xref: /openbmc/linux/drivers/crypto/padlock-sha.c (revision 9cfc5c90)
1 /*
2  * Cryptographic API.
3  *
4  * Support for VIA PadLock hardware crypto engine.
5  *
6  * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  */
14 
15 #include <crypto/internal/hash.h>
16 #include <crypto/padlock.h>
17 #include <crypto/sha.h>
18 #include <linux/err.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/errno.h>
22 #include <linux/interrupt.h>
23 #include <linux/kernel.h>
24 #include <linux/scatterlist.h>
25 #include <asm/cpu_device_id.h>
26 #include <asm/fpu/api.h>
27 
28 struct padlock_sha_desc {
29 	struct shash_desc fallback;
30 };
31 
32 struct padlock_sha_ctx {
33 	struct crypto_shash *fallback;
34 };
35 
36 static int padlock_sha_init(struct shash_desc *desc)
37 {
38 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
39 	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
40 
41 	dctx->fallback.tfm = ctx->fallback;
42 	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
43 	return crypto_shash_init(&dctx->fallback);
44 }
45 
46 static int padlock_sha_update(struct shash_desc *desc,
47 			      const u8 *data, unsigned int length)
48 {
49 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
50 
51 	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
52 	return crypto_shash_update(&dctx->fallback, data, length);
53 }
54 
55 static int padlock_sha_export(struct shash_desc *desc, void *out)
56 {
57 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
58 
59 	return crypto_shash_export(&dctx->fallback, out);
60 }
61 
62 static int padlock_sha_import(struct shash_desc *desc, const void *in)
63 {
64 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
65 	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
66 
67 	dctx->fallback.tfm = ctx->fallback;
68 	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
69 	return crypto_shash_import(&dctx->fallback, in);
70 }
71 
72 static inline void padlock_output_block(uint32_t *src,
73 		 	uint32_t *dst, size_t count)
74 {
75 	while (count--)
76 		*dst++ = swab32(*src++);
77 }
78 
79 static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
80 			      unsigned int count, u8 *out)
81 {
82 	/* We can't store directly to *out as it may be unaligned. */
83 	/* BTW Don't reduce the buffer size below 128 Bytes!
84 	 *     PadLock microcode needs it that big. */
85 	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
86 		((aligned(STACK_ALIGN)));
87 	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
88 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
89 	struct sha1_state state;
90 	unsigned int space;
91 	unsigned int leftover;
92 	int ts_state;
93 	int err;
94 
95 	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
96 	err = crypto_shash_export(&dctx->fallback, &state);
97 	if (err)
98 		goto out;
99 
100 	if (state.count + count > ULONG_MAX)
101 		return crypto_shash_finup(&dctx->fallback, in, count, out);
102 
103 	leftover = ((state.count - 1) & (SHA1_BLOCK_SIZE - 1)) + 1;
104 	space =  SHA1_BLOCK_SIZE - leftover;
105 	if (space) {
106 		if (count > space) {
107 			err = crypto_shash_update(&dctx->fallback, in, space) ?:
108 			      crypto_shash_export(&dctx->fallback, &state);
109 			if (err)
110 				goto out;
111 			count -= space;
112 			in += space;
113 		} else {
114 			memcpy(state.buffer + leftover, in, count);
115 			in = state.buffer;
116 			count += leftover;
117 			state.count &= ~(SHA1_BLOCK_SIZE - 1);
118 		}
119 	}
120 
121 	memcpy(result, &state.state, SHA1_DIGEST_SIZE);
122 
123 	/* prevent taking the spurious DNA fault with padlock. */
124 	ts_state = irq_ts_save();
125 	asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
126 		      : \
127 		      : "c"((unsigned long)state.count + count), \
128 			"a"((unsigned long)state.count), \
129 			"S"(in), "D"(result));
130 	irq_ts_restore(ts_state);
131 
132 	padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
133 
134 out:
135 	return err;
136 }
137 
138 static int padlock_sha1_final(struct shash_desc *desc, u8 *out)
139 {
140 	u8 buf[4];
141 
142 	return padlock_sha1_finup(desc, buf, 0, out);
143 }
144 
145 static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
146 				unsigned int count, u8 *out)
147 {
148 	/* We can't store directly to *out as it may be unaligned. */
149 	/* BTW Don't reduce the buffer size below 128 Bytes!
