[2/2] qga: add ssh-{add,remove}-authorized-keys

Message ID	20201013202502.335336-3-marcandre.lureau@redhat.com
State	New
Headers	show Return-Path: <qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org> From: marcandre.lureau@redhat.com To: qemu-devel@nongnu.org Subject: [PATCH 2/2] qga: add ssh-{add,remove}-authorized-keys Date: Wed, 14 Oct 2020 00:25:02 +0400 Message-Id: <20201013202502.335336-3-marcandre.lureau@redhat.com> In-Reply-To: <20201013202502.335336-1-marcandre.lureau@redhat.com> References: <20201013202502.335336-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=marcandre.lureau@redhat.com; helo=us-smtp-delivery-124.mimecast.com Precedence: list Cc: =?utf-8?q?Marc-Andr=C3=A9_Lureau?= <marcandre.lureau@redhat.com>, berrange@redhat.com, Michael Roth <mdroth@linux.vnet.ibm.com> Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" <qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>
Series	qemu-ga: add ssh-{add,remove}-authorized-keys \| expand [0/2] qemu-ga: add ssh-{add,remove}-authorized-keys [1/2] glib-compat: add g_unix_get_passwd_entry_qemu() [2/2] qga: add ssh-{add,remove}-authorized-keys

diff --git a/qga/commands-posix-ssh.c b/qga/commands-posix-ssh.c new file mode 100644 index 0000000000..3721ac4975 --- /dev/null +++ b/qga/commands-posix-ssh.c @@ -0,0 +1,394 @@ + /* + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ +#include "qemu/osdep.h" + +#include <glib-unix.h> +#include <glib/gstdio.h> +#include <locale.h> +#include <pwd.h> + +#include "qapi/error.h" +#include "qga-qapi-commands.h" + +#ifdef QGA_BUILD_UNIT_TEST +static struct passwd * +test_get_passwd_entry(const gchar *user_name, GError **error) +{ + struct passwd *p; + int ret; + + if (!user_name || g_strcmp0(user_name, g_get_user_name())) { + g_set_error_literal(error, G_FILE_ERROR, G_FILE_ERROR_FAILED, "Invalid user name"); + return NULL; + } + + p = g_new0(struct passwd, 1); + p->pw_dir = (char *)g_get_home_dir(); + p->pw_uid = geteuid(); + p->pw_gid = getegid(); + + ret = g_mkdir_with_parents(p->pw_dir, 0700); + g_assert_cmpint(ret, ==, 0); + + return p; +} + +#define g_unix_get_passwd_entry_qemu(username, err) test_get_passwd_entry(username, err) +#endif + +static struct passwd * +get_passwd_entry(const char *username, Error **errp) +{ + g_autoptr(GError) err = NULL; + struct passwd *p; + + ERRP_GUARD(); + + p = g_unix_get_passwd_entry_qemu(username, &err); + if (p == NULL) { + error_setg(errp, "failed to lookup user '%s': %s", + username, err->message); + return NULL; + } + + return p; +} + +static bool +mkdir_for_user(const char *path, const struct passwd *p, mode_t mode, Error **errp) +{ + ERRP_GUARD(); + + if (g_mkdir(path, mode) == -1) { + error_setg(errp, "failed to create directory '%s': %s", + path, g_strerror(errno)); + return false; + } + + if (chown(path, p->pw_uid, p->pw_gid) == -1) { + error_setg(errp, "failed to set ownership of directory '%s': %s", + path, g_strerror(errno)); + return false; + } + + if (chmod(path, mode) == -1) { + error_setg(errp, "failed to set permissions of directory '%s': %s", + path, g_strerror(errno)); + return false; + } + + return true; +} + +static bool +check_openssh_pub_key(const char *key, Error **errp) +{ + ERRP_GUARD(); + + /* simple sanity-check, we may want more? */ + if (!key || key[0] == '#' || strchr(key, '\n')) { + error_setg(errp, "invalid OpenSSH public key: '%s'", key); + return false; + } + + return true; +} + +static bool +check_openssh_pub_keys(strList *keys, size_t *nkeys, Error **errp) +{ + size_t n = 0; + strList *k; + + ERRP_GUARD(); + + for (k = keys; k != NULL; k = k->next) { + if (!check_openssh_pub_key(k->value, errp)) { + return false; + } + n++; + } + + if (nkeys) { + *nkeys = n; + } + return true; +} + +static bool +write_authkeys(const char *path, const GStrv keys, Error **errp) +{ + g_autofree char *contents = NULL; + g_autoptr(GError) err = NULL; + + ERRP_GUARD(); + + contents = g_strjoinv("\n", keys); + if (!g_file_set_contents(path, contents, -1, &err)) { + error_setg(errp, "failed to write to '%s': %s", path, err->message); + return false; + } + + if (chmod(path, 0600) == -1) { + error_setg(errp, "failed to set permissions of '%s': %s", + path, g_strerror(errno)); + return false; + } + + return