1 files changed, 465 insertions, 0 deletions

diff --git a/src/mod_gnutls.c b/src/mod_gnutls.c
new file mode 100644
index 0000000..bf0d9c3
--- /dev/null
+++ b/src/mod_gnutls.c
@@ -0,0 +1,465 @@
+/* ====================================================================
+ *  Copyright 2004 Paul Querna
+ *
+ *  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.
+ *
+ */
+
+#include "httpd.h"
+#include "http_config.h"
+#include "http_protocol.h"
+#include "http_connection.h"
+#include "http_core.h"
+#include "http_log.h"
+#include "apr_buckets.h"
+#include "apr_strings.h"
+#include "apr_tables.h"
+
+#include <gcrypt.h>
+#include <gnutls/gnutls.h>
+
+#if APR_HAS_THREADS
+GCRY_THREAD_OPTION_PTHREAD_IMPL;
+#endif
+
+module AP_MODULE_DECLARE_DATA gnutls_module;
+
+#define GNUTLS_OUTPUT_FILTER_NAME "GnuTLS Output Filter"
+#define GNUTLS_INPUT_FILTER_NAME "GnuTLS Input Filter"
+
+#define GNUTLS_ENABLED_FALSE 0
+#define GNUTLS_ENABLED_TRUE  1
+
+
+typedef struct gnutls_srvconf_t gnutls_srvconf_t;
+struct gnutls_srvconf_t
+{
+    gnutls_certificate_credentials_t certs;
+    char *key_file;
+    char *cert_file;
+    int enabled;
+};
+
+typedef struct gnutls_handle_t gnutls_handle_t;
+struct gnutls_handle_t
+{
+    gnutls_srvconf_t *sc;
+    gnutls_session_t session;
+    ap_filter_t *input_filter;
+    apr_bucket_brigade *input_bb;
+    apr_read_type_e input_block;
+};
+
+static apr_status_t gnutls_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 = APR_SUCCESS;
+    gnutls_handle_t *ctxt = (gnutls_handle_t *) f->ctx;
+
+    if (f->c->aborted) {
+        apr_bucket *bucket = apr_bucket_eos_create(f->c->bucket_alloc);
+        APR_BRIGADE_INSERT_TAIL(bb, bucket);
+        return APR_ECONNABORTED;
+    }
+
+    return status;
+}
+
+static apr_status_t gnutls_filter_output(ap_filter_t * f,
+                                         apr_bucket_brigade * bb)
+{
+    apr_bucket *b;
+    const char *buf = 0;
+    apr_size_t bytes = 0;
+    gnutls_handle_t *ctxt = (gnutls_handle_t *) f->ctx;
+    apr_status_t status = APR_SUCCESS;
+
+    if (!ctxt) {
+        /* first run. */
+    }
+
+    for (b = APR_BRIGADE_FIRST(bb);
+         b != APR_BRIGADE_SENTINEL(bb); b = APR_BUCKET_NEXT(b)) {
+        if (APR_BUCKET_IS_EOS(b)) {
+            /* end of connection */
+        }
+        else if (apr_bucket_read(b, &buf, &bytes, APR_BLOCK_READ)
+                 == APR_SUCCESS) {
+            /* more data */
+        }
+    }
+
+    return status;
+}
+
+static apr_status_t gnutls_cleanup_pre_config(void *data)
+{
+    gnutls_global_deinit();
+    return APR_SUCCESS;
+}
+
+static int gnutls_hook_pre_config(apr_pool_t * pconf,
+                                  apr_pool_t * plog, apr_pool_t * ptemp)
+{
+
+#if APR_HAS_THREADS
+    gcry_control(GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
+#endif
+
+    gnutls_global_init();
+
+    apr_pool_cleanup_register(pconf, NULL, gnutls_cleanup_pre_config,
+                              apr_pool_cleanup_null);
+
+    return OK;
+}
+
+#define DH_BITS 1024
+#define RSA_BITS 512
+
+static int gnutls_hook_post_config(apr_pool_t * p, apr_pool_t * plog,
+                                   apr_pool_t * ptemp,
+                                   server_rec * base_server)
+{
+    gnutls_srvconf_t *sc;
+    server_rec *s;
+    gnutls_dh_params_t dh_params;
+    gnutls_rsa_params_t rsa_params;
+
+
+    /* TODO: Should we regenerate these after X requests / X time ? */
+    gnutls_dh_params_init(&dh_params);
+    gnutls_dh_params_generate2(dh_params, DH_BITS);
+    gnutls_rsa_params_init(&rsa_params);
+    gnutls_rsa_params_generate2(rsa_params, RSA_BITS);
+
+    for (s = base_server; s; s = s->next) {
+        sc = (gnutls_srvconf_t *) ap_get_module_config(s->module_config,
+                                                       &gnutls_module);
+        if (sc->cert_file != NULL && sc->key_file != NULL) {
+            gnutls_certificate_set_x509_key_file(sc->certs, sc->cert_file,
+                                                 sc->key_file,
+                                                 GNUTLS_X509_FMT_PEM);
+        }
+        else {
+            ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s,
+                         "[GnuTLS] - Host '%s' is missing a Cert and Key File!",
+                         s->server_hostname);
+        }
+
+        /**
+         * TODO: Is it okay for all virtual hosts to 
+         *       share the same DH/RSAparams? 
