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