xref: /openbmc/linux/drivers/crypto/padlock-sha.c (revision 20e2fc42)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Cryptographic API.
4  *
5  * Support for VIA PadLock hardware crypto engine.
6  *
7  * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
8  */
9 
10 #include <crypto/internal/hash.h>
11 #include <crypto/padlock.h>
12 #include <crypto/sha.h>
13 #include <linux/err.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/errno.h>
17 #include <linux/interrupt.h>
18 #include <linux/kernel.h>
19 #include <linux/scatterlist.h>
20 #include <asm/cpu_device_id.h>
21 #include <asm/fpu/api.h>
22 
23 struct padlock_sha_desc {
24 	struct shash_desc fallback;
25 };
26 
27 struct padlock_sha_ctx {
28 	struct crypto_shash *fallback;
29 };
30 
31 static int padlock_sha_init(struct shash_desc *desc)
32 {
33 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
34 	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
35 
36 	dctx->fallback.tfm = ctx->fallback;
37 	return crypto_shash_init(&dctx->fallback);
38 }
39 
40 static int padlock_sha_update(struct shash_desc *desc,
41 			      const u8 *data, unsigned int length)
42 {
43 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
44 
45 	return crypto_shash_update(&dctx->fallback, data, length);
46 }
47 
48 static int padlock_sha_export(struct shash_desc *desc, void *out)
49 {
50 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
51 
52 	return crypto_shash_export(&dctx->fallback, out);
53 }
54 
55 static int padlock_sha_import(struct shash_desc *desc, const void *in)
56 {
57 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
58 	struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
59 
60 	dctx->fallback.tfm = ctx->fallback;
61 	return crypto_shash_import(&dctx->fallback, in);
62 }
63 
64 static inline void padlock_output_block(uint32_t *src,
65 		 	uint32_t *dst, size_t count)
66 {
67 	while (count--)
68 		*dst++ = swab32(*src++);
69 }
70 
71 static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
72 			      unsigned int count, u8 *out)
73 {
74 	/* We can't store directly to *out as it may be unaligned. */
75 	/* BTW Don't reduce the buffer size below 128 Bytes!
76 	 *     PadLock microcode needs it that big. */
77 	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
78 		((aligned(STACK_ALIGN)));
79 	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
80 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
81 	struct sha1_state state;
82 	unsigned int space;
83 	unsigned int leftover;
84 	int err;
85 
86 	err = crypto_shash_export(&dctx->fallback, &state);
87 	if (err)
88 		goto out;
89 
90 	if (state.count + count > ULONG_MAX)
91 		return crypto_shash_finup(&dctx->fallback, in, count, out);
92 
93 	leftover = ((state.count - 1) & (SHA1_BLOCK_SIZE - 1)) + 1;
94 	space =  SHA1_BLOCK_SIZE - leftover;
95 	if (space) {
96 		if (count > space) {
97 			err = crypto_shash_update(&dctx->fallback, in, space) ?:
98 			      crypto_shash_export(&dctx->fallback, &state);
99 			if (err)
100 				goto out;
101 			count -= space;
102 			in += space;
103 		} else {
104 			memcpy(state.buffer + leftover, in, count);
105 			in = state.buffer;
106 			count += leftover;
107 			state.count &= ~(SHA1_BLOCK_SIZE - 1);
108 		}
109 	}
110 
111 	memcpy(result, &state.state, SHA1_DIGEST_SIZE);
112 
113 	asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
114 		      : \
115 		      : "c"((unsigned long)state.count + count), \
116 			"a"((unsigned long)state.count), \
117 			"S"(in), "D"(result));
118 
119 	padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
120 
121 out:
122 	return err;
123 }
124 
125 static int padlock_sha1_final(struct shash_desc *desc, u8 *out)
126 {
127 	u8 buf[4];
128 
129 	return padlock_sha1_finup(desc, buf, 0, out);
130 }
131 
132 static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
133 				unsigned int count, u8 *out)
134 {
135 	/* We can't store directly to *out as it may be unaligned. */
136 	/* BTW Don't reduce the buffer size below 128 Bytes!
