Handler: * Fake a Basic authentication from the X509 client certificate. * * This must be run fairly early on to prevent a real authentication from * occuring, in particular it must be run before anything else that * authenticates a user. This means that the Module statement for this * module should be LAST in the Configuration file. */ int ssl_hook_UserCheck(request_rec *r) { SSLConnRec *sslconn = myConnConfig(r->connection); SSLSrvConfigRec *sc = mySrvConfig(r->server); SSLDirConfigRec *dc = myDirConfig(r); char *clientdn; const char *auth_line, *username, *password; /* * Additionally forbid access (again) * when strict require option is used. */ if ((dc->nOptions & SSL_OPT_STRICTREQUIRE) && (apr_table_get(r->notes, "ssl-access-forbidden"))) { return HTTP_FORBIDDEN; } /* * We decline when we are in a subrequest. The Authorization header * would already be present if it was added in the main request. */ if (!ap_is_initial_req(r)) { return DECLINED; } /* * Make sure the user is not able to fake the client certificate * based authentication by just entering an X.509 Subject DN * ("/XX=YYY/XX=YYY/..") as the username and "password" as the * password. */ if ((auth_line = apr_table_get(r->headers_in, "Authorization"))) { if (strcEQ(ap_getword(r->pool, &auth_line, ' '), "Basic")) { while ((*auth_line == ' ') || (*auth_line == '\t')) { auth_line++; } auth_line = ap_pbase64decode(r->pool, auth_line); username = ap_getword_nulls(r->pool, &auth_line, ':'); password = auth_line; if ((username[0] == '/') && strEQ(password, "password")) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02035) "Encountered FakeBasicAuth spoof: %s", username); return HTTP_FORBIDDEN; } } } /* * We decline operation in various situations... * - SSLOptions +FakeBasicAuth not configured * - r->user already authenticated * - ssl not enabled * - client did not present a certificate */ if (!((sc->enabled == SSL_ENABLED_TRUE || sc->enabled == SSL_ENABLED_OPTIONAL) && sslconn && sslconn->ssl && sslconn->client_cert) || !(dc->nOptions & SSL_OPT_FAKEBASICAUTH) || r->user) { return DECLINED; } if (!sslconn->client_dn) { X509_NAME *name = X509_get_subject_name(sslconn->client_cert); char *cp = X509_NAME_oneline(name, NULL, 0); sslconn->client_dn = apr_pstrdup(r->connection->pool, cp); OPENSSL_free(cp); } clientdn = (char *)sslconn->client_dn; /* * Fake a password - which one would be immaterial, as, it seems, an empty * password in the users file would match ALL incoming passwords, if only * we were using the standard crypt library routine. Unfortunately, OpenSSL * "fixes" a "bug" in crypt and thus prevents blank passwords from * working. (IMHO what they really fix is a bug in the users of the code * - failing to program correctly for shadow passwords). We need, * therefore, to provide a password. This password can be matched by * adding the string "xxj31ZMTZzkVA" as the password in the user file. * This is just the crypted variant of the word "password" ;-) */ auth_line = apr_pstrcat(r->pool, "Basic ", ap_pbase64encode(r->pool, apr_pstrcat(r->pool, clientdn, ":password", NULL)), NULL); apr_table_setn(r->headers_in, "Authorization", auth_line); ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02036) "Faking HTTP Basic Auth header: \"Authorization: %s\"", auth_line); return DECLINED; } /* authorization phase */ int ssl_hook_Auth(request_rec *r) { SSLDirConfigRec *dc = myDirConfig(r); /* * Additionally forbid access (again) * when strict require option is used. */ if ((dc->nOptions & SSL_OPT_STRICTREQUIRE) && (apr_table_get(r->notes, "ssl-access-forbidden"))) { return HTTP_FORBIDDEN; } return DECLINED; } /* * Fixup Handler */ static const char *ssl_hook_Fixup_vars[] = { "SSL_VERSION_INTERFACE", "SSL_VERSION_LIBRARY", "SSL_PROTOCOL", "SSL_SECURE_RENEG", "SSL_COMPRESS_METHOD", "SSL_CIPHER", "SSL_CIPHER_EXPORT", "SSL_CIPHER_USEKEYSIZE", "SSL_CIPHER_ALGKEYSIZE", "SSL_CLIENT_VERIFY", "SSL_CLIENT_M_VERSION", "SSL_CLIENT_M_SERIAL", "SSL_CLIENT_V_START", "SSL_CLIENT_V_END", "SSL_CLIENT_V_REMAIN", "SSL_CLIENT_S_DN", "SSL_CLIENT_I_DN", "SSL_CLIENT_A_KEY", "SSL_CLIENT_A_SIG", "SSL_SERVER_M_VERSION", "SSL_SERVER_M_SERIAL", "SSL_SERVER_V_START", "SSL_SERVER_V_END", "SSL_SERVER_S_DN", "SSL_SERVER_I_DN", "SSL_SERVER_A_KEY", "SSL_SERVER_A_SIG", "SSL_SESSION_ID", "SSL_SESSION_RESUMED", #ifdef