ccp-crypto-aes.c revision 2b789435d7f36ed918d92db647f3a2f3fec9bb1f 
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
25
26static int ccp_aes_complete(struct crypto_async_request *async_req, int ret)
27{
28	struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
29	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
30	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
31
32	if (ret)
33		return ret;
34
35	if (ctx->u.aes.mode != CCP_AES_MODE_ECB)
36		memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
37
38	return 0;
39}
40
41static int ccp_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
42			  unsigned int key_len)
43{
44	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
45	struct ccp_crypto_ablkcipher_alg *alg =
46		ccp_crypto_ablkcipher_alg(crypto_ablkcipher_tfm(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		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
60		return -EINVAL;
61	}
62	ctx->u.aes.mode = alg->mode;
63	ctx->u.aes.key_len = key_len;
64
65	memcpy(ctx->u.aes.key, key, key_len);
66	sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
67
68	return 0;
69}
70
71static int ccp_aes_crypt(struct ablkcipher_request *req, bool encrypt)
72{
73	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
74	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
75	struct scatterlist *iv_sg = NULL;
76	unsigned int iv_len = 0;
77	int ret;
78
79	if (!ctx->u.aes.key_len) {
80		pr_err("AES key not set\n");
81		return -EINVAL;
82	}
83
84	if (((ctx->u.aes.mode == CCP_AES_MODE_ECB) ||
85	     (ctx->u.aes.mode == CCP_AES_MODE_CBC) ||
86	     (ctx->u.aes.mode == CCP_AES_MODE_CFB)) &&
87	    (req->nbytes & (AES_BLOCK_SIZE - 1))) {
88		pr_err("AES request size is not a multiple of the block size\n");
89		return -EINVAL;
90	}
91
92	if (ctx->u.aes.mode != CCP_AES_MODE_ECB) {
93		if (!req->info) {
94			pr_err("AES IV not supplied");
95			return -EINVAL;
96		}
97
98		memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
99		iv_sg = &rctx->iv_sg;
100		iv_len = AES_BLOCK_SIZE;
101		sg_init_one(iv_sg, rctx->iv, iv_len);
102	}
103
104	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
105	INIT_LIST_HEAD(&rctx->cmd.entry);
106	rctx->cmd.engine = CCP_ENGINE_AES;
107	rctx->cmd.u.aes.type = ctx->u.aes.type;
108	rctx->cmd.u.aes.mode = ctx->u.aes.mode;
109	rctx->cmd.u.aes.action =
110		(encrypt) ? CCP_AES_ACTION_ENCRYPT : CCP_AES_ACTION_DECRYPT;
111	rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
112	rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
113	rctx->cmd.u.aes.iv = iv_sg;
114	rctx->cmd.u.aes.iv_len = iv_len;
115	rctx->cmd.u.aes.src = req->src;
116	rctx->cmd.u.aes.src_len = req->nbytes;
117	rctx->cmd.u.aes.dst = req->dst;
118
119	ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
120
121	return ret;
122}
123
124static int ccp_aes_encrypt(struct ablkcipher_request *req)
125{
126	return ccp_aes_crypt(req, true);
127}
128
129static int ccp_aes_decrypt(struct ablkcipher_request *req)
130{
131	return ccp_aes_crypt(req, false);
132}
133
134static int ccp_aes_cra_init(struct crypto_tfm *tfm)
135{
136	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
137
138	ctx->complete = ccp_aes_complete;
139	ctx->u.aes.key_len = 0;
140
