/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright (c) 2001 Atsushi Onoe
* Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* 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.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* IEEE 802.11 generic crypto support
*/
#include <sys/types.h>
#include <sys/note.h>
#include <sys/crypto/common.h>
#include <sys/crypto/api.h>
#include <sys/strsun.h>
#include "net80211_impl.h"
extern const struct ieee80211_cipher wep;
extern const struct ieee80211_cipher tkip;
extern const struct ieee80211_cipher ccmp;
/*
* Table of registered cipher modules.
*/
static const char *cipher_modnames[] = {
"wlan_wep", /* IEEE80211_CIPHER_WEP */
"wlan_tkip", /* IEEE80211_CIPHER_TKIP */
"wlan_aes_ocb", /* IEEE80211_CIPHER_AES_OCB */
"wlan_ccmp", /* IEEE80211_CIPHER_AES_CCM */
"wlan_ckip", /* IEEE80211_CIPHER_CKIP */
};
/*
* Default "null" key management routines.
*/
/* ARGSUSED */
static int
nulldev_key_alloc(ieee80211com_t *ic, const struct ieee80211_key *k,
ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
{
*keyix = 0; /* use key index 0 for ucast key */
*rxkeyix = IEEE80211_KEYIX_NONE;
return (1);
}
/* ARGSUSED */
static int
nulldev_key_delete(ieee80211com_t *ic, const struct ieee80211_key *k)
{
return (1);
}
/* ARGSUSED */
static int
nulldev_key_set(ieee80211com_t *ic, const struct ieee80211_key *k,
const uint8_t *mac)
{
return (1);
}
/* ARGSUSED */
static void
nulldev_key_update(ieee80211com_t *ic)
{
/* noop */
}
/*
* Reset key state to an unused state. The crypto
* key allocation mechanism insures other state (e.g.
* key data) is properly setup before a key is used.
*/
void
ieee80211_crypto_resetkey(ieee80211com_t *ic,
struct ieee80211_key *k, ieee80211_keyix ix)
{
k->wk_cipher = &ieee80211_cipher_none;
k->wk_private = k->wk_cipher->ic_attach(ic, k);
k->wk_keyix = ix;
k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
}
/*
* Establish a relationship between the specified key and cipher
* and, if necessary, allocate a hardware index from the driver.
* Note that when a fixed key index is required it must be specified
* and we blindly assign it w/o consulting the driver.
*
* This must be the first call applied to a key; all the other key
* routines assume wk_cipher is setup.
*
* Locking must be handled by the caller using:
* ieee80211_key_update_begin(ic);
* ieee80211_key_update_end(ic);
*/
int
ieee80211_crypto_newkey(ieee80211com_t *ic, int cipher, int flags,
struct ieee80211_key *key)
{
const struct ieee80211_cipher *cip;
ieee80211_keyix keyix, rxkeyix;
void *keyctx;
uint16_t oflags;
/*
* Validate cipher and set reference to cipher routines.
*/
if (cipher >= IEEE80211_CIPHER_MAX) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_newkey: "
"invalid cipher %u\n", cipher);
return (0);
}
cip = ic->ic_ciphers[cipher];
/* already load all the ciphers, cip can't be NULL */
if (cip == NULL) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_newkey: "
"unable to load cipher %u, module %s\n",
cipher, cipher < IEEE80211_N(cipher_modnames) ?
cipher_modnames[cipher] : "<unknown>");
return (0);
}
oflags = key->wk_flags;
flags &= IEEE80211_KEY_COMMON;
/*
* If the hardware does not support the cipher then
* fallback to a host-based implementation.
*/
if ((ic->ic_caps & (1<<cipher)) == 0) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_newkey: "
"no h/w support for cipher %s, falling back to s/w\n",
cip->ic_name);
flags |= IEEE80211_KEY_SWCRYPT;
}
/*
* Hardware TKIP with software MIC is an important
* combination; we handle it by flagging each key,
* the cipher modules honor it.