HAVE_SRP "SSL_SRP_USER", "SSL_SRP_USERINFO", #endif NULL }; int ssl_hook_Fixup(request_rec *r) { SSLConnRec *sslconn = myConnConfig(r->connection); SSLSrvConfigRec *sc = mySrvConfig(r->server); SSLDirConfigRec *dc = myDirConfig(r); apr_table_t *env = r->subprocess_env; char *var, *val = ""; #ifdef HAVE_TLSEXT const char *servername; #endif STACK_OF(X509) *peer_certs; SSL *ssl; int i; /* If "SSLEngine optional" is configured, this is not an SSL * connection, and this isn't a subrequest, send an Upgrade * response header. */ if (sc->enabled == SSL_ENABLED_OPTIONAL && !(sslconn && sslconn->ssl) && !r->main) { apr_table_setn(r->headers_out, "Upgrade", "TLS/1.0, HTTP/1.1"); apr_table_mergen(r->headers_out, "Connection", "upgrade"); } /* * Check to see if SSL is on */ if (!(((sc->enabled == SSL_ENABLED_TRUE) || (sc->enabled == SSL_ENABLED_OPTIONAL)) && sslconn && (ssl = sslconn->ssl))) { return DECLINED; } /* * Annotate the SSI/CGI environment with standard SSL information */ /* the always present HTTPS (=HTTP over SSL) flag! */ apr_table_setn(env, "HTTPS", "on"); #ifdef HAVE_TLSEXT /* add content of SNI TLS extension (if supplied with ClientHello) */ if ((servername = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name))) { apr_table_set(env, "SSL_TLS_SNI", servername); } #endif /* standard SSL environment variables */ if (dc->nOptions & SSL_OPT_STDENVVARS) { modssl_var_extract_dns(env, sslconn->ssl, r->pool); for (i = 0; ssl_hook_Fixup_vars[i]; i++) { var = (char *)ssl_hook_Fixup_vars[i]; val = ssl_var_lookup(r->pool, r->server, r->connection, r, var); if (!strIsEmpty(val)) { apr_table_setn(env, var, val); } } } /* * On-demand bloat up the SSI/CGI environment with certificate data */ if (dc->nOptions & SSL_OPT_EXPORTCERTDATA) { val = ssl_var_lookup(r->pool, r->server, r->connection, r, "SSL_SERVER_CERT"); apr_table_setn(env, "SSL_SERVER_CERT", val); val = ssl_var_lookup(r->pool, r->server, r->connection, r, "SSL_CLIENT_CERT"); apr_table_setn(env, "SSL_CLIENT_CERT", val); if ((peer_certs = (STACK_OF(X509) *)SSL_get_peer_cert_chain(ssl))) { for (i = 0; i < sk_X509_num(peer_certs); i++) { var = apr_psprintf(r->pool, "SSL_CLIENT_CERT_CHAIN_%d", i); val = ssl_var_lookup(r->pool, r->server, r->connection, r, var); if (val) { apr_table_setn(env, var, val); } } } } #ifdef SSL_get_secure_renegotiation_support apr_table_setn(r->notes, "ssl-secure-reneg", SSL_get_secure_renegotiation_support(ssl) ? "1" : "0"); #endif return DECLINED; } /* _________________________________________________________________ ** ** Authz providers for use with mod_authz_core ** _________________________________________________________________ */ static authz_status ssl_authz_require_ssl_check(request_rec *r, const char *require_line, const void *parsed) { SSLConnRec *sslconn = myConnConfig(r->connection); SSL *ssl = sslconn ? sslconn->ssl : NULL; if (ssl) return AUTHZ_GRANTED; else return AUTHZ_DENIED; } static const char *ssl_authz_require_ssl_parse(cmd_parms *cmd, const char *require_line, const void **parsed) { if (require_line && require_line[0]) return "'Require ssl' does not take arguments"; return NULL; } const authz_provider ssl_authz_provider_require_ssl = { &ssl_authz_require_ssl_check, &ssl_authz_require_ssl_parse, }; static authz_status ssl_authz_verify_client_check(request_rec *r, const char *require_line, const void *parsed) { SSLConnRec *sslconn = myConnConfig(r->connection); SSL *ssl = sslconn ? sslconn->ssl : NULL; if (!ssl) return AUTHZ_DENIED; if (sslconn->verify_error == NULL && sslconn->verify_info == NULL && SSL_get_verify_result(ssl) == X509_V_OK) { X509 *xs = SSL_get_peer_certificate(ssl); if (xs) { X509_free(xs); return