freebsd-skq/sys/opencrypto/cryptodev.c
pjd 1a4683ef59 Fix bogus check. It was possible to panic the kernel by giving 0 length.
This is actually a local DoS, as every user can use /dev/crypto if there
is crypto hardware in the system and cryptodev.ko is loaded (or compiled
into the kernel).

Reported by:	Mike Tancsa <mike@sentex.net>
MFC after:	1 day
2005-08-18 11:58:03 +00:00

823 lines
18 KiB
C

/* $OpenBSD: cryptodev.c,v 1.52 2002/06/19 07:22:46 deraadt Exp $ */
/*-
* Copyright (c) 2001 Theo de Raadt
*
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* Effort sponsored in part by the Defense Advanced Research Projects
* Agency (DARPA) and Air Force Research Laboratory, Air Force
* Materiel Command, USAF, under agreement number F30602-01-2-0537.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/errno.h>
#include <sys/uio.h>
#include <sys/random.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/fcntl.h>
#include <opencrypto/cryptodev.h>
#include <opencrypto/xform.h>
struct csession {
TAILQ_ENTRY(csession) next;
u_int64_t sid;
u_int32_t ses;
struct mtx lock; /* for op submission */
u_int32_t cipher;
struct enc_xform *txform;
u_int32_t mac;
struct auth_hash *thash;
caddr_t key;
int keylen;
u_char tmp_iv[EALG_MAX_BLOCK_LEN];
caddr_t mackey;
int mackeylen;
u_char tmp_mac[CRYPTO_MAX_MAC_LEN];
struct iovec iovec;
struct uio uio;
int error;
};
struct fcrypt {
TAILQ_HEAD(csessionlist, csession) csessions;
int sesn;
};
static int cryptof_rw(struct file *fp, struct uio *uio,
struct ucred *cred, int flags, struct thread *);
static int cryptof_ioctl(struct file *, u_long, void *,
struct ucred *, struct thread *);
static int cryptof_poll(struct file *, int, struct ucred *, struct thread *);
static int cryptof_kqfilter(struct file *, struct knote *);
static int cryptof_stat(struct file *, struct stat *,
struct ucred *, struct thread *);
static int cryptof_close(struct file *, struct thread *);
static struct fileops cryptofops = {
.fo_read = cryptof_rw,
.fo_write = cryptof_rw,
.fo_ioctl = cryptof_ioctl,
.fo_poll = cryptof_poll,
.fo_kqfilter = cryptof_kqfilter,
.fo_stat = cryptof_stat,
.fo_close = cryptof_close
};
static struct csession *csefind(struct fcrypt *, u_int);
static int csedelete(struct fcrypt *, struct csession *);
static struct csession *cseadd(struct fcrypt *, struct csession *);
static struct csession *csecreate(struct fcrypt *, u_int64_t, caddr_t,
u_int64_t, caddr_t, u_int64_t, u_int32_t, u_int32_t, struct enc_xform *,
struct auth_hash *);
static int csefree(struct csession *);
static int cryptodev_op(struct csession *, struct crypt_op *,
struct ucred *, struct thread *td);
static int cryptodev_key(struct crypt_kop *);
static int
cryptof_rw(
struct file *fp,
struct uio *uio,
struct ucred *active_cred,
int flags,
struct thread *td)
{
return (EIO);
}
/* ARGSUSED */
static int
cryptof_ioctl(
struct file *fp,
u_long cmd,
void *data,
struct ucred *active_cred,
struct thread *td)
{
struct cryptoini cria, crie;
struct fcrypt *fcr = fp->f_data;
struct csession *cse;
struct session_op *sop;
