xref: /linux/drivers/crypto/ccp/ccp-crypto-aes.c (revision 53597deca0e38c30e6cd4ba2114fa42d2bcd85bb)
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 <crypto/aes.h>
11 #include <crypto/ctr.h>
12 #include <crypto/internal/skcipher.h>
13 #include <linux/err.h>
14 #include <linux/kernel.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/scatterlist.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 
21 #include "ccp-crypto.h"
22 
23 static int ccp_aes_complete(struct crypto_async_request *async_req, int ret)
24 {
25 	struct skcipher_request *req = skcipher_request_cast(async_req);
26 	struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(
27 		crypto_skcipher_reqtfm(req));
28 	struct ccp_aes_req_ctx *rctx = skcipher_request_ctx_dma(req);
29 
30 	if (ret)
31 		return ret;
32 
33 	if (ctx->u.aes.mode != CCP_AES_MODE_ECB) {
34 		size_t ivsize = crypto_skcipher_ivsize(crypto_skcipher_reqtfm(req));
35 
36 		memcpy(req->iv, rctx->iv, ivsize);
37 	}
38 
39 	return 0;
40 }
41 
42 static int ccp_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
43 			  unsigned int key_len)
44 {
45 	struct ccp_crypto_skcipher_alg *alg = ccp_crypto_skcipher_alg(tfm);
46 	struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
47 
48 	switch (key_len) {
49 	case AES_KEYSIZE_128:
50 		ctx->u.aes.type = CCP_AES_TYPE_128;
51 		break;
52 	case AES_KEYSIZE_192:
53 		ctx->u.aes.type = CCP_AES_TYPE_192;
54 		break;
55 	case AES_KEYSIZE_256:
56 		ctx->u.aes.type = CCP_AES_TYPE_256;
57 		break;
58 	default:
59 		return -EINVAL;
60 	}
61 	ctx->u.aes.mode = alg->mode;
62 	ctx->u.aes.key_len = key_len;
63 
64 	memcpy(ctx->u.aes.key, key, key_len);
65 	sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
66 
67 	return 0;
68 }
69 
70 static int ccp_aes_crypt(struct skcipher_request *req, bool encrypt)
71 {
72 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
73 	struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
74 	struct ccp_aes_req_ctx *rctx = skcipher_request_ctx_dma(req);
75 	struct scatterlist *iv_sg = NULL;
76 	unsigned int iv_len = 0;
77 
78 	if (!ctx->u.aes.key_len)
79 		return -EINVAL;
80 
81 	if (((ctx->u.aes.mode == CCP_AES_MODE_ECB) ||
82 	     (ctx->u.aes.mode == CCP_AES_MODE_CBC)) &&
83 	    (req->cryptlen & (AES_BLOCK_SIZE - 1)))
84 		return -EINVAL;
85 
86 	if (ctx->u.aes.mode != CCP_AES_MODE_ECB) {
87 		if (!req->iv)
88 			return -EINVAL;
89 
90 		memcpy(rctx->iv, req->iv, AES_BLOCK_SIZE);
91 		iv_sg = &rctx->iv_sg;
92 		iv_len = AES_BLOCK_SIZE;
93 		sg_init_one(iv_sg, rctx->iv, iv_len);
94 	}
95 
96 	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
97 	INIT_LIST_HEAD(&rctx->cmd.entry);
98 	rctx->cmd.engine = CCP_ENGINE_AES;
99 	rctx->cmd.u.aes.type = ctx->u.aes.type;
100 	rctx->cmd.u.aes.mode = ctx->u.aes.mode;
101 	rctx->cmd.u.aes.action =
102 		(encrypt) ? CCP_AES_ACTION_ENCRYPT : CCP_AES_ACTION_DECRYPT;
103 	rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
104 	rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
105 	rctx->cmd.u.aes.iv = iv_sg;
106 	rctx->cmd.u.aes.iv_len = iv_len;
107 	rctx->cmd.u.aes.src = req->src;
108 	rctx->cmd.u.aes.src_len = req->cryptlen;
109 	rctx->cmd.u.aes.dst = req->dst;
110 
111 	return ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
112 }
113 
114 static int ccp_aes_encrypt(struct skcipher_request *req)
115 {
