Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * AMD Cryptographic Coprocessor (CCP) AES XTS crypto API support
4 *
5 * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
6 *
7 * Author: Gary R Hook <gary.hook@amd.com>
8 * Author: Tom Lendacky <thomas.lendacky@amd.com>
9 */
10
11#include <linux/module.h>
12#include <linux/sched.h>
13#include <linux/delay.h>
14#include <linux/scatterlist.h>
15#include <linux/string.h>
16#include <crypto/aes.h>
17#include <crypto/xts.h>
18#include <crypto/internal/skcipher.h>
19#include <crypto/scatterwalk.h>
20
21#include "ccp-crypto.h"
22
23struct ccp_aes_xts_def {
24 const char *name;
25 const char *drv_name;
26};
27
28static const struct ccp_aes_xts_def aes_xts_algs[] = {
29 {
30 .name = "xts(aes)",
31 .drv_name = "xts-aes-ccp",
32 },
33};
34
35struct ccp_unit_size_map {
36 unsigned int size;
37 u32 value;
38};
39
40static struct ccp_unit_size_map xts_unit_sizes[] = {
41 {
42 .size = 16,
43 .value = CCP_XTS_AES_UNIT_SIZE_16,
44 },
45 {
46 .size = 512,
47 .value = CCP_XTS_AES_UNIT_SIZE_512,
48 },
49 {
50 .size = 1024,
51 .value = CCP_XTS_AES_UNIT_SIZE_1024,
52 },
53 {
54 .size = 2048,
55 .value = CCP_XTS_AES_UNIT_SIZE_2048,
56 },
57 {
58 .size = 4096,
59 .value = CCP_XTS_AES_UNIT_SIZE_4096,
60 },
61};
62
63static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret)
64{
65 struct skcipher_request *req = skcipher_request_cast(async_req);
66 struct ccp_aes_req_ctx *rctx = skcipher_request_ctx_dma(req);
67
68 if (ret)
69 return ret;
70
71 memcpy(req->iv, rctx->iv, AES_BLOCK_SIZE);
72
73 return 0;
74}
75
76static int ccp_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
77 unsigned int key_len)
78{
79 struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
80 unsigned int ccpversion = ccp_version();
81 int ret;
82
83 ret = xts_verify_key(tfm, key, key_len);
84 if (ret)
85 return ret;
86
87 /* Version 3 devices support 128-bit keys; version 5 devices can
88 * accommodate 128- and 256-bit keys.
89 */
90 switch (key_len) {
91 case AES_KEYSIZE_128 * 2:
92 memcpy(ctx->u.aes.key, key, key_len);
93 break;
94 case AES_KEYSIZE_256 * 2:
95 if (ccpversion > CCP_VERSION(3, 0))
96 memcpy(ctx->u.aes.key, key, key_len);
97 break;
98 }
99 ctx->u.aes.key_len = key_len / 2;
100 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
101
102 return crypto_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len);
103}
104
105static int ccp_aes_xts_crypt(struct skcipher_request *req,
106 unsigned int encrypt)
107{
108 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
109 struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
110 struct ccp_aes_req_ctx *rctx = skcipher_request_ctx_dma(req);
111 unsigned int ccpversion = ccp_version();
112 unsigned int fallback = 0;
113 unsigned int unit;
114 u32 unit_size;
115 int ret;
116
117 if (!ctx->u.aes.key_len)
118 return -EINVAL;
119
120 if (!req->iv)
121 return -EINVAL;
122
123 /* Check conditions under which the CCP can fulfill a request. The
124 * device can handle input plaintext of a length that is a multiple
125 * of the unit_size, bug the crypto implementation only supports
126 * the unit_size being equal to the input length. This limits the
127 * number of scenarios we can handle.
128 */
129 unit_size = CCP_XTS_AES_UNIT_SIZE__LAST;
130 for (unit = 0; unit < ARRAY_SIZE(xts_unit_sizes); unit++) {
131 if (req->cryptlen == xts_unit_sizes[unit].size) {
132 unit_size = unit;
133 break;
134 }
135 }
136 /* The CCP has restrictions on block sizes. Also, a version 3 device
137 * only supports AES-128 operations; version 5 CCPs support both
138 * AES-128 and -256 operations.
