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construct/libratbox/src/mbedtls.c
Elizabeth Myers e6bbb41030 Add ability to change CertFP hash.
Presently this only supports SHA1, as the machinery to actually change
the cipher is not hooked up to anything yet.
2015-12-07 01:14:02 -06:00

599 lines
13 KiB
C

/*
* libratbox: a library used by ircd-ratbox and other things
* mbedtls.c: mbedtls related code
*
* Copyright (C) 2007-2008 ircd-ratbox development team
* Copyright (C) 2007-2008 Aaron Sethman <androsyn@ratbox.org>
* Copyright (C) 2015 William Pitcock <nenolod@dereferenced.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
* USA
*
* $Id$
*/
#include <libratbox_config.h>
#include <ratbox_lib.h>
#include <commio-int.h>
#include <commio-ssl.h>
#ifdef HAVE_MBEDTLS
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/certs.h"
#include "mbedtls/x509.h"
#include "mbedtls/ssl.h"
#include "mbedtls/net.h"
#include "mbedtls/error.h"
#include "mbedtls/debug.h"
#include "mbedtls/dhm.h"
#include "mbedtls/version.h"
static mbedtls_x509_crt x509;
static mbedtls_pk_context serv_pk;
static mbedtls_dhm_context dh_params;
static mbedtls_ctr_drbg_context ctr_drbg;
static mbedtls_entropy_context entropy;
static mbedtls_ssl_config serv_config;
static mbedtls_ssl_config client_config;
#define SSL_P(x) ((mbedtls_ssl_context *)F->ssl)
void
rb_ssl_shutdown(rb_fde_t *F)
{
int i;
if(F == NULL || F->ssl == NULL)
return;
for(i = 0; i < 4; i++)
{
int r = mbedtls_ssl_close_notify(SSL_P(F));
if(r != MBEDTLS_ERR_SSL_WANT_READ && r != MBEDTLS_ERR_SSL_WANT_WRITE)
break;
}
mbedtls_ssl_free(SSL_P(F));
rb_free(F->ssl);
}
unsigned int
rb_ssl_handshake_count(rb_fde_t *F)
{
return F->handshake_count;
}
void
rb_ssl_clear_handshake_count(rb_fde_t *F)
{
F->handshake_count = 0;
}
static void
rb_ssl_timeout(rb_fde_t *F, void *notused)
{
lrb_assert(F->accept != NULL);
F->accept->callback(F, RB_ERR_TIMEOUT, NULL, 0, F->accept->data);
}
static int
do_ssl_handshake(rb_fde_t *F, PF * callback, void *data)
{
int ret;
int flags;
ret = mbedtls_ssl_handshake(SSL_P(F));
if(ret < 0)
{
if (ret == -1 && rb_ignore_errno(errno))
ret = MBEDTLS_ERR_SSL_WANT_READ;
if((ret == MBEDTLS_ERR_SSL_WANT_READ || ret == MBEDTLS_ERR_SSL_WANT_WRITE))
{
if(ret == MBEDTLS_ERR_SSL_WANT_READ)
flags = RB_SELECT_READ;
else
flags = RB_SELECT_WRITE;
rb_setselect(F, flags, callback, data);
return 0;
}
F->ssl_errno = ret;
return -1;
}
return 1; /* handshake is finished..go about life */
}
static void
rb_ssl_tryaccept(rb_fde_t *F, void *data)
{
int ret;
struct acceptdata *ad;
lrb_assert(F->accept != NULL);
ret = do_ssl_handshake(F, rb_ssl_tryaccept, NULL);
/* do_ssl_handshake does the rb_setselect */
if(ret == 0)
return;
ad = F->accept;
F->accept = NULL;
rb_settimeout(F, 0, NULL, NULL);
rb_setselect(F, RB_SELECT_READ | RB_SELECT_WRITE, NULL, NULL);
if(ret > 0)
ad->callback(F, RB_OK, (struct sockaddr *)&ad->S, ad->addrlen, ad->data);
else
ad->callback(F, RB_ERROR_SSL, NULL, 0, ad->data);
rb_free(ad);
}
static int
rb_ssl_read_cb(void *opaque, unsigned char *buf, size_t size)
{
int ret;
rb_fde_t *F = opaque;
ret = read(F->fd, buf, size);
if (ret < 0 && rb_ignore_errno(errno))
