xref: /illumos-gate/usr/src/uts/common/crypto/core/kcf_mech_tabs.c (revision cd964fce751ca752af4158842063a9579a2d4331)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/sunddi.h>
28 #include <sys/errno.h>
29 #include <sys/disp.h>
30 #include <sys/modctl.h>
31 #include <sys/modhash.h>
32 #include <sys/crypto/common.h>
33 #include <sys/crypto/api.h>
34 #include <sys/crypto/impl.h>
35 
36 /* Cryptographic mechanisms tables and their access functions */
37 
38 /*
39  * Internal numbers assigned to mechanisms are coded as follows:
40  *
41  * +----------------+----------------+
42  * | mech. class    | mech. index    |
43  * <--- 32-bits --->+<--- 32-bits --->
44  *
45  * the mech_class identifies the table the mechanism belongs to.
46  * mech_index  is the index for that mechanism in the table.
47  * A mechanism belongs to exactly 1 table.
48  * The tables are:
49  * . digest_mechs_tab[] for the msg digest mechs.
50  * . cipher_mechs_tab[] for encrypt/decrypt and wrap/unwrap mechs.
51  * . mac_mechs_tab[] for MAC mechs.
52  * . sign_mechs_tab[] for sign & verify mechs.
53  * . keyops_mechs_tab[] for key/key pair generation, and key derivation.
54  * . misc_mechs_tab[] for mechs that don't belong to any of the above.
55  *
56  * There are no holes in the tables.
57  */
58 
59 /*
60  * Locking conventions:
61  * --------------------
62  * A global mutex, kcf_mech_tabs_lock, serializes writes to the
63  * mechanism table via kcf_create_mech_entry().
64  *
65  * A mutex is associated with every entry of the tables.
66  * The mutex is acquired whenever the entry is accessed for
67  * 1) retrieving the mech_id (comparing the mech name)
68  * 2) finding a provider for an xxx_init() or atomic operation.
69  * 3) altering the mechs entry to add or remove a provider.
70  *
71  * In 2), after a provider is chosen, its prov_desc is held and the
72  * entry's mutex must be dropped. The provider's working function (SPI) is
73  * called outside the mech_entry's mutex.
74  *
75  * The number of providers for a particular mechanism is not expected to be
76  * long enough to justify the cost of using rwlocks, so the per-mechanism
77  * entry mutex won't be very *hot*.
78  *
79  * When both kcf_mech_tabs_lock and a mech_entry mutex need to be held,
80  * kcf_mech_tabs_lock must always be acquired first.
81  *
82  */
83 
84 		/* Mechanisms tables */
85 
86 
87 /* RFE 4687834 Will deal with the extensibility of these tables later */
88 
89 kcf_mech_entry_t kcf_digest_mechs_tab[KCF_MAXDIGEST];
90 kcf_mech_entry_t kcf_cipher_mechs_tab[KCF_MAXCIPHER];
91 kcf_mech_entry_t kcf_mac_mechs_tab[KCF_MAXMAC];
92 kcf_mech_entry_t kcf_sign_mechs_tab[KCF_MAXSIGN];
93 kcf_mech_entry_t kcf_keyops_mechs_tab[KCF_MAXKEYOPS];
94 kcf_mech_entry_t kcf_misc_mechs_tab[KCF_MAXMISC];
95 
96 kcf_mech_entry_tab_t kcf_mech_tabs_tab[KCF_LAST_OPSCLASS + 1] = {
97 	{0, NULL},				/* No class zero */
98 	{KCF_MAXDIGEST, kcf_digest_mechs_tab},
99 	{KCF_MAXCIPHER, kcf_cipher_mechs_tab},
100 	{KCF_MAXMAC, kcf_mac_mechs_tab},
101 	{KCF_MAXSIGN, kcf_sign_mechs_tab},
102 	{KCF_MAXKEYOPS, kcf_keyops_mechs_tab},
103 	{KCF_MAXMISC, kcf_misc_mechs_tab}
104 };
105 
106 /*
107  * Protects fields in kcf_mech_entry. This is an array
108  * of locks indexed by the cpuid. A reader needs to hold
109  * a single lock while a writer needs to hold all locks.
110  * krwlock_t is not an option here because the hold time
111  * is very small for these locks.
112  */
113 kcf_lock_withpad_t *me_mutexes;
114 
115 #define	ME_MUTEXES_ENTER_ALL()	\
116 	for (int i = 0; i < max_ncpus; i++)	\
117 		mutex_enter(&me_mutexes[i].kl_lock);
118 
119 #define	ME_MUTEXES_EXIT_ALL()	\
120 	for (int i = 0; i < max_ncpus; i++)	\
121 		mutex_exit(&me_mutexes[i].kl_lock);
122 
123 /*
124  * Per-algorithm internal thresholds for the minimum input size of before
125  * offloading to hardware provider.
126  * Dispatching a crypto operation  to a hardware provider entails paying the
127  * cost of an additional context switch.  Measurments with Sun Accelerator 4000
128  * shows that 512-byte jobs or smaller are better handled in software.
