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26cf9fb7 LP |
1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
2 | ||
3 | #include <security/pam_ext.h> | |
4 | #include <security/pam_modules.h> | |
5 | ||
6 | #include "sd-bus.h" | |
7 | ||
8 | #include "bus-common-errors.h" | |
ea7cbf5b | 9 | #include "bus-util.h" |
26cf9fb7 LP |
10 | #include "errno-util.h" |
11 | #include "fd-util.h" | |
12 | #include "home-util.h" | |
13 | #include "memory-util.h" | |
14 | #include "pam-util.h" | |
15 | #include "parse-util.h" | |
16 | #include "strv.h" | |
17 | #include "user-record-util.h" | |
18 | #include "user-record.h" | |
19 | #include "user-util.h" | |
20 | ||
21 | /* Used for the "systemd-user-record-is-homed" PAM data field, to indicate whether we know whether this user | |
22 | * record is managed by homed or by something else. */ | |
23 | #define USER_RECORD_IS_HOMED INT_TO_PTR(1) | |
24 | #define USER_RECORD_IS_OTHER INT_TO_PTR(2) | |
25 | ||
ea7cbf5b VC |
26 | static const BusLocator home_mgr = { |
27 | .destination = "org.freedesktop.home1", | |
28 | .path = "/org/freedesktop/home1", | |
29 | .interface = "org.freedesktop.home1.Manager", | |
30 | }; | |
31 | ||
26cf9fb7 LP |
32 | static int parse_argv( |
33 | pam_handle_t *handle, | |
34 | int argc, const char **argv, | |
35 | bool *please_suspend, | |
36 | bool *debug) { | |
37 | ||
38 | int i; | |
39 | ||
40 | assert(argc >= 0); | |
41 | assert(argc == 0 || argv); | |
42 | ||
43 | for (i = 0; i < argc; i++) { | |
44 | const char *v; | |
45 | ||
f12d19b3 | 46 | if ((v = startswith(argv[i], "suspend="))) { |
26cf9fb7 LP |
47 | int k; |
48 | ||
49 | k = parse_boolean(v); | |
50 | if (k < 0) | |
80ace4f2 | 51 | pam_syslog(handle, LOG_WARNING, "Failed to parse suspend= argument, ignoring: %s", v); |
26cf9fb7 LP |
52 | else if (please_suspend) |
53 | *please_suspend = k; | |
54 | ||
55 | } else if ((v = startswith(argv[i], "debug="))) { | |
56 | int k; | |
57 | ||
58 | k = parse_boolean(v); | |
59 | if (k < 0) | |
60 | pam_syslog(handle, LOG_WARNING, "Failed to parse debug= argument, ignoring: %s", v); | |
61 | else if (debug) | |
62 | *debug = k; | |
63 | ||
64 | } else | |
65 | pam_syslog(handle, LOG_WARNING, "Unknown parameter '%s', ignoring", argv[i]); | |
66 | } | |
67 | ||
68 | return 0; | |
69 | } | |
70 | ||
71 | static int acquire_user_record( | |
72 | pam_handle_t *handle, | |
73 | UserRecord **ret_record) { | |
74 | ||
75 | _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; | |
76 | _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; | |
77 | _cleanup_(user_record_unrefp) UserRecord *ur = NULL; | |
78 | _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; | |
79 | const char *username = NULL, *json = NULL; | |
80 | const void *b = NULL; | |
81 | int r; | |
82 | ||
83 | assert(handle); | |
84 | ||
85 | r = pam_get_user(handle, &username, NULL); | |
86 | if (r != PAM_SUCCESS) { | |
87 | pam_syslog(handle, LOG_ERR, "Failed to get user name: %s", pam_strerror(handle, r)); | |
88 | return r; | |
89 | } | |
90 | ||
91 | if (isempty(username)) { | |
92 | pam_syslog(handle, LOG_ERR, "User name not set."); | |
93 | return PAM_SERVICE_ERR; | |
94 | } | |
95 | ||
96 | /* Let's bypass all IPC complexity for the two user names we know for sure we don't manage, and for | |
97 | * user names we don't consider valid. */ | |
7a8867ab | 98 | if (STR_IN_SET(username, "root", NOBODY_USER_NAME) || !valid_user_group_name(username, 0)) |
26cf9fb7 LP |
99 | return PAM_USER_UNKNOWN; |
100 | ||
101 | /* Let's check if a previous run determined that this user is not managed by homed. If so, let's exit early */ | |
102 | r = pam_get_data(handle, "systemd-user-record-is-homed", &b); | |
103 | if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) { | |
104 | /* Failure */ | |
80ace4f2 | 105 | pam_syslog(handle, LOG_ERR, "Failed to get PAM user-record-is-homed flag: %s", pam_strerror(handle, r)); |
26cf9fb7 LP |
106 | return r; |
107 | } else if (b == NULL) | |
108 | /* Nothing cached yet, need to acquire fresh */ | |
109 | json = NULL; | |
110 | else if (b != USER_RECORD_IS_HOMED) | |
111 | /* Definitely not a homed record */ | |
112 | return PAM_USER_UNKNOWN; | |
113 | else { | |
114 | /* It's a homed record, let's use the cache, so that we can share it between the session and | |
115 | * the authentication hooks */ | |
116 | r = pam_get_data(handle, "systemd-user-record", (const void**) &json); | |
117 | if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) { | |
118 | pam_syslog(handle, LOG_ERR, "Failed to get PAM user record data: %s", pam_strerror(handle, r)); | |
119 | return r; | |
120 | } | |
121 | } | |
122 | ||
123 | if (!json) { | |
124 | _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; | |
