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freebsd-nq/sys/geom/eli/g_eli.c
Allan Jude ec5c0e5be9 Implement boot-time encryption key passing (keybuf) 
This patch adds a general mechanism for providing encryption keys to the
kernel from the boot loader. This is intended to enable GELI support at
boot time, providing a better mechanism for passing keys to the kernel
than environment variables. It is designed to be extensible to other
applications, and can easily handle multiple encrypted volumes with
different keys.

This mechanism is currently used by the pending GELI EFI work.
Additionally, this mechanism can potentially be used to interface with
GRUB, opening up options for coreboot+GRUB configurations with completely
encrypted disks.

Another benefit over the existing system is that it does not require
re-deriving the user key from the password at each boot stage.

Most of this patch was written by Eric McCorkle. It was extended by
Allan Jude with a number of minor enhancements and extending the keybuf
feature into boot2.

GELI user keys are now derived once, in boot2, then passed to the loader,
which reuses the key, then passes it to the kernel, where the GELI module
destroys the keybuf after decrypting the volumes.

Submitted by:	Eric McCorkle <eric@metricspace.net> (Original Version)
Reviewed by:	oshogbo (earlier version), cem (earlier version)
MFC after:	3 weeks
Relnotes:	yes
Sponsored by:	ScaleEngine Inc.
Differential Revision:	https://reviews.freebsd.org/D9575
2017-04-01 05:05:22 +00:00

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/*-
* Copyright (c) 2005-2011 Pawel Jakub Dawidek <pawel@dawidek.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/cons.h>
#include <sys/kernel.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/bio.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/eventhandler.h>
#include <sys/kthread.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <vm/uma.h>
#include <geom/geom.h>
#include <geom/eli/g_eli.h>
#include <geom/eli/pkcs5v2.h>
#include <crypto/intake.h>
FEATURE(geom_eli, "GEOM crypto module");
MALLOC_DEFINE(M_ELI, "eli data", "GEOM_ELI Data");
SYSCTL_DECL(_kern_geom);
SYSCTL_NODE(_kern_geom, OID_AUTO, eli, CTLFLAG_RW, 0, "GEOM_ELI stuff");
static int g_eli_version = G_ELI_VERSION;
SYSCTL_INT(_kern_geom_eli, OID_AUTO, version, CTLFLAG_RD, &g_eli_version, 0,
"GELI version");
int g_eli_debug = 0;
SYSCTL_INT(_kern_geom_eli, OID_AUTO, debug, CTLFLAG_RWTUN, &g_eli_debug, 0,
"Debug level");
static u_int g_eli_tries = 3;
SYSCTL_UINT(_kern_geom_eli, OID_AUTO, tries, CTLFLAG_RWTUN, &g_eli_tries, 0,
"Number of tries for entering the passphrase");
static u_int g_eli_visible_passphrase = GETS_NOECHO;
SYSCTL_UINT(_kern_geom_eli, OID_AUTO, visible_passphrase, CTLFLAG_RWTUN,
&g_eli_visible_passphrase, 0,
"Visibility of passphrase prompt (0 = invisible, 1 = visible, 2 = asterisk)");
u_int g_eli_overwrites = G_ELI_OVERWRITES;
SYSCTL_UINT(_kern_geom_eli, OID_AUTO, overwrites, CTLFLAG_RWTUN, &g_eli_overwrites,
0, "Number of times on-disk keys should be overwritten when destroying them");
static u_int g_eli_threads = 0;
SYSCTL_UINT(_kern_geom_eli, OID_AUTO, threads, CTLFLAG_RWTUN, &g_eli_threads, 0,
"Number of threads doing crypto work");
u_int g_eli_batch = 0;
SYSCTL_UINT(_kern_geom_eli, OID_AUTO, batch, CTLFLAG_RWTUN, &g_eli_batch, 0,
"Use crypto operations batching");
/*
* Passphrase cached during boot, in order to be more user-friendly if
* there are multiple providers using the same passphrase.
*/
static char cached_passphrase[256];
static u_int g_eli_boot_passcache = 1;
TUNABLE_INT("kern.geom.eli.boot_passcache", &g_eli_boot_passcache);
SYSCTL_UINT(_kern_geom_eli, OID_AUTO, boot_passcache, CTLFLAG_RD,
&g_eli_boot_passcache, 0,
"Passphrases are cached during boot process for possible reuse");
static void
fetch_loader_passphrase(void * dummy)
{
char * env_passphrase;
KASSERT(dynamic_kenv, ("need dynamic kenv"));
if ((env_passphrase = kern_getenv("kern.geom.eli.passphrase")) != NULL) {
/* Extract passphrase from the environment. */
strlcpy(cached_passphrase, env_passphrase,
sizeof(cached_passphrase));
freeenv(env_passphrase);
/* Wipe the passphrase from the environment. */
kern_unsetenv("kern.geom.eli.passphrase");
}
}
SYSINIT(geli_fetch_loader_passphrase, SI_SUB_KMEM + 1, SI_ORDER_ANY,
fetch_loader_passphrase, NULL);
static void
zero_boot_passcache(void)
{
explicit_bzero(cached_passphrase, sizeof(cached_passphrase));
}
static void
zero_geli_intake_keys(void)
{
struct keybuf *keybuf;
int i;
if ((keybuf = get_keybuf()) != NULL) {
/* Scan the key buffer, clear all GELI keys. */
for (i = 0; i < keybuf->kb_nents; i++) {
if (keybuf->kb_ents[i].ke_type == KEYBUF_TYPE_GELI) {
explicit_bzero(keybuf->kb_ents[i].ke_data,
sizeof(keybuf->kb_ents[i].ke_data));
keybuf->kb_ents[i].ke_type = KEYBUF_TYPE_NONE;
}
}
}
}
static void
zero_intake_passcache(void *dummy)
{
zero_boot_passcache();
zero_geli_intake_keys();
}
EVENTHANDLER_DEFINE(mountroot, zero_intake_passcache, NULL, 0);
static eventhandler_tag g_eli_pre_sync = NULL;
static int g_eli_destroy_geom(struct gctl_req *req, struct g_class *mp,
struct g_geom *gp);
static void g_eli_init(struct g_class *mp);
static void g_eli_fini(struct g_class *mp);
static g_taste_t g_eli_taste;
static g_dumpconf_t g_eli_dumpconf;
struct g_class g_eli_class = {
.name = G_ELI_CLASS_NAME,
.version = G_VERSION,
.ctlreq = g_eli_config,
.taste = g_eli_taste,
.destroy_geom = g_eli_destroy_geom,
.init = g_eli_init,
.fini = g_eli_fini
};
/*
* Code paths:
* BIO_READ:
* g_eli_start -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> g_eli_crypto_read_done -> g_io_deliver
* BIO_WRITE:
* g_eli_start -> g_eli_crypto_run -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
*/
/*
* EAGAIN from crypto(9) means, that we were probably balanced to another crypto
* accelerator or something like this.
