/* Copyright 2001-2005 The Apache Software Foundation or its licensors, as * applicable. * * Licensed 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_io.c * I/O Functions */ /* ``MY HACK: This universe. Just one little problem: core keeps dumping.'' -- Unknown */ #include "ssl_private.h" /* _________________________________________________________________ ** ** I/O Hooks ** _________________________________________________________________ */ /* This file is designed to be the bridge between OpenSSL and httpd. * However, we really don't expect anyone (let alone ourselves) to * remember what is in this file. So, first, a quick overview. * * In this file, you will find: * - ssl_io_filter_input (Apache input filter) * - ssl_io_filter_output (Apache output filter) * * - bio_filter_in_* (OpenSSL input filter) * - bio_filter_out_* (OpenSSL output filter) * * The input chain is roughly: * * ssl_io_filter_input->ssl_io_input_read->SSL_read->... * ...->bio_filter_in_read->ap_get_brigade/next-httpd-filter * * In mortal terminology, we do the following: * - Receive a request for data to the SSL input filter * - Call a helper function once we know we should perform a read * - Call OpenSSL's SSL_read() * - SSL_read() will then call bio_filter_in_read * - bio_filter_in_read will then try to fetch data from the next httpd filter * - bio_filter_in_read will flatten that data and return it to SSL_read * - SSL_read will then decrypt the data * - ssl_io_input_read will then receive decrypted data as a char* and * ensure that there were no read errors * - The char* is placed in a brigade and returned * * Since connection-level input filters in httpd need to be able to * handle AP_MODE_GETLINE calls (namely identifying LF-terminated strings), * ssl_io_input_getline which will handle this special case. * * Due to AP_MODE_GETLINE and AP_MODE_SPECULATIVE, we may sometimes have * 'leftover' decoded data which must be setaside for the next read. That * is currently handled by the char_buffer_{read|write} functions. So, * ssl_io_input_read may be able to fulfill reads without invoking * SSL_read(). * * Note that the filter context of ssl_io_filter_input and bio_filter_in_* * are shared as bio_filter_in_ctx_t. * * Note that the filter is by choice limited to reading at most * AP_IOBUFSIZE (8192 bytes) per call. * */ /* this custom BIO allows us to hook SSL_write directly into * an apr_bucket_brigade and use transient buckets with the SSL * malloc-ed buffer, rather than copying into a mem BIO. * also allows us to pass the brigade as data is being written * rather than buffering up the entire response in the mem BIO. * * when SSL needs to flush (e.g. SSL_accept()), it will call BIO_flush() * which will trigger a call to bio_filter_out_ctrl() -> bio_filter_out_flush(). * so we only need to flush the output ourselves if we receive an * EOS or FLUSH bucket. this was not possible with the mem BIO where we * had to flush all over the place not really knowing when it was required * to do so. */ typedef struct { SSL *pssl; BIO *pbioRead; BIO *pbioWrite; ap_filter_t *pInputFilter; ap_filter_t *pOutputFilter; int nobuffer; /* non-zero to prevent buffering */ } ssl_filter_ctx_t; typedef struct { ssl_filter_ctx_t *filter_ctx; conn_rec *c; apr_bucket_brigade *bb; apr_size_t length; char buffer[AP_IOBUFSIZE]; apr_size_t blen; apr_status_t rc; } bio_filter_out_ctx_t; static bio_filter_out_ctx_t *bio_filter_out_ctx_new(ssl_filter_ctx_t *filter_ctx, conn_rec *c) { bio_filter_out_ctx_t *outctx = apr_palloc(c->pool, sizeof(*outctx)); outctx->filter_ctx = filter_ctx; outctx->c = c; outctx->bb = apr_brigade_create(c->pool, c->bucket_alloc); outctx->blen = 0; outctx->length = 0; return outctx; } static int bio_filter_out_flush(BIO *bio) { bio_filter_out_ctx_t *outctx = (bio_filter_out_ctx_t *)(bio->ptr); apr_bucket *e; if (!(outctx->blen || outctx->length)) { outctx->rc = APR_SUCCESS; return 1; } if (outctx->blen) { e = apr_bucket_transient_create(outctx->buffer, outctx->blen, outctx->bb->bucket_alloc); /* we filled this buffer first so add it to the * head of the brigade */ APR_BRIGADE_INSERT_HEAD(outctx->bb, e); outctx->blen = 0; } outctx->length = 0; e = apr_bucket_flush_create(outctx->bb->bucket_alloc); APR_BRIGADE_INSERT_TAIL(outctx->bb, e); outctx->rc = ap_pass_brigade(outctx->filter_ctx->pOutputFilter->next, outctx->bb); /* Fail if the connection was reset: */ if (outctx->rc == APR_SUCCESS && outctx->c->aborted) { outctx->rc = APR_ECONNRESET; } return (outctx->rc == APR_SUCCESS) ? 