2 * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
32 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 #include <sys/sysctl.h>
35 #include <sys/systm.h>
37 #include <sys/queue.h>
40 #include <geom/geom.h>
42 #include <geom/eli/g_eli.h>
45 MALLOC_DECLARE(M_ELI);
47 SYSCTL_DECL(_kern_geom_eli);
49 * The default limit (8192 keys) will allow to cache all keys for 4TB
50 * provider with 512 bytes sectors and will take around 1MB of memory.
52 static u_int g_eli_key_cache_limit = 8192;
53 SYSCTL_UINT(_kern_geom_eli, OID_AUTO, key_cache_limit, CTLFLAG_RDTUN,
54 &g_eli_key_cache_limit, 0, "Maximum number of encryption keys to cache");
55 static uint64_t g_eli_key_cache_hits;
56 SYSCTL_UQUAD(_kern_geom_eli, OID_AUTO, key_cache_hits, CTLFLAG_RW,
57 &g_eli_key_cache_hits, 0, "Key cache hits");
58 static uint64_t g_eli_key_cache_misses;
59 SYSCTL_UQUAD(_kern_geom_eli, OID_AUTO, key_cache_misses, CTLFLAG_RW,
60 &g_eli_key_cache_misses, 0, "Key cache misses");
65 g_eli_key_cmp(const struct g_eli_key *a, const struct g_eli_key *b)
68 if (a->gek_keyno > b->gek_keyno)
70 else if (a->gek_keyno < b->gek_keyno)
76 g_eli_key_fill(struct g_eli_softc *sc, struct g_eli_key *key, uint64_t keyno)
84 if ((sc->sc_flags & G_ELI_FLAG_ENC_IVKEY) != 0)
89 bcopy("ekey", hmacdata.magic, 4);
90 le64enc(hmacdata.keyno, keyno);
91 g_eli_crypto_hmac(ekey, G_ELI_MAXKEYLEN, (uint8_t *)&hmacdata,
92 sizeof(hmacdata), key->gek_key, 0);
93 key->gek_keyno = keyno;
95 key->gek_magic = G_ELI_KEY_MAGIC;
99 RB_PROTOTYPE(g_eli_key_tree, g_eli_key, gek_link, g_eli_key_cmp);
100 RB_GENERATE(g_eli_key_tree, g_eli_key, gek_link, g_eli_key_cmp);
102 static struct g_eli_key *
103 g_eli_key_allocate(struct g_eli_softc *sc, uint64_t keyno)
105 struct g_eli_key *key, *ekey, keysearch;
107 mtx_assert(&sc->sc_ekeys_lock, MA_OWNED);
108 mtx_unlock(&sc->sc_ekeys_lock);
110 key = malloc(sizeof(*key), M_ELI, M_WAITOK);
111 g_eli_key_fill(sc, key, keyno);
113 mtx_lock(&sc->sc_ekeys_lock);
115 * Recheck if the key wasn't added while we weren't holding the lock.
117 keysearch.gek_keyno = keyno;
118 ekey = RB_FIND(g_eli_key_tree, &sc->sc_ekeys_tree, &keysearch);
120 explicit_bzero(key, sizeof(*key));
123 TAILQ_REMOVE(&sc->sc_ekeys_queue, key, gek_next);
125 RB_INSERT(g_eli_key_tree, &sc->sc_ekeys_tree, key);
126 sc->sc_ekeys_allocated++;
128 TAILQ_INSERT_TAIL(&sc->sc_ekeys_queue, key, gek_next);
133 static struct g_eli_key *
134 g_eli_key_find_last(struct g_eli_softc *sc)
136 struct g_eli_key *key;
138 mtx_assert(&sc->sc_ekeys_lock, MA_OWNED);
140 TAILQ_FOREACH(key, &sc->sc_ekeys_queue, gek_next) {
141 if (key->gek_count == 0)
149 g_eli_key_replace(struct g_eli_softc *sc, struct g_eli_key *key, uint64_t keyno)
152 mtx_assert(&sc->sc_ekeys_lock, MA_OWNED);
153 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC, ("Invalid magic."));
155 RB_REMOVE(g_eli_key_tree, &sc->sc_ekeys_tree, key);
156 TAILQ_REMOVE(&sc->sc_ekeys_queue, key, gek_next);
158 KASSERT(key->gek_count == 0, ("gek_count=%d", key->gek_count));
160 g_eli_key_fill(sc, key, keyno);
162 RB_INSERT(g_eli_key_tree, &sc->sc_ekeys_tree, key);
163 TAILQ_INSERT_TAIL(&sc->sc_ekeys_queue, key, gek_next);
167 g_eli_key_remove(struct g_eli_softc *sc, struct g_eli_key *key)
170 mtx_assert(&sc->sc_ekeys_lock, MA_OWNED);
171 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC, ("Invalid magic."));
172 KASSERT(key->gek_count == 0, ("gek_count=%d", key->gek_count));
174 RB_REMOVE(g_eli_key_tree, &sc->sc_ekeys_tree, key);
175 TAILQ_REMOVE(&sc->sc_ekeys_queue, key, gek_next);
176 sc->sc_ekeys_allocated--;
177 explicit_bzero(key, sizeof(*key));
182 g_eli_key_init(struct g_eli_softc *sc)
186 mtx_lock(&sc->sc_ekeys_lock);
188 mkey = sc->sc_mkey + sizeof(sc->sc_ivkey);
189 if ((sc->sc_flags & G_ELI_FLAG_AUTH) == 0)
190 bcopy(mkey, sc->sc_ekey, G_ELI_DATAKEYLEN);
193 * The encryption key is: ekey = HMAC_SHA512(Data-Key, 0x10)
