blob: c2374df9abae9c899434af6c591a95dd5e93d204 [file] [log] [blame]
/* Algorithms supported by virtio crypto device
*
* Authors: Gonglei <arei.gonglei@huawei.com>
*
* Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/scatterlist.h>
#include <crypto/algapi.h>
#include <linux/err.h>
#include <crypto/scatterwalk.h>
#include <linux/atomic.h>
#include <uapi/linux/virtio_crypto.h>
#include "virtio_crypto_common.h"
/*
* The algs_lock protects the below global virtio_crypto_active_devs
* and crypto algorithms registion.
*/
static DEFINE_MUTEX(algs_lock);
static unsigned int virtio_crypto_active_devs;
static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg)
{
u64 total = 0;
for (total = 0; sg; sg = sg_next(sg))
total += sg->length;
return total;
}
static int
virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
{
switch (key_len) {
case AES_KEYSIZE_128:
case AES_KEYSIZE_192:
case AES_KEYSIZE_256:
*alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
break;
default:
pr_err("virtio_crypto: Unsupported key length: %d\n",
key_len);
return -EINVAL;
}
return 0;
}
static int virtio_crypto_alg_ablkcipher_init_session(
struct virtio_crypto_ablkcipher_ctx *ctx,
uint32_t alg, const uint8_t *key,
unsigned int keylen,
int encrypt)
{
struct scatterlist outhdr, key_sg, inhdr, *sgs[3];
unsigned int tmp;
struct virtio_crypto *vcrypto = ctx->vcrypto;
int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT;
int err;
unsigned int num_out = 0, num_in = 0;
/*
* Avoid to do DMA from the stack, switch to using
* dynamically-allocated for the key
*/
uint8_t *cipher_key = kmalloc(keylen, GFP_ATOMIC);
if (!cipher_key)
return -ENOMEM;
memcpy(cipher_key, key, keylen);
spin_lock(&vcrypto->ctrl_lock);
/* Pad ctrl header */
vcrypto->ctrl.header.opcode =
cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
vcrypto->ctrl.header.algo = cpu_to_le32(alg);
/* Set the default dataqueue id to 0 */
vcrypto->ctrl.header.queue_id = 0;
vcrypto->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
/* Pad cipher's parameters */
vcrypto->ctrl.u.sym_create_session.op_type =
cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
vcrypto->ctrl.u.sym_create_session.u.cipher.para.algo =
vcrypto->ctrl.header.algo;
vcrypto->ctrl.u.sym_create_session.u.cipher.para.keylen =
cpu_to_le32(keylen);
vcrypto->ctrl.u.sym_create_session.u.cipher.para.op =
cpu_to_le32(op);
sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
sgs[num_out++] = &outhdr;
/* Set key */
sg_init_one(&key_sg, cipher_key, keylen);
sgs[num_out++] = &key_sg;
/* Return status and session id back */
sg_init_one(&inhdr, &vcrypto->input, sizeof(vcrypto->input));
sgs[num_out + num_in++] = &inhdr;
err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
num_in, vcrypto, GFP_ATOMIC);
if (err < 0) {
spin_unlock(&vcrypto->ctrl_lock);
kzfree(cipher_key);
return err;
}
virtqueue_kick(vcrypto->ctrl_vq);
/*
* Trapping into the hypervisor, so the request should be
* handled immediately.
*/
while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
!virtqueue_is_broken(vcrypto->ctrl_vq))
cpu_relax();
if (le32_to_cpu(vcrypto->input.status) != VIRTIO_CRYPTO_OK) {
spin_unlock(&vcrypto->ctrl_lock);
pr_err("virtio_crypto: Create session failed status: %u\n",
le32_to_cpu(vcrypto->input.status));
kzfree(cipher_key);
return -EINVAL;
}
if (encrypt)
ctx->enc_sess_info.session_id =
le64_to_cpu(vcrypto->input.session_id);
else
ctx->dec_sess_info.session_id =
le64_to_cpu(vcrypto->input.session_id);
spin_unlock(&vcrypto->ctrl_lock);
kzfree(cipher_key);
return 0;
}
static int virtio_crypto_alg_ablkcipher_close_session(
struct virtio_crypto_ablkcipher_ctx *ctx,
int encrypt)
{
struct scatterlist outhdr, status_sg, *sgs[2];
unsigned int tmp;
struct virtio_crypto_destroy_session_req *destroy_session;
struct virtio_crypto *vcrypto = ctx->vcrypto;
int err;
unsigned int num_out = 0, num_in = 0;
spin_lock(&vcrypto->ctrl_lock);
vcrypto->ctrl_status.status = VIRTIO_CRYPTO_ERR;
/* Pad ctrl header */
vcrypto->ctrl.header.opcode =
cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
/* Set the default virtqueue id to 0 */
vcrypto->ctrl.header.queue_id = 0;
destroy_session = &vcrypto->ctrl.u.destroy_session;
if (encrypt)
destroy_session->session_id =
cpu_to_le64(ctx->enc_sess_info.session_id);