AUTHZ_GRANTED; } else { X509_free(xs); } } return AUTHZ_DENIED; } static const char *ssl_authz_verify_client_parse(cmd_parms *cmd, const char *require_line, const void **parsed) { if (require_line && require_line[0]) return "'Require ssl-verify-client' does not take arguments"; return NULL; } const authz_provider ssl_authz_provider_verify_client = { &ssl_authz_verify_client_check, &ssl_authz_verify_client_parse, }; /* _________________________________________________________________ ** ** OpenSSL Callback Functions ** _________________________________________________________________ */ /* * Hand out standard DH parameters, based on the authentication strength */ DH *ssl_callback_TmpDH(SSL *ssl, int export, int keylen) { conn_rec *c = (conn_rec *)SSL_get_app_data(ssl); EVP_PKEY *pkey; int type; #ifdef SSL_CERT_SET_SERVER /* * When multiple certs/keys are configured for the SSL_CTX: make sure * that we get the private key which is indeed used for the current * SSL connection (available in OpenSSL 1.0.2 or later only) */ SSL_set_current_cert(ssl, SSL_CERT_SET_SERVER); #endif pkey = SSL_get_privatekey(ssl); type = pkey ? EVP_PKEY_type(pkey->type) : EVP_PKEY_NONE; /* * OpenSSL will call us with either keylen == 512 or keylen == 1024 * (see the definition of SSL_EXPORT_PKEYLENGTH in ssl_locl.h). * Adjust the DH parameter length according to the size of the * RSA/DSA private key used for the current connection, and always * use at least 1024-bit parameters. * Note: This may cause interoperability issues with implementations * which limit their DH support to 1024 bit - e.g. Java 7 and earlier. * In this case, SSLCertificateFile can be used to specify fixed * 1024-bit DH parameters (with the effect that OpenSSL skips this * callback). */ if ((type == EVP_PKEY_RSA) || (type == EVP_PKEY_DSA)) { keylen = EVP_PKEY_bits(pkey); } ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c, "handing out built-in DH parameters for %d-bit authenticated connection", keylen); return modssl_get_dh_params(keylen); } /* * This OpenSSL callback function is called when OpenSSL * does client authentication and verifies the certificate chain. */ int ssl_callback_SSLVerify(int ok, X509_STORE_CTX *ctx) { /* Get Apache context back through OpenSSL context */ SSL *ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx()); conn_rec *conn = (conn_rec *)SSL_get_app_data(ssl); request_rec *r = (request_rec *)SSL_get_app_data2(ssl); server_rec *s = r ? r->server : mySrvFromConn(conn); SSLSrvConfigRec *sc = mySrvConfig(s); SSLDirConfigRec *dc = r ? myDirConfig(r) : NULL; SSLConnRec *sslconn = myConnConfig(conn); modssl_ctx_t *mctx = myCtxConfig(sslconn, sc); /* Get verify ingredients */ int errnum = X509_STORE_CTX_get_error(ctx); int errdepth = X509_STORE_CTX_get_error_depth(ctx); int depth, verify; /* * Log verification information */ ssl_log_cxerror(SSLLOG_MARK, APLOG_DEBUG, 0, conn, X509_STORE_CTX_get_current_cert(ctx), APLOGNO(02275) "Certificate Verification, depth %d, " "CRL checking mode: %s", errdepth, mctx->crl_check_mode == SSL_CRLCHECK_CHAIN ? "chain" : (mctx->crl_check_mode == SSL_CRLCHECK_LEAF ? "leaf" : "none")); /* * Check for optionally acceptable non-verifiable issuer situation */ if (dc && (dc->nVerifyClient != SSL_CVERIFY_UNSET)) { verify = dc->nVerifyClient; } else { verify = mctx->auth.verify_mode; } if (verify == SSL_CVERIFY_NONE) { /* * SSLProxyVerify is either not configured or set to "none". * (this callback doesn't happen in the server context if SSLVerify * is not configured or set to "none") */ return TRUE; } if (ssl_verify_error_is_optional(errnum) && (verify == SSL_CVERIFY_OPTIONAL_NO_CA)) { ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, conn, APLOGNO(02037) "Certificate Verification: Verifiable Issuer is " "configured as optional, therefore we're accepting " "the certificate"); sslconn->verify_info = "GENEROUS"; ok = TRUE; } /* * Expired certificates vs. "expired" CRLs: by default, OpenSSL * turns X509_V_ERR_CRL_HAS_EXPIRED into a "certificate_expired(45)" * SSL alert, but that's not really the message we should convey to the * peer (at the very least, it's confusing, and in many cases, it's also * inaccurate, as the certificate itself may very well not have expired * yet). We set the X509_STORE_CTX error to something which OpenSSL's * s3_both.c:ssl_verify_alarm_type() maps to SSL_AD_CERTIFICATE_UNKNOWN, * i.e. the peer will receive a "certificate_unknown(46)" alert. * We do not touch errnum, though, so that later on we will still log * the "real" error, as returned by OpenSSL. */ if (!ok && errnum == X509_V_ERR_CRL_HAS_EXPIRED) { X509_STORE_CTX_set_error(ctx, -1); } #ifndef OPENSSL_NO_OCSP /* * Perform OCSP-based revocation checks */ if (ok && sc->server->ocsp_enabled) { /* If there was an optional verification error, it's not * possible to perform OCSP validation since the issuer may be * missing/untrusted. Fail in that case. */ if (ssl_verify_error_is_optional(errnum)) { X509_STORE_CTX_set_error(ctx, X509_V_ERR_APPLICATION_VERIFICATION); errnum = X509_V_ERR_APPLICATION_VERIFICATION; ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, conn, APLOGNO(02038) "cannot perform OCSP validation for cert " "if issuer has not been verified " "(optional_no_ca configured)"); ok = FALSE; } else { ok = modssl_verify_ocsp(ctx, sc, s, conn, conn->pool); if (!ok) { errnum = X509_STORE_CTX_get_error(ctx); } } } #endif /* * If we already know it's not ok, log the real reason */ if (!ok) { if (APLOGcinfo(conn)) { ssl_log_cxerror(SSLLOG_MARK, APLOG_INFO, 0, conn, X509_STORE_CTX_get_current_cert(ctx), APLOGNO(02276) "Certificate Verification: Error (%d): %s", errnum, X509_verify_cert_error_string(errnum)); } else { ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, conn, APLOGNO(02039) "Certificate Verification: Error (%d): %s", errnum, X509_verify_cert_error_string(errnum)); } if (sslconn->client_cert) { X509_free(sslconn->client_cert); sslconn->client_cert = NULL; } sslconn->client_dn = NULL; sslconn->verify_error = X509_verify_cert_error_string(errnum); } /* * Finally check the depth of the certificate verification */ if (dc && (dc->nVerifyDepth != UNSET)) { depth = dc->nVerifyDepth; } else { depth = mctx->auth.verify_depth; } if (errdepth > depth) { ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, conn, APLOGNO(02040) "Certificate Verification: Certificate Chain too long " "(chain has %d certificates, but maximum allowed are " "only %d)", errdepth, depth); errnum = X509_V_ERR_CERT_CHAIN_TOO_LONG; sslconn->verify_error = X509_verify_cert_error_string(errnum); ok = FALSE; } /* * And finally signal OpenSSL the (perhaps changed) state */ return ok; } #define SSLPROXY_CERT_CB_LOG_FMT \ "Proxy client certificate callback: (%s) " static void modssl_proxy_info_log(conn_rec *c, X509_INFO *info, const char *msg) { ssl_log_cxerror(SSLLOG_MARK, APLOG_DEBUG, 0, c, info->x509, APLOGNO(02277) SSLPROXY_CERT_CB_LOG_FMT "%s, sending", (mySrvConfigFromConn(c))->vhost_id, msg); } /* * caller will decrement the cert and key reference * so we need to increment here to prevent them from * being freed. */ #define modssl_set_cert_info(info, cert, pkey) \ *cert = info->x509; \ CRYPTO_add(&(*cert)->references, +1, CRYPTO_LOCK_X509); \ *pkey = info->x_pkey->dec_pkey; \ CRYPTO_add(&(*pkey)->references, +1, CRYPTO_LOCK_X509_PKEY) int ssl_callback_proxy_cert(SSL *ssl, X509 **x509, EVP_PKEY **pkey) { conn_rec *c = (conn_rec *)SSL_get_app_data(ssl); server_rec *s = mySrvFromConn(c); SSLSrvConfigRec *sc = mySrvConfig(s); X509_NAME *ca_name, *issuer, *ca_issuer; X509_INFO *info; X509 *ca_cert; STACK_OF(X509_NAME) *ca_list; STACK_OF(X509_INFO) *certs = sc->proxy->pkp->certs; STACK_OF(X509) *ca_certs; STACK_OF(X509) **ca_cert_chains; int i, j, k; ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(02267) SSLPROXY_CERT_CB_LOG_FMT "entered", sc->vhost_id); if (!certs || (sk_X509_INFO_num(certs) <= 0)) { ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(02268) SSLPROXY_CERT_CB_LOG_FMT "downstream server