195 g_eli_crypto_hmac(mkey, G_ELI_MAXKEYLEN, "\x10", 1,
199 if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) != 0) {
200 sc->sc_ekeys_total = 1;
201 sc->sc_ekeys_allocated = 0;
206 if ((sc->sc_flags & G_ELI_FLAG_AUTH) != 0) {
207 struct g_provider *pp;
209 pp = LIST_FIRST(&sc->sc_geom->consumer)->provider;
210 mediasize = pp->mediasize;
211 blocksize = pp->sectorsize;
213 mediasize = sc->sc_mediasize;
214 blocksize = sc->sc_sectorsize;
217 ((mediasize - 1) >> G_ELI_KEY_SHIFT) / blocksize + 1;
218 sc->sc_ekeys_allocated = 0;
219 TAILQ_INIT(&sc->sc_ekeys_queue);
220 RB_INIT(&sc->sc_ekeys_tree);
221 if (sc->sc_ekeys_total <= g_eli_key_cache_limit) {
224 for (keyno = 0; keyno < sc->sc_ekeys_total; keyno++)
225 (void)g_eli_key_allocate(sc, keyno);
226 KASSERT(sc->sc_ekeys_total == sc->sc_ekeys_allocated,
227 ("sc_ekeys_total=%ju != sc_ekeys_allocated=%ju",
228 (uintmax_t)sc->sc_ekeys_total,
229 (uintmax_t)sc->sc_ekeys_allocated));
233 mtx_unlock(&sc->sc_ekeys_lock);
237 g_eli_key_destroy(struct g_eli_softc *sc)
240 mtx_lock(&sc->sc_ekeys_lock);
241 if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) != 0) {
242 explicit_bzero(sc->sc_ekey, sizeof(sc->sc_ekey));
244 struct g_eli_key *key;
246 while ((key = TAILQ_FIRST(&sc->sc_ekeys_queue)) != NULL)
247 g_eli_key_remove(sc, key);
248 TAILQ_INIT(&sc->sc_ekeys_queue);
249 RB_INIT(&sc->sc_ekeys_tree);
251 mtx_unlock(&sc->sc_ekeys_lock);
255 * Select encryption key. If G_ELI_FLAG_SINGLE_KEY is present we only have one
256 * key available for all the data. If the flag is not present select the key
257 * based on data offset.
260 g_eli_key_hold(struct g_eli_softc *sc, off_t offset, size_t blocksize)
262 struct g_eli_key *key, keysearch;
265 if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) != 0)
266 return (sc->sc_ekey);
268 /* We switch key every 2^G_ELI_KEY_SHIFT blocks. */
269 keyno = (offset >> G_ELI_KEY_SHIFT) / blocksize;
271 KASSERT(keyno < sc->sc_ekeys_total,
272 ("%s: keyno=%ju >= sc_ekeys_total=%ju",
273 __func__, (uintmax_t)keyno, (uintmax_t)sc->sc_ekeys_total));
275 keysearch.gek_keyno = keyno;
277 if (sc->sc_ekeys_total == sc->sc_ekeys_allocated) {
278 /* We have all the keys, so avoid some overhead. */
279 key = RB_FIND(g_eli_key_tree, &sc->sc_ekeys_tree, &keysearch);
280 KASSERT(key != NULL, ("No key %ju found.", (uintmax_t)keyno));
281 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC,
282 ("Invalid key magic."));
283 return (key->gek_key);
286 mtx_lock(&sc->sc_ekeys_lock);
287 key = RB_FIND(g_eli_key_tree, &sc->sc_ekeys_tree, &keysearch);
289 g_eli_key_cache_hits++;
290 TAILQ_REMOVE(&sc->sc_ekeys_queue, key, gek_next);
291 TAILQ_INSERT_TAIL(&sc->sc_ekeys_queue, key, gek_next);
294 * No key in cache, find the least recently unreferenced key
295 * or allocate one if we haven't reached our limit yet.
297 if (sc->sc_ekeys_allocated < g_eli_key_cache_limit) {
298 key = g_eli_key_allocate(sc, keyno);
300 g_eli_key_cache_misses++;
301 key = g_eli_key_find_last(sc);
303 g_eli_key_replace(sc, key, keyno);
305 /* All keys are referenced? Allocate one. */
306 key = g_eli_key_allocate(sc, keyno);
311 mtx_unlock(&sc->sc_ekeys_lock);
313 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC, ("Invalid key magic."));
315 return (key->gek_key);
319 g_eli_key_drop(struct g_eli_softc *sc, uint8_t *rawkey)
321 struct g_eli_key *key = (struct g_eli_key *)rawkey;
323 if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) != 0)
326 KASSERT(key->gek_magic == G_ELI_KEY_MAGIC, ("Invalid key magic."));
328 if (sc->sc_ekeys_total == sc->sc_ekeys_allocated)
331 mtx_lock(&sc->sc_ekeys_lock);
332 KASSERT(key->gek_count > 0, ("key->gek_count=%d", key->gek_count));
334 while (sc->sc_ekeys_allocated > g_eli_key_cache_limit) {
335 key = g_eli_key_find_last(sc);
338 g_eli_key_remove(sc, key);
340 mtx_unlock(&sc->sc_ekeys_lock);