129  * There is room for refinement here.
130  *
131  */
132 int kcf_md5_threshold = 512;
133 int kcf_sha1_threshold = 512;
134 int kcf_des_threshold = 512;
135 int kcf_des3_threshold = 512;
136 int kcf_aes_threshold = 512;
137 int kcf_bf_threshold = 512;
138 int kcf_rc4_threshold = 512;
139 
140 kmutex_t kcf_mech_tabs_lock;
141 static uint32_t kcf_gen_swprov = 0;
142 
143 int kcf_mech_hash_size = 256;
144 mod_hash_t *kcf_mech_hash;	/* mech name to id hash */
145 
146 static crypto_mech_type_t
kcf_mech_hash_find(char * mechname)147 kcf_mech_hash_find(char *mechname)
148 {
149 	mod_hash_val_t hv;
150 	crypto_mech_type_t mt;
151 
152 	mt = CRYPTO_MECH_INVALID;
153 	if (mod_hash_find(kcf_mech_hash, (mod_hash_key_t)mechname, &hv) == 0) {
154 		mt = *(crypto_mech_type_t *)hv;
155 		ASSERT(mt != CRYPTO_MECH_INVALID);
156 	}
157 
158 	return (mt);
159 }
160 
161 /*
162  * kcf_init_mech_tabs()
163  *
164  * Called by the misc/kcf's _init() routine to initialize the tables
165  * of mech_entry's.
166  */
167 void
kcf_init_mech_tabs()168 kcf_init_mech_tabs()
169 {
170 	int i, max;
171 	kcf_ops_class_t class;
172 	kcf_mech_entry_t *me_tab;
173 
174 	/* Initializes the mutex locks. */
175 
176 	mutex_init(&kcf_mech_tabs_lock, NULL, MUTEX_DEFAULT, NULL);
177 
178 	/* Then the pre-defined mechanism entries */
179 
180 	/* Two digests */
181 	(void) strncpy(kcf_digest_mechs_tab[0].me_name, SUN_CKM_MD5,
182 	    CRYPTO_MAX_MECH_NAME);
183 	kcf_digest_mechs_tab[0].me_threshold = kcf_md5_threshold;
184 
185 	(void) strncpy(kcf_digest_mechs_tab[1].me_name, SUN_CKM_SHA1,
186 	    CRYPTO_MAX_MECH_NAME);
187 	kcf_digest_mechs_tab[1].me_threshold = kcf_sha1_threshold;
188 
189 	/* The symmetric ciphers in various modes */
190 	(void) strncpy(kcf_cipher_mechs_tab[0].me_name, SUN_CKM_DES_CBC,
191 	    CRYPTO_MAX_MECH_NAME);
192 	kcf_cipher_mechs_tab[0].me_threshold = kcf_des_threshold;
193 
194 	(void) strncpy(kcf_cipher_mechs_tab[1].me_name, SUN_CKM_DES3_CBC,
195 	    CRYPTO_MAX_MECH_NAME);
196 	kcf_cipher_mechs_tab[1].me_threshold = kcf_des3_threshold;
197 
198 	(void) strncpy(kcf_cipher_mechs_tab[2].me_name, SUN_CKM_DES_ECB,
199 	    CRYPTO_MAX_MECH_NAME);
200 	kcf_cipher_mechs_tab[2].me_threshold = kcf_des_threshold;
201 
202 	(void) strncpy(kcf_cipher_mechs_tab[3].me_name, SUN_CKM_DES3_ECB,
203 	    CRYPTO_MAX_MECH_NAME);
204 	kcf_cipher_mechs_tab[3].me_threshold = kcf_des3_threshold;
205 
206 	(void) strncpy(kcf_cipher_mechs_tab[4].me_name, SUN_CKM_BLOWFISH_CBC,
207 	    CRYPTO_MAX_MECH_NAME);
208 	kcf_cipher_mechs_tab[4].me_threshold = kcf_bf_threshold;
209 
210 	(void) strncpy(kcf_cipher_mechs_tab[5].me_name, SUN_CKM_BLOWFISH_ECB,
211 	    CRYPTO_MAX_MECH_NAME);
212 	kcf_cipher_mechs_tab[5].me_threshold = kcf_bf_threshold;
213 
214 	(void) strncpy(kcf_cipher_mechs_tab[6].me_name, SUN_CKM_AES_CBC,
215 	    CRYPTO_MAX_MECH_NAME);
216 	kcf_cipher_mechs_tab[6].me_threshold = kcf_aes_threshold;
217 
218 	(void) strncpy(kcf_cipher_mechs_tab[7].me_name, SUN_CKM_AES_ECB,
219 	    CRYPTO_MAX_MECH_NAME);
220 	kcf_cipher_mechs_tab[7].me_threshold = kcf_aes_threshold;
221 
222 	(void) strncpy(kcf_cipher_mechs_tab[8].me_name, SUN_CKM_RC4,
223 	    CRYPTO_MAX_MECH_NAME);
224 	kcf_cipher_mechs_tab[8].me_threshold = kcf_rc4_threshold;
225 
226 
227 	/* 6 HMACs */
228 	(void) strncpy(kcf_mac_mechs_tab[0].me_name, SUN_CKM_MD5_HMAC,