return MBEDTLS_ERR_SSL_WANT_READ;
return ret;
}
static int
rb_ssl_write_cb(void *opaque, const unsigned char *buf, size_t size)
{
rb_fde_t *F = opaque;
int ret;
ret = write(F->fd, buf, size);
if (ret < 0 && rb_ignore_errno(errno))
return MBEDTLS_ERR_SSL_WANT_WRITE;
return ret;
}
static void
rb_ssl_setup_srv_context(rb_fde_t *F, mbedtls_ssl_context *ssl)
{
int ret;
mbedtls_ssl_init(ssl);
if ((ret = mbedtls_ssl_setup(ssl, &serv_config)) != 0)
{
rb_lib_log("rb_ssl_setup_srv_context: failed to set up ssl context: -0x%x", -ret);
rb_close(F);
return;
}
mbedtls_ssl_set_bio(ssl, F, rb_ssl_write_cb, rb_ssl_read_cb, NULL);
}
void
rb_ssl_start_accepted(rb_fde_t *new_F, ACCB * cb, void *data, int timeout)
{
mbedtls_ssl_context *ssl;
new_F->type |= RB_FD_SSL;
ssl = new_F->ssl = rb_malloc(sizeof(mbedtls_ssl_context));
new_F->accept = rb_malloc(sizeof(struct acceptdata));
new_F->accept->callback = cb;
new_F->accept->data = data;
rb_settimeout(new_F, timeout, rb_ssl_timeout, NULL);
new_F->accept->addrlen = 0;
rb_ssl_setup_srv_context(new_F, ssl);
if(do_ssl_handshake(new_F, rb_ssl_tryaccept, NULL))
{
struct acceptdata *ad = new_F->accept;
new_F->accept = NULL;
ad->callback(new_F, RB_OK, (struct sockaddr *)&ad->S, ad->addrlen, ad->data);
rb_free(ad);
}
}
void
rb_ssl_accept_setup(rb_fde_t *F, rb_fde_t *new_F, struct sockaddr *st, int addrlen)
{
new_F->type |= RB_FD_SSL;
new_F->ssl = rb_malloc(sizeof(mbedtls_ssl_context));
new_F->accept = rb_malloc(sizeof(struct acceptdata));
new_F->accept->callback = F->accept->callback;
new_F->accept->data = F->accept->data;
rb_settimeout(new_F, 10, rb_ssl_timeout, NULL);
memcpy(&new_F->accept->S, st, addrlen);
new_F->accept->addrlen = addrlen;
rb_ssl_setup_srv_context(new_F, new_F->ssl);
if(do_ssl_handshake(F, rb_ssl_tryaccept, NULL))
{
struct acceptdata *ad = F->accept;
F->accept = NULL;
ad->callback(F, RB_OK, (struct sockaddr *)&ad->S, ad->addrlen, ad->data);
rb_free(ad);
}
}
static ssize_t
rb_ssl_read_or_write(int r_or_w, rb_fde_t *F, void *rbuf, const void *wbuf, size_t count)
{
ssize_t ret;
if(r_or_w == 0)
ret = mbedtls_ssl_read(F->ssl, rbuf, count);
else
ret = mbedtls_ssl_write(F->ssl, wbuf, count);
if(ret < 0)
{
switch (ret)
{
case MBEDTLS_ERR_SSL_WANT_READ:
return RB_RW_SSL_NEED_READ;
case MBEDTLS_ERR_SSL_WANT_WRITE:
return RB_RW_SSL_NEED_WRITE;
default:
F->ssl_errno = ret;
errno = EIO;
return RB_RW_IO_ERROR;
}
}
return ret;
}
ssize_t
rb_ssl_read(rb_fde_t *F, void *buf, size_t count)
{
return rb_ssl_read_or_write(0, F, buf, NULL, count);
}
ssize_t
rb_ssl_write(rb_fde_t *F, const void *buf, size_t count)
{
return rb_ssl_read_or_write(1, F, NULL, buf, count);
}
int
rb_init_ssl(void)
{
int ret;
mbedtls_entropy_init(&entropy);
mbedtls_ctr_drbg_init(&ctr_drbg);
if((ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy, NULL, 0)) != 0)
{
rb_lib_log("rb_init_prng: unable to initialize PRNG, mbedtls_ctr_drbg_seed() returned -0x%x", -ret);
return 0;
}
mbedtls_ssl_config_init(&serv_config);
if ((ret = mbedtls_ssl_config_defaults(&serv_config,
MBEDTLS_SSL_IS_SERVER,
MBEDTLS_SSL_TRANSPORT_STREAM,
MBEDTLS_SSL_PRESET_DEFAULT)) != 0)
{
rb_lib_log("rb_init_ssl: unable to initialize default SSL parameters for server context: -0x%x", -ret);
