--- modules/ssl/ssl_engine_io.c (revision 291000) +++ modules/ssl/ssl_engine_io.c (working copy) @@ -880,6 +880,7 @@ } 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 @@ -1373,6 +1374,187 @@ 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_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "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_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, + "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_rerror(APLOG_MARK, APLOG_DEBUG, 0, f->r, + "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_rerror(APLOG_MARK, APLOG_ERR, rv, f->r, + "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_rerror(APLOG_MARK, APLOG_ERR, rv, f->r, + "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_rerror(APLOG_MARK, APLOG_DEBUG, 0, f->r, + "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) { @@ -1429,6 +1611,9 @@ { 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; } --- modules/ssl/ssl_engine_kernel.c (revision 291000) +++ modules/ssl/ssl_engine_kernel.c (working copy) @@ -490,73 +490,35 @@ } #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"); + 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; - return HTTP_METHOD_NOT_ALLOWED; + /* 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; + } } /* --- modules/ssl/mod_ssl.h (revision 291000) +++ modules/ssl/mod_ssl.h (working copy) @@ -683,6 +683,10 @@ void ssl_io_filter_register(apr_pool_t *); long ssl_io_data_cb(BIO *, int, MODSSL_BIO_CB_ARG_TYPE *, int, long, long); +/* ssl_io_buffer_fill fills the setaside buffering of the HTTP request + * to allow an SSL renegotiation to take place. */ +int ssl_io_buffer_fill(request_rec *r); + /* PRNG */ int ssl_rand_seed(server_rec *, apr_pool_t *, ssl_rsctx_t, char *);