qemu/backends/cryptodev-lkcf.c
Lei He 39fff6f3e8 cryptodev: Add a lkcf-backend for cryptodev
cryptodev: Added a new type of backend named lkcf-backend for
cryptodev. This backend upload asymmetric keys to linux kernel,
and let kernel do the accelerations if possible.
The lkcf stands for Linux Kernel Cryptography Framework.

Signed-off-by: lei he <helei.sig11@bytedance.com>
Message-Id: <20221008085030.70212-5-helei.sig11@bytedance.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-11-02 06:56:32 -04:00

646 lines
20 KiB
C

/*
* QEMU Cryptodev backend for QEMU cipher APIs
*
* Copyright (c) 2022 Bytedance.Inc
*
* Authors:
* lei he <helei.sig11@bytedance.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "crypto/cipher.h"
#include "crypto/akcipher.h"
#include "qapi/error.h"
#include "qemu/main-loop.h"
#include "qemu/thread.h"
#include "qemu/error-report.h"
#include "qemu/queue.h"
#include "qom/object.h"
#include "sysemu/cryptodev.h"
#include "standard-headers/linux/virtio_crypto.h"
#include <keyutils.h>
#include <sys/eventfd.h>
/**
* @TYPE_CRYPTODEV_BACKEND_LKCF:
* name of backend that uses linux kernel crypto framework
*/
#define TYPE_CRYPTODEV_BACKEND_LKCF "cryptodev-backend-lkcf"
OBJECT_DECLARE_SIMPLE_TYPE(CryptoDevBackendLKCF, CRYPTODEV_BACKEND_LKCF)
#define INVALID_KEY_ID -1
#define MAX_SESSIONS 256
#define NR_WORKER_THREAD 64
#define KCTL_KEY_TYPE_PKEY "asymmetric"
/**
* Here the key is uploaded to the thread-keyring of worker thread, at least
* util linux-6.0:
* 1. process keyring seems to behave unexpectedly if main-thread does not
* create the keyring before creating any other thread.
* 2. at present, the guest kernel never perform multiple operations on a
* session.
* 3. it can reduce the load of the main-loop because the key passed by the
* guest kernel has been already checked.
*/
#define KCTL_KEY_RING KEY_SPEC_THREAD_KEYRING
typedef struct CryptoDevBackendLKCFSession {
uint8_t *key;
size_t keylen;
QCryptoAkCipherKeyType keytype;
QCryptoAkCipherOptions akcipher_opts;
} CryptoDevBackendLKCFSession;
typedef struct CryptoDevBackendLKCF CryptoDevBackendLKCF;
typedef struct CryptoDevLKCFTask CryptoDevLKCFTask;
struct CryptoDevLKCFTask {
CryptoDevBackendLKCFSession *sess;
CryptoDevBackendOpInfo *op_info;
CryptoDevCompletionFunc cb;
void *opaque;
int status;
CryptoDevBackendLKCF *lkcf;
QSIMPLEQ_ENTRY(CryptoDevLKCFTask) queue;
};
typedef struct CryptoDevBackendLKCF {
CryptoDevBackend parent_obj;
CryptoDevBackendLKCFSession *sess[MAX_SESSIONS];
QSIMPLEQ_HEAD(, CryptoDevLKCFTask) requests;
QSIMPLEQ_HEAD(, CryptoDevLKCFTask) responses;
QemuMutex mutex;
QemuCond cond;
QemuMutex rsp_mutex;
/**
* There is no async interface for asymmetric keys like AF_ALG sockets,
* we don't seem to have better way than create a lots of thread.
