1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AMD Cryptographic Coprocessor (CCP) SHA crypto API support
4  *
5  * Copyright (C) 2013,2018 Advanced Micro Devices, Inc.
6  *
7  * Author: Tom Lendacky <thomas.lendacky@amd.com>
8  * Author: Gary R Hook <gary.hook@amd.com>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/delay.h>
14 #include <linux/scatterlist.h>
15 #include <linux/crypto.h>
16 #include <crypto/algapi.h>
17 #include <crypto/hash.h>
18 #include <crypto/hmac.h>
19 #include <crypto/internal/hash.h>
20 #include <crypto/sha.h>
21 #include <crypto/scatterwalk.h>
22 #include <linux/string.h>
23 
24 #include "ccp-crypto.h"
25 
26 static int ccp_sha_complete(struct crypto_async_request *async_req, int ret)
27 {
28 	struct ahash_request *req = ahash_request_cast(async_req);
29 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
30 	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
31 	unsigned int digest_size = crypto_ahash_digestsize(tfm);
32 
33 	if (ret)
34 		goto e_free;
35 
36 	if (rctx->hash_rem) {
37 		/* Save remaining data to buffer */
38 		unsigned int offset = rctx->nbytes - rctx->hash_rem;
39 
40 		scatterwalk_map_and_copy(rctx->buf, rctx->src,
41 					 offset, rctx->hash_rem, 0);
42 		rctx->buf_count = rctx->hash_rem;
43 	} else {
44 		rctx->buf_count = 0;
45 	}
46 
47 	/* Update result area if supplied */
48 	if (req->result && rctx->final)
49 		memcpy(req->result, rctx->ctx, digest_size);
50 
51 e_free:
52 	sg_free_table(&rctx->data_sg);
53 
54 	return ret;
55 }
56 
57 static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
58 			     unsigned int final)
59 {
60 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
61 	struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
62 	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
63 	struct scatterlist *sg;
64 	unsigned int block_size =
65 		crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
66 	unsigned int sg_count;
67 	gfp_t gfp;
68 	u64 len;
69 	int ret;
70 
71 	len = (u64)rctx->buf_count + (u64)nbytes;
72 
73 	if (!final && (len <= block_size)) {
74 		scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src,
75 					 0, nbytes, 0);
76 		rctx->buf_count += nbytes;
77 
78 		return 0;
79 	}
80 
81 	rctx->src = req->src;
82 	rctx->nbytes = nbytes;
83 
84 	rctx->final = final;
85 	rctx->hash_rem = final ? 0 : len & (block_size - 1);
86 	rctx->hash_cnt = len - rctx->hash_rem;
87 	if (!final && !rctx->hash_rem) {
88 		/* CCP can't do zero length final, so keep some data around */
89 		rctx->hash_cnt -= block_size;
90 		rctx->hash_rem = block_size;
91 	}
92 
93 	/* Initialize the context scatterlist */
94 	sg_init_one(&rctx->ctx_sg, rctx->ctx, sizeof(rctx->ctx));
95 
96 	sg = NULL;
97 	if (rctx->buf_count && nbytes) {
98 		/* Build the data scatterlist table - allocate enough entries
99 		 * for both data pieces (buffer and input data)
100 		 */
101 		gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
102 			GFP_KERNEL : GFP_ATOMIC;
103 		sg_count = sg_nents(req->src) + 1;
104 		ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp);
105 		if (ret)
106 			return ret;
107 
108 		sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
109 		sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg);
110 		if (!sg) {
111 			ret = -EINVAL;
112 			goto e_free;
113 		}
114 		sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src);
115 		if (!sg) {
116 			ret = -EINVAL;
117 			goto e_free;
118 		}
119 		sg_mark_end(sg);
120 
121 		sg = rctx->data_sg.sgl;
122 	} else if (rctx->buf_count) {
123 		sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
124 
125 		sg = &rctx->buf_sg;
126 	} else if (nbytes) {
127 		sg = req->src;
128 	}
129 
130 	rctx->msg_bits += (rctx->hash_cnt << 3);	/* Total in bits */
131 
132 	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
133 	INIT_LIST_HEAD(&rctx->cmd.entry);
134 	rctx->cmd.engine = CCP_ENGINE_SHA;
135 	rctx->cmd.u.sha.type = rctx->type;
136 	rctx->cmd.u.sha.ctx = &rctx->ctx_sg;
137 
138 	switch (rctx->type) {
139 	case CCP_SHA_TYPE_1:
140 		rctx->cmd.u.sha.ctx_len = SHA1_DIGEST_SIZE;
141 		break;
142 	case CCP_SHA_TYPE_224:
143 		rctx->cmd.u.sha.ctx_len = SHA224_DIGEST_SIZE;
144 		break;
145 	case CCP_SHA_TYPE_256:
146 		rctx->cmd.u.sha.ctx_len = SHA256_DIGEST_SIZE;
147 		break;
148 	case CCP_SHA_TYPE_384:
149 		rctx->cmd.u.sha.ctx_len = SHA384_DIGEST_SIZE;
150 		break;
151 	case CCP_SHA_TYPE_512:
152 		rctx->cmd.u.sha.ctx_len = SHA512_DIGEST_SIZE;
153 		break;
154 	default:
155 		/* Should never get here */
156 		break;
157 	}
158 
159 	rctx->cmd.u.sha.src = sg;
160 	rctx->cmd.u.sha.src_len = rctx->hash_cnt;
161 	rctx->cmd.u.sha.opad = ctx->u.sha.key_len ?