struct crypt_op *cop;
struct enc_xform *txform = NULL;
struct auth_hash *thash = NULL;
u_int64_t sid;
u_int32_t ses;
int error = 0;
/*
* XXX: Not sure Giant is needed, but better safe than sorry
*/
mtx_lock(&Giant);
switch (cmd) {
case CIOCGSESSION:
sop = (struct session_op *)data;
switch (sop->cipher) {
case 0:
break;
case CRYPTO_DES_CBC:
txform = &enc_xform_des;
break;
case CRYPTO_3DES_CBC:
txform = &enc_xform_3des;
break;
case CRYPTO_BLF_CBC:
txform = &enc_xform_blf;
break;
case CRYPTO_CAST_CBC:
txform = &enc_xform_cast5;
break;
case CRYPTO_SKIPJACK_CBC:
txform = &enc_xform_skipjack;
break;
case CRYPTO_AES_CBC:
txform = &enc_xform_rijndael128;
break;
case CRYPTO_NULL_CBC:
txform = &enc_xform_null;
break;
case CRYPTO_ARC4:
txform = &enc_xform_arc4;
break;
default:
mtx_unlock(&Giant);
return (EINVAL);
}
switch (sop->mac) {
case 0:
break;
case CRYPTO_MD5_HMAC:
thash = &auth_hash_hmac_md5_96;
break;
case CRYPTO_SHA1_HMAC:
thash = &auth_hash_hmac_sha1_96;
break;
case CRYPTO_SHA2_HMAC:
if (sop->mackeylen == auth_hash_hmac_sha2_256.keysize)
thash = &auth_hash_hmac_sha2_256;
else if (sop->mackeylen == auth_hash_hmac_sha2_384.keysize)
thash = &auth_hash_hmac_sha2_384;
else if (sop->mackeylen == auth_hash_hmac_sha2_512.keysize)
thash = &auth_hash_hmac_sha2_512;
else {
mtx_unlock(&Giant);
return (EINVAL);
}
break;
case CRYPTO_RIPEMD160_HMAC:
thash = &auth_hash_hmac_ripemd_160_96;
break;
#ifdef notdef
case CRYPTO_MD5:
thash = &auth_hash_md5;
break;
case CRYPTO_SHA1:
thash = &auth_hash_sha1;
break;
#endif
case CRYPTO_NULL_HMAC:
thash = &auth_hash_null;
break;
default:
mtx_unlock(&Giant);
return (EINVAL);
}
bzero(&crie, sizeof(crie));
bzero(&cria, sizeof(cria));
if (txform) {
crie.cri_alg = txform->type;
crie.cri_klen = sop->keylen * 8;
if (sop->keylen > txform->maxkey ||
sop->keylen < txform->minkey) {
error = EINVAL;
goto bail;
}
MALLOC(crie.cri_key, u_int8_t *,
crie.cri_klen / 8, M_XDATA, M_WAITOK);
if ((error = copyin(sop->key, crie.cri_key,
crie.cri_klen / 8)))
goto bail;
if (thash)
crie.cri_next = &cria;
}
if (thash) {
cria.cri_alg = thash->type;
cria.cri_klen = sop->mackeylen * 8;
if (sop->mackeylen != thash->keysize) {
error = EINVAL;
goto bail;
}
if (cria.cri_klen) {
MALLOC(cria.cri_key, u_int8_t *,
cria.cri_klen / 8, M_XDATA, M_WAITOK);
if ((error = copyin(sop->mackey, cria.cri_key,
cria.cri_klen / 8)))
goto bail;
}
}
error = crypto_newsession(&sid, (txform ? &crie : &cria), 1);
if (error)
goto bail;
cse = csecreate(fcr, sid, crie.cri_key, crie.cri_klen,
cria.cri_key, cria.cri_klen, sop->cipher, sop->mac, txform,
thash);
if (cse == NULL) {
crypto_freesession(sid);
error = EINVAL;
goto bail;
}
sop->ses = cse->ses;
bail:
if (error) {
if (crie.cri_key)
FREE(crie.cri_key, M_XDATA);
if (cria.cri_key)
FREE(cria.cri_key, M_XDATA);
}
break;
case CIOCFSESSION:
ses = *(u_int32_t *)data;
cse = csefind(fcr, ses);
if (cse == NULL) {
mtx_unlock(&Giant);
return (EINVAL);
}
csedelete(fcr, cse);
error = csefree(cse);
break;
case CIOCCRYPT:
cop = (struct crypt_op *)data;
cse = csefind(fcr, cop->ses);