wanted client certificate " "but none are configured", sc->vhost_id); return FALSE; } ca_list = SSL_get_client_CA_list(ssl); if (!ca_list || (sk_X509_NAME_num(ca_list) <= 0)) { /* * downstream server didn't send us a list of acceptable CA certs, * so we send the first client cert in the list. */ info = sk_X509_INFO_value(certs, 0); modssl_proxy_info_log(c, info, APLOGNO(02278) "no acceptable CA list"); modssl_set_cert_info(info, x509, pkey); return TRUE; } ca_cert_chains = sc->proxy->pkp->ca_certs; for (i = 0; i < sk_X509_NAME_num(ca_list); i++) { ca_name = sk_X509_NAME_value(ca_list, i); for (j = 0; j < sk_X509_INFO_num(certs); j++) { info = sk_X509_INFO_value(certs, j); issuer = X509_get_issuer_name(info->x509); /* Search certs (by issuer name) one by one*/ if (X509_NAME_cmp(issuer, ca_name) == 0) { modssl_proxy_info_log(c, info, APLOGNO(02279) "found acceptable cert"); modssl_set_cert_info(info, x509, pkey); return TRUE; } if (ca_cert_chains) { /* * Failed to find direct issuer - search intermediates * (by issuer name), if provided. */ ca_certs = ca_cert_chains[j]; for (k = 0; k < sk_X509_num(ca_certs); k++) { ca_cert = sk_X509_value(ca_certs, k); ca_issuer = X509_get_issuer_name(ca_cert); if(X509_NAME_cmp(ca_issuer, ca_name) == 0 ) { modssl_proxy_info_log(c, info, APLOGNO(02280) "found acceptable cert by intermediate CA"); modssl_set_cert_info(info, x509, pkey); return TRUE; } } /* end loop through chained certs */ } } /* end loop through available certs */ } ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(02269) SSLPROXY_CERT_CB_LOG_FMT "no client certificate found!?", sc->vhost_id); return FALSE; } static void ssl_session_log(server_rec *s, const char *request, unsigned char *id, unsigned int idlen, const char *status, const char *result, long timeout) { char buf[SSL_SESSION_ID_STRING_LEN]; char timeout_str[56] = {'\0'}; if (!APLOGdebug(s)) { return; } if (timeout) { apr_snprintf(timeout_str, sizeof(timeout_str), "timeout=%lds ", timeout); } ap_log_error(APLOG_MARK, APLOG_TRACE2, 0, s, "Inter-Process Session Cache: " "request=%s status=%s id=%s %s(session %s)", request, status, SSL_SESSION_id2sz(id, idlen, buf, sizeof(buf)), timeout_str, result); } /* * This callback function is executed by OpenSSL whenever a new SSL_SESSION is * added to the internal OpenSSL session cache. We use this hook to spread the * SSL_SESSION also to the inter-process disk-cache to make share it with our * other Apache pre-forked server processes. */ int ssl_callback_NewSessionCacheEntry(SSL *ssl, SSL_SESSION *session) { /* Get Apache context back through OpenSSL context */ conn_rec *conn = (conn_rec *)SSL_get_app_data(ssl); server_rec *s = mySrvFromConn(conn); SSLSrvConfigRec *sc = mySrvConfig(s); long timeout = sc->session_cache_timeout; BOOL rc; unsigned char *id; unsigned int idlen; /* * Set the timeout also for the internal OpenSSL cache, because this way * our inter-process cache is consulted only when it's really necessary. */ SSL_set_timeout(session, timeout); /* * Store the SSL_SESSION in the inter-process cache with the * same expire time, so it expires automatically there, too. */ #ifdef OPENSSL_NO_SSL_INTERN id = (unsigned char *)SSL_SESSION_get_id(session, &idlen); #else id = session->session_id; idlen = session->session_id_length; #endif rc = ssl_scache_store(s, id, idlen, apr_time_from_sec(SSL_SESSION_get_time(session) + timeout), session, conn->pool); ssl_session_log(s, "SET", id, idlen, rc == TRUE ? "OK" : "BAD", "caching", timeout); /* * return 0 which means to OpenSSL that the session is still * valid and was not freed by us with SSL_SESSION_free(). */ return 0; } /* * This callback function is executed by OpenSSL whenever a * SSL_SESSION is looked up in the internal OpenSSL cache and it * was not found. We use this to lookup the SSL_SESSION in the * inter-process disk-cache where it was perhaps stored by one * of our other Apache pre-forked server processes. */ SSL_SESSION *ssl_callback_GetSessionCacheEntry(SSL *ssl, unsigned