+         */
+        gnutls_certificate_set_dh_params(sc->certs, dh_params);
+        gnutls_certificate_set_rsa_export_params(sc->certs, rsa_params);
+    }
+
+    ap_add_version_component(p, "GnuTLS/" LIBGNUTLS_VERSION);
+    return OK;
+}
+
+static const char *gnutls_hook_http_method(const request_rec * r)
+{
+    gnutls_srvconf_t *sc =
+        (gnutls_srvconf_t *) ap_get_module_config(r->server->module_config,
+                                                  &gnutls_module);
+
+    if (sc->enabled == GNUTLS_ENABLED_FALSE) {
+        return NULL;
+    }
+
+    return "https";
+}
+
+static apr_port_t gnutls_hook_default_port(const request_rec * r)
+{
+    gnutls_srvconf_t *sc =
+        (gnutls_srvconf_t *) ap_get_module_config(r->server->module_config,
+                                                  &gnutls_module);
+
+    if (sc->enabled == GNUTLS_ENABLED_FALSE) {
+        return 0;
+    }
+
+    return 443;
+}
+
+/**
+ * From mod_ssl / ssl_engine_io.c
+ * 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;
+}
+
+
+static ssize_t gnutls_transport_read(gnutls_transport_ptr_t ptr,
+                                     void *buffer, size_t len)
+{
+    gnutls_handle_t *ctxt = ptr;
+    apr_status_t rc;
+    apr_size_t in = len;
+    /* If Len = 0, we don't do anything. */
+    if (!len)
+        return 0;
+
+    if (APR_BRIGADE_EMPTY(ctxt->input_bb)) {
+
+        rc = ap_get_brigade(ctxt->input_filter->next, ctxt->input_bb,
+                            AP_MODE_READBYTES, ctxt->input_block, in);
+
+        /* Not a problem, there was simply no data ready yet.
+         */
+        if (APR_STATUS_IS_EAGAIN(rc) || APR_STATUS_IS_EINTR(rc)
+            || (rc == APR_SUCCESS && APR_BRIGADE_EMPTY(ctxt->input_bb))) {
+            return 0;
+        }
+
+        if (rc != APR_SUCCESS) {
+            /* Unexpected errors discard the brigade */
+            apr_brigade_cleanup(ctxt->input_bb);
+            ctxt->input_bb = NULL;
+            return -1;
+        }
+    }
+
+//    brigade_consume(ctxt->input_bb, ctxt->input_block, buffer, &len);
+
+
+    ap_get_brigade(ctxt->input_filter->next, ctxt->input_bb,
+                   AP_MODE_READBYTES, ctxt->input_block, len);
+
+    return len;
+}
+
+static ssize_t gnutls_transport_write(gnutls_transport_ptr_t ptr,
+                                      const void *buffer, size_t len)
+{
+    gnutls_handle_t *ctxt = ptr;
+
+//    apr_bucket *bucket = apr_bucket_transient_create(in, inl,
+//                                                     outctx->bb->
+//                                                     bucket_alloc);
+
+    //  outctx->length += inl;
+    //APR_BRIGADE_INSERT_TAIL(outctx->bb, bucket);
+    return 0;
+}
+
+static int gnutls_hook_pre_connection(conn_rec * c, void *csd)
+{
+#ifndef GNUTLS_AS_FILTER
+    int cfd;
+#endif
+    gnutls_handle_t *ctxt;
+    gnutls_srvconf_t *sc =
+        (gnutls_srvconf_t *) ap_get_module_config(c->base_server->
+                                                  module_config,
+                                                  &gnutls_module);
+
+    if (!(sc && (sc->enabled == GNUTLS_ENABLED_TRUE))) {
+        return DECLINED;
+    }
+
+    ctxt = apr_pcalloc(c->pool, sizeof(*ctxt));
+
+    ctxt->sc = sc;
+    gnutls_init(&ctxt->session, GNUTLS_SERVER);
+
+    gnutls_set_default_priority(ctxt->session);
+
+    gnutls_credentials_set(ctxt->session, GNUTLS_CRD_CERTIFICATE, sc->certs);
+
+    gnutls_certificate_server_set_request(ctxt->session, GNUTLS_CERT_REQUEST);
+
+    gnutls_dh_set_prime_bits(ctxt->session, DH_BITS);
+