116 	return ccp_aes_crypt(req, true);
117 }
118 
119 static int ccp_aes_decrypt(struct skcipher_request *req)
120 {
121 	return ccp_aes_crypt(req, false);
122 }
123 
124 static int ccp_aes_init_tfm(struct crypto_skcipher *tfm)
125 {
126 	struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
127 
128 	ctx->complete = ccp_aes_complete;
129 	ctx->u.aes.key_len = 0;
130 
131 	crypto_skcipher_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
132 
133 	return 0;
134 }
135 
136 static int ccp_aes_rfc3686_complete(struct crypto_async_request *async_req,
137 				    int ret)
138 {
139 	struct skcipher_request *req = skcipher_request_cast(async_req);
140 	struct ccp_aes_req_ctx *rctx = skcipher_request_ctx_dma(req);
141 
142 	/* Restore the original pointer */
143 	req->iv = rctx->rfc3686_info;
144 
145 	return ccp_aes_complete(async_req, ret);
146 }
147 
148 static int ccp_aes_rfc3686_setkey(struct crypto_skcipher *tfm, const u8 *key,
149 				  unsigned int key_len)
150 {
151 	struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
152 
153 	if (key_len < CTR_RFC3686_NONCE_SIZE)
154 		return -EINVAL;
155 
156 	key_len -= CTR_RFC3686_NONCE_SIZE;
157 	memcpy(ctx->u.aes.nonce, key + key_len, CTR_RFC3686_NONCE_SIZE);
158 
159 	return ccp_aes_setkey(tfm, key, key_len);
160 }
161 
162 static int ccp_aes_rfc3686_crypt(struct skcipher_request *req, bool encrypt)
163 {
164 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
165 	struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
166 	struct ccp_aes_req_ctx *rctx = skcipher_request_ctx_dma(req);
167 	u8 *iv;
168 
169 	/* Initialize the CTR block */
170 	iv = rctx->rfc3686_iv;
171 	memcpy(iv, ctx->u.aes.nonce, CTR_RFC3686_NONCE_SIZE);
172 
173 	iv += CTR_RFC3686_NONCE_SIZE;
174 	memcpy(iv, req->iv, CTR_RFC3686_IV_SIZE);
175 
176 	iv += CTR_RFC3686_IV_SIZE;
177 	*(__be32 *)iv = cpu_to_be32(1);
178 
179 	/* Point to the new IV */
180 	rctx->rfc3686_info = req->iv;
181 	req->iv = rctx->rfc3686_iv;
182 
183 	return ccp_aes_crypt(req, encrypt);
184 }
185 
186 static int ccp_aes_rfc3686_encrypt(struct skcipher_request *req)
187 {
188 	return ccp_aes_rfc3686_crypt(req, true);
189 }
190 
191 static int ccp_aes_rfc3686_decrypt(struct skcipher_request *req)
192 {
193 	return ccp_aes_rfc3686_crypt(req, false);
194 }
195 
196 static int ccp_aes_rfc3686_init_tfm(struct crypto_skcipher *tfm)
197 {
198 	struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
199 
200 	ctx->complete = ccp_aes_rfc3686_complete;
201 	ctx->u.aes.key_len = 0;
202 
203 	crypto_skcipher_set_reqsize_dma(tfm, sizeof(struct ccp_aes_req_ctx));
204 
205 	return 0;
206 }
207 
208 static const struct skcipher_alg ccp_aes_defaults = {
209 	.setkey			= ccp_aes_setkey,
210 	.encrypt		= ccp_aes_encrypt,
211 	.decrypt		= ccp_aes_decrypt,
212 	.min_keysize		= AES_MIN_KEY_SIZE,
213 	.max_keysize		= AES_MAX_KEY_SIZE,
214 	.init			= ccp_aes_init_tfm,
215 
216 	.base.cra_flags		= CRYPTO_ALG_ASYNC |
217 				  CRYPTO_ALG_ALLOCATES_MEMORY |
218 				  CRYPTO_ALG_KERN_DRIVER_ONLY |
219 				  CRYPTO_ALG_NEED_FALLBACK,
220 	.base.cra_blocksize	= AES_BLOCK_SIZE,
221 	.base.cra_ctxsize	= sizeof(struct ccp_ctx) + CRYPTO_DMA_PADDING,
222 	.base.cra_priority	= CCP_CRA_PRIORITY,
223 	.base.cra_module	= THIS_MODULE,
224 };
225 
226 static const struct skcipher_alg ccp_aes_rfc3686_defaults = {