162 		&ctx->u.sha.opad_sg : NULL;
163 	rctx->cmd.u.sha.opad_len = ctx->u.sha.key_len ?
164 		ctx->u.sha.opad_count : 0;
165 	rctx->cmd.u.sha.first = rctx->first;
166 	rctx->cmd.u.sha.final = rctx->final;
167 	rctx->cmd.u.sha.msg_bits = rctx->msg_bits;
168 
169 	rctx->first = 0;
170 
171 	ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
172 
173 	return ret;
174 
175 e_free:
176 	sg_free_table(&rctx->data_sg);
177 
178 	return ret;
179 }
180 
181 static int ccp_sha_init(struct ahash_request *req)
182 {
183 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
184 	struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
185 	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
186 	struct ccp_crypto_ahash_alg *alg =
187 		ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm));
188 	unsigned int block_size =
189 		crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
190 
191 	memset(rctx, 0, sizeof(*rctx));
192 
193 	rctx->type = alg->type;
194 	rctx->first = 1;
195 
196 	if (ctx->u.sha.key_len) {
197 		/* Buffer the HMAC key for first update */
198 		memcpy(rctx->buf, ctx->u.sha.ipad, block_size);
199 		rctx->buf_count = block_size;
200 	}
201 
202 	return 0;
203 }
204 
205 static int ccp_sha_update(struct ahash_request *req)
206 {
207 	return ccp_do_sha_update(req, req->nbytes, 0);
208 }
209 
210 static int ccp_sha_final(struct ahash_request *req)
211 {
212 	return ccp_do_sha_update(req, 0, 1);
213 }
214 
215 static int ccp_sha_finup(struct ahash_request *req)
216 {
217 	return ccp_do_sha_update(req, req->nbytes, 1);
218 }
219 
220 static int ccp_sha_digest(struct ahash_request *req)
221 {
222 	int ret;
223 
224 	ret = ccp_sha_init(req);
225 	if (ret)
226 		return ret;
227 
228 	return ccp_sha_finup(req);
229 }
230 
231 static int ccp_sha_export(struct ahash_request *req, void *out)
232 {
233 	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
234 	struct ccp_sha_exp_ctx state;
235 
236 	/* Don't let anything leak to 'out' */
237 	memset(&state, 0, sizeof(state));
238 
239 	state.type = rctx->type;
240 	state.msg_bits = rctx->msg_bits;
241 	state.first = rctx->first;
242 	memcpy(state.ctx, rctx->ctx, sizeof(state.ctx));
243 	state.buf_count = rctx->buf_count;
244 	memcpy(state.buf, rctx->buf, sizeof(state.buf));
245 
246 	/* 'out' may not be aligned so memcpy from local variable */
247 	memcpy(out, &state, sizeof(state));
248 
249 	return 0;
250 }
251 
252 static int ccp_sha_import(struct ahash_request *req, const void *in)
253 {
254 	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
255 	struct ccp_sha_exp_ctx state;
256 
257 	/* 'in' may not be aligned so memcpy to local variable */
258 	memcpy(&state, in, sizeof(state));
259 
260 	memset(rctx, 0, sizeof(*rctx));
261 	rctx->type = state.type;
262 	rctx->msg_bits = state.msg_bits;
263 	rctx->first = state.first;
264 	memcpy(rctx->ctx, state.ctx, sizeof(rctx->ctx));
265 	rctx->buf_count = state.buf_count;
266 	memcpy(rctx->buf, state.buf, sizeof(rctx->buf));
267 
268 	return 0;
269 }
270 
271 static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
272 			  unsigned int key_len)
273 {
274 	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
275 	struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
276 	unsigned int block_size = crypto_shash_blocksize(shash);
277 	unsigned int digest_size = crypto_shash_digestsize(shash);
278 	int i, ret;
279 
280 	/* Set to zero until complete */
