xref: /linux/drivers/crypto/qce/skcipher.c (revision aec2f682d47c54ef434b2d440992626d80b1ebdc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
4  */
5 
6 #include <linux/device.h>
7 #include <linux/dma-mapping.h>
8 #include <linux/interrupt.h>
9 #include <linux/moduleparam.h>
10 #include <linux/string.h>
11 #include <linux/types.h>
12 #include <linux/errno.h>
13 #include <crypto/aes.h>
14 #include <crypto/internal/des.h>
15 #include <crypto/internal/skcipher.h>
16 
17 #include "cipher.h"
18 
19 static unsigned int aes_sw_max_len = CONFIG_CRYPTO_DEV_QCE_SW_MAX_LEN;
20 module_param(aes_sw_max_len, uint, 0644);
21 MODULE_PARM_DESC(aes_sw_max_len,
22 		 "Only use hardware for AES requests larger than this "
23 		 "[0=always use hardware; anything <16 breaks AES-GCM; default="
24 		 __stringify(CONFIG_CRYPTO_DEV_QCE_SW_MAX_LEN)"]");
25 
26 static LIST_HEAD(skcipher_algs);
27 
qce_skcipher_done(void * data)28 static void qce_skcipher_done(void *data)
29 {
30 	struct crypto_async_request *async_req = data;
31 	struct skcipher_request *req = skcipher_request_cast(async_req);
32 	struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
33 	struct qce_alg_template *tmpl = to_cipher_tmpl(crypto_skcipher_reqtfm(req));
34 	struct qce_device *qce = tmpl->qce;
35 	struct qce_result_dump *result_buf = qce->dma.result_buf;
36 	enum dma_data_direction dir_src, dir_dst;
37 	u32 status;
38 	int error;
39 	bool diff_dst;
40 
41 	diff_dst = (req->src != req->dst) ? true : false;
42 	dir_src = diff_dst ? DMA_TO_DEVICE : DMA_BIDIRECTIONAL;
43 	dir_dst = diff_dst ? DMA_FROM_DEVICE : DMA_BIDIRECTIONAL;
44 
45 	error = qce_dma_terminate_all(&qce->dma);
46 	if (error)
47 		dev_dbg(qce->dev, "skcipher dma termination error (%d)\n",
48 			error);
49 
50 	if (diff_dst)
51 		dma_unmap_sg(qce->dev, rctx->src_sg, rctx->src_nents, dir_src);
52 	dma_unmap_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);
53 
54 	sg_free_table(&rctx->dst_tbl);
55 
56 	error = qce_check_status(qce, &status);
57 	if (error < 0)
58 		dev_dbg(qce->dev, "skcipher operation error (%x)\n", status);
59 
60 	memcpy(rctx->iv, result_buf->encr_cntr_iv, rctx->ivsize);
61 	qce->async_req_done(tmpl->qce, error);
62 }
63 
64 static int
qce_skcipher_async_req_handle(struct crypto_async_request * async_req)65 qce_skcipher_async_req_handle(struct crypto_async_request *async_req)
66 {
67 	struct skcipher_request *req = skcipher_request_cast(async_req);
68 	struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
69 	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
70 	struct qce_alg_template *tmpl = to_cipher_tmpl(crypto_skcipher_reqtfm(req));
71 	struct qce_device *qce = tmpl->qce;
72 	enum dma_data_direction dir_src, dir_dst;
73 	struct scatterlist *sg;
74 	bool diff_dst;
75 	gfp_t gfp;
76 	int dst_nents, src_nents, ret;
77 
78 	rctx->iv = req->iv;
79 	rctx->ivsize = crypto_skcipher_ivsize(skcipher);
80 	rctx->cryptlen = req->cryptlen;
81 
82 	diff_dst = (req->src != req->dst) ? true : false;
83 	dir_src = diff_dst ? DMA_TO_DEVICE : DMA_BIDIRECTIONAL;
84 	dir_dst = diff_dst ? DMA_FROM_DEVICE : DMA_BIDIRECTIONAL;
85 
86 	rctx->src_nents = sg_nents_for_len(req->src, req->cryptlen);
87 	if (diff_dst)
88 		rctx->dst_nents = sg_nents_for_len(req->dst, req->cryptlen);
89 	else
90 		rctx->dst_nents = rctx->src_nents;
91 	if (rctx->src_nents < 0) {
92 		dev_err(qce->dev, "Invalid numbers of src SG.\n");
93 		return rctx->src_nents;
94 	}
95 	if (rctx->dst_nents < 0) {
96 		dev_err(qce->dev, "Invalid numbers of dst SG.\n");
97 		return -rctx->dst_nents;
98 	}
99 
100 	rctx->dst_nents += 1;
101 
102 	gfp = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
103 						GFP_KERNEL : GFP_ATOMIC;
104 
105 	ret = sg_alloc_table(&rctx->dst_tbl, rctx->dst_nents, gfp);
106 	if (ret)
107 		return ret;
108 
109 	sg_init_one(&rctx->result_sg, qce->dma.result_buf, QCE_RESULT_BUF_SZ);
110 
