From 54e7aac0562452e4fcab65ca5001d030eef2de15 Mon Sep 17 00:00:00 2001 From: Alexey Krasikov Date: Mon, 25 May 2020 14:19:12 +0300 Subject: [PATCH] crypto/linux_keyring: add 'secret_keyring' secret object. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 - Fixed up detection logic default behaviour in configure Signed-off-by: Daniel P. Berrangé --- configure | 45 ++++++++++ crypto/Makefile.objs | 1 + crypto/secret_keyring.c | 148 ++++++++++++++++++++++++++++++++ include/crypto/secret_keyring.h | 52 +++++++++++ 4 files changed, 246 insertions(+) create mode 100644 crypto/secret_keyring.c create mode 100644 include/crypto/secret_keyring.h diff --git a/configure b/configure index 997284e094..3fbb61905a 100755 --- a/configure +++ b/configure @@ -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 > $TMPC << EOF +#include +#include +#include +#include +int main(void) { + return syscall(__NR_keyctl, KEYCTL_READ, 0, NULL, NULL, 0); +} +EOF + if compile_prog "" "" ; then + have_keyring=yes + fi +fi +if test "$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 diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs index 110dec1b87..707c02ad37 100644 --- a/crypto/Makefile.objs +++ b/crypto/Makefile.objs @@ -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 diff --git a/crypto/secret_keyring.c b/crypto/secret_keyring.c new file mode 100644 index 0000000000..4f132d6370 --- /dev/null +++ b/crypto/secret_keyring.c @@ -0,0 +1,148 @@ +/* + * 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 . + * + */ + +#include "qemu/osdep.h" +#include +#include +#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); diff --git a/include/crypto/secret_keyring.h b/include/crypto/secret_keyring.h new file mode 100644 index 0000000000..9f371ad251 --- /dev/null +++ b/include/crypto/secret_keyring.h @@ -0,0 +1,52 @@ +/* + * 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 . + * + */ + +#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 */