281 	ctx->u.sha.key_len = 0;
282 
283 	/* Clear key area to provide zero padding for keys smaller
284 	 * than the block size
285 	 */
286 	memset(ctx->u.sha.key, 0, sizeof(ctx->u.sha.key));
287 
288 	if (key_len > block_size) {
289 		/* Must hash the input key */
290 		ret = crypto_shash_tfm_digest(shash, key, key_len,
291 					      ctx->u.sha.key);
292 		if (ret)
293 			return -EINVAL;
294 
295 		key_len = digest_size;
296 	} else {
297 		memcpy(ctx->u.sha.key, key, key_len);
298 	}
299 
300 	for (i = 0; i < block_size; i++) {
301 		ctx->u.sha.ipad[i] = ctx->u.sha.key[i] ^ HMAC_IPAD_VALUE;
302 		ctx->u.sha.opad[i] = ctx->u.sha.key[i] ^ HMAC_OPAD_VALUE;
303 	}
304 
305 	sg_init_one(&ctx->u.sha.opad_sg, ctx->u.sha.opad, block_size);
306 	ctx->u.sha.opad_count = block_size;
307 
308 	ctx->u.sha.key_len = key_len;
309 
310 	return 0;
311 }
312 
313 static int ccp_sha_cra_init(struct crypto_tfm *tfm)
314 {
315 	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
316 	struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);
317 
318 	ctx->complete = ccp_sha_complete;
319 	ctx->u.sha.key_len = 0;
320 
321 	crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_sha_req_ctx));
322 
323 	return 0;
324 }
325 
326 static void ccp_sha_cra_exit(struct crypto_tfm *tfm)
327 {
328 }
329 
330 static int ccp_hmac_sha_cra_init(struct crypto_tfm *tfm)
331 {
332 	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
333 	struct ccp_crypto_ahash_alg *alg = ccp_crypto_ahash_alg(tfm);
334 	struct crypto_shash *hmac_tfm;
335 
336 	hmac_tfm = crypto_alloc_shash(alg->child_alg, 0, 0);
337 	if (IS_ERR(hmac_tfm)) {
338 		pr_warn("could not load driver %s need for HMAC support\n",
339 			alg->child_alg);
340 		return PTR_ERR(hmac_tfm);
341 	}
342 
343 	ctx->u.sha.hmac_tfm = hmac_tfm;
344 
345 	return ccp_sha_cra_init(tfm);
346 }
347 
348 static void ccp_hmac_sha_cra_exit(struct crypto_tfm *tfm)
349 {
350 	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
351 
352 	if (ctx->u.sha.hmac_tfm)
353 		crypto_free_shash(ctx->u.sha.hmac_tfm);
354 
355 	ccp_sha_cra_exit(tfm);
356 }
357 
358 struct ccp_sha_def {
359 	unsigned int version;
360 	const char *name;
361 	const char *drv_name;
362 	enum ccp_sha_type type;
363 	u32 digest_size;
364 	u32 block_size;
365 };
366 
367 static struct ccp_sha_def sha_algs[] = {
368 	{
369 		.version	= CCP_VERSION(3, 0),
370 		.name		= "sha1",
371 		.drv_name	= "sha1-ccp",
372 		.type		= CCP_SHA_TYPE_1,
373 		.digest_size	= SHA1_DIGEST_SIZE,
374 		.block_size	= SHA1_BLOCK_SIZE,
375 	},
376 	{
377 		.version	= CCP_VERSION(3, 0),
378 		.name		= "sha224",
379 		.drv_name	= "sha224-ccp",
380 		.type		= CCP_SHA_TYPE_224,
381 		.digest_size	= SHA224_DIGEST_SIZE,
382 		.block_size	= SHA224_BLOCK_SIZE,
383 	},
384 	{
385 		.version	= CCP_VERSION(3, 0),
386 		.name		= "sha256",
387 		.drv_name	= "sha256-ccp",
388 		.type		= CCP_SHA_TYPE_256,
389 		.digest_size	= SHA256_DIGEST_SIZE,
390 		.block_size	= SHA256_BLOCK_SIZE,
391 	},
392 	{
393 		.version	= CCP_VERSION(5, 0),
394 		.name		= "sha384",
395 		.drv_name	= "sha384-ccp",
396 		.type		= CCP_SHA_TYPE_384,
397 		.digest_size	= SHA384_DIGEST_SIZE,
398 		.block_size	= SHA384_BLOCK_SIZE,
399 	},
400 	{
401 		.version	= CCP_VERSION(5, 0),
402 		.name		= "sha512",
403 		.drv_name	= "sha512-ccp",
404 		.type		= CCP_SHA_TYPE_512,
405 		.digest_size	= SHA512_DIGEST_SIZE,
406 		.block_size	= SHA512_BLOCK_SIZE,
407 	},