150 	 *     PadLock microcode needs it that big. */
151 	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
152 		((aligned(STACK_ALIGN)));
153 	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
154 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
155 	struct sha256_state state;
156 	unsigned int space;
157 	unsigned int leftover;
158 	int ts_state;
159 	int err;
160 
161 	dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
162 	err = crypto_shash_export(&dctx->fallback, &state);
163 	if (err)
164 		goto out;
165 
166 	if (state.count + count > ULONG_MAX)
167 		return crypto_shash_finup(&dctx->fallback, in, count, out);
168 
169 	leftover = ((state.count - 1) & (SHA256_BLOCK_SIZE - 1)) + 1;
170 	space =  SHA256_BLOCK_SIZE - leftover;
171 	if (space) {
172 		if (count > space) {
173 			err = crypto_shash_update(&dctx->fallback, in, space) ?:
174 			      crypto_shash_export(&dctx->fallback, &state);
175 			if (err)
176 				goto out;
177 			count -= space;
178 			in += space;
179 		} else {
180 			memcpy(state.buf + leftover, in, count);
181 			in = state.buf;
182 			count += leftover;
183 			state.count &= ~(SHA1_BLOCK_SIZE - 1);
184 		}
185 	}
186 
187 	memcpy(result, &state.state, SHA256_DIGEST_SIZE);
188 
189 	/* prevent taking the spurious DNA fault with padlock. */
190 	ts_state = irq_ts_save();
191 	asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
192 		      : \
193 		      : "c"((unsigned long)state.count + count), \
194 			"a"((unsigned long)state.count), \
195 			"S"(in), "D"(result));
196 	irq_ts_restore(ts_state);
197 
198 	padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
199 
200 out:
201 	return err;
202 }
203 
204 static int padlock_sha256_final(struct shash_desc *desc, u8 *out)
205 {
206 	u8 buf[4];
207 
208 	return padlock_sha256_finup(desc, buf, 0, out);
209 }
210 
211 static int padlock_cra_init(struct crypto_tfm *tfm)
212 {
213 	struct crypto_shash *hash = __crypto_shash_cast(tfm);
214 	const char *fallback_driver_name = crypto_tfm_alg_name(tfm);
215 	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
216 	struct crypto_shash *fallback_tfm;
217 	int err = -ENOMEM;
218 
219 	/* Allocate a fallback and abort if it failed. */
220 	fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
221 					  CRYPTO_ALG_NEED_FALLBACK);
222 	if (IS_ERR(fallback_tfm)) {
223 		printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
224 		       fallback_driver_name);
225 		err = PTR_ERR(fallback_tfm);
226 		goto out;
227 	}
228 
229 	ctx->fallback = fallback_tfm;
230 	hash->descsize += crypto_shash_descsize(fallback_tfm);
231 	return 0;
232 
233 out:
234 	return err;
235 }
236 
237 static void padlock_cra_exit(struct crypto_tfm *tfm)
238 {
239 	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
240 
241 	crypto_free_shash(ctx->fallback);
242 }
243 
244 static struct shash_alg sha1_alg = {
245 	.digestsize	=	SHA1_DIGEST_SIZE,
246 	.init   	= 	padlock_sha_init,
247 	.update 	=	padlock_sha_update,
248 	.finup  	=	padlock_sha1_finup,
249 	.final  	=	padlock_sha1_final,
250 	.export		=	padlock_sha_export,
251 	.import		=	padlock_sha_import,
252 	.descsize	=	sizeof(struct padlock_sha_desc),
253 	.statesize	=	sizeof(struct sha1_state),
254 	.base		=	{
255 		.cra_name		=	"sha1",
256 		.cra_driver_name	=	"sha1-padlock",
257 		.cra_priority		=	PADLOCK_CRA_PRIORITY,
258 		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH |
259 						CRYPTO_ALG_NEED_FALLBACK,
260 		.cra_blocksize		=	SHA1_BLOCK_SIZE,