* The function updates the SID and rerun the operation.
*/
int
g_eli_crypto_rerun(struct cryptop *crp)
{
struct g_eli_softc *sc;
struct g_eli_worker *wr;
struct bio *bp;
int error;
bp = (struct bio *)crp->crp_opaque;
sc = bp->bio_to->geom->softc;
LIST_FOREACH(wr, &sc->sc_workers, w_next) {
if (wr->w_number == bp->bio_pflags)
break;
}
KASSERT(wr != NULL, ("Invalid worker (%u).", bp->bio_pflags));
G_ELI_DEBUG(1, "Rerunning crypto %s request (sid: %ju -> %ju).",
bp->bio_cmd == BIO_READ ? "READ" : "WRITE", (uintmax_t)wr->w_sid,
(uintmax_t)crp->crp_sid);
wr->w_sid = crp->crp_sid;
crp->crp_etype = 0;
error = crypto_dispatch(crp);
if (error == 0)
return (0);
G_ELI_DEBUG(1, "%s: crypto_dispatch() returned %d.", __func__, error);
crp->crp_etype = error;
return (error);
}
/*
* The function is called afer reading encrypted data from the provider.
*
* g_eli_start -> g_eli_crypto_read -> g_io_request -> G_ELI_READ_DONE -> g_eli_crypto_run -> g_eli_crypto_read_done -> g_io_deliver
*/
void
g_eli_read_done(struct bio *bp)
{
struct g_eli_softc *sc;
struct bio *pbp;
G_ELI_LOGREQ(2, bp, "Request done.");
pbp = bp->bio_parent;
if (pbp->bio_error == 0 && bp->bio_error != 0)
pbp->bio_error = bp->bio_error;
g_destroy_bio(bp);
/*
* Do we have all sectors already?
*/
pbp->bio_inbed++;
if (pbp->bio_inbed < pbp->bio_children)
return;
sc = pbp->bio_to->geom->softc;
if (pbp->bio_error != 0) {
G_ELI_LOGREQ(0, pbp, "%s() failed (error=%d)", __func__,
pbp->bio_error);
pbp->bio_completed = 0;
if (pbp->bio_driver2 != NULL) {
free(pbp->bio_driver2, M_ELI);
pbp->bio_driver2 = NULL;
}
g_io_deliver(pbp, pbp->bio_error);
atomic_subtract_int(&sc->sc_inflight, 1);
return;
}
mtx_lock(&sc->sc_queue_mtx);
bioq_insert_tail(&sc->sc_queue, pbp);
mtx_unlock(&sc->sc_queue_mtx);
wakeup(sc);
}
/*
* The function is called after we encrypt and write data.
*
* g_eli_start -> g_eli_crypto_run -> g_eli_crypto_write_done -> g_io_request -> G_ELI_WRITE_DONE -> g_io_deliver
*/
void
g_eli_write_done(struct bio *bp)
{
struct g_eli_softc *sc;
struct bio *pbp;
G_ELI_LOGREQ(2, bp, "Request done.");
pbp = bp->bio_parent;
if (pbp->bio_error == 0 && bp->bio_error != 0)
pbp->bio_error = bp->bio_error;
g_destroy_bio(bp);
/*
* Do we have all sectors already?
*/
pbp->bio_inbed++;
if (pbp->bio_inbed < pbp->bio_children)
return;
free(pbp->bio_driver2, M_ELI);
pbp->bio_driver2 = NULL;
if (pbp->bio_error != 0) {
G_ELI_LOGREQ(0, pbp, "%s() failed (error=%d)", __func__,
pbp->bio_error);
pbp->bio_completed = 0;
} else
pbp->bio_completed = pbp->bio_length;
/*
* Write is finished, send it up.
*/
sc = pbp->bio_to->geom->softc;
g_io_deliver(pbp, pbp->bio_error);
atomic_subtract_int(&sc->sc_inflight, 1);
}
/*
* This function should never be called, but GEOM made as it set ->orphan()
* method for every geom.