229 	    CRYPTO_MAX_MECH_NAME);
230 	kcf_mac_mechs_tab[0].me_threshold = kcf_md5_threshold;
231 
232 	(void) strncpy(kcf_mac_mechs_tab[1].me_name, SUN_CKM_MD5_HMAC_GENERAL,
233 	    CRYPTO_MAX_MECH_NAME);
234 	kcf_mac_mechs_tab[1].me_threshold = kcf_md5_threshold;
235 
236 	(void) strncpy(kcf_mac_mechs_tab[2].me_name, SUN_CKM_SHA1_HMAC,
237 	    CRYPTO_MAX_MECH_NAME);
238 	kcf_mac_mechs_tab[2].me_threshold = kcf_sha1_threshold;
239 
240 	(void) strncpy(kcf_mac_mechs_tab[3].me_name, SUN_CKM_SHA1_HMAC_GENERAL,
241 	    CRYPTO_MAX_MECH_NAME);
242 	kcf_mac_mechs_tab[3].me_threshold = kcf_sha1_threshold;
243 
244 	(void) strncpy(kcf_mac_mechs_tab[4].me_name, SUN_CKM_AES_GMAC,
245 	    CRYPTO_MAX_MECH_NAME);
246 	kcf_mac_mechs_tab[4].me_threshold = kcf_sha1_threshold;
247 
248 	(void) strncpy(kcf_mac_mechs_tab[5].me_name, SUN_CKM_AES_CMAC,
249 	    CRYPTO_MAX_MECH_NAME);
250 	kcf_mac_mechs_tab[5].me_threshold = kcf_sha1_threshold;
251 
252 	/* 1 random number generation pseudo mechanism */
253 	(void) strncpy(kcf_misc_mechs_tab[0].me_name, SUN_RANDOM,
254 	    CRYPTO_MAX_MECH_NAME);
255 
256 	kcf_mech_hash = mod_hash_create_strhash("kcf mech2id hash",
257 	    kcf_mech_hash_size, mod_hash_null_valdtor);
258 
259 	for (class = KCF_FIRST_OPSCLASS; class <= KCF_LAST_OPSCLASS; class++) {
260 		max = kcf_mech_tabs_tab[class].met_size;
261 		me_tab = kcf_mech_tabs_tab[class].met_tab;
262 		for (i = 0; i < max; i++) {
263 			if (me_tab[i].me_name[0] != 0) {
264 				me_tab[i].me_mechid = KCF_MECHID(class, i);
265 				(void) mod_hash_insert(kcf_mech_hash,
266 				    (mod_hash_key_t)me_tab[i].me_name,
267 				    (mod_hash_val_t)&(me_tab[i].me_mechid));
268 			}
269 		}
270 	}
271 
272 	me_mutexes = kmem_zalloc(max_ncpus * sizeof (kcf_lock_withpad_t),
273 	    KM_SLEEP);
274 	for (i = 0; i < max_ncpus; i++) {
275 		mutex_init(&me_mutexes[i].kl_lock, NULL, MUTEX_DEFAULT, NULL);
276 	}
277 }
278 
279 /*
280  * kcf_create_mech_entry()
281  *
282  * Arguments:
283  *	. The class of mechanism.
284  *	. the name of the new mechanism.
285  *
286  * Description:
287  *	Creates a new mech_entry for a mechanism not yet known to the
288  *	framework.
289  *	This routine is called by kcf_add_mech_provider, which is
290  *	in turn invoked for each mechanism supported by a provider.
291  *	The'class' argument depends on the crypto_func_group_t bitmask
292  *	in the registering provider's mech_info struct for this mechanism.
293  *	When there is ambiguity in the mapping between the crypto_func_group_t
294  *	and a class (dual ops, ...) the KCF_MISC_CLASS should be used.
295  *
296  * Context:
297  *	User context only.
298  *
299  * Returns:
300  *	KCF_INVALID_MECH_CLASS or KCF_INVALID_MECH_NAME if the class or
301  *	the mechname is bogus.
302  *	KCF_MECH_TAB_FULL when there is no room left in the mech. tabs.
303  *	KCF_SUCCESS otherwise.
304  */
305 static int
kcf_create_mech_entry(kcf_ops_class_t class,char * mechname)306 kcf_create_mech_entry(kcf_ops_class_t class, char *mechname)
307 {
308 	crypto_mech_type_t mt;
309 	kcf_mech_entry_t *me_tab;
310 	int i = 0, size;
311 
312 	if ((class < KCF_FIRST_OPSCLASS) || (class > KCF_LAST_OPSCLASS))
313 		return (KCF_INVALID_MECH_CLASS);
314 
315 	if ((mechname == NULL) || (mechname[0] == 0))
316 		return (KCF_INVALID_MECH_NAME);
317 	/*
318 	 * First check if the mechanism is already in one of the tables.
