2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/sysctl.h>
37 #include <sys/systm.h>
39 #include <sys/queue.h>
42 #include <geom/geom.h>
44 #include <geom/eli/g_eli.h>
47 MALLOC_DECLARE(M_ELI);
49 SYSCTL_DECL(_kern_geom_eli);
51 * The default limit (8192 keys) will allow to cache all keys for 4TB
52 * provider with 512 bytes sectors and will take around 1MB of memory.
54 static u_int g_eli_key_cache_limit = 8192;
55 SYSCTL_UINT(_kern_geom_eli, OID_AUTO, key_cache_limit, CTLFLAG_RDTUN,
56 &g_eli_key_cache_limit, 0, "Maximum number of encryption keys to cache");
57 static uint64_t g_eli_key_cache_hits;
58 SYSCTL_UQUAD(_kern_geom_eli, OID_AUTO, key_cache_hits, CTLFLAG_RW,
59 &g_eli_key_cache_hits, 0, "Key cache hits");
60 static uint64_t g_eli_key_cache_misses;
61 SYSCTL_UQUAD(_kern_geom_eli, OID_AUTO, key_cache_misses, CTLFLAG_RW,
62 &g_eli_key_cache_misses, 0, "Key cache misses");
67 g_eli_key_cmp(const struct g_eli_key *a, const struct g_eli_key *b)
70 if (a->gek_keyno > b->gek_keyno)
72 else if (a->gek_keyno < b->gek_keyno)
78 g_eli_key_fill(struct g_eli_softc *sc, struct g_eli_key *key, uint64_t keyno)
86 if ((sc->sc_flags & G_ELI_FLAG_ENC_IVKEY) != 0)
91 bcopy("ekey", hmacdata.magic, 4);
92 le64enc(hmacdata.keyno, keyno);
93 g_eli_crypto_hmac(ekey, G_ELI_MAXKEYLEN, (uint8_t *)&hmacdata,
94 sizeof(hmacdata), key->gek_key, 0);
95 key->gek_keyno = keyno;
97 key->gek_magic = G_ELI_KEY_MAGIC;
101 RB_PROTOTYPE(g_eli_key_tree, g_eli_key, gek_link, g_eli_key_cmp);
102 RB_GENERATE(g_eli_key_tree, g_eli_key, gek_link, g_eli_key_cmp);
104 static struct g_eli_key *
105 g_eli_key_allocate(struct g_eli_softc *sc, uint64_t keyno)
107 struct g_eli_key *key, *ekey, keysearch;
109 mtx_assert(&sc->sc_ekeys_lock, MA_OWNED);
110 mtx_unlock(&sc->sc_ekeys_lock);
112 key = malloc(sizeof(*key), M_ELI, M_WAITOK);
113 g_eli_key_fill(sc, key, keyno);
115 mtx_lock(&sc->sc_ekeys_lock);
117 * Recheck if the key wasn't added while we weren't holding the lock.
119 keysearch.gek_keyno = keyno;
120 ekey = RB_FIND(g_eli_key_tree, &sc->sc_ekeys_tree, &keysearch);
122 explicit_bzero(key, sizeof(*key));
125 TAILQ_REMOVE(&sc->sc_ekeys_queue, key, gek_next);
127 RB_INSERT(g_eli_key_tree, &sc->sc_ekeys_tree, key);
128 sc->sc_ekeys_allocated++;
130 TAILQ_INSERT_TAIL(&sc->sc_ekeys_queue, key, gek_next);
135 static struct g_eli_key *
136 g_eli_key_find_last(struct g_eli_softc *sc)
138 struct g_eli_key *key;
140 mtx_assert(&sc->sc_ekeys_lock, MA_OWNED);
142 TAILQ_FOREACH(key, &sc->sc_ekeys_queue, gek_next) {
143 if (key->gek_count == 0)
151 g_eli_key_replace(struct g_eli_softc *sc, struct g_eli_key *key, uint64_t keyno)
154 mtx_assert(&sc->sc_ekeys_lock, MA_OWNED);
155 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC, ("Invalid magic."));
157 RB_REMOVE(g_eli_key_tree, &sc->sc_ekeys_tree, key);
158 TAILQ_REMOVE(&sc->sc_ekeys_queue, key, gek_next);
160 KASSERT(key->gek_count == 0, ("gek_count=%d", key->gek_count));
162 g_eli_key_fill(sc, key, keyno);
164 RB_INSERT(g_eli_key_tree, &sc->sc_ekeys_tree, key);
165 TAILQ_INSERT_TAIL(&sc->sc_ekeys_queue, key, gek_next);
169 g_eli_key_remove(struct g_eli_softc *sc, struct g_eli_key *key)
172 mtx_assert(&sc->sc_ekeys_lock, MA_OWNED);
173 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC, ("Invalid magic."));
174 KASSERT(key->gek_count == 0, ("gek_count=%d", key->gek_count));
176 RB_REMOVE(g_eli_key_tree, &sc->sc_ekeys_tree, key);
177 TAILQ_REMOVE(&sc->sc_ekeys_queue, key, gek_next);
178 sc->sc_ekeys_allocated--;
179 explicit_bzero(key, sizeof(*key));
184 g_eli_key_init(struct g_eli_softc *sc)
188 mtx_lock(&sc->sc_ekeys_lock);
190 mkey = sc->sc_mkey + sizeof(sc->sc_ivkey);
191 if ((sc->sc_flags & G_ELI_FLAG_AUTH) == 0)
192 bcopy(mkey, sc->sc_ekey, G_ELI_DATAKEYLEN);
195 * The encryption key is: ekey = HMAC_SHA512(Data-Key, 0x10)
