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// SPDX-License-Identifier: GPL-2.0-only
/*
* AMD Cryptographic Coprocessor (CCP) AES XTS crypto API support
*
* Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
*
* Author: Gary R Hook <gary.hook@amd.com>
* Author: Tom Lendacky <thomas.lendacky@amd.com>
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/scatterlist.h>
#include <crypto/aes.h>
#include <crypto/xts.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include "ccp-crypto.h"
struct ccp_aes_xts_def {
const char *name;
const char *drv_name;
};
static const struct ccp_aes_xts_def aes_xts_algs[] = {
{
.name = "xts(aes)",
.drv_name = "xts-aes-ccp",
},
};
struct ccp_unit_size_map {
unsigned int size;
u32 value;
};
static struct ccp_unit_size_map xts_unit_sizes[] = {
{
.size = 16,
.value = CCP_XTS_AES_UNIT_SIZE_16,
},
{
.size = 512,
.value = CCP_XTS_AES_UNIT_SIZE_512,
},
{
.size = 1024,
.value = CCP_XTS_AES_UNIT_SIZE_1024,
},
{
.size = 2048,
.value = CCP_XTS_AES_UNIT_SIZE_2048,
},
{
.size = 4096,
.value = CCP_XTS_AES_UNIT_SIZE_4096,
},
};
static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret)
{
struct skcipher_request *req = skcipher_request_cast(async_req);
struct ccp_aes_req_ctx *rctx = skcipher_request_ctx(req);
if (ret)
return ret;
memcpy(req->iv, rctx->iv, AES_BLOCK_SIZE);
return 0;
}
static int ccp_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int key_len)
{
struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
unsigned int ccpversion = ccp_version();
int ret;
ret = xts_verify_key(tfm, key, key_len);
if (ret)
return ret;
/* Version 3 devices support 128-bit keys; version 5 devices can
* accommodate 128- and 256-bit keys.
*/
switch (key_len) {
case AES_KEYSIZE_128 * 2:
memcpy(ctx->u.aes.key, key, key_len);
break;
case AES_KEYSIZE_256 * 2:
if (ccpversion > CCP_VERSION(3, 0))
memcpy(ctx->u.aes.key, key, key_len);
break;
}
ctx->u.aes.key_len = key_len / 2;
sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
return crypto_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len);
}
static int ccp_aes_xts_crypt(struct skcipher_request *req,
unsigned int encrypt)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
struct ccp_aes_req_ctx *rctx = skcipher_request_ctx(req);
unsigned int ccpversion = ccp_version();
unsigned int fallback = 0;
unsigned int unit;
u32 unit_size;
int ret;
if (!ctx->u.aes.key_len)
return -EINVAL;
if (!req->iv)
return -EINVAL;
/* Check conditions under which the CCP can fulfill a request. The
* device can handle input plaintext of a length that is a multiple
* of the unit_size, bug the crypto implementation only supports
* the unit_size being equal to the input length. This limits the
* number of scenarios we can handle.
*/
unit_size = CCP_XTS_AES_UNIT_SIZE__LAST;
for (unit = 0; unit < ARRAY_SIZE(xts_unit_sizes); unit++) {
if (req->cryptlen == xts_unit_sizes[unit].size) {
unit_size = unit;
break;
}
}
/* The CCP has restrictions on block sizes. Also, a version 3 device
* only supports AES-128 operations; version 5 CCPs support both
* AES-128 and -256 operations.