return 0;
}
mbedtls_ssl_conf_rng(&serv_config, mbedtls_ctr_drbg_random, &ctr_drbg);
/***************************************************************************************************************/
mbedtls_ssl_config_init(&client_config);
if ((ret = mbedtls_ssl_config_defaults(&client_config,
MBEDTLS_SSL_IS_CLIENT,
MBEDTLS_SSL_TRANSPORT_STREAM,
MBEDTLS_SSL_PRESET_DEFAULT)) != 0)
{
rb_lib_log("rb_init_ssl: unable to initialize default SSL parameters for client context: -0x%x", -ret);
return 0;
}
mbedtls_ssl_conf_rng(&client_config, mbedtls_ctr_drbg_random, &ctr_drbg);
mbedtls_ssl_conf_authmode(&client_config, MBEDTLS_SSL_VERIFY_NONE);
return 1;
}
int
rb_setup_ssl_server(const char *cert, const char *keyfile, const char *dhfile)
{
int ret;
mbedtls_x509_crt_init(&x509);
ret = mbedtls_x509_crt_parse_file(&x509, cert);
if (ret != 0)
{
rb_lib_log("rb_setup_ssl_server: failed to parse certificate '%s': -0x%x", cert, -ret);
return 0;
}
mbedtls_pk_init(&serv_pk);
ret = mbedtls_pk_parse_keyfile(&serv_pk, keyfile, NULL);
if (ret != 0)
{
rb_lib_log("rb_setup_ssl_server: failed to parse private key '%s': -0x%x", keyfile, -ret);
return 0;
}
mbedtls_dhm_init(&dh_params);
ret = mbedtls_dhm_parse_dhmfile(&dh_params, dhfile);
if (ret != 0)
{
rb_lib_log("rb_setup_ssl_server: failed to parse DH parameters '%s': -0x%x", dhfile, -ret);
return 0;
}
ret = mbedtls_ssl_conf_dh_param_ctx(&serv_config, &dh_params);
if (ret != 0)
{
rb_lib_log("rb_setup_ssl_server: failed to set DH parameters on SSL config context: -0x%x", -ret);
return 0;
}
if (x509.next)
{
mbedtls_ssl_conf_ca_chain(&serv_config, x509.next, NULL);
mbedtls_ssl_conf_ca_chain(&client_config, x509.next, NULL);
}
if ((ret = mbedtls_ssl_conf_own_cert(&serv_config, &x509, &serv_pk)) != 0)
{
rb_lib_log("rb_setup_ssl_server: failed to set up own certificate: -0x%x", -ret);
return 0;
}
if ((ret = mbedtls_ssl_conf_own_cert(&client_config, &x509, &serv_pk)) != 0)
{
rb_lib_log("rb_setup_ssl_server: failed to set up own certificate: -0x%x", -ret);
return 0;
}
return 1;
}
int
rb_ssl_listen(rb_fde_t *F, int backlog, int defer_accept)
{
int result;
result = rb_listen(F, backlog, defer_accept);
F->type = RB_FD_SOCKET | RB_FD_LISTEN | RB_FD_SSL;
return result;
}
struct ssl_connect
{
CNCB *callback;
void *data;
int timeout;
};
static void
rb_ssl_connect_realcb(rb_fde_t *F, int status, struct ssl_connect *sconn)
{
F->connect->callback = sconn->callback;
F->connect->data = sconn->data;
rb_free(sconn);
rb_connect_callback(F, status);
}
static void
rb_ssl_tryconn_timeout_cb(rb_fde_t *F, void *data)
{
rb_ssl_connect_realcb(F, RB_ERR_TIMEOUT, data);
}
static void
rb_ssl_tryconn_cb(rb_fde_t *F, void *data)
{
struct ssl_connect *sconn = data;
int ret;
ret = do_ssl_handshake(F, rb_ssl_tryconn_cb, (void *)sconn);
switch (ret)
{
case -1:
rb_ssl_connect_realcb(F, RB_ERROR_SSL, sconn);
break;
case 0:
/* do_ssl_handshake does the rb_setselect stuff */
return;
default:
break;
}
rb_ssl_connect_realcb(F, RB_OK, sconn);
}
static void
rb_ssl_setup_client_context(rb_fde_t *F, mbedtls_ssl_context *ssl)
{
int ret;
mbedtls_ssl_init(ssl);
if ((ret = mbedtls_ssl_setup(ssl, &client_config)) != 0)
{