char *id, int idlen, int *do_copy) { /* Get Apache context back through OpenSSL context */ conn_rec *conn = (conn_rec *)SSL_get_app_data(ssl); server_rec *s = mySrvFromConn(conn); SSL_SESSION *session; /* * Try to retrieve the SSL_SESSION from the inter-process cache */ session = ssl_scache_retrieve(s, id, idlen, conn->pool); ssl_session_log(s, "GET", id, idlen, session ? "FOUND" : "MISSED", session ? "reuse" : "renewal", 0); /* * Return NULL or the retrieved SSL_SESSION. But indicate (by * setting do_copy to 0) that the reference count on the * SSL_SESSION should not be incremented by the SSL library, * because we will no longer hold a reference to it ourself. */ *do_copy = 0; return session; } /* * This callback function is executed by OpenSSL whenever a * SSL_SESSION is removed from the the internal OpenSSL cache. * We use this to remove the SSL_SESSION in the inter-process * disk-cache, too. */ void ssl_callback_DelSessionCacheEntry(SSL_CTX *ctx, SSL_SESSION *session) { server_rec *s; SSLSrvConfigRec *sc; unsigned char *id; unsigned int idlen; /* * Get Apache context back through OpenSSL context */ if (!(s = (server_rec *)SSL_CTX_get_app_data(ctx))) { return; /* on server shutdown Apache is already gone */ } sc = mySrvConfig(s); /* * Remove the SSL_SESSION from the inter-process cache */ #ifdef OPENSSL_NO_SSL_INTERN id = (unsigned char *)SSL_SESSION_get_id(session, &idlen); #else id = session->session_id; idlen = session->session_id_length; #endif /* TODO: Do we need a temp pool here, or are we always shutting down? */ ssl_scache_remove(s, id, idlen, sc->mc->pPool); ssl_session_log(s, "REM", id, idlen, "OK", "dead", 0); return; } /* Dump debugginfo trace to the log file. */ static void log_tracing_state(const SSL *ssl, conn_rec *c, server_rec *s, int where, int rc) { /* * create the various trace messages */ if (where & SSL_CB_HANDSHAKE_START) { ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, c, "%s: Handshake: start", SSL_LIBRARY_NAME); } else if (where & SSL_CB_HANDSHAKE_DONE) { ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, c, "%s: Handshake: done", SSL_LIBRARY_NAME); } else if (where & SSL_CB_LOOP) { ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, c, "%s: Loop: %s", SSL_LIBRARY_NAME, SSL_state_string_long(ssl)); } else if (where & SSL_CB_READ) { ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, c, "%s: Read: %s", SSL_LIBRARY_NAME, SSL_state_string_long(ssl)); } else if (where & SSL_CB_WRITE) { ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, c, "%s: Write: %s", SSL_LIBRARY_NAME, SSL_state_string_long(ssl)); } else if (where & SSL_CB_ALERT) { char *str = (where & SSL_CB_READ) ? "read" : "write"; ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, c, "%s: Alert: %s:%s:%s", SSL_LIBRARY_NAME, str, SSL_alert_type_string_long(rc), SSL_alert_desc_string_long(rc)); } else if (where & SSL_CB_EXIT) { if (rc == 0) { ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, c, "%s: Exit: failed in %s", SSL_LIBRARY_NAME, SSL_state_string_long(ssl)); } else if (rc < 0) { ap_log_cerror(APLOG_MARK, APLOG_TRACE3, 0, c, "%s: Exit: error in %s", SSL_LIBRARY_NAME, SSL_state_string_long(ssl)); } } /* * Because SSL renegotiations can happen at any time (not only after * SSL_accept()), the best way to log the current connection details is * right after a finished handshake. */ if (where & SSL_CB_HANDSHAKE_DONE) { ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(02041) "Protocol: %s, Cipher: %s (%s/%s bits)", ssl_var_lookup(NULL, s, c, NULL, "SSL_PROTOCOL"), ssl_var_lookup(NULL, s, c, NULL, "SSL_CIPHER"), ssl_var_lookup(NULL, s, c, NULL, "SSL_CIPHER_USEKEYSIZE"), ssl_var_lookup(NULL, s, c, NULL, "SSL_CIPHER_ALGKEYSIZE")); } } /* * 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. */ void ssl_callback_Info(const SSL *ssl, int where, int rc) { conn_rec *c; server_rec *s; SSLConnRec *scr; /* Retrieve the conn_rec and the associated SSLConnRec. */ if ((c = (conn_rec *)SSL_get_app_data((SSL *)ssl)) == NULL) { return; } if ((scr = myConnConfig(c)) == NULL) { return; } /* If the reneg state is to reject renegotiations, check the SSL * state machine and move to ABORT if a Client Hello is being * read. */ if ((where & SSL_CB_ACCEPT_LOOP) && scr->reneg_state == RENEG_REJECT) { int state = SSL_get_state((SSL *)ssl); if (state == SSL3_ST_SR_CLNT_HELLO_A || state == SSL23_ST_SR_CLNT_HELLO_A) { scr->reneg_state = RENEG_ABORT; ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(02042) "rejecting client initiated renegotiation"); } } /* If the first handshake is complete, change state to reject any * subsequent client-initiated renegotiation. */ else if ((where & SSL_CB_HANDSHAKE_DONE) && scr->reneg_state == RENEG_INIT) { scr->reneg_state = RENEG_REJECT; } s = mySrvFromConn(c); if (s && APLOGdebug(s)) { log_tracing_state(ssl, c, s, where, rc); } } #ifdef HAVE_TLSEXT /* * This callback function is executed when OpenSSL encounters an extended * client hello with a server name indication extension ("SNI", cf. RFC 6066). */ int ssl_callback_ServerNameIndication(SSL *ssl, int *al, modssl_ctx_t *mctx) { const char *servername = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name); conn_rec *c = (conn_rec *)SSL_get_app_data(ssl); if (c) { if (servername) { if (ap_vhost_iterate_given_conn(c, ssl_find_vhost, (void *)servername)) { ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(02043) "SSL virtual host for servername %s found", servername); return SSL_TLSEXT_ERR_OK; } else { ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(02044) "No matching SSL virtual host for servername " "%s found (using default/first virtual host)", servername); /* * RFC 6066 section 3 says "It is NOT RECOMMENDED to send * a warning-level unrecognized_name(112) alert, because * the client's behavior in response to warning-level alerts * is unpredictable." * * To maintain backwards compatibility in mod_ssl, we * no longer send any alert (neither warning- nor fatal-level), * i.e. we take the second action suggested in RFC 6066: * "If the server understood the ClientHello extension but * does not recognize the server name, the server SHOULD take * one of two actions: either abort the handshake by sending * a fatal-level unrecognized_name(112) alert or continue * the handshake." */ } } else { ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(02645) "Server name not provided via TLS extension " "(using default/first virtual host)"); } } return SSL_TLSEXT_ERR_NOACK; } /* * Find a (name-based) SSL virtual host where either the ServerName * or one of the ServerAliases matches the supplied name (to be used * with ap_vhost_iterate_given_conn()) */ static int ssl_find_vhost(void *servername, conn_rec *c, server_rec *s) { SSLSrvConfigRec *sc; SSL *ssl; BOOL found = FALSE; apr_array_header_t *names; int i; SSLConnRec *sslcon; /* check ServerName */ if (!strcasecmp(servername, s->server_hostname)) { found = TRUE; } /* * if not matched yet, check ServerAlias entries * (adapted from vhost.c:matches_aliases()) */ if (!found) { names = s->names; if (names) { char **name = (char **)names->elts; for (i = 0; i < names->nelts; ++i) { if (!name[i]) continue; if (!strcasecmp(servername, name[i])) { found = TRUE; break; } } } } /* if still no match, check ServerAlias entries with wildcards */ if (!found) { names = s->wild_names; if (names) { char **name = (char **)names->elts; for (i = 0; i < names->nelts; ++i) { if (!name[i]) continue; if (!ap_strcasecmp_match(servername, name[i])) { found = TRUE; break; } } } } /* set SSL_CTX (if matched) */ sslcon = myConnConfig(c); if (found && (ssl = sslcon->ssl) && (sc = mySrvConfig(s))) { SSL_CTX *ctx = SSL_set_SSL_CTX(ssl, sc->server->ssl_ctx); /* * SSL_set_SSL_CTX() only deals with the server cert, * so we need to duplicate a few additional settings * from the ctx by hand */ SSL_set_options(ssl, SSL_CTX_get_options(ctx)); if ((SSL_get_verify_mode(ssl) == SSL_VERIFY_NONE) || (SSL_num_renegotiations(ssl) == 0)) { /* * Only initialize the