*/
QemuThread worker_threads[NR_WORKER_THREAD];
bool running;
int eventfd;
} CryptoDevBackendLKCF;
static void *cryptodev_lkcf_worker(void *arg);
static int cryptodev_lkcf_close_session(CryptoDevBackend *backend,
uint64_t session_id,
uint32_t queue_index,
CryptoDevCompletionFunc cb,
void *opaque);
static void cryptodev_lkcf_handle_response(void *opaque)
{
CryptoDevBackendLKCF *lkcf = (CryptoDevBackendLKCF *)opaque;
QSIMPLEQ_HEAD(, CryptoDevLKCFTask) responses;
CryptoDevLKCFTask *task, *next;
eventfd_t nevent;
QSIMPLEQ_INIT(&responses);
eventfd_read(lkcf->eventfd, &nevent);
qemu_mutex_lock(&lkcf->rsp_mutex);
QSIMPLEQ_PREPEND(&responses, &lkcf->responses);
qemu_mutex_unlock(&lkcf->rsp_mutex);
QSIMPLEQ_FOREACH_SAFE(task, &responses, queue, next) {
if (task->cb) {
task->cb(task->opaque, task->status);
}
g_free(task);
}
}
static int cryptodev_lkcf_set_op_desc(QCryptoAkCipherOptions *opts,
char *key_desc,
size_t desc_len,
Error **errp)
{
QCryptoAkCipherOptionsRSA *rsa_opt;
if (opts->alg != QCRYPTO_AKCIPHER_ALG_RSA) {
error_setg(errp, "Unsupported alg: %u", opts->alg);
return -1;
}
rsa_opt = &opts->u.rsa;
if (rsa_opt->padding_alg == QCRYPTO_RSA_PADDING_ALG_PKCS1) {
snprintf(key_desc, desc_len, "enc=%s hash=%s",
QCryptoRSAPaddingAlgorithm_str(rsa_opt->padding_alg),
QCryptoHashAlgorithm_str(rsa_opt->hash_alg));
} else {
snprintf(key_desc, desc_len, "enc=%s",
QCryptoRSAPaddingAlgorithm_str(rsa_opt->padding_alg));
}
return 0;
}
static int cryptodev_lkcf_set_rsa_opt(int virtio_padding_alg,
int virtio_hash_alg,
QCryptoAkCipherOptionsRSA *opt,
Error **errp)
{
if (virtio_padding_alg == VIRTIO_CRYPTO_RSA_PKCS1_PADDING) {
opt->padding_alg = QCRYPTO_RSA_PADDING_ALG_PKCS1;
switch (virtio_hash_alg) {
case VIRTIO_CRYPTO_RSA_MD5:
opt->hash_alg = QCRYPTO_HASH_ALG_MD5;
break;
case VIRTIO_CRYPTO_RSA_SHA1:
opt->hash_alg = QCRYPTO_HASH_ALG_SHA1;
break;
case VIRTIO_CRYPTO_RSA_SHA256:
opt->hash_alg = QCRYPTO_HASH_ALG_SHA256;
break;
case VIRTIO_CRYPTO_RSA_SHA512:
opt->hash_alg = QCRYPTO_HASH_ALG_SHA512;
break;
default:
error_setg(errp, "Unsupported rsa hash algo: %d", virtio_hash_alg);
return -1;
}
return 0;
}
if (virtio_padding_alg == VIRTIO_CRYPTO_RSA_RAW_PADDING) {
opt->padding_alg = QCRYPTO_RSA_PADDING_ALG_RAW;
return 0;
}
error_setg(errp, "Unsupported rsa padding algo: %u", virtio_padding_alg);
return -1;
}
static int cryptodev_lkcf_get_unused_session_index(CryptoDevBackendLKCF *lkcf)
{
size_t i;
for (i = 0; i < MAX_SESSIONS; i++) {
if (lkcf->sess[i] == NULL) {
return i;
}
}
return -1;
}
static void cryptodev_lkcf_init(CryptoDevBackend *backend, Error **errp)
{
/* Only support one queue */
int queues = backend->conf.peers.queues, i;
CryptoDevBackendClient *cc;
CryptoDevBackendLKCF *lkcf =
CRYPTODEV_BACKEND_LKCF(backend);
if (queues != 1) {
error_setg(errp,
