commands-posix-ssh.c (12997B)
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 p = g_unix_get_passwd_entry_qemu(username, &err); 49 if (p == NULL) { 50 error_setg(errp, "failed to lookup user '%s': %s", 51 username, err->message); 52 return NULL; 53 } 54 55 return p; 56 } 57 58 static bool 59 mkdir_for_user(const char *path, const struct passwd *p, 60 mode_t mode, Error **errp) 61 { 62 if (g_mkdir(path, mode) == -1) { 63 error_setg(errp, "failed to create directory '%s': %s", 64 path, g_strerror(errno)); 65 return false; 66 } 67 68 if (chown(path, p->pw_uid, p->pw_gid) == -1) { 69 error_setg(errp, "failed to set ownership of directory '%s': %s", 70 path, g_strerror(errno)); 71 return false; 72 } 73 74 if (chmod(path, mode) == -1) { 75 error_setg(errp, "failed to set permissions of directory '%s': %s", 76 path, g_strerror(errno)); 77 return false; 78 } 79 80 return true; 81 } 82 83 static bool 84 check_openssh_pub_key(const char *key, Error **errp) 85 { 86 /* simple sanity-check, we may want more? */ 87 if (!key || key[0] == '#' || strchr(key, '\n')) { 88 error_setg(errp, "invalid OpenSSH public key: '%s'", key); 89 return false; 90 } 91 92 return true; 93 } 94 95 static bool 96 check_openssh_pub_keys(strList *keys, size_t *nkeys, Error **errp) 97 { 98 size_t n = 0; 99 strList *k; 100 101 for (k = keys; k != NULL; k = k->next) { 102 if (!check_openssh_pub_key(k->value, errp)) { 103 return false; 104 } 105 n++; 106 } 107 108 if (nkeys) { 109 *nkeys = n; 110 } 111 return true; 112 } 113 114 static bool 115 write_authkeys(const char *path, const GStrv keys, 116 const struct passwd *p, Error **errp) 117 { 118 g_autofree char *contents = NULL; 119 g_autoptr(GError) err = NULL; 120 121 contents = g_strjoinv("\n", keys); 122 if (!g_file_set_contents(path, contents, -1, &err)) { 123 error_setg(errp, "failed to write to '%s': %s", path, err->message); 124 return false; 125 } 126 127 if (chown(path, p->pw_uid, p->pw_gid) == -1) { 128 error_setg(errp, "failed to set ownership of directory '%s': %s", 129 path, g_strerror(errno)); 130 return false; 131 } 132 133 if (chmod(path, 0600) == -1) { 134 error_setg(errp, "failed to set permissions of '%s': %s", 135 path, g_strerror(errno)); 136 return false; 137 } 138 139 return true; 140 } 141 142 static GStrv 143 read_authkeys(const char *path, Error **errp) 144 { 145 g_autoptr(GError) err = NULL; 146 g_autofree char *contents = NULL; 147 148 if (!g_file_get_contents(path, &contents, NULL, &err)) { 149 error_setg(errp, "failed to read '%s': %s", path, err->message); 150 return NULL; 151 } 152 153 return g_strsplit(contents, "\n", -1); 154 155 } 156 157 void 158 qmp_guest_ssh_add_authorized_keys(const char *username, strList *keys, 159 bool has_reset, bool reset, 160 Error **errp) 161 { 162 g_autofree struct passwd *p = NULL; 163 g_autofree char *ssh_path = NULL; 164 g_autofree char *authkeys_path = NULL; 165 g_auto(GStrv) authkeys = NULL; 166 strList *k; 167 size_t nkeys, nauthkeys; 168 169 reset = has_reset && reset; 170 171 if (!check_openssh_pub_keys(keys, &nkeys, errp)) { 172 return; 173 } 174 175 p = get_passwd_entry(username, errp); 176 if (p == NULL) { 177 return; 178 } 179 180 ssh_path = g_build_filename(p->pw_dir, ".ssh", NULL); 181 authkeys_path = g_build_filename(ssh_path, "authorized_keys", NULL); 182 183 if (!reset) { 184 authkeys = read_authkeys(authkeys_path, NULL); 185 } 186 if (authkeys == NULL) { 187 if (!g_file_test(ssh_path, G_FILE_TEST_IS_DIR) && 188 !mkdir_for_user(ssh_path, p, 0700, errp)) { 189 return; 190 } 191 } 192 193 nauthkeys = authkeys ? g_strv_length(authkeys) : 0; 194 authkeys = g_realloc_n(authkeys, nauthkeys + nkeys + 1, sizeof(char *)); 195 memset(authkeys + nauthkeys, 0, (nkeys + 1) * sizeof(char *)); 196 197 