if (cse == NULL) {
mtx_unlock(&Giant);
return (EINVAL);
}
error = cryptodev_op(cse, cop, active_cred, td);
break;
case CIOCKEY:
error = cryptodev_key((struct crypt_kop *)data);
break;
case CIOCASYMFEAT:
error = crypto_getfeat((int *)data);
break;
default:
error = EINVAL;
}
mtx_unlock(&Giant);
return (error);
}
static int cryptodev_cb(void *);
static int
cryptodev_op(
struct csession *cse,
struct crypt_op *cop,
struct ucred *active_cred,
struct thread *td)
{
struct cryptop *crp = NULL;
struct cryptodesc *crde = NULL, *crda = NULL;
int error;
if (cop->len > 256*1024-4)
return (E2BIG);
if (cse->txform) {
if (cop->len == 0 || (cop->len % cse->txform->blocksize) != 0)
return (EINVAL);
}
cse->uio.uio_iov = &cse->iovec;
cse->uio.uio_iovcnt = 1;
cse->uio.uio_offset = 0;
cse->uio.uio_resid = cop->len;
cse->uio.uio_segflg = UIO_SYSSPACE;
cse->uio.uio_rw = UIO_WRITE;
cse->uio.uio_td = td;
cse->uio.uio_iov[0].iov_len = cop->len;
cse->uio.uio_iov[0].iov_base = malloc(cop->len, M_XDATA, M_WAITOK);
crp = crypto_getreq((cse->txform != NULL) + (cse->thash != NULL));
if (crp == NULL) {
error = ENOMEM;
goto bail;
}
if (cse->thash) {
crda = crp->crp_desc;
if (cse->txform)
crde = crda->crd_next;
} else {
if (cse->txform)
crde = crp->crp_desc;
else {
error = EINVAL;
goto bail;
}
}
if ((error = copyin(cop->src, cse->uio.uio_iov[0].iov_base, cop->len)))
goto bail;
if (crda) {
crda->crd_skip = 0;
crda->crd_len = cop->len;
crda->crd_inject = 0; /* ??? */
crda->crd_alg = cse->mac;
crda->crd_key = cse->mackey;
crda->crd_klen = cse->mackeylen * 8;
}
if (crde) {
if (cop->op == COP_ENCRYPT)
crde->crd_flags |= CRD_F_ENCRYPT;
else
crde->crd_flags &= ~CRD_F_ENCRYPT;
crde->crd_len = cop->len;
crde->crd_inject = 0;
crde->crd_alg = cse->cipher;
crde->crd_key = cse->key;
crde->crd_klen = cse->keylen * 8;
}
crp->crp_ilen = cop->len;
crp->crp_flags = CRYPTO_F_IOV | CRYPTO_F_CBIMM
| (cop->flags & COP_F_BATCH);
crp->crp_buf = (caddr_t)&cse->uio;
crp->crp_callback = (int (*) (struct cryptop *)) cryptodev_cb;
crp->crp_sid = cse->sid;
crp->crp_opaque = (void *)cse;
if (cop->iv) {
if (crde == NULL) {
error = EINVAL;
goto bail;
}
if (cse->cipher == CRYPTO_ARC4) { /* XXX use flag? */
error = EINVAL;
goto bail;
}
if ((error = copyin(cop->iv, cse->tmp_iv, cse->txform->blocksize)))
goto bail;
bcopy(cse->tmp_iv, crde->crd_iv, cse->txform->blocksize);
crde->crd_flags |= CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
crde->crd_skip = 0;
} else if (cse->cipher == CRYPTO_ARC4) { /* XXX use flag? */
crde->crd_skip = 0;
} else if (crde) {
crde->crd_flags |= CRD_F_IV_PRESENT;
crde->crd_skip = cse->txform->blocksize;
crde->crd_len -= cse->txform->blocksize;
}
if (cop->mac) {
if (crda == NULL) {
error = EINVAL;
goto bail;
}
crp->crp_mac=cse->tmp_mac;
}
/*
* Let the dispatch run unlocked, then, interlock against the
* callback before checking if the operation completed and going
* to sleep. This insures drivers don't inherit our lock which
* results in a lock order reversal between crypto_dispatch forced
* entry and the crypto_done callback into us.