197 g_eli_crypto_hmac(mkey, G_ELI_MAXKEYLEN, "\x10", 1,
201 if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) != 0) {
202 sc->sc_ekeys_total = 1;
203 sc->sc_ekeys_allocated = 0;
208 if ((sc->sc_flags & G_ELI_FLAG_AUTH) != 0) {
209 struct g_provider *pp;
211 pp = LIST_FIRST(&sc->sc_geom->consumer)->provider;
212 mediasize = pp->mediasize;
213 blocksize = pp->sectorsize;
215 mediasize = sc->sc_mediasize;
216 blocksize = sc->sc_sectorsize;
219 ((mediasize - 1) >> G_ELI_KEY_SHIFT) / blocksize + 1;
220 sc->sc_ekeys_allocated = 0;
221 TAILQ_INIT(&sc->sc_ekeys_queue);
222 RB_INIT(&sc->sc_ekeys_tree);
223 if (sc->sc_ekeys_total <= g_eli_key_cache_limit) {
226 for (keyno = 0; keyno < sc->sc_ekeys_total; keyno++)
227 (void)g_eli_key_allocate(sc, keyno);
228 KASSERT(sc->sc_ekeys_total == sc->sc_ekeys_allocated,
229 ("sc_ekeys_total=%ju != sc_ekeys_allocated=%ju",
230 (uintmax_t)sc->sc_ekeys_total,
231 (uintmax_t)sc->sc_ekeys_allocated));
235 mtx_unlock(&sc->sc_ekeys_lock);
239 g_eli_key_destroy(struct g_eli_softc *sc)
242 mtx_lock(&sc->sc_ekeys_lock);
243 if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) != 0) {
244 explicit_bzero(sc->sc_ekey, sizeof(sc->sc_ekey));
246 struct g_eli_key *key;
248 while ((key = TAILQ_FIRST(&sc->sc_ekeys_queue)) != NULL)
249 g_eli_key_remove(sc, key);
250 TAILQ_INIT(&sc->sc_ekeys_queue);
251 RB_INIT(&sc->sc_ekeys_tree);
253 mtx_unlock(&sc->sc_ekeys_lock);
257 * Select encryption key. If G_ELI_FLAG_SINGLE_KEY is present we only have one
258 * key available for all the data. If the flag is not present select the key
259 * based on data offset.
262 g_eli_key_hold(struct g_eli_softc *sc, off_t offset, size_t blocksize)
264 struct g_eli_key *key, keysearch;
267 if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) != 0)
268 return (sc->sc_ekey);
270 /* We switch key every 2^G_ELI_KEY_SHIFT blocks. */
271 keyno = (offset >> G_ELI_KEY_SHIFT) / blocksize;
273 KASSERT(keyno < sc->sc_ekeys_total,
274 ("%s: keyno=%ju >= sc_ekeys_total=%ju",
275 __func__, (uintmax_t)keyno, (uintmax_t)sc->sc_ekeys_total));
277 keysearch.gek_keyno = keyno;
279 if (sc->sc_ekeys_total == sc->sc_ekeys_allocated) {
280 /* We have all the keys, so avoid some overhead. */
281 key = RB_FIND(g_eli_key_tree, &sc->sc_ekeys_tree, &keysearch);
282 KASSERT(key != NULL, ("No key %ju found.", (uintmax_t)keyno));
283 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC,
284 ("Invalid key magic."));
285 return (key->gek_key);
288 mtx_lock(&sc->sc_ekeys_lock);
289 key = RB_FIND(g_eli_key_tree, &sc->sc_ekeys_tree, &keysearch);
291 g_eli_key_cache_hits++;
292 TAILQ_REMOVE(&sc->sc_ekeys_queue, key, gek_next);
293 TAILQ_INSERT_TAIL(&sc->sc_ekeys_queue, key, gek_next);
296 * No key in cache, find the least recently unreferenced key
297 * or allocate one if we haven't reached our limit yet.
299 if (sc->sc_ekeys_allocated < g_eli_key_cache_limit) {
300 key = g_eli_key_allocate(sc, keyno);
302 g_eli_key_cache_misses++;
303 key = g_eli_key_find_last(sc);
305 g_eli_key_replace(sc, key, keyno);
307 /* All keys are referenced? Allocate one. */
308 key = g_eli_key_allocate(sc, keyno);
313 mtx_unlock(&sc->sc_ekeys_lock);
315 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC, ("Invalid key magic."));
317 return (key->gek_key);
321 g_eli_key_drop(struct g_eli_softc *sc, uint8_t *rawkey)
323 struct g_eli_key *key = (struct g_eli_key *)rawkey;
325 if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) != 0)
328 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC, ("Invalid key magic."));
330 if (sc->sc_ekeys_total == sc->sc_ekeys_allocated)
333 mtx_lock(&sc->sc_ekeys_lock);
334 KASSERT(key->gek_count > 0, ("key->gek_count=%d", key->gek_count));
336 while (sc->sc_ekeys_allocated > g_eli_key_cache_limit) {
337 key = g_eli_key_find_last(sc);
340 g_eli_key_remove(sc, key);
342 mtx_unlock(&sc->sc_ekeys_lock);