"Only support one queue in cryptodev-builtin backend");
return;
}
lkcf->eventfd = eventfd(0, 0);
if (lkcf->eventfd < 0) {
error_setg(errp, "Failed to create eventfd: %d", errno);
return;
}
cc = cryptodev_backend_new_client("cryptodev-lkcf", NULL);
cc->info_str = g_strdup_printf("cryptodev-lkcf0");
cc->queue_index = 0;
cc->type = CRYPTODEV_BACKEND_TYPE_LKCF;
backend->conf.peers.ccs[0] = cc;
backend->conf.crypto_services =
1u << VIRTIO_CRYPTO_SERVICE_AKCIPHER;
backend->conf.akcipher_algo = 1u << VIRTIO_CRYPTO_AKCIPHER_RSA;
lkcf->running = true;
QSIMPLEQ_INIT(&lkcf->requests);
QSIMPLEQ_INIT(&lkcf->responses);
qemu_mutex_init(&lkcf->mutex);
qemu_mutex_init(&lkcf->rsp_mutex);
qemu_cond_init(&lkcf->cond);
for (i = 0; i < NR_WORKER_THREAD; i++) {
qemu_thread_create(&lkcf->worker_threads[i], "lkcf-worker",
cryptodev_lkcf_worker, lkcf, 0);
}
qemu_set_fd_handler(
lkcf->eventfd, cryptodev_lkcf_handle_response, NULL, lkcf);
cryptodev_backend_set_ready(backend, true);
}
static void cryptodev_lkcf_cleanup(CryptoDevBackend *backend, Error **errp)
{
CryptoDevBackendLKCF *lkcf = CRYPTODEV_BACKEND_LKCF(backend);
size_t i;
int queues = backend->conf.peers.queues;
CryptoDevBackendClient *cc;
CryptoDevLKCFTask *task, *next;
qemu_mutex_lock(&lkcf->mutex);
lkcf->running = false;
qemu_mutex_unlock(&lkcf->mutex);
qemu_cond_broadcast(&lkcf->cond);
close(lkcf->eventfd);
for (i = 0; i < NR_WORKER_THREAD; i++) {
qemu_thread_join(&lkcf->worker_threads[i]);
}
QSIMPLEQ_FOREACH_SAFE(task, &lkcf->requests, queue, next) {
if (task->cb) {
task->cb(task->opaque, task->status);
}
g_free(task);
}
QSIMPLEQ_FOREACH_SAFE(task, &lkcf->responses, queue, next) {
if (task->cb) {
task->cb(task->opaque, task->status);
}
g_free(task);
}
qemu_mutex_destroy(&lkcf->mutex);
qemu_cond_destroy(&lkcf->cond);
qemu_mutex_destroy(&lkcf->rsp_mutex);
for (i = 0; i < MAX_SESSIONS; i++) {
if (lkcf->sess[i] != NULL) {
cryptodev_lkcf_close_session(backend, i, 0, NULL, NULL);
}
}
for (i = 0; i < queues; i++) {
cc = backend->conf.peers.ccs[i];
if (cc) {
cryptodev_backend_free_client(cc);
backend->conf.peers.ccs[i] = NULL;
}
}
cryptodev_backend_set_ready(backend, false);
}
static void cryptodev_lkcf_execute_task(CryptoDevLKCFTask *task)
{
CryptoDevBackendLKCFSession *session = task->sess;
CryptoDevBackendAsymOpInfo *asym_op_info;
bool kick = false;
int ret, status, op_code = task->op_info->op_code;
size_t p8info_len;
g_autofree uint8_t *p8info = NULL;
Error *local_error = NULL;
key_serial_t key_id = INVALID_KEY_ID;
char op_desc[64];
g_autoptr(QCryptoAkCipher) akcipher = NULL;
/**
* We only offload private key session:
* 1. currently, the Linux kernel can only accept public key wrapped
* with X.509 certificates, but unfortunately the cost of making a
* ceritificate with public key is too expensive.