1 : -1; } static int bio_filter_create(BIO *bio) { bio->shutdown = 1; bio->init = 1; bio->num = -1; bio->ptr = NULL; return 1; } static int bio_filter_destroy(BIO *bio) { if (bio == NULL) { return 0; } /* nothing to free here. * apache will destroy the bucket brigade for us */ return 1; } static int bio_filter_out_read(BIO *bio, char *out, int outl) { /* this is never called */ return -1; } static int bio_filter_out_write(BIO *bio, const char *in, int inl) { bio_filter_out_ctx_t *outctx = (bio_filter_out_ctx_t *)(bio->ptr); /* when handshaking we'll have a small number of bytes. * max size SSL will pass us here is about 16k. * (16413 bytes to be exact) */ BIO_clear_retry_flags(bio); if (!outctx->length && (inl + outctx->blen < sizeof(outctx->buffer)) && !outctx->filter_ctx->nobuffer) { /* the first two SSL_writes (of 1024 and 261 bytes) * need to be in the same packet (vec[0].iov_base) */ /* XXX: could use apr_brigade_write() to make code look cleaner * but this way we avoid the malloc(APR_BUCKET_BUFF_SIZE) * and free() of it later */ memcpy(&outctx->buffer[outctx->blen], in, inl); outctx->blen += inl; } else { /* pass along the encrypted data * need to flush since we're using SSL's malloc-ed buffer * which will be overwritten once we leave here */ apr_bucket *bucket = apr_bucket_transient_create(in, inl, outctx->bb->bucket_alloc); outctx->length += inl; APR_BRIGADE_INSERT_TAIL(outctx->bb, bucket); if (bio_filter_out_flush(bio) < 0) { return -1; } } return inl; } static long bio_filter_out_ctrl(BIO *bio, int cmd, long num, void *ptr) { long ret = 1; char **pptr; bio_filter_out_ctx_t *outctx = (bio_filter_out_ctx_t *)(bio->ptr); switch (cmd) { case BIO_CTRL_RESET: outctx->blen = outctx->length = 0; break; case BIO_CTRL_EOF: ret = (long)((outctx->blen + outctx->length) == 0); break; case BIO_C_SET_BUF_MEM_EOF_RETURN: outctx->blen = outctx->length = (apr_size_t)num; break; case BIO_CTRL_INFO: ret = (long)(outctx->blen + outctx->length); if (ptr) { pptr = (char **)ptr; *pptr = (char *)&(outctx->buffer[0]); } break; case BIO_CTRL_GET_CLOSE: ret = (long)bio->shutdown; break; case BIO_CTRL_SET_CLOSE: bio->shutdown = (int)num; break; case BIO_CTRL_WPENDING: ret = 0L; break; case BIO_CTRL_PENDING: ret = (long)(outctx->blen + outctx->length); break; case BIO_CTRL_FLUSH: ret = bio_filter_out_flush(bio); break; case BIO_CTRL_DUP: ret = 1; break; /* N/A */ case BIO_C_SET_BUF_MEM: case BIO_C_GET_BUF_MEM_PTR: /* we don't care */ case BIO_CTRL_PUSH: case BIO_CTRL_POP: default: ret = 0; break; } return ret; } static int bio_filter_out_gets(BIO *bio, char *buf, int size) { /* this is never called */ return -1; } static int bio_filter_out_puts(BIO *bio, const char *str) { /* this is never called */ return -1; } static BIO_METHOD bio_filter_out_method = { BIO_TYPE_MEM, "APR output filter", bio_filter_out_write, bio_filter_out_read, /* read is never called */ bio_filter_out_puts, /* puts is never called */ bio_filter_out_gets, /* gets is never called */ bio_filter_out_ctrl, bio_filter_create, bio_filter_destroy, #ifdef OPENSSL_VERSION_NUMBER NULL /* sslc does not have the callback_ctrl field */ #endif }; typedef struct { int length; char *value; } char_buffer_t; typedef struct { SSL *ssl; BIO *bio_out; ap_filter_t *f; apr_status_t rc; ap_input_mode_t mode; apr_read_type_e block; apr_bucket_brigade *bb; char_buffer_t cbuf; apr_pool_t *pool; char buffer[AP_IOBUFSIZE]; ssl_filter_ctx_t *filter_ctx; } bio_filter_in_ctx_t; /* * this char_buffer api might seem silly, but we don't need to copy * any of this data and we need to remember the length. */ static int char_buffer_read(char_buffer_t *buffer, char *in, int inl) { if (!buffer->length) { return 0; } if (buffer->length > inl) { /* we have have enough to fill the caller's buffer */ memcpy(in, buffer->value, inl); buffer->value += inl; buffer->length -= inl; } else { /* swallow remainder of the buffer */ memcpy(in, buffer->value, buffer->length); inl = buffer->length; buffer->value = NULL; buffer->length = 0; } return inl; } static int char_buffer_write(char_buffer_t *buffer, char *in, int inl) { buffer->value = in; buffer->length = inl; return inl; } /* This function will read from a brigade and discard the read buckets as it * proceeds. It will read at most *len bytes. */ static apr_status_t brigade_consume(apr_bucket_brigade *bb, apr_read_type_e block, char *c, apr_size_t *len) { apr_size_t actual = 0; apr_status_t status = APR_SUCCESS; while (!APR_BRIGADE_EMPTY(bb)) { apr_bucket *b = APR_BRIGADE_FIRST(bb); const char *str; apr_size_t str_len; apr_size_t consume; /* Justin points out this is an http-ism that might * not fit if brigade_consume is added to APR. Perhaps * apr_bucket_read(eos_bucket) should return APR_EOF? * Then this becomes mainline instead of a one-off. */ if (APR_BUCKET_IS_EOS(b)) { status = APR_EOF; break; } /* The reason I'm not offering brigade_consume yet * across to apr-util is that the following call * illustrates how borked that API really is. For * this sort of case (caller provided buffer) it * would be much more trivial for apr_bucket_consume * to do all the work that follows, based on the * particular characteristics of the bucket we are * consuming here. */ status = apr_bucket_read(b, &str, &str_len, block); if (status != APR_SUCCESS) { if (APR_STATUS_IS_EOF(status)) { /* This stream bucket was consumed */ apr_bucket_delete(b); continue; } break; } if (str_len > 0) { /* Do not block once some data has been consumed */ block = APR_NONBLOCK_READ; /* Assure we don't overflow. */ consume = (str_len + actual > *len) ? *len - actual : str_len; memcpy(c, str, consume); c += consume; actual += consume; if (consume >= b->length) { /* This physical bucket was consumed */ apr_bucket_delete(b); } else { /* Only part of this physical bucket was consumed */ b->start += consume; b->length -= consume; } } else if (b->length == 0) { apr_bucket_delete(b); } /* This could probably be actual == *len, but be safe from stray * photons. */ if (actual >= *len) { break; } } *len = actual; return status; } /* * this is the function called by SSL_read() */ static int bio_filter_in_read(BIO *bio, char *in, int inlen) { apr_size_t inl = inlen; bio_filter_in_ctx_t *inctx = (bio_filter_in_ctx_t *)(bio->ptr); apr_read_type_e block = inctx->block; SSLConnRec *sslconn = myConnConfig(inctx->f->c); inctx->rc = APR_SUCCESS; /* OpenSSL catches this case, so should we. */ if (!in) return 0; /* XXX: flush here only required for SSLv2; * OpenSSL calls BIO_flush() at the appropriate times for * the other protocols. */ if ((SSL_version(inctx->ssl) == SSL2_VERSION) || sslconn->is_proxy) { if (bio_filter_out_flush(inctx->bio_out) < 0) { bio_filter_out_ctx_t *outctx = (bio_filter_out_ctx_t *)(inctx->bio_out->ptr); inctx->rc = outctx->rc; return -1; } } BIO_clear_retry_flags(bio); if (!inctx->bb) { inctx->rc = APR_EOF; return -1; } if (APR_BRIGADE_EMPTY(inctx->bb)) { inctx->rc = ap_get_brigade(inctx->f->next, inctx->bb, AP_MODE_READBYTES, block, inl); /* If the read returns EAGAIN or success with an empty * brigade, return an error after setting the retry flag; * SSL_read() will then return -1, and SSL_get_error() will * indicate SSL_ERROR_WANT_READ. */ if (APR_STATUS_IS_EAGAIN(inctx->rc) || APR_STATUS_IS_EINTR(inctx->rc) || (inctx->rc == APR_SUCCESS && APR_BRIGADE_EMPTY(inctx->bb))) { BIO_set_retry_read(bio); return -1; } if (inctx->rc != APR_SUCCESS) { /* Unexpected errors discard the brigade */ apr_brigade_cleanup(inctx->bb); inctx->bb = NULL; return -1; } } inctx->rc = brigade_consume(inctx->bb, block, in, &inl); if (inctx->rc == APR_SUCCESS) { return (int)inl; } if (APR_STATUS_IS_EAGAIN(inctx->rc) || APR_STATUS_IS_EINTR(inctx->rc)) { BIO_set_retry_read(bio); return (int)inl; } /* Unexpected errors and APR_EOF clean out the brigade. * Subsequent calls will return APR_EOF. */ apr_brigade_cleanup(inctx->bb); inctx->bb = NULL; if (APR_STATUS_IS_EOF(inctx->rc) && inl) { /* Provide the results of this read pass, * without resetting the BIO retry_read flag */ return (int)inl; } return -1; } static BIO_METHOD bio_filter_in_method = { BIO_TYPE_MEM, "APR input filter", NULL, /* write is never called */ bio_filter_in_read, NULL, /* puts is never called */ NULL, /* gets is never called */ NULL, /* ctrl is never called */ bio_filter_create, bio_filter_destroy, #ifdef OPENSSL_VERSION_NUMBER NULL /* sslc does not have the callback_ctrl field */ #endif }; static apr_status_t ssl_io_input_read(bio_filter_in_ctx_t *inctx, char *buf, apr_size_t *len) { apr_size_t wanted = *len; apr_size_t bytes = 0; int rc; *len = 0; /* If we have something leftover from last time, try that first. */ if ((bytes = char_buffer_read(&inctx->cbuf, buf, wanted))) { *len = bytes; if (inctx->mode == AP_MODE_SPECULATIVE) { /* We want to rollback this read. */ if (inctx->cbuf.length > 0) { inctx->cbuf.value -= bytes; inctx->cbuf.length += bytes; } else { char_buffer_write(&inctx->cbuf, buf, (int)bytes); } return APR_SUCCESS; } /* This could probably be *len == wanted, but be safe from stray * photons. */ if (*len >= wanted) { return APR_SUCCESS; } if (inctx->mode == AP_MODE_GETLINE) { if (memchr(buf, APR_ASCII_LF, *len)) { return APR_SUCCESS; } } else { /* Down to a nonblock pattern as we have some data already */ inctx->block = APR_NONBLOCK_READ; } } while (1) { if (!inctx->filter_ctx->pssl) { /* Ensure a non-zero error code is returned */ if (inctx->rc == APR_SUCCESS) { inctx->rc = APR_EGENERAL; } break; } /* SSL_read may not read because we haven't taken enough data * from the stack. This is where we want to consider all of * the blocking and SPECULATIVE semantics */ rc = SSL_read(inctx->filter_ctx->pssl, buf + bytes, wanted - bytes); if (rc > 0) { *len += rc; if (inctx->mode == AP_MODE_SPECULATIVE) { /* We want to rollback this read. */ char_buffer_write(&inctx->cbuf, buf, rc); } return inctx->rc; } else if (rc == 0) { /* If EAGAIN, we will loop given a blocking read, * otherwise consider ourselves at EOF. */ if (APR_STATUS_IS_EAGAIN(inctx->rc) || APR_STATUS_IS_EINTR(inctx->rc)) { /* Already read something, return APR_SUCCESS instead. * On win32 in particular, but perhaps on other kernels, * a blocking call isn't 'always' blocking. */ if (*len > 0) { inctx->rc = APR_SUCCESS; break; } if (inctx->block == APR_NONBLOCK_READ) { break; } } else { if (*len > 0) { inctx->rc = APR_SUCCESS; } else { inctx->rc = APR_EOF; } break; } } else /* (rc < 0) */ { int ssl_err = SSL_get_error(inctx->filter_ctx->pssl, rc); conn_rec *c = (conn_rec*)SSL_get_app_data(inctx->filter_ctx->pssl); if (ssl_err == SSL_ERROR_WANT_READ) { /* * If OpenSSL wants to read more, and we were nonblocking, * report as an EAGAIN. Otherwise loop, pulling more * data from network filter. * * (This is usually the case when the client forces an SSL * renegotation which is handled implicitly by OpenSSL.) */ inctx->rc = APR_EAGAIN; if (*len > 0) { inctx->rc = APR_SUCCESS; break; } if (inctx->block == APR_NONBLOCK_READ) { break; } continue; /* Blocking and nothing yet? Try again. */ } else if (ssl_err == SSL_ERROR_SYSCALL) { if (APR_STATUS_IS_EAGAIN(inctx->rc) || APR_STATUS_IS_EINTR(inctx->rc)) { /* Already read something, return APR_SUCCESS instead. */ if (*len > 0) { inctx->rc = APR_SUCCESS; break; } if (inctx->block == APR_NONBLOCK_READ) { break; } continue; /* Blocking and nothing yet? Try again. */ } else { ap_log_cerror(APLOG_MARK, APLOG_INFO, inctx->rc, c, "SSL input filter read failed."); } } else /* if (ssl_err == SSL_ERROR_SSL) */ { /* * Log SSL errors and any unexpected conditions. */ ap_log_cerror(APLOG_MARK, APLOG_INFO, inctx->rc, c, "SSL library error %d reading data", ssl_err); ssl_log_ssl_error(APLOG_MARK, APLOG_INFO, c->base_server); } if (inctx->rc == APR_SUCCESS) { inctx->rc = APR_EGENERAL; } break; } } return inctx->rc; } static apr_status_t ssl_io_input_getline(bio_filter_in_ctx_t *inctx, char *buf, apr_size_t *len) { const char *pos = NULL; apr_status_t status; apr_size_t tmplen = *len, buflen = *len, offset = 0; *len = 0; /* * in most cases we get all the headers on the first SSL_read. * however, in certain cases SSL_read will only get a partial * chunk of the headers, so we try to read until LF is seen. */ while (tmplen > 0) { status = ssl_io_input_read(inctx, buf + offset, &tmplen); if (status != APR_SUCCESS) { return status; } *len += tmplen; if ((pos = memchr(buf, APR_ASCII_LF, *len))) { break; } offset += tmplen; tmplen = buflen - offset; } if (pos) { char *value; int length; apr_size_t bytes = pos - buf; bytes += 1; value = buf + bytes; length = *len - bytes; char_buffer_write(&inctx->cbuf, value, length); *len = bytes; } return APR_SUCCESS; } static apr_status_t ssl_filter_write(ap_filter_t *f, const char *data, apr_size_t len) { ssl_filter_ctx_t *filter_ctx = f->ctx; bio_filter_out_ctx_t *outctx; int res; /* write SSL */ if (filter_ctx->pssl == NULL) { return APR_EGENERAL; } outctx = (bio_filter_out_ctx_t *)filter_ctx->pbioWrite->ptr; res = SSL_write(filter_ctx->pssl, (unsigned char *)data, len); if (res < 0) { int ssl_err = SSL_get_error(filter_ctx->pssl, res); conn_rec *c = (conn_rec*)SSL_get_app_data(outctx->filter_ctx->pssl); if (ssl_err == SSL_ERROR_WANT_WRITE) { /* * If OpenSSL wants to write more, and we were nonblocking, * report as an EAGAIN. Otherwise loop, pushing more * data at the network filter. * * (This is usually the case when the client forces an SSL * renegotation which is handled implicitly by OpenSSL.) */ outctx->rc = APR_EAGAIN; } else if (ssl_err == SSL_ERROR_SYSCALL) { ap_log_cerror(APLOG_MARK, APLOG_INFO, outctx->rc, c, "SSL output filter write failed."); } else /* if (ssl_err == SSL_ERROR_SSL) */ { /* * Log SSL errors */ ap_log_cerror(APLOG_MARK, APLOG_INFO, outctx->rc, c, "SSL library error %d writing data", ssl_err); ssl_log_ssl_error(APLOG_MARK, APLOG_INFO, c->base_server); } if (outctx->rc == APR_SUCCESS) { outctx->rc = APR_EGENERAL; } } else if ((apr_size_t)res != len) { conn_rec *c = f->c; char *reason = "reason unknown"; /* XXX: probably a better way to determine this */ if (SSL_total_renegotiations(filter_ctx->pssl)) { reason = "likely due to failed renegotiation"; } ap_log_cerror(APLOG_MARK, APLOG_INFO, outctx->rc, c, "failed to write %" APR_SSIZE_T_FMT " of %" APR_SIZE_T_FMT " bytes (%s)", len - (apr_size_t)res, len, reason); outctx->rc = APR_EGENERAL; } return outctx->rc; } /* Just use a simple request. Any request will work for this, because * we use a flag in the conn_rec->conn_vector now. The fake request just * gets the request back to the Apache core so that a response can be sent. * * To avoid calling back for more data from the socket, use an HTTP/0.9 * request, and tack on an EOS bucket. */ #define HTTP_ON_HTTPS_PORT \ "GET /" CRLF #define HTTP_ON_HTTPS_PORT_BUCKET(alloc) \ apr_bucket_immortal_create(HTTP_ON_HTTPS_PORT, \ sizeof(HTTP_ON_HTTPS_PORT) - 1, \ alloc) static void ssl_io_filter_disable(SSLConnRec *sslconn, ap_filter_t *f) { bio_filter_in_ctx_t *inctx = f->ctx; SSL_free(inctx->ssl); sslconn->ssl = NULL; inctx->ssl = NULL; inctx->filter_ctx->pssl = NULL; } static apr_status_t ssl_io_filter_error(ap_filter_t *f, apr_bucket_brigade *bb, apr_status_t status) { SSLConnRec *sslconn = myConnConfig(f->c); apr_bucket *bucket; switch (status) { case HTTP_BAD_REQUEST: /* log the situation */ ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, f->c, "SSL handshake failed: HTTP spoken on HTTPS port; " "trying to send HTML error page"); ssl_log_ssl_error(APLOG_MARK, APLOG_INFO, f->c->base_server); sslconn->non_ssl_request = 1; ssl_io_filter_disable(sslconn, f); /* fake the request line */ bucket = HTTP_ON_HTTPS_PORT_BUCKET(f->c->bucket_alloc); break; default: return status; } APR_BRIGADE_INSERT_TAIL(bb, bucket); bucket = apr_bucket_eos_create(f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, bucket); return APR_SUCCESS; } static const char ssl_io_filter[] = "SSL/TLS Filter"; /* * Close the SSL part of the socket connection * (called immediately _before_ the socket is closed) * or called with */ static apr_status_t ssl_filter_io_shutdown(ssl_filter_ctx_t *filter_ctx, conn_rec *c, int abortive) { SSL *ssl = filter_ctx->pssl; const char *type = ""; SSLConnRec *sslconn = myConnConfig(c); int shutdown_type; if (!ssl) { return APR_SUCCESS; } /* * Now close the SSL layer of the connection. We've to take * the TLSv1 standard into account here: * * | 7.2.1. Closure alerts * | * | The client and the server must share knowledge that the connection is * | ending in order to avoid a truncation attack. Either party may * | initiate the exchange of closing messages. * | * | close_notify * | This message notifies the recipient that the sender will not send * | any more messages on this connection. The session becomes * | unresumable if any connection is terminated without proper * | close_notify messages with level equal to warning. * | * | Either party may initiate a close by sending a close_notify alert. * | Any data received after a closure alert is ignored. * | * | Each party is required to send a close_notify alert before closing * | the write side of the connection. It is required that the other party * | respond with a close_notify alert of its own and close down the * | connection immediately, discarding any pending writes. It is not * | required for the initiator of the close to wait for the responding * | close_notify alert before closing the read side of the connection. * * This means we've to send a close notify message, but haven't to wait * for the close notify of the client. Actually we cannot wait for the * close notify of the client because some clients (including Netscape * 4.x) don't send one, so we would hang. */ /* * exchange close notify messages, but allow the user * to force the type of handshake via SetEnvIf directive */ if (abortive) { shutdown_type = SSL_SENT_SHUTDOWN|SSL_RECEIVED_SHUTDOWN; type = "abortive"; } else switch (sslconn->shutdown_type) { case SSL_SHUTDOWN_TYPE_UNCLEAN: /* perform no close notify handshake at all (violates the SSL/TLS standard!) */ shutdown_type = SSL_SENT_SHUTDOWN|SSL_RECEIVED_SHUTDOWN; type = "unclean"; break; case SSL_SHUTDOWN_TYPE_ACCURATE: /* send close notify and wait for clients close notify (standard compliant, but usually causes connection hangs) */ shutdown_type = 0; type = "accurate"; break; default: /* * case SSL_SHUTDOWN_TYPE_UNSET: * case SSL_SHUTDOWN_TYPE_STANDARD: */ /* send close notify, but don't wait for clients close notify (standard compliant and safe, so it's the DEFAULT!) */ shutdown_type = SSL_RECEIVED_SHUTDOWN; type = "standard"; break; } SSL_set_shutdown(ssl, shutdown_type); SSL_smart_shutdown(ssl); /* and finally log the fact that we've closed the connection */ if (c->base_server->loglevel >= APLOG_INFO) { ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, c, "Connection closed to child %ld with %s shutdown " "(server %s)", c->id, type, ssl_util_vhostid(c->pool, c->base_server)); } /* deallocate the SSL connection */ if (sslconn->client_cert) { X509_free(sslconn->client_cert); sslconn->client_cert = NULL; } SSL_free(ssl); sslconn->ssl = NULL; filter_ctx->pssl = NULL; /* so filters know we've been shutdown */ if (abortive) { /* prevent any further I/O */ c->aborted = 1; } return APR_SUCCESS; } static apr_status_t ssl_io_filter_cleanup(void *data) { ssl_filter_ctx_t *filter_ctx = data; if (filter_ctx->pssl) { conn_rec *c = (conn_rec *)SSL_get_app_data(filter_ctx->pssl); SSLConnRec *sslconn = myConnConfig(c); SSL_free(filter_ctx->pssl); sslconn->ssl = filter_ctx->pssl = NULL; } return APR_SUCCESS; } /* * The hook is NOT registered with ap_hook_process_connection. Instead, it is * called manually from the churn () before it tries to read any data. * There is some problem if I accept conn_rec *. Still investigating.. * Adv. if conn_rec * can be accepted is we can hook this function using the * ap_hook_process_connection hook. */ static int ssl_io_filter_connect(ssl_filter_ctx_t *filter_ctx) { conn_rec *c = (conn_rec *)SSL_get_app_data(filter_ctx->pssl); SSLConnRec *sslconn = myConnConfig(c); SSLSrvConfigRec *sc = mySrvConfig(c->base_server); X509 *cert; int n; int ssl_err; long verify_result; if (SSL_is_init_finished(filter_ctx->pssl)) { return APR_SUCCESS; } if (sslconn->is_proxy) { if ((n = SSL_connect(filter_ctx->pssl)) <= 0) { ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, c, "SSL Proxy connect failed"); ssl_log_ssl_error(APLOG_MARK, APLOG_INFO, c->base_server); /* ensure that the SSL structures etc are freed, etc: */ ssl_filter_io_shutdown(filter_ctx, c, 1); return HTTP_BAD_GATEWAY; } return APR_SUCCESS; } if ((n = SSL_accept(filter_ctx->pssl)) <= 