xref: /freebsd/sys/contrib/openzfs/module/icp/algs/aes/aes_impl.c (revision 6be3386466ab79a84b48429ae66244f21526d3df)
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 (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 #include <sys/zfs_context.h>
26 #include <sys/crypto/icp.h>
27 #include <sys/crypto/spi.h>
28 #include <sys/simd.h>
29 #include <modes/modes.h>
30 #include <aes/aes_impl.h>
31 
32 /*
33  * Initialize AES encryption and decryption key schedules.
34  *
35  * Parameters:
36  * cipherKey	User key
37  * keyBits	AES key size (128, 192, or 256 bits)
38  * keysched	AES key schedule to be initialized, of type aes_key_t.
39  *		Allocated by aes_alloc_keysched().
40  */
41 void
42 aes_init_keysched(const uint8_t *cipherKey, uint_t keyBits, void *keysched)
43 {
44 	const aes_impl_ops_t *ops = aes_impl_get_ops();
45 	aes_key_t *newbie = keysched;
46 	uint_t keysize, i, j;
47 	union {
48 		uint64_t	ka64[4];
49 		uint32_t	ka32[8];
50 		} keyarr;
51 
52 	switch (keyBits) {
53 	case 128:
54 		newbie->nr = 10;
55 		break;
56 
57 	case 192:
58 		newbie->nr = 12;
59 		break;
60 
61 	case 256:
62 		newbie->nr = 14;
63 		break;
64 
65 	default:
66 		/* should never get here */
67 		return;
68 	}
69 	keysize = CRYPTO_BITS2BYTES(keyBits);
70 
71 	/*
72 	 * Generic C implementation requires byteswap for little endian
73 	 * machines, various accelerated implementations for various
74 	 * architectures may not.
75 	 */
76 	if (!ops->needs_byteswap) {
77 		/* no byteswap needed */
78 		if (IS_P2ALIGNED(cipherKey, sizeof (uint64_t))) {
79 			for (i = 0, j = 0; j < keysize; i++, j += 8) {
80 				/* LINTED: pointer alignment */
81 				keyarr.ka64[i] = *((uint64_t *)&cipherKey[j]);
82 			}
83 		} else {
84 			bcopy(cipherKey, keyarr.ka32, keysize);
85 		}
86 	} else {
87 		/* byte swap */
88 		for (i = 0, j = 0; j < keysize; i++, j += 4) {
89 			keyarr.ka32[i] =
90 			    htonl(*(uint32_t *)(void *)&cipherKey[j]);
91 		}
92 	}
93 
94 	ops->generate(newbie, keyarr.ka32, keyBits);
95 	newbie->ops = ops;
96 
97 	/*
98 	 * Note: if there are systems that need the AES_64BIT_KS type in the
99 	 * future, move setting key schedule type to individual implementations
100 	 */
101 	newbie->type = AES_32BIT_KS;
102 }
103 
104 
105 /*
106  * Encrypt one block using AES.
107  * Align if needed and (for x86 32-bit only) byte-swap.
108  *
109  * Parameters:
110  * ks	Key schedule, of type aes_key_t
111  * pt	Input block (plain text)
112  * ct	Output block (crypto text).  Can overlap with pt
113  */
114 int
115 aes_encrypt_block(const void *ks, const uint8_t *pt, uint8_t *ct)
116 {
117 	aes_key_t	*ksch = (aes_key_t *)ks;
118 	const aes_impl_ops_t	*ops = ksch->ops;
119 
120 	if (IS_P2ALIGNED2(pt, ct, sizeof (uint32_t)) && !ops->needs_byteswap) {
121 		/* LINTED:  pointer alignment */
122 		ops->encrypt(&ksch->encr_ks.ks32[0], ksch->nr,
123 		    /* LINTED:  pointer alignment */
124 		    (uint32_t *)pt, (uint32_t *)ct);
125 	} else {
126 		uint32_t buffer[AES_BLOCK_LEN / sizeof (uint32_t)];
127 
128 		/* Copy input block into buffer */
129 		if (ops->needs_byteswap) {
130 			buffer[0] = htonl(*(uint32_t *)(void *)&pt[0]);
131 			buffer[1] = htonl(*(uint32_t *)(void *)&pt[4]);
132 			buffer[2] = htonl(*(uint32_t *)(void *)&pt[8]);
133 			buffer[3] = htonl(*(uint32_t *)(void *)&pt[12]);
134 		} else
135 			bcopy(pt, &buffer, AES_BLOCK_LEN);
136 
137 		ops->encrypt(&ksch->encr_ks.ks32[0], ksch->nr, buffer, buffer);
138 
139 		/* Copy result from buffer to output block */
140 		if (ops->needs_byteswap) {
141 			*(uint32_t *)(void *)&ct[0] = htonl(buffer[0]);
142 			*(uint32_t *)(void *)&ct[4] = htonl(buffer[1]);
143 			*(uint32_t *)(void *)&ct[8] = htonl(buffer[2]);
144 			*(uint32_t *)(void *)&ct[12] = htonl(buffer[3]);
145 		} else
146 			bcopy(&buffer, ct, AES_BLOCK_LEN);
147 	}
148 	return (CRYPTO_SUCCESS);
149 }
150 
151 
152 /*
153  * Decrypt one block using AES.
