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
22static int ccp_aes_complete(struct crypto_async_request *async_req, int ret)
23{
24	struct skcipher_request *req = skcipher_request_cast(async_req);
25	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
26	struct ccp_aes_req_ctx *rctx = skcipher_request_ctx(req);
27
28	if (ret)
29		return ret;
30
31	if (ctx->u.aes.mode != CCP_AES_MODE_ECB)
32		memcpy(req->iv, rctx->iv, AES_BLOCK_SIZE);
33
34	return 0;
35}
36
37static int ccp_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
38			  unsigned int key_len)
39{
40	struct ccp_crypto_skcipher_alg *alg = ccp_crypto_skcipher_alg(tfm);
41	struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
42
43	switch (key_len) {
44	case AES_KEYSIZE_128:
45		ctx->u.aes.type = CCP_AES_TYPE_128;
46		break;
47	case AES_KEYSIZE_192:
48		ctx->u.aes.type = CCP_AES_TYPE_192;
49		break;
50	case AES_KEYSIZE_256:
51		ctx->u.aes.type = CCP_AES_TYPE_256;
52		break;
53	default:
54		return -EINVAL;
55	}
56	ctx->u.aes.mode = alg->mode;
57	ctx->u.aes.key_len = key_len;
58
59	memcpy(ctx->u.aes.key, key, key_len);
60	sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
61
62	return 0;
63}
64
65static int ccp_aes_crypt(struct skcipher_request *req, bool encrypt)
66{
67	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
68	struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
69	struct ccp_aes_req_ctx *rctx = skcipher_request_ctx(req);
70	struct scatterlist *iv_sg = NULL;
71	unsigned int iv_len = 0;
72	int ret;
73
74	if (!ctx->u.aes.key_len)
75		return -EINVAL;
76
77	if (((ctx->u.aes.mode == CCP_AES_MODE_ECB) ||
78	     (ctx->u.aes.mode == CCP_AES_MODE_CBC)) &&
79	    (req->cryptlen & (AES_BLOCK_SIZE - 1)))
80		return -EINVAL;
81
82	if (ctx->u.aes.mode != CCP_AES_MODE_ECB) {
83		if (!req->iv)
84			return -EINVAL;
85
86		memcpy(rctx->iv, req->iv, AES_BLOCK_SIZE);
87		iv_sg = &rctx->iv_sg;
88		iv_len = AES_BLOCK_SIZE;
89		sg_init_one(iv_sg, rctx->iv, iv_len);
90	}
91
92	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
93	INIT_LIST_HEAD(&rctx->cmd.entry);
94	rctx->cmd.engine = CCP_ENGINE_AES;
95	rctx->cmd.u.aes.type = ctx->u.aes.type;
96	rctx->cmd.u.aes.mode = ctx->u.aes.mode;
97	rctx->cmd.u.aes.action =
98		(encrypt) ? CCP_AES_ACTION_ENCRYPT : CCP_AES_ACTION_DECRYPT;
99	rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
100	rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
101	rctx->cmd.u.aes.iv = iv_sg;
102	rctx->cmd.u.aes.iv_len = iv_len;
103	rctx->cmd.u.aes.src = req->src;
104	rctx->cmd.u.aes.src_len = req->cryptlen;
105	rctx->cmd.u.aes.dst = req->dst;
106
107	ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
108
109	return ret;
110}
111
112static int ccp_aes_encrypt(struct skcipher_request *req)
113{
114	return ccp_aes_crypt(req, true);
115}
116
117static int ccp_aes_decrypt(struct skcipher_request *req)
118{
119	return ccp_aes_crypt(req, false);
120}
121
122static int ccp_aes_init_tfm(struct crypto_skcipher *tfm)
123{
124	struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
125
126	ctx->complete = ccp_aes_complete;
127	ctx->u.aes.key_len = 0;
128
129	crypto_skcipher_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
130
131	return 0;
132}
133
