2 * AMD Cryptographic Coprocessor (CCP) AES XTS crypto API support
4 * Copyright (C) 2013 Advanced Micro Devices, Inc.
6 * Author: Tom Lendacky <thomas.lendacky@amd.com>
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.
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/scatterwalk.h>
22 #include "ccp-crypto.h"
24 struct ccp_aes_xts_def {
29 static struct ccp_aes_xts_def aes_xts_algs[] = {
32 .drv_name = "xts-aes-ccp",
36 struct ccp_unit_size_map {
41 static struct ccp_unit_size_map unit_size_map[] = {
44 .value = CCP_XTS_AES_UNIT_SIZE_4096,
48 .value = CCP_XTS_AES_UNIT_SIZE_2048,
52 .value = CCP_XTS_AES_UNIT_SIZE_1024,
56 .value = CCP_XTS_AES_UNIT_SIZE_512,
60 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
64 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
68 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
72 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
76 .value = CCP_XTS_AES_UNIT_SIZE_16,
80 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
84 static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret)
86 struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
87 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
92 memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
97 static int ccp_aes_xts_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
100 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
102 /* Only support 128-bit AES key with a 128-bit Tweak key,
103 * otherwise use the fallback
106 case AES_KEYSIZE_128 * 2:
107 memcpy(ctx->u.aes.key, key, key_len);
110 ctx->u.aes.key_len = key_len / 2;
111 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
113 return crypto_ablkcipher_setkey(ctx->u.aes.tfm_ablkcipher, key,
117 static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
118 unsigned int encrypt)
120 struct crypto_tfm *tfm =
121 crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
122 struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
123 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
127 if (!ctx->u.aes.key_len)
130 if (req->nbytes & (AES_BLOCK_SIZE - 1))
136 for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++)
137 if (!(req->nbytes & (unit_size_map[unit].size - 1)))
140 if ((unit_size_map[unit].value == CCP_XTS_AES_UNIT_SIZE__LAST) ||
141 (ctx->u.aes.key_len != AES_KEYSIZE_128)) {
142 /* Use the fallback to process the request for any
143 * unsupported unit sizes or key sizes
145 ablkcipher_request_set_tfm(req, ctx->u.aes.tfm_ablkcipher);
146 ret = (encrypt) ? crypto_ablkcipher_encrypt(req) :
147 crypto_ablkcipher_decrypt(req);
148 ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
153 memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
154 sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE);
156 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
157 INIT_LIST_HEAD(&rctx->cmd.entry);
158 rctx->cmd.engine = CCP_ENGINE_XTS_AES_128;
159 rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
160 : CCP_AES_ACTION_DECRYPT;
161 rctx->cmd.u.xts.unit_size = unit_size_map[unit].value;
162 rctx->cmd.u.xts.key = &ctx->u.aes.key_sg;
163 rctx->cmd.u.xts.key_len = ctx->u.aes.key_len;
164 rctx->cmd.u.xts.iv = &rctx->iv_sg;
165 rctx->cmd.u.xts.iv_len = AES_BLOCK_SIZE;
166 rctx->cmd.u.xts.src = req->src;
167 rctx->cmd.u.xts.src_len = req->nbytes;
168 rctx->cmd.u.xts.dst = req->dst;
170 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
175 static int ccp_aes_xts_encrypt(struct ablkcipher_request *req)
177 return ccp_aes_xts_crypt(req, 1);
180 static int ccp_aes_xts_decrypt(struct ablkcipher_request *req)
182 return ccp_aes_xts_crypt(req, 0);
185 static int ccp_aes_xts_cra_init(struct crypto_tfm *tfm)
187 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
188 struct crypto_ablkcipher *fallback_tfm;
190 ctx->complete = ccp_aes_xts_complete;
191 ctx->u.aes.key_len = 0;
193 fallback_tfm = crypto_alloc_ablkcipher(crypto_tfm_alg_name(tfm), 0,
195 CRYPTO_ALG_NEED_FALLBACK);
196 if (IS_ERR(fallback_tfm)) {
197 pr_warn("could not load fallback driver %s\n",
198 crypto_tfm_alg_name(tfm));
199 return PTR_ERR(fallback_tfm);
201 ctx->u.aes.tfm_ablkcipher = fallback_tfm;
203 tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx) +
204 fallback_tfm->base.crt_ablkcipher.reqsize;
209 static void ccp_aes_xts_cra_exit(struct crypto_tfm *tfm)
211 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
213 if (ctx->u.aes.tfm_ablkcipher)
214 crypto_free_ablkcipher(ctx->u.aes.tfm_ablkcipher);
215 ctx->u.aes.tfm_ablkcipher = NULL;
218 static int ccp_register_aes_xts_alg(struct list_head *head,
219 const struct ccp_aes_xts_def *def)
221 struct ccp_crypto_ablkcipher_alg *ccp_alg;
222 struct crypto_alg *alg;
225 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
229 INIT_LIST_HEAD(&ccp_alg->entry);
233 snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
234 snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
236 alg->cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC |
237 CRYPTO_ALG_KERN_DRIVER_ONLY |
238 CRYPTO_ALG_NEED_FALLBACK;
239 alg->cra_blocksize = AES_BLOCK_SIZE;
240 alg->cra_ctxsize = sizeof(struct ccp_ctx);
241 alg->cra_priority = CCP_CRA_PRIORITY;
242 alg->cra_type = &crypto_ablkcipher_type;
243 alg->cra_ablkcipher.setkey = ccp_aes_xts_setkey;
244 alg->cra_ablkcipher.encrypt = ccp_aes_xts_encrypt;
245 alg->cra_ablkcipher.decrypt = ccp_aes_xts_decrypt;
246 alg->cra_ablkcipher.min_keysize = AES_MIN_KEY_SIZE * 2;
247 alg->cra_ablkcipher.max_keysize = AES_MAX_KEY_SIZE * 2;
248 alg->cra_ablkcipher.ivsize = AES_BLOCK_SIZE;
249 alg->cra_init = ccp_aes_xts_cra_init;
250 alg->cra_exit = ccp_aes_xts_cra_exit;
251 alg->cra_module = THIS_MODULE;
253 ret = crypto_register_alg(alg);
255 pr_err("%s ablkcipher algorithm registration error (%d)\n",
261 list_add(&ccp_alg->entry, head);
266 int ccp_register_aes_xts_algs(struct list_head *head)
270 for (i = 0; i < ARRAY_SIZE(aes_xts_algs); i++) {
271 ret = ccp_register_aes_xts_alg(head, &aes_xts_algs[i]);