319 	 * The mech_entry could be in another class.
320 	 */
321 	mutex_enter(&kcf_mech_tabs_lock);
322 	mt = kcf_mech_hash_find(mechname);
323 	if (mt != CRYPTO_MECH_INVALID) {
324 		/* Nothing to do, regardless the suggested class. */
325 		mutex_exit(&kcf_mech_tabs_lock);
326 		return (KCF_SUCCESS);
327 	}
328 	/* Now take the next unused mech entry in the class's tab */
329 	me_tab = kcf_mech_tabs_tab[class].met_tab;
330 	size = kcf_mech_tabs_tab[class].met_size;
331 
332 	while (i < size) {
333 		ME_MUTEXES_ENTER_ALL();
334 		if (me_tab[i].me_name[0] == 0) {
335 			/* Found an empty spot */
336 			(void) strncpy(me_tab[i].me_name, mechname,
337 			    CRYPTO_MAX_MECH_NAME);
338 			me_tab[i].me_name[CRYPTO_MAX_MECH_NAME-1] = '\0';
339 			me_tab[i].me_mechid = KCF_MECHID(class, i);
340 			/*
341 			 * No a-priori information about the new mechanism, so
342 			 * the threshold is set to zero.
343 			 */
344 			me_tab[i].me_threshold = 0;
345 
346 			ME_MUTEXES_EXIT_ALL();
347 			/* Add the new mechanism to the hash table */
348 			(void) mod_hash_insert(kcf_mech_hash,
349 			    (mod_hash_key_t)me_tab[i].me_name,
350 			    (mod_hash_val_t)&(me_tab[i].me_mechid));
351 			break;
352 		}
353 		ME_MUTEXES_EXIT_ALL();
354 		i++;
355 	}
356 
357 	mutex_exit(&kcf_mech_tabs_lock);
358 
359 	if (i == size) {
360 		return (KCF_MECH_TAB_FULL);
361 	}
362 
363 	return (KCF_SUCCESS);
364 }
365 
366 /*
367  * kcf_add_mech_provider()
368  *
369  * Arguments:
370  *	. An index in to  the provider mechanism array
371  *      . A pointer to the provider descriptor
372  *	. A storage for the kcf_prov_mech_desc_t the entry was added at.
373  *
374  * Description:
375  *      Adds  a new provider of a mechanism to the mechanism's mech_entry
376  *	chain.
377  *
378  * Context:
379  *      User context only.
380  *
381  * Returns
382  *      KCF_SUCCESS on success
383  *      KCF_MECH_TAB_FULL otherwise.
384  */
385 int
kcf_add_mech_provider(short mech_indx,kcf_provider_desc_t * prov_desc,kcf_prov_mech_desc_t ** pmdpp)386 kcf_add_mech_provider(short mech_indx,
387     kcf_provider_desc_t *prov_desc, kcf_prov_mech_desc_t **pmdpp)
388 {
389 	int error;
390 	kcf_mech_entry_t *mech_entry;
391 	crypto_mech_info_t *mech_info;
392 	crypto_mech_type_t kcf_mech_type, mt;
393 	kcf_prov_mech_desc_t *prov_mech, *prov_mech2;
394 	crypto_func_group_t simple_fg_mask, dual_fg_mask;
395 	crypto_mech_info_t *dmi;
396 	crypto_mech_info_list_t *mil, *mil2;
397 	kcf_mech_entry_t *me;
398 	int i;
399 
400 	ASSERT(prov_desc->pd_prov_type != CRYPTO_LOGICAL_PROVIDER);
401 
402 	mech_info = &prov_desc->pd_mechanisms[mech_indx];
403 	/*
404 	 * Do not use the provider for the mechanism if
405 	 * policy does not allow it.
406 	 */
407 	if (is_mech_disabled(prov_desc, mech_info->cm_mech_name)) {
408 		*pmdpp = NULL;
409 		return (KCF_SUCCESS);
410 	}
411 
412 	/*
413 	 * A mechanism belongs to exactly one mechanism table.
414 	 * Find the class corresponding to the function group flag of
415 	 * the mechanism.
