54e7aac056
Add the ability for the secret object to obtain secret data from the Linux in-kernel key managment and retention facility, as an extra option to the existing ones: reading from a file or passing directly as a string. The secret is identified by the key serial number. The upper layers need to instantiate the key and make sure the QEMU process has access permissions to read it. Signed-off-by: Alexey Krasikov <alex-krasikov@yandex-team.ru> - Fixed up detection logic default behaviour in configure Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
149 lines
3.9 KiB
C
149 lines
3.9 KiB
C
/*
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* QEMU crypto secret support
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*
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* Copyright 2020 Yandex N.V.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include "qemu/osdep.h"
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#include <asm/unistd.h>
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#include <linux/keyctl.h>
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#include "qapi/error.h"
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#include "qom/object_interfaces.h"
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#include "trace.h"
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#include "crypto/secret_keyring.h"
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static inline
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long keyctl_read(int32_t key, uint8_t *buffer, size_t buflen)
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{
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return syscall(__NR_keyctl, KEYCTL_READ, key, buffer, buflen, 0);
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}
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static void
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qcrypto_secret_keyring_load_data(QCryptoSecretCommon *sec_common,
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uint8_t **output,
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size_t *outputlen,
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Error **errp)
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{
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QCryptoSecretKeyring *secret = QCRYPTO_SECRET_KEYRING(sec_common);
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uint8_t *buffer = NULL;
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long retcode;
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*output = NULL;
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*outputlen = 0;
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if (!secret->serial) {
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error_setg(errp, "'serial' parameter must be provided");
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return;
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}
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retcode = keyctl_read(secret->serial, NULL, 0);
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if (retcode <= 0) {
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goto keyctl_error;
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}
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buffer = g_new0(uint8_t, retcode);
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retcode = keyctl_read(secret->serial, buffer, retcode);
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if (retcode < 0) {
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g_free(buffer);
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goto keyctl_error;
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}
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*outputlen = retcode;
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*output = buffer;
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return;
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keyctl_error:
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error_setg_errno(errp, errno,
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"Unable to read serial key %08x",
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secret->serial);
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}
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static void
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qcrypto_secret_prop_set_key(Object *obj, Visitor *v,
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const char *name, void *opaque,
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Error **errp)
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{
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QCryptoSecretKeyring *secret = QCRYPTO_SECRET_KEYRING(obj);
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int32_t value;
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visit_type_int32(v, name, &value, errp);
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if (!value) {
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error_setg(errp, "'serial' should not be equal to 0");
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}
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secret->serial = value;
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}
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static void
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qcrypto_secret_prop_get_key(Object *obj, Visitor *v,
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const char *name, void *opaque,
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Error **errp)
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{
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QCryptoSecretKeyring *secret = QCRYPTO_SECRET_KEYRING(obj);
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int32_t value = secret->serial;
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visit_type_int32(v, name, &value, errp);
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}
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static void
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qcrypto_secret_keyring_complete(UserCreatable *uc, Error **errp)
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{
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object_property_set_bool(OBJECT(uc), true, "loaded", errp);
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}
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static void
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qcrypto_secret_keyring_class_init(ObjectClass *oc, void *data)
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{
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QCryptoSecretCommonClass *sic = QCRYPTO_SECRET_COMMON_CLASS(oc);
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sic->load_data = qcrypto_secret_keyring_load_data;
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UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
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ucc->complete = qcrypto_secret_keyring_complete;
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object_class_property_add(oc, "serial", "int32_t",
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qcrypto_secret_prop_get_key,
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qcrypto_secret_prop_set_key,
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NULL, NULL);
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}
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static const TypeInfo qcrypto_secret_info = {
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.parent = TYPE_QCRYPTO_SECRET_COMMON,
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.name = TYPE_QCRYPTO_SECRET_KEYRING,
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.instance_size = sizeof(QCryptoSecretKeyring),
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.class_size = sizeof(QCryptoSecretKeyringClass),
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.class_init = qcrypto_secret_keyring_class_init,
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.interfaces = (InterfaceInfo[]) {
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{ TYPE_USER_CREATABLE },
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{ }
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}
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};
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static void
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qcrypto_secret_register_types(void)
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{
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type_register_static(&qcrypto_secret_info);
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}
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type_init(qcrypto_secret_register_types);
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