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ssl_engine_kernel.c
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ssl_engine_kernel.c
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/* 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 "mod_ssl.h"
#include "util_md5.h"
static void ssl_configure_env(request_rec *r, SSLConnRec *sslconn);
#ifndef OPENSSL_NO_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;
#ifndef OPENSSL_NO_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.<br />\n Instead use the HTTPS scheme to "
"access this URL, please.<br />\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;
}
#ifndef OPENSSL_NO_TLSEXT
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.
*/
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 wether this strict checking was setup 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");
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;
}
#ifndef OPENSSL_NO_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 *user;
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;