* 2. generally, public key related compution is fast, just compute it with
* thread-pool.
*/
if (session->keytype == QCRYPTO_AKCIPHER_KEY_TYPE_PRIVATE) {
if (qcrypto_akcipher_export_p8info(&session->akcipher_opts,
session->key, session->keylen,
&p8info, &p8info_len,
&local_error) != 0 ||
cryptodev_lkcf_set_op_desc(&session->akcipher_opts, op_desc,
sizeof(op_desc), &local_error) != 0) {
error_report_err(local_error);
} else {
key_id = add_key(KCTL_KEY_TYPE_PKEY, "lkcf-backend-priv-key",
p8info, p8info_len, KCTL_KEY_RING);
}
}
if (key_id < 0) {
if (!qcrypto_akcipher_supports(&session->akcipher_opts)) {
status = -VIRTIO_CRYPTO_NOTSUPP;
goto out;
}
akcipher = qcrypto_akcipher_new(&session->akcipher_opts,
session->keytype,
session->key, session->keylen,
&local_error);
if (!akcipher) {
status = -VIRTIO_CRYPTO_ERR;
goto out;
}
}
asym_op_info = task->op_info->u.asym_op_info;
switch (op_code) {
case VIRTIO_CRYPTO_AKCIPHER_ENCRYPT:
if (key_id >= 0) {
ret = keyctl_pkey_encrypt(key_id, op_desc,
asym_op_info->src, asym_op_info->src_len,
asym_op_info->dst, asym_op_info->dst_len);
} else {
ret = qcrypto_akcipher_encrypt(akcipher,
asym_op_info->src, asym_op_info->src_len,
asym_op_info->dst, asym_op_info->dst_len, &local_error);
}
break;
case VIRTIO_CRYPTO_AKCIPHER_DECRYPT:
if (key_id >= 0) {
ret = keyctl_pkey_decrypt(key_id, op_desc,
asym_op_info->src, asym_op_info->src_len,
asym_op_info->dst, asym_op_info->dst_len);
} else {
ret = qcrypto_akcipher_decrypt(akcipher,
asym_op_info->src, asym_op_info->src_len,
asym_op_info->dst, asym_op_info->dst_len, &local_error);
}
break;
case VIRTIO_CRYPTO_AKCIPHER_SIGN:
if (key_id >= 0) {
ret = keyctl_pkey_sign(key_id, op_desc,
asym_op_info->src, asym_op_info->src_len,
asym_op_info->dst, asym_op_info->dst_len);
} else {
ret = qcrypto_akcipher_sign(akcipher,
asym_op_info->src, asym_op_info->src_len,
asym_op_info->dst, asym_op_info->dst_len, &local_error);
}
break;
case VIRTIO_CRYPTO_AKCIPHER_VERIFY:
if (key_id >= 0) {
ret = keyctl_pkey_verify(key_id, op_desc,
asym_op_info->src, asym_op_info->src_len,
asym_op_info->dst, asym_op_info->dst_len);
} else {
ret = qcrypto_akcipher_verify(akcipher,
asym_op_info->src, asym_op_info->src_len,
asym_op_info->dst, asym_op_info->dst_len, &local_error);
}
break;
default:
error_setg(&local_error, "Unknown opcode: %u", op_code);
status = -VIRTIO_CRYPTO_ERR;
goto out;
}
if (ret < 0) {
if (!local_error) {
if (errno != EKEYREJECTED) {
error_report("Failed do operation with keyctl: %d", errno);
}
} else {
error_report_err(local_error);
}
status = op_code == VIRTIO_CRYPTO_AKCIPHER_VERIFY ?