true; +} + +static GStrv +read_authkeys(const char *path, Error **errp) +{ + g_autoptr(GError) err = NULL; + g_autofree char *contents = NULL; + + ERRP_GUARD(); + + if (!g_file_get_contents(path, &contents, NULL, &err)) { + error_setg(errp, "failed to read '%s': %s", path, err->message); + return NULL; + } + + return g_strsplit(contents, "\n", -1); + +} + +void +qmp_guest_ssh_add_authorized_keys(const char *username, strList *keys, + Error **errp) +{ + g_autofree struct passwd *p = NULL; + g_autofree char *ssh_path = NULL; + g_autofree char *authkeys_path = NULL; + g_auto(GStrv) authkeys = NULL; + strList *k; + size_t nkeys, nauthkeys; + + ERRP_GUARD(); + + if (!check_openssh_pub_keys(keys, &nkeys, errp)) { + return; + } + + p = get_passwd_entry(username, errp); + if (p == NULL) { + return; + } + + ssh_path = g_build_filename(p->pw_dir, ".ssh", NULL); + authkeys_path = g_build_filename(ssh_path, "authorized_keys", NULL); + + authkeys = read_authkeys(authkeys_path, NULL); + if (authkeys == NULL) { + if (!g_file_test(ssh_path, G_FILE_TEST_IS_DIR) && + !mkdir_for_user(ssh_path, p, 0700, errp)) { + return; + } + } + + nauthkeys = authkeys ? g_strv_length(authkeys) : 0; + authkeys = g_realloc_n(authkeys, nauthkeys + nkeys + 1, sizeof(char *)); + memset(authkeys + nauthkeys, 0, (nkeys + 1) * sizeof(char *)); + + for (k = keys; k != NULL; k = k->next) { + if (g_strv_contains((const gchar * const *)authkeys, k->value)) { + continue; + } + authkeys[nauthkeys++] = g_strdup(k->value); + } + + write_authkeys(authkeys_path, authkeys, errp); +} + +void +qmp_guest_ssh_remove_authorized_keys(const char *username, strList *keys, + Error **errp) +{ + g_autofree struct passwd *p = NULL; + g_autofree char *authkeys_path = NULL; + g_autofree GStrv new_keys = NULL; /* do not own the strings */ + g_auto(GStrv) authkeys = NULL; + GStrv a; + size_t nkeys = 0; + + ERRP_GUARD(); + + if (!check_openssh_pub_keys(keys, NULL, errp)) { + return; + } + + p = get_passwd_entry(username, errp); + if (p == NULL) { + return; + } + + authkeys_path = g_build_filename(p->pw_dir, ".ssh", + "authorized_keys", NULL); + if (!g_file_test(authkeys_path, G_FILE_TEST_EXISTS)) { + return; + } + authkeys = read_authkeys(authkeys_path, errp); + if (authkeys == NULL) { + return; + } + + new_keys = g_new0(char *, g_strv_length(authkeys) + 1); + for (a = authkeys; *a != NULL; a++) { + strList *k; + + for (k = keys; k != NULL; k = k->next) { + if (g_str_equal(k->value, *a)) { + break; + } + } + if (k != NULL) { + continue; + } + + new_keys[nkeys++] = *a; + } + + write_authkeys(authkeys_path, new_keys, errp); +} + + +#ifdef QGA_BUILD_UNIT_TEST +static const strList test_key2 = { + .value = (char *)"algo key2 comments" +}; + +static const strList test_key1_2 = { + .value = (char *)"algo key1 comments", + .next = (strList *)&test_key2, +}; + +static char * +test_get_authorized_keys_path(void) +{ + return g_build_filename(g_get_home_dir(), ".ssh", "authorized_keys", NULL); +} + +static void +test_authorized_keys_set(const char *contents) +{ + g_autoptr(GError) err = NULL; + g_autofree char *path = NULL; + int ret; + + path = g_build_filename(g_get_home_dir(), ".ssh", NULL); + ret = g_mkdir_with_parents(path, 0700); + g_assert_cmpint(ret, ==, 0); + g_free(path); + + path = test_get_authorized_keys_path(); + g_file_set_contents(path, contents, -1, &err); + g_assert_no_error(err); +} + +static void +test_authorized_keys_equal(const char *expected) +{ + g_autoptr(GError) err = NULL; + g_autofree char *path = NULL; + g_autofree char *contents = NULL; + + path = test_get_authorized_keys_path(); + g_file_get_contents(path, &contents, NULL, &err); + g_assert_no_error(err); + + g_assert_cmpstr(contents, ==, expected); +} + +static void +test_invalid_user(void) +{ + Error *err = NULL; + + qmp_guest_ssh_add_authorized_keys("", NULL, &err); + error_free_or_abort(&err); + + qmp_guest_ssh_remove_authorized_keys("", NULL, &err); + error_free_or_abort(&err); +} + +static void +test_invalid_key(void) +{ + strList key = { + .value = (char *)"not a valid\nkey" + }; + Error *err = NULL; + + qmp_guest_ssh_add_authorized_keys(g_get_user_name(), &key, &err); + error_free_or_abort(&err); + + qmp_guest_ssh_remove_authorized_keys(g_get_user_name(), &key, &err); + error_free_or_abort(&err); +} + +static