125 | _cleanup_free_ char *json_copy = NULL; | |
126 | ||
127 | r = pam_acquire_bus_connection(handle, &bus); | |
128 | if (r != PAM_SUCCESS) | |
129 | return r; | |
130 | ||
ea7cbf5b | 131 | r = bus_call_method(bus, &home_mgr, "GetUserRecordByName", &error, &reply, "s", username); |
26cf9fb7 LP |
132 | if (r < 0) { |
133 | if (sd_bus_error_has_name(&error, SD_BUS_ERROR_SERVICE_UNKNOWN) || | |
134 | sd_bus_error_has_name(&error, SD_BUS_ERROR_NAME_HAS_NO_OWNER)) { | |
135 | pam_syslog(handle, LOG_DEBUG, "systemd-homed is not available: %s", bus_error_message(&error, r)); | |
136 | goto user_unknown; | |
137 | } | |
138 | ||
139 | if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_HOME)) { | |
140 | pam_syslog(handle, LOG_DEBUG, "Not a user managed by systemd-homed: %s", bus_error_message(&error, r)); | |
141 | goto user_unknown; | |
142 | } | |
143 | ||
144 | pam_syslog(handle, LOG_ERR, "Failed to query user record: %s", bus_error_message(&error, r)); | |
145 | return PAM_SERVICE_ERR; | |
146 | } | |
147 | ||
148 | r = sd_bus_message_read(reply, "sbo", &json, NULL, NULL); | |
149 | if (r < 0) | |
150 | return pam_bus_log_parse_error(handle, r); | |
151 | ||
152 | json_copy = strdup(json); | |
153 | if (!json_copy) | |
154 | return pam_log_oom(handle); | |
155 | ||
156 | r = pam_set_data(handle, "systemd-user-record", json_copy, pam_cleanup_free); | |
157 | if (r != PAM_SUCCESS) { | |
158 | pam_syslog(handle, LOG_ERR, "Failed to set PAM user record data: %s", pam_strerror(handle, r)); | |
159 | return r; | |
160 | } | |
161 | ||
162 | TAKE_PTR(json_copy); | |
163 | ||
164 | r = pam_set_data(handle, "systemd-user-record-is-homed", USER_RECORD_IS_HOMED, NULL); | |
165 | if (r != PAM_SUCCESS) { | |
166 | pam_syslog(handle, LOG_ERR, "Failed to set PAM user record is homed flag: %s", pam_strerror(handle, r)); | |
167 | return r; | |
168 | } | |
169 | } | |
170 | ||
171 | r = json_parse(json, JSON_PARSE_SENSITIVE, &v, NULL, NULL); | |
172 | if (r < 0) { | |
173 | pam_syslog(handle, LOG_ERR, "Failed to parse JSON user record: %s", strerror_safe(r)); | |
174 | return PAM_SERVICE_ERR; | |
175 | } | |
176 | ||
177 | ur = user_record_new(); | |
178 | if (!ur) | |
179 | return pam_log_oom(handle); | |
180 | ||
181 | r = user_record_load(ur, v, USER_RECORD_LOAD_REFUSE_SECRET); | |
182 | if (r < 0) { | |
183 | pam_syslog(handle, LOG_ERR, "Failed to load user record: %s", strerror_safe(r)); | |
184 | return PAM_SERVICE_ERR; | |
185 | } | |
186 | ||
187 | if (!streq_ptr(username, ur->user_name)) { | |
188 | pam_syslog(handle, LOG_ERR, "Acquired user record does not match user name."); | |
189 | return PAM_SERVICE_ERR; | |
190 | } | |
191 | ||
192 | if (ret_record) | |
193 | *ret_record = TAKE_PTR(ur); | |
194 | ||
195 | return PAM_SUCCESS; | |
196 | ||
197 | user_unknown: | |
198 | /* Cache this, so that we don't check again */ | |
199 | r = pam_set_data(handle, "systemd-user-record-is-homed", USER_RECORD_IS_OTHER, NULL); | |
200 | if (r != PAM_SUCCESS) | |
80ace4f2 | 201 | pam_syslog(handle, LOG_ERR, "Failed to set PAM user-record-is-homed flag, ignoring: %s", pam_strerror(handle, r)); |
26cf9fb7 LP |
202 | |
203 | return PAM_USER_UNKNOWN; | |
204 | } | |
205 | ||
206 | static int release_user_record(pam_handle_t *handle) { | |
207 | int r, k; | |
208 | ||
209 | r = pam_set_data(handle, "systemd-user-record", NULL, NULL); | |
210 | if (r != PAM_SUCCESS) | |
211 | pam_syslog(handle, LOG_ERR, "Failed to release PAM user record data: %s", pam_strerror(handle, r)); | |
212 | ||
213 | k = pam_set_data(handle, "systemd-user-record-is-homed", NULL, NULL); | |
214 | if (k != PAM_SUCCESS) | |
80ace4f2 | 215 | pam_syslog(handle, LOG_ERR, "Failed to release PAM user-record-is-homed flag: %s", pam_strerror(handle, k)); |
26cf9fb7 LP |
216 | |
217 | return IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA) ? k : r; | |
218 | } | |
219 | ||
220 | static void cleanup_home_fd(pam_handle_t *handle, void *data, int error_status) { | |
221 | safe_close(PTR_TO_FD(data)); | |
222 | } | |
223 | ||
224 | static int handle_generic_user_record_error( | |
225 | pam_handle_t *handle, | |
226 | const char *user_name, | |
227 | UserRecord *secret, | |
228 | int ret, | |
229 | const sd_bus_error *error) { | |
230 | ||
231 | assert(user_name); | |
232 | assert(secret); | |
233 | assert(error); | |
234 | ||
235 | int r; | |
236 | ||
237 | /* Logs about all errors, except for PAM_CONV_ERR, i.e. when requesting more info failed. */ | |
238 | ||
239 | if (sd_bus_error_has_name(error, BUS_ERROR_HOME_ABSENT)) { | |
240 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Home of user %s is currently absent, please plug in the necessary storage device or backing file system.", user_name); | |