111 	sg = qce_sgtable_add(&rctx->dst_tbl, req->dst, req->cryptlen);
112 	if (IS_ERR(sg)) {
113 		ret = PTR_ERR(sg);
114 		goto error_free;
115 	}
116 
117 	sg = qce_sgtable_add(&rctx->dst_tbl, &rctx->result_sg,
118 			     QCE_RESULT_BUF_SZ);
119 	if (IS_ERR(sg)) {
120 		ret = PTR_ERR(sg);
121 		goto error_free;
122 	}
123 
124 	sg_mark_end(sg);
125 	rctx->dst_sg = rctx->dst_tbl.sgl;
126 
127 	dst_nents = dma_map_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);
128 	if (!dst_nents) {
129 		ret = -EIO;
130 		goto error_free;
131 	}
132 
133 	if (diff_dst) {
134 		src_nents = dma_map_sg(qce->dev, req->src, rctx->src_nents, dir_src);
135 		if (!src_nents) {
136 			ret = -EIO;
137 			goto error_unmap_dst;
138 		}
139 		rctx->src_sg = req->src;
140 	} else {
141 		rctx->src_sg = rctx->dst_sg;
142 		src_nents = dst_nents - 1;
143 	}
144 
145 	ret = qce_dma_prep_sgs(&qce->dma, rctx->src_sg, src_nents,
146 			       rctx->dst_sg, dst_nents,
147 			       qce_skcipher_done, async_req);
148 	if (ret)
149 		goto error_unmap_src;
150 
151 	qce_dma_issue_pending(&qce->dma);
152 
153 	ret = qce_start(async_req, tmpl->crypto_alg_type);
154 	if (ret)
155 		goto error_terminate;
156 
157 	return 0;
158 
159 error_terminate:
160 	qce_dma_terminate_all(&qce->dma);
161 error_unmap_src:
162 	if (diff_dst)
163 		dma_unmap_sg(qce->dev, req->src, rctx->src_nents, dir_src);
164 error_unmap_dst:
165 	dma_unmap_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);
166 error_free:
167 	sg_free_table(&rctx->dst_tbl);
168 	return ret;
169 }
170 
qce_skcipher_setkey(struct crypto_skcipher * ablk,const u8 * key,unsigned int keylen)171 static int qce_skcipher_setkey(struct crypto_skcipher *ablk, const u8 *key,
172 				 unsigned int keylen)
173 {
174 	struct crypto_tfm *tfm = crypto_skcipher_tfm(ablk);
175 	struct qce_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
176 	unsigned long flags = to_cipher_tmpl(ablk)->alg_flags;
177 	unsigned int __keylen;
178 	int ret;
179 
180 	if (!key || !keylen)
181 		return -EINVAL;
182 
183 	/*
184 	 * AES XTS key1 = key2 not supported by crypto engine.
185 	 * Revisit to request a fallback cipher in this case.
186 	 */
187 	if (IS_XTS(flags)) {
188 		__keylen = keylen >> 1;
189 		if (!memcmp(key, key + __keylen, __keylen))
190 			return -ENOKEY;
191 	} else {
192 		__keylen = keylen;
193 	}
194 
195 	switch (__keylen) {
196 	case AES_KEYSIZE_128:
197 	case AES_KEYSIZE_256:
198 		memcpy(ctx->enc_key, key, keylen);
199 		break;
200 	case AES_KEYSIZE_192:
201 		break;
202 	default:
203 		return -EINVAL;
204 	}
205 
206 	ret = crypto_skcipher_setkey(ctx->fallback, key, keylen);
207 	if (!ret)
208 		ctx->enc_keylen = keylen;
209 	return ret;
210 }
211 
qce_des_setkey(struct crypto_skcipher * ablk,const u8 * key,unsigned int keylen)212 static int qce_des_setkey(struct crypto_skcipher *ablk, const u8 *key,
213 			  unsigned int keylen)
214 {
215 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(ablk);
216 	int err;
217 
218 	err = verify_skcipher_des_key(ablk, key);
219 	if (err)
220 		return err;
221 
222 	ctx->enc_keylen = keylen;
223 	memcpy(ctx->enc_key, key, keylen);
224 	return 0;
225 }
226 
qce_des3_setkey(struct crypto_skcipher * ablk,const u8 * key,unsigned int keylen)227 static int qce_des3_setkey(struct crypto_skcipher *ablk, const u8 *key,
228 			   unsigned int keylen)
229 {
230 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(ablk);
231 	u32 _key[6];
232 	int err;
233 
234 	err = verify_skcipher_des3_key(ablk, key);
235 	if (err)
236 		return err;
237 
238 	/*
239 	 * The crypto engine does not support any two keys
240 	 * being the same for triple des algorithms. The
241 	 * verify_skcipher_des3_key does not check for all the
242 	 * below conditions. Return -ENOKEY in case any two keys
243 	 * are the same. Revisit to see if a fallback cipher
244 	 * is needed to handle this condition.