+    ap_set_module_config(c->conn_config, &gnutls_module, ctxt);
+
+#ifdef GNUTLS_AS_FILTER
+    gnutls_transport_set_pull_function(ctxt->session, gnutls_transport_read);
+    gnutls_transport_set_push_function(ctxt->session, gnutls_transport_write);
+    gnutls_transport_set_ptr(ctxt->session, ctxt);
+
+    ap_add_input_filter(GNUTLS_INPUT_FILTER_NAME, ctxt, NULL, c);
+    ap_add_output_filter(GNUTLS_OUTPUT_FILTER_NAME, ctxt, NULL, c);
+#else
+    apr_os_sock_get(&cfd, csd);
+    gnutls_transport_set_ptr(ctxt->session, (gnutls_transport_ptr)cfd);
+#endif
+    return OK;
+}
+
+static const char *gnutls_set_ca_file(cmd_parms * parms, void *dummy,
+                                      const char *arg)
+{
+    gnutls_srvconf_t *sc =
+        (gnutls_srvconf_t *) ap_get_module_config(parms->server->
+                                                  module_config,
+                                                  &gnutls_module);
+/* TODO: CRL, CAFile */
+//    gnutls_certificate_set_x509_trust_file(sc->certs, CAFILE,
+//                                         GNUTLS_X509_FMT_PEM);
+    return NULL;
+}
+
+static const command_rec gnutls_cmds[] = {
+    AP_INIT_FLAG("GnuTLSEnable", ap_set_flag_slot,
+                 (void *) APR_OFFSETOF(gnutls_srvconf_t, enabled), RSRC_CONF,
+                 "Whether this server has GnuTLS Enabled. Default: Off"),
+    AP_INIT_TAKE1("GnuTLSCertificateFile", ap_set_string_slot,
+                  (void *) APR_OFFSETOF(gnutls_srvconf_t, cert_file),
+                  RSRC_CONF,
+                  "SSL Server Key file"),
+    AP_INIT_TAKE1("GnuTLSKeyFile", ap_set_string_slot,
+                  (void *) APR_OFFSETOF(gnutls_srvconf_t, key_file),
+                  RSRC_CONF,
+                  "SSL Server Certificate file"),
+    {NULL}
+};
+
+/* TODO: CACertificateFile & Client Authentication
+ *    AP_INIT_TAKE1("GnuTLSCACertificateFile", ap_set_server_string_slot,
+ *                 (void *) APR_OFFSETOF(gnutls_srvconf_t, key_file), NULL,
+ *                 RSRC_CONF,
+ *                 "CA"),
+ */
+
+static void gnutls_hooks(apr_pool_t * p)
+{
+    ap_hook_pre_connection(gnutls_hook_pre_connection, NULL, NULL,
+                           APR_HOOK_MIDDLE);
+    ap_hook_post_config(gnutls_hook_post_config, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_http_method(gnutls_hook_http_method, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_default_port(gnutls_hook_default_port, NULL, NULL,
+                         APR_HOOK_MIDDLE);
+    ap_hook_pre_config(gnutls_hook_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
+
+    /* TODO: HTTP Upgrade Filter */
+    /* ap_register_output_filter ("UPGRADE_FILTER", 
+     *          ssl_io_filter_Upgrade, NULL, AP_FTYPE_PROTOCOL + 5);
+     */
+
+    ap_register_input_filter(GNUTLS_INPUT_FILTER_NAME, gnutls_filter_input,
+                             NULL, AP_FTYPE_CONNECTION + 5);
+    ap_register_output_filter(GNUTLS_OUTPUT_FILTER_NAME, gnutls_filter_output,
+                              NULL, AP_FTYPE_CONNECTION + 5);
+
+}
+
+static void *gnutls_config_server_create(apr_pool_t * p, server_rec * s)
+{
+    gnutls_srvconf_t *sc = apr_pcalloc(p, sizeof *sc);
+
+    sc->enabled = GNUTLS_ENABLED_FALSE;
+
+    gnutls_certificate_allocate_credentials(&sc->certs);
+
+    sc->key_file = NULL;
+    sc->cert_file = NULL;
+    return sc;
+}
+
+
+
+module AP_MODULE_DECLARE_DATA gnutls_module = {
+    STANDARD20_MODULE_STUFF,
+    NULL,
+    NULL,
+    gnutls_config_server_create,
+    NULL,
+/*    gnutls_config_server_merge, */
+    gnutls_cmds,
+    gnutls_hooks
+};