*/
if (unit_size == CCP_XTS_AES_UNIT_SIZE__LAST)
fallback = 1;
if ((ccpversion < CCP_VERSION(5, 0)) &&
(ctx->u.aes.key_len != AES_KEYSIZE_128))
fallback = 1;
if ((ctx->u.aes.key_len != AES_KEYSIZE_128) &&
(ctx->u.aes.key_len != AES_KEYSIZE_256))
fallback = 1;
if (fallback) {
/* Use the fallback to process the request for any
* unsupported unit sizes or key sizes
*/
skcipher_request_set_tfm(&rctx->fallback_req,
ctx->u.aes.tfm_skcipher);
skcipher_request_set_callback(&rctx->fallback_req,
req->base.flags,
req->base.complete,
req->base.data);
skcipher_request_set_crypt(&rctx->fallback_req, req->src,
req->dst, req->cryptlen, req->iv);
ret = encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) :
crypto_skcipher_decrypt(&rctx->fallback_req);
return ret;
}
memcpy(rctx->iv, req->iv, AES_BLOCK_SIZE);
sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE);
memset(&rctx->cmd, 0, sizeof(rctx->cmd));
INIT_LIST_HEAD(&rctx->cmd.entry);
rctx->cmd.engine = CCP_ENGINE_XTS_AES_128;
rctx->cmd.u.xts.type = CCP_AES_TYPE_128;
rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
: CCP_AES_ACTION_DECRYPT;
rctx->cmd.u.xts.unit_size = unit_size;
rctx->cmd.u.xts.key = &ctx->u.aes.key_sg;
rctx->cmd.u.xts.key_len = ctx->u.aes.key_len;
rctx->cmd.u.xts.iv = &rctx->iv_sg;
rctx->cmd.u.xts.iv_len = AES_BLOCK_SIZE;
rctx->cmd.u.xts.src = req->src;
rctx->cmd.u.xts.src_len = req->cryptlen;
rctx->cmd.u.xts.dst = req->dst;
ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
return ret;
}
static int ccp_aes_xts_encrypt(struct skcipher_request *req)
{
return ccp_aes_xts_crypt(req, 1);
}
static int ccp_aes_xts_decrypt(struct skcipher_request *req)
{
return ccp_aes_xts_crypt(req, 0);
}
static int ccp_aes_xts_init_tfm(struct crypto_skcipher *tfm)
{
struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *fallback_tfm;
ctx->complete = ccp_aes_xts_complete;
ctx->u.aes.key_len = 0;
fallback_tfm = crypto_alloc_skcipher("xts(aes)", 0,
CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback_tfm)) {
pr_warn("could not load fallback driver xts(aes)\n");
return PTR_ERR(fallback_tfm);
}
ctx->u.aes.tfm_skcipher = fallback_tfm;
crypto_skcipher_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx) +
crypto_skcipher_reqsize(fallback_tfm));
return 0;
}
static void ccp_aes_xts_exit_tfm(struct crypto_skcipher *tfm)
{
struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
crypto_free_skcipher(ctx->u.aes.tfm_skcipher);
}
static int ccp_register_aes_xts_alg(struct list_head *head,
const struct ccp_aes_xts_def *def)
{
struct ccp_crypto_skcipher_alg *ccp_alg;
struct skcipher_alg *alg;
int ret;
ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
if (!ccp_alg)
return -ENOMEM;
INIT_LIST_HEAD(&ccp_alg->entry);
alg = &ccp_alg->alg;
snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
def->drv_name);
alg->base.cra_flags = CRYPTO_ALG_ASYNC |
CRYPTO_ALG_ALLOCATES_MEMORY |
CRYPTO_ALG_KERN_DRIVER_ONLY |
CRYPTO_ALG_NEED_FALLBACK;
alg->base.cra_blocksize = AES_BLOCK_SIZE;
alg->base.cra_ctxsize = sizeof(struct ccp_ctx);
alg->base.cra_priority = CCP_CRA_PRIORITY;
alg->base.cra_module = THIS_MODULE;
alg->setkey = ccp_aes_xts_setkey;
alg->encrypt = ccp_aes_xts_encrypt;
alg->decrypt = ccp_aes_xts_decrypt;
alg->min_keysize = AES_MIN_KEY_SIZE * 2;
alg->max_keysize = AES_MAX_KEY_SIZE * 2;
alg
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