Merge remote-tracking branch 'remotes/kraxel/tags/vga-20210723-pull-request' into...
[qemu.git] / qga / commands-posix-ssh.c
1 /*
2 * This work is licensed under the terms of the GNU GPL, version 2 or later.
3 * See the COPYING file in the top-level directory.
4 */
5 #include "qemu/osdep.h"
6
7 #include <glib-unix.h>
8 #include <glib/gstdio.h>
9 #include <locale.h>
10 #include <pwd.h>
11
12 #include "qapi/error.h"
13 #include "qga-qapi-commands.h"
14
15 #ifdef QGA_BUILD_UNIT_TEST
16 static struct passwd *
17 test_get_passwd_entry(const gchar *user_name, GError **error)
18 {
19 struct passwd *p;
20 int ret;
21
22 if (!user_name || g_strcmp0(user_name, g_get_user_name())) {
23 g_set_error(error, G_UNIX_ERROR, 0, "Invalid user name");
24 return NULL;
25 }
26
27 p = g_new0(struct passwd, 1);
28 p->pw_dir = (char *)g_get_home_dir();
29 p->pw_uid = geteuid();
30 p->pw_gid = getegid();
31
32 ret = g_mkdir_with_parents(p->pw_dir, 0700);
33 g_assert(ret == 0);
34
35 return p;
36 }
37
38 #define g_unix_get_passwd_entry_qemu(username, err) \
39 test_get_passwd_entry(username, err)
40 #endif
41
42 static struct passwd *
43 get_passwd_entry(const char *username, Error **errp)
44 {
45 g_autoptr(GError) err = NULL;
46 struct passwd *p;
47
48 ERRP_GUARD();
49
50 p = g_unix_get_passwd_entry_qemu(username, &err);
51 if (p == NULL) {
52 error_setg(errp, "failed to lookup user '%s': %s",
53 username, err->message);
54 return NULL;
55 }
56
57 return p;
58 }
59
60 static bool
61 mkdir_for_user(const char *path, const struct passwd *p,
62 mode_t mode, Error **errp)
63 {
64 ERRP_GUARD();
65
66 if (g_mkdir(path, mode) == -1) {
67 error_setg(errp, "failed to create directory '%s': %s",
68 path, g_strerror(errno));
69 return false;
70 }
71
72 if (chown(path, p->pw_uid, p->pw_gid) == -1) {
73 error_setg(errp, "failed to set ownership of directory '%s': %s",
74 path, g_strerror(errno));
75 return false;
76 }
77
78 if (chmod(path, mode) == -1) {
79 error_setg(errp, "failed to set permissions of directory '%s': %s",
80 path, g_strerror(errno));
81 return false;
82 }
83
84 return true;
85 }
86
87 static bool
88 check_openssh_pub_key(const char *key, Error **errp)
89 {
90 ERRP_GUARD();
91
92 /* simple sanity-check, we may want more? */
93 if (!key || key[0] == '#' || strchr(key, '\n')) {
94 error_setg(errp, "invalid OpenSSH public key: '%s'", key);
95 return false;
96 }
97
98 return true;
99 }
100
101 static bool
102 check_openssh_pub_keys(strList *keys, size_t *nkeys, Error **errp)
103 {
104 size_t n = 0;
105 strList *k;
106
107 ERRP_GUARD();
108
109 for (k = keys; k != NULL; k = k->next) {
110 if (!check_openssh_pub_key(k->value, errp)) {
111 return false;
112 }
113 n++;
114 }
115
116 if (nkeys) {
117 *nkeys = n;
118 }
119 return true;
120 }
121
122 static bool
123 write_authkeys(const char *path, const GStrv keys,
124 const struct passwd *p, Error **errp)
125 {
126 g_autofree char *contents = NULL;
127 g_autoptr(GError) err = NULL;
128
129 ERRP_GUARD();
130
131 contents = g_strjoinv("\n", keys);
132 if (!g_file_set_contents(path, contents, -1, &err)) {
133 error_setg(errp, "failed to write to '%s': %s", path, err->message);
