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