xref: /linux/drivers/crypto/ccp/ccp-crypto-aes.c (revision e9a83bd2322035ed9d7dcf35753d3f984d76c6a5) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AMD Cryptographic Coprocessor (CCP) AES crypto API support
4  *
5  * Copyright (C) 2013-2019 Advanced Micro Devices, Inc.
6  *
7  * Author: Tom Lendacky <thomas.lendacky@amd.com>
8  */
9 
10 #include <linux/module.h>
11 #include <linux/sched.h>
12 #include <linux/delay.h>
13 #include <linux/scatterlist.h>
14 #include <linux/crypto.h>
15 #include <crypto/algapi.h>
16 #include <crypto/aes.h>
17 #include <crypto/ctr.h>
18 #include <crypto/scatterwalk.h>
19 
20 #include "ccp-crypto.h"
21 
22 static int ccp_aes_complete(struct crypto_async_request *async_req, int ret)
23 {
24 	struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
25 	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
26 	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
27 
28 	if (ret)
29 		return ret;
30 
31 	if (ctx->u.aes.mode != CCP_AES_MODE_ECB)
32 		memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
33 
34 	return 0;
35 }
36 
37 static int ccp_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
38 			  unsigned int key_len)
39 {
40 	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
41 	struct ccp_crypto_ablkcipher_alg *alg =
42 		ccp_crypto_ablkcipher_alg(crypto_ablkcipher_tfm(tfm));
43 
44 	switch (key_len) {
45 	case AES_KEYSIZE_128:
46 		ctx->u.aes.type = CCP_AES_TYPE_128;
47 		break;
48 	case AES_KEYSIZE_192:
49 		ctx->u.aes.type = CCP_AES_TYPE_192;
50 		break;
51 	case AES_KEYSIZE_256:
52 		ctx->u.aes.type = CCP_AES_TYPE_256;
53 		break;
54 	default:
55 		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
56 		return -EINVAL;
57 	}
58 	ctx->u.aes.mode = alg->mode;
59 	ctx->u.aes.key_len = key_len;
60 
61 	memcpy(ctx->u.aes.key, key, key_len);
62 	sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
63 
64 	return 0;
65 }
66 
67 static int ccp_aes_crypt(struct ablkcipher_request *req, bool encrypt)
68 {
69 	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
70 	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
71 	struct scatterlist *iv_sg = NULL;
72 	unsigned int iv_len = 0;
73 	int ret;
74 
75 	if (!ctx->u.aes.key_len)
76 		return -EINVAL;
77 
78 	if (((ctx->u.aes.mode == CCP_AES_MODE_ECB) ||
79 	     (ctx->u.aes.mode == CCP_AES_MODE_CBC)) &&
80 	    (req->nbytes & (AES_BLOCK_SIZE - 1)))
81 		return -EINVAL;
82 
83 	if (ctx->u.aes.mode != CCP_AES_MODE_ECB) {
84 		if (!req->info)
85 			return -EINVAL;
86 
87 		memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
88 		iv_sg = &rctx->iv_sg;
89 		iv_len = AES_BLOCK_SIZE;
90 		sg_init_one(iv_sg, rctx->iv, iv_len);
91 	}
92 
93 	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
94 	INIT_LIST_HEAD(&rctx->cmd.entry);
95 	rctx->cmd.engine = CCP_ENGINE_AES;
96 	rctx->cmd.u.aes.type = ctx->u.aes.type;
97 	rctx->cmd.u.aes.mode = ctx->u.aes.mode;
98 	rctx->cmd.u.aes.action =
99 		(encrypt) ? CCP_AES_ACTION_ENCRYPT : CCP_AES_ACTION_DECRYPT;
100 	rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
101 	rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
102 	rctx->cmd.u.aes.iv = iv_sg;
103 	rctx->cmd.u.aes.iv_len = iv_len;
104 	rctx->cmd.u.aes.src = req->src;
105 	rctx->cmd.u.aes.src_len = req->nbytes;
106 	rctx->cmd.u.aes.dst = req->dst;
107 
108 	ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
109 
110 	return ret;
111 }
112 
113 static int ccp_aes_encrypt(struct ablkcipher_request *req)
114 {
115 	return ccp_aes_crypt(req, true);
116 }
117 
118 static int ccp_aes_decrypt(struct ablkcipher_request *req)
119 {
120 	return ccp_aes_crypt(req, false);