141	tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx);
142
143	return 0;
144}
145
146static void ccp_aes_cra_exit(struct crypto_tfm *tfm)
147{
148}
149
150static int ccp_aes_rfc3686_complete(struct crypto_async_request *async_req,
151				    int ret)
152{
153	struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
154	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
155
156	/* Restore the original pointer */
157	req->info = rctx->rfc3686_info;
158
159	return ccp_aes_complete(async_req, ret);
160}
161
162static int ccp_aes_rfc3686_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
163				  unsigned int key_len)
164{
165	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
166
167	if (key_len < CTR_RFC3686_NONCE_SIZE)
168		return -EINVAL;
169
170	key_len -= CTR_RFC3686_NONCE_SIZE;
171	memcpy(ctx->u.aes.nonce, key + key_len, CTR_RFC3686_NONCE_SIZE);
172
173	return ccp_aes_setkey(tfm, key, key_len);
174}
175
176static int ccp_aes_rfc3686_crypt(struct ablkcipher_request *req, bool encrypt)
177{
178	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
179	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
180	u8 *iv;
181
182	/* Initialize the CTR block */
183	iv = rctx->rfc3686_iv;
184	memcpy(iv, ctx->u.aes.nonce, CTR_RFC3686_NONCE_SIZE);
185
186	iv += CTR_RFC3686_NONCE_SIZE;
187	memcpy(iv, req->info, CTR_RFC3686_IV_SIZE);
188
189	iv += CTR_RFC3686_IV_SIZE;
190	*(__be32 *)iv = cpu_to_be32(1);
191
192	/* Point to the new IV */
193	rctx->rfc3686_info = req->info;
194	req->info = rctx->rfc3686_iv;
195
196	return ccp_aes_crypt(req, encrypt);
197}
198
199static int ccp_aes_rfc3686_encrypt(struct ablkcipher_request *req)
200{
201	return ccp_aes_rfc3686_crypt(req, true);
202}
203
204static int ccp_aes_rfc3686_decrypt(struct ablkcipher_request *req)
205{
206	return ccp_aes_rfc3686_crypt(req, false);
207}
208
209static int ccp_aes_rfc3686_cra_init(struct crypto_tfm *tfm)
210{
211	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
212
213	ctx->complete = ccp_aes_rfc3686_complete;
214	ctx->u.aes.key_len = 0;
215
216	tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx);
217
218	return 0;
219}
220
221static void ccp_aes_rfc3686_cra_exit(struct crypto_tfm *tfm)
222{
223}
224
225static struct crypto_alg ccp_aes_defaults = {
226	.cra_flags	= CRYPTO_ALG_TYPE_ABLKCIPHER |
227			  CRYPTO_ALG_ASYNC |
228			  CRYPTO_ALG_KERN_DRIVER_ONLY |
229			  CRYPTO_ALG_NEED_FALLBACK,
230	.cra_blocksize	= AES_BLOCK_SIZE,
231	.cra_ctxsize	= sizeof(struct ccp_ctx),
232	.cra_priority	= CCP_CRA_PRIORITY,
233	.cra_type	= &crypto_ablkcipher_type,
234	.cra_init	= ccp_aes_cra_init,
235	.cra_exit	= ccp_aes_cra_exit,
236	.cra_module	= THIS_MODULE,
237	.cra_ablkcipher	= {
238		.setkey		= ccp_aes_setkey,
239		.encrypt	= ccp_aes_encrypt,
240		.decrypt	= ccp_aes_decrypt,
241		.min_keysize	= AES_MIN_KEY_SIZE,
242		.max_keysize	= AES_MAX_KEY_SIZE,
243	},
244};
245
246static struct crypto_alg ccp_aes_rfc3686_defaults = {
247	.cra_flags	= CRYPTO_ALG_TYPE_ABLKCIPHER |
248			   CRYPTO_ALG_ASYNC |
249			   CRYPTO_ALG_KERN_DRIVER_ONLY |
250			   CRYPTO_ALG_NEED_FALLBACK,
251	.cra_blocksize	= CTR_RFC3686_BLOCK_SIZE,
252	.cra_ctxsize	= sizeof(struct ccp_ctx),
253	.cra_priority	= CCP_CRA_PRIORITY,