*/
static void
g_eli_orphan_spoil_assert(struct g_consumer *cp)
{
panic("Function %s() called for %s.", __func__, cp->geom->name);
}
static void
g_eli_orphan(struct g_consumer *cp)
{
struct g_eli_softc *sc;
g_topology_assert();
sc = cp->geom->softc;
if (sc == NULL)
return;
g_eli_destroy(sc, TRUE);
}
/*
* BIO_READ:
* G_ELI_START -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> g_eli_crypto_read_done -> g_io_deliver
* BIO_WRITE:
* G_ELI_START -> g_eli_crypto_run -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
*/
static void
g_eli_start(struct bio *bp)
{
struct g_eli_softc *sc;
struct g_consumer *cp;
struct bio *cbp;
sc = bp->bio_to->geom->softc;
KASSERT(sc != NULL,
("Provider's error should be set (error=%d)(device=%s).",
bp->bio_to->error, bp->bio_to->name));
G_ELI_LOGREQ(2, bp, "Request received.");
switch (bp->bio_cmd) {
case BIO_READ:
case BIO_WRITE:
case BIO_GETATTR:
case BIO_FLUSH:
case BIO_ZONE:
break;
case BIO_DELETE:
/*
* If the user hasn't set the NODELETE flag, we just pass
* it down the stack and let the layers beneath us do (or
* not) whatever they do with it. If they have, we
* reject it. A possible extension would be an
* additional flag to take it as a hint to shred the data
* with [multiple?] overwrites.
*/
if (!(sc->sc_flags & G_ELI_FLAG_NODELETE))
break;
default:
g_io_deliver(bp, EOPNOTSUPP);
return;
}
cbp = g_clone_bio(bp);
if (cbp == NULL) {
g_io_deliver(bp, ENOMEM);
return;
}
bp->bio_driver1 = cbp;
bp->bio_pflags = G_ELI_NEW_BIO;
switch (bp->bio_cmd) {
case BIO_READ:
if (!(sc->sc_flags & G_ELI_FLAG_AUTH)) {
g_eli_crypto_read(sc, bp, 0);
break;
}
/* FALLTHROUGH */
case BIO_WRITE:
mtx_lock(&sc->sc_queue_mtx);
bioq_insert_tail(&sc->sc_queue, bp);
mtx_unlock(&sc->sc_queue_mtx);
wakeup(sc);
break;
case BIO_GETATTR:
case BIO_FLUSH:
case BIO_DELETE:
case BIO_ZONE:
cbp->bio_done = g_std_done;
cp = LIST_FIRST(&sc->sc_geom->consumer);
cbp->bio_to = cp->provider;
G_ELI_LOGREQ(2, cbp, "Sending request.");
g_io_request(cbp, cp);
break;
}
}
static int
g_eli_newsession(struct g_eli_worker *wr)
{
struct g_eli_softc *sc;
struct cryptoini crie, cria;
int error;
sc = wr->w_softc;
bzero(&crie, sizeof(crie));
crie.cri_alg = sc->sc_ealgo;
crie.cri_klen = sc->sc_ekeylen;
if (sc->sc_ealgo == CRYPTO_AES_XTS)
crie.cri_klen <<= 1;
if ((sc->sc_flags & G_ELI_FLAG_FIRST_KEY) != 0) {
crie.cri_key = g_eli_key_hold(sc, 0,
LIST_FIRST(&sc->sc_geom->consumer)->provider->sectorsize);
} else {
crie.cri_key = sc->sc_ekey;
}
if (sc->sc_flags & G_ELI_FLAG_AUTH) {
bzero(&cria, sizeof(cria));
cria.cri_alg = sc->sc_aalgo;
cria.cri_klen = sc->sc_akeylen;
cria.cri_key = sc->sc_akey;
crie.cri_next = &cria;
}
switch (sc->sc_crypto) {
case G_ELI_CRYPTO_SW:
error = crypto_newsession(&wr->w_sid, &crie,
CRYPTOCAP_F_SOFTWARE);
break;
case G_ELI_CRYPTO_HW:
error = crypto_newsession(&wr->w_sid, &crie,
CRYPTOCAP_F_HARDWARE);
break;
case G_ELI_CRYPTO_UNKNOWN:
error = crypto_newsession(&wr->w_sid, &crie,
CRYPTOCAP_F_HARDWARE);
if (error == 0) {
mtx_lock(&sc->sc_queue_mtx);
if (sc->sc_crypto == G_ELI_CRYPTO_UNKNOWN)
sc->sc_crypto = G_ELI_CRYPTO_HW;
mtx_unlock(&sc->sc_queue_mtx);
} else {
error = crypto_newsession(&wr->w_sid, &crie,
CRYPTOCAP_F_SOFTWARE);
mtx_lock(&sc->sc_queue_mtx);
if (sc->sc_crypto == G_ELI_CRYPTO_UNKNOWN)
sc->sc_crypto = G_ELI_CRYPTO_SW;
mtx_unlock(&sc->sc_queue_mtx);
}
break;
default:
panic("%s: invalid condition", __func__);
}
if ((sc->sc_flags & G_ELI_FLAG_FIRST_KEY) != 0)
g_eli_key_drop(sc, crie.cri_key);
return (error);
}
static void
g_eli_freesession(struct g_eli_worker *wr)
{
crypto_freesession(wr->w_sid);
}
static void
g_eli_cancel(struct g_eli_softc *sc)
{
struct bio *bp;
mtx_assert(&sc->sc_queue_mtx, MA_OWNED);
while ((bp = bioq_takefirst(&sc->sc_queue)) != NULL) {
KASSERT(bp->bio_pflags == G_ELI_NEW_BIO,
("Not new bio when canceling (bp=%p).", bp));
g_io_deliver(bp, ENXIO);
}
}
static struct bio *
g_eli_takefirst(struct g_eli_softc *sc)
{
struct bio *bp;
mtx_assert(&sc->sc_queue_mtx, MA_OWNED);
if (!(sc->sc_flags & G_ELI_FLAG_SUSPEND))
return (bioq_takefirst(&sc->sc_queue));
/*
* Device suspended, so we skip new I/O requests.