-VIRTIO_CRYPTO_KEY_REJECTED : -VIRTIO_CRYPTO_ERR;
} else {
status = VIRTIO_CRYPTO_OK;
asym_op_info->dst_len = ret;
}
out:
if (key_id >= 0) {
keyctl_unlink(key_id, KCTL_KEY_RING);
}
task->status = status;
qemu_mutex_lock(&task->lkcf->rsp_mutex);
if (QSIMPLEQ_EMPTY(&task->lkcf->responses)) {
kick = true;
}
QSIMPLEQ_INSERT_TAIL(&task->lkcf->responses, task, queue);
qemu_mutex_unlock(&task->lkcf->rsp_mutex);
if (kick) {
eventfd_write(task->lkcf->eventfd, 1);
}
}
static void *cryptodev_lkcf_worker(void *arg)
{
CryptoDevBackendLKCF *backend = (CryptoDevBackendLKCF *)arg;
CryptoDevLKCFTask *task;
for (;;) {
task = NULL;
qemu_mutex_lock(&backend->mutex);
while (backend->running && QSIMPLEQ_EMPTY(&backend->requests)) {
qemu_cond_wait(&backend->cond, &backend->mutex);
}
if (backend->running) {
task = QSIMPLEQ_FIRST(&backend->requests);
QSIMPLEQ_REMOVE_HEAD(&backend->requests, queue);
}
qemu_mutex_unlock(&backend->mutex);
/* stopped */
if (!task) {
break;
}
cryptodev_lkcf_execute_task(task);
}
return NULL;
}
static int cryptodev_lkcf_operation(
CryptoDevBackend *backend,
CryptoDevBackendOpInfo *op_info,
uint32_t queue_index,
CryptoDevCompletionFunc cb,
void *opaque)
{
CryptoDevBackendLKCF *lkcf =
CRYPTODEV_BACKEND_LKCF(backend);
CryptoDevBackendLKCFSession *sess;
enum CryptoDevBackendAlgType algtype = op_info->algtype;
CryptoDevLKCFTask *task;
if (op_info->session_id >= MAX_SESSIONS ||
lkcf->sess[op_info->session_id] == NULL) {
error_report("Cannot find a valid session id: %" PRIu64 "",
op_info->session_id);
return -VIRTIO_CRYPTO_INVSESS;
}
sess = lkcf->sess[op_info->session_id];
if (algtype != CRYPTODEV_BACKEND_ALG_ASYM) {
error_report("algtype not supported: %u", algtype);
return -VIRTIO_CRYPTO_NOTSUPP;
}
task = g_new0(CryptoDevLKCFTask, 1);
task->op_info = op_info;
task->cb = cb;
task->opaque = opaque;
task->sess = sess;
task->lkcf = lkcf;
task->status = -VIRTIO_CRYPTO_ERR;
qemu_mutex_lock(&lkcf->mutex);
QSIMPLEQ_INSERT_TAIL(&lkcf->requests, task, queue);
qemu_mutex_unlock(&lkcf->mutex);
qemu_cond_signal(&lkcf->cond);
return VIRTIO_CRYPTO_OK;
}
static int cryptodev_lkcf_create_asym_session(
CryptoDevBackendLKCF *lkcf,
CryptoDevBackendAsymSessionInfo *sess_info,
uint64_t *session_id)
{
Error *local_error = NULL;
int index;
g_autofree CryptoDevBackendLKCFSession *sess =
g_new0(CryptoDevBackendLKCFSession, 1);
switch (sess_info->algo) {
case VIRTIO_CRYPTO_AKCIPHER_RSA:
sess->akcipher_opts.alg = QCRYPTO_AKCIPHER_ALG_RSA;
if (cryptodev_lkcf_set_rsa_opt(
sess_info->u.rsa.padding_algo, sess_info->u.rsa.hash_algo,
&sess->akcipher_opts.u.rsa, &local_error) != 0) {
error_report_err(local_error);
return -VIRTIO_CRYPTO_ERR;
}
break;