241 | pam_syslog(handle, LOG_ERR, "Failed to acquire home for user %s: %s", user_name, bus_error_message(error, ret)); | |
242 | return PAM_PERM_DENIED; | |
243 | ||
244 | } else if (sd_bus_error_has_name(error, BUS_ERROR_AUTHENTICATION_LIMIT_HIT)) { | |
245 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Too frequent unsuccessful login attempts for user %s, try again later.", user_name); | |
246 | pam_syslog(handle, LOG_ERR, "Failed to acquire home for user %s: %s", user_name, bus_error_message(error, ret)); | |
247 | return PAM_MAXTRIES; | |
248 | ||
249 | } else if (sd_bus_error_has_name(error, BUS_ERROR_BAD_PASSWORD)) { | |
250 | _cleanup_(erase_and_freep) char *newp = NULL; | |
251 | ||
252 | /* This didn't work? Ask for an (additional?) password */ | |
253 | ||
254 | if (strv_isempty(secret->password)) | |
255 | r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Password: "); | |
256 | else | |
257 | r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Password incorrect or not sufficient for authentication of user %s, please try again: ", user_name); | |
258 | if (r != PAM_SUCCESS) | |
259 | return PAM_CONV_ERR; /* no logging here */ | |
260 | ||
261 | if (isempty(newp)) { | |
262 | pam_syslog(handle, LOG_DEBUG, "Password request aborted."); | |
263 | return PAM_AUTHTOK_ERR; | |
264 | } | |
265 | ||
266 | r = user_record_set_password(secret, STRV_MAKE(newp), true); | |
267 | if (r < 0) { | |
268 | pam_syslog(handle, LOG_ERR, "Failed to store password: %s", strerror_safe(r)); | |
269 | return PAM_SERVICE_ERR; | |
270 | } | |
271 | ||
272 | } else if (sd_bus_error_has_name(error, BUS_ERROR_BAD_PASSWORD_AND_NO_TOKEN)) { | |
273 | _cleanup_(erase_and_freep) char *newp = NULL; | |
274 | ||
275 | if (strv_isempty(secret->password)) | |
276 | r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Security token of user %s not inserted, please enter password: ", user_name); | |
277 | else | |
278 | r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Password incorrect or not sufficient, and configured security token of user %s not inserted, please enter password: ", user_name); | |
279 | if (r != PAM_SUCCESS) | |
280 | return PAM_CONV_ERR; /* no logging here */ | |
281 | ||
282 | if (isempty(newp)) { | |
283 | pam_syslog(handle, LOG_DEBUG, "Password request aborted."); | |
284 | return PAM_AUTHTOK_ERR; | |
285 | } | |
286 | ||
287 | r = user_record_set_password(secret, STRV_MAKE(newp), true); | |
288 | if (r < 0) { | |
289 | pam_syslog(handle, LOG_ERR, "Failed to store password: %s", strerror_safe(r)); | |
290 | return PAM_SERVICE_ERR; | |
291 | } | |
292 | ||
293 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_PIN_NEEDED)) { | |
294 | _cleanup_(erase_and_freep) char *newp = NULL; | |
295 | ||
296 | r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Please enter security token PIN: "); | |
297 | if (r != PAM_SUCCESS) | |
298 | return PAM_CONV_ERR; /* no logging here */ | |
299 | ||
300 | if (isempty(newp)) { | |
301 | pam_syslog(handle, LOG_DEBUG, "PIN request aborted."); | |
302 | return PAM_AUTHTOK_ERR; | |
303 | } | |
304 | ||
305 | r = user_record_set_pkcs11_pin(secret, STRV_MAKE(newp), false); | |
306 | if (r < 0) { | |
307 | pam_syslog(handle, LOG_ERR, "Failed to store PIN: %s", strerror_safe(r)); | |
308 | return PAM_SERVICE_ERR; | |
309 | } | |
310 | ||
311 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_PROTECTED_AUTHENTICATION_PATH_NEEDED)) { | |
312 | ||
313 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Please authenticate physically on security token of user %s.", user_name); | |
314 | ||
315 | r = user_record_set_pkcs11_protected_authentication_path_permitted(secret, true); | |
316 | if (r < 0) { | |
317 | pam_syslog(handle, LOG_ERR, "Failed to set PKCS#11 protected authentication path permitted flag: %s", strerror_safe(r)); | |
318 | return PAM_SERVICE_ERR; | |
319 | } | |
320 | ||
321 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_BAD_PIN)) { | |
322 | _cleanup_(erase_and_freep) char *newp = NULL; | |
323 | ||
324 | r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Security token PIN incorrect, please enter PIN for security token of user %s again: ", user_name); | |
325 | if (r != PAM_SUCCESS) | |
326 | return PAM_CONV_ERR; /* no logging here */ | |
327 | ||
328 | if (isempty(newp)) { | |
329 | pam_syslog(handle, LOG_DEBUG, "PIN request aborted."); | |
330 | return PAM_AUTHTOK_ERR; | |
331 | } | |
332 | ||
333 | r = user_record_set_pkcs11_pin(secret, STRV_MAKE(newp), false); | |
334 | if (r < 0) { | |
335 | pam_syslog(handle, LOG_ERR, "Failed to store PIN: %s", strerror_safe(r)); | |
336 | return PAM_SERVICE_ERR; | |
337 | } | |
338 | ||