416 	 */
417 	kcf_mech_type = kcf_mech_hash_find(mech_info->cm_mech_name);
418 	if (kcf_mech_type == CRYPTO_MECH_INVALID) {
419 		crypto_func_group_t fg = mech_info->cm_func_group_mask;
420 		kcf_ops_class_t class;
421 
422 		if (fg & CRYPTO_FG_DIGEST || fg & CRYPTO_FG_DIGEST_ATOMIC)
423 			class = KCF_DIGEST_CLASS;
424 		else if (fg & CRYPTO_FG_ENCRYPT || fg & CRYPTO_FG_DECRYPT ||
425 		    fg & CRYPTO_FG_ENCRYPT_ATOMIC ||
426 		    fg & CRYPTO_FG_DECRYPT_ATOMIC)
427 			class = KCF_CIPHER_CLASS;
428 		else if (fg & CRYPTO_FG_MAC || fg & CRYPTO_FG_MAC_ATOMIC)
429 			class = KCF_MAC_CLASS;
430 		else if (fg & CRYPTO_FG_SIGN || fg & CRYPTO_FG_VERIFY ||
431 		    fg & CRYPTO_FG_SIGN_ATOMIC ||
432 		    fg & CRYPTO_FG_VERIFY_ATOMIC ||
433 		    fg & CRYPTO_FG_SIGN_RECOVER ||
434 		    fg & CRYPTO_FG_VERIFY_RECOVER)
435 			class = KCF_SIGN_CLASS;
436 		else if (fg & CRYPTO_FG_GENERATE ||
437 		    fg & CRYPTO_FG_GENERATE_KEY_PAIR ||
438 		    fg & CRYPTO_FG_WRAP || fg & CRYPTO_FG_UNWRAP ||
439 		    fg & CRYPTO_FG_DERIVE)
440 			class = KCF_KEYOPS_CLASS;
441 		else
442 			class = KCF_MISC_CLASS;
443 
444 		/*
445 		 * Attempt to create a new mech_entry for the specified
446 		 * mechanism. kcf_create_mech_entry() can handle the case
447 		 * where such an entry already exists.
448 		 */
449 		if ((error = kcf_create_mech_entry(class,
450 		    mech_info->cm_mech_name)) != KCF_SUCCESS) {
451 			return (error);
452 		}
453 		/* get the KCF mech type that was assigned to the mechanism */
454 		kcf_mech_type = kcf_mech_hash_find(mech_info->cm_mech_name);
455 		ASSERT(kcf_mech_type != CRYPTO_MECH_INVALID);
456 	}
457 
458 	error = kcf_get_mech_entry(kcf_mech_type, &mech_entry);
459 	ASSERT(error == KCF_SUCCESS);
460 
461 	/* allocate and initialize new kcf_prov_mech_desc */
462 	prov_mech = kmem_zalloc(sizeof (kcf_prov_mech_desc_t), KM_SLEEP);
463 	bcopy(mech_info, &prov_mech->pm_mech_info, sizeof (crypto_mech_info_t));
464 	prov_mech->pm_prov_desc = prov_desc;
465 	prov_desc->pd_mech_indx[KCF_MECH2CLASS(kcf_mech_type)]
466 	    [KCF_MECH2INDEX(kcf_mech_type)] = mech_indx;
467 
468 	KCF_PROV_REFHOLD(prov_desc);
469 
470 	dual_fg_mask = mech_info->cm_func_group_mask & CRYPTO_FG_DUAL_MASK;
471 
472 	if (dual_fg_mask == ((crypto_func_group_t)0))
473 		goto add_entry;
474 
475 	simple_fg_mask = mech_info->cm_func_group_mask &
476 	    CRYPTO_FG_SIMPLEOP_MASK | CRYPTO_FG_RANDOM;
477 
478 	for (i = 0; i < prov_desc->pd_mech_list_count; i++) {
479 		dmi = &prov_desc->pd_mechanisms[i];
480 
481 		/* skip self */
482 		if (dmi->cm_mech_number == mech_info->cm_mech_number)
483 			continue;
484 
485 		/* skip if policy doesn't allow mechanism */
486 		if (is_mech_disabled(prov_desc, dmi->cm_mech_name))
487 			continue;
488 
489 		/* skip if not a dual operation mechanism */
490 		if (!(dmi->cm_func_group_mask & dual_fg_mask) ||
491 		    (dmi->cm_func_group_mask & simple_fg_mask))
492 			continue;
493 
494 		mt = kcf_mech_hash_find(dmi->cm_mech_name);
495 		if (mt == CRYPTO_MECH_INVALID)
496 			continue;
497 
498 		if (kcf_get_mech_entry(mt, &me) != KCF_SUCCESS)
499 			continue;
500 
501 		mil = kmem_zalloc(sizeof (*mil), KM_SLEEP);
502 		mil2 = kmem_zalloc(sizeof (*mil2), KM_SLEEP);
503 
504 		/*
505 		 * Ignore hard-coded entries in the mech table
506 		 * if the provider hasn't registered.
507 		 */
508 		ME_MUTEXES_ENTER_ALL();
509 		if (me->me_hw_prov_chain == NULL && me->me_sw_prov == NULL) {
510 			ME_MUTEXES_EXIT_ALL();
511 			kmem_free(mil, sizeof (*mil));
512 			kmem_free(mil2, sizeof (*mil2));
513 			continue;
514 		}
515 
516 		/*
517 		 * Add other dual mechanisms that have registered
518 		 * with the framework to this mechanism's
519 		 * cross-reference list.
