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