227 	.setkey			= ccp_aes_rfc3686_setkey,
228 	.encrypt		= ccp_aes_rfc3686_encrypt,
229 	.decrypt		= ccp_aes_rfc3686_decrypt,
230 	.min_keysize		= AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
231 	.max_keysize		= AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
232 	.init			= ccp_aes_rfc3686_init_tfm,
233 
234 	.base.cra_flags		= CRYPTO_ALG_ASYNC |
235 				  CRYPTO_ALG_ALLOCATES_MEMORY |
236 				  CRYPTO_ALG_KERN_DRIVER_ONLY |
237 				  CRYPTO_ALG_NEED_FALLBACK,
238 	.base.cra_blocksize	= CTR_RFC3686_BLOCK_SIZE,
239 	.base.cra_ctxsize	= sizeof(struct ccp_ctx) + CRYPTO_DMA_PADDING,
240 	.base.cra_priority	= CCP_CRA_PRIORITY,
241 	.base.cra_module	= THIS_MODULE,
242 };
243 
244 struct ccp_aes_def {
245 	enum ccp_aes_mode mode;
246 	unsigned int version;
247 	const char *name;
248 	const char *driver_name;
249 	unsigned int blocksize;
250 	unsigned int ivsize;
251 	const struct skcipher_alg *alg_defaults;
252 };
253 
254 static struct ccp_aes_def aes_algs[] = {
255 	{
256 		.mode		= CCP_AES_MODE_ECB,
257 		.version	= CCP_VERSION(3, 0),
258 		.name		= "ecb(aes)",
259 		.driver_name	= "ecb-aes-ccp",
260 		.blocksize	= AES_BLOCK_SIZE,
261 		.ivsize		= 0,
262 		.alg_defaults	= &ccp_aes_defaults,
263 	},
264 	{
265 		.mode		= CCP_AES_MODE_CBC,
266 		.version	= CCP_VERSION(3, 0),
267 		.name		= "cbc(aes)",
268 		.driver_name	= "cbc-aes-ccp",
269 		.blocksize	= AES_BLOCK_SIZE,
270 		.ivsize		= AES_BLOCK_SIZE,
271 		.alg_defaults	= &ccp_aes_defaults,
272 	},
273 	{
274 		.mode		= CCP_AES_MODE_CTR,
275 		.version	= CCP_VERSION(3, 0),
276 		.name		= "ctr(aes)",
277 		.driver_name	= "ctr-aes-ccp",
278 		.blocksize	= 1,
279 		.ivsize		= AES_BLOCK_SIZE,
280 		.alg_defaults	= &ccp_aes_defaults,
281 	},
282 	{
283 		.mode		= CCP_AES_MODE_CTR,
284 		.version	= CCP_VERSION(3, 0),
285 		.name		= "rfc3686(ctr(aes))",
286 		.driver_name	= "rfc3686-ctr-aes-ccp",
287 		.blocksize	= 1,
288 		.ivsize		= CTR_RFC3686_IV_SIZE,
289 		.alg_defaults	= &ccp_aes_rfc3686_defaults,
290 	},
291 };
292 
293 static int ccp_register_aes_alg(struct list_head *head,
294 				const struct ccp_aes_def *def)
295 {
296 	struct ccp_crypto_skcipher_alg *ccp_alg;
297 	struct skcipher_alg *alg;
298 	int ret;
299 
300 	ccp_alg = kzalloc_obj(*ccp_alg);
301 	if (!ccp_alg)
302 		return -ENOMEM;
303 
304 	INIT_LIST_HEAD(&ccp_alg->entry);
305 
306 	ccp_alg->mode = def->mode;
307 
308 	/* Copy the defaults and override as necessary */
309 	alg = &ccp_alg->alg;
310 	*alg = *def->alg_defaults;
311 	strscpy(alg->base.cra_name, def->name);
312 	strscpy(alg->base.cra_driver_name, def->driver_name);
313 	alg->base.cra_blocksize = def->blocksize;
314 	alg->ivsize = def->ivsize;
315 
316 	ret = crypto_register_skcipher(alg);
317 	if (ret) {
318 		pr_err("%s skcipher algorithm registration error (%d)\n",
319 		       alg->base.cra_name, ret);
320 		kfree(ccp_alg);
321 		return ret;
322 	}
323 
324 	list_add(&ccp_alg->entry, head);
325 
326 	return 0;
327 }
328 
329 int ccp_register_aes_algs(struct list_head *head)
330 {
331 	int i, ret;
332 	unsigned int ccpversion = ccp_version();
333 
334 	for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
335 		if (aes_algs[i].version > ccpversion)
336 			continue;
337 		ret = ccp_register_aes_alg(head, &aes_algs[i]);
338 		if (ret)
339 			return ret;
340 	}
341 
342 	return 0;
343 }
344