0) { bio_filter_in_ctx_t *inctx = (bio_filter_in_ctx_t *) (filter_ctx->pbioRead->ptr); bio_filter_out_ctx_t *outctx = (bio_filter_out_ctx_t *) (filter_ctx->pbioWrite->ptr); apr_status_t rc = inctx->rc ? inctx->rc : outctx->rc ; ssl_err = SSL_get_error(filter_ctx->pssl, n); if (ssl_err == SSL_ERROR_ZERO_RETURN) { /* * The case where the connection was closed before any data * was transferred. That's not a real error and can occur * sporadically with some clients. */ ap_log_cerror(APLOG_MARK, APLOG_INFO, rc, c, "SSL handshake stopped: connection was closed"); } else if (ssl_err == SSL_ERROR_WANT_READ) { /* * This is in addition to what was present earlier. It is * borrowed from openssl_state_machine.c [mod_tls]. * TBD. */ outctx->rc = APR_EAGAIN; return SSL_ERROR_WANT_READ; } else if (ERR_GET_LIB(ERR_peek_error()) == ERR_LIB_SSL && ERR_GET_REASON(ERR_peek_error()) == SSL_R_HTTP_REQUEST) { /* * The case where OpenSSL has recognized a HTTP request: * This means the client speaks plain HTTP on our HTTPS port. * ssl_io_filter_error will disable the ssl filters when it * sees this status code. */ return HTTP_BAD_REQUEST; } else if (ssl_err == SSL_ERROR_SYSCALL) { ap_log_cerror(APLOG_MARK, APLOG_INFO, rc, c, "SSL handshake interrupted by system " "[Hint: Stop button pressed in browser?!]"); } else /* if (ssl_err == SSL_ERROR_SSL) */ { /* * Log SSL errors and any unexpected conditions. */ ap_log_cerror(APLOG_MARK, APLOG_INFO, rc, c, "SSL library error %d in handshake " "(server %s)", ssl_err, ssl_util_vhostid(c->pool, c->base_server)); ssl_log_ssl_error(APLOG_MARK, APLOG_INFO, c->base_server); } if (inctx->rc == APR_SUCCESS) { inctx->rc = APR_EGENERAL; } return ssl_filter_io_shutdown(filter_ctx, c, 1); } /* * Check for failed client authentication */ verify_result = SSL_get_verify_result(filter_ctx->pssl); if ((verify_result != X509_V_OK) || sslconn->verify_error) { if (ssl_verify_error_is_optional(verify_result) && (sc->server->auth.verify_mode == SSL_CVERIFY_OPTIONAL_NO_CA)) { /* leaving this log message as an error for the moment, * according to the mod_ssl docs: * "level optional_no_ca is actually against the idea * of authentication (but can be used to establish * SSL test pages, etc.)" * optional_no_ca doesn't appear to work as advertised * in 1.x */ ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, c, "SSL client authentication failed, " "accepting certificate based on " "\"SSLVerifyClient optional_no_ca\" " "configuration"); ssl_log_ssl_error(APLOG_MARK, APLOG_INFO, c->base_server); } else { const char *error = sslconn->verify_error ? sslconn->verify_error : X509_verify_cert_error_string(verify_result); ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, c, "SSL client authentication failed: %s", error ? error : "unknown"); ssl_log_ssl_error(APLOG_MARK, APLOG_INFO, c->base_server); return ssl_filter_io_shutdown(filter_ctx, c, 1); } } /* * Remember the peer certificate's DN */ if ((cert = SSL_get_peer_certificate(filter_ctx->pssl))) { if (sslconn->client_cert) { X509_free(sslconn->client_cert); } sslconn->client_cert = cert; sslconn->client_dn = NULL; } /* * Make really sure that when a peer certificate * is required we really got one... (be paranoid) */ if ((sc->server->auth.verify_mode == SSL_CVERIFY_REQUIRE) && !sslconn->client_cert) { ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, c, "No acceptable peer certificate available"); return ssl_filter_io_shutdown(filter_ctx, c, 1); } return APR_SUCCESS; } #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" static apr_status_t ssl_io_filter_Upgrade(ap_filter_t *f, apr_bucket_brigade *bb) { const char *upgrade; apr_bucket_brigade *upgradebb; request_rec *r = f->r; SSLConnRec *sslconn; apr_status_t rv; apr_bucket *b; SSL *ssl; /* Just remove the filter, if it doesn't work the first time, it won't * work at all for this request. */ ap_remove_output_filter(f); /* No need to ensure that this is a server with optional SSL, the filter * is only inserted if that is true. */ upgrade = apr_table_get(r->headers_in, "Upgrade"); if (upgrade == NULL || strcmp(ap_getword(r->pool, &upgrade, ','), "TLS/1.0")) { /* "Upgrade: TLS/1.0, ..." header not found, don't do Upgrade */ return ap_pass_brigade(f->next, bb); } apr_table_unset(r->headers_out, "Upgrade"); /* Send the interim 101 response. */ upgradebb = apr_brigade_create(r->pool, f->c->bucket_alloc); ap_fputstrs(f->next, upgradebb, SWITCH_STATUS_LINE, CRLF, UPGRADE_HEADER, CRLF, CONNECTION_HEADER, CRLF, CRLF, NULL); b = apr_bucket_flush_create(f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(upgradebb, b); rv = ap_pass_brigade(f->next, upgradebb); if (rv) { ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, "could not send interim 101 Upgrade response"); return AP_FILTER_ERROR; } ssl_init_ssl_connection(f->c); ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, "Awaiting re-negotiation handshake"); sslconn = myConnConfig(f->c); ssl = sslconn->ssl; /* XXX: Should replace SSL_set_state with SSL_renegotiate(ssl); * However, this