154  * Align and byte-swap if needed.
155  *
156  * Parameters:
157  * ks	Key schedule, of type aes_key_t
158  * ct	Input block (crypto text)
159  * pt	Output block (plain text). Can overlap with pt
160  */
161 int
162 aes_decrypt_block(const void *ks, const uint8_t *ct, uint8_t *pt)
163 {
164 	aes_key_t	*ksch = (aes_key_t *)ks;
165 	const aes_impl_ops_t	*ops = ksch->ops;
166 
167 	if (IS_P2ALIGNED2(ct, pt, sizeof (uint32_t)) && !ops->needs_byteswap) {
168 		/* LINTED:  pointer alignment */
169 		ops->decrypt(&ksch->decr_ks.ks32[0], ksch->nr,
170 		    /* LINTED:  pointer alignment */
171 		    (uint32_t *)ct, (uint32_t *)pt);
172 	} else {
173 		uint32_t buffer[AES_BLOCK_LEN / sizeof (uint32_t)];
174 
175 		/* Copy input block into buffer */
176 		if (ops->needs_byteswap) {
177 			buffer[0] = htonl(*(uint32_t *)(void *)&ct[0]);
178 			buffer[1] = htonl(*(uint32_t *)(void *)&ct[4]);
179 			buffer[2] = htonl(*(uint32_t *)(void *)&ct[8]);
180 			buffer[3] = htonl(*(uint32_t *)(void *)&ct[12]);
181 		} else
182 			bcopy(ct, &buffer, AES_BLOCK_LEN);
183 
184 		ops->decrypt(&ksch->decr_ks.ks32[0], ksch->nr, buffer, buffer);
185 
186 		/* Copy result from buffer to output block */
187 		if (ops->needs_byteswap) {
188 			*(uint32_t *)(void *)&pt[0] = htonl(buffer[0]);
189 			*(uint32_t *)(void *)&pt[4] = htonl(buffer[1]);
190 			*(uint32_t *)(void *)&pt[8] = htonl(buffer[2]);
191 			*(uint32_t *)(void *)&pt[12] = htonl(buffer[3]);
192 		} else
193 			bcopy(&buffer, pt, AES_BLOCK_LEN);
194 	}
195 	return (CRYPTO_SUCCESS);
196 }
197 
198 
199 /*
200  * Allocate key schedule for AES.
201  *
202  * Return the pointer and set size to the number of bytes allocated.
203  * Memory allocated must be freed by the caller when done.
204  *
205  * Parameters:
206  * size		Size of key schedule allocated, in bytes
207  * kmflag	Flag passed to kmem_alloc(9F); ignored in userland.
