aboutsummaryrefslogtreecommitdiffstats
path: root/src/mod_gnutls.c
blob: bf0d9c3590165636cf957c1dc6ca276184ea6f9c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
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
};