339 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_BAD_PIN_FEW_TRIES_LEFT)) { | |
340 | _cleanup_(erase_and_freep) char *newp = NULL; | |
341 | ||
342 | r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Security token PIN incorrect (only a few tries left!), please enter PIN for security token of user %s again: ", user_name); | |
343 | if (r != PAM_SUCCESS) | |
344 | return PAM_CONV_ERR; /* no logging here */ | |
345 | ||
346 | if (isempty(newp)) { | |
347 | pam_syslog(handle, LOG_DEBUG, "PIN request aborted."); | |
348 | return PAM_AUTHTOK_ERR; | |
349 | } | |
350 | ||
351 | r = user_record_set_pkcs11_pin(secret, STRV_MAKE(newp), false); | |
352 | if (r < 0) { | |
353 | pam_syslog(handle, LOG_ERR, "Failed to store PIN: %s", strerror_safe(r)); | |
354 | return PAM_SERVICE_ERR; | |
355 | } | |
356 | ||
357 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_BAD_PIN_ONE_TRY_LEFT)) { | |
358 | _cleanup_(erase_and_freep) char *newp = NULL; | |
359 | ||
360 | r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Security token PIN incorrect (only one try left!), please enter PIN for security token of user %s again: ", user_name); | |
361 | if (r != PAM_SUCCESS) | |
362 | return PAM_CONV_ERR; /* no logging here */ | |
363 | ||
364 | if (isempty(newp)) { | |
365 | pam_syslog(handle, LOG_DEBUG, "PIN request aborted."); | |
366 | return PAM_AUTHTOK_ERR; | |
367 | } | |
368 | ||
369 | r = user_record_set_pkcs11_pin(secret, STRV_MAKE(newp), false); | |
370 | if (r < 0) { | |
371 | pam_syslog(handle, LOG_ERR, "Failed to store PIN: %s", strerror_safe(r)); | |
372 | return PAM_SERVICE_ERR; | |
373 | } | |
374 | ||
375 | } else { | |
376 | pam_syslog(handle, LOG_ERR, "Failed to acquire home for user %s: %s", user_name, bus_error_message(error, ret)); | |
377 | return PAM_SERVICE_ERR; | |
378 | } | |
379 | ||
380 | return PAM_SUCCESS; | |
381 | } | |
382 | ||
383 | static int acquire_home( | |
384 | pam_handle_t *handle, | |
385 | bool please_authenticate, | |
386 | bool please_suspend, | |
387 | bool debug) { | |
388 | ||
389 | _cleanup_(user_record_unrefp) UserRecord *ur = NULL, *secret = NULL; | |
390 | bool do_auth = please_authenticate, home_not_active = false, home_locked = false; | |
391 | _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; | |
392 | _cleanup_close_ int acquired_fd = -1; | |
393 | const void *home_fd_ptr = NULL; | |
394 | unsigned n_attempts = 0; | |
395 | int r; | |
396 | ||
397 | assert(handle); | |
398 | ||
399 | /* This acquires a reference to a home directory in one of two ways: if please_authenticate is true, | |
400 | * then we'll call AcquireHome() after asking the user for a password. Otherwise it tries to call | |
401 | * RefHome() and if that fails queries the user for a password and uses AcquireHome(). | |
402 | * | |
403 | * The idea is that the PAM authentication hook sets please_authenticate and thus always | |
404 | * authenticates, while the other PAM hooks unset it so that they can a ref of their own without | |
405 | * authentication if possible, but with authentication if necessary. */ | |
406 | ||
407 | /* If we already have acquired the fd, let's shortcut this */ | |
408 | r = pam_get_data(handle, "systemd-home-fd", &home_fd_ptr); | |
409 | if (r == PAM_SUCCESS && PTR_TO_INT(home_fd_ptr) >= 0) | |
410 | return PAM_SUCCESS; | |
411 | ||
412 | r = pam_acquire_bus_connection(handle, &bus); | |
413 | if (r != PAM_SUCCESS) | |
414 | return r; | |
415 | ||
416 | r = acquire_user_record(handle, &ur); | |
417 | if (r != PAM_SUCCESS) | |
418 | return r; | |
419 | ||
420 | /* Implement our own retry loop here instead of relying on the PAM client's one. That's because it | |
421 | * might happen that the the record we stored on the host does not match the encryption password of | |
422 | * the LUKS image in case the image was used in a different system where the password was | |
423 | * changed. In that case it will happen that the LUKS password and the host password are | |
424 | * different, and we handle that by collecting and passing multiple passwords in that case. Hence we | |
425 | * treat bad passwords as a request to collect one more password and pass the new all all previously | |
426 | * used passwords again. */ | |
427 | ||
428 | for (;;) { | |
429 | _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL, *reply = NULL; | |
430 | _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; | |
431 | ||
432 | if (do_auth && !secret) { | |
433 | const char *cached_password = NULL; | |
434 | ||
435 | secret = user_record_new(); | |
436 | if (!secret) | |
437 | return pam_log_oom(handle); | |
438 | ||
439 | /* If there's already a cached password, use it. But if not let's authenticate | |
440 | * without anything, maybe some other authentication mechanism systemd-homed | |