137 	 *     PadLock microcode needs it that big. */
138 	char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
139 		((aligned(STACK_ALIGN)));
140 	char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
141 	struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
142 	struct sha256_state state;
143 	unsigned int space;
144 	unsigned int leftover;
145 	int err;
146 
147 	err = crypto_shash_export(&dctx->fallback, &state);
148 	if (err)
149 		goto out;
150 
151 	if (state.count + count > ULONG_MAX)
152 		return crypto_shash_finup(&dctx->fallback, in, count, out);
153 
154 	leftover = ((state.count - 1) & (SHA256_BLOCK_SIZE - 1)) + 1;
155 	space =  SHA256_BLOCK_SIZE - leftover;
156 	if (space) {
157 		if (count > space) {
158 			err = crypto_shash_update(&dctx->fallback, in, space) ?:
159 			      crypto_shash_export(&dctx->fallback, &state);
160 			if (err)
161 				goto out;
162 			count -= space;
163 			in += space;
164 		} else {
165 			memcpy(state.buf + leftover, in, count);
166 			in = state.buf;
167 			count += leftover;
168 			state.count &= ~(SHA1_BLOCK_SIZE - 1);
169 		}
170 	}
171 
172 	memcpy(result, &state.state, SHA256_DIGEST_SIZE);
173 
174 	asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
175 		      : \
176 		      : "c"((unsigned long)state.count + count), \
177 			"a"((unsigned long)state.count), \
178 			"S"(in), "D"(result));
179 
180 	padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
181 
182 out:
183 	return err;
184 }
185 
186 static int padlock_sha256_final(struct shash_desc *desc, u8 *out)
187 {
188 	u8 buf[4];
189 
190 	return padlock_sha256_finup(desc, buf, 0, out);
191 }
192 
193 static int padlock_cra_init(struct crypto_tfm *tfm)
194 {
195 	struct crypto_shash *hash = __crypto_shash_cast(tfm);
196 	const char *fallback_driver_name = crypto_tfm_alg_name(tfm);
197 	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
198 	struct crypto_shash *fallback_tfm;
199 	int err = -ENOMEM;
200 
201 	/* Allocate a fallback and abort if it failed. */
202 	fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
203 					  CRYPTO_ALG_NEED_FALLBACK);
204 	if (IS_ERR(fallback_tfm)) {
205 		printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
206 		       fallback_driver_name);
207 		err = PTR_ERR(fallback_tfm);
208 		goto out;
209 	}
210 
211 	ctx->fallback = fallback_tfm;
212 	hash->descsize += crypto_shash_descsize(fallback_tfm);
213 	return 0;
214 
215 out:
216 	return err;
217 }
218 
219 static void padlock_cra_exit(struct crypto_tfm *tfm)
220 {
221 	struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
222 
223 	crypto_free_shash(ctx->fallback);
224 }
225 
226 static struct shash_alg sha1_alg = {
227 	.digestsize	=	SHA1_DIGEST_SIZE,
228 	.init   	= 	padlock_sha_init,
229 	.update 	=	padlock_sha_update,
230 	.finup  	=	padlock_sha1_finup,
231 	.final  	=	padlock_sha1_final,
232 	.export		=	padlock_sha_export,
233 	.import		=	padlock_sha_import,
234 	.descsize	=	sizeof(struct padlock_sha_desc),
235 	.statesize	=	sizeof(struct sha1_state),
236 	.base		=	{
237 		.cra_name		=	"sha1",
238 		.cra_driver_name	=	"sha1-padlock",
239 		.cra_priority		=	PADLOCK_CRA_PRIORITY,
240 		.cra_flags		=	CRYPTO_ALG_NEED_FALLBACK,
241 		.cra_blocksize		=	SHA1_BLOCK_SIZE,
242 		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
