kcf.c revision fe2f74680a9b0a4c22a80f5da91700cd48e715fe
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Core KCF (Kernel Cryptographic Framework). This file implements
* the loadable module entry points and module verification routines.
*/
#include <sys/systm.h>
#include <sys/cmn_err.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/modctl.h>
#include <sys/errno.h>
#include <sys/rwlock.h>
#include <sys/kmem.h>
#include <sys/door.h>
#include <sys/kobj.h>
#include <sys/crypto/common.h>
#include <sys/crypto/api.h>
#include <sys/crypto/spi.h>
#include <sys/crypto/impl.h>
#include <sys/crypto/sched_impl.h>
#include <sys/crypto/elfsign.h>
#ifdef DEBUG
int kcf_frmwrk_debug = 0;
#define KCF_FRMWRK_DEBUG(l, x) if (kcf_frmwrk_debug >= l) printf x
#else /* DEBUG */
#define KCF_FRMWRK_DEBUG(l, x)
#endif /* DEBUG */
/*
* Door to make upcalls to kcfd. kcfd will send us this
* handle when it is coming up.
*/
kmutex_t kcf_dh_lock;
door_handle_t kcf_dh = NULL;
static struct modlmisc modlmisc = {
&mod_miscops, "Kernel Crypto Framework %I%"
};
static struct modlinkage modlinkage = {
MODREV_1, (void *)&modlmisc, NULL
};
static int rngtimer_started;
int
_init()
{
/* initialize the mechanisms tables supported out-of-the-box */
kcf_init_mech_tabs();
/* initialize the providers tables */
kcf_prov_tab_init();
/* initialize the policy table */
kcf_policy_tab_init();
/* initialize soft_config_list */
kcf_soft_config_init();
/*
* Initialize scheduling structures. Note that this does NOT
* start any threads since it might not be safe to do so.
*/
kcf_sched_init();
/* initialize the RNG support structures */
rngtimer_started = 0;
kcf_rnd_init();
return (mod_install(&modlinkage));
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
/*
* We do not allow kcf to unload.
*/
int
_fini(void)
{
return (EBUSY);
}
/*
* Return a pointer to the modctl structure of the
* provider's module.
*/
struct modctl *
kcf_get_modctl(crypto_provider_info_t *pinfo)
{
struct modctl *mctlp;
/* Get the modctl struct for this module */
if (pinfo->pi_provider_type == CRYPTO_SW_PROVIDER)
mctlp = mod_getctl(pinfo->pi_provider_dev.pd_sw);
else {
major_t major;
char *drvmod;
if ((major =
ddi_driver_major(pinfo->pi_provider_dev.pd_hw)) != -1) {
drvmod = ddi_major_to_name(major);
mctlp = mod_find_by_filename("drv", drvmod);
} else
return (NULL);
}
return (mctlp);
}
/*
* Check if signature verification is needed for a provider.
*
* Returns 0, if no verification is needed. Returns 1, if
* verification is needed. Returns -1, if there is an
* error.
*/
int
kcf_need_signature_verification(kcf_provider_desc_t *pd)
{
struct module *mp;
struct modctl *mctlp = pd->pd_mctlp;
crypto_ops_t *prov_ops = pd->pd_ops_vector;
if (pd->pd_prov_type == CRYPTO_LOGICAL_PROVIDER)
return (0);
if (mctlp == NULL || mctlp->mod_mp == NULL)
return (-1);
mp = (struct module *)mctlp->mod_mp;
/*
* Check if this provider needs to be verified. We always verify
* the module if it carries a signature. Any operation set which has
* a encryption/decryption component is a candidate for verification.
*/
if (prov_ops->co_cipher_ops == NULL && prov_ops->co_dual_ops == NULL &&
prov_ops->co_dual_cipher_mac_ops == NULL &&
prov_ops->co_key_ops == NULL && prov_ops->co_sign_ops == NULL &&
prov_ops->co_verify_ops == NULL && mp->sigdata == NULL) {
return (0);
}
/*
* See if this module has a proper signature section.
*/
if (mp->sigdata == NULL) {
return (-1);
}
mutex_enter(&pd->pd_lock);
pd->pd_state = KCF_PROV_UNVERIFIED;
mutex_exit(&pd->pd_lock);
return (1);
}
/*
* Do the signature verification on the given module. This function can
* be called from user context or kernel context.
*
* We call kcfd with the full pathname of the module to be
* verified. kcfd will return success/restricted/fail, signature length
* and the actual signature in the ELF section of the module. If kcfd
* returns success or restricted, we compare the signature and the length
* with the values that krtld stored in the module structure. We log an
* error message in case of a failure.
*
* The provider state is changed to KCF_PROV_READY on success.
*/
void
kcf_verify_signature(void *arg)
{
int rv;
int error = CRYPTO_MODVERIFICATION_FAILED;
door_arg_t darg;
door_handle_t ldh;
kcf_door_arg_t *kda;
char *filename;
kcf_provider_desc_t *pd = arg;
struct module *mp;
boolean_t do_notify = B_FALSE;
boolean_t modhold_done = B_FALSE;
struct modctl *mctlp = pd->pd_mctlp;
ASSERT(pd->pd_prov_type != CRYPTO_LOGICAL_PROVIDER);
ASSERT(mctlp != NULL);
for (;;) {
mutex_enter(&pd->pd_lock);
/* No need to do verification */
if (pd->pd_state != KCF_PROV_UNVERIFIED) {
mutex_exit(&pd->pd_lock);
goto out;
}
mutex_exit(&pd->pd_lock);
mutex_enter(&mod_lock);
if (mctlp->mod_mp == NULL) {
mutex_exit(&mod_lock);
goto out;
}
/*
* This check is needed since a software provider can call
* us directly from the _init->crypto_register_provider path.