139 */
140 if (unit_size == CCP_XTS_AES_UNIT_SIZE__LAST)
141 fallback = 1;
142 if ((ccpversion < CCP_VERSION(5, 0)) &&
143 (ctx->u.aes.key_len != AES_KEYSIZE_128))
144 fallback = 1;
145 if ((ctx->u.aes.key_len != AES_KEYSIZE_128) &&
146 (ctx->u.aes.key_len != AES_KEYSIZE_256))
147 fallback = 1;
148 if (fallback) {
149 /* Use the fallback to process the request for any
150 * unsupported unit sizes or key sizes
151 */
152 skcipher_request_set_tfm(&rctx->fallback_req,
153 ctx->u.aes.tfm_skcipher);
154 skcipher_request_set_callback(&rctx->fallback_req,
155 req->base.flags,
156 req->base.complete,
157 req->base.data);
158 skcipher_request_set_crypt(&rctx->fallback_req, req->src,
159 req->dst, req->cryptlen, req->iv);
160 ret = encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) :
161 crypto_skcipher_decrypt(&rctx->fallback_req);
162 return ret;
163 }
164
165 memcpy(rctx->iv, req->iv, AES_BLOCK_SIZE);
166 sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE);
167
168 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
169 INIT_LIST_HEAD(&rctx->cmd.entry);
170 rctx->cmd.engine = CCP_ENGINE_XTS_AES_128;
171 rctx->cmd.u.xts.type = CCP_AES_TYPE_128;
172 rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
173 : CCP_AES_ACTION_DECRYPT;
174 rctx->cmd.u.xts.unit_size = unit_size;
175 rctx->cmd.u.xts.key = &ctx->u.aes.key_sg;
176 rctx->cmd.u.xts.key_len = ctx->u.aes.key_len;
177 rctx->cmd.u.xts.iv = &rctx->iv_sg;
178 rctx->cmd.u.xts.iv_len = AES_BLOCK_SIZE;
179 rctx->cmd.u.xts.src = req->src;
180 rctx->cmd.u.xts.src_len = req->cryptlen;
181 rctx->cmd.u.xts.dst = req->dst;
182
183 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
184
185 return ret;
186}
187
188static int ccp_aes_xts_encrypt(struct skcipher_request *req)
189{
190 return ccp_aes_xts_crypt(req, 1);
191}
192
193static int ccp_aes_xts_decrypt(struct skcipher_request *req)
194{
195 return ccp_aes_xts_crypt(req, 0);
196}
197
198static int ccp_aes_xts_init_tfm(struct crypto_skcipher *tfm)
199{
200 struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
201 struct crypto_skcipher *fallback_tfm;
202
203 ctx->complete = ccp_aes_xts_complete;
204 ctx->u.aes.key_len = 0;
205
206 fallback_tfm = crypto_alloc_skcipher("xts(aes)", 0,
207 CRYPTO_ALG_NEED_FALLBACK);
208 if (IS_ERR(fallback_tfm)) {
209 pr_warn("could not load fallback driver xts(aes)\n");
210 return PTR_ERR(fallback_tfm);
211 }
212 ctx->u.aes.tfm_skcipher = fallback_tfm;
213
214 crypto_skcipher_set_reqsize_dma(tfm,
215 sizeof(struct ccp_aes_req_ctx) +
216 crypto_skcipher_reqsize(fallback_tfm));
217
218 return 0;
219}
220
221static void ccp_aes_xts_exit_tfm(struct crypto_skcipher *tfm)
222{
223 struct ccp_ctx *ctx = crypto_skcipher_ctx_dma(tfm);
224
225 crypto_free_skcipher(ctx->u.aes.tfm_skcipher);
226}
227
228static int ccp_register_aes_xts_alg(struct list_head *head,
229 const struct ccp_aes_xts_def *def)
230{
231 struct ccp_crypto_skcipher_alg *ccp_alg;
232 struct skcipher_alg *alg;
233 int ret;
234
235 ccp_alg = kzalloc_obj(*ccp_alg);
236 if (!ccp_alg)
237 return -ENOMEM;
238
239 INIT_LIST_HEAD(&ccp_alg->entry);
240
241 alg = &ccp_alg->alg;
242
243 strscpy(alg->base.cra_name, def->name);
244 strscpy(alg->base.cra_driver_name, def->drv_name);
245 alg->base.cra_flags = CRYPTO_ALG_ASYNC |
246 CRYPTO_ALG_ALLOCATES_MEMORY |
247 CRYPTO_ALG_KERN_DRIVER_ONLY |
248 CRYPTO_ALG_NEED_FALLBACK;
249 alg->base.cra_blocksize = AES_BLOCK_SIZE;
250 alg->base.cra_ctxsize = sizeof(struct ccp_ctx) +
251 crypto_dma_padding();
252 alg->base.cra_priority = CCP_CRA_PRIORITY;
253 alg->base.cra_module = THIS_MODULE;
254
255 alg->setkey = ccp_aes_xts_setkey;
256 alg->encrypt = ccp_aes_xts_encrypt;
257 alg->decrypt = ccp_aes_xts_decrypt;
258 alg->min_keysize = AES_MIN_KEY_SIZE * 2;
259 alg->max_keysize = AES_MAX_KEY_SIZE * 2;
260 alg->ivsize = AES_BLOCK_SIZE;
261 alg->init = ccp_aes_xts_init_tfm;
262 alg->exit = ccp_aes_xts_exit_tfm;
263
264 ret = crypto_register_skcipher(alg);
265 if (ret) {
266 pr_err("%s skcipher algorithm registration error (%d)\n",
267 alg->base.cra_name, ret);
268 kfree(ccp_alg);
269 return ret;
270 }
271
272 list_add(&ccp_alg->entry, head);
273
274 return 0;
275}
276
277int ccp_register_aes_xts_algs(struct list_head *head)
278{
279 int i, ret;
280
281 for (i = 0; i < ARRAY_SIZE(aes_xts_algs); i++) {
282 ret = ccp_register_aes_xts_alg(head, &aes_xts_algs[i]);
283 if (ret)
284 return ret;
285 }
286
287 return 0;
288}