*/
TAILQ_FOREACH(bp, &sc->sc_queue.queue, bio_queue) {
if (bp->bio_pflags != G_ELI_NEW_BIO)
break;
}
if (bp != NULL)
bioq_remove(&sc->sc_queue, bp);
return (bp);
}
/*
* This is the main function for kernel worker thread when we don't have
* hardware acceleration and we have to do cryptography in software.
* Dedicated thread is needed, so we don't slow down g_up/g_down GEOM
* threads with crypto work.
*/
static void
g_eli_worker(void *arg)
{
struct g_eli_softc *sc;
struct g_eli_worker *wr;
struct bio *bp;
int error;
wr = arg;
sc = wr->w_softc;
#ifdef EARLY_AP_STARTUP
MPASS(!sc->sc_cpubind || smp_started);
#elif defined(SMP)
/* Before sched_bind() to a CPU, wait for all CPUs to go on-line. */
if (sc->sc_cpubind) {
while (!smp_started)
tsleep(wr, 0, "geli:smp", hz / 4);
}
#endif
thread_lock(curthread);
sched_prio(curthread, PUSER);
if (sc->sc_cpubind)
sched_bind(curthread, wr->w_number % mp_ncpus);
thread_unlock(curthread);
G_ELI_DEBUG(1, "Thread %s started.", curthread->td_proc->p_comm);
for (;;) {
mtx_lock(&sc->sc_queue_mtx);
again:
bp = g_eli_takefirst(sc);
if (bp == NULL) {
if (sc->sc_flags & G_ELI_FLAG_DESTROY) {
g_eli_cancel(sc);
LIST_REMOVE(wr, w_next);
g_eli_freesession(wr);
free(wr, M_ELI);
G_ELI_DEBUG(1, "Thread %s exiting.",
curthread->td_proc->p_comm);
wakeup(&sc->sc_workers);
mtx_unlock(&sc->sc_queue_mtx);
kproc_exit(0);
}
while (sc->sc_flags & G_ELI_FLAG_SUSPEND) {
if (sc->sc_inflight > 0) {
G_ELI_DEBUG(0, "inflight=%d",
sc->sc_inflight);
/*
* We still have inflight BIOs, so
* sleep and retry.
*/
msleep(sc, &sc->sc_queue_mtx, PRIBIO,
"geli:inf", hz / 5);
goto again;
}
/*
* Suspend requested, mark the worker as
* suspended and go to sleep.
*/
if (wr->w_active) {
g_eli_freesession(wr);
wr->w_active = FALSE;
}
wakeup(&sc->sc_workers);
msleep(sc, &sc->sc_queue_mtx, PRIBIO,
"geli:suspend", 0);
if (!wr->w_active &&
!(sc->sc_flags & G_ELI_FLAG_SUSPEND)) {
error = g_eli_newsession(wr);
KASSERT(error == 0,
("g_eli_newsession() failed on resume (error=%d)",
error));
wr->w_active = TRUE;
}
goto again;
}
msleep(sc, &sc->sc_queue_mtx, PDROP, "geli:w", 0);
continue;
}
if (bp->bio_pflags == G_ELI_NEW_BIO)
atomic_add_int(&sc->sc_inflight, 1);
mtx_unlock(&sc->sc_queue_mtx);
if (bp->bio_pflags == G_ELI_NEW_BIO) {
bp->bio_pflags = 0;
if (sc->sc_flags & G_ELI_FLAG_AUTH) {
if (bp->bio_cmd == BIO_READ)
g_eli_auth_read(sc, bp);
else
g_eli_auth_run(wr, bp);
} else {
if (bp->bio_cmd == BIO_READ)
g_eli_crypto_read(sc, bp, 1);
else
g_eli_crypto_run(wr, bp);
}
} else {
if (sc->sc_flags & G_ELI_FLAG_AUTH)
g_eli_auth_run(wr, bp);
else
g_eli_crypto_run(wr, bp);
}
}
}
int
g_eli_read_metadata(struct g_class *mp, struct g_provider *pp,
struct g_eli_metadata *md)
{
struct g_geom *gp;
struct g_consumer *cp;
u_char *buf = NULL;
int error;
g_topology_assert();
gp = g_new_geomf(mp, "eli:taste");
gp->start = g_eli_start;
gp->access = g_std_access;
/*
* g_eli_read_metadata() is always called from the event thread.
* Our geom is created and destroyed in the same event, so there
* could be no orphan nor spoil event in the meantime.
*/
gp->orphan = g_eli_orphan_spoil_assert;
gp->spoiled = g_eli_orphan_spoil_assert;
cp = g_new_consumer(gp);
error = g_attach(cp, pp);
if (error != 0)
goto end;
error = g_access(cp, 1, 0, 0);
if (error != 0)
goto end;
g_topology_unlock();
buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
&error);
g_topology_lock();
if (buf == NULL)
goto end;
error = eli_metadata_decode(buf, md);
if (error != 0)
goto end;
/* Metadata was read and decoded successfully. */
end:
if (buf != NULL)
g_free(buf);
if (cp->provider != NULL) {
if (cp->acr == 1)
g_access(cp, -1, 0, 0);
g_detach(cp);
}
g_destroy_consumer(cp);
g_destroy_geom(gp);
return (error);
}
/*
* The function is called when we had last close on provider and user requested
* to close it when this situation occur.