default:
error_report("Unsupported asym alg %u", sess_info->algo);
return -VIRTIO_CRYPTO_NOTSUPP;
}
switch (sess_info->keytype) {
case VIRTIO_CRYPTO_AKCIPHER_KEY_TYPE_PUBLIC:
sess->keytype = QCRYPTO_AKCIPHER_KEY_TYPE_PUBLIC;
break;
case VIRTIO_CRYPTO_AKCIPHER_KEY_TYPE_PRIVATE:
sess->keytype = QCRYPTO_AKCIPHER_KEY_TYPE_PRIVATE;
break;
default:
error_report("Unknown akcipher keytype: %u", sess_info->keytype);
return -VIRTIO_CRYPTO_ERR;
}
index = cryptodev_lkcf_get_unused_session_index(lkcf);
if (index < 0) {
error_report("Total number of sessions created exceeds %u",
MAX_SESSIONS);
return -VIRTIO_CRYPTO_ERR;
}
sess->keylen = sess_info->keylen;
sess->key = g_malloc(sess_info->keylen);
memcpy(sess->key, sess_info->key, sess_info->keylen);
lkcf->sess[index] = g_steal_pointer(&sess);
*session_id = index;
return VIRTIO_CRYPTO_OK;
}
static int cryptodev_lkcf_create_session(
CryptoDevBackend *backend,
CryptoDevBackendSessionInfo *sess_info,
uint32_t queue_index,
CryptoDevCompletionFunc cb,
void *opaque)
{
CryptoDevBackendAsymSessionInfo *asym_sess_info;
CryptoDevBackendLKCF *lkcf =
CRYPTODEV_BACKEND_LKCF(backend);
int ret;
switch (sess_info->op_code) {
case VIRTIO_CRYPTO_AKCIPHER_CREATE_SESSION:
asym_sess_info = &sess_info->u.asym_sess_info;
ret = cryptodev_lkcf_create_asym_session(
lkcf, asym_sess_info, &sess_info->session_id);
break;
default:
ret = -VIRTIO_CRYPTO_NOTSUPP;
error_report("Unsupported opcode: %" PRIu32 "",
sess_info->op_code);
break;
}
if (cb) {
cb(opaque, ret);
}
return 0;
}
static int cryptodev_lkcf_close_session(CryptoDevBackend *backend,
uint64_t session_id,
uint32_t queue_index,
CryptoDevCompletionFunc cb,
void *opaque)
{
CryptoDevBackendLKCF *lkcf = CRYPTODEV_BACKEND_LKCF(backend);
CryptoDevBackendLKCFSession *session;
assert(session_id < MAX_SESSIONS && lkcf->sess[session_id]);
session = lkcf->sess[session_id];
lkcf->sess[session_id] = NULL;
g_free(session->key);
g_free(session);
if (cb) {
cb(opaque, VIRTIO_CRYPTO_OK);
}
return 0;
}
static void cryptodev_lkcf_class_init(ObjectClass *oc, void *data)
{
CryptoDevBackendClass *bc = CRYPTODEV_BACKEND_CLASS(oc);
bc->init = cryptodev_lkcf_init;
bc->cleanup = cryptodev_lkcf_cleanup;
bc->create_session = cryptodev_lkcf_create_session;
bc->close_session = cryptodev_lkcf_close_session;
bc->do_op = cryptodev_lkcf_operation;
}
static const TypeInfo cryptodev_builtin_info = {
.name = TYPE_CRYPTODEV_BACKEND_LKCF,
.parent = TYPE_CRYPTODEV_BACKEND,
.class_init = cryptodev_lkcf_class_init,
.instance_size = sizeof(CryptoDevBackendLKCF),
};
static void cryptodev_lkcf_register_types(void)
{
type_register_static(&cryptodev_builtin_info);
}
type_init(cryptodev_lkcf_register_types);