208  */
209 /* ARGSUSED */
210 void *
211 aes_alloc_keysched(size_t *size, int kmflag)
212 {
213 	aes_key_t *keysched;
214 
215 	keysched = (aes_key_t *)kmem_alloc(sizeof (aes_key_t), kmflag);
216 	if (keysched != NULL) {
217 		*size = sizeof (aes_key_t);
218 		return (keysched);
219 	}
220 	return (NULL);
221 }
222 
223 /* AES implementation that contains the fastest methods */
224 static aes_impl_ops_t aes_fastest_impl = {
225 	.name = "fastest"
226 };
227 
228 /* All compiled in implementations */
229 const aes_impl_ops_t *aes_all_impl[] = {
230 	&aes_generic_impl,
231 #if defined(__x86_64)
232 	&aes_x86_64_impl,
233 #endif
234 #if defined(__x86_64) && defined(HAVE_AES)
235 	&aes_aesni_impl,
236 #endif
237 };
238 
239 /* Indicate that benchmark has been completed */
240 static boolean_t aes_impl_initialized = B_FALSE;
241 
242 /* Select aes implementation */
243 #define	IMPL_FASTEST	(UINT32_MAX)
244 #define	IMPL_CYCLE	(UINT32_MAX-1)
245 
246 #define	AES_IMPL_READ(i) (*(volatile uint32_t *) &(i))
247 
248 static uint32_t icp_aes_impl = IMPL_FASTEST;
249 static uint32_t user_sel_impl = IMPL_FASTEST;
250 
251 /* Hold all supported implementations */
252 static size_t aes_supp_impl_cnt = 0;
253 static aes_impl_ops_t *aes_supp_impl[ARRAY_SIZE(aes_all_impl)];
254 
255 /*
256  * Returns the AES operations for encrypt/decrypt/key setup.  When a
257  * SIMD implementation is not allowed in the current context, then
258  * fallback to the fastest generic implementation.
259  */
260 const aes_impl_ops_t *
261 aes_impl_get_ops(void)
262 {
263 	if (!kfpu_allowed())
264 		return (&aes_generic_impl);
265 
266 	const aes_impl_ops_t *ops = NULL;
267 	const uint32_t impl = AES_IMPL_READ(icp_aes_impl);
268 
269 	switch (impl) {
270 	case IMPL_FASTEST:
271 		ASSERT(aes_impl_initialized);
272 		ops = &aes_fastest_impl;
273 		break;
274 	case IMPL_CYCLE:
275 		/* Cycle through supported implementations */
276 		ASSERT(aes_impl_initialized);
277 		ASSERT3U(aes_supp_impl_cnt, >, 0);
278 		static size_t cycle_impl_idx = 0;
279 		size_t idx = (++cycle_impl_idx) % aes_supp_impl_cnt;
280 		ops = aes_supp_impl[idx];
281 		break;
282 	default:
283 		ASSERT3U(impl, <, aes_supp_impl_cnt);
284 		ASSERT3U(aes_supp_impl_cnt, >, 0);
285 		if (impl < ARRAY_SIZE(aes_all_impl))
286 			ops = aes_supp_impl[impl];
287 		break;
288 	}
289 
290 	ASSERT3P(ops, !=, NULL);
291 
292 	return (ops);
293 }
294 
295 /*
296  * Initialize all supported implementations.
297  */
298 void
299 aes_impl_init(void)
300 {
301 	aes_impl_ops_t *curr_impl;
302 	int i, c;
303 
304 	/* Move supported implementations into aes_supp_impls */
305 	for (i = 0, c = 0; i < ARRAY_SIZE(aes_all_impl); i++) {
306 		curr_impl = (aes_impl_ops_t *)aes_all_impl[i];
307 
308 		if (curr_impl->is_supported())
309 			aes_supp_impl[c++] = (aes_impl_ops_t *)curr_impl;
310 	}
311 	aes_supp_impl_cnt = c;
312 
313 	/*
314 	 * Set the fastest implementation given the assumption that the
315 	 * hardware accelerated version is the fastest.