*/
static void
g_eli_last_close(void *arg, int flags __unused)
{
struct g_geom *gp;
char gpname[64];
int error;
g_topology_assert();
gp = arg;
strlcpy(gpname, gp->name, sizeof(gpname));
error = g_eli_destroy(gp->softc, TRUE);
KASSERT(error == 0, ("Cannot detach %s on last close (error=%d).",
gpname, error));
G_ELI_DEBUG(0, "Detached %s on last close.", gpname);
}
int
g_eli_access(struct g_provider *pp, int dr, int dw, int de)
{
struct g_eli_softc *sc;
struct g_geom *gp;
gp = pp->geom;
sc = gp->softc;
if (dw > 0) {
if (sc->sc_flags & G_ELI_FLAG_RO) {
/* Deny write attempts. */
return (EROFS);
}
/* Someone is opening us for write, we need to remember that. */
sc->sc_flags |= G_ELI_FLAG_WOPEN;
return (0);
}
/* Is this the last close? */
if (pp->acr + dr > 0 || pp->acw + dw > 0 || pp->ace + de > 0)
return (0);
/*
* Automatically detach on last close if requested.
*/
if ((sc->sc_flags & G_ELI_FLAG_RW_DETACH) ||
(sc->sc_flags & G_ELI_FLAG_WOPEN)) {
g_post_event(g_eli_last_close, gp, M_WAITOK, NULL);
}
return (0);
}
static int
g_eli_cpu_is_disabled(int cpu)
{
#ifdef SMP
return (CPU_ISSET(cpu, &hlt_cpus_mask));
#else
return (0);
#endif
}
struct g_geom *
g_eli_create(struct gctl_req *req, struct g_class *mp, struct g_provider *bpp,
const struct g_eli_metadata *md, const u_char *mkey, int nkey)
{
struct g_eli_softc *sc;
struct g_eli_worker *wr;
struct g_geom *gp;
struct g_provider *pp;
struct g_consumer *cp;
u_int i, threads;
int error;
G_ELI_DEBUG(1, "Creating device %s%s.", bpp->name, G_ELI_SUFFIX);
gp = g_new_geomf(mp, "%s%s", bpp->name, G_ELI_SUFFIX);
sc = malloc(sizeof(*sc), M_ELI, M_WAITOK | M_ZERO);
gp->start = g_eli_start;
/*
* Spoiling can happen even though we have the provider open
* exclusively, e.g. through media change events.
*/
gp->spoiled = g_eli_orphan;
gp->orphan = g_eli_orphan;
gp->dumpconf = g_eli_dumpconf;
/*
* If detach-on-last-close feature is not enabled and we don't operate
* on read-only provider, we can simply use g_std_access().
*/
if (md->md_flags & (G_ELI_FLAG_WO_DETACH | G_ELI_FLAG_RO))
gp->access = g_eli_access;
else
gp->access = g_std_access;
eli_metadata_softc(sc, md, bpp->sectorsize, bpp->mediasize);
sc->sc_nkey = nkey;
gp->softc = sc;
sc->sc_geom = gp;
bioq_init(&sc->sc_queue);
mtx_init(&sc->sc_queue_mtx, "geli:queue", NULL, MTX_DEF);
mtx_init(&sc->sc_ekeys_lock, "geli:ekeys", NULL, MTX_DEF);
pp = NULL;
cp = g_new_consumer(gp);
error = g_attach(cp, bpp);
if (error != 0) {
if (req != NULL) {
gctl_error(req, "Cannot attach to %s (error=%d).",
bpp->name, error);
} else {
G_ELI_DEBUG(1, "Cannot attach to %s (error=%d).",
bpp->name, error);
}
goto failed;
}
/*
* Keep provider open all the time, so we can run critical tasks,
* like Master Keys deletion, without wondering if we can open
* provider or not.
* We don't open provider for writing only when user requested read-only
* access.
*/
if (sc->sc_flags & G_ELI_FLAG_RO)
error = g_access(cp, 1, 0, 1);
else
error = g_access(cp, 1, 1, 1);
if (error != 0) {
if (req != NULL) {
gctl_error(req, "Cannot access %s (error=%d).",
bpp->name, error);
} else {
G_ELI_DEBUG(1, "Cannot access %s (error=%d).",
bpp->name, error);
}
goto failed;
}
/*
* Remember the keys in our softc structure.
*/
g_eli_mkey_propagate(sc, mkey);
LIST_INIT(&sc->sc_workers);
threads = g_eli_threads;
if (threads == 0)
threads = mp_ncpus;
sc->sc_cpubind = (mp_ncpus > 1 && threads == mp_ncpus);
for (i = 0; i < threads; i++) {
if (g_eli_cpu_is_disabled(i)) {
G_ELI_DEBUG(1, "%s: CPU %u disabled, skipping.",
bpp->name, i);
continue;
}
wr = malloc(sizeof(*wr), M_ELI, M_WAITOK | M_ZERO);
wr->w_softc = sc;
wr->w_number = i;
wr->w_active = TRUE;
error = g_eli_newsession(wr);
if (error != 0) {
free(wr, M_ELI);
if (req != NULL) {
gctl_error(req, "Cannot set up crypto session "
"for %s (error=%d).", bpp->name, error);
} else {
G_ELI_DEBUG(1, "Cannot set up crypto session "
"for %s (error=%d).", bpp->name, error);
}
goto failed;
}
error = kproc_create(g_eli_worker, wr, &wr->w_proc, 0, 0,
"g_eli[%u] %s", i, bpp->name);
if (error != 0) {
g_eli_freesession(wr);
free(wr, M_ELI);
if (req != NULL) {
gctl_error(req, "Cannot create kernel thread "
"for %s (error=%d).", bpp->name, error);
} else {
G_ELI_DEBUG(1, "Cannot create kernel thread "
"for %s (error=%d).", bpp->name, error);
}
goto failed;
}
LIST_INSERT_HEAD(&sc->sc_workers, wr, w_next);
}
/*
* Create decrypted provider.