*/
error = crypto_dispatch(crp);
mtx_lock(&cse->lock);
if (error == 0 && (crp->crp_flags & CRYPTO_F_DONE) == 0)
error = msleep(crp, &cse->lock, PWAIT, "crydev", 0);
mtx_unlock(&cse->lock);
if (error != 0)
goto bail;
if (crp->crp_etype != 0) {
error = crp->crp_etype;
goto bail;
}
if (cse->error) {
error = cse->error;
goto bail;
}
if (cop->dst &&
(error = copyout(cse->uio.uio_iov[0].iov_base, cop->dst, cop->len)))
goto bail;
if (cop->mac &&
(error = copyout(crp->crp_mac, cop->mac, cse->thash->authsize)))
goto bail;
bail:
if (crp)
crypto_freereq(crp);
if (cse->uio.uio_iov[0].iov_base)
free(cse->uio.uio_iov[0].iov_base, M_XDATA);
return (error);
}
static int
cryptodev_cb(void *op)
{
struct cryptop *crp = (struct cryptop *) op;
struct csession *cse = (struct csession *)crp->crp_opaque;
cse->error = crp->crp_etype;
if (crp->crp_etype == EAGAIN)
return crypto_dispatch(crp);
mtx_lock(&cse->lock);
wakeup_one(crp);
mtx_unlock(&cse->lock);
return (0);
}
static int
cryptodevkey_cb(void *op)
{
struct cryptkop *krp = (struct cryptkop *) op;
wakeup(krp);
return (0);
}
static int
cryptodev_key(struct crypt_kop *kop)
{
struct cryptkop *krp = NULL;
int error = EINVAL;
int in, out, size, i;
if (kop->crk_iparams + kop->crk_oparams > CRK_MAXPARAM) {
return (EFBIG);
}
in = kop->crk_iparams;
out = kop->crk_oparams;
switch (kop->crk_op) {
case CRK_MOD_EXP:
if (in == 3 && out == 1)
break;
return (EINVAL);
case CRK_MOD_EXP_CRT:
if (in == 6 && out == 1)
break;
return (EINVAL);
case CRK_DSA_SIGN:
if (in == 5 && out == 2)
break;
return (EINVAL);
case CRK_DSA_VERIFY:
if (in == 7 && out == 0)
break;
return (EINVAL);
case CRK_DH_COMPUTE_KEY:
if (in == 3 && out == 1)
break;
return (EINVAL);
default:
return (EINVAL);
}
krp = (struct cryptkop *)malloc(sizeof *krp, M_XDATA, M_WAITOK);
if (!krp)
return (ENOMEM);
bzero(krp, sizeof *krp);
krp->krp_op = kop->crk_op;
krp->krp_status = kop->crk_status;
krp->krp_iparams = kop->crk_iparams;
krp->krp_oparams = kop->crk_oparams;
krp->krp_status = 0;
krp->krp_callback = (int (*) (struct cryptkop *)) cryptodevkey_cb;
for (i = 0; i < CRK_MAXPARAM; i++)
krp->krp_param[i].crp_nbits = kop->crk_param[i].crp_nbits;
for (i = 0; i < krp->krp_iparams + krp->krp_oparams; i++) {
size = (krp->krp_param[i].crp_nbits + 7) / 8;
if (size == 0)
continue;
MALLOC(krp->krp_param[i].crp_p, caddr_t, size, M_XDATA, M_WAITOK);
if (i >= krp->krp_iparams)
continue;
error = copyin(kop->crk_param[i].crp_p, krp->krp_param[i].crp_p, size);
if (error)
goto fail;
}
error = crypto_kdispatch(krp);
if (error)
goto fail;
error = tsleep(krp, PSOCK, "crydev", 0);
if (error) {
/* XXX can this happen? if so, how do we recover? */
goto fail;
}
if (krp->krp_status != 0) {
error = krp->krp_status;
goto fail;
}
for (i = krp->krp_iparams; i < krp->krp_iparams + krp->krp_oparams; i++) {
size = (krp->krp_param[i].crp_nbits + 7) / 8;
if (size == 0)
continue;
error = copyout(krp->krp_param[i].crp_p, kop->crk_param[i].crp_p, size);
if (error)
goto fail;
}
fail:
if (krp) {
kop->crk_status = krp->krp_status;
for (i = 0; i < CRK_MAXPARAM; i++) {
if (krp->krp_param[i].crp_p)
FREE(krp->krp_param[i].crp_p, M_XDATA);
}
free(krp, M_XDATA);
}
return (error);
}
/* ARGSUSED */
static int
cryptof_poll(
struct file *fp,
int events,
struct ucred *active_cred,
struct thread *td)
{
return (0);
}
/* ARGSUSED */
static int
cryptof_kqfilter(struct file *fp, struct knote *kn)
{
return (0);
}
/* ARGSUSED */
static int
cryptof_stat(
struct file *fp,
struct stat *sb,
struct ucred *active_cred,
struct thread *td)
{
return (EOPNOTSUPP);
}
/* ARGSUSED */
static int
cryptof_close(struct file *fp, struct thread *td)