verification settings from the ctx * if they are not yet set, or if we're called when a new * SSL connection is set up (num_renegotiations == 0). * Otherwise, we would possibly reset a per-directory * configuration which was put into effect by ssl_hook_Access. */ SSL_set_verify(ssl, SSL_CTX_get_verify_mode(ctx), SSL_CTX_get_verify_callback(ctx)); } /* * Adjust the session id context. ssl_init_ssl_connection() * always picks the configuration of the first vhost when * calling SSL_new(), but we want to tie the session to the * vhost we have just switched to. Again, we have to make sure * that we're not overwriting a session id context which was * possibly set in ssl_hook_Access(), before triggering * a renegotiation. */ if (SSL_num_renegotiations(ssl) == 0) { unsigned char *sid_ctx = (unsigned char *)ap_md5_binary(c->pool, (unsigned char *)sc->vhost_id, sc->vhost_id_len); SSL_set_session_id_context(ssl, sid_ctx, APR_MD5_DIGESTSIZE*2); } /* * Save the found server into our SSLConnRec for later * retrieval */ sslcon->server = s; /* * There is one special filter callback, which is set * very early depending on the base_server's log level. * If this is not the first vhost we're now selecting * (and the first vhost doesn't use APLOG_TRACE4), then * we need to set that callback here. */ if (APLOGtrace4(s)) { BIO_set_callback(SSL_get_rbio(ssl), ssl_io_data_cb); BIO_set_callback_arg(SSL_get_rbio(ssl), (void *)ssl); } return 1; } return 0; } #endif /* HAVE_TLSEXT */ #ifdef HAVE_TLS_SESSION_TICKETS /* * This callback function is executed when OpenSSL needs a key for encrypting/ * decrypting a TLS session ticket (RFC 5077) and a ticket key file has been * configured through SSLSessionTicketKeyFile. */ int ssl_callback_SessionTicket(SSL *ssl, unsigned char *keyname, unsigned char *iv, EVP_CIPHER_CTX *cipher_ctx, HMAC_CTX *hctx, int mode) { conn_rec *c = (conn_rec *)SSL_get_app_data(ssl); server_rec *s = mySrvFromConn(c); SSLSrvConfigRec *sc = mySrvConfig(s); SSLConnRec *sslconn = myConnConfig(c); modssl_ctx_t *mctx = myCtxConfig(sslconn, sc); modssl_ticket_key_t *ticket_key = mctx->ticket_key; if (mode == 1) { /* * OpenSSL is asking for a key for encrypting a ticket, * see s3_srvr.c:ssl3_send_newsession_ticket() */ if (ticket_key == NULL) { /* should never happen, but better safe than sorry */ return -1; } memcpy(keyname, ticket_key->key_name, 16); RAND_pseudo_bytes(iv, EVP_MAX_IV_LENGTH); EVP_EncryptInit_ex(cipher_ctx, EVP_aes_128_cbc(), NULL, ticket_key->aes_key, iv); HMAC_Init_ex(hctx, ticket_key->hmac_secret, 16, tlsext_tick_md(), NULL); ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(02289) "TLS session ticket key for %s successfully set, " "creating new session ticket", sc->vhost_id); return 0; } else if (mode == 0) { /* * OpenSSL is asking for the decryption key, * see t1_lib.c:tls_decrypt_ticket() */ /* check key name */ if (ticket_key == NULL || memcmp(keyname, ticket_key->key_name, 16)) { return 0; } EVP_DecryptInit_ex(cipher_ctx, EVP_aes_128_cbc(), NULL, ticket_key->aes_key, iv); HMAC_Init_ex(hctx, ticket_key->hmac_secret, 16, tlsext_tick_md(), NULL); ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(02290) "TLS session ticket key for %s successfully set, " "decrypting existing session ticket", sc->vhost_id); return 1; } /* OpenSSL is not expected to call us with modes other than 1 or 0 */ return -1; } #endif /* HAVE_TLS_SESSION_TICKETS */ #ifdef HAVE_SRP int ssl_callback_SRPServerParams(SSL *ssl, int *ad, void *arg) { modssl_ctx_t *mctx = (modssl_ctx_t *)arg; char *username = SSL_get_srp_username(ssl); SRP_user_pwd *u; if (username == NULL || (u = SRP_VBASE_get_by_user(mctx->srp_vbase, username)) == NULL) { *ad = SSL_AD_UNKNOWN_PSK_IDENTITY; return SSL3_AL_FATAL; } if (SSL_set_srp_server_param(ssl, u->N, u->g, u->s, u->v, u->info) < 0) { *ad = SSL_AD_INTERNAL_ERROR; return SSL3_AL_FATAL; } /* reset all other options */ SSL_set_verify(ssl, SSL_VERIFY_NONE, ssl_callback_SSLVerify); return SSL_ERROR_NONE; } #endif /* HAVE_SRP */