Commit 54e7aac0 authored by Alexey Krasikov's avatar Alexey Krasikov Committed by Daniel P. Berrangé
Browse files

crypto/linux_keyring: add 'secret_keyring' secret object. 



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: default avatarAlexey Krasikov <alex-krasikov@yandex-team.ru>

 - Fixed up detection logic default behaviour in configure

Signed-off-by: default avatarDaniel P. Berrangé <berrange@redhat.com>
parent 4862bd3c

configure

+45 −0
Original line number Diff line number Diff line
@@ -510,6 +510,7 @@ default_devices="yes" 
plugins="no"

fuzzing="no"

rng_none="no"

secret_keyring=""



supported_cpu="no"

supported_os="no"
@@ -1606,6 +1607,10 @@ for opt do 
  ;;

  --disable-rng-none) rng_none=no

  ;;

  --enable-keyring) secret_keyring="yes"

  ;;

  --disable-keyring) secret_keyring="no"

  ;;

  *)

      echo "ERROR: unknown option $opt"

      echo "Try '$0 --help' for more information"
@@ -6290,6 +6295,41 @@ case "$slirp" in 
    ;;

esac



##########################################

# check for usable __NR_keyctl syscall



if test "$linux" = "yes" ; then



    have_keyring=no

    cat > $TMPC << EOF

#include <errno.h>

#include <asm/unistd.h>

#include <linux/keyctl.h>

#include <unistd.h>

int main(void) {

    return syscall(__NR_keyctl, KEYCTL_READ, 0, NULL, NULL, 0);

}

EOF

    if compile_prog "" "" ; then

        have_keyring=yes

    fi

fi

if test "$secret_keyring" != "no"

then

    if test "$have_keyring" == "yes"

    then

	secret_keyring=yes

    else

	if test "$secret_keyring" = "yes"

	then

	    error_exit "syscall __NR_keyctl requested, \

but not implemented on your system"

	else

	    secret_keyring=no

	fi

    fi

fi





##########################################

# End of CC checks
@@ -6774,6 +6814,7 @@ echo "plugin support $plugins" 
echo "fuzzing support   $fuzzing"

echo "gdb               $gdb_bin"

echo "rng-none          $rng_none"

echo "Linux keyring     $secret_keyring"



if test "$supported_cpu" = "no"; then

    echo
@@ -7659,6 +7700,10 @@ if test -n "$gdb_bin" ; then 
    echo "HAVE_GDB_BIN=$gdb_bin" >> $config_host_mak

fi



if test "$secret_keyring" = "yes" ; then

  echo "CONFIG_SECRET_KEYRING=y" >> $config_host_mak

fi



if test "$tcg_interpreter" = "yes"; then

  QEMU_INCLUDES="-iquote \$(SRC_PATH)/tcg/tci $QEMU_INCLUDES"

elif test "$ARCH" = "sparc64" ; then

crypto/Makefile.objs

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ crypto-obj-y += tlscredsx509.o 
crypto-obj-y += tlssession.o

crypto-obj-y += secret_common.o

crypto-obj-y += secret.o

crypto-obj-$(CONFIG_SECRET_KEYRING) += secret_keyring.o

crypto-obj-y += pbkdf.o

crypto-obj-$(CONFIG_NETTLE) += pbkdf-nettle.o

crypto-obj-$(if $(CONFIG_NETTLE),n,$(CONFIG_GCRYPT)) += pbkdf-gcrypt.o

crypto/secret_keyring.c

0 → 100644
+148 −0
Original line number Diff line number Diff line 
/*

 * QEMU crypto secret support

 *

 * Copyright 2020 Yandex N.V.

 *

 * 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 <asm/unistd.h>

#include <linux/keyctl.h>

#include "qapi/error.h"

#include "qom/object_interfaces.h"

#include "trace.h"

#include "crypto/secret_keyring.h"





static inline

long keyctl_read(int32_t key, uint8_t *buffer, size_t buflen)

{

    return syscall(__NR_keyctl, KEYCTL_READ, key, buffer, buflen, 0);

}





static void

qcrypto_secret_keyring_load_data(QCryptoSecretCommon *sec_common,

                                 uint8_t **output,

                                 size_t *outputlen,

                                 Error **errp)

{

    QCryptoSecretKeyring *secret = QCRYPTO_SECRET_KEYRING(sec_common);

    uint8_t *buffer = NULL;

    long retcode;



    *output = NULL;

    *outputlen = 0;



    if (!secret->serial) {

        error_setg(errp, "'serial' parameter must be provided");

        return;

