diff options
| -rw-r--r-- | authz/Makefile.objs | 3 | ||||
| -rw-r--r-- | authz/pamacct.c | 148 | ||||
| -rw-r--r-- | authz/trace-events | 3 | ||||
| -rwxr-xr-x | configure | 37 | ||||
| -rw-r--r-- | include/authz/pamacct.h | 100 | ||||
| -rw-r--r-- | qemu-options.hx | 35 | ||||
| -rw-r--r-- | tests/Makefile.include | 2 | ||||
| -rw-r--r-- | tests/test-authz-pam.c | 124 |
8 files changed, 452 insertions, 0 deletions
diff --git a/authz/Makefile.objs b/authz/Makefile.objs index 8351bf181d..ed7b273596 100644 --- a/authz/Makefile.objs +++ b/authz/Makefile.objs @@ -2,3 +2,6 @@ authz-obj-y += base.o authz-obj-y += simple.o authz-obj-y += list.o authz-obj-y += listfile.o +authz-obj-$(CONFIG_AUTH_PAM) += pamacct.o + +pamacct.o-libs = -lpam diff --git a/authz/pamacct.c b/authz/pamacct.c new file mode 100644 index 0000000000..5038358cdc --- /dev/null +++ b/authz/pamacct.c @@ -0,0 +1,148 @@ +/* + * QEMU PAM authorization driver + * + * Copyright (c) 2018 Red Hat, Inc. + * + * 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 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 "authz/pamacct.h" +#include "authz/trace.h" +#include "qom/object_interfaces.h" + +#include <security/pam_appl.h> + + +static bool qauthz_pam_is_allowed(QAuthZ *authz, + const char *identity, + Error **errp) +{ + QAuthZPAM *pauthz = QAUTHZ_PAM(authz); + const struct pam_conv pam_conversation = { 0 }; + pam_handle_t *pamh = NULL; + int ret; + + trace_qauthz_pam_check(authz, identity, pauthz->service); + ret = pam_start(pauthz->service, + identity, + &pam_conversation, + &pamh); + if (ret != PAM_SUCCESS) { + error_setg(errp, "Unable to start PAM transaction: %s", + pam_strerror(NULL, ret)); + return false; + } + + ret = pam_acct_mgmt(pamh, PAM_SILENT); + pam_end(pamh, ret); + if (ret != PAM_SUCCESS) { + error_setg(errp, "Unable to authorize user '%s': %s", + identity, pam_strerror(pamh, ret)); + return false; + } + + return true; +} + + +static void +qauthz_pam_prop_set_service(Object *obj, + const char *service, + Error **errp G_GNUC_UNUSED) +{ + QAuthZPAM *pauthz = QAUTHZ_PAM(obj); + + g_free(pauthz->service); + pauthz->service = g_strdup(service); +} + + +static char * +qauthz_pam_prop_get_service(Object *obj, + Error **errp G_GNUC_UNUSED) +{ + QAuthZPAM *pauthz = QAUTHZ_PAM(obj); + + return g_strdup(pauthz->service); +} + + +static void +qauthz_pam_complete(UserCreatable *uc, Error **errp) +{ +} + + +static void +qauthz_pam_finalize(Object *obj) +{ + QAuthZPAM *pauthz = QAUTHZ_PAM(obj); + + g_free(pauthz->service); +} + + +static void +qauthz_pam_class_init(ObjectClass *oc, void *data) +{ + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); + QAuthZClass *authz = QAUTHZ_CLASS(oc); + + ucc->complete = qauthz_pam_complete; + authz->is_allowed = qauthz_pam_is_allowed; + + object_class_property_add_str(oc, "service", + qauthz_pam_prop_get_service, + qauthz_pam_prop_set_service, + NULL); +} + + +QAuthZPAM *qauthz_pam_new(const char *id, + const char *service, + Error **errp) +{ + return QAUTHZ_PAM( + object_new_with_props(TYPE_QAUTHZ_PAM, + object_get_objects_root(), + id, errp, + "service", service, + NULL)); +} + + +static const TypeInfo qauthz_pam_info = { + .parent = TYPE_QAUTHZ, + .name = TYPE_QAUTHZ_PAM, + .instance_size = sizeof(QAuthZPAM), + .instance_finalize = qauthz_pam_finalize, + .class_size = sizeof(QAuthZPAMClass), + .class_init = qauthz_pam_class_init, + .interfaces = (InterfaceInfo[]) { + { TYPE_USER_CREATABLE }, + { } + } +}; + + +static void +qauthz_pam_register_types(void) +{ + type_register_static(&qauthz_pam_info); +} + + +type_init(qauthz_pam_register_types); diff --git a/authz/trace-events b/authz/trace-events index fb65349a90..72c411927d 100644 --- a/authz/trace-events +++ b/authz/trace-events @@ -13,3 +13,6 @@ qauthz_list_default_policy(void *authz, const char *identity, int policy) "AuthZ # auth/listfile.c qauthz_list_file_load(void *authz, const char *filename) "AuthZ file %p load filename=%s" qauthz_list_file_refresh(void *authz, const char *filename, int success) "AuthZ file %p load filename=%s success=%d" + +# auth/pam.c +qauthz_pam_check(void *authz, const char *identity, const char *service) "AuthZ PAM %p identity=%s service=%s" @@ -463,6 +463,7 @@ gnutls="" nettle="" gcrypt="" gcrypt_hmac="no" +auth_pam="" vte="" virglrenderer="" tpm="yes" @@ -1381,6 +1382,10 @@ for opt do ;; --enable-gcrypt) gcrypt="yes" ;; + --disable-auth-pam) auth_pam="no" + ;; + --enable-auth-pam) auth_pam="yes" + ;; --enable-rdma) rdma="yes" ;; --disable-rdma) rdma="no" @@ -1707,6 +1712,7 @@ disabled with --disable-FEATURE, default is enabled if available: gnutls GNUTLS cryptography support nettle nettle cryptography support gcrypt libgcrypt cryptography support + auth-pam PAM access control sdl SDL UI sdl_image SDL Image support for icons gtk gtk UI @@ -2865,6 +2871,33 @@ fi ########################################## +# PAM probe + +if test "$auth_pam" != "no"; then + cat > $TMPC <<EOF +#include <security/pam_appl.h> +#include <stdio.h> +int main(void) { + const char *service_name = "qemu"; + const char *user = "frank"; + const struct pam_conv *pam_conv = NULL; + pam_handle_t *pamh = NULL; + pam_start(service_name, user, pam_conv, &pamh); + return 0; +} +EOF + if compile_prog "" "-lpam" ; then + auth_pam=yes + else + if test "$auth_pam" = "yes"; then + feature_not_found "PAM" "Install PAM development package" + else + auth_pam=no + fi + fi +fi + +########################################## # getifaddrs (for tests/test-io-channel-socket ) have_ifaddrs_h=yes @@ -6091,6 +6124,7 @@ echo "GNUTLS support $gnutls" echo "libgcrypt $gcrypt" echo "nettle $nettle $(echo_version $nettle $nettle_version)" echo "libtasn1 $tasn1" +echo "PAM $auth_pam" echo "curses support $curses" echo "virgl support $virglrenderer $(echo_version $virglrenderer $virgl_version)" echo "curl support $curl" @@ -6550,6 +6584,9 @@ fi if test "$tasn1" = "yes" ; then echo "CONFIG_TASN1=y" >> $config_host_mak fi +if test "$auth_pam" = "yes" ; then + echo "CONFIG_AUTH_PAM=y" >> $config_host_mak +fi if test "$have_ifaddrs_h" = "yes" ; then echo "HAVE_IFADDRS_H=y" >> $config_host_mak fi diff --git a/include/authz/pamacct.h b/include/authz/pamacct.h new file mode 100644 index 0000000000..6e3046e528 --- /dev/null +++ b/include/authz/pamacct.h @@ -0,0 +1,100 @@ +/* + * QEMU PAM authorization driver + * + * Copyright (c) 2018 Red Hat, Inc. + * + * 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 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 QAUTHZ_PAM_H__ +#define QAUTHZ_PAM_H__ + +#include "authz/base.h" + + +#define TYPE_QAUTHZ_PAM "authz-pam" + +#define QAUTHZ_PAM_CLASS(klass) \ + OBJECT_CLASS_CHECK(QAuthZPAMClass, (klass), \ + TYPE_QAUTHZ_PAM) +#define QAUTHZ_PAM_GET_CLASS(obj) \ + OBJECT_GET_CLASS(QAuthZPAMClass, (obj), \ + TYPE_QAUTHZ_PAM) +#define QAUTHZ_PAM(obj) \ + INTERFACE_CHECK(QAuthZPAM, (obj), \ + TYPE_QAUTHZ_PAM) + +typedef struct QAuthZPAM QAuthZPAM; +typedef struct QAuthZPAMClass QAuthZPAMClass; + + +/** + * QAuthZPAM: + * + * This authorization driver provides a PAM mechanism + * for granting access by matching user names against a + * list of globs. Each match rule has an associated policy + * and a catch all policy applies if no rule matches + * + * To create an instance of this class via QMP: + * + * { + * "execute": "object-add", + * "arguments": { + * "qom-type": "authz-pam", + * "id": "authz0", + * "parameters": { + * "service": "qemu-vnc-tls" + * } + * } + * } + * + * The driver only uses the PAM "account" verification + * subsystem. The above config would require a config + * file /etc/pam.d/qemu-vnc-tls. For a simple file + * lookup it would contain + * + * account requisite pam_listfile.so item=user sense=allow \ + * file=/etc/qemu/vnc.allow + * + * The external file would then contain a list of usernames. + * If x509 cert was being used as the username, a suitable + * entry would match the distinguish name: + * + * CN=laptop.berrange.com,O=Berrange Home,L=London,ST=London,C=GB + * + * On the command line it can be created using + * + * -object authz-pam,id=authz0,service=qemu-vnc-tls + * + */ +struct QAuthZPAM { + QAuthZ parent_obj; + + char *service; +}; + + +struct QAuthZPAMClass { + QAuthZClass parent_class; +}; + + +QAuthZPAM *qauthz_pam_new(const char *id, + const char *service, + Error **errp); + + +#endif /* QAUTHZ_PAM_H__ */ diff --git a/qemu-options.hx b/qemu-options.hx index 217662acb0..1cf9aac1fe 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4435,6 +4435,41 @@ would look like: ... @end example +@item -object authz-pam,id=@var{id},service=@var{string} + +Create an authorization object that will control access to network services. + +The @option{service} parameter provides the name of a PAM service to use +for authorization. It requires that a file @code{/etc/pam.d/@var{service}} +exist to provide the configuration for the @code{account} subsystem. + +An example authorization object to validate a TLS x509 distinguished +name would look like: + +@example + # $QEMU \ + ... + -object authz-pam,id=auth0,service=qemu-vnc + ... +@end example + +There would then be a corresponding config file for PAM at +@code{/etc/pam.d/qemu-vnc} that contains: + +@example +account requisite pam_listfile.so item=user sense=allow \ + file=/etc/qemu/vnc.allow +@end example + +Finally the @code{/etc/qemu/vnc.allow} file would contain +the list of x509 distingished names that are permitted +access + +@example +CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB +@end example + + @end table ETEXI diff --git a/tests/Makefile.include b/tests/Makefile.include index 9b63d4743c..8778e5145b 100644 --- a/tests/Makefile.include +++ b/tests/Makefile.include @@ -119,6 +119,7 @@ check-unit-y += tests/test-util-sockets$(EXESUF) check-unit-y += tests/test-authz-simple$(EXESUF) check-unit-y += tests/test-authz-list$(EXESUF) check-unit-y += tests/test-authz-listfile$(EXESUF) +check-unit-$(CONFIG_AUTH_PAM) += tests/test-authz-pam$(EXESUF) check-unit-y += tests/test-io-task$(EXESUF) check-unit-y += tests/test-io-channel-socket$(EXESUF) check-unit-y += tests/test-io-channel-file$(EXESUF) @@ -669,6 +670,7 @@ tests/test-util-sockets$(EXESUF): tests/test-util-sockets.o \ tests/test-authz-simple$(EXESUF): tests/test-authz-simple.o $(test-authz-obj-y) tests/test-authz-list$(EXESUF): tests/test-authz-list.o $(test-authz-obj-y) tests/test-authz-listfile$(EXESUF): tests/test-authz-listfile.o $(test-authz-obj-y) +tests/test-authz-pam$(EXESUF): tests/test-authz-pam.o $(test-authz-obj-y) tests/test-io-task$(EXESUF): tests/test-io-task.o $(test-io-obj-y) tests/test-io-channel-socket$(EXESUF): tests/test-io-channel-socket.o \ tests/io-channel-helpers.o tests/socket-helpers.o $(test-io-obj-y) diff --git a/tests/test-authz-pam.c b/tests/test-authz-pam.c new file mode 100644 index 0000000000..93d5ac8bbf --- /dev/null +++ b/tests/test-authz-pam.c @@ -0,0 +1,124 @@ +/* + * QEMU PAM authorization object tests + * + * Copyright (c) 2018 Red Hat, Inc. + * + * 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 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 "qapi/error.h" +#include "authz/pamacct.h" + +#include <security/pam_appl.h> + +static bool failauth; + +/* + * These two functions are exported by libpam.so. + * + * By defining them again here, our impls are resolved + * by the linker instead of those in libpam.so + * + * The test suite is thus isolated from the host system + * PAM setup, so we can do predictable test scenarios + */ +int +pam_start(const char *service_name, const char *user, + const struct pam_conv *pam_conversation, + pam_handle_t **pamh) +{ + failauth = true; + if (!g_str_equal(service_name, "qemu-vnc")) { + return PAM_AUTH_ERR; + } + + if (g_str_equal(user, "fred")) { + failauth = false; + } + + return PAM_SUCCESS; +} + + +int +pam_acct_mgmt(pam_handle_t *pamh, int flags) +{ + if (failauth) { + return PAM_AUTH_ERR; + } + + return PAM_SUCCESS; +} + + +static void test_authz_unknown_service(void) +{ + Error *local_err = NULL; + QAuthZPAM *auth = qauthz_pam_new("auth0", + "qemu-does-not-exist", + &error_abort); + + g_assert_nonnull(auth); + + g_assert_false(qauthz_is_allowed(QAUTHZ(auth), "fred", &local_err)); + + error_free_or_abort(&local_err); + object_unparent(OBJECT(auth)); +} + + +static void test_authz_good_user(void) +{ + QAuthZPAM *auth = qauthz_pam_new("auth0", + "qemu-vnc", + &error_abort); + + g_assert_nonnull(auth); + + g_assert_true(qauthz_is_allowed(QAUTHZ(auth), "fred", &error_abort)); + + object_unparent(OBJECT(auth)); +} + + +static void test_authz_bad_user(void) +{ + Error *local_err = NULL; + QAuthZPAM *auth = qauthz_pam_new("auth0", + "qemu-vnc", + &error_abort); + + g_assert_nonnull(auth); + + g_assert_false(qauthz_is_allowed(QAUTHZ(auth), "bob", &local_err)); + + error_free_or_abort(&local_err); + object_unparent(OBJECT(auth)); +} + + +int main(int argc, char **argv) +{ + g_test_init(&argc, &argv, NULL); + + module_call_init(MODULE_INIT_QOM); + + g_test_add_func("/auth/pam/unknown-service", test_authz_unknown_service); + g_test_add_func("/auth/pam/good-user", test_authz_good_user); + g_test_add_func("/auth/pam/bad-user", test_authz_bad_user); + + return g_test_run(); +} |