*/
if (cipher == IEEE80211_CIPHER_TKIP &&
(ic->ic_caps & IEEE80211_C_TKIPMIC) == 0) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO,
"no h/w support for TKIP MIC, falling back to s/w\n");
flags |= IEEE80211_KEY_SWMIC;
}
/*
* Bind cipher to key instance. Note we do this
* after checking the device capabilities so the
* cipher module can optimize space usage based on
* whether or not it needs to do the cipher work.
*/
if (key->wk_cipher != cip || key->wk_flags != flags) {
again:
/*
* Fillin the flags so cipher modules can see s/w
* crypto requirements and potentially allocate
* different state and/or attach different method
* pointers.
*/
key->wk_flags = (uint16_t)flags;
keyctx = cip->ic_attach(ic, key);
if (keyctx == NULL) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO, "crypto_setkey: "
"unable to attach cipher %s\n", cip->ic_name);
key->wk_flags = oflags; /* restore old flags */
return (0);
}
CIPHER_DETACH(key); /* Detach old cipher */
key->wk_cipher = cip;
key->wk_private = keyctx;
}
/*
* Commit to requested usage so driver can see the flags.
*/
key->wk_flags = (uint16_t)flags;
/*
* Ask the driver for a key index if we don't have one.
* Note that entries in the global key table always have
* an index; this means it's safe to call this routine
* for these entries just to setup the reference to the
* cipher template. Note also that when using software
* crypto we also call the driver to give us a key index.
*/
if (key->wk_keyix == IEEE80211_KEYIX_NONE) {
if (!DEV_KEY_ALLOC(ic, key, &keyix, &rxkeyix)) {
/*
* Driver has no room; fallback to doing crypto
* in the host. We change the flags and start the
* procedure over. If we get back here then there's
* no hope and we bail. Note that this can leave
* the key in a inconsistent state if the caller
* continues to use it.
*/
if ((key->wk_flags & IEEE80211_KEY_SWCRYPT) == 0) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO,
"crypto_setkey: "
"no h/w resources for cipher %s, "
"falling back to s/w\n", cip->ic_name);
oflags = key->wk_flags;
flags |= IEEE80211_KEY_SWCRYPT;
if (cipher == IEEE80211_CIPHER_TKIP)
flags |= IEEE80211_KEY_SWMIC;
goto again;
}
ieee80211_dbg(IEEE80211_MSG_CRYPTO, "crypto_setkey: "
"unable to setup cipher %s\n", cip->ic_name);
return (0);
}
key->wk_keyix = keyix;
key->wk_rxkeyix = rxkeyix;
}
return (1);
}
/*
* Remove the key (no locking, for internal use).
*/
static int
ieee80211_crypto_delkey_locked(ieee80211com_t *ic, struct ieee80211_key *key)
{
uint16_t keyix;
ASSERT(key->wk_cipher != NULL);
keyix = key->wk_keyix;
if (keyix != IEEE80211_KEYIX_NONE) {
/*
* Remove hardware entry.
*/
if (!DEV_KEY_DELETE(ic, key)) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO,
"ieee80211_crypto_delkey_locked: ",
"driverdeletes key %u failed\n", keyix);
}
}
CIPHER_DETACH(key);
bzero(key, sizeof (struct ieee80211_key));
/* NB: cannot depend on key index to decide this */
ieee80211_crypto_resetkey(ic, key, IEEE80211_KEYIX_NONE);
return (1);
}
/*
* Remove the specified key.
*/
int
ieee80211_crypto_delkey(ieee80211com_t *ic, struct ieee80211_key *key)
{
int status;
KEY_UPDATE_BEGIN(ic);
status = ieee80211_crypto_delkey_locked(ic, key);
KEY_UPDATE_END(ic);
return (status);
}
/*
* Clear the global key table.