134static int ccp_aes_rfc3686_complete(struct crypto_async_request *async_req,
135				    int ret)
136{
137	struct skcipher_request *req = skcipher_request_cast(async_req);
138	struct ccp_aes_req_ctx *rctx = skcipher_request_ctx(req);
139
140	/* Restore the original pointer */
141	req->iv = rctx->rfc3686_info;
142
143	return ccp_aes_complete(async_req, ret);
144}
145
146static int ccp_aes_rfc3686_setkey(struct crypto_skcipher *tfm, const u8 *key,
147				  unsigned int key_len)
148{
149	struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
150
151	if (key_len < CTR_RFC3686_NONCE_SIZE)
152		return -EINVAL;
153
154	key_len -= CTR_RFC3686_NONCE_SIZE;
155	memcpy(ctx->u.aes.nonce, key + key_len, CTR_RFC3686_NONCE_SIZE);
156
157	return ccp_aes_setkey(tfm, key, key_len);
158}
159
160static int ccp_aes_rfc3686_crypt(struct skcipher_request *req, bool encrypt)
161{
162	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
163	struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
164	struct ccp_aes_req_ctx *rctx = skcipher_request_ctx(req);
165	u8 *iv;
166
167	/* Initialize the CTR block */
168	iv = rctx->rfc3686_iv;
169	memcpy(iv, ctx->u.aes.nonce, CTR_RFC3686_NONCE_SIZE);
170
171	iv += CTR_RFC3686_NONCE_SIZE;
172	memcpy(iv, req->iv, CTR_RFC3686_IV_SIZE);
173
174	iv += CTR_RFC3686_IV_SIZE;
175	*(__be32 *)iv = cpu_to_be32(1);
176
177	/* Point to the new IV */
178	rctx->rfc3686_info = req->iv;
179	req->iv = rctx->rfc3686_iv;
180
181	return ccp_aes_crypt(req, encrypt);
182}
183
184static int ccp_aes_rfc3686_encrypt(struct skcipher_request *req)
185{
186	return ccp_aes_rfc3686_crypt(req, true);
187}
188
189static int ccp_aes_rfc3686_decrypt(struct skcipher_request *req)
190{
191	return ccp_aes_rfc3686_crypt(req, false);
192}
193
194static int ccp_aes_rfc3686_init_tfm(struct crypto_skcipher *tfm)
195{
196	struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
197
198	ctx->complete = ccp_aes_rfc3686_complete;
199	ctx->u.aes.key_len = 0;
200
201	crypto_skcipher_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
202
203	return 0;
204}
205
206static const struct skcipher_alg ccp_aes_defaults = {
207	.setkey			= ccp_aes_setkey,
208	.encrypt		= ccp_aes_encrypt,
209	.decrypt		= ccp_aes_decrypt,
210	.min_keysize		= AES_MIN_KEY_SIZE,
211	.max_keysize		= AES_MAX_KEY_SIZE,
212	.init			= ccp_aes_init_tfm,
213
214	.base.cra_flags		= CRYPTO_ALG_ASYNC |
215				  CRYPTO_ALG_ALLOCATES_MEMORY |
216				  CRYPTO_ALG_KERN_DRIVER_ONLY |
217				  CRYPTO_ALG_NEED_FALLBACK,
218	.base.cra_blocksize	= AES_BLOCK_SIZE,
219	.base.cra_ctxsize	= sizeof(struct ccp_ctx),
220	.base.cra_priority	= CCP_CRA_PRIORITY,
221	.base.cra_module	= THIS_MODULE,
222};
223
224static const struct skcipher_alg ccp_aes_rfc3686_defaults = {
225	.setkey			= ccp_aes_rfc3686_setkey,
226	.encrypt		= ccp_aes_rfc3686_encrypt,
227	.decrypt		= ccp_aes_rfc3686_decrypt,
228	.min_keysize		= AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
229	.max_keysize		= AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
230	.init			= ccp_aes_rfc3686_init_tfm,
231
232	.base.cra_flags		= CRYPTO_ALG_ASYNC |
233				  CRYPTO_ALG_ALLOCATES_MEMORY |
234				  CRYPTO_ALG_KERN_DRIVER_ONLY |
235				  CRYPTO_ALG_NEED_FALLBACK,
236	.base.cra_blocksize	= CTR_RFC3686_BLOCK_SIZE,