520 		 */
521 		mil->ml_mech_info = *dmi; /* struct assignment */
522 		mil->ml_kcf_mechid = mt;
523 
524 		/* add to head of list */
525 		mil->ml_next = prov_mech->pm_mi_list;
526 		prov_mech->pm_mi_list = mil;
527 
528 		if (prov_desc->pd_prov_type == CRYPTO_HW_PROVIDER)
529 			prov_mech2 = me->me_hw_prov_chain;
530 		else
531 			prov_mech2 = me->me_sw_prov;
532 
533 		if (prov_mech2 == NULL) {
534 			kmem_free(mil2, sizeof (*mil2));
535 			ME_MUTEXES_EXIT_ALL();
536 			continue;
537 		}
538 
539 		/*
540 		 * Update all other cross-reference lists by
541 		 * adding this new mechanism.
542 		 */
543 		while (prov_mech2 != NULL) {
544 			if (prov_mech2->pm_prov_desc == prov_desc) {
545 				/* struct assignment */
546 				mil2->ml_mech_info = *mech_info;
547 				mil2->ml_kcf_mechid = kcf_mech_type;
548 
549 				/* add to head of list */
550 				mil2->ml_next = prov_mech2->pm_mi_list;
551 				prov_mech2->pm_mi_list = mil2;
552 				break;
553 			}
554 			prov_mech2 = prov_mech2->pm_next;
555 		}
556 		if (prov_mech2 == NULL)
557 			kmem_free(mil2, sizeof (*mil2));
558 
559 		ME_MUTEXES_EXIT_ALL();
560 	}
561 
562 add_entry:
563 	/*
564 	 * Add new kcf_prov_mech_desc at the front of HW providers
565 	 * chain.
566 	 */
567 	switch (prov_desc->pd_prov_type) {
568 
569 	case CRYPTO_HW_PROVIDER:
570 		ME_MUTEXES_ENTER_ALL();
571 		prov_mech->pm_me = mech_entry;
572 		prov_mech->pm_next = mech_entry->me_hw_prov_chain;
573 		mech_entry->me_hw_prov_chain = prov_mech;
574 		mech_entry->me_num_hwprov++;
575 		ME_MUTEXES_EXIT_ALL();
576 		break;
577 
578 	case CRYPTO_SW_PROVIDER:
579 		ME_MUTEXES_ENTER_ALL();
580 		if (mech_entry->me_sw_prov != NULL) {
581 			/*
582 			 * There is already a SW provider for this mechanism.
583 			 * Since we allow only one SW provider per mechanism,
584 			 * report this condition.
585 			 */
586 			cmn_err(CE_WARN, "The cryptographic software provider "
587 			    "\"%s\" will not be used for %s. The provider "
588 			    "\"%s\" will be used for this mechanism "
589 			    "instead.", prov_desc->pd_description,
590 			    mech_info->cm_mech_name,
591 			    mech_entry->me_sw_prov->pm_prov_desc->
592 			    pd_description);
593 			KCF_PROV_REFRELE(prov_desc);
594 			kmem_free(prov_mech, sizeof (kcf_prov_mech_desc_t));
595 			prov_mech = NULL;
596 		} else {
597 			/*
598 			 * Set the provider as the software provider for
599 			 * this mechanism.
600 			 */
601 			mech_entry->me_sw_prov = prov_mech;
602 
603 			/* We'll wrap around after 4 billion registrations! */
604 			mech_entry->me_gen_swprov = kcf_gen_swprov++;
605 		}
606 		ME_MUTEXES_EXIT_ALL();
607 		break;
608 	}
609 
610 	*pmdpp = prov_mech;
611 
612 	return (KCF_SUCCESS);
613 }
614 
615 /*
616  * kcf_remove_mech_provider()
617  *
618  * Arguments:
619  *      . mech_name: the name of the mechanism.
620  *      . prov_desc: The provider descriptor
621  *
622  * Description:
623  *      Removes a provider from chain of provider descriptors.
624  *	The provider is made unavailable to kernel consumers for the specified
625  *	mechanism.
626  *
627  * Context:
628  *      User context only.
629  */
630 void
kcf_remove_mech_provider(char * mech_name,kcf_provider_desc_t * prov_desc)631 kcf_remove_mech_provider(char *mech_name, kcf_provider_desc_t *prov_desc)
632 {
633 	crypto_mech_type_t mech_type;
634 	kcf_prov_mech_desc_t *prov_mech, *prov_chain;
635 	kcf_prov_mech_desc_t **prev_entry_next;
636 	kcf_mech_entry_t *mech_entry;
637 	crypto_mech_info_list_t *mil, *mil2, *next, **prev_next;
638 
639 	ASSERT(prov_desc->pd_prov_type != CRYPTO_LOGICAL_PROVIDER);
640 
641 	/* get the KCF mech type that was assigned to the mechanism */
642 	if ((mech_type = kcf_mech_hash_find(mech_name)) ==
643 	    CRYPTO_MECH_INVALID) {
644 		/*
645 		 * Provider was not allowed for this mech due to policy or
646 		 * configuration.