261 		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
262 		.cra_module		=	THIS_MODULE,
263 		.cra_init		=	padlock_cra_init,
264 		.cra_exit		=	padlock_cra_exit,
265 	}
266 };
267 
268 static struct shash_alg sha256_alg = {
269 	.digestsize	=	SHA256_DIGEST_SIZE,
270 	.init   	= 	padlock_sha_init,
271 	.update 	=	padlock_sha_update,
272 	.finup  	=	padlock_sha256_finup,
273 	.final  	=	padlock_sha256_final,
274 	.export		=	padlock_sha_export,
275 	.import		=	padlock_sha_import,
276 	.descsize	=	sizeof(struct padlock_sha_desc),
277 	.statesize	=	sizeof(struct sha256_state),
278 	.base		=	{
279 		.cra_name		=	"sha256",
280 		.cra_driver_name	=	"sha256-padlock",
281 		.cra_priority		=	PADLOCK_CRA_PRIORITY,
282 		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH |
283 						CRYPTO_ALG_NEED_FALLBACK,
284 		.cra_blocksize		=	SHA256_BLOCK_SIZE,
285 		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
286 		.cra_module		=	THIS_MODULE,
287 		.cra_init		=	padlock_cra_init,
288 		.cra_exit		=	padlock_cra_exit,
289 	}
290 };
291 
292 /* Add two shash_alg instance for hardware-implemented *
293 * multiple-parts hash supported by VIA Nano Processor.*/
294 static int padlock_sha1_init_nano(struct shash_desc *desc)
295 {
296 	struct sha1_state *sctx = shash_desc_ctx(desc);
297 
298 	*sctx = (struct sha1_state){
299 		.state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
300 	};
301 
302 	return 0;
303 }
304 
305 static int padlock_sha1_update_nano(struct shash_desc *desc,
306 			const u8 *data,	unsigned int len)
307 {
308 	struct sha1_state *sctx = shash_desc_ctx(desc);
309 	unsigned int partial, done;
310 	const u8 *src;
311 	/*The PHE require the out buffer must 128 bytes and 16-bytes aligned*/
312 	u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
313 		((aligned(STACK_ALIGN)));
314 	u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
315 	int ts_state;
316 
317 	partial = sctx->count & 0x3f;
318 	sctx->count += len;
319 	done = 0;
320 	src = data;
321 	memcpy(dst, (u8 *)(sctx->state), SHA1_DIGEST_SIZE);
322 
323 	if ((partial + len) >= SHA1_BLOCK_SIZE) {
324 
325 		/* Append the bytes in state's buffer to a block to handle */
326 		if (partial) {
327 			done = -partial;
328 			memcpy(sctx->buffer + partial, data,
329 				done + SHA1_BLOCK_SIZE);
330 			src = sctx->buffer;
331 			ts_state = irq_ts_save();
332 			asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
333 			: "+S"(src), "+D"(dst) \
334 			: "a"((long)-1), "c"((unsigned long)1));
335 			irq_ts_restore(ts_state);
336 			done += SHA1_BLOCK_SIZE;
337 			src = data + done;
338 		}
339 
340 		/* Process the left bytes from the input data */
341 		if (len - done >= SHA1_BLOCK_SIZE) {
342 			ts_state = irq_ts_save();
343 			asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
344 			: "+S"(src), "+D"(dst)
345 			: "a"((long)-1),
346 			"c"((unsigned long)((len - done) / SHA1_BLOCK_SIZE)));
347 			irq_ts_restore(ts_state);
348 			done += ((len - done) - (len - done) % SHA1_BLOCK_SIZE);
349 			src = data + done;
350 		}
351 		partial = 0;
352 	}
353 	memcpy((u8 *)(sctx->state), dst, SHA1_DIGEST_SIZE);
354 	memcpy(sctx->buffer + partial, src, len - done);
355 
356 	return 0;
357 }
358 
359 static int padlock_sha1_final_nano(struct shash_desc *desc, u8 *out)
360 {
361 	struct sha1_state *state = (struct sha1_state *)shash_desc_ctx(desc);
362 	unsigned int partial, padlen;
363 	__be64 bits;
364 	static const u8 padding[64] = { 0x80, };
365 
366 	bits = cpu_to_be64(state->count << 3);
367 
368 	/* Pad out to 56 mod 64 */
369 	partial = state->count & 0x3f;
370 	padlen = (partial < 56) ? (56 - partial) : ((64+56) - partial);
371 	padlock_sha1_update_nano(desc, padding, padlen);
372 
373 	/* Append length field bytes */
374 	padlock_sha1_update_nano(desc, (const u8 *)&bits, sizeof(bits));
375 
376 	/* Swap to output */
377 	padlock_output_block((uint32_t *)(state->state), (uint32_t *)out, 5);
378 
379 	return 0;
380 }
381 
382 static int padlock_sha256_init_nano(struct shash_desc *desc)
383 {
384 	struct sha256_state *sctx = shash_desc_ctx(desc);
385 
386 	*sctx = (struct sha256_state){
387 		.state = { SHA256_H0, SHA256_H1, SHA256_H2, SHA256_H3, \
388 				SHA256_H4, SHA256_H5, SHA256_H6, SHA256_H7},
389 	};
390 
391 	return 0;
392 }
393 
394 static int padlock_sha256_update_nano(struct shash_desc *desc, const u8 *data,
395 			  unsigned int len)
396 {
397 	struct sha256_state *sctx = shash_desc_ctx(desc);
398 	unsigned int partial, done;
399 	const u8 *src;
400 	/*The PHE require the out buffer must 128 bytes and 16-bytes aligned*/
401 	u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
402 		((aligned(STACK_ALIGN)));
403 	u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
404 	int ts_state;
405 
406 	partial = sctx->count & 0x3f;
407 	sctx->count += len;
408 	done = 0;
409 	src = data;
410 	memcpy(dst, (u8 *)(sctx->state), SHA256_DIGEST_SIZE);
411 
412 	if ((partial + len) >= SHA256_BLOCK_SIZE) {
413 
414 		/* Append the bytes in state's buffer to a block to handle */
415 		if (partial) {
416 			done = -partial;
417 			memcpy(sctx->buf + partial, data,
418 				done + SHA256_BLOCK_SIZE);
419 			src = sctx->buf;
420 			ts_state = irq_ts_save();
421 			asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
422 			: "+S"(src), "+D"(dst)
423 			: "a"((long)-1), "c"((unsigned long)1));
424 			irq_ts_restore(ts_state);
425 			done += SHA256_BLOCK_SIZE;
426 			src = data + done;
427 		}
428 
429 		/* Process the left bytes from input data*/
430 		if (len - done >= SHA256_BLOCK_SIZE) {
431 			ts_state = irq_ts_save();
432 			asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
433 			: "+S"(src), "+D"(dst)
434 			: "a"((long)-1),
435 			"c"((unsigned long)((len - done) / 64)));
436 			irq_ts_restore(ts_state);
437 			done += ((len - done) - (len - done) % 64);
438 			src = data + done;
439 		}
440 		partial = 0;
441 	}
442 	memcpy((u8 *)(sctx->state), dst, SHA256_DIGEST_SIZE);
443 	memcpy(sctx->buf + partial, src, len - done);
444 
445 	return 0;
446 }
447 
448 static int padlock_sha256_final_nano(struct shash_desc *desc, u8 *out)
449 {
450 	struct sha256_state *state =
451 		(struct sha256_state *)shash_desc_ctx(desc);
452 	unsigned int partial, padlen;
453 	__be64 bits;
454 	static const u8 padding[64] = { 0x80, };
455 
456 	bits = cpu_to_be64(state->count << 3);
457 
458 	/* Pad out to 56 mod 64 */
459 	partial = state->count & 0x3f;
460 	padlen = (partial < 56) ? (56 - partial) : ((64+56) - partial);
461 	padlock_sha256_update_nano(desc, padding, padlen);
462 
463 	/* Append length field bytes */
464 	padlock_sha256_update_nano(desc, (const u8 *)&bits, sizeof(bits));
465 
466 	/* Swap to output */
467 	padlock_output_block((uint32_t *)(state->state), (uint32_t *)out, 8);
468 
469 	return 0;
470 }
471 
472 static int padlock_sha_export_nano(struct shash_desc *desc,
473 				void *out)
474 {
475 	int statesize = crypto_shash_statesize(desc->tfm);
476 	void *sctx = shash_desc_ctx(desc);
477 
478 	memcpy(out, sctx, statesize);
479 	return 0;
480 }
481 
482 static int padlock_sha_import_nano(struct shash_desc *desc,
483 				const void *in)
484 {
485 	int statesize = crypto_shash_statesize(desc->tfm);
486 	void *sctx = shash_desc_ctx(desc);
487 
488 	memcpy(sctx, in, statesize);
489 	return 0;
490 }
491 
492 static struct shash_alg sha1_alg_nano = {
493 	.digestsize	=	SHA1_DIGEST_SIZE,
494 	.init		=	padlock_sha1_init_nano,
495 	.update		=	padlock_sha1_update_nano,
496 	.final		=	padlock_sha1_final_nano,
497 	.export		=	padlock_sha_export_nano,
498 	.import		=	padlock_sha_import_nano,
499 	.descsize	=	sizeof(struct sha1_state),
500 	.statesize	=	sizeof(struct sha1_state),
501 	.base		=	{
502 		.cra_name		=	"sha1",
503 		.cra_driver_name	=	"sha1-padlock-nano",
504 		.cra_priority		=	PADLOCK_CRA_PRIORITY,
505 		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH,
506 		.cra_blocksize		=	SHA1_BLOCK_SIZE,
507 		.cra_module		=	THIS_MODULE,
508 	}
509 };
510 
511 static struct shash_alg sha256_alg_nano = {
512 	.digestsize	=	SHA256_DIGEST_SIZE,
513 	.init		=	padlock_sha256_init_nano,
514 	.update		=	padlock_sha256_update_nano,
515 	.final		=	padlock_sha256_final_nano,
516 	.export		=	padlock_sha_export_nano,
517 	.import		=	padlock_sha_import_nano,
518 	.descsize	=	sizeof(struct sha256_state),
519 	.statesize	=	sizeof(struct sha256_state),
520 	.base		=	{
521 		.cra_name		=	"sha256",
522 		.cra_driver_name	=	"sha256-padlock-nano",
523 		.cra_priority		=	PADLOCK_CRA_PRIORITY,
524 		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH,
525 		.cra_blocksize		=	SHA256_BLOCK_SIZE,
526 		.cra_module		=	THIS_MODULE,
527 	}
528 };
529 
530 static struct x86_cpu_id padlock_sha_ids[] = {
531 	X86_FEATURE_MATCH(X86_FEATURE_PHE),
532 	{}
533 };
534 MODULE_DEVICE_TABLE(x86cpu, padlock_sha_ids);
535 
536 static int __init padlock_init(void)
537 {
538 	int rc = -ENODEV;
539 	struct cpuinfo_x86 *c = &cpu_data(0);
540 	struct shash_alg *sha1;
541 	struct shash_alg *sha256;
542 
543 	if (!x86_match_cpu(padlock_sha_ids) || !cpu_has_phe_enabled)
544 		return -ENODEV;
545 
546 	/* Register the newly added algorithm module if on *
547 	* VIA Nano processor, or else just do as before */
548 	if (c->x86_model < 0x0f) {
549 		sha1 = &sha1_alg;
550 		sha256 = &sha256_alg;
551 	} else {
552 		sha1 = &sha1_alg_nano;
553 		sha256 = &sha256_alg_nano;
554 	}
555 
556 	rc = crypto_register_shash(sha1);
557 	if (rc)
558 		goto out;
559 
560 	rc = crypto_register_shash(sha256);
561 	if (rc)
562 		goto out_unreg1;
563 
564 	printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
565 
566 	return 0;
567 
568 out_unreg1:
569 	crypto_unregister_shash(sha1);
570 
571 out:
572 	printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
573 	return rc;
574 }
575 
576 static void __exit padlock_fini(void)
577 {
578 	struct cpuinfo_x86 *c = &cpu_data(0);
579 
580 	if (c->x86_model >= 0x0f) {
581 		crypto_unregister_shash(&sha1_alg_nano);
582 		crypto_unregister_shash(&sha256_alg_nano);
583 	} else {
584 		crypto_unregister_shash(&sha1_alg);
585 		crypto_unregister_shash(&sha256_alg);
586 	}
587 }
588 
589 module_init(padlock_init);
590 module_exit(padlock_fini);
591 
592 MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
593 MODULE_LICENSE("GPL");
594 MODULE_AUTHOR("Michal Ludvig");
595 
596 MODULE_ALIAS_CRYPTO("sha1-all");
597 MODULE_ALIAS_CRYPTO("sha256-all");
598 MODULE_ALIAS_CRYPTO("sha1-padlock");
599 MODULE_ALIAS_CRYPTO("sha256-padlock");
600