*/
pp = g_new_providerf(gp, "%s%s", bpp->name, G_ELI_SUFFIX);
pp->mediasize = sc->sc_mediasize;
pp->sectorsize = sc->sc_sectorsize;
g_error_provider(pp, 0);
G_ELI_DEBUG(0, "Device %s created.", pp->name);
G_ELI_DEBUG(0, "Encryption: %s %u", g_eli_algo2str(sc->sc_ealgo),
sc->sc_ekeylen);
if (sc->sc_flags & G_ELI_FLAG_AUTH)
G_ELI_DEBUG(0, " Integrity: %s", g_eli_algo2str(sc->sc_aalgo));
G_ELI_DEBUG(0, " Crypto: %s",
sc->sc_crypto == G_ELI_CRYPTO_SW ? "software" : "hardware");
return (gp);
failed:
mtx_lock(&sc->sc_queue_mtx);
sc->sc_flags |= G_ELI_FLAG_DESTROY;
wakeup(sc);
/*
* Wait for kernel threads self destruction.
*/
while (!LIST_EMPTY(&sc->sc_workers)) {
msleep(&sc->sc_workers, &sc->sc_queue_mtx, PRIBIO,
"geli:destroy", 0);
}
mtx_destroy(&sc->sc_queue_mtx);
if (cp->provider != NULL) {
if (cp->acr == 1)
g_access(cp, -1, -1, -1);
g_detach(cp);
}
g_destroy_consumer(cp);
g_destroy_geom(gp);
g_eli_key_destroy(sc);
bzero(sc, sizeof(*sc));
free(sc, M_ELI);
return (NULL);
}
int
g_eli_destroy(struct g_eli_softc *sc, boolean_t force)
{
struct g_geom *gp;
struct g_provider *pp;
g_topology_assert();
if (sc == NULL)
return (ENXIO);
gp = sc->sc_geom;
pp = LIST_FIRST(&gp->provider);
if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
if (force) {
G_ELI_DEBUG(1, "Device %s is still open, so it "
"cannot be definitely removed.", pp->name);
sc->sc_flags |= G_ELI_FLAG_RW_DETACH;
gp->access = g_eli_access;
g_wither_provider(pp, ENXIO);
return (EBUSY);
} else {
G_ELI_DEBUG(1,
"Device %s is still open (r%dw%de%d).", pp->name,
pp->acr, pp->acw, pp->ace);
return (EBUSY);
}
}
mtx_lock(&sc->sc_queue_mtx);
sc->sc_flags |= G_ELI_FLAG_DESTROY;
wakeup(sc);
while (!LIST_EMPTY(&sc->sc_workers)) {
msleep(&sc->sc_workers, &sc->sc_queue_mtx, PRIBIO,
"geli:destroy", 0);
}
mtx_destroy(&sc->sc_queue_mtx);
gp->softc = NULL;
g_eli_key_destroy(sc);
bzero(sc, sizeof(*sc));
free(sc, M_ELI);
if (pp == NULL || (pp->acr == 0 && pp->acw == 0 && pp->ace == 0))
G_ELI_DEBUG(0, "Device %s destroyed.", gp->name);
g_wither_geom_close(gp, ENXIO);
return (0);
}
static int
g_eli_destroy_geom(struct gctl_req *req __unused,
struct g_class *mp __unused, struct g_geom *gp)
{
struct g_eli_softc *sc;
sc = gp->softc;
return (g_eli_destroy(sc, FALSE));
}
static int
g_eli_keyfiles_load(struct hmac_ctx *ctx, const char *provider)
{
u_char *keyfile, *data;
char *file, name[64];
size_t size;
int i;
for (i = 0; ; i++) {
snprintf(name, sizeof(name), "%s:geli_keyfile%d", provider, i);
keyfile = preload_search_by_type(name);
if (keyfile == NULL && i == 0) {
/*
* If there is only one keyfile, allow simpler name.
*/
snprintf(name, sizeof(name), "%s:geli_keyfile", provider);
keyfile = preload_search_by_type(name);
}
if (keyfile == NULL)
return (i); /* Return number of loaded keyfiles. */
data = preload_fetch_addr(keyfile);
if (data == NULL) {
G_ELI_DEBUG(0, "Cannot find key file data for %s.",
name);
return (0);
}
size = preload_fetch_size(keyfile);
if (size == 0) {
G_ELI_DEBUG(0, "Cannot find key file size for %s.",
name);
return (0);
}
file = preload_search_info(keyfile, MODINFO_NAME);
if (file == NULL) {
G_ELI_DEBUG(0, "Cannot find key file name for %s.",
name);
return (0);
}
G_ELI_DEBUG(1, "Loaded keyfile %s for %s (type: %s).", file,
provider, name);
g_eli_crypto_hmac_update(ctx, data, size);
}
}
static void
g_eli_keyfiles_clear(const char *provider)
{
u_char *keyfile, *data;
char name[64];
size_t size;
int i;
for (i = 0; ; i++) {
snprintf(name, sizeof(name), "%s:geli_keyfile%d", provider, i);
keyfile = preload_search_by_type(name);
if (keyfile == NULL)
return;
data = preload_fetch_addr(keyfile);
size = preload_fetch_size(keyfile);
if (data != NULL && size != 0)
bzero(data, size);
}
}
/*
* Tasting is only made on boot.