{
struct fcrypt *fcr = fp->f_data;
struct csession *cse;
while ((cse = TAILQ_FIRST(&fcr->csessions))) {
TAILQ_REMOVE(&fcr->csessions, cse, next);
(void)csefree(cse);
}
FREE(fcr, M_XDATA);
fp->f_data = NULL;
return 0;
}
static struct csession *
csefind(struct fcrypt *fcr, u_int ses)
{
struct csession *cse;
TAILQ_FOREACH(cse, &fcr->csessions, next)
if (cse->ses == ses)
return (cse);
return (NULL);
}
static int
csedelete(struct fcrypt *fcr, struct csession *cse_del)
{
struct csession *cse;
TAILQ_FOREACH(cse, &fcr->csessions, next) {
if (cse == cse_del) {
TAILQ_REMOVE(&fcr->csessions, cse, next);
return (1);
}
}
return (0);
}
static struct csession *
cseadd(struct fcrypt *fcr, struct csession *cse)
{
TAILQ_INSERT_TAIL(&fcr->csessions, cse, next);
cse->ses = fcr->sesn++;
return (cse);
}
struct csession *
csecreate(struct fcrypt *fcr, u_int64_t sid, caddr_t key, u_int64_t keylen,
caddr_t mackey, u_int64_t mackeylen, u_int32_t cipher, u_int32_t mac,
struct enc_xform *txform, struct auth_hash *thash)
{
struct csession *cse;
#ifdef INVARIANTS
/* NB: required when mtx_init is built with INVARIANTS */
MALLOC(cse, struct csession *, sizeof(struct csession),
M_XDATA, M_NOWAIT | M_ZERO);
#else
MALLOC(cse, struct csession *, sizeof(struct csession),
M_XDATA, M_NOWAIT);
#endif
if (cse == NULL)
return NULL;
mtx_init(&cse->lock, "cryptodev", "crypto session lock", MTX_DEF);
cse->key = key;
cse->keylen = keylen/8;
cse->mackey = mackey;
cse->mackeylen = mackeylen/8;
cse->sid = sid;
cse->cipher = cipher;
cse->mac = mac;
cse->txform = txform;
cse->thash = thash;
cseadd(fcr, cse);
return (cse);
}
static int
csefree(struct csession *cse)
{
int error;
error = crypto_freesession(cse->sid);
mtx_destroy(&cse->lock);
if (cse->key)
FREE(cse->key, M_XDATA);
if (cse->mackey)
FREE(cse->mackey, M_XDATA);
FREE(cse, M_XDATA);
return (error);
}
static int
cryptoopen(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
return (0);
}
static int
cryptoread(struct cdev *dev, struct uio *uio, int ioflag)
{
return (EIO);
}
static int
cryptowrite(struct cdev *dev, struct uio *uio, int ioflag)
{
return (EIO);
}
static int
cryptoioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
{
struct file *f;
struct fcrypt *fcr;
int fd, error;
switch (cmd) {
case CRIOGET:
MALLOC(fcr, struct fcrypt *,
sizeof(struct fcrypt), M_XDATA, M_WAITOK);
TAILQ_INIT(&fcr->csessions);
fcr->sesn = 0;
error = falloc(td, &f, &fd);
if (error) {
FREE(fcr, M_XDATA);
return (error);
}
/* falloc automatically provides an extra reference to 'f'. */
f->f_flag = FREAD | FWRITE;
f->f_type = DTYPE_CRYPTO;
f->f_ops = &cryptofops;
f->f_data = fcr;
*(u_int32_t *)data = fd;
fdrop(f, td);
break;
default:
error = EINVAL;
break;
}
return (error);
}
static struct cdevsw crypto_cdevsw = {
.d_version = D_VERSION,
.d_flags = D_NEEDGIANT,
.d_open = cryptoopen,
.d_read = cryptoread,
.d_write = cryptowrite,
.d_ioctl = cryptoioctl,
.d_name = "crypto",
};
static struct cdev *crypto_dev;
/*
* Initialization code, both for static and dynamic loading.
*/
static int
cryptodev_modevent(module_t mod, int type, void *unused)
{
switch (type) {
case MOD_LOAD:
if (bootverbose)
printf("crypto: <crypto device>\n");
crypto_dev = make_dev(&crypto_cdevsw, 0,
UID_ROOT, GID_WHEEL, 0666,
"crypto");
return 0;
case MOD_UNLOAD:
/*XXX disallow if active sessions */
destroy_dev(crypto_dev);
return 0;
}
return EINVAL;
}
static moduledata_t cryptodev_mod = {
"cryptodev",
cryptodev_modevent,
0
};
MODULE_VERSION(cryptodev, 1);
DECLARE_MODULE(cryptodev, cryptodev_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_DEPEND(cryptodev, crypto, 1, 1, 1);