*/
static void
ieee80211_crypto_delglobalkeys(ieee80211com_t *ic)
{
int i;
KEY_UPDATE_BEGIN(ic);
for (i = 0; i < IEEE80211_WEP_NKID; i++)
(void) ieee80211_crypto_delkey_locked(ic, &ic->ic_nw_keys[i]);
KEY_UPDATE_END(ic);
}
/*
* Set the contents of the specified key.
*
* Locking must be handled by the caller using:
* ieee80211_key_update_begin(ic);
* ieee80211_key_update_end(ic);
*/
int
ieee80211_crypto_setkey(ieee80211com_t *ic, struct ieee80211_key *key,
const uint8_t *macaddr)
{
const struct ieee80211_cipher *cip = key->wk_cipher;
ASSERT(cip != NULL);
ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_setkey: "
"%s keyix %u flags 0x%x mac %s len %u\n",
cip->ic_name, key->wk_keyix, key->wk_flags,
ieee80211_macaddr_sprintf(macaddr), key->wk_keylen);
/*
* Give cipher a chance to validate key contents.
* should happen before modifying state.
*/
if (cip->ic_setkey(key) == 0) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_setkey: "
"cipher %s rejected key index %u len %u flags 0x%x\n",
cip->ic_name, key->wk_keyix, key->wk_keylen,
key->wk_flags);
return (0);
}
if (key->wk_keyix == IEEE80211_KEYIX_NONE) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_setkey: "
"no key index; should not happen!\n");
return (0);
}
return (DEV_KEY_SET(ic, key, macaddr));
}
/*
* Return the transmit key to use in sending a frame.
*/
struct ieee80211_key *
ieee80211_crypto_getkey(ieee80211com_t *ic)
{
if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
KEY_UNDEFINED(ic->ic_nw_keys[ic->ic_def_txkey]))
return (NULL);
return (&ic->ic_nw_keys[ic->ic_def_txkey]);
}
uint8_t
ieee80211_crypto_getciphertype(ieee80211com_t *ic)
{
struct ieee80211_key *key;
uint32_t cipher;
static const uint8_t ciphermap[] = {
WIFI_SEC_WEP, /* IEEE80211_CIPHER_WEP */
WIFI_SEC_WPA, /* IEEE80211_CIPHER_TKIP */
(uint8_t)-1, /* IEEE80211_CIPHER_AES_OCB */
WIFI_SEC_WPA, /* IEEE80211_CIPHER_AES_CCM */
(uint8_t)-1, /* IEEE80211_CIPHER_CKIP */
WIFI_SEC_NONE, /* IEEE80211_CIPHER_NONE */
};
if ((ic->ic_flags & IEEE80211_F_PRIVACY) == 0)
return (WIFI_SEC_NONE);
key = ieee80211_crypto_getkey(ic);
if (key == NULL)
return (WIFI_SEC_NONE);
cipher = key->wk_cipher->ic_cipher;
ASSERT(cipher < IEEE80211_N(ciphermap));
return (ciphermap[cipher]);
}
/*
* Add privacy headers appropriate for the specified key.
*/
struct ieee80211_key *
ieee80211_crypto_encap(ieee80211com_t *ic, mblk_t *mp)
{
struct ieee80211_key *k;
const struct ieee80211_cipher *cip;
uint8_t keyix;
if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO,
"ieee80211_crypto_encap: %s",
" No default xmit key for frame\n");
return (NULL);
}
keyix = ic->ic_def_txkey;
k = &ic->ic_nw_keys[ic->ic_def_txkey];
cip = k->wk_cipher;
return (cip->ic_encap(k, mp, keyix<<6) ? k : NULL);
}
/*
* Validate and strip privacy headers (and trailer) for a
* received frame that has the WEP/Privacy bit set.
*/
struct ieee80211_key *
ieee80211_crypto_decap(ieee80211com_t *ic, mblk_t *mp, int hdrlen)
{
struct ieee80211_key *k;
const struct ieee80211_cipher *cip;
uint8_t *ivp;
uint8_t keyid;
/* NB: this minimum size data frame could be bigger */
if (MBLKL(mp) < IEEE80211_WEP_MINLEN) {
ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_decap:"
" WEP data frame too short, len %u\n",
MBLKL(mp));
return (NULL);
}
/*
* Locate the key. If unicast and there is no unicast
* key then we fall back to the key id in the header.