void +test_add_keys(void) +{ + Error *err = NULL; + + qmp_guest_ssh_add_authorized_keys(g_get_user_name(), + (strList *)&test_key2, &err); + g_assert_null(err); + + test_authorized_keys_equal("algo key2 comments"); + + qmp_guest_ssh_add_authorized_keys(g_get_user_name(), + (strList *)&test_key1_2, &err); + g_assert_null(err); + + /* key2 came first, and should'nt be duplicated */ + test_authorized_keys_equal("algo key2 comments\n" + "algo key1 comments"); +} + +static void +test_remove_keys(void) +{ + Error *err = NULL; + static const char *authkeys = + "algo key1 comments\n" + /* originally duplicated */ + "algo key1 comments\n" + "# a commented line\n" + "algo some-key another\n"; + + test_authorized_keys_set(authkeys); + qmp_guest_ssh_remove_authorized_keys(g_get_user_name(), + (strList *)&test_key2, &err); + g_assert_null(err); + test_authorized_keys_equal(authkeys); + + qmp_guest_ssh_remove_authorized_keys(g_get_user_name(), + (strList *)&test_key1_2, &err); + g_assert_null(err); + test_authorized_keys_equal("# a commented line\n" + "algo some-key another\n"); +} + +int main(int argc, char *argv[]) +{ +#if GLIB_CHECK_VERSION(2, 60, 0) + setlocale(LC_ALL, ""); + + g_test_init(&argc, &argv, G_TEST_OPTION_ISOLATE_DIRS, NULL); + + g_test_add_func("/qga/ssh/invalid_user", test_invalid_user); + g_test_add_func("/qga/ssh/invalid_key", test_invalid_key); + g_test_add_func("/qga/ssh/add_keys", test_add_keys); + g_test_add_func("/qga/ssh/remove_keys", test_remove_keys); + + return g_test_run(); +#else + g_test_message("test skipped, needs glib >= 2.60"); +#endif +} +#endif /* BUILD_UNIT_TEST */ diff --git a/qga/commands-win32.c b/qga/commands-win32.c index 0c3c05484f..27ac3f24f5 100644 --- a/qga/commands-win32.c +++ b/qga/commands-win32.c @@ -2457,3 +2457,13 @@ GuestDeviceInfoList *qmp_guest_get_devices(Error **errp) } return head; } + +void qmp_guest_ssh_add_authorized_keys(const char *username, strList *keys, Error **errp) +{ + error_setg(errp, QERR_UNSUPPORTED); +} + +void qmp_guest_ssh_remove_authorized_keys(const char *username, strList *keys, Error **errp) +{ + error_setg(errp, QERR_UNSUPPORTED); +} diff --git a/qga/meson.build b/qga/meson.build index cd08bd953a..58303c70d8 100644 --- a/qga/meson.build +++ b/qga/meson.build @@ -35,7 +35,9 @@ qga_ss.add(files( )) qga_ss.add(when: 'CONFIG_POSIX', if_true: files( 'channel-posix.c', - 'commands-posix.c')) + 'commands-posix.c', + 'commands-posix-ssh.c', +)) qga_ss.add(when: 'CONFIG_WIN32', if_true: files( 'channel-win32.c', 'commands-win32.c', @@ -87,3 +89,16 @@ else endif alias_target('qemu-ga', all_qga) + +qga_ssh_test = executable('qga-ssh-test', + files('commands-posix-ssh.c'), + dependencies: [qemuutil], + c_args: ['-DQGA_BUILD_UNIT_TEST']) + +test_env = environment() +test_env.set('G_TEST_SRCDIR', meson.current_source_dir()) +test_env.set('G_TEST_BUILDDIR', meson.current_build_dir()) +test('qga-ssh-test', + qga_ssh_test, + env: test_env, + suite: ['unit', 'qga']) diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json index cec98c7e06..50e2854b45 100644 --- a/qga/qapi-schema.json +++ b/qga/qapi-schema.json @@ -1306,3 +1306,35 @@ ## { 'command': 'guest-get-devices', 'returns': ['GuestDeviceInfo'] } + +## +# @guest-ssh-add-authorized-keys: +# +# @username: the user account to add the authorized key +# @keys: the public keys to add (in OpenSSH format) +# +# Append a public key to user $HOME/.ssh/authorized_keys on Unix systems (not +# implemented for other systems). +# +# Returns: Nothing on success. +# +# Since: 5.2 +## +{ 'command': 'guest-ssh-add-authorized-keys', + 'data': { 'username': 'str', 'keys': ['str'] } } + +## +# @guest-ssh-remove-authorized-keys: +# +# @username: the user account to add the authorized key +# @keys: the public keys to remove (in OpenSSH format) +# +# Remove public keys from the user $HOME/.ssh/authorized_keys on Unix systems +# (not implemented for other systems). +# +# Returns: Nothing on success. +# +# Since: 5.2 +## +{ 'command': 'guest-ssh-remove-authorized-keys', + 'data': { 'username': 'str', 'keys': ['str'] } }

[2/2] qga: add ssh-{add,remove}-authorized-keys

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