134 return false;
135 }
136
137 if (chown(path, p->pw_uid, p->pw_gid) == -1) {
138 error_setg(errp, "failed to set ownership of directory '%s': %s",
139 path, g_strerror(errno));
140 return false;
141 }
142
143 if (chmod(path, 0600) == -1) {
144 error_setg(errp, "failed to set permissions of '%s': %s",
145 path, g_strerror(errno));
146 return false;
147 }
148
149 return true;
150 }
151
152 static GStrv
153 read_authkeys(const char *path, Error **errp)
154 {
155 g_autoptr(GError) err = NULL;
156 g_autofree char *contents = NULL;
157
158 ERRP_GUARD();
159
160 if (!g_file_get_contents(path, &contents, NULL, &err)) {
161 error_setg(errp, "failed to read '%s': %s", path, err->message);
162 return NULL;
163 }
164
165 return g_strsplit(contents, "\n", -1);
166
167 }
168
169 void
170 qmp_guest_ssh_add_authorized_keys(const char *username, strList *keys,
171 bool has_reset, bool reset,
172 Error **errp)
173 {
174 g_autofree struct passwd *p = NULL;
175 g_autofree char *ssh_path = NULL;
176 g_autofree char *authkeys_path = NULL;
177 g_auto(GStrv) authkeys = NULL;
178 strList *k;
179 size_t nkeys, nauthkeys;
180
181 ERRP_GUARD();
182 reset = has_reset && reset;
183
184 if (!check_openssh_pub_keys(keys, &nkeys, errp)) {
185 return;
186 }
187
188 p = get_passwd_entry(username, errp);
189 if (p == NULL) {
190 return;
191 }
192
193 ssh_path = g_build_filename(p->pw_dir, ".ssh", NULL);
194 authkeys_path = g_build_filename(ssh_path, "authorized_keys", NULL);
195
196 if (!reset) {
197 authkeys = read_authkeys(authkeys_path, NULL);
198 }
199 if (authkeys == NULL) {
200 if (!g_file_test(ssh_path, G_FILE_TEST_IS_DIR) &&
201 !mkdir_for_user(ssh_path, p, 0700, errp)) {
202 return;
203 }
204 }
205
206 nauthkeys = authkeys ? g_strv_length(authkeys) : 0;
207 authkeys = g_realloc_n(authkeys, nauthkeys + nkeys + 1, sizeof(char *));
208 memset(authkeys + nauthkeys, 0, (nkeys + 1) * sizeof(char *));
209
210 for (k = keys; k != NULL; k = k->next) {
211 if (g_strv_contains((const gchar * const *)authkeys, k->value)) {
212 continue;
213 }
214 authkeys[nauthkeys++] = g_strdup(k->value);
215 }
216
217 write_authkeys(authkeys_path, authkeys, p, errp);
218 }
219
220 void
221 qmp_guest_ssh_remove_authorized_keys(const char *username, strList *keys,
222 Error **errp)
223 {
224 g_autofree struct passwd *p = NULL;
225 g_autofree char *authkeys_path = NULL;
226 g_autofree GStrv new_keys = NULL; /* do not own the strings */
227 g_auto(GStrv) authkeys = NULL;
228 GStrv a;
229 size_t nkeys = 0;
230
231 ERRP_GUARD();
232
233 if (!check_openssh_pub_keys(keys, NULL, errp)) {
234 return;
235 }
236
237 p = get_passwd_entry(username, errp);
238 if (p == NULL) {
239 return;
240 }
241
242 authkeys_path = g_build_filename(p->pw_dir, ".ssh",
243 "authorized_keys", NULL);
244 if (!g_file_test(authkeys_path, G_FILE_TEST_EXISTS)) {
245 return;
246 }
247 authkeys = read_authkeys(authkeys_path, errp);
248 if (authkeys == NULL) {
249 return;
250 }
251
252 new_keys = g_new0(char *, g_strv_length(authkeys) + 1);
253 for (a = authkeys; *a != NULL; a++) {
254 strList *k;
255
256 for (k = keys; k != NULL; k = k->next) {
257 if (g_str_equal(k->value, *a)) {