for (k = keys; k != NULL; k = k->next) { 198 if (g_strv_contains((const gchar * const *)authkeys, k->value)) { 199 continue; 200 } 201 authkeys[nauthkeys++] = g_strdup(k->value); 202 } 203 204 write_authkeys(authkeys_path, authkeys, p, errp); 205 } 206 207 void 208 qmp_guest_ssh_remove_authorized_keys(const char *username, strList *keys, 209 Error **errp) 210 { 211 g_autofree struct passwd *p = NULL; 212 g_autofree char *authkeys_path = NULL; 213 g_autofree GStrv new_keys = NULL; /* do not own the strings */ 214 g_auto(GStrv) authkeys = NULL; 215 GStrv a; 216 size_t nkeys = 0; 217 218 if (!check_openssh_pub_keys(keys, NULL, errp)) { 219 return; 220 } 221 222 p = get_passwd_entry(username, errp); 223 if (p == NULL) { 224 return; 225 } 226 227 authkeys_path = g_build_filename(p->pw_dir, ".ssh", 228 "authorized_keys", NULL); 229 if (!g_file_test(authkeys_path, G_FILE_TEST_EXISTS)) { 230 return; 231 } 232 authkeys = read_authkeys(authkeys_path, errp); 233 if (authkeys == NULL) { 234 return; 235 } 236 237 new_keys = g_new0(char *, g_strv_length(authkeys) + 1); 238 for (a = authkeys; *a != NULL; a++) { 239 strList *k; 240 241 for (k = keys; k != NULL; k = k->next) { 242 if (g_str_equal(k->value, *a)) { 243 break; 244 } 245 } 246 if (k != NULL) { 247 continue; 248 } 249 250 new_keys[nkeys++] = *a; 251 } 252 253 write_authkeys(authkeys_path, new_keys, p, errp); 254 } 255 256 GuestAuthorizedKeys * 257 qmp_guest_ssh_get_authorized_keys(const char *username, Error **errp) 258 { 259 g_autofree struct passwd *p = NULL; 260 g_autofree char *authkeys_path = NULL; 261 g_auto(GStrv) authkeys = NULL; 262 g_autoptr(GuestAuthorizedKeys) ret = NULL; 263 int i; 264 265 p = get_passwd_entry(username, errp); 266 if (p == NULL) { 267 return NULL; 268 } 269 270 authkeys_path = g_build_filename(p->pw_dir, ".ssh", 271 "authorized_keys", NULL); 272 authkeys = read_authkeys(authkeys_path, errp); 273 if (authkeys == NULL) { 274 return NULL; 275 } 276 277 ret = g_new0(GuestAuthorizedKeys, 1); 278 for (i = 0; authkeys[i] != NULL; i++) { 279 g_strstrip(authkeys[i]); 280 if (!authkeys[i][0] || authkeys[i][0] == '#') { 281 continue; 282 } 283 284 QAPI_LIST_PREPEND(ret->keys, g_strdup(authkeys[i])); 285 } 286 287 return g_steal_pointer(&ret); 288 } 289 290 #ifdef QGA_BUILD_UNIT_TEST 291 #if GLIB_CHECK_VERSION(2, 60, 0) 292 static const strList test_key2 = { 293 .value = (char *)"algo key2 comments" 294 }; 295 296 static const strList test_key1_2 = { 297 .value = (char *)"algo key1 comments", 298 .next = (strList *)&test_key2, 299 }; 300 301 static char * 302 test_get_authorized_keys_path(void) 303 { 304 return g_build_filename(g_get_home_dir(), ".ssh", "authorized_keys", NULL); 305 } 306 307 static void 308 test_authorized_keys_set(const char *contents) 309 { 310 g_autoptr(GError) err = NULL; 311 g_autofree char *path = NULL; 312 int ret; 313 314 path = g_build_filename(g_get_home_dir(), ".ssh", NULL); 315 ret = g_mkdir_with_parents(path, 0700); 316 g_assert(ret == 0); 317 g_free(path); 318 319 path = test_get_authorized_keys_path(); 320 g_file_set_contents(path, contents, -1, &err); 321 g_assert(err == NULL); 322 } 323 324 static void 325 test_authorized_keys_equal(const char *expected) 326 { 327 g_autoptr(GError) err = NULL; 328 g_autofree char *path = NULL; 329 g_autofree char *contents = NULL; 330 331 path = test_get_authorized_keys_path(); 332 g_file_get_contents(path, &contents, NULL, &err); 333 g_assert(err == NULL); 334 335 g_assert(g_strcmp0(contents, expected) == 0); 336 } 337 338 static void 339 test_invalid_user(void) 340 { 341 Error *err = NULL; 342 343 qmp_guest_ssh_add_authorized_keys("", NULL, FALSE, FALSE, &err); 344 error_free_or_abort(&err); 345 346 qmp_guest_ssh_remove_authorized_keys("", NULL, &err); 