}
static const char ssl_io_filter[] = "SSL/TLS Filter";
+static const char ssl_io_buffer[] = "SSL/TLS Buffer";
/*
* Close the SSL part of the socket connection
return status;
}
+/* 128K maximum buffer size by default. */
+#ifndef SSL_MAX_IO_BUFFER
+#define SSL_MAX_IO_BUFFER (128 * 1024)
+#endif
+
+struct modssl_buffer_ctx {
+ apr_bucket_brigade *bb;
+ apr_pool_t *pool;
+};
+
+int ssl_io_buffer_fill(request_rec *r)
+{
+ conn_rec *c = r->connection;
+ struct modssl_buffer_ctx *ctx;
+ apr_bucket_brigade *tempb;
+ apr_off_t total = 0; /* total length buffered */
+ int eos = 0; /* non-zero once EOS is seen */
+
+ /* Create the context which will be passed to the input filter;
+ * containing a setaside pool and a brigade which constrain the
+ * lifetime of the buffered data. */
+ ctx = apr_palloc(r->pool, sizeof *ctx);
+ apr_pool_create(&ctx->pool, r->pool);
+ ctx->bb = apr_brigade_create(ctx->pool, c->bucket_alloc);
+
+ /* ... and a temporary brigade. */
+ tempb = apr_brigade_create(r->pool, c->bucket_alloc);
+
+ ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, "filling buffer");
+
+ do {
+ apr_status_t rv;
+ apr_bucket *e, *next;
+
+ /* The request body is read from the protocol-level input
+ * filters; the buffering filter will reinject it from that
+ * level, allowing content/resource filters to run later, if
+ * necessary. */
+
+ rv = ap_get_brigade(r->proto_input_filters, tempb, AP_MODE_READBYTES,
+ APR_BLOCK_READ, 8192);
+ if (rv) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
+ "could not read request body for SSL buffer");
+ return HTTP_INTERNAL_SERVER_ERROR;
+ }
+
+ /* Iterate through the returned brigade: setaside each bucket
+ * into the context's pool and move it into the brigade. */
+ for (e = APR_BRIGADE_FIRST(tempb);
+ e != APR_BRIGADE_SENTINEL(tempb) && !eos; e = next) {
+ const char *data;
+ apr_size_t len;
+
+ next = APR_BUCKET_NEXT(e);
+
+ if (APR_BUCKET_IS_EOS(e)) {
+ eos = 1;
+ } else if (!APR_BUCKET_IS_METADATA(e)) {
+ rv = apr_bucket_read(e, &data, &len, APR_BLOCK_READ);
+ if (rv != APR_SUCCESS) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
+ "could not read bucket for SSL buffer");
+ return HTTP_INTERNAL_SERVER_ERROR;
+ }
+ total += len;
+ }
+
+ rv = apr_bucket_setaside(e, ctx->pool);
+ if (rv != APR_SUCCESS) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
+ "could not setaside bucket for SSL buffer");
+ return HTTP_INTERNAL_SERVER_ERROR;
+ }
+
+ APR_BUCKET_REMOVE(e);
+ APR_BRIGADE_INSERT_TAIL(ctx->bb, e);
+ }
+
+ ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c,
+ "total of %" APR_OFF_T_FMT " bytes in buffer, eos=%d",
+ total, eos);
+
+ /* Fail if this exceeds the maximum buffer size. */
+ if (total > SSL_MAX_IO_BUFFER) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+ "request body exceeds maximum size for SSL buffer");
+ return HTTP_REQUEST_ENTITY_TOO_LARGE;
+ }
+
+ } while (!eos);
+
+ apr_brigade_destroy(tempb);
+
+ /* Insert the filter which will supply the buffered data. */
+ ap_add_input_filter(ssl_io_buffer, ctx, r, c);
+
+ return 0;
+}
+
+/* This input filter supplies the buffered request body to the caller
+ * from the brigade stored in f->ctx. */
+static apr_status_t ssl_io_filter_buffer(ap_filter_t *f,
+ apr_bucket_brigade *bb,
+ ap_input_mode_t mode,
+ apr_read_type_e block,
+ apr_off_t bytes)
+{
+ struct modssl_buffer_ctx *ctx = f->ctx;
+ apr_status_t rv;
+
+ ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, f->c,
+ "read from buffered SSL brigade, mode %d, "
+ "%" APR_OFF_T_FMT " bytes",
+ mode, bytes);
+
+ if (mode != AP_MODE_READBYTES && mode != AP_MODE_GETLINE) {
+ return APR_ENOTIMPL;
+ }
+
+ if (mode == AP_MODE_READBYTES) {
+ apr_bucket *e;
+
+ /* Partition the buffered brigade. */
+ rv = apr_brigade_partition(ctx->bb, bytes, &e);
+ if (rv && rv != APR_INCOMPLETE) {
+ ap_log_cerror(APLOG_MARK, APLOG_ERR, rv, f->c,
+ "could not partition buffered SSL brigade");
+ ap_remove_input_filter(f);
+ return rv;
+ }
+
+ /* If the buffered brigade contains less then the requested
+ * length, just pass it all back. */
+ if (rv == APR_INCOMPLETE) {
+ APR_BRIGADE_CONCAT(bb, ctx->bb);
+ } else {
+ apr_bucket *d = APR_BRIGADE_FIRST(ctx->bb);
+
+ e = APR_BUCKET_PREV(e);
+
+ /* Unsplice the partitioned segment and move it into the
+ * passed-in brigade; no convenient way to do this with
+ * the APR_BRIGADE_* macros. */
+ APR_RING_UNSPLICE(d, e, link);
+ APR_RING_SPLICE_HEAD(&bb->list, d, e, apr_bucket, link);
+
+ APR_BRIGADE_CHECK_CONSISTENCY(bb);
+ APR_BRIGADE_CHECK_CONSISTENCY(ctx->bb);
+ }
+ }
+ else {
+ /* Split a line into the passed-in brigade. */
+ rv = apr_brigade_split_line(bb, ctx->bb, mode, bytes);
+
+ if (rv) {
+ ap_log_cerror(APLOG_MARK, APLOG_ERR, rv, f->c,
+ "could not split line from buffered SSL brigade");
+ ap_remove_input_filter(f);
+ return rv;
+ }
+ }
+