441 | * implements (such as PKCS#11) allows us to authenticate without anything else. */ | |
442 | r = pam_get_item(handle, PAM_AUTHTOK, (const void**) &cached_password); | |
443 | if (!IN_SET(r, PAM_BAD_ITEM, PAM_SUCCESS)) { | |
444 | pam_syslog(handle, LOG_ERR, "Failed to get cached password: %s", pam_strerror(handle, r)); | |
445 | return r; | |
446 | } | |
447 | ||
448 | if (!isempty(cached_password)) { | |
449 | r = user_record_set_password(secret, STRV_MAKE(cached_password), true); | |
450 | if (r < 0) { | |
451 | pam_syslog(handle, LOG_ERR, "Failed to store password: %s", strerror_safe(r)); | |
452 | return PAM_SERVICE_ERR; | |
453 | } | |
454 | } | |
455 | } | |
456 | ||
ea7cbf5b | 457 | r = bus_message_new_method_call(bus, &m, &home_mgr, do_auth ? "AcquireHome" : "RefHome"); |
26cf9fb7 LP |
458 | if (r < 0) |
459 | return pam_bus_log_create_error(handle, r); | |
460 | ||
461 | r = sd_bus_message_append(m, "s", ur->user_name); | |
462 | if (r < 0) | |
463 | return pam_bus_log_create_error(handle, r); | |
464 | ||
465 | if (do_auth) { | |
466 | r = bus_message_append_secret(m, secret); | |
467 | if (r < 0) | |
468 | return pam_bus_log_create_error(handle, r); | |
469 | } | |
470 | ||
471 | r = sd_bus_message_append(m, "b", please_suspend); | |
472 | if (r < 0) | |
473 | return pam_bus_log_create_error(handle, r); | |
474 | ||
475 | r = sd_bus_call(bus, m, HOME_SLOW_BUS_CALL_TIMEOUT_USEC, &error, &reply); | |
476 | if (r < 0) { | |
477 | ||
478 | if (sd_bus_error_has_name(&error, BUS_ERROR_HOME_NOT_ACTIVE)) | |
479 | /* Only on RefHome(): We can't access the home directory currently, unless | |
480 | * it's unlocked with a password. Hence, let's try this again, this time with | |
481 | * authentication. */ | |
482 | home_not_active = true; | |
483 | else if (sd_bus_error_has_name(&error, BUS_ERROR_HOME_LOCKED)) | |
484 | home_locked = true; /* Similar */ | |
485 | else { | |
486 | r = handle_generic_user_record_error(handle, ur->user_name, secret, r, &error); | |
487 | if (r == PAM_CONV_ERR) { | |
488 | /* Password/PIN prompts will fail in certain environments, for example when | |
489 | * we are called from OpenSSH's account or session hooks, or in systemd's | |
490 | * per-service PAM logic. In that case, print a friendly message and accept | |
491 | * failure. */ | |
492 | ||
493 | if (home_not_active) | |
494 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Home of user %s is currently not active, please log in locally first.", ur->user_name); | |
495 | if (home_locked) | |
496 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Home of user %s is currently locked, please unlock locally first.", ur->user_name); | |
497 | ||
498 | pam_syslog(handle, please_authenticate ? LOG_ERR : LOG_DEBUG, "Failed to prompt for password/prompt."); | |
499 | ||
500 | return home_not_active || home_locked ? PAM_PERM_DENIED : PAM_CONV_ERR; | |
501 | } | |
502 | if (r != PAM_SUCCESS) | |
503 | return r; | |
504 | } | |
505 | ||
506 | } else { | |
507 | int fd; | |
508 | ||
509 | r = sd_bus_message_read(reply, "h", &fd); | |
510 | if (r < 0) | |
511 | return pam_bus_log_parse_error(handle, r); | |
512 | ||
513 | acquired_fd = fcntl(fd, F_DUPFD_CLOEXEC, 3); | |
514 | if (acquired_fd < 0) { | |
515 | pam_syslog(handle, LOG_ERR, "Failed to duplicate acquired fd: %s", bus_error_message(&error, r)); | |
516 | return PAM_SERVICE_ERR; | |
517 | } | |
518 | ||
519 | break; | |
520 | } | |
521 | ||
522 | if (++n_attempts >= 5) { | |
523 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Too many unsuccessful login attempts for user %s, refusing.", ur->user_name); | |
524 | pam_syslog(handle, LOG_ERR, "Failed to acquire home for user %s: %s", ur->user_name, bus_error_message(&error, r)); | |
525 | return PAM_MAXTRIES; | |
526 | } | |
527 | ||
528 | /* Try again, this time with authentication if we didn't do that before. */ | |
529 | do_auth = true; | |
530 | } | |
531 | ||
532 | r = pam_set_data(handle, "systemd-home-fd", FD_TO_PTR(acquired_fd), cleanup_home_fd); | |
533 | if (r < 0) { | |
534 | pam_syslog(handle, LOG_ERR, "Failed to set PAM bus data: %s", pam_strerror(handle, r)); | |
535 | return r; | |
536 | } | |
537 | TAKE_FD(acquired_fd); | |
538 | ||
539 | if (do_auth) { | |
540 | /* We likely just activated the home directory, let's flush out the user record, since a | |
541 | * newer embedded user record might have been acquired from the activation. */ | |
542 | ||
543 | r = release_user_record(handle); | |
544 | if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) | |
545 | return r; | |
546 | } | |
547 | ||
548 | pam_syslog(handle, LOG_NOTICE, "Home for user %s successfully acquired.", ur->user_name); | |
549 | ||
550 | return PAM_SUCCESS; | |