647 		 */
648 		return;
649 	}
650 
651 	/* get a ptr to the mech_entry that was created */
652 	if (kcf_get_mech_entry(mech_type, &mech_entry) != KCF_SUCCESS) {
653 		/*
654 		 * Provider was not allowed for this mech due to policy or
655 		 * configuration.
656 		 */
657 		return;
658 	}
659 
660 	ME_MUTEXES_ENTER_ALL();
661 
662 	switch (prov_desc->pd_prov_type) {
663 
664 	case CRYPTO_HW_PROVIDER:
665 		/* find the provider in the mech_entry chain */
666 		prev_entry_next = &mech_entry->me_hw_prov_chain;
667 		prov_mech = mech_entry->me_hw_prov_chain;
668 		while (prov_mech != NULL &&
669 		    prov_mech->pm_prov_desc != prov_desc) {
670 			prev_entry_next = &prov_mech->pm_next;
671 			prov_mech = prov_mech->pm_next;
672 		}
673 
674 		if (prov_mech == NULL) {
675 			/* entry not found, simply return */
676 			ME_MUTEXES_EXIT_ALL();
677 			return;
678 		}
679 
680 		/* remove provider entry from mech_entry chain */
681 		*prev_entry_next = prov_mech->pm_next;
682 		ASSERT(mech_entry->me_num_hwprov > 0);
683 		mech_entry->me_num_hwprov--;
684 		break;
685 
686 	case CRYPTO_SW_PROVIDER:
687 		if (mech_entry->me_sw_prov == NULL ||
688 		    mech_entry->me_sw_prov->pm_prov_desc != prov_desc) {
689 			/* not the software provider for this mechanism */
690 			ME_MUTEXES_EXIT_ALL();
691 			return;
692 		}
693 		prov_mech = mech_entry->me_sw_prov;
694 		mech_entry->me_sw_prov = NULL;
695 		break;
696 	}
697 
698 	ME_MUTEXES_EXIT_ALL();
699 
700 	/* Free the dual ops cross-reference lists  */
701 	mil = prov_mech->pm_mi_list;
702 	while (mil != NULL) {
703 		next = mil->ml_next;
704 		if (kcf_get_mech_entry(mil->ml_kcf_mechid,
705 		    &mech_entry) != KCF_SUCCESS) {
706 			mil = next;
707 			continue;
708 		}
709 
710 		ME_MUTEXES_ENTER_ALL();
711 		if (prov_desc->pd_prov_type == CRYPTO_HW_PROVIDER)
712 			prov_chain = mech_entry->me_hw_prov_chain;
713 		else
714 			prov_chain = mech_entry->me_sw_prov;
715 
716 		while (prov_chain != NULL) {
717 			if (prov_chain->pm_prov_desc == prov_desc) {
718 				prev_next = &prov_chain->pm_mi_list;
719 				mil2 = prov_chain->pm_mi_list;
720 				while (mil2 != NULL &&
721 				    mil2->ml_kcf_mechid != mech_type) {
722 					prev_next = &mil2->ml_next;
723 					mil2 = mil2->ml_next;
724 				}
725 				if (mil2 != NULL) {
726 					*prev_next = mil2->ml_next;
727 					kmem_free(mil2, sizeof (*mil2));
728 				}
729 				break;
730 			}
731 			prov_chain = prov_chain->pm_next;
732 		}
733 
734 		ME_MUTEXES_EXIT_ALL();
735 		kmem_free(mil, sizeof (crypto_mech_info_list_t));
736 		mil = next;
737 	}
738 
739 	/* free entry  */
740 	KCF_PROV_REFRELE(prov_mech->pm_prov_desc);
741 	kmem_free(prov_mech, sizeof (kcf_prov_mech_desc_t));
742 }
743 
744 /*
745  * kcf_get_mech_entry()
746  *
747  * Arguments:
748  *      . The framework mechanism type
749  *      . Storage for the mechanism entry
750  *
751  * Description:
752  *      Retrieves the mechanism entry for the mech.
753  *
754  * Context:
755  *      User and interrupt contexts.
756  *
757  * Returns:
758  *      KCF_MECHANISM_XXX appropriate error code.
759  *      KCF_SUCCESS otherwise.
760  */
761 int
kcf_get_mech_entry(crypto_mech_type_t mech_type,kcf_mech_entry_t ** mep)762 kcf_get_mech_entry(crypto_mech_type_t mech_type, kcf_mech_entry_t **mep)
763 {
764 	kcf_ops_class_t		class;
765 	int			index;
766 	kcf_mech_entry_tab_t	*me_tab;
767 
768 	ASSERT(mep != NULL);
769 
770 	class = KCF_MECH2CLASS(mech_type);
771 
772 	if ((class < KCF_FIRST_OPSCLASS) || (class > KCF_LAST_OPSCLASS)) {
773 		/* the caller won't need to know it's an invalid class */
774 		return (KCF_INVALID_MECH_NUMBER);
775 	}
776 
777 	me_tab = &kcf_mech_tabs_tab[class];
778 	index = KCF_MECH2INDEX(mech_type);
779 
780 	if ((index < 0) || (index >= me_tab->met_size)) {
781 		return (KCF_INVALID_MECH_NUMBER);
782 	}
783 
784 	*mep = &((me_tab->met_tab)[index]);
785 
786 	return (KCF_SUCCESS);
787 }
788 
789 /*
790  * Returns TRUE if the provider is usable and the MOD_NOAUTOUNLOAD flag
791  * is set in the modctl structure.