258 break;
259 }
260 }
261 if (k != NULL) {
262 continue;
263 }
264
265 new_keys[nkeys++] = *a;
266 }
267
268 write_authkeys(authkeys_path, new_keys, p, errp);
269 }
270
271 GuestAuthorizedKeys *
272 qmp_guest_ssh_get_authorized_keys(const char *username, Error **errp)
273 {
274 g_autofree struct passwd *p = NULL;
275 g_autofree char *authkeys_path = NULL;
276 g_auto(GStrv) authkeys = NULL;
277 g_autoptr(GuestAuthorizedKeys) ret = NULL;
278 int i;
279
280 ERRP_GUARD();
281
282 p = get_passwd_entry(username, errp);
283 if (p == NULL) {
284 return NULL;
285 }
286
287 authkeys_path = g_build_filename(p->pw_dir, ".ssh",
288 "authorized_keys", NULL);
289 authkeys = read_authkeys(authkeys_path, errp);
290 if (authkeys == NULL) {
291 return NULL;
292 }
293
294 ret = g_new0(GuestAuthorizedKeys, 1);
295 for (i = 0; authkeys[i] != NULL; i++) {
296 g_strstrip(authkeys[i]);
297 if (!authkeys[i][0] || authkeys[i][0] == '#') {
298 continue;
299 }
300
301 QAPI_LIST_PREPEND(ret->keys, g_strdup(authkeys[i]));
302 }
303
304 return g_steal_pointer(&ret);
305 }
306
307 #ifdef QGA_BUILD_UNIT_TEST
308 #if GLIB_CHECK_VERSION(2, 60, 0)
309 static const strList test_key2 = {
310 .value = (char *)"algo key2 comments"
311 };
312
313 static const strList test_key1_2 = {
314 .value = (char *)"algo key1 comments",
315 .next = (strList *)&test_key2,
316 };
317
318 static char *
319 test_get_authorized_keys_path(void)
320 {
321 return g_build_filename(g_get_home_dir(), ".ssh", "authorized_keys", NULL);
322 }
323
324 static void
325 test_authorized_keys_set(const char *contents)
326 {
327 g_autoptr(GError) err = NULL;
328 g_autofree char *path = NULL;
329 int ret;
330
331 path = g_build_filename(g_get_home_dir(), ".ssh", NULL);
332 ret = g_mkdir_with_parents(path, 0700);
333 g_assert(ret == 0);
334 g_free(path);
335
336 path = test_get_authorized_keys_path();
337 g_file_set_contents(path, contents, -1, &err);
338 g_assert(err == NULL);
339 }
340
341 static void
342 test_authorized_keys_equal(const char *expected)
343 {
344 g_autoptr(GError) err = NULL;
345 g_autofree char *path = NULL;
346 g_autofree char *contents = NULL;
347
348 path = test_get_authorized_keys_path();
349 g_file_get_contents(path, &contents, NULL, &err);
350 g_assert(err == NULL);
351
352 g_assert(g_strcmp0(contents, expected) == 0);
353 }
354
355 static void
356 test_invalid_user(void)
357 {
358 Error *err = NULL;
359
360 qmp_guest_ssh_add_authorized_keys("", NULL, FALSE, FALSE, &err);
361 error_free_or_abort(&err);
362
363 qmp_guest_ssh_remove_authorized_keys("", NULL, &err);
364 error_free_or_abort(&err);
365 }
366
367 static void
368 test_invalid_key(void)
369 {
370 strList key = {
371 .value = (char *)"not a valid\nkey"
372 };
373 Error *err = NULL;
374
375 qmp_guest_ssh_add_authorized_keys(g_get_user_name(), &key,
376 FALSE, FALSE, &err);
377 error_free_or_abort(&err);
378
379 qmp_guest_ssh_remove_authorized_keys(g_get_user_name(), &key, &err);
380 error_free_or_abort(&err);
381 }
382
383 static void
384 test_add_keys(void)
385 {
386 Error *err = NULL;
387
388 qmp_guest_ssh_add_authorized_keys(g_get_user_name(),
389 (strList *)&test_key2,
390 FALSE, FALSE,
