ccp-crypto-aes.c

  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
 23static 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
 39static 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
 67static 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
111static int ccp_aes_encrypt(struct skcipher_request *req)
112{
113	return ccp_aes_crypt(req, true);
114}
115
116static int ccp_aes_decrypt(struct skcipher_request *req)
117{
118	return ccp_aes_crypt(req, false);
119}
120
121static 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
133static 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
145static 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
159static 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
183static int ccp_aes_rfc3686_encrypt(struct skcipher_request *req)
184{
185	return ccp_aes_rfc3686_crypt(req, true);
186}
187
188static int ccp_aes_rfc3686_decrypt(struct skcipher_request *req)
189{
190	return ccp_aes_rfc3686_crypt(req, false);
191}
192
193static 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
205static 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
223static 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
241struct 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
251static 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
290static 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
327int 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}