    }



    retcode = keyctl_read(secret->serial, NULL, 0);

    if (retcode <= 0) {

        goto keyctl_error;

    }



    buffer = g_new0(uint8_t, retcode);



    retcode = keyctl_read(secret->serial, buffer, retcode);

    if (retcode < 0) {

        g_free(buffer);

        goto keyctl_error;

    }



    *outputlen = retcode;

    *output = buffer;

    return;



keyctl_error:

    error_setg_errno(errp, errno,

                     "Unable to read serial key %08x",

                     secret->serial);

}





static void

qcrypto_secret_prop_set_key(Object *obj, Visitor *v,

                            const char *name, void *opaque,

                            Error **errp)

{

    QCryptoSecretKeyring *secret = QCRYPTO_SECRET_KEYRING(obj);

    int32_t value;

    visit_type_int32(v, name, &value, errp);

    if (!value) {

        error_setg(errp, "'serial' should not be equal to 0");

    }

    secret->serial = value;

}





static void

qcrypto_secret_prop_get_key(Object *obj, Visitor *v,

                            const char *name, void *opaque,

                            Error **errp)

{

    QCryptoSecretKeyring *secret = QCRYPTO_SECRET_KEYRING(obj);

    int32_t value = secret->serial;

    visit_type_int32(v, name, &value, errp);

}





static void

qcrypto_secret_keyring_complete(UserCreatable *uc, Error **errp)

{

    object_property_set_bool(OBJECT(uc), true, "loaded", errp);

}





static void

qcrypto_secret_keyring_class_init(ObjectClass *oc, void *data)

{

    QCryptoSecretCommonClass *sic = QCRYPTO_SECRET_COMMON_CLASS(oc);

    sic->load_data = qcrypto_secret_keyring_load_data;



    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);

    ucc->complete = qcrypto_secret_keyring_complete;



    object_class_property_add(oc, "serial", "int32_t",

                                  qcrypto_secret_prop_get_key,

                                  qcrypto_secret_prop_set_key,

                                  NULL, NULL);

}





static const TypeInfo qcrypto_secret_info = {

    .parent = TYPE_QCRYPTO_SECRET_COMMON,

    .name = TYPE_QCRYPTO_SECRET_KEYRING,

    .instance_size = sizeof(QCryptoSecretKeyring),

    .class_size = sizeof(QCryptoSecretKeyringClass),

    .class_init = qcrypto_secret_keyring_class_init,

    .interfaces = (InterfaceInfo[]) {

        { TYPE_USER_CREATABLE },

        { }

    }

};





static void

qcrypto_secret_register_types(void)

{

    type_register_static(&qcrypto_secret_info);

}





type_init(qcrypto_secret_register_types);

include/crypto/secret_keyring.h

0 → 100644
+52 −0
Original line number Diff line number Diff line 
/*

 * QEMU crypto secret support

 *

 * Copyright 2020 Yandex N.V.

 *

 * 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/>.

 *

 */



#ifndef QCRYPTO_SECRET_KEYRING_H

#define QCRYPTO_SECRET_KEYRING_H



#include "qapi/qapi-types-crypto.h"

#include "qom/object.h"

#include "crypto/secret_common.h"



#define TYPE_QCRYPTO_SECRET_KEYRING "secret_keyring"

#define QCRYPTO_SECRET_KEYRING(obj) \

    OBJECT_CHECK(QCryptoSecretKeyring, (obj), \

                 TYPE_QCRYPTO_SECRET_KEYRING)

#define QCRYPTO_SECRET_KEYRING_CLASS(class) \

    OBJECT_CLASS_CHECK(QCryptoSecretKeyringClass, \

                       (class), TYPE_QCRYPTO_SECRET_KEYRING)

#define QCRYPTO_SECRET_KEYRING_GET_CLASS(class) \

    OBJECT_GET_CLASS(QCryptoSecretKeyringClass, \

                     (class), TYPE_QCRYPTO_SECRET_KEYRING)



typedef struct QCryptoSecretKeyring QCryptoSecretKeyring;

typedef struct QCryptoSecretKeyringClass QCryptoSecretKeyringClass;



typedef struct QCryptoSecretKeyring {

    QCryptoSecretCommon parent;

    int32_t serial;

} QCryptoSecretKeyring;





typedef struct QCryptoSecretKeyringClass {

    QCryptoSecretCommonClass parent;

} QCryptoSecretKeyringClass;



#endif /* QCRYPTO_SECRET_KEYRING_H */