237	.base.cra_ctxsize	= sizeof(struct ccp_ctx),
238	.base.cra_priority	= CCP_CRA_PRIORITY,
239	.base.cra_module	= THIS_MODULE,
240};
241
242struct ccp_aes_def {
243	enum ccp_aes_mode mode;
244	unsigned int version;
245	const char *name;
246	const char *driver_name;
247	unsigned int blocksize;
248	unsigned int ivsize;
249	const struct skcipher_alg *alg_defaults;
250};
251
252static struct ccp_aes_def aes_algs[] = {
253	{
254		.mode		= CCP_AES_MODE_ECB,
255		.version	= CCP_VERSION(3, 0),
256		.name		= "ecb(aes)",
257		.driver_name	= "ecb-aes-ccp",
258		.blocksize	= AES_BLOCK_SIZE,
259		.ivsize		= 0,
260		.alg_defaults	= &ccp_aes_defaults,
261	},
262	{
263		.mode		= CCP_AES_MODE_CBC,
264		.version	= CCP_VERSION(3, 0),
265		.name		= "cbc(aes)",
266		.driver_name	= "cbc-aes-ccp",
267		.blocksize	= AES_BLOCK_SIZE,
268		.ivsize		= AES_BLOCK_SIZE,
269		.alg_defaults	= &ccp_aes_defaults,
270	},
271	{
272		.mode		= CCP_AES_MODE_CFB,
273		.version	= CCP_VERSION(3, 0),
274		.name		= "cfb(aes)",
275		.driver_name	= "cfb-aes-ccp",
276		.blocksize	= 1,
277		.ivsize		= AES_BLOCK_SIZE,
278		.alg_defaults	= &ccp_aes_defaults,
279	},
280	{
281		.mode		= CCP_AES_MODE_OFB,
282		.version	= CCP_VERSION(3, 0),
283		.name		= "ofb(aes)",
284		.driver_name	= "ofb-aes-ccp",
285		.blocksize	= 1,
286		.ivsize		= AES_BLOCK_SIZE,
287		.alg_defaults	= &ccp_aes_defaults,
288	},
289	{
290		.mode		= CCP_AES_MODE_CTR,
291		.version	= CCP_VERSION(3, 0),
292		.name		= "ctr(aes)",
293		.driver_name	= "ctr-aes-ccp",
294		.blocksize	= 1,
295		.ivsize		= AES_BLOCK_SIZE,
296		.alg_defaults	= &ccp_aes_defaults,
297	},
298	{
299		.mode		= CCP_AES_MODE_CTR,
300		.version	= CCP_VERSION(3, 0),
301		.name		= "rfc3686(ctr(aes))",
302		.driver_name	= "rfc3686-ctr-aes-ccp",
303		.blocksize	= 1,
304		.ivsize		= CTR_RFC3686_IV_SIZE,
305		.alg_defaults	= &ccp_aes_rfc3686_defaults,
306	},
307};
308
309static int ccp_register_aes_alg(struct list_head *head,
310				const struct ccp_aes_def *def)
311{
312	struct ccp_crypto_skcipher_alg *ccp_alg;
313	struct skcipher_alg *alg;
314	int ret;
315
316	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
317	if (!ccp_alg)
318		return -ENOMEM;
319
320	INIT_LIST_HEAD(&ccp_alg->entry);
321
322	ccp_alg->mode = def->mode;
323
324	/* Copy the defaults and override as necessary */
325	alg = &ccp_alg->alg;
326	*alg = *def->alg_defaults;
327	snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
328	snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
329		 def->driver_name);
330	alg->base.cra_blocksize = def->blocksize;
331	alg->ivsize = def->ivsize;
332
333	ret = crypto_register_skcipher(alg);
334	if (ret) {
335		pr_err("%s skcipher algorithm registration error (%d)\n",
336		       alg->base.cra_name, ret);
337		kfree(ccp_alg);
338		return ret;
339	}
340
341	list_add(&ccp_alg->entry, head);
342
343	return 0;
344}
345
346int ccp_register_aes_algs(struct list_head *head)
347{
348	int i, ret;
349	unsigned int ccpversion = ccp_version();
350
351	for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
352		if (aes_algs[i].version > ccpversion)
353			continue;
354		ret = ccp_register_aes_alg(head, &aes_algs[i]);
355		if (ret)
356			return ret;
357	}
358
359	return 0;
360}
361