408 };
409 
410 static int ccp_register_hmac_alg(struct list_head *head,
411 				 const struct ccp_sha_def *def,
412 				 const struct ccp_crypto_ahash_alg *base_alg)
413 {
414 	struct ccp_crypto_ahash_alg *ccp_alg;
415 	struct ahash_alg *alg;
416 	struct hash_alg_common *halg;
417 	struct crypto_alg *base;
418 	int ret;
419 
420 	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
421 	if (!ccp_alg)
422 		return -ENOMEM;
423 
424 	/* Copy the base algorithm and only change what's necessary */
425 	*ccp_alg = *base_alg;
426 	INIT_LIST_HEAD(&ccp_alg->entry);
427 
428 	strscpy(ccp_alg->child_alg, def->name, CRYPTO_MAX_ALG_NAME);
429 
430 	alg = &ccp_alg->alg;
431 	alg->setkey = ccp_sha_setkey;
432 
433 	halg = &alg->halg;
434 
435 	base = &halg->base;
436 	snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", def->name);
437 	snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "hmac-%s",
438 		 def->drv_name);
439 	base->cra_init = ccp_hmac_sha_cra_init;
440 	base->cra_exit = ccp_hmac_sha_cra_exit;
441 
442 	ret = crypto_register_ahash(alg);
443 	if (ret) {
444 		pr_err("%s ahash algorithm registration error (%d)\n",
445 		       base->cra_name, ret);
446 		kfree(ccp_alg);
447 		return ret;
448 	}
449 
450 	list_add(&ccp_alg->entry, head);
451 
452 	return ret;
453 }
454 
455 static int ccp_register_sha_alg(struct list_head *head,
456 				const struct ccp_sha_def *def)
457 {
458 	struct ccp_crypto_ahash_alg *ccp_alg;
459 	struct ahash_alg *alg;
460 	struct hash_alg_common *halg;
461 	struct crypto_alg *base;
462 	int ret;
463 
464 	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
465 	if (!ccp_alg)
466 		return -ENOMEM;
467 
468 	INIT_LIST_HEAD(&ccp_alg->entry);
469 
470 	ccp_alg->type = def->type;
471 
472 	alg = &ccp_alg->alg;
473 	alg->init = ccp_sha_init;
474 	alg->update = ccp_sha_update;
475 	alg->final = ccp_sha_final;
476 	alg->finup = ccp_sha_finup;
477 	alg->digest = ccp_sha_digest;
478 	alg->export = ccp_sha_export;
479 	alg->import = ccp_sha_import;
480 
481 	halg = &alg->halg;
482 	halg->digestsize = def->digest_size;
483 	halg->statesize = sizeof(struct ccp_sha_exp_ctx);
484 
485 	base = &halg->base;
486 	snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
487 	snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
488 		 def->drv_name);
489 	base->cra_flags = CRYPTO_ALG_ASYNC |
490 			  CRYPTO_ALG_ALLOCATES_MEMORY |
491 			  CRYPTO_ALG_KERN_DRIVER_ONLY |
492 			  CRYPTO_ALG_NEED_FALLBACK;
493 	base->cra_blocksize = def->block_size;
494 	base->cra_ctxsize = sizeof(struct ccp_ctx);
495 	base->cra_priority = CCP_CRA_PRIORITY;
496 	base->cra_init = ccp_sha_cra_init;
497 	base->cra_exit = ccp_sha_cra_exit;
498 	base->cra_module = THIS_MODULE;
499 
500 	ret = crypto_register_ahash(alg);
501 	if (ret) {
502 		pr_err("%s ahash algorithm registration error (%d)\n",
503 		       base->cra_name, ret);
504 		kfree(ccp_alg);
505 		return ret;
506 	}
507 
508 	list_add(&ccp_alg->entry, head);
509 
510 	ret = ccp_register_hmac_alg(head, def, ccp_alg);
511 
512 	return ret;
513 }
514 
515 int ccp_register_sha_algs(struct list_head *head)
516 {
517 	int i, ret;
518 	unsigned int ccpversion = ccp_version();
519 
520 	for (i = 0; i < ARRAY_SIZE(sha_algs); i++) {
521 		if (sha_algs[i].version > ccpversion)
522 			continue;
523 		ret = ccp_register_sha_alg(head, &sha_algs[i]);
524 		if (ret)
525 			return ret;
526 	}
527 
528 	return 0;
529 }
530