243 		.cra_module		=	THIS_MODULE,
244 		.cra_init		=	padlock_cra_init,
245 		.cra_exit		=	padlock_cra_exit,
246 	}
247 };
248 
249 static struct shash_alg sha256_alg = {
250 	.digestsize	=	SHA256_DIGEST_SIZE,
251 	.init   	= 	padlock_sha_init,
252 	.update 	=	padlock_sha_update,
253 	.finup  	=	padlock_sha256_finup,
254 	.final  	=	padlock_sha256_final,
255 	.export		=	padlock_sha_export,
256 	.import		=	padlock_sha_import,
257 	.descsize	=	sizeof(struct padlock_sha_desc),
258 	.statesize	=	sizeof(struct sha256_state),
259 	.base		=	{
260 		.cra_name		=	"sha256",
261 		.cra_driver_name	=	"sha256-padlock",
262 		.cra_priority		=	PADLOCK_CRA_PRIORITY,
263 		.cra_flags		=	CRYPTO_ALG_NEED_FALLBACK,
264 		.cra_blocksize		=	SHA256_BLOCK_SIZE,
265 		.cra_ctxsize		=	sizeof(struct padlock_sha_ctx),
266 		.cra_module		=	THIS_MODULE,
267 		.cra_init		=	padlock_cra_init,
268 		.cra_exit		=	padlock_cra_exit,
269 	}
270 };
271 
272 /* Add two shash_alg instance for hardware-implemented *
273 * multiple-parts hash supported by VIA Nano Processor.*/
274 static int padlock_sha1_init_nano(struct shash_desc *desc)
275 {
276 	struct sha1_state *sctx = shash_desc_ctx(desc);
277 
278 	*sctx = (struct sha1_state){
279 		.state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
280 	};
281 
282 	return 0;
283 }
284 
285 static int padlock_sha1_update_nano(struct shash_desc *desc,
286 			const u8 *data,	unsigned int len)
287 {
288 	struct sha1_state *sctx = shash_desc_ctx(desc);
289 	unsigned int partial, done;
290 	const u8 *src;
291 	/*The PHE require the out buffer must 128 bytes and 16-bytes aligned*/
292 	u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
293 		((aligned(STACK_ALIGN)));
294 	u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
295 
296 	partial = sctx->count & 0x3f;
297 	sctx->count += len;
298 	done = 0;
299 	src = data;
300 	memcpy(dst, (u8 *)(sctx->state), SHA1_DIGEST_SIZE);
301 
302 	if ((partial + len) >= SHA1_BLOCK_SIZE) {
303 
304 		/* Append the bytes in state's buffer to a block to handle */
305 		if (partial) {
306 			done = -partial;
307 			memcpy(sctx->buffer + partial, data,
308 				done + SHA1_BLOCK_SIZE);
309 			src = sctx->buffer;
310 			asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
311 			: "+S"(src), "+D"(dst) \
312 			: "a"((long)-1), "c"((unsigned long)1));
313 			done += SHA1_BLOCK_SIZE;
314 			src = data + done;
315 		}
316 
317 		/* Process the left bytes from the input data */
318 		if (len - done >= SHA1_BLOCK_SIZE) {
319 			asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
320 			: "+S"(src), "+D"(dst)
321 			: "a"((long)-1),
322 			"c"((unsigned long)((len - done) / SHA1_BLOCK_SIZE)));
323 			done += ((len - done) - (len - done) % SHA1_BLOCK_SIZE);
324 			src = data + done;
325 		}
326 		partial = 0;
327 	}
328 	memcpy((u8 *)(sctx->state), dst, SHA1_DIGEST_SIZE);
329 	memcpy(sctx->buffer + partial, src, len - done);
330 
331 	return 0;
332 }
333 
334 static int padlock_sha1_final_nano(struct shash_desc *desc, u8 *out)
335 {
336 	struct sha1_state *state = (struct sha1_state *)shash_desc_ctx(desc);
337 	unsigned int partial, padlen;
338 	__be64 bits;
339 	static const u8 padding[64] = { 0x80, };
340 
341 	bits = cpu_to_be64(state->count << 3);
342 
343 	/* Pad out to 56 mod 64 */
344 	partial = state->count & 0x3f;