else
destroy_session->session_id =
cpu_to_le64(ctx->dec_sess_info.session_id);
sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
sgs[num_out++] = &outhdr;
/* Return status and session id back */
sg_init_one(&status_sg, &vcrypto->ctrl_status.status,
sizeof(vcrypto->ctrl_status.status));
sgs[num_out + num_in++] = &status_sg;
err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
num_in, vcrypto, GFP_ATOMIC);
if (err < 0) {
spin_unlock(&vcrypto->ctrl_lock);
return err;
}
virtqueue_kick(vcrypto->ctrl_vq);
while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
!virtqueue_is_broken(vcrypto->ctrl_vq))
cpu_relax();
if (vcrypto->ctrl_status.status != VIRTIO_CRYPTO_OK) {
spin_unlock(&vcrypto->ctrl_lock);
pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
vcrypto->ctrl_status.status,
destroy_session->session_id);
return -EINVAL;
}
spin_unlock(&vcrypto->ctrl_lock);
return 0;
}
static int virtio_crypto_alg_ablkcipher_init_sessions(
struct virtio_crypto_ablkcipher_ctx *ctx,
const uint8_t *key, unsigned int keylen)
{
uint32_t alg;
int ret;
struct virtio_crypto *vcrypto = ctx->vcrypto;
if (keylen > vcrypto->max_cipher_key_len) {
pr_err("virtio_crypto: the key is too long\n");
goto bad_key;
}
if (virtio_crypto_alg_validate_key(keylen, &alg))
goto bad_key;
/* Create encryption session */
ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
alg, key, keylen, 1);
if (ret)
return ret;
/* Create decryption session */
ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
alg, key, keylen, 0);
if (ret) {
virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
return ret;
}
return 0;
bad_key:
crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
/* Note: kernel crypto API realization */
static int virtio_crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm,
const uint8_t *key,
unsigned int keylen)
{
struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
int ret;
if (!ctx->vcrypto) {
/* New key */
int node = virtio_crypto_get_current_node();
struct virtio_crypto *vcrypto =
virtcrypto_get_dev_node(node);
if (!vcrypto) {
pr_err("virtio_crypto: Could not find a virtio device in the system");
return -ENODEV;
}
ctx->vcrypto = vcrypto;
} else {
/* Rekeying, we should close the created sessions previously */
virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
}
ret = virtio_crypto_alg_ablkcipher_init_sessions(ctx, key, keylen);
if (ret) {
virtcrypto_dev_put(ctx->vcrypto);
ctx->vcrypto = NULL;
return ret;
}
return 0;
}
static int
__virtio_crypto_ablkcipher_do_req(struct virtio_crypto_request *vc_req,
struct ablkcipher_request *req,
struct data_queue *data_vq,
__u8 op)
{
struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
unsigned int ivsize = crypto_ablkcipher_ivsize(tfm);
struct virtio_crypto_ablkcipher_ctx *ctx = vc_req->ablkcipher_ctx;
struct virtio_crypto *vcrypto = ctx->vcrypto;
struct virtio_crypto_op_data_req *req_data;
int src_nents, dst_nents;
int err;
unsigned long flags;
struct scatterlist outhdr, iv_sg, status_sg, **sgs;
int i;
u64 dst_len;
unsigned int num_out = 0, num_in = 0;
int sg_total;
uint8_t *iv;
src_nents = sg_nents_for_len(req->src, req->nbytes);
dst_nents = sg_nents(req->dst);
pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
src_nents, dst_nents);
/* Why 3? outhdr + iv + inhdr */
sg_total = src_nents + dst_nents + 3;
sgs = kzalloc_node(sg_total * sizeof(*sgs), GFP_ATOMIC,
dev_to_node(&vcrypto->vdev->dev));
if (!sgs)
return -ENOMEM;
req_data = kzalloc_node(sizeof(*req_data), GFP_ATOMIC,
dev_to_node(&vcrypto->vdev->dev));
if (!req_data) {
kfree(sgs);
return -ENOMEM;
}
vc_req->req_data = req_data;
vc_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
/* Head of operation */
if (op) {
req_data->header.session_id =
cpu_to_le64(ctx->enc_sess_info.session_id);
req_data->header.opcode =
cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT);
} else {
req_data->header.session_id =
cpu_to_le64(ctx->dec_sess_info.session_id);
req_data->header.opcode =
cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT);
}
req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize);
req_data->u.sym_req.u.cipher.para.src_data_len =
cpu_to_le32(req->nbytes);
dst_len = virtio_crypto_alg_sg_nents_length(req->dst);
if (unlikely(dst_len > U32_MAX)) {
pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n");
err = -EINVAL;
goto free;
}
pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
req->nbytes, dst_len);
if (unlikely(req->nbytes + dst_len + ivsize +
sizeof(vc_req->status) > vcrypto->max_size)) {
pr_err("virtio_crypto: The length is too big\n");
err = -EINVAL;
goto free;
}
req_data->u.sym_req.u.cipher.para.dst_data_len =
cpu_to_le32((uint32_t)dst_len);
/* Outhdr */
sg_init_one(&outhdr, req_data, sizeof(*req_data));
sgs[num_out++] = &outhdr;
/* IV */
/*
* Avoid to do DMA from the stack, switch to using
* dynamically-allocated for the IV
*/
iv = kzalloc_node(ivsize, GFP_ATOMIC,
dev_to_node(&vcrypto->vdev->dev));
if (!iv) {
err = -ENOMEM;
goto free;
}
memcpy(iv, req->info, ivsize);
sg_init_one(&iv_sg, iv, ivsize);
sgs[num_out++] = &iv_sg;
vc_req->iv = iv;
/* Source data */
for (i = 0; i < src_nents; i++)
sgs[num_out++] = &req->src[i];
/* Destination data */
for (i = 0; i < dst_nents; i++)
sgs[num_out + num_in++] = &req->dst[i];
/* Status */
sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
sgs[num_out + num_in++] = &status_sg;
vc_req->sgs = sgs;
spin_lock_irqsave(&data_vq->lock, flags);
err = virtqueue_add_sgs(data_vq->vq, sgs, num_out,
num_in, vc_req, GFP_ATOMIC);
virtqueue_kick(data_vq->vq);
spin_unlock_irqrestore(&data_vq->lock, flags);
if (unlikely(err < 0))
goto free_iv;
return 0;
free_iv:
kzfree(iv);
free:
kzfree(req_data);
kfree(sgs);
return err;
}
static int virtio_crypto_ablkcipher_encrypt(struct ablkcipher_request *req)
{
struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
struct virtio_crypto_request *vc_req = ablkcipher_request_ctx(req);
struct virtio_crypto *vcrypto = ctx->vcrypto;
int ret;
/* Use the first data virtqueue as default */
struct data_queue *data_vq = &vcrypto->data_vq[0];
vc_req->ablkcipher_ctx = ctx;
vc_req->ablkcipher_req = req;
ret = __virtio_crypto_ablkcipher_do_req(vc_req, req, data_vq, 1);
if (ret < 0) {
pr_err("virtio_crypto: Encryption failed!\n");
return ret;
}
return -EINPROGRESS;
}
static int virtio_crypto_ablkcipher_decrypt(struct ablkcipher_request *req)
{
struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
struct virtio_crypto_request *vc_req = ablkcipher_request_ctx(req);
struct virtio_crypto *vcrypto = ctx->vcrypto;
int ret;
/* Use the first data virtqueue as default */
struct data_queue *data_vq = &vcrypto->data_vq[0];
vc_req->ablkcipher_ctx = ctx;
vc_req->ablkcipher_req = req;
ret = __virtio_crypto_ablkcipher_do_req(vc_req, req, data_vq, 0);
if (ret < 0) {
pr_err("virtio_crypto: Decryption failed!\n");
return ret;
}
return -EINPROGRESS;
}
static int virtio_crypto_ablkcipher_init(struct crypto_tfm *tfm)
{
struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
tfm->crt_ablkcipher.reqsize = sizeof(struct virtio_crypto_request);
ctx->tfm = tfm;
return 0;
}
static void virtio_crypto_ablkcipher_exit(struct crypto_tfm *tfm)
{
struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
if (!ctx->vcrypto)
return;
virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
virtcrypto_dev_put(ctx->vcrypto);
ctx->vcrypto = NULL;
}
static struct crypto_alg virtio_crypto_algs[] = { {
.cra_name = "cbc(aes)",
.cra_driver_name = "virtio_crypto_aes_cbc",
.cra_priority = 501,
.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct virtio_crypto_ablkcipher_ctx),
.cra_alignmask = 0,
.cra_module = THIS_MODULE,
.cra_type = &crypto_ablkcipher_type,
.cra_init = virtio_crypto_ablkcipher_init,
.cra_exit = virtio_crypto_ablkcipher_exit,
.cra_u = {
.ablkcipher = {
.setkey = virtio_crypto_ablkcipher_setkey,
.decrypt = virtio_crypto_ablkcipher_decrypt,
.encrypt = virtio_crypto_ablkcipher_encrypt,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
},
},
} };
int virtio_crypto_algs_register(void)
{
int ret = 0;
mutex_lock(&algs_lock);
if (++virtio_crypto_active_devs != 1)
goto unlock;
ret = crypto_register_algs(virtio_crypto_algs,
ARRAY_SIZE(virtio_crypto_algs));
if (ret)
virtio_crypto_active_devs--;
unlock:
mutex_unlock(&algs_lock);
return ret;
}
void virtio_crypto_algs_unregister(void)
{
mutex_lock(&algs_lock);
if (--virtio_crypto_active_devs != 0)
goto unlock;
crypto_unregister_algs(virtio_crypto_algs,
ARRAY_SIZE(virtio_crypto_algs));
unlock:
mutex_unlock(&algs_lock);
}