245 	 */
246 	memcpy(_key, key, DES3_EDE_KEY_SIZE);
247 	if (!((_key[0] ^ _key[2]) | (_key[1] ^ _key[3])) ||
248 	    !((_key[2] ^ _key[4]) | (_key[3] ^ _key[5])) ||
249 	    !((_key[0] ^ _key[4]) | (_key[1] ^ _key[5])))
250 		return -ENOKEY;
251 
252 	ctx->enc_keylen = keylen;
253 	memcpy(ctx->enc_key, key, keylen);
254 	return 0;
255 }
256 
qce_skcipher_crypt(struct skcipher_request * req,int encrypt)257 static int qce_skcipher_crypt(struct skcipher_request *req, int encrypt)
258 {
259 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
260 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);
261 	struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
262 	struct qce_alg_template *tmpl = to_cipher_tmpl(tfm);
263 	unsigned int blocksize = crypto_skcipher_blocksize(tfm);
264 	int keylen;
265 	int ret;
266 
267 	rctx->flags = tmpl->alg_flags;
268 	rctx->flags |= encrypt ? QCE_ENCRYPT : QCE_DECRYPT;
269 	keylen = IS_XTS(rctx->flags) ? ctx->enc_keylen >> 1 : ctx->enc_keylen;
270 
271 	/* CE does not handle 0 length messages */
272 	if (!req->cryptlen)
273 		return 0;
274 
275 	/*
276 	 * ECB and CBC algorithms require message lengths to be
277 	 * multiples of block size.
278 	 */
279 	if (IS_ECB(rctx->flags) || IS_CBC(rctx->flags))
280 		if (!IS_ALIGNED(req->cryptlen, blocksize))
281 			return -EINVAL;
282 
283 	/*
284 	 * Conditions for requesting a fallback cipher
285 	 * AES-192 (not supported by crypto engine (CE))
286 	 * AES-XTS request with len <= 512 byte (not recommended to use CE)
287 	 * AES-XTS request with len > QCE_SECTOR_SIZE and
288 	 * is not a multiple of it.(Revisit this condition to check if it is
289 	 * needed in all versions of CE)
290 	 */
291 	if (IS_AES(rctx->flags) &&
292 	    ((keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_256) ||
293 	    (IS_XTS(rctx->flags) && ((req->cryptlen <= aes_sw_max_len) ||
294 	    (req->cryptlen > QCE_SECTOR_SIZE &&
295 	    req->cryptlen % QCE_SECTOR_SIZE))))) {
296 		skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
297 		skcipher_request_set_callback(&rctx->fallback_req,
298 					      req->base.flags,
299 					      req->base.complete,
300 					      req->base.data);
301 		skcipher_request_set_crypt(&rctx->fallback_req, req->src,
302 					   req->dst, req->cryptlen, req->iv);
303 		ret = encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) :
304 				crypto_skcipher_decrypt(&rctx->fallback_req);
305 		return ret;
306 	}
307 
308 	return tmpl->qce->async_req_enqueue(tmpl->qce, &req->base);
309 }
310 
qce_skcipher_encrypt(struct skcipher_request * req)311 static int qce_skcipher_encrypt(struct skcipher_request *req)
312 {
313 	return qce_skcipher_crypt(req, 1);
314 }
315 
qce_skcipher_decrypt(struct skcipher_request * req)316 static int qce_skcipher_decrypt(struct skcipher_request *req)
317 {
318 	return qce_skcipher_crypt(req, 0);
319 }
320 
qce_skcipher_init(struct crypto_skcipher * tfm)321 static int qce_skcipher_init(struct crypto_skcipher *tfm)
322 {
323 	/* take the size without the fallback skcipher_request at the end */
324 	crypto_skcipher_set_reqsize(tfm, offsetof(struct qce_cipher_reqctx,