*/
if (pd->pd_prov_type == CRYPTO_SW_PROVIDER &&
mctlp->mod_inprogress_thread == curthread) {
mutex_exit(&mod_lock);
modhold_done = B_FALSE;
break;
}
/*
* We could be in a race with the register thread or
* the unregister thread. So, retry if register or
* unregister is in progress. Note that we can't do
* mod_hold_by_modctl without this check since that
* could result in a deadlock with the other threads.
*/
if (mctlp->mod_busy) {
mutex_exit(&mod_lock);
/* delay for 10ms and try again */
delay(drv_usectohz(10000));
continue;
}
(void) mod_hold_by_modctl(mctlp,
MOD_WAIT_FOREVER | MOD_LOCK_HELD);
mutex_exit(&mod_lock);
modhold_done = B_TRUE;
break;
}
/*
* Check if the door is set up yet. This will be set when kcfd
* comes up. If not, we return and leave the provider state unchanged
* at KCF_PROV_UNVERIFIED. This will trigger the verification of
* the module later when kcfd is up. This is safe as we NEVER use
* a provider that has not been verified yet.
*/
mutex_enter(&kcf_dh_lock);
if (kcf_dh == NULL) {
mutex_exit(&kcf_dh_lock);
goto out;
}
ldh = kcf_dh;
door_ki_hold(ldh);
mutex_exit(&kcf_dh_lock);
mp = (struct module *)mctlp->mod_mp;
filename = mp->filename;
KCF_FRMWRK_DEBUG(2, ("Verifying module: %s\n", filename));
kda = kmem_alloc(sizeof (kcf_door_arg_t) + mp->sigsize, KM_SLEEP);
kda->da_version = KCF_KCFD_VERSION1;
kda->da_iskernel = B_TRUE;
bcopy(filename, kda->da_u.filename, strlen(filename) + 1);
darg.data_ptr = (char *)kda;
darg.data_size = sizeof (kcf_door_arg_t) + mp->sigsize;
darg.desc_ptr = NULL;
darg.desc_num = 0;
darg.rbuf = (char *)kda;
darg.rsize = sizeof (kcf_door_arg_t);
/*
* Make door upcall. door_ki_upcall() checks for validity of the handle.
*/
rv = door_ki_upcall(ldh, &darg);
if (rv == 0) {
kcf_door_arg_t *rkda = (kcf_door_arg_t *)darg.rbuf;
KCF_FRMWRK_DEBUG(2,
("passed: %d\n", rkda->da_u.result.status));
KCF_FRMWRK_DEBUG(2,
("signature length: %d\n", rkda->da_u.result.siglen));
KCF_FRMWRK_DEBUG(2,
("signature: %p\n", (void*)rkda->da_u.result.signature));
/* Check kcfd result and compare against module struct fields */
if (((rkda->da_u.result.status != ELFSIGN_SUCCESS) &&
(rkda->da_u.result.status != ELFSIGN_RESTRICTED)) ||
!(rkda->da_u.result.siglen == mp->sigsize) ||
(bcmp(rkda->da_u.result.signature, mp->sigdata,
mp->sigsize))) {
cmn_err(CE_WARN, "Module verification failed for %s.",
filename);
} else {
error = 0;
}
if (rkda->da_u.result.status == ELFSIGN_RESTRICTED) {
pd->pd_flags |= KCF_PROV_RESTRICTED;
KCF_FRMWRK_DEBUG(2, ("provider is restricted\n"));
}
if (rkda != kda)
kmem_free(rkda, darg.rsize);
} else {
cmn_err(CE_WARN, "Module verification door upcall failed "
"for %s. errno = %d", filename, rv);
}
kmem_free(kda, sizeof (kcf_door_arg_t) + mp->sigsize);
door_ki_rele(ldh);
mutex_enter(&pd->pd_lock);
/* change state only if the original state is unchanged */
if (pd->pd_state == KCF_PROV_UNVERIFIED) {
if (error == 0) {
pd->pd_state = KCF_PROV_READY;
do_notify = B_TRUE;
} else {
pd->pd_state = KCF_PROV_VERIFICATION_FAILED;
}
}
mutex_exit(&pd->pd_lock);
if (do_notify) {
/* Dispatch events for this new provider */
kcf_do_notify(pd, B_TRUE);
}
out:
if (modhold_done)
mod_release_mod(mctlp);
KCF_PROV_IREFRELE(pd);
KCF_PROV_REFRELE(pd);
}
/* called from the CRYPTO_LOAD_DOOR ioctl */
int
crypto_load_door(uint_t did)
{
mutex_enter(&kcf_dh_lock);
kcf_dh = door_ki_lookup(did);
mutex_exit(&kcf_dh_lock);
verify_unverified_providers();
/* Start the timeout handler to get random numbers */
if (rngtimer_started == 0) {
kcf_rnd_schedule_timeout(B_TRUE);
rngtimer_started = 1;
}
return (0);
}