rb_lib_log("rb_ssl_setup_client_context: failed to set up ssl context: -0x%x", -ret);
rb_close(F);
return;
}
mbedtls_ssl_set_bio(ssl, F, rb_ssl_write_cb, rb_ssl_read_cb, NULL);
}
static void
rb_ssl_tryconn(rb_fde_t *F, int status, void *data)
{
struct ssl_connect *sconn = data;
if(status != RB_OK)
{
rb_ssl_connect_realcb(F, status, sconn);
return;
}
F->type |= RB_FD_SSL;
rb_settimeout(F, sconn->timeout, rb_ssl_tryconn_timeout_cb, sconn);
F->ssl = rb_malloc(sizeof(mbedtls_ssl_context));
rb_ssl_setup_client_context(F, F->ssl);
do_ssl_handshake(F, rb_ssl_tryconn_cb, (void *)sconn);
}
void
rb_connect_tcp_ssl(rb_fde_t *F, struct sockaddr *dest,
struct sockaddr *clocal, int socklen, CNCB * callback, void *data, int timeout)
{
struct ssl_connect *sconn;
if(F == NULL)
return;
sconn = rb_malloc(sizeof(struct ssl_connect));
sconn->data = data;
sconn->callback = callback;
sconn->timeout = timeout;
rb_connect_tcp(F, dest, clocal, socklen, rb_ssl_tryconn, sconn, timeout);
}
void
rb_ssl_start_connected(rb_fde_t *F, CNCB * callback, void *data, int timeout)
{
struct ssl_connect *sconn;
if(F == NULL)
return;
sconn = rb_malloc(sizeof(struct ssl_connect));
sconn->data = data;
sconn->callback = callback;
sconn->timeout = timeout;
F->connect = rb_malloc(sizeof(struct conndata));
F->connect->callback = callback;
F->connect->data = data;
F->type |= RB_FD_SSL;
F->ssl = rb_malloc(sizeof(mbedtls_ssl_context));
rb_ssl_setup_client_context(F, F->ssl);
rb_settimeout(F, sconn->timeout, rb_ssl_tryconn_timeout_cb, sconn);
do_ssl_handshake(F, rb_ssl_tryconn_cb, (void *)sconn);
}
int
rb_init_prng(const char *path, prng_seed_t seed_type)
{
return 1;
}
int
rb_get_random(void *buf, size_t length)
{
if (mbedtls_ctr_drbg_random(&ctr_drbg, buf, length))
return 0;
return 1;
}
const char *
rb_get_ssl_strerror(rb_fde_t *F)
{
#ifdef MBEDTLS_ERROR_C
static char errbuf[512];
mbedtls_strerror(F->ssl_errno, errbuf, sizeof errbuf);
return errbuf;
#else
return "???";
#endif
}
int
rb_get_ssl_certfp(rb_fde_t *F, uint8_t certfp[RB_SSL_CERTFP_LEN], int method)
{
const mbedtls_x509_crt *peer_cert;
uint8_t hash[RB_SSL_CERTFP_LEN];
size_t hashlen;
const mbedtls_md_info_t *md_info;
mbedtls_md_type_t md_type;
int ret;
switch (method)
{
case RB_SSL_CERTFP_METH_SHA1:
md_type = MBEDTLS_MD_SHA1;
hashlen = RB_SSL_CERTFP_LEN_SHA1;
case RB_SSL_CERTFP_METH_SHA256:
md_type = MBEDTLS_MD_SHA256;
hashlen = RB_SSL_CERTFP_LEN_SHA256;
case RB_SSL_CERTFP_METH_SHA512:
md_type = MBEDTLS_MD_SHA512;
hashlen = RB_SSL_CERTFP_LEN_SHA512;
default:
return 0;
}
peer_cert = mbedtls_ssl_get_peer_cert(SSL_P(F));
if (peer_cert == NULL)
return 0;
md_info = mbedtls_md_info_from_type(md_type);
if (md_info == NULL)
return 0;
if ((ret = mbedtls_md(md_info, peer_cert->raw.p, peer_cert->raw.len, hash)) != 0)
{
rb_lib_log("rb_get_ssl_certfp: unable to get certfp for F: %p, -0x%x", -ret);
return 0;
}
memcpy(certfp, hash, hashlen);
return 1;
}
int
rb_supports_ssl(void)
{
return 1;
}
void
rb_get_ssl_info(char *buf, size_t len)
{
char version_str[512];
mbedtls_version_get_string(version_str);
rb_snprintf(buf, len, "MBEDTLS: compiled (%s), library(%s)",
MBEDTLS_VERSION_STRING, version_str);
}
#endif /* HAVE_GNUTLS */