causes failures in perl-framework currently, * perhaps pre-test if we have already negotiated? */ 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, "TLS Upgrade handshake failed: " "Not accepted by client!?"); return AP_FILTER_ERROR; } /* Now that we have initialized the ssl connection which added the ssl_io_filter, pass the brigade off to the connection based output filters so that the request can complete encrypted */ return ap_pass_brigade(f->c->output_filters, bb); } static apr_status_t ssl_io_filter_input(ap_filter_t *f, apr_bucket_brigade *bb, ap_input_mode_t mode, apr_read_type_e block, apr_off_t readbytes) { apr_status_t status; bio_filter_in_ctx_t *inctx = f->ctx; apr_size_t len = sizeof(inctx->buffer); int is_init = (mode == AP_MODE_INIT); if (f->c->aborted) { /* XXX: Ok, if we aborted, we ARE at the EOS. We also have * aborted. This 'double protection' is probably redundant, * but also effective against just about anything. */ apr_bucket *bucket = apr_bucket_eos_create(f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, bucket); return APR_ECONNABORTED; } if (!inctx->ssl) { return ap_get_brigade(f->next, bb, mode, block, readbytes); } /* XXX: we don't currently support anything other than these modes. */ if (mode != AP_MODE_READBYTES && mode != AP_MODE_GETLINE && mode != AP_MODE_SPECULATIVE && mode != AP_MODE_INIT) { return APR_ENOTIMPL; } inctx->mode = mode; inctx->block = block; /* XXX: we could actually move ssl_io_filter_connect to an * ap_hook_process_connection but would still need to call it for * AP_MODE_INIT for protocols that may upgrade the connection * rather than have SSLEngine On configured. */ if ((status = ssl_io_filter_connect(inctx->filter_ctx)) != APR_SUCCESS) { return ssl_io_filter_error(f, bb, status); } if (is_init) { /* protocol module needs to handshake before sending * data to client (e.g. NNTP or FTP) */ return APR_SUCCESS; } if (inctx->mode == AP_MODE_READBYTES || inctx->mode == AP_MODE_SPECULATIVE) { /* Protected from truncation, readbytes < MAX_SIZE_T * FIXME: No, it's *not* protected. -- jre */ if (readbytes < len) { len = (apr_size_t)readbytes; } status = ssl_io_input_read(inctx, inctx->buffer, &len); } else if (inctx->mode == AP_MODE_GETLINE) { status = ssl_io_input_getline(inctx, inctx->buffer, &len); } else { /* We have no idea what you are talking about, so return an error. */ return APR_ENOTIMPL; } if (status != APR_SUCCESS) { return ssl_io_filter_error(f, bb, status); } /* Create a transient bucket out of the decrypted data. */ if (len > 0) { apr_bucket *bucket = apr_bucket_transient_create(inctx->buffer, len, f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(bb, bucket); } return APR_SUCCESS; } static apr_status_t ssl_io_filter_output(ap_filter_t *f, apr_bucket_brigade *bb) { apr_status_t status = APR_SUCCESS; ssl_filter_ctx_t *filter_ctx = f->ctx; bio_filter_in_ctx_t *inctx; bio_filter_out_ctx_t *outctx; apr_read_type_e rblock = APR_NONBLOCK_READ; if (f->c->aborted) { apr_brigade_cleanup(bb); return APR_ECONNABORTED; } if (!filter_ctx->pssl) { /* ssl_filter_io_shutdown was called */ return ap_pass_brigade(f->next, bb); } inctx = (bio_filter_in_ctx_t *)filter_ctx->pbioRead->ptr; outctx = (bio_filter_out_ctx_t *)filter_ctx->pbioWrite->ptr; /* When we are the writer, we must initialize the inctx * mode so that we block for any required ssl input, because * output filtering is always nonblocking. */ inctx->mode = AP_MODE_READBYTES; inctx->block = APR_BLOCK_READ; if ((status = ssl_io_filter_connect(filter_ctx)) != APR_SUCCESS) { return ssl_io_filter_error(f, bb, status); } while (!APR_BRIGADE_EMPTY(bb)) { apr_bucket *bucket = APR_BRIGADE_FIRST(bb); /* If it is a flush or EOS, we need to pass this down. * These types do not require translation by OpenSSL. */ if (APR_BUCKET_IS_EOS(bucket) || APR_BUCKET_IS_FLUSH(bucket)) { if (bio_filter_out_flush(filter_ctx->pbioWrite) < 0) { status = outctx->rc; break; } if (APR_BUCKET_IS_EOS(bucket)) { /* * By definition, nothing can come after EOS. * which also means we can pass the rest of this brigade * without creating a new one since it only contains the * EOS bucket. */ if ((status = ap_pass_brigade(f->next, bb)) != APR_SUCCESS) { return status; } break; } else { /* bio_filter_out_flush() already passed down a flush bucket * if there was any data to be flushed. */ apr_bucket_delete(bucket); } } else if (AP_BUCKET_IS_EOC(bucket)) { /* The special "EOC" bucket means a shutdown is needed; * - turn off buffering in bio_filter_out_write * - issue the SSL_shutdown */ filter_ctx->nobuffer = 1; status = ssl_filter_io_shutdown(filter_ctx, f->c, 0); if (status != APR_SUCCESS) { ap_log_cerror(APLOG_MARK, APLOG_INFO, status, f->c, "SSL filter error shutting down I/O"); } if ((status = ap_pass_brigade(f->next, bb)) != APR_SUCCESS) { return status; } break; } else { /* filter output */ const char *data; apr_size_t len; status = apr_bucket_read(bucket, &data, &len, rblock); if (APR_STATUS_IS_EAGAIN(status)) { /* No data available: flush... */ if (bio_filter_out_flush(filter_ctx->pbioWrite) < 0) { status = outctx->rc; break; } rblock = APR_BLOCK_READ; continue; /* and try again with a blocking read. */ } rblock = APR_NONBLOCK_READ; if (!APR_STATUS_IS_EOF(status) && (status != APR_SUCCESS)) { break; } status = ssl_filter_write(f, data, len); apr_bucket_delete(bucket); if (status != APR_SUCCESS) { break; } } } return status; } static void ssl_io_input_add_filter(ssl_filter_ctx_t *filter_ctx, conn_rec *c, SSL *ssl) { bio_filter_in_ctx_t *inctx; inctx = apr_palloc(c->pool, sizeof(*inctx)); filter_ctx->pInputFilter = ap_add_input_filter(ssl_io_filter, inctx, NULL, c); filter_ctx->pbioRead = BIO_new(&bio_filter_in_method); filter_ctx->pbioRead->ptr = (void *)inctx; inctx->ssl = ssl; inctx->bio_out = filter_ctx->pbioWrite; inctx->f = filter_ctx->pInputFilter; inctx->rc = APR_SUCCESS; inctx->mode = AP_MODE_READBYTES; inctx->cbuf.length = 0; inctx->bb = apr_brigade_create(c->pool, c->bucket_alloc); inctx->block = APR_BLOCK_READ; inctx->pool = c->pool; inctx->filter_ctx = filter_ctx; } void ssl_io_filter_init(conn_rec *c, SSL *ssl) { ssl_filter_ctx_t *filter_ctx; filter_ctx = apr_palloc(c->pool, sizeof(ssl_filter_ctx_t)); filter_ctx->pOutputFilter = ap_add_output_filter(ssl_io_filter, filter_ctx, NULL, c); filter_ctx->pbioWrite = BIO_new(&bio_filter_out_method); filter_ctx->pbioWrite->ptr = (void *)bio_filter_out_ctx_new(filter_ctx, c); ssl_io_input_add_filter(filter_ctx, c, ssl); SSL_set_bio(ssl, filter_ctx->pbioRead, filter_ctx->pbioWrite); filter_ctx->pssl = ssl; apr_pool_cleanup_register(c->pool, (void*)filter_ctx, ssl_io_filter_cleanup, apr_pool_cleanup_null); if (c->base_server->loglevel >= APLOG_DEBUG) { BIO_set_callback(SSL_get_rbio(ssl), ssl_io_data_cb); BIO_set_callback_arg(SSL_get_rbio(ssl), (void *)ssl); } return; } void ssl_io_filter_register(apr_pool_t *p) { /* This filter MUST be after the HTTP_HEADER filter, but it also must be * a resource-level filter so it has the request_rec. */ ap_register_output_filter ("UPGRADE_FILTER", ssl_io_filter_Upgrade, NULL, AP_FTYPE_PROTOCOL + 5); 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); return; } /* _________________________________________________________________ ** ** I/O Data Debugging ** _________________________________________________________________ */ #define DUMP_WIDTH 16 static void ssl_io_data_dump(server_rec *srvr, MODSSL_BIO_CB_ARG_TYPE *s, long len) { char buf[256]; char tmp[64]; int i, j, rows, trunc; unsigned char ch; trunc = 0; for(; (len > 0) && ((s[len-1] == ' ') || (s[len-1] == '\0')); len--) trunc++; rows = (len / DUMP_WIDTH); if ((rows * DUMP_WIDTH) < len) rows++; ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, srvr, "+-------------------------------------------------------------------------+"); for(i = 0 ; i< rows; i++) { apr_snprintf(tmp, sizeof(tmp), "| %04x: ", i * DUMP_WIDTH); apr_cpystrn(buf, tmp, sizeof(buf)); for (j = 0; j < DUMP_WIDTH; j++) { if (((i * DUMP_WIDTH) + j) >= len) apr_cpystrn(buf+strlen(buf), " ", sizeof(buf)-strlen(buf)); else { ch = ((unsigned char)*((char *)(s) + i * DUMP_WIDTH + j)) & 0xff; apr_snprintf(tmp, sizeof(tmp), "%02x%c", ch , j==7 ? '-' : ' '); apr_cpystrn(buf+strlen(buf), tmp, sizeof(buf)-strlen(buf)); } } apr_cpystrn(buf+strlen(buf), " ", sizeof(buf)-strlen(buf)); for (j = 0; j < DUMP_WIDTH; j++) { if (((i * DUMP_WIDTH) + j) >= len) apr_cpystrn(buf+strlen(buf), " ", sizeof(buf)-strlen(buf)); else { ch = ((unsigned char)*((char *)(s) + i * DUMP_WIDTH + j)) & 0xff; apr_snprintf(tmp, sizeof(tmp), "%c", ((ch >= ' ') && (ch <= '~')) ? ch : '.'); apr_cpystrn(buf+strlen(buf), tmp, sizeof(buf)-strlen(buf)); } } apr_cpystrn(buf+strlen(buf), " |", sizeof(buf)-strlen(buf)); ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, srvr, "%s", buf); } if (trunc > 0) ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, srvr, "| %04ld - ", len + trunc); ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, srvr, "+-------------------------------------------------------------------------+"); return; } long ssl_io_data_cb(BIO *bio, int cmd, MODSSL_BIO_CB_ARG_TYPE *argp, int argi, long argl, long rc) { SSL *ssl; conn_rec *c; server_rec *s; if ((ssl = (SSL *)BIO_get_callback_arg(bio)) == NULL) return rc; if ((c = (conn_rec *)SSL_get_app_data(ssl)) == NULL) return rc; s = c->base_server; if ( cmd == (BIO_CB_WRITE|BIO_CB_RETURN) || cmd == (BIO_CB_READ |BIO_CB_RETURN) ) { if (rc >= 0) { ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, "%s: %s %ld/%d bytes %s BIO#%pp [mem: %pp] %s", SSL_LIBRARY_NAME, (cmd == (BIO_CB_WRITE|BIO_CB_RETURN) ? "write" : "read"), rc, argi, (cmd == (BIO_CB_WRITE|BIO_CB_RETURN) ? "to" : "from"), bio, argp, (argp != NULL ? "(BIO dump follows)" : "(Oops, no memory buffer?)")); if (argp != NULL) ssl_io_data_dump(s, argp, rc); } else { ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, "%s: I/O error, %d bytes expected to %s on BIO#%pp [mem: %pp]", SSL_LIBRARY_NAME, argi, (cmd == (BIO_CB_WRITE|BIO_CB_RETURN) ? "write" : "read"), bio, argp); } } return rc; }