551 | } | |
552 | ||
553 | static int release_home_fd(pam_handle_t *handle) { | |
554 | const void *home_fd_ptr = NULL; | |
555 | int r; | |
556 | ||
557 | r = pam_get_data(handle, "systemd-home-fd", &home_fd_ptr); | |
558 | if (r == PAM_NO_MODULE_DATA || PTR_TO_FD(home_fd_ptr) < 0) | |
559 | return PAM_NO_MODULE_DATA; | |
560 | ||
561 | r = pam_set_data(handle, "systemd-home-fd", NULL, NULL); | |
562 | if (r != PAM_SUCCESS) | |
563 | pam_syslog(handle, LOG_ERR, "Failed to release PAM home reference fd: %s", pam_strerror(handle, r)); | |
564 | ||
565 | return r; | |
566 | } | |
567 | ||
568 | _public_ PAM_EXTERN int pam_sm_authenticate( | |
569 | pam_handle_t *handle, | |
570 | int flags, | |
571 | int argc, const char **argv) { | |
572 | ||
573 | bool debug = false, suspend_please = false; | |
574 | ||
575 | if (parse_argv(handle, | |
576 | argc, argv, | |
577 | &suspend_please, | |
578 | &debug) < 0) | |
579 | return PAM_AUTH_ERR; | |
580 | ||
581 | if (debug) | |
582 | pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed authenticating"); | |
583 | ||
584 | return acquire_home(handle, /* please_authenticate= */ true, suspend_please, debug); | |
585 | } | |
586 | ||
587 | _public_ PAM_EXTERN int pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv) { | |
588 | return PAM_SUCCESS; | |
589 | } | |
590 | ||
591 | _public_ PAM_EXTERN int pam_sm_open_session( | |
592 | pam_handle_t *handle, | |
593 | int flags, | |
594 | int argc, const char **argv) { | |
595 | ||
596 | bool debug = false, suspend_please = false; | |
597 | int r; | |
598 | ||
599 | if (parse_argv(handle, | |
600 | argc, argv, | |
601 | &suspend_please, | |
602 | &debug) < 0) | |
603 | return PAM_SESSION_ERR; | |
604 | ||
605 | if (debug) | |
606 | pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed session start"); | |
607 | ||
608 | r = acquire_home(handle, /* please_authenticate = */ false, suspend_please, debug); | |
609 | if (r == PAM_USER_UNKNOWN) /* Not managed by us? Don't complain. */ | |
610 | return PAM_SUCCESS; | |
611 | if (r != PAM_SUCCESS) | |
612 | return r; | |
613 | ||
614 | r = pam_putenv(handle, "SYSTEMD_HOME=1"); | |
615 | if (r != PAM_SUCCESS) { | |
616 | pam_syslog(handle, LOG_ERR, "Failed to set PAM environment variable $SYSTEMD_HOME: %s", pam_strerror(handle, r)); | |
617 | return r; | |
618 | } | |
619 | ||
620 | /* Let's release the D-Bus connection, after all the session might live quite a long time, and we are | |
621 | * not going to process the bus connection in that time, so let's better close before the daemon | |
622 | * kicks us off because we are not processing anything. */ | |
623 | (void) pam_release_bus_connection(handle); | |
624 | return PAM_SUCCESS; | |
625 | } | |
626 | ||
627 | _public_ PAM_EXTERN int pam_sm_close_session( | |
628 | pam_handle_t *handle, | |
629 | int flags, | |
630 | int argc, const char **argv) { | |
631 | ||
632 | _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; | |
633 | _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; | |
634 | _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; | |
635 | const char *username = NULL; | |
636 | bool debug = false; | |
637 | int r; | |
638 | ||
639 | if (parse_argv(handle, | |
640 | argc, argv, | |
641 | NULL, | |
642 | &debug) < 0) | |
643 | return PAM_SESSION_ERR; | |
644 | ||
645 | if (debug) | |
646 | pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed session end"); | |
647 | ||
648 | /* Let's explicitly drop the reference to the homed session, so that the subsequent ReleaseHome() | |
649 | * call will be able to do its thing. */ | |
650 | r = release_home_fd(handle); | |
651 | if (r == PAM_NO_MODULE_DATA) /* Nothing to do, we never acquired an fd */ | |
652 | return PAM_SUCCESS; | |
653 | if (r != PAM_SUCCESS) | |
654 | return r; | |
655 | ||
656 | r = pam_get_user(handle, &username, NULL); | |
657 | if (r != PAM_SUCCESS) { | |
658 | pam_syslog(handle, LOG_ERR, "Failed to get user name: %s", pam_strerror(handle, r)); | |
659 | return r; | |
660 | } | |
661 | ||
662 | r = pam_acquire_bus_connection(handle, &bus); | |
663 | if (r != PAM_SUCCESS) | |
664 | return r; | |
665 | ||
ea7cbf5b | 666 | r = bus_message_new_method_call(bus, &m, &home_mgr, "ReleaseHome"); |
26cf9fb7 LP |
667 | if (r < 0) |
668 | return pam_bus_log_create_error(handle, r); | |
669 | ||
670 | r = sd_bus_message_append(m, "s", username); | |
671 | if (r < 0) | |
672 | return pam_bus_log_create_error(handle, r); | |
673 | ||
674 | r = sd_bus_call(bus, m, HOME_SLOW_BUS_CALL_TIMEOUT_USEC, &error, NULL); | |
675 | if (r < 0) { | |
676 | if (sd_bus_error_has_name(&error, BUS_ERROR_HOME_BUSY)) | |
677 | pam_syslog(handle, LOG_NOTICE, "Not deactivating home directory of %s, as it is still used.", username); | |