* This assumes unicast keys are only configured when
* the key id in the header is meaningless (typically 0).
*/
ivp = mp->b_rptr + hdrlen;
keyid = ivp[IEEE80211_WEP_IVLEN];
k = &ic->ic_nw_keys[keyid >> 6];
/* check to avoid panic when wep is on but key is not set */
if (k->wk_cipher == &ieee80211_cipher_none ||
k->wk_cipher == NULL)
return (NULL);
cip = k->wk_cipher;
return ((cip->ic_decap)(k, mp, hdrlen) ? k : NULL);
}
/*
* Setup crypto support.
*/
void
ieee80211_crypto_attach(ieee80211com_t *ic)
{
struct ieee80211_crypto_state *cs = &ic->ic_crypto;
int i;
(void) crypto_mech2id(SUN_CKM_RC4); /* Load RC4 */
(void) crypto_mech2id(SUN_CKM_AES_CBC); /* Load AES-CBC */
(void) crypto_mech2id(SUN_CKM_AES_CCM); /* Load AES-CCM */
/* NB: we assume everything is pre-zero'd */
cs->cs_def_txkey = IEEE80211_KEYIX_NONE;
for (i = 0; i < IEEE80211_WEP_NKID; i++) {
ieee80211_crypto_resetkey(ic, &cs->cs_nw_keys[i],
IEEE80211_KEYIX_NONE);
}
/*
* Initialize the driver key support routines to noop entries.
* This is useful especially for the cipher test modules.
*/
cs->cs_key_alloc = nulldev_key_alloc;
cs->cs_key_set = nulldev_key_set;
cs->cs_key_delete = nulldev_key_delete;
cs->cs_key_update_begin = nulldev_key_update;
cs->cs_key_update_end = nulldev_key_update;
ieee80211_crypto_register(ic, &wep);
ieee80211_crypto_register(ic, &tkip);
ieee80211_crypto_register(ic, &ccmp);
}
/*
* Teardown crypto support.
*/
void
ieee80211_crypto_detach(ieee80211com_t *ic)
{
ieee80211_crypto_delglobalkeys(ic);
ieee80211_crypto_unregister(ic, &wep);
ieee80211_crypto_unregister(ic, &tkip);
ieee80211_crypto_unregister(ic, &ccmp);
}
/*
* Register a crypto cipher module.
*/
void
ieee80211_crypto_register(ieee80211com_t *ic,
const struct ieee80211_cipher *cip)
{
if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
ieee80211_err("ieee80211_crypto_register: "
"cipher %s has an invalid cipher index %u\n",
cip->ic_name, cip->ic_cipher);
return;
}
if (ic->ic_ciphers[cip->ic_cipher] != NULL &&
ic->ic_ciphers[cip->ic_cipher] != cip) {
ieee80211_err("ieee80211_crypto_register: "
"cipher %s registered with a different template\n",
cip->ic_name);
return;
}
ic->ic_ciphers[cip->ic_cipher] = cip;
}
/*
* Unregister a crypto cipher module.
*/
void
ieee80211_crypto_unregister(ieee80211com_t *ic,
const struct ieee80211_cipher *cip)
{
if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
ieee80211_err("ieee80211_crypto_unregister: "
"cipher %s has an invalid cipher index %u\n",
cip->ic_name, cip->ic_cipher);
return;
}
if (ic->ic_ciphers[cip->ic_cipher] != NULL &&
ic->ic_ciphers[cip->ic_cipher] != cip) {
ieee80211_err("ieee80211_crypto_unregister: "
"cipher %s registered with a different template\n",
cip->ic_name);
return;
}
/* NB: don't complain about not being registered */
ic->ic_ciphers[cip->ic_cipher] = NULL;
}