+ if (APR_BRIGADE_EMPTY(ctx->bb)) {
+ apr_bucket *e = APR_BRIGADE_LAST(bb);
+
+ /* Ensure that the brigade is terminated by an EOS if the
+ * buffered request body has been entirely consumed. */
+ if (e == APR_BRIGADE_SENTINEL(bb) || !APR_BUCKET_IS_EOS(e)) {
+ e = apr_bucket_eos_create(f->c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(bb, e);
+ }
+
+ ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, f->c,
+ "buffered SSL brigade now exhausted; removing filter");
+ ap_remove_input_filter(f);
+ }
+
+ return APR_SUCCESS;
+}
+
static void ssl_io_input_add_filter(ssl_filter_ctx_t *filter_ctx, conn_rec *c,
SSL *ssl)
{
ap_register_input_filter (ssl_io_filter, ssl_io_filter_input, NULL, AP_FTYPE_CONNECTION + 5);
ap_register_output_filter (ssl_io_filter, ssl_io_filter_output, NULL, AP_FTYPE_CONNECTION + 5);
+
+ ap_register_input_filter (ssl_io_buffer, ssl_io_filter_buffer, NULL, AP_FTYPE_PROTOCOL - 1);
+
return;
}
}
#endif /* HAVE_SSL_SET_CERT_STORE */
- /*
- * SSL renegotiations in conjunction with HTTP
- * requests using the POST method are not supported.
- *
- * Background:
- *
- * 1. When the client sends a HTTP/HTTPS request, Apache's core code
- * reads only the request line ("METHOD /path HTTP/x.y") and the
- * attached MIME headers ("Foo: bar") up to the terminating line ("CR
- * LF"). An attached request body (for instance the data of a POST
- * method) is _NOT_ read. Instead it is read by mod_cgi's content
- * handler and directly passed to the CGI script.
- *
- * 2. mod_ssl supports per-directory re-configuration of SSL parameters.
- * This is implemented by performing an SSL renegotiation of the
- * re-configured parameters after the request is read, but before the
- * response is sent. In more detail: the renegotiation happens after the
- * request line and MIME headers were read, but _before_ the attached
- * request body is read. The reason simply is that in the HTTP protocol
- * usually there is no acknowledgment step between the headers and the
- * body (there is the 100-continue feature and the chunking facility
- * only), so Apache has no API hook for this step.
- *
- * 3. the problem now occurs when the client sends a POST request for
- * URL /foo via HTTPS the server and the server has SSL parameters
- * re-configured on a per-URL basis for /foo. Then mod_ssl has to
- * perform an SSL renegotiation after the request was read and before
- * the response is sent. But the problem is the pending POST body data
- * in the receive buffer of SSL (which Apache still has not read - it's
- * pending until mod_cgi sucks it in). When mod_ssl now tries to perform
- * the renegotiation the pending data leads to an I/O error.
- *
- * Solution Idea:
- *
- * There are only two solutions: Either to simply state that POST
- * requests to URLs with SSL re-configurations are not allowed, or to
- * renegotiate really after the _complete_ request (i.e. including
- * the POST body) was read. Obviously the latter would be preferred,
- * but it cannot be done easily inside Apache, because as already
- * mentioned, there is no API step between the body reading and the body
- * processing. And even when we mod_ssl would hook directly into the
- * loop of mod_cgi, we wouldn't solve the problem for other handlers, of
- * course. So the only general solution is to suck in the pending data
- * of the request body from the OpenSSL BIO into the Apache BUFF. Then
- * the renegotiation can be done and after this step Apache can proceed
- * processing the request as before.
- *
- * Solution Implementation:
- *
- * We cannot simply suck in the data via an SSL_read-based loop because of
- * HTTP chunking. Instead we _have_ to use the Apache API for this step which
- * is aware of HTTP chunking. So the trick is to suck in the pending request
- * data via the Apache API (which uses Apache's BUFF code and in the
- * background mod_ssl's I/O glue code) and re-inject it later into the Apache
- * BUFF code again. This way the data flows twice through the Apache BUFF, of
- * course. But this way the solution doesn't depend on any Apache specifics
- * and is fully transparent to Apache modules.
- *
- * !! BUT ALL THIS IS STILL NOT RE-IMPLEMENTED FOR APACHE 2.0 !!
+ /* 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 && (r->method_number == M_POST)) {
- ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
- "SSL Re-negotiation in conjunction "
- "with POST method not supported! "
- "hint: try SSLOptions +OptRenegotiate");
-
- return HTTP_METHOD_NOT_ALLOWED;
+ 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;
+
+ /* Fill the I/O buffer with the request body if possible. */
+ rv = ssl_io_buffer_fill(r);
+
+ if (rv) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+ "could not buffer message body to allow "
+ "SSL renegotiation to proceed");
+ return rv;
+ }
}
/*