678 | else { | |
679 | pam_syslog(handle, LOG_ERR, "Failed to release user home: %s", bus_error_message(&error, r)); | |
680 | return PAM_SESSION_ERR; | |
681 | } | |
682 | } | |
683 | ||
684 | return PAM_SUCCESS; | |
685 | } | |
686 | ||
687 | _public_ PAM_EXTERN int pam_sm_acct_mgmt( | |
688 | pam_handle_t *handle, | |
689 | int flags, | |
690 | int argc, | |
691 | const char **argv) { | |
692 | ||
693 | _cleanup_(user_record_unrefp) UserRecord *ur = NULL; | |
694 | bool debug = false, please_suspend = false; | |
695 | usec_t t; | |
696 | int r; | |
697 | ||
698 | if (parse_argv(handle, | |
699 | argc, argv, | |
700 | &please_suspend, | |
701 | &debug) < 0) | |
702 | return PAM_AUTH_ERR; | |
703 | ||
704 | if (debug) | |
705 | pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed account management"); | |
706 | ||
707 | r = acquire_home(handle, /* please_authenticate = */ false, please_suspend, debug); | |
708 | if (r == PAM_USER_UNKNOWN) | |
709 | return PAM_SUCCESS; /* we don't have anything to say about users we don't manage */ | |
710 | if (r != PAM_SUCCESS) | |
711 | return r; | |
712 | ||
713 | r = acquire_user_record(handle, &ur); | |
714 | if (r != PAM_SUCCESS) | |
715 | return r; | |
716 | ||
717 | r = user_record_test_blocked(ur); | |
718 | switch (r) { | |
719 | ||
720 | case -ESTALE: | |
721 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record is newer than current system time, prohibiting access."); | |
722 | return PAM_ACCT_EXPIRED; | |
723 | ||
724 | case -ENOLCK: | |
725 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record is blocked, prohibiting access."); | |
726 | return PAM_ACCT_EXPIRED; | |
727 | ||
728 | case -EL2HLT: | |
729 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record is not valid yet, prohibiting access."); | |
730 | return PAM_ACCT_EXPIRED; | |
731 | ||
732 | case -EL3HLT: | |
733 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record is not valid anymore, prohibiting access."); | |
734 | return PAM_ACCT_EXPIRED; | |
735 | ||
736 | default: | |
737 | if (r < 0) { | |
738 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record not valid, prohibiting access."); | |
739 | return PAM_ACCT_EXPIRED; | |
740 | } | |
741 | ||
742 | break; | |
743 | } | |
744 | ||
745 | t = user_record_ratelimit_next_try(ur); | |
746 | if (t != USEC_INFINITY) { | |
747 | usec_t n = now(CLOCK_REALTIME); | |
748 | ||
749 | if (t > n) { | |
750 | char buf[FORMAT_TIMESPAN_MAX]; | |
751 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Too many logins, try again in %s.", | |
752 | format_timespan(buf, sizeof(buf), t - n, USEC_PER_SEC)); | |
753 | ||
754 | return PAM_MAXTRIES; | |
755 | } | |
756 | } | |
757 | ||
758 | r = user_record_test_password_change_required(ur); | |
759 | switch (r) { | |
760 | ||
761 | case -EKEYREVOKED: | |
762 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password change required."); | |
763 | return PAM_NEW_AUTHTOK_REQD; | |
764 | ||
765 | case -EOWNERDEAD: | |
766 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password expired, change requird."); | |
767 | return PAM_NEW_AUTHTOK_REQD; | |
768 | ||
769 | case -EKEYREJECTED: | |
770 | /* Strictly speaking this is only about password expiration, and we might want to allow | |
771 | * authentication via PKCS#11 or so, but let's ignore this fine distinction for now. */ | |
772 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password is expired, but can't change, refusing login."); | |
773 | return PAM_AUTHTOK_EXPIRED; | |
774 | ||
775 | case -EKEYEXPIRED: | |
776 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password will expire soon, please change."); | |
777 | break; | |
778 | ||
779 | case -EROFS: | |
780 | /* All good, just means the password if we wanted to change we couldn't, but we don't need to */ | |
781 | break; | |
782 | ||
783 | default: | |
784 | if (r < 0) { | |
785 | (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record not valid, prohibiting access."); | |
786 | return PAM_AUTHTOK_EXPIRED; | |
787 | } | |
788 | ||
789 | break; | |
790 | } | |
791 | ||
792 | return PAM_SUCCESS; | |
793 | } | |
794 | ||
795 | _public_ PAM_EXTERN int pam_sm_chauthtok( | |
796 | pam_handle_t *handle, | |
797 | int flags, | |
798 | int argc, | |
799 | const char **argv) { | |
800 | ||
801 | _cleanup_(user_record_unrefp) UserRecord *ur = NULL, *old_secret = NULL, *new_secret = NULL; | |
802 | const char *old_password = NULL, *new_password = NULL; | |
803 | _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; | |
804 | unsigned n_attempts = 0; | |
805 | bool debug = false; | |
806 | int r; | |
807 | ||
808 | if (parse_argv(handle, | |
809 | argc, argv, | |
810 | NULL, | |