792  */
793 static boolean_t
auto_unload_flag_set(kcf_prov_mech_desc_t * pm)794 auto_unload_flag_set(kcf_prov_mech_desc_t *pm)
795 {
796 	kcf_provider_desc_t *pd;
797 	struct modctl *mp;
798 	boolean_t ret = B_FALSE;
799 
800 	if (pm != NULL) {
801 		pd = pm->pm_prov_desc;
802 		KCF_PROV_REFHOLD(pd);
803 
804 		if (KCF_IS_PROV_USABLE(pd)) {
805 			mp = pd->pd_mctlp;
806 			if (mp->mod_loadflags & MOD_NOAUTOUNLOAD) {
807 				ret = B_TRUE;
808 			}
809 		}
810 		KCF_PROV_REFRELE(pd);
811 	}
812 
813 	return (ret);
814 }
815 
816 /*
817  * Lookup the hash table for an entry that matches the mechname.
818  * If there are no hardware or software providers for the mechanism,
819  * but there is an unloaded software provider, this routine will attempt
820  * to load it.
821  *
822  * If the MOD_NOAUTOUNLOAD flag is not set, a software provider is
823  * in constant danger of being unloaded.  For consumers that call
824  * crypto_mech2id() only once, the provider will not be reloaded
825  * if it becomes unloaded.  If a provider gets loaded elsewhere
826  * without the MOD_NOAUTOUNLOAD flag being set, we set it now.
827  */
828 crypto_mech_type_t
crypto_mech2id_common(char * mechname,boolean_t load_module)829 crypto_mech2id_common(char *mechname, boolean_t load_module)
830 {
831 	crypto_mech_type_t mt;
832 	kcf_mech_entry_t *me;
833 	int i;
834 	kcf_ops_class_t class;
835 	boolean_t second_time = B_FALSE;
836 	boolean_t try_to_load_software_provider = B_FALSE;
837 	kcf_lock_withpad_t *mp;
838 
839 try_again:
840 	mt = kcf_mech_hash_find(mechname);
841 	if (!load_module || second_time == B_TRUE || servicing_interrupt())
842 		return (mt);
843 
844 	if (mt != CRYPTO_MECH_INVALID) {
845 		class = KCF_MECH2CLASS(mt);
846 		i = KCF_MECH2INDEX(mt);
847 		me = &(kcf_mech_tabs_tab[class].met_tab[i]);
848 		mp = &me_mutexes[CPU_SEQID];
849 		mutex_enter(&mp->kl_lock);
850 
851 		if (load_module && !auto_unload_flag_set(me->me_sw_prov)) {
852 			try_to_load_software_provider = B_TRUE;
853 		}
854 		mutex_exit(&mp->kl_lock);
855 	}
856 
857 	if (mt == CRYPTO_MECH_INVALID || try_to_load_software_provider) {
858 		struct modctl *mcp;
859 		boolean_t load_again = B_FALSE;
860 		char *module_name;
861 		int module_name_size;
862 
863 		/* try to find a software provider for the mechanism */
864 		if (get_sw_provider_for_mech(mechname, &module_name)
865 		    != CRYPTO_SUCCESS) {
866 			/* mt may already be set for a hw provider */
867 			return (mt);
868 		}
869 
870 		module_name_size = strlen(module_name) + 1;
871 		if (modload("crypto", module_name) == -1 ||
872 		    (mcp = mod_hold_by_name(module_name)) == NULL) {
873 			kmem_free(module_name, module_name_size);
874 			/* mt may already be set for a hw provider */
875 			return (mt);
876 		}
877 
878 		mcp->mod_loadflags |= MOD_NOAUTOUNLOAD;
879 
880 		/* memory pressure may have unloaded the module */
881 		if (!mcp->mod_installed)
882 			load_again = B_TRUE;
883 		mod_release_mod(mcp);
884 
885 		if (load_again)
886 			(void) modload("crypto", module_name);
887 
888 		kmem_free(module_name, module_name_size);
889 
890 		/* mt may already be set for a hw provider */
891 		if (mt != CRYPTO_MECH_INVALID)
892 			return (mt);
893 
894 		/*
895 		 * Try again.  Should find a software provider in the
896 		 * table this time around.
897 		 */
898 		second_time = B_TRUE;
899 		goto try_again;
900 	}
901 
902 	return (mt);
903 }
904