345 	padlen = (partial < 56) ? (56 - partial) : ((64+56) - partial);
346 	padlock_sha1_update_nano(desc, padding, padlen);
347 
348 	/* Append length field bytes */
349 	padlock_sha1_update_nano(desc, (const u8 *)&bits, sizeof(bits));
350 
351 	/* Swap to output */
352 	padlock_output_block((uint32_t *)(state->state), (uint32_t *)out, 5);
353 
354 	return 0;
355 }
356 
357 static int padlock_sha256_init_nano(struct shash_desc *desc)
358 {
359 	struct sha256_state *sctx = shash_desc_ctx(desc);
360 
361 	*sctx = (struct sha256_state){
362 		.state = { SHA256_H0, SHA256_H1, SHA256_H2, SHA256_H3, \
363 				SHA256_H4, SHA256_H5, SHA256_H6, SHA256_H7},
364 	};
365 
366 	return 0;
367 }
368 
369 static int padlock_sha256_update_nano(struct shash_desc *desc, const u8 *data,
370 			  unsigned int len)
371 {
372 	struct sha256_state *sctx = shash_desc_ctx(desc);
373 	unsigned int partial, done;
374 	const u8 *src;
375 	/*The PHE require the out buffer must 128 bytes and 16-bytes aligned*/
376 	u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
377 		((aligned(STACK_ALIGN)));
378 	u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
379 
380 	partial = sctx->count & 0x3f;
381 	sctx->count += len;
382 	done = 0;
383 	src = data;
384 	memcpy(dst, (u8 *)(sctx->state), SHA256_DIGEST_SIZE);
385 
386 	if ((partial + len) >= SHA256_BLOCK_SIZE) {
387 
388 		/* Append the bytes in state's buffer to a block to handle */
389 		if (partial) {
390 			done = -partial;
391 			memcpy(sctx->buf + partial, data,
392 				done + SHA256_BLOCK_SIZE);
393 			src = sctx->buf;
394 			asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
395 			: "+S"(src), "+D"(dst)
396 			: "a"((long)-1), "c"((unsigned long)1));
397 			done += SHA256_BLOCK_SIZE;
398 			src = data + done;
399 		}
400 
401 		/* Process the left bytes from input data*/
402 		if (len - done >= SHA256_BLOCK_SIZE) {
403 			asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
404 			: "+S"(src), "+D"(dst)
405 			: "a"((long)-1),
406 			"c"((unsigned long)((len - done) / 64)));
407 			done += ((len - done) - (len - done) % 64);
408 			src = data + done;
409 		}
410 		partial = 0;
411 	}
412 	memcpy((u8 *)(sctx->state), dst, SHA256_DIGEST_SIZE);
413 	memcpy(sctx->buf + partial, src, len - done);
414 
415 	return 0;
416 }
417 
418 static int padlock_sha256_final_nano(struct shash_desc *desc, u8 *out)
419 {
420 	struct sha256_state *state =
421 		(struct sha256_state *)shash_desc_ctx(desc);
422 	unsigned int partial, padlen;
423 	__be64 bits;
424 	static const u8 padding[64] = { 0x80, };
425 
426 	bits = cpu_to_be64(state->count << 3);
427 
428 	/* Pad out to 56 mod 64 */
429 	partial = state->count & 0x3f;
430 	padlen = (partial < 56) ? (56 - partial) : ((64+56) - partial);
431 	padlock_sha256_update_nano(desc, padding, padlen);
432 
433 	/* Append length field bytes */
434 	padlock_sha256_update_nano(desc, (const u8 *)&bits, sizeof(bits));
435 
436 	/* Swap to output */
437 	padlock_output_block((uint32_t *)(state->state), (uint32_t *)out, 8);
438 
439 	return 0;
440 }
441 
442 static int padlock_sha_export_nano(struct shash_desc *desc,
443 				void *out)
444 {
445 	int statesize = crypto_shash_statesize(desc->tfm);
446 	void *sctx = shash_desc_ctx(desc);
447 
448 	memcpy(out, sctx, statesize);
449 	return 0;
450 }
451 