811 | &debug) < 0) | |
812 | return PAM_AUTH_ERR; | |
813 | ||
814 | if (debug) | |
815 | pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed account management"); | |
816 | ||
817 | r = pam_acquire_bus_connection(handle, &bus); | |
818 | if (r != PAM_SUCCESS) | |
819 | return r; | |
820 | ||
821 | r = acquire_user_record(handle, &ur); | |
822 | if (r != PAM_SUCCESS) | |
823 | return r; | |
824 | ||
825 | /* Start with cached credentials */ | |
826 | r = pam_get_item(handle, PAM_OLDAUTHTOK, (const void**) &old_password); | |
827 | if (!IN_SET(r, PAM_BAD_ITEM, PAM_SUCCESS)) { | |
828 | pam_syslog(handle, LOG_ERR, "Failed to get old password: %s", pam_strerror(handle, r)); | |
829 | return r; | |
830 | } | |
831 | r = pam_get_item(handle, PAM_AUTHTOK, (const void**) &new_password); | |
832 | if (!IN_SET(r, PAM_BAD_ITEM, PAM_SUCCESS)) { | |
833 | pam_syslog(handle, LOG_ERR, "Failed to get cached password: %s", pam_strerror(handle, r)); | |
834 | return r; | |
835 | } | |
836 | ||
837 | if (isempty(new_password)) { | |
838 | /* No, it's not cached, then let's ask for the password and its verification, and cache | |
839 | * it. */ | |
840 | ||
841 | r = pam_get_authtok_noverify(handle, &new_password, "New password: "); | |
842 | if (r != PAM_SUCCESS) { | |
843 | pam_syslog(handle, LOG_ERR, "Failed to get new password: %s", pam_strerror(handle, r)); | |
844 | return r; | |
845 | } | |
846 | if (isempty(new_password)) { | |
847 | pam_syslog(handle, LOG_DEBUG, "Password request aborted."); | |
848 | return PAM_AUTHTOK_ERR; | |
849 | } | |
850 | ||
851 | r = pam_get_authtok_verify(handle, &new_password, "new password: "); /* Lower case, since PAM prefixes 'Repeat' */ | |
852 | if (r != PAM_SUCCESS) { | |
853 | pam_syslog(handle, LOG_ERR, "Failed to get password again: %s", pam_strerror(handle, r)); | |
854 | return r; | |
855 | } | |
856 | ||
857 | // FIXME: pam_pwquality will ask for the password a third time. It really shouldn't do | |
858 | // that, and instead assume the password was already verified once when it is found to be | |
859 | // cached already. needs to be fixed in pam_pwquality | |
860 | } | |
861 | ||
862 | /* Now everything is cached and checked, let's exit from the preliminary check */ | |
863 | if (FLAGS_SET(flags, PAM_PRELIM_CHECK)) | |
864 | return PAM_SUCCESS; | |
865 | ||
26cf9fb7 LP |
866 | old_secret = user_record_new(); |
867 | if (!old_secret) | |
868 | return pam_log_oom(handle); | |
869 | ||
870 | if (!isempty(old_password)) { | |
871 | r = user_record_set_password(old_secret, STRV_MAKE(old_password), true); | |
872 | if (r < 0) { | |
873 | pam_syslog(handle, LOG_ERR, "Failed to store old password: %s", strerror_safe(r)); | |
874 | return PAM_SERVICE_ERR; | |
875 | } | |
876 | } | |
877 | ||
878 | new_secret = user_record_new(); | |
879 | if (!new_secret) | |
880 | return pam_log_oom(handle); | |
881 | ||
882 | r = user_record_set_password(new_secret, STRV_MAKE(new_password), true); | |
883 | if (r < 0) { | |
884 | pam_syslog(handle, LOG_ERR, "Failed to store new password: %s", strerror_safe(r)); | |
885 | return PAM_SERVICE_ERR; | |
886 | } | |
887 | ||
888 | for (;;) { | |
889 | _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; | |
890 | _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; | |
891 | ||
ea7cbf5b | 892 | r = bus_message_new_method_call(bus, &m, &home_mgr, "ChangePasswordHome"); |
26cf9fb7 LP |
893 | if (r < 0) |
894 | return pam_bus_log_create_error(handle, r); | |
895 | ||
896 | r = sd_bus_message_append(m, "s", ur->user_name); | |
897 | if (r < 0) | |
898 | return pam_bus_log_create_error(handle, r); | |
899 | ||
900 | r = bus_message_append_secret(m, new_secret); | |
901 | if (r < 0) | |
902 | return pam_bus_log_create_error(handle, r); | |
903 | ||
904 | r = bus_message_append_secret(m, old_secret); | |
905 | if (r < 0) | |
906 | return pam_bus_log_create_error(handle, r); | |
907 | ||
908 | r = sd_bus_call(bus, m, HOME_SLOW_BUS_CALL_TIMEOUT_USEC, &error, NULL); | |
909 | if (r < 0) { | |
910 | r = handle_generic_user_record_error(handle, ur->user_name, old_secret, r, &error); | |
911 | if (r == PAM_CONV_ERR) { | |
912 | pam_syslog(handle, LOG_ERR, "Failed to prompt for password/prompt."); | |
913 | return PAM_CONV_ERR; | |
914 | } | |
915 | if (r != PAM_SUCCESS) | |
916 | return r; | |
917 | } else { | |
918 | pam_syslog(handle, LOG_NOTICE, "Successfully changed password for user %s.", ur->user_name); | |
919 | return PAM_SUCCESS; | |
920 | } | |
921 | ||
922 | if (++n_attempts >= 5) | |
923 | break; | |
924 | ||
925 | /* Try again */ | |
926 | }; | |
927 | ||
928 | pam_syslog(handle, LOG_NOTICE, "Failed to change password for user %s: %m", ur->user_name); | |
929 | return PAM_MAXTRIES; | |
930 | } |