1 // SPDX-License-Identifier: GPL-2.0-only
3 * AMD Cryptographic Coprocessor (CCP) AES XTS crypto API support
5 * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
7 * Author: Gary R Hook <gary.hook@amd.com>
8 * Author: Tom Lendacky <thomas.lendacky@amd.com>
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/delay.h>
14 #include <linux/scatterlist.h>
15 #include <crypto/aes.h>
16 #include <crypto/xts.h>
17 #include <crypto/internal/skcipher.h>
18 #include <crypto/scatterwalk.h>
20 #include "ccp-crypto.h"
22 struct ccp_aes_xts_def {
27 static struct ccp_aes_xts_def aes_xts_algs[] = {
30 .drv_name = "xts-aes-ccp",
34 struct ccp_unit_size_map {
39 static struct ccp_unit_size_map xts_unit_sizes[] = {
42 .value = CCP_XTS_AES_UNIT_SIZE_16,
46 .value = CCP_XTS_AES_UNIT_SIZE_512,
50 .value = CCP_XTS_AES_UNIT_SIZE_1024,
54 .value = CCP_XTS_AES_UNIT_SIZE_2048,
58 .value = CCP_XTS_AES_UNIT_SIZE_4096,
62 static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret)
64 struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
65 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
70 memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
75 static int ccp_aes_xts_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
78 struct crypto_tfm *xfm = crypto_ablkcipher_tfm(tfm);
79 struct ccp_ctx *ctx = crypto_tfm_ctx(xfm);
80 unsigned int ccpversion = ccp_version();
83 ret = xts_check_key(xfm, key, key_len);
87 /* Version 3 devices support 128-bit keys; version 5 devices can
88 * accommodate 128- and 256-bit keys.
91 case AES_KEYSIZE_128 * 2:
92 memcpy(ctx->u.aes.key, key, key_len);
94 case AES_KEYSIZE_256 * 2:
95 if (ccpversion > CCP_VERSION(3, 0))
96 memcpy(ctx->u.aes.key, key, key_len);
99 ctx->u.aes.key_len = key_len / 2;
100 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
102 return crypto_sync_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len);
105 static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
106 unsigned int encrypt)
108 struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
109 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
110 unsigned int ccpversion = ccp_version();
111 unsigned int fallback = 0;
116 if (!ctx->u.aes.key_len)
122 /* Check conditions under which the CCP can fulfill a request. The
123 * device can handle input plaintext of a length that is a multiple
124 * of the unit_size, bug the crypto implementation only supports
125 * the unit_size being equal to the input length. This limits the
126 * number of scenarios we can handle.
128 unit_size = CCP_XTS_AES_UNIT_SIZE__LAST;
129 for (unit = 0; unit < ARRAY_SIZE(xts_unit_sizes); unit++) {
130 if (req->nbytes == xts_unit_sizes[unit].size) {
135 /* The CCP has restrictions on block sizes. Also, a version 3 device
136 * only supports AES-128 operations; version 5 CCPs support both
137 * AES-128 and -256 operations.
139 if (unit_size == CCP_XTS_AES_UNIT_SIZE__LAST)
141 if ((ccpversion < CCP_VERSION(5, 0)) &&
142 (ctx->u.aes.key_len != AES_KEYSIZE_128))
144 if ((ctx->u.aes.key_len != AES_KEYSIZE_128) &&
145 (ctx->u.aes.key_len != AES_KEYSIZE_256))
148 SYNC_SKCIPHER_REQUEST_ON_STACK(subreq,
149 ctx->u.aes.tfm_skcipher);
151 /* Use the fallback to process the request for any
152 * unsupported unit sizes or key sizes
154 skcipher_request_set_sync_tfm(subreq, ctx->u.aes.tfm_skcipher);
155 skcipher_request_set_callback(subreq, req->base.flags,
157 skcipher_request_set_crypt(subreq, req->src, req->dst,
158 req->nbytes, req->info);
159 ret = encrypt ? crypto_skcipher_encrypt(subreq) :
160 crypto_skcipher_decrypt(subreq);
161 skcipher_request_zero(subreq);
165 memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
166 sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE);
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->nbytes;
181 rctx->cmd.u.xts.dst = req->dst;
183 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
188 static int ccp_aes_xts_encrypt(struct ablkcipher_request *req)
190 return ccp_aes_xts_crypt(req, 1);
193 static int ccp_aes_xts_decrypt(struct ablkcipher_request *req)
195 return ccp_aes_xts_crypt(req, 0);
198 static int ccp_aes_xts_cra_init(struct crypto_tfm *tfm)
200 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
201 struct crypto_sync_skcipher *fallback_tfm;
203 ctx->complete = ccp_aes_xts_complete;
204 ctx->u.aes.key_len = 0;
206 fallback_tfm = crypto_alloc_sync_skcipher("xts(aes)", 0,
208 CRYPTO_ALG_NEED_FALLBACK);
209 if (IS_ERR(fallback_tfm)) {
210 pr_warn("could not load fallback driver xts(aes)\n");
211 return PTR_ERR(fallback_tfm);
213 ctx->u.aes.tfm_skcipher = fallback_tfm;
215 tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx);
220 static void ccp_aes_xts_cra_exit(struct crypto_tfm *tfm)
222 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
224 crypto_free_sync_skcipher(ctx->u.aes.tfm_skcipher);
227 static int ccp_register_aes_xts_alg(struct list_head *head,
228 const struct ccp_aes_xts_def *def)
230 struct ccp_crypto_ablkcipher_alg *ccp_alg;
231 struct crypto_alg *alg;
234 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
238 INIT_LIST_HEAD(&ccp_alg->entry);
242 snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
243 snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
245 alg->cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC |
246 CRYPTO_ALG_KERN_DRIVER_ONLY |
247 CRYPTO_ALG_NEED_FALLBACK;
248 alg->cra_blocksize = AES_BLOCK_SIZE;
249 alg->cra_ctxsize = sizeof(struct ccp_ctx);
250 alg->cra_priority = CCP_CRA_PRIORITY;
251 alg->cra_type = &crypto_ablkcipher_type;
252 alg->cra_ablkcipher.setkey = ccp_aes_xts_setkey;
253 alg->cra_ablkcipher.encrypt = ccp_aes_xts_encrypt;
254 alg->cra_ablkcipher.decrypt = ccp_aes_xts_decrypt;
255 alg->cra_ablkcipher.min_keysize = AES_MIN_KEY_SIZE * 2;
256 alg->cra_ablkcipher.max_keysize = AES_MAX_KEY_SIZE * 2;
257 alg->cra_ablkcipher.ivsize = AES_BLOCK_SIZE;
258 alg->cra_init = ccp_aes_xts_cra_init;
259 alg->cra_exit = ccp_aes_xts_cra_exit;
260 alg->cra_module = THIS_MODULE;
262 ret = crypto_register_alg(alg);
264 pr_err("%s ablkcipher algorithm registration error (%d)\n",
270 list_add(&ccp_alg->entry, head);
275 int ccp_register_aes_xts_algs(struct list_head *head)
279 for (i = 0; i < ARRAY_SIZE(aes_xts_algs); i++) {
280 ret = ccp_register_aes_xts_alg(head, &aes_xts_algs[i]);