* We detect providers which should be attached before root is mounted.
*/
static struct g_geom *
g_eli_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
{
struct g_eli_metadata md;
struct g_geom *gp;
struct hmac_ctx ctx;
char passphrase[256];
u_char key[G_ELI_USERKEYLEN], mkey[G_ELI_DATAIVKEYLEN];
u_int i, nkey, nkeyfiles, tries;
int error;
struct keybuf *keybuf;
g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
g_topology_assert();
if (root_mounted() || g_eli_tries == 0)
return (NULL);
G_ELI_DEBUG(3, "Tasting %s.", pp->name);
error = g_eli_read_metadata(mp, pp, &md);
if (error != 0)
return (NULL);
gp = NULL;
if (strcmp(md.md_magic, G_ELI_MAGIC) != 0)
return (NULL);
if (md.md_version > G_ELI_VERSION) {
printf("geom_eli.ko module is too old to handle %s.\n",
pp->name);
return (NULL);
}
if (md.md_provsize != pp->mediasize)
return (NULL);
/* Should we attach it on boot? */
if (!(md.md_flags & G_ELI_FLAG_BOOT))
return (NULL);
if (md.md_keys == 0x00) {
G_ELI_DEBUG(0, "No valid keys on %s.", pp->name);
return (NULL);
}
if (md.md_iterations == -1) {
/* If there is no passphrase, we try only once. */
tries = 1;
} else {
/* Ask for the passphrase no more than g_eli_tries times. */
tries = g_eli_tries;
}
if ((keybuf = get_keybuf()) != NULL) {
/* Scan the key buffer, try all GELI keys. */
for (i = 0; i < keybuf->kb_nents; i++) {
if (keybuf->kb_ents[i].ke_type == KEYBUF_TYPE_GELI) {
memcpy(key, keybuf->kb_ents[i].ke_data,
sizeof(key));
if (g_eli_mkey_decrypt(&md, key,
mkey, &nkey) == 0 ) {
explicit_bzero(key, sizeof(key));
goto have_key;
}
}
}
}
for (i = 0; i <= tries; i++) {
g_eli_crypto_hmac_init(&ctx, NULL, 0);
/*
* Load all key files.
*/
nkeyfiles = g_eli_keyfiles_load(&ctx, pp->name);
if (nkeyfiles == 0 && md.md_iterations == -1) {
/*
* No key files and no passphrase, something is
* definitely wrong here.
* geli(8) doesn't allow for such situation, so assume
* that there was really no passphrase and in that case
* key files are no properly defined in loader.conf.
*/
G_ELI_DEBUG(0,
"Found no key files in loader.conf for %s.",
pp->name);
return (NULL);
}
/* Ask for the passphrase if defined. */
if (md.md_iterations >= 0) {
/* Try first with cached passphrase. */
if (i == 0) {
if (!g_eli_boot_passcache)
continue;
memcpy(passphrase, cached_passphrase,
sizeof(passphrase));
} else {
printf("Enter passphrase for %s: ", pp->name);
cngets(passphrase, sizeof(passphrase),
g_eli_visible_passphrase);
memcpy(cached_passphrase, passphrase,
sizeof(passphrase));
}
}
/*
* Prepare Derived-Key from the user passphrase.
*/
if (md.md_iterations == 0) {
g_eli_crypto_hmac_update(&ctx, md.md_salt,
sizeof(md.md_salt));
g_eli_crypto_hmac_update(&ctx, passphrase,
strlen(passphrase));
explicit_bzero(passphrase, sizeof(passphrase));
} else if (md.md_iterations > 0) {
u_char dkey[G_ELI_USERKEYLEN];
pkcs5v2_genkey(dkey, sizeof(dkey), md.md_salt,
sizeof(md.md_salt), passphrase, md.md_iterations);
bzero(passphrase, sizeof(passphrase));
g_eli_crypto_hmac_update(&ctx, dkey, sizeof(dkey));
explicit_bzero(dkey, sizeof(dkey));
}
g_eli_crypto_hmac_final(&ctx, key, 0);
/*
* Decrypt Master-Key.
*/
error = g_eli_mkey_decrypt(&md, key, mkey, &nkey);
bzero(key, sizeof(key));
if (error == -1) {
if (i == tries) {
G_ELI_DEBUG(0,
"Wrong key for %s. No tries left.",
pp->name);
g_eli_keyfiles_clear(pp->name);
return (NULL);
}
if (i > 0) {
G_ELI_DEBUG(0,
"Wrong key for %s. Tries left: %u.",
pp->name, tries - i);
}
/* Try again. */
continue;
} else if (error > 0) {
G_ELI_DEBUG(0,
"Cannot decrypt Master Key for %s (error=%d).",
pp->name, error);
g_eli_keyfiles_clear(pp->name);
return (NULL);
}
g_eli_keyfiles_clear(pp->name);
G_ELI_DEBUG(1, "Using Master Key %u for %s.", nkey, pp->name);
break;
}
have_key:
/*
* We have correct key, let's attach provider.