325 						  fallback_req));
326 	return 0;
327 }
328 
qce_skcipher_init_fallback(struct crypto_skcipher * tfm)329 static int qce_skcipher_init_fallback(struct crypto_skcipher *tfm)
330 {
331 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);
332 
333 	ctx->fallback = crypto_alloc_skcipher(crypto_tfm_alg_name(&tfm->base),
334 					      0, CRYPTO_ALG_NEED_FALLBACK);
335 	if (IS_ERR(ctx->fallback))
336 		return PTR_ERR(ctx->fallback);
337 
338 	crypto_skcipher_set_reqsize(tfm, sizeof(struct qce_cipher_reqctx) +
339 					 crypto_skcipher_reqsize(ctx->fallback));
340 	return 0;
341 }
342 
qce_skcipher_exit(struct crypto_skcipher * tfm)343 static void qce_skcipher_exit(struct crypto_skcipher *tfm)
344 {
345 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);
346 
347 	crypto_free_skcipher(ctx->fallback);
348 }
349 
350 struct qce_skcipher_def {
351 	unsigned long flags;
352 	const char *name;
353 	const char *drv_name;
354 	unsigned int blocksize;
355 	unsigned int chunksize;
356 	unsigned int ivsize;
357 	unsigned int min_keysize;
358 	unsigned int max_keysize;
359 };
360 
361 static const struct qce_skcipher_def skcipher_def[] = {
362 	{
363 		.flags		= QCE_ALG_AES | QCE_MODE_ECB,
364 		.name		= "ecb(aes)",
365 		.drv_name	= "ecb-aes-qce",
366 		.blocksize	= AES_BLOCK_SIZE,
367 		.ivsize		= 0,
368 		.min_keysize	= AES_MIN_KEY_SIZE,
369 		.max_keysize	= AES_MAX_KEY_SIZE,
370 	},
371 	{
372 		.flags		= QCE_ALG_AES | QCE_MODE_CBC,
373 		.name		= "cbc(aes)",
374 		.drv_name	= "cbc-aes-qce",
375 		.blocksize	= AES_BLOCK_SIZE,
376 		.ivsize		= AES_BLOCK_SIZE,
377 		.min_keysize	= AES_MIN_KEY_SIZE,
378 		.max_keysize	= AES_MAX_KEY_SIZE,
379 	},
380 	{
381 		.flags		= QCE_ALG_AES | QCE_MODE_CTR,
382 		.name		= "ctr(aes)",
383 		.drv_name	= "ctr-aes-qce",
384 		.blocksize	= 1,
385 		.chunksize	= AES_BLOCK_SIZE,
386 		.ivsize		= AES_BLOCK_SIZE,
387 		.min_keysize	= AES_MIN_KEY_SIZE,
388 		.max_keysize	= AES_MAX_KEY_SIZE,
389 	},
390 	{
391 		.flags		= QCE_ALG_AES | QCE_MODE_XTS,
392 		.name		= "xts(aes)",
393 		.drv_name	= "xts-aes-qce",
394 		.blocksize	= AES_BLOCK_SIZE,
395 		.ivsize		= AES_BLOCK_SIZE,
396 		.min_keysize	= AES_MIN_KEY_SIZE * 2,
397 		.max_keysize	= AES_MAX_KEY_SIZE * 2,
398 	},
399 	{
400 		.flags		= QCE_ALG_DES | QCE_MODE_ECB,
401 		.name		= "ecb(des)",
402 		.drv_name	= "ecb-des-qce",
403 		.blocksize	= DES_BLOCK_SIZE,
404 		.ivsize		= 0,
405 		.min_keysize	= DES_KEY_SIZE,
406 		.max_keysize	= DES_KEY_SIZE,
407 	},
408 	{
409 		.flags		= QCE_ALG_DES | QCE_MODE_CBC,
410 		.name		= "cbc(des)",
411 		.drv_name	= "cbc-des-qce",
412 		.blocksize	= DES_BLOCK_SIZE,
413 		.ivsize		= DES_BLOCK_SIZE,
414 		.min_keysize	= DES_KEY_SIZE,
415 		.max_keysize	= DES_KEY_SIZE,
416 	},
417 	{
418 		.flags		= QCE_ALG_3DES | QCE_MODE_ECB,
419 		.name		= "ecb(des3_ede)",
420 		.drv_name	= "ecb-3des-qce",
421 		.blocksize	= DES3_EDE_BLOCK_SIZE,
422 		.ivsize		= 0,
423 		.min_keysize	= DES3_EDE_KEY_SIZE,
424 		.max_keysize	= DES3_EDE_KEY_SIZE,
425 	},
426 	{
427 		.flags		= QCE_ALG_3DES | QCE_MODE_CBC,
428 		.name		= "cbc(des3_ede)",
429 		.drv_name	= "cbc-3des-qce",