316 	 */
317 #if defined(__x86_64)
318 #if defined(HAVE_AES)
319 	if (aes_aesni_impl.is_supported()) {
320 		memcpy(&aes_fastest_impl, &aes_aesni_impl,
321 		    sizeof (aes_fastest_impl));
322 	} else
323 #endif
324 	{
325 		memcpy(&aes_fastest_impl, &aes_x86_64_impl,
326 		    sizeof (aes_fastest_impl));
327 	}
328 #else
329 	memcpy(&aes_fastest_impl, &aes_generic_impl,
330 	    sizeof (aes_fastest_impl));
331 #endif
332 
333 	strlcpy(aes_fastest_impl.name, "fastest", AES_IMPL_NAME_MAX);
334 
335 	/* Finish initialization */
336 	atomic_swap_32(&icp_aes_impl, user_sel_impl);
337 	aes_impl_initialized = B_TRUE;
338 }
339 
340 static const struct {
341 	char *name;
342 	uint32_t sel;
343 } aes_impl_opts[] = {
344 		{ "cycle",	IMPL_CYCLE },
345 		{ "fastest",	IMPL_FASTEST },
346 };
347 
348 /*
349  * Function sets desired aes implementation.
350  *
351  * If we are called before init(), user preference will be saved in
352  * user_sel_impl, and applied in later init() call. This occurs when module
353  * parameter is specified on module load. Otherwise, directly update
354  * icp_aes_impl.
355  *
356  * @val		Name of aes implementation to use
357  * @param	Unused.
358  */
359 int
360 aes_impl_set(const char *val)
361 {
362 	int err = -EINVAL;
363 	char req_name[AES_IMPL_NAME_MAX];
364 	uint32_t impl = AES_IMPL_READ(user_sel_impl);
365 	size_t i;
366 
367 	/* sanitize input */
368 	i = strnlen(val, AES_IMPL_NAME_MAX);
369 	if (i == 0 || i >= AES_IMPL_NAME_MAX)
370 		return (err);
371 
372 	strlcpy(req_name, val, AES_IMPL_NAME_MAX);
373 	while (i > 0 && isspace(req_name[i-1]))
374 		i--;
375 	req_name[i] = '\0';
376 
377 	/* Check mandatory options */
378 	for (i = 0; i < ARRAY_SIZE(aes_impl_opts); i++) {
379 		if (strcmp(req_name, aes_impl_opts[i].name) == 0) {
380 			impl = aes_impl_opts[i].sel;
381 			err = 0;
382 			break;
383 		}
384 	}
385 
386 	/* check all supported impl if init() was already called */
387 	if (err != 0 && aes_impl_initialized) {
388 		/* check all supported implementations */
389 		for (i = 0; i < aes_supp_impl_cnt; i++) {
390 			if (strcmp(req_name, aes_supp_impl[i]->name) == 0) {
391 				impl = i;
392 				err = 0;
393 				break;
394 			}
395 		}
396 	}
397 
398 	if (err == 0) {
399 		if (aes_impl_initialized)
400 			atomic_swap_32(&icp_aes_impl, impl);
401 		else
402 			atomic_swap_32(&user_sel_impl, impl);
403 	}
404 
405 	return (err);
406 }
407 
408 #if defined(_KERNEL) && defined(__linux__)
409 
410 static int
411 icp_aes_impl_set(const char *val, zfs_kernel_param_t *kp)
412 {
413 	return (aes_impl_set(val));
414 }
415 
416 static int
417 icp_aes_impl_get(char *buffer, zfs_kernel_param_t *kp)
418 {
419 	int i, cnt = 0;
420 	char *fmt;
421 	const uint32_t impl = AES_IMPL_READ(icp_aes_impl);
422 
423 	ASSERT(aes_impl_initialized);
424 
425 	/* list mandatory options */
426 	for (i = 0; i < ARRAY_SIZE(aes_impl_opts); i++) {
427 		fmt = (impl == aes_impl_opts[i].sel) ? "[%s] " : "%s ";
428 		cnt += sprintf(buffer + cnt, fmt, aes_impl_opts[i].name);
429 	}
430 
431 	/* list all supported implementations */
432 	for (i = 0; i < aes_supp_impl_cnt; i++) {
433 		fmt = (i == impl) ? "[%s] " : "%s ";
434 		cnt += sprintf(buffer + cnt, fmt, aes_supp_impl[i]->name);
435 	}
436 
437 	return (cnt);
438 }
439 
440 module_param_call(icp_aes_impl, icp_aes_impl_set, icp_aes_impl_get,
441     NULL, 0644);
442 MODULE_PARM_DESC(icp_aes_impl, "Select aes implementation.");
443 #endif
444