347 error_free_or_abort(&err); 348 } 349 350 static void 351 test_invalid_key(void) 352 { 353 strList key = { 354 .value = (char *)"not a valid\nkey" 355 }; 356 Error *err = NULL; 357 358 qmp_guest_ssh_add_authorized_keys(g_get_user_name(), &key, 359 FALSE, FALSE, &err); 360 error_free_or_abort(&err); 361 362 qmp_guest_ssh_remove_authorized_keys(g_get_user_name(), &key, &err); 363 error_free_or_abort(&err); 364 } 365 366 static void 367 test_add_keys(void) 368 { 369 Error *err = NULL; 370 371 qmp_guest_ssh_add_authorized_keys(g_get_user_name(), 372 (strList *)&test_key2, 373 FALSE, FALSE, 374 &err); 375 g_assert(err == NULL); 376 377 test_authorized_keys_equal("algo key2 comments"); 378 379 qmp_guest_ssh_add_authorized_keys(g_get_user_name(), 380 (strList *)&test_key1_2, 381 FALSE, FALSE, 382 &err); 383 g_assert(err == NULL); 384 385 /* key2 came first, and should'nt be duplicated */ 386 test_authorized_keys_equal("algo key2 comments\n" 387 "algo key1 comments"); 388 } 389 390 static void 391 test_add_reset_keys(void) 392 { 393 Error *err = NULL; 394 395 qmp_guest_ssh_add_authorized_keys(g_get_user_name(), 396 (strList *)&test_key1_2, 397 FALSE, FALSE, 398 &err); 399 g_assert(err == NULL); 400 401 /* reset with key2 only */ 402 test_authorized_keys_equal("algo key1 comments\n" 403 "algo key2 comments"); 404 405 qmp_guest_ssh_add_authorized_keys(g_get_user_name(), 406 (strList *)&test_key2, 407 TRUE, TRUE, 408 &err); 409 g_assert(err == NULL); 410 411 test_authorized_keys_equal("algo key2 comments"); 412 413 /* empty should clear file */ 414 qmp_guest_ssh_add_authorized_keys(g_get_user_name(), 415 (strList *)NULL, 416 TRUE, TRUE, 417 &err); 418 g_assert(err == NULL); 419 420 test_authorized_keys_equal(""); 421 } 422 423 static void 424 test_remove_keys(void) 425 { 426 Error *err = NULL; 427 static const char *authkeys = 428 "algo key1 comments\n" 429 /* originally duplicated */ 430 "algo key1 comments\n" 431 "# a commented line\n" 432 "algo some-key another\n"; 433 434 test_authorized_keys_set(authkeys); 435 qmp_guest_ssh_remove_authorized_keys(g_get_user_name(), 436 (strList *)&test_key2, &err); 437 g_assert(err == NULL); 438 test_authorized_keys_equal(authkeys); 439 440 qmp_guest_ssh_remove_authorized_keys(g_get_user_name(), 441 (strList *)&test_key1_2, &err); 442 g_assert(err == NULL); 443 test_authorized_keys_equal("# a commented line\n" 444 "algo some-key another\n"); 445 } 446 447 static void 448 test_get_keys(void) 449 { 450 Error *err = NULL; 451 static const char *authkeys = 452 "algo key1 comments\n" 453 "# a commented line\n" 454 "algo some-key another\n"; 455 g_autoptr(GuestAuthorizedKeys) ret = NULL; 456 strList *k; 457 size_t len = 0; 458 459 test_authorized_keys_set(authkeys); 460 461 ret = qmp_guest_ssh_get_authorized_keys(g_get_user_name(), &err); 462 g_assert(err == NULL); 463 464 for (len = 0, k = ret->keys; k != NULL; k = k->next) { 465 g_assert(g_str_has_prefix(k->value, "algo ")); 466 len++; 467 } 468 469 g_assert(len == 2); 470 } 471 472 int main(int argc, char *argv[]) 473 { 474 setlocale(LC_ALL, ""); 475 476 g_test_init(&argc, &argv, G_TEST_OPTION_ISOLATE_DIRS, NULL); 477 478 g_test_add_func("/qga/ssh/invalid_user", test_invalid_user); 479 g_test_add_func("/qga/ssh/invalid_key", test_invalid_key); 480 g_test_add_func("/qga/ssh/add_keys", test_add_keys); 481 g_test_add_func("/qga/ssh/add_reset_keys", test_add_reset_keys); 482 g_test_add_func("/qga/ssh/remove_keys", test_remove_keys); 483 g_test_add_func("/qga/ssh/get_keys", test_get_keys); 484 485 return g_test_run(); 486 } 487 #else 488 int main(int argc, char *argv[]) 489 { 490 g_test_message("test skipped, needs glib >= 2.60"); 491 return 0; 492 } 493 #endif /* GLIB_2_60 */ 494 #endif /* BUILD_UNIT_TEST */