430 		.blocksize	= DES3_EDE_BLOCK_SIZE,
431 		.ivsize		= DES3_EDE_BLOCK_SIZE,
432 		.min_keysize	= DES3_EDE_KEY_SIZE,
433 		.max_keysize	= DES3_EDE_KEY_SIZE,
434 	},
435 };
436 
qce_skcipher_register_one(const struct qce_skcipher_def * def,struct qce_device * qce)437 static int qce_skcipher_register_one(const struct qce_skcipher_def *def,
438 				       struct qce_device *qce)
439 {
440 	struct qce_alg_template *tmpl;
441 	struct skcipher_alg *alg;
442 	int ret;
443 
444 	tmpl = kzalloc_obj(*tmpl);
445 	if (!tmpl)
446 		return -ENOMEM;
447 
448 	alg = &tmpl->alg.skcipher;
449 
450 	strscpy(alg->base.cra_name, def->name);
451 	strscpy(alg->base.cra_driver_name, def->drv_name);
452 
453 	alg->base.cra_blocksize		= def->blocksize;
454 	alg->chunksize			= def->chunksize;
455 	alg->ivsize			= def->ivsize;
456 	alg->min_keysize		= def->min_keysize;
457 	alg->max_keysize		= def->max_keysize;
458 	alg->setkey			= IS_3DES(def->flags) ? qce_des3_setkey :
459 					  IS_DES(def->flags) ? qce_des_setkey :
460 					  qce_skcipher_setkey;
461 	alg->encrypt			= qce_skcipher_encrypt;
462 	alg->decrypt			= qce_skcipher_decrypt;
463 
464 	alg->base.cra_priority		= 275;
465 	alg->base.cra_flags		= CRYPTO_ALG_ASYNC |
466 					  CRYPTO_ALG_ALLOCATES_MEMORY |
467 					  CRYPTO_ALG_KERN_DRIVER_ONLY;
468 	alg->base.cra_ctxsize		= sizeof(struct qce_cipher_ctx);
469 	alg->base.cra_alignmask		= 0;
470 	alg->base.cra_module		= THIS_MODULE;
471 
472 	if (IS_AES(def->flags)) {
473 		alg->base.cra_flags    |= CRYPTO_ALG_NEED_FALLBACK;
474 		alg->init		= qce_skcipher_init_fallback;
475 		alg->exit		= qce_skcipher_exit;
476 	} else {
477 		alg->init		= qce_skcipher_init;
478 	}
479 
480 	INIT_LIST_HEAD(&tmpl->entry);
481 	tmpl->crypto_alg_type = CRYPTO_ALG_TYPE_SKCIPHER;
482 	tmpl->alg_flags = def->flags;
483 	tmpl->qce = qce;
484 
485 	ret = crypto_register_skcipher(alg);
486 	if (ret) {
487 		dev_err(qce->dev, "%s registration failed\n", alg->base.cra_name);
488 		kfree(tmpl);
489 		return ret;
490 	}
491 
492 	list_add_tail(&tmpl->entry, &skcipher_algs);
493 	dev_dbg(qce->dev, "%s is registered\n", alg->base.cra_name);
494 	return 0;
495 }
496 
qce_skcipher_unregister(struct qce_device * qce)497 static void qce_skcipher_unregister(struct qce_device *qce)
498 {
499 	struct qce_alg_template *tmpl, *n;
500 
501 	list_for_each_entry_safe(tmpl, n, &skcipher_algs, entry) {
502 		crypto_unregister_skcipher(&tmpl->alg.skcipher);
503 		list_del(&tmpl->entry);
504 		kfree(tmpl);
505 	}
506 }
507 
qce_skcipher_register(struct qce_device * qce)508 static int qce_skcipher_register(struct qce_device *qce)
509 {
510 	int ret, i;
511 
512 	for (i = 0; i < ARRAY_SIZE(skcipher_def); i++) {
513 		ret = qce_skcipher_register_one(&skcipher_def[i], qce);
514 		if (ret)
515 			goto err;
516 	}
517 
518 	return 0;
519 err:
520 	qce_skcipher_unregister(qce);
521 	return ret;
522 }
523 
524 const struct qce_algo_ops skcipher_ops = {
525 	.type = CRYPTO_ALG_TYPE_SKCIPHER,
526 	.register_algs = qce_skcipher_register,
527 	.unregister_algs = qce_skcipher_unregister,
528 	.async_req_handle = qce_skcipher_async_req_handle,
529 };
530