121 }
122 
123 static int ccp_aes_cra_init(struct crypto_tfm *tfm)
124 {
125 	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
126 
127 	ctx->complete = ccp_aes_complete;
128 	ctx->u.aes.key_len = 0;
129 
130 	tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx);
131 
132 	return 0;
133 }
134 
135 static void ccp_aes_cra_exit(struct crypto_tfm *tfm)
136 {
137 }
138 
139 static int ccp_aes_rfc3686_complete(struct crypto_async_request *async_req,
140 				    int ret)
141 {
142 	struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
143 	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
144 
145 	/* Restore the original pointer */
146 	req->info = rctx->rfc3686_info;
147 
148 	return ccp_aes_complete(async_req, ret);
149 }
150 
151 static int ccp_aes_rfc3686_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
152 				  unsigned int key_len)
153 {
154 	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
155 
156 	if (key_len < CTR_RFC3686_NONCE_SIZE)
157 		return -EINVAL;
158 
159 	key_len -= CTR_RFC3686_NONCE_SIZE;
160 	memcpy(ctx->u.aes.nonce, key + key_len, CTR_RFC3686_NONCE_SIZE);
161 
162 	return ccp_aes_setkey(tfm, key, key_len);
163 }
164 
165 static int ccp_aes_rfc3686_crypt(struct ablkcipher_request *req, bool encrypt)
166 {
167 	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
168 	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
169 	u8 *iv;
170 
171 	/* Initialize the CTR block */
172 	iv = rctx->rfc3686_iv;
173 	memcpy(iv, ctx->u.aes.nonce, CTR_RFC3686_NONCE_SIZE);
174 
175 	iv += CTR_RFC3686_NONCE_SIZE;
176 	memcpy(iv, req->info, CTR_RFC3686_IV_SIZE);
177 
178 	iv += CTR_RFC3686_IV_SIZE;
179 	*(__be32 *)iv = cpu_to_be32(1);
180 
181 	/* Point to the new IV */
182 	rctx->rfc3686_info = req->info;
183 	req->info = rctx->rfc3686_iv;
184 
185 	return ccp_aes_crypt(req, encrypt);
186 }
187 
188 static int ccp_aes_rfc3686_encrypt(struct ablkcipher_request *req)
189 {
190 	return ccp_aes_rfc3686_crypt(req, true);
191 }
192 
193 static int ccp_aes_rfc3686_decrypt(struct ablkcipher_request *req)
194 {
195 	return ccp_aes_rfc3686_crypt(req, false);
196 }
197 
198 static int ccp_aes_rfc3686_cra_init(struct crypto_tfm *tfm)
199 {
200 	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
201 
202 	ctx->complete = ccp_aes_rfc3686_complete;
203 	ctx->u.aes.key_len = 0;
204 
205 	tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx);
206 
207 	return 0;
208 }
209 
210 static void ccp_aes_rfc3686_cra_exit(struct crypto_tfm *tfm)
211 {
212 }
213 
214 static struct crypto_alg ccp_aes_defaults = {
215 	.cra_flags	= CRYPTO_ALG_TYPE_ABLKCIPHER |
216 			  CRYPTO_ALG_ASYNC |
217 			  CRYPTO_ALG_KERN_DRIVER_ONLY |
218 			  CRYPTO_ALG_NEED_FALLBACK,
219 	.cra_blocksize	= AES_BLOCK_SIZE,
220 	.cra_ctxsize	= sizeof(struct ccp_ctx),
221 	.cra_priority	= CCP_CRA_PRIORITY,
222 	.cra_type	= &crypto_ablkcipher_type,
223 	.cra_init	= ccp_aes_cra_init,
224 	.cra_exit	= ccp_aes_cra_exit,
225 	.cra_module	= THIS_MODULE,
226 	.cra_ablkcipher	= {
227 		.setkey		= ccp_aes_setkey,
228 		.encrypt	= ccp_aes_encrypt,
229 		.decrypt	= ccp_aes_decrypt,
230 		.min_keysize	= AES_MIN_KEY_SIZE,
231 		.max_keysize	= AES_MAX_KEY_SIZE,
232 	},
233 };
234 
235 static struct crypto_alg ccp_aes_rfc3686_defaults = {
236 	.cra_flags	= CRYPTO_ALG_TYPE_ABLKCIPHER |
237 			   CRYPTO_ALG_ASYNC |
238 			   CRYPTO_ALG_KERN_DRIVER_ONLY |
239 			   CRYPTO_ALG_NEED_FALLBACK,
240 	.cra_blocksize	= CTR_RFC3686_BLOCK_SIZE,
241 	.cra_ctxsize	= sizeof(struct ccp_ctx),
242 	.cra_priority	= CCP_CRA_PRIORITY,
243 	.cra_type	= &crypto_ablkcipher_type,