452 static int padlock_sha_import_nano(struct shash_desc *desc,
453 				const void *in)
454 {
455 	int statesize = crypto_shash_statesize(desc->tfm);
456 	void *sctx = shash_desc_ctx(desc);
457 
458 	memcpy(sctx, in, statesize);
459 	return 0;
460 }
461 
462 static struct shash_alg sha1_alg_nano = {
463 	.digestsize	=	SHA1_DIGEST_SIZE,
464 	.init		=	padlock_sha1_init_nano,
465 	.update		=	padlock_sha1_update_nano,
466 	.final		=	padlock_sha1_final_nano,
467 	.export		=	padlock_sha_export_nano,
468 	.import		=	padlock_sha_import_nano,
469 	.descsize	=	sizeof(struct sha1_state),
470 	.statesize	=	sizeof(struct sha1_state),
471 	.base		=	{
472 		.cra_name		=	"sha1",
473 		.cra_driver_name	=	"sha1-padlock-nano",
474 		.cra_priority		=	PADLOCK_CRA_PRIORITY,
475 		.cra_blocksize		=	SHA1_BLOCK_SIZE,
476 		.cra_module		=	THIS_MODULE,
477 	}
478 };
479 
480 static struct shash_alg sha256_alg_nano = {
481 	.digestsize	=	SHA256_DIGEST_SIZE,
482 	.init		=	padlock_sha256_init_nano,
483 	.update		=	padlock_sha256_update_nano,
484 	.final		=	padlock_sha256_final_nano,
485 	.export		=	padlock_sha_export_nano,
486 	.import		=	padlock_sha_import_nano,
487 	.descsize	=	sizeof(struct sha256_state),
488 	.statesize	=	sizeof(struct sha256_state),
489 	.base		=	{
490 		.cra_name		=	"sha256",
491 		.cra_driver_name	=	"sha256-padlock-nano",
492 		.cra_priority		=	PADLOCK_CRA_PRIORITY,
493 		.cra_blocksize		=	SHA256_BLOCK_SIZE,
494 		.cra_module		=	THIS_MODULE,
495 	}
496 };
497 
498 static const struct x86_cpu_id padlock_sha_ids[] = {
499 	X86_FEATURE_MATCH(X86_FEATURE_PHE),
500 	{}
501 };
502 MODULE_DEVICE_TABLE(x86cpu, padlock_sha_ids);
503 
504 static int __init padlock_init(void)
505 {
506 	int rc = -ENODEV;
507 	struct cpuinfo_x86 *c = &cpu_data(0);
508 	struct shash_alg *sha1;
509 	struct shash_alg *sha256;
510 
511 	if (!x86_match_cpu(padlock_sha_ids) || !boot_cpu_has(X86_FEATURE_PHE_EN))
512 		return -ENODEV;
513 
514 	/* Register the newly added algorithm module if on *
515 	* VIA Nano processor, or else just do as before */
516 	if (c->x86_model < 0x0f) {
517 		sha1 = &sha1_alg;
518 		sha256 = &sha256_alg;
519 	} else {
520 		sha1 = &sha1_alg_nano;
521 		sha256 = &sha256_alg_nano;
522 	}
523 
524 	rc = crypto_register_shash(sha1);
525 	if (rc)
526 		goto out;
527 
528 	rc = crypto_register_shash(sha256);
529 	if (rc)
530 		goto out_unreg1;
531 
532 	printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
533 
534 	return 0;
535 
536 out_unreg1:
537 	crypto_unregister_shash(sha1);
538 
539 out:
540 	printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
541 	return rc;
542 }
543 
544 static void __exit padlock_fini(void)
545 {
546 	struct cpuinfo_x86 *c = &cpu_data(0);
547 
548 	if (c->x86_model >= 0x0f) {
549 		crypto_unregister_shash(&sha1_alg_nano);
550 		crypto_unregister_shash(&sha256_alg_nano);
551 	} else {
552 		crypto_unregister_shash(&sha1_alg);
553 		crypto_unregister_shash(&sha256_alg);
554 	}
555 }
556 
557 module_init(padlock_init);
558 module_exit(padlock_fini);
559 
560 MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
561 MODULE_LICENSE("GPL");
562 MODULE_AUTHOR("Michal Ludvig");
563 
564 MODULE_ALIAS_CRYPTO("sha1-all");
565 MODULE_ALIAS_CRYPTO("sha256-all");
566 MODULE_ALIAS_CRYPTO("sha1-padlock");
567 MODULE_ALIAS_CRYPTO("sha256-padlock");
568