391 &err);
392 g_assert(err == NULL);
393
394 test_authorized_keys_equal("algo key2 comments");
395
396 qmp_guest_ssh_add_authorized_keys(g_get_user_name(),
397 (strList *)&test_key1_2,
398 FALSE, FALSE,
399 &err);
400 g_assert(err == NULL);
401
402 /* key2 came first, and should'nt be duplicated */
403 test_authorized_keys_equal("algo key2 comments\n"
404 "algo key1 comments");
405 }
406
407 static void
408 test_add_reset_keys(void)
409 {
410 Error *err = NULL;
411
412 qmp_guest_ssh_add_authorized_keys(g_get_user_name(),
413 (strList *)&test_key1_2,
414 FALSE, FALSE,
415 &err);
416 g_assert(err == NULL);
417
418 /* reset with key2 only */
419 test_authorized_keys_equal("algo key1 comments\n"
420 "algo key2 comments");
421
422 qmp_guest_ssh_add_authorized_keys(g_get_user_name(),
423 (strList *)&test_key2,
424 TRUE, TRUE,
425 &err);
426 g_assert(err == NULL);
427
428 test_authorized_keys_equal("algo key2 comments");
429
430 /* empty should clear file */
431 qmp_guest_ssh_add_authorized_keys(g_get_user_name(),
432 (strList *)NULL,
433 TRUE, TRUE,
434 &err);
435 g_assert(err == NULL);
436
437 test_authorized_keys_equal("");
438 }
439
440 static void
441 test_remove_keys(void)
442 {
443 Error *err = NULL;
444 static const char *authkeys =
445 "algo key1 comments\n"
446 /* originally duplicated */
447 "algo key1 comments\n"
448 "# a commented line\n"
449 "algo some-key another\n";
450
451 test_authorized_keys_set(authkeys);
452 qmp_guest_ssh_remove_authorized_keys(g_get_user_name(),
453 (strList *)&test_key2, &err);
454 g_assert(err == NULL);
455 test_authorized_keys_equal(authkeys);
456
457 qmp_guest_ssh_remove_authorized_keys(g_get_user_name(),
458 (strList *)&test_key1_2, &err);
459 g_assert(err == NULL);
460 test_authorized_keys_equal("# a commented line\n"
461 "algo some-key another\n");
462 }
463
464 static void
465 test_get_keys(void)
466 {
467 Error *err = NULL;
468 static const char *authkeys =
469 "algo key1 comments\n"
470 "# a commented line\n"
471 "algo some-key another\n";
472 g_autoptr(GuestAuthorizedKeys) ret = NULL;
473 strList *k;
474 size_t len = 0;
475
476 test_authorized_keys_set(authkeys);
477
478 ret = qmp_guest_ssh_get_authorized_keys(g_get_user_name(), &err);
479 g_assert(err == NULL);
480
481 for (len = 0, k = ret->keys; k != NULL; k = k->next) {
482 g_assert(g_str_has_prefix(k->value, "algo "));
483 len++;
484 }
485
486 g_assert(len == 2);
487 }
488
489 int main(int argc, char *argv[])
490 {
491 setlocale(LC_ALL, "");
492
493 g_test_init(&argc, &argv, G_TEST_OPTION_ISOLATE_DIRS, NULL);
494
495 g_test_add_func("/qga/ssh/invalid_user", test_invalid_user);
496 g_test_add_func("/qga/ssh/invalid_key", test_invalid_key);
497 g_test_add_func("/qga/ssh/add_keys", test_add_keys);
498 g_test_add_func("/qga/ssh/add_reset_keys", test_add_reset_keys);
499 g_test_add_func("/qga/ssh/remove_keys", test_remove_keys);
500 g_test_add_func("/qga/ssh/get_keys", test_get_keys);
501
502 return g_test_run();
503 }
504 #else
505 int main(int argc, char *argv[])
506 {
507 g_test_message("test skipped, needs glib >= 2.60");
508 return 0;
509 }
510 #endif /* GLIB_2_60 */
511 #endif /* BUILD_UNIT_TEST */