244 	.cra_init	= ccp_aes_rfc3686_cra_init,
245 	.cra_exit	= ccp_aes_rfc3686_cra_exit,
246 	.cra_module	= THIS_MODULE,
247 	.cra_ablkcipher	= {
248 		.setkey		= ccp_aes_rfc3686_setkey,
249 		.encrypt	= ccp_aes_rfc3686_encrypt,
250 		.decrypt	= ccp_aes_rfc3686_decrypt,
251 		.min_keysize	= AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
252 		.max_keysize	= AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
253 	},
254 };
255 
256 struct ccp_aes_def {
257 	enum ccp_aes_mode mode;
258 	unsigned int version;
259 	const char *name;
260 	const char *driver_name;
261 	unsigned int blocksize;
262 	unsigned int ivsize;
263 	struct crypto_alg *alg_defaults;
264 };
265 
266 static struct ccp_aes_def aes_algs[] = {
267 	{
268 		.mode		= CCP_AES_MODE_ECB,
269 		.version	= CCP_VERSION(3, 0),
270 		.name		= "ecb(aes)",
271 		.driver_name	= "ecb-aes-ccp",
272 		.blocksize	= AES_BLOCK_SIZE,
273 		.ivsize		= 0,
274 		.alg_defaults	= &ccp_aes_defaults,
275 	},
276 	{
277 		.mode		= CCP_AES_MODE_CBC,
278 		.version	= CCP_VERSION(3, 0),
279 		.name		= "cbc(aes)",
280 		.driver_name	= "cbc-aes-ccp",
281 		.blocksize	= AES_BLOCK_SIZE,
282 		.ivsize		= AES_BLOCK_SIZE,
283 		.alg_defaults	= &ccp_aes_defaults,
284 	},
285 	{
286 		.mode		= CCP_AES_MODE_CFB,
287 		.version	= CCP_VERSION(3, 0),
288 		.name		= "cfb(aes)",
289 		.driver_name	= "cfb-aes-ccp",
290 		.blocksize	= 1,
291 		.ivsize		= AES_BLOCK_SIZE,
292 		.alg_defaults	= &ccp_aes_defaults,
293 	},
294 	{
295 		.mode		= CCP_AES_MODE_OFB,
296 		.version	= CCP_VERSION(3, 0),
297 		.name		= "ofb(aes)",
298 		.driver_name	= "ofb-aes-ccp",
299 		.blocksize	= 1,
300 		.ivsize		= AES_BLOCK_SIZE,
301 		.alg_defaults	= &ccp_aes_defaults,
302 	},
303 	{
304 		.mode		= CCP_AES_MODE_CTR,
305 		.version	= CCP_VERSION(3, 0),
306 		.name		= "ctr(aes)",
307 		.driver_name	= "ctr-aes-ccp",
308 		.blocksize	= 1,
309 		.ivsize		= AES_BLOCK_SIZE,
310 		.alg_defaults	= &ccp_aes_defaults,
311 	},
312 	{
313 		.mode		= CCP_AES_MODE_CTR,
314 		.version	= CCP_VERSION(3, 0),
315 		.name		= "rfc3686(ctr(aes))",
316 		.driver_name	= "rfc3686-ctr-aes-ccp",
317 		.blocksize	= 1,
318 		.ivsize		= CTR_RFC3686_IV_SIZE,
319 		.alg_defaults	= &ccp_aes_rfc3686_defaults,
320 	},
321 };
322 
323 static int ccp_register_aes_alg(struct list_head *head,
324 				const struct ccp_aes_def *def)
325 {
326 	struct ccp_crypto_ablkcipher_alg *ccp_alg;
327 	struct crypto_alg *alg;
328 	int ret;
329 
330 	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
331 	if (!ccp_alg)
332 		return -ENOMEM;
333 
334 	INIT_LIST_HEAD(&ccp_alg->entry);
335 
336 	ccp_alg->mode = def->mode;
337 
338 	/* Copy the defaults and override as necessary */
339 	alg = &ccp_alg->alg;
340 	*alg = *def->alg_defaults;
341 	snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
342 	snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
343 		 def->driver_name);
344 	alg->cra_blocksize = def->blocksize;
345 	alg->cra_ablkcipher.ivsize = def->ivsize;
346 
347 	ret = crypto_register_alg(alg);
348 	if (ret) {
349 		pr_err("%s ablkcipher algorithm registration error (%d)\n",
350 		       alg->cra_name, ret);
351 		kfree(ccp_alg);
352 		return ret;
353 	}
354 
355 	list_add(&ccp_alg->entry, head);
356 
357 	return 0;
358 }
359 
360 int ccp_register_aes_algs(struct list_head *head)
361 {
362 	int i, ret;
363 	unsigned int ccpversion = ccp_version();
364 
365 	for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
366 		if (aes_algs[i].version > ccpversion)
367 			continue;
368 		ret = ccp_register_aes_alg(head, &aes_algs[i]);
369 		if (ret)
370 			return ret;
371 	}
372 
373 	return 0;
374 }
375