254	.cra_type	= &crypto_ablkcipher_type,
255	.cra_init	= ccp_aes_rfc3686_cra_init,
256	.cra_exit	= ccp_aes_rfc3686_cra_exit,
257	.cra_module	= THIS_MODULE,
258	.cra_ablkcipher	= {
259		.setkey		= ccp_aes_rfc3686_setkey,
260		.encrypt	= ccp_aes_rfc3686_encrypt,
261		.decrypt	= ccp_aes_rfc3686_decrypt,
262		.min_keysize	= AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
263		.max_keysize	= AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
264	},
265};
266
267struct ccp_aes_def {
268	enum ccp_aes_mode mode;
269	const char *name;
270	const char *driver_name;
271	unsigned int blocksize;
272	unsigned int ivsize;
273	struct crypto_alg *alg_defaults;
274};
275
276static struct ccp_aes_def aes_algs[] = {
277	{
278		.mode		= CCP_AES_MODE_ECB,
279		.name		= "ecb(aes)",
280		.driver_name	= "ecb-aes-ccp",
281		.blocksize	= AES_BLOCK_SIZE,
282		.ivsize		= 0,
283		.alg_defaults	= &ccp_aes_defaults,
284	},
285	{
286		.mode		= CCP_AES_MODE_CBC,
287		.name		= "cbc(aes)",
288		.driver_name	= "cbc-aes-ccp",
289		.blocksize	= AES_BLOCK_SIZE,
290		.ivsize		= AES_BLOCK_SIZE,
291		.alg_defaults	= &ccp_aes_defaults,
292	},
293	{
294		.mode		= CCP_AES_MODE_CFB,
295		.name		= "cfb(aes)",
296		.driver_name	= "cfb-aes-ccp",
297		.blocksize	= AES_BLOCK_SIZE,
298		.ivsize		= AES_BLOCK_SIZE,
299		.alg_defaults	= &ccp_aes_defaults,
300	},
301	{
302		.mode		= CCP_AES_MODE_OFB,
303		.name		= "ofb(aes)",
304		.driver_name	= "ofb-aes-ccp",
305		.blocksize	= 1,
306		.ivsize		= AES_BLOCK_SIZE,
307		.alg_defaults	= &ccp_aes_defaults,
308	},
309	{
310		.mode		= CCP_AES_MODE_CTR,
311		.name		= "ctr(aes)",
312		.driver_name	= "ctr-aes-ccp",
313		.blocksize	= 1,
314		.ivsize		= AES_BLOCK_SIZE,
315		.alg_defaults	= &ccp_aes_defaults,
316	},
317	{
318		.mode		= CCP_AES_MODE_CTR,
319		.name		= "rfc3686(ctr(aes))",
320		.driver_name	= "rfc3686-ctr-aes-ccp",
321		.blocksize	= 1,
322		.ivsize		= CTR_RFC3686_IV_SIZE,
323		.alg_defaults	= &ccp_aes_rfc3686_defaults,
324	},
325};
326
327static int ccp_register_aes_alg(struct list_head *head,
328				const struct ccp_aes_def *def)
329{
330	struct ccp_crypto_ablkcipher_alg *ccp_alg;
331	struct crypto_alg *alg;
332	int ret;
333
334	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
335	if (!ccp_alg)
336		return -ENOMEM;
337
338	INIT_LIST_HEAD(&ccp_alg->entry);
339
340	ccp_alg->mode = def->mode;
341
342	/* Copy the defaults and override as necessary */
343	alg = &ccp_alg->alg;
344	memcpy(alg, def->alg_defaults, sizeof(*alg));
345	snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
346	snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
347		 def->driver_name);
348	alg->cra_blocksize = def->blocksize;
349	alg->cra_ablkcipher.ivsize = def->ivsize;
350
351	ret = crypto_register_alg(alg);
352	if (ret) {
353		pr_err("%s ablkcipher algorithm registration error (%d)\n",
354			alg->cra_name, ret);
355		kfree(ccp_alg);
356		return ret;
357	}
358
359	list_add(&ccp_alg->entry, head);
360
361	return 0;
362}
363
364int ccp_register_aes_algs(struct list_head *head)
365{
366	int i, ret;
367
368	for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
369		ret = ccp_register_aes_alg(head, &aes_algs[i]);
370		if (ret)
371			return ret;
372	}
373
374	return 0;
375}
376