*/
gp = g_eli_create(NULL, mp, pp, &md, mkey, nkey);
bzero(mkey, sizeof(mkey));
bzero(&md, sizeof(md));
if (gp == NULL) {
G_ELI_DEBUG(0, "Cannot create device %s%s.", pp->name,
G_ELI_SUFFIX);
return (NULL);
}
return (gp);
}
static void
g_eli_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
struct g_consumer *cp, struct g_provider *pp)
{
struct g_eli_softc *sc;
g_topology_assert();
sc = gp->softc;
if (sc == NULL)
return;
if (pp != NULL || cp != NULL)
return; /* Nothing here. */
sbuf_printf(sb, "%s<KeysTotal>%ju</KeysTotal>\n", indent,
(uintmax_t)sc->sc_ekeys_total);
sbuf_printf(sb, "%s<KeysAllocated>%ju</KeysAllocated>\n", indent,
(uintmax_t)sc->sc_ekeys_allocated);
sbuf_printf(sb, "%s<Flags>", indent);
if (sc->sc_flags == 0)
sbuf_printf(sb, "NONE");
else {
int first = 1;
#define ADD_FLAG(flag, name) do { \
if (sc->sc_flags & (flag)) { \
if (!first) \
sbuf_printf(sb, ", "); \
else \
first = 0; \
sbuf_printf(sb, name); \
} \
} while (0)
ADD_FLAG(G_ELI_FLAG_SUSPEND, "SUSPEND");
ADD_FLAG(G_ELI_FLAG_SINGLE_KEY, "SINGLE-KEY");
ADD_FLAG(G_ELI_FLAG_NATIVE_BYTE_ORDER, "NATIVE-BYTE-ORDER");
ADD_FLAG(G_ELI_FLAG_ONETIME, "ONETIME");
ADD_FLAG(G_ELI_FLAG_BOOT, "BOOT");
ADD_FLAG(G_ELI_FLAG_WO_DETACH, "W-DETACH");
ADD_FLAG(G_ELI_FLAG_RW_DETACH, "RW-DETACH");
ADD_FLAG(G_ELI_FLAG_AUTH, "AUTH");
ADD_FLAG(G_ELI_FLAG_WOPEN, "W-OPEN");
ADD_FLAG(G_ELI_FLAG_DESTROY, "DESTROY");
ADD_FLAG(G_ELI_FLAG_RO, "READ-ONLY");
ADD_FLAG(G_ELI_FLAG_NODELETE, "NODELETE");
ADD_FLAG(G_ELI_FLAG_GELIBOOT, "GELIBOOT");
#undef ADD_FLAG
}
sbuf_printf(sb, "</Flags>\n");
if (!(sc->sc_flags & G_ELI_FLAG_ONETIME)) {
sbuf_printf(sb, "%s<UsedKey>%u</UsedKey>\n", indent,
sc->sc_nkey);
}
sbuf_printf(sb, "%s<Version>%u</Version>\n", indent, sc->sc_version);
sbuf_printf(sb, "%s<Crypto>", indent);
switch (sc->sc_crypto) {
case G_ELI_CRYPTO_HW:
sbuf_printf(sb, "hardware");
break;
case G_ELI_CRYPTO_SW:
sbuf_printf(sb, "software");
break;
default:
sbuf_printf(sb, "UNKNOWN");
break;
}
sbuf_printf(sb, "</Crypto>\n");
if (sc->sc_flags & G_ELI_FLAG_AUTH) {
sbuf_printf(sb,
"%s<AuthenticationAlgorithm>%s</AuthenticationAlgorithm>\n",
indent, g_eli_algo2str(sc->sc_aalgo));
}
sbuf_printf(sb, "%s<KeyLength>%u</KeyLength>\n", indent,
sc->sc_ekeylen);
sbuf_printf(sb, "%s<EncryptionAlgorithm>%s</EncryptionAlgorithm>\n",
indent, g_eli_algo2str(sc->sc_ealgo));
sbuf_printf(sb, "%s<State>%s</State>\n", indent,
(sc->sc_flags & G_ELI_FLAG_SUSPEND) ? "SUSPENDED" : "ACTIVE");
}
static void
g_eli_shutdown_pre_sync(void *arg, int howto)
{
struct g_class *mp;
struct g_geom *gp, *gp2;
struct g_provider *pp;
struct g_eli_softc *sc;
int error;
mp = arg;
g_topology_lock();
LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
sc = gp->softc;
if (sc == NULL)
continue;
pp = LIST_FIRST(&gp->provider);
KASSERT(pp != NULL, ("No provider? gp=%p (%s)", gp, gp->name));
if (pp->acr + pp->acw + pp->ace == 0)
error = g_eli_destroy(sc, TRUE);
else {
sc->sc_flags |= G_ELI_FLAG_RW_DETACH;
gp->access = g_eli_access;
}
}
g_topology_unlock();
}
static void
g_eli_init(struct g_class *mp)
{
g_eli_pre_sync = EVENTHANDLER_REGISTER(shutdown_pre_sync,
g_eli_shutdown_pre_sync, mp, SHUTDOWN_PRI_FIRST);
if (g_eli_pre_sync == NULL)
G_ELI_DEBUG(0, "Warning! Cannot register shutdown event.");
}
static void
g_eli_fini(struct g_class *mp)
{
if (g_eli_pre_sync != NULL)
EVENTHANDLER_DEREGISTER(shutdown_pre_sync, g_eli_pre_sync);
}
DECLARE_GEOM_CLASS(g_eli